1 //===---- TargetInfo.cpp - Encapsulate target details -----------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // These classes wrap the information about a call or function
11 // definition used to handle ABI compliancy.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "TargetInfo.h"
16 #include "ABIInfo.h"
17 #include "CGCXXABI.h"
18 #include "CodeGenFunction.h"
19 #include "clang/AST/RecordLayout.h"
20 #include "clang/CodeGen/CGFunctionInfo.h"
21 #include "clang/Frontend/CodeGenOptions.h"
22 #include "llvm/ADT/Triple.h"
23 #include "llvm/IR/DataLayout.h"
24 #include "llvm/IR/Type.h"
25 #include "llvm/Support/raw_ostream.h"
26 
27 #include <algorithm>    // std::sort
28 
29 using namespace clang;
30 using namespace CodeGen;
31 
32 static void AssignToArrayRange(CodeGen::CGBuilderTy &Builder,
33                                llvm::Value *Array,
34                                llvm::Value *Value,
35                                unsigned FirstIndex,
36                                unsigned LastIndex) {
37   // Alternatively, we could emit this as a loop in the source.
38   for (unsigned I = FirstIndex; I <= LastIndex; ++I) {
39     llvm::Value *Cell = Builder.CreateConstInBoundsGEP1_32(Array, I);
40     Builder.CreateStore(Value, Cell);
41   }
42 }
43 
44 static bool isAggregateTypeForABI(QualType T) {
45   return !CodeGenFunction::hasScalarEvaluationKind(T) ||
46          T->isMemberFunctionPointerType();
47 }
48 
49 ABIInfo::~ABIInfo() {}
50 
51 static CGCXXABI::RecordArgABI getRecordArgABI(const RecordType *RT,
52                                               CGCXXABI &CXXABI) {
53   const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl());
54   if (!RD)
55     return CGCXXABI::RAA_Default;
56   return CXXABI.getRecordArgABI(RD);
57 }
58 
59 static CGCXXABI::RecordArgABI getRecordArgABI(QualType T,
60                                               CGCXXABI &CXXABI) {
61   const RecordType *RT = T->getAs<RecordType>();
62   if (!RT)
63     return CGCXXABI::RAA_Default;
64   return getRecordArgABI(RT, CXXABI);
65 }
66 
67 CGCXXABI &ABIInfo::getCXXABI() const {
68   return CGT.getCXXABI();
69 }
70 
71 ASTContext &ABIInfo::getContext() const {
72   return CGT.getContext();
73 }
74 
75 llvm::LLVMContext &ABIInfo::getVMContext() const {
76   return CGT.getLLVMContext();
77 }
78 
79 const llvm::DataLayout &ABIInfo::getDataLayout() const {
80   return CGT.getDataLayout();
81 }
82 
83 const TargetInfo &ABIInfo::getTarget() const {
84   return CGT.getTarget();
85 }
86 
87 void ABIArgInfo::dump() const {
88   raw_ostream &OS = llvm::errs();
89   OS << "(ABIArgInfo Kind=";
90   switch (TheKind) {
91   case Direct:
92     OS << "Direct Type=";
93     if (llvm::Type *Ty = getCoerceToType())
94       Ty->print(OS);
95     else
96       OS << "null";
97     break;
98   case Extend:
99     OS << "Extend";
100     break;
101   case Ignore:
102     OS << "Ignore";
103     break;
104   case InAlloca:
105     OS << "InAlloca Offset=" << getInAllocaFieldIndex();
106     break;
107   case Indirect:
108     OS << "Indirect Align=" << getIndirectAlign()
109        << " ByVal=" << getIndirectByVal()
110        << " Realign=" << getIndirectRealign();
111     break;
112   case Expand:
113     OS << "Expand";
114     break;
115   }
116   OS << ")\n";
117 }
118 
119 TargetCodeGenInfo::~TargetCodeGenInfo() { delete Info; }
120 
121 // If someone can figure out a general rule for this, that would be great.
122 // It's probably just doomed to be platform-dependent, though.
123 unsigned TargetCodeGenInfo::getSizeOfUnwindException() const {
124   // Verified for:
125   //   x86-64     FreeBSD, Linux, Darwin
126   //   x86-32     FreeBSD, Linux, Darwin
127   //   PowerPC    Linux, Darwin
128   //   ARM        Darwin (*not* EABI)
129   //   AArch64    Linux
130   return 32;
131 }
132 
133 bool TargetCodeGenInfo::isNoProtoCallVariadic(const CallArgList &args,
134                                      const FunctionNoProtoType *fnType) const {
135   // The following conventions are known to require this to be false:
136   //   x86_stdcall
137   //   MIPS
138   // For everything else, we just prefer false unless we opt out.
139   return false;
140 }
141 
142 void
143 TargetCodeGenInfo::getDependentLibraryOption(llvm::StringRef Lib,
144                                              llvm::SmallString<24> &Opt) const {
145   // This assumes the user is passing a library name like "rt" instead of a
146   // filename like "librt.a/so", and that they don't care whether it's static or
147   // dynamic.
148   Opt = "-l";
149   Opt += Lib;
150 }
151 
152 static bool isEmptyRecord(ASTContext &Context, QualType T, bool AllowArrays);
153 
154 /// isEmptyField - Return true iff a the field is "empty", that is it
155 /// is an unnamed bit-field or an (array of) empty record(s).
156 static bool isEmptyField(ASTContext &Context, const FieldDecl *FD,
157                          bool AllowArrays) {
158   if (FD->isUnnamedBitfield())
159     return true;
160 
161   QualType FT = FD->getType();
162 
163   // Constant arrays of empty records count as empty, strip them off.
164   // Constant arrays of zero length always count as empty.
165   if (AllowArrays)
166     while (const ConstantArrayType *AT = Context.getAsConstantArrayType(FT)) {
167       if (AT->getSize() == 0)
168         return true;
169       FT = AT->getElementType();
170     }
171 
172   const RecordType *RT = FT->getAs<RecordType>();
173   if (!RT)
174     return false;
175 
176   // C++ record fields are never empty, at least in the Itanium ABI.
177   //
178   // FIXME: We should use a predicate for whether this behavior is true in the
179   // current ABI.
180   if (isa<CXXRecordDecl>(RT->getDecl()))
181     return false;
182 
183   return isEmptyRecord(Context, FT, AllowArrays);
184 }
185 
186 /// isEmptyRecord - Return true iff a structure contains only empty
187 /// fields. Note that a structure with a flexible array member is not
188 /// considered empty.
189 static bool isEmptyRecord(ASTContext &Context, QualType T, bool AllowArrays) {
190   const RecordType *RT = T->getAs<RecordType>();
191   if (!RT)
192     return 0;
193   const RecordDecl *RD = RT->getDecl();
194   if (RD->hasFlexibleArrayMember())
195     return false;
196 
197   // If this is a C++ record, check the bases first.
198   if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD))
199     for (const auto &I : CXXRD->bases())
200       if (!isEmptyRecord(Context, I.getType(), true))
201         return false;
202 
203   for (const auto *I : RD->fields())
204     if (!isEmptyField(Context, I, AllowArrays))
205       return false;
206   return true;
207 }
208 
209 /// isSingleElementStruct - Determine if a structure is a "single
210 /// element struct", i.e. it has exactly one non-empty field or
211 /// exactly one field which is itself a single element
212 /// struct. Structures with flexible array members are never
213 /// considered single element structs.
214 ///
215 /// \return The field declaration for the single non-empty field, if
216 /// it exists.
217 static const Type *isSingleElementStruct(QualType T, ASTContext &Context) {
218   const RecordType *RT = T->getAsStructureType();
219   if (!RT)
220     return 0;
221 
222   const RecordDecl *RD = RT->getDecl();
223   if (RD->hasFlexibleArrayMember())
224     return 0;
225 
226   const Type *Found = 0;
227 
228   // If this is a C++ record, check the bases first.
229   if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
230     for (const auto &I : CXXRD->bases()) {
231       // Ignore empty records.
232       if (isEmptyRecord(Context, I.getType(), true))
233         continue;
234 
235       // If we already found an element then this isn't a single-element struct.
236       if (Found)
237         return 0;
238 
239       // If this is non-empty and not a single element struct, the composite
240       // cannot be a single element struct.
241       Found = isSingleElementStruct(I.getType(), Context);
242       if (!Found)
243         return 0;
244     }
245   }
246 
247   // Check for single element.
248   for (const auto *FD : RD->fields()) {
249     QualType FT = FD->getType();
250 
251     // Ignore empty fields.
252     if (isEmptyField(Context, FD, true))
253       continue;
254 
255     // If we already found an element then this isn't a single-element
256     // struct.
257     if (Found)
258       return 0;
259 
260     // Treat single element arrays as the element.
261     while (const ConstantArrayType *AT = Context.getAsConstantArrayType(FT)) {
262       if (AT->getSize().getZExtValue() != 1)
263         break;
264       FT = AT->getElementType();
265     }
266 
267     if (!isAggregateTypeForABI(FT)) {
268       Found = FT.getTypePtr();
269     } else {
270       Found = isSingleElementStruct(FT, Context);
271       if (!Found)
272         return 0;
273     }
274   }
275 
276   // We don't consider a struct a single-element struct if it has
277   // padding beyond the element type.
278   if (Found && Context.getTypeSize(Found) != Context.getTypeSize(T))
279     return 0;
280 
281   return Found;
282 }
283 
284 static bool is32Or64BitBasicType(QualType Ty, ASTContext &Context) {
285   // Treat complex types as the element type.
286   if (const ComplexType *CTy = Ty->getAs<ComplexType>())
287     Ty = CTy->getElementType();
288 
289   // Check for a type which we know has a simple scalar argument-passing
290   // convention without any padding.  (We're specifically looking for 32
291   // and 64-bit integer and integer-equivalents, float, and double.)
292   if (!Ty->getAs<BuiltinType>() && !Ty->hasPointerRepresentation() &&
293       !Ty->isEnumeralType() && !Ty->isBlockPointerType())
294     return false;
295 
296   uint64_t Size = Context.getTypeSize(Ty);
297   return Size == 32 || Size == 64;
298 }
299 
300 /// canExpandIndirectArgument - Test whether an argument type which is to be
301 /// passed indirectly (on the stack) would have the equivalent layout if it was
302 /// expanded into separate arguments. If so, we prefer to do the latter to avoid
303 /// inhibiting optimizations.
304 ///
305 // FIXME: This predicate is missing many cases, currently it just follows
306 // llvm-gcc (checks that all fields are 32-bit or 64-bit primitive types). We
307 // should probably make this smarter, or better yet make the LLVM backend
308 // capable of handling it.
309 static bool canExpandIndirectArgument(QualType Ty, ASTContext &Context) {
310   // We can only expand structure types.
311   const RecordType *RT = Ty->getAs<RecordType>();
312   if (!RT)
313     return false;
314 
315   // We can only expand (C) structures.
316   //
317   // FIXME: This needs to be generalized to handle classes as well.
318   const RecordDecl *RD = RT->getDecl();
319   if (!RD->isStruct() || isa<CXXRecordDecl>(RD))
320     return false;
321 
322   uint64_t Size = 0;
323 
324   for (const auto *FD : RD->fields()) {
325     if (!is32Or64BitBasicType(FD->getType(), Context))
326       return false;
327 
328     // FIXME: Reject bit-fields wholesale; there are two problems, we don't know
329     // how to expand them yet, and the predicate for telling if a bitfield still
330     // counts as "basic" is more complicated than what we were doing previously.
331     if (FD->isBitField())
332       return false;
333 
334     Size += Context.getTypeSize(FD->getType());
335   }
336 
337   // Make sure there are not any holes in the struct.
338   if (Size != Context.getTypeSize(Ty))
339     return false;
340 
341   return true;
342 }
343 
344 namespace {
345 /// DefaultABIInfo - The default implementation for ABI specific
346 /// details. This implementation provides information which results in
347 /// self-consistent and sensible LLVM IR generation, but does not
348 /// conform to any particular ABI.
349 class DefaultABIInfo : public ABIInfo {
350 public:
351   DefaultABIInfo(CodeGen::CodeGenTypes &CGT) : ABIInfo(CGT) {}
352 
353   ABIArgInfo classifyReturnType(QualType RetTy) const;
354   ABIArgInfo classifyArgumentType(QualType RetTy) const;
355 
356   void computeInfo(CGFunctionInfo &FI) const override {
357     if (!getCXXABI().classifyReturnType(FI))
358       FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
359     for (auto &I : FI.arguments())
360       I.info = classifyArgumentType(I.type);
361   }
362 
363   llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
364                          CodeGenFunction &CGF) const override;
365 };
366 
367 class DefaultTargetCodeGenInfo : public TargetCodeGenInfo {
368 public:
369   DefaultTargetCodeGenInfo(CodeGen::CodeGenTypes &CGT)
370     : TargetCodeGenInfo(new DefaultABIInfo(CGT)) {}
371 };
372 
373 llvm::Value *DefaultABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
374                                        CodeGenFunction &CGF) const {
375   return 0;
376 }
377 
378 ABIArgInfo DefaultABIInfo::classifyArgumentType(QualType Ty) const {
379   if (isAggregateTypeForABI(Ty))
380     return ABIArgInfo::getIndirect(0);
381 
382   // Treat an enum type as its underlying type.
383   if (const EnumType *EnumTy = Ty->getAs<EnumType>())
384     Ty = EnumTy->getDecl()->getIntegerType();
385 
386   return (Ty->isPromotableIntegerType() ?
387           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
388 }
389 
390 ABIArgInfo DefaultABIInfo::classifyReturnType(QualType RetTy) const {
391   if (RetTy->isVoidType())
392     return ABIArgInfo::getIgnore();
393 
394   if (isAggregateTypeForABI(RetTy))
395     return ABIArgInfo::getIndirect(0);
396 
397   // Treat an enum type as its underlying type.
398   if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
399     RetTy = EnumTy->getDecl()->getIntegerType();
400 
401   return (RetTy->isPromotableIntegerType() ?
402           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
403 }
404 
405 //===----------------------------------------------------------------------===//
406 // le32/PNaCl bitcode ABI Implementation
407 //
408 // This is a simplified version of the x86_32 ABI.  Arguments and return values
409 // are always passed on the stack.
410 //===----------------------------------------------------------------------===//
411 
412 class PNaClABIInfo : public ABIInfo {
413  public:
414   PNaClABIInfo(CodeGen::CodeGenTypes &CGT) : ABIInfo(CGT) {}
415 
416   ABIArgInfo classifyReturnType(QualType RetTy) const;
417   ABIArgInfo classifyArgumentType(QualType RetTy) const;
418 
419   void computeInfo(CGFunctionInfo &FI) const override;
420   llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
421                          CodeGenFunction &CGF) const override;
422 };
423 
424 class PNaClTargetCodeGenInfo : public TargetCodeGenInfo {
425  public:
426   PNaClTargetCodeGenInfo(CodeGen::CodeGenTypes &CGT)
427     : TargetCodeGenInfo(new PNaClABIInfo(CGT)) {}
428 };
429 
430 void PNaClABIInfo::computeInfo(CGFunctionInfo &FI) const {
431   if (!getCXXABI().classifyReturnType(FI))
432     FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
433 
434   for (auto &I : FI.arguments())
435     I.info = classifyArgumentType(I.type);
436 }
437 
438 llvm::Value *PNaClABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
439                                        CodeGenFunction &CGF) const {
440   return 0;
441 }
442 
443 /// \brief Classify argument of given type \p Ty.
444 ABIArgInfo PNaClABIInfo::classifyArgumentType(QualType Ty) const {
445   if (isAggregateTypeForABI(Ty)) {
446     if (CGCXXABI::RecordArgABI RAA = getRecordArgABI(Ty, getCXXABI()))
447       return ABIArgInfo::getIndirect(0, RAA == CGCXXABI::RAA_DirectInMemory);
448     return ABIArgInfo::getIndirect(0);
449   } else if (const EnumType *EnumTy = Ty->getAs<EnumType>()) {
450     // Treat an enum type as its underlying type.
451     Ty = EnumTy->getDecl()->getIntegerType();
452   } else if (Ty->isFloatingType()) {
453     // Floating-point types don't go inreg.
454     return ABIArgInfo::getDirect();
455   }
456 
457   return (Ty->isPromotableIntegerType() ?
458           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
459 }
460 
461 ABIArgInfo PNaClABIInfo::classifyReturnType(QualType RetTy) const {
462   if (RetTy->isVoidType())
463     return ABIArgInfo::getIgnore();
464 
465   // In the PNaCl ABI we always return records/structures on the stack.
466   if (isAggregateTypeForABI(RetTy))
467     return ABIArgInfo::getIndirect(0);
468 
469   // Treat an enum type as its underlying type.
470   if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
471     RetTy = EnumTy->getDecl()->getIntegerType();
472 
473   return (RetTy->isPromotableIntegerType() ?
474           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
475 }
476 
477 /// IsX86_MMXType - Return true if this is an MMX type.
478 bool IsX86_MMXType(llvm::Type *IRType) {
479   // Return true if the type is an MMX type <2 x i32>, <4 x i16>, or <8 x i8>.
480   return IRType->isVectorTy() && IRType->getPrimitiveSizeInBits() == 64 &&
481     cast<llvm::VectorType>(IRType)->getElementType()->isIntegerTy() &&
482     IRType->getScalarSizeInBits() != 64;
483 }
484 
485 static llvm::Type* X86AdjustInlineAsmType(CodeGen::CodeGenFunction &CGF,
486                                           StringRef Constraint,
487                                           llvm::Type* Ty) {
488   if ((Constraint == "y" || Constraint == "&y") && Ty->isVectorTy()) {
489     if (cast<llvm::VectorType>(Ty)->getBitWidth() != 64) {
490       // Invalid MMX constraint
491       return 0;
492     }
493 
494     return llvm::Type::getX86_MMXTy(CGF.getLLVMContext());
495   }
496 
497   // No operation needed
498   return Ty;
499 }
500 
501 //===----------------------------------------------------------------------===//
502 // X86-32 ABI Implementation
503 //===----------------------------------------------------------------------===//
504 
505 /// \brief Similar to llvm::CCState, but for Clang.
506 struct CCState {
507   CCState(unsigned CC) : CC(CC), FreeRegs(0) {}
508 
509   unsigned CC;
510   unsigned FreeRegs;
511   unsigned StackOffset;
512   bool UseInAlloca;
513 };
514 
515 /// X86_32ABIInfo - The X86-32 ABI information.
516 class X86_32ABIInfo : public ABIInfo {
517   enum Class {
518     Integer,
519     Float
520   };
521 
522   static const unsigned MinABIStackAlignInBytes = 4;
523 
524   bool IsDarwinVectorABI;
525   bool IsSmallStructInRegABI;
526   bool IsWin32StructABI;
527   unsigned DefaultNumRegisterParameters;
528 
529   static bool isRegisterSize(unsigned Size) {
530     return (Size == 8 || Size == 16 || Size == 32 || Size == 64);
531   }
532 
533   bool shouldReturnTypeInRegister(QualType Ty, ASTContext &Context) const;
534 
535   /// getIndirectResult - Give a source type \arg Ty, return a suitable result
536   /// such that the argument will be passed in memory.
537   ABIArgInfo getIndirectResult(QualType Ty, bool ByVal, CCState &State) const;
538 
539   ABIArgInfo getIndirectReturnResult(CCState &State) const;
540 
541   /// \brief Return the alignment to use for the given type on the stack.
542   unsigned getTypeStackAlignInBytes(QualType Ty, unsigned Align) const;
543 
544   Class classify(QualType Ty) const;
545   ABIArgInfo classifyReturnType(QualType RetTy, CCState &State) const;
546   ABIArgInfo classifyArgumentType(QualType RetTy, CCState &State) const;
547   bool shouldUseInReg(QualType Ty, CCState &State, bool &NeedsPadding) const;
548 
549   /// \brief Rewrite the function info so that all memory arguments use
550   /// inalloca.
551   void rewriteWithInAlloca(CGFunctionInfo &FI) const;
552 
553   void addFieldToArgStruct(SmallVector<llvm::Type *, 6> &FrameFields,
554                            unsigned &StackOffset, ABIArgInfo &Info,
555                            QualType Type) const;
556 
557 public:
558 
559   void computeInfo(CGFunctionInfo &FI) const override;
560   llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
561                          CodeGenFunction &CGF) const override;
562 
563   X86_32ABIInfo(CodeGen::CodeGenTypes &CGT, bool d, bool p, bool w,
564                 unsigned r)
565     : ABIInfo(CGT), IsDarwinVectorABI(d), IsSmallStructInRegABI(p),
566       IsWin32StructABI(w), DefaultNumRegisterParameters(r) {}
567 };
568 
569 class X86_32TargetCodeGenInfo : public TargetCodeGenInfo {
570 public:
571   X86_32TargetCodeGenInfo(CodeGen::CodeGenTypes &CGT,
572       bool d, bool p, bool w, unsigned r)
573     :TargetCodeGenInfo(new X86_32ABIInfo(CGT, d, p, w, r)) {}
574 
575   static bool isStructReturnInRegABI(
576       const llvm::Triple &Triple, const CodeGenOptions &Opts);
577 
578   void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
579                            CodeGen::CodeGenModule &CGM) const override;
580 
581   int getDwarfEHStackPointer(CodeGen::CodeGenModule &CGM) const override {
582     // Darwin uses different dwarf register numbers for EH.
583     if (CGM.getTarget().getTriple().isOSDarwin()) return 5;
584     return 4;
585   }
586 
587   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
588                                llvm::Value *Address) const override;
589 
590   llvm::Type* adjustInlineAsmType(CodeGen::CodeGenFunction &CGF,
591                                   StringRef Constraint,
592                                   llvm::Type* Ty) const override {
593     return X86AdjustInlineAsmType(CGF, Constraint, Ty);
594   }
595 
596   llvm::Constant *
597   getUBSanFunctionSignature(CodeGen::CodeGenModule &CGM) const override {
598     unsigned Sig = (0xeb << 0) |  // jmp rel8
599                    (0x06 << 8) |  //           .+0x08
600                    ('F' << 16) |
601                    ('T' << 24);
602     return llvm::ConstantInt::get(CGM.Int32Ty, Sig);
603   }
604 
605 };
606 
607 }
608 
609 /// shouldReturnTypeInRegister - Determine if the given type should be
610 /// passed in a register (for the Darwin ABI).
611 bool X86_32ABIInfo::shouldReturnTypeInRegister(QualType Ty,
612                                                ASTContext &Context) const {
613   uint64_t Size = Context.getTypeSize(Ty);
614 
615   // Type must be register sized.
616   if (!isRegisterSize(Size))
617     return false;
618 
619   if (Ty->isVectorType()) {
620     // 64- and 128- bit vectors inside structures are not returned in
621     // registers.
622     if (Size == 64 || Size == 128)
623       return false;
624 
625     return true;
626   }
627 
628   // If this is a builtin, pointer, enum, complex type, member pointer, or
629   // member function pointer it is ok.
630   if (Ty->getAs<BuiltinType>() || Ty->hasPointerRepresentation() ||
631       Ty->isAnyComplexType() || Ty->isEnumeralType() ||
632       Ty->isBlockPointerType() || Ty->isMemberPointerType())
633     return true;
634 
635   // Arrays are treated like records.
636   if (const ConstantArrayType *AT = Context.getAsConstantArrayType(Ty))
637     return shouldReturnTypeInRegister(AT->getElementType(), Context);
638 
639   // Otherwise, it must be a record type.
640   const RecordType *RT = Ty->getAs<RecordType>();
641   if (!RT) return false;
642 
643   // FIXME: Traverse bases here too.
644 
645   // Structure types are passed in register if all fields would be
646   // passed in a register.
647   for (const auto *FD : RT->getDecl()->fields()) {
648     // Empty fields are ignored.
649     if (isEmptyField(Context, FD, true))
650       continue;
651 
652     // Check fields recursively.
653     if (!shouldReturnTypeInRegister(FD->getType(), Context))
654       return false;
655   }
656   return true;
657 }
658 
659 ABIArgInfo X86_32ABIInfo::getIndirectReturnResult(CCState &State) const {
660   // If the return value is indirect, then the hidden argument is consuming one
661   // integer register.
662   if (State.FreeRegs) {
663     --State.FreeRegs;
664     return ABIArgInfo::getIndirectInReg(/*Align=*/0, /*ByVal=*/false);
665   }
666   return ABIArgInfo::getIndirect(/*Align=*/0, /*ByVal=*/false);
667 }
668 
669 ABIArgInfo X86_32ABIInfo::classifyReturnType(QualType RetTy, CCState &State) const {
670   if (RetTy->isVoidType())
671     return ABIArgInfo::getIgnore();
672 
673   if (const VectorType *VT = RetTy->getAs<VectorType>()) {
674     // On Darwin, some vectors are returned in registers.
675     if (IsDarwinVectorABI) {
676       uint64_t Size = getContext().getTypeSize(RetTy);
677 
678       // 128-bit vectors are a special case; they are returned in
679       // registers and we need to make sure to pick a type the LLVM
680       // backend will like.
681       if (Size == 128)
682         return ABIArgInfo::getDirect(llvm::VectorType::get(
683                   llvm::Type::getInt64Ty(getVMContext()), 2));
684 
685       // Always return in register if it fits in a general purpose
686       // register, or if it is 64 bits and has a single element.
687       if ((Size == 8 || Size == 16 || Size == 32) ||
688           (Size == 64 && VT->getNumElements() == 1))
689         return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),
690                                                             Size));
691 
692       return getIndirectReturnResult(State);
693     }
694 
695     return ABIArgInfo::getDirect();
696   }
697 
698   if (isAggregateTypeForABI(RetTy)) {
699     if (const RecordType *RT = RetTy->getAs<RecordType>()) {
700       // Structures with flexible arrays are always indirect.
701       if (RT->getDecl()->hasFlexibleArrayMember())
702         return getIndirectReturnResult(State);
703     }
704 
705     // If specified, structs and unions are always indirect.
706     if (!IsSmallStructInRegABI && !RetTy->isAnyComplexType())
707       return getIndirectReturnResult(State);
708 
709     // Small structures which are register sized are generally returned
710     // in a register.
711     if (shouldReturnTypeInRegister(RetTy, getContext())) {
712       uint64_t Size = getContext().getTypeSize(RetTy);
713 
714       // As a special-case, if the struct is a "single-element" struct, and
715       // the field is of type "float" or "double", return it in a
716       // floating-point register. (MSVC does not apply this special case.)
717       // We apply a similar transformation for pointer types to improve the
718       // quality of the generated IR.
719       if (const Type *SeltTy = isSingleElementStruct(RetTy, getContext()))
720         if ((!IsWin32StructABI && SeltTy->isRealFloatingType())
721             || SeltTy->hasPointerRepresentation())
722           return ABIArgInfo::getDirect(CGT.ConvertType(QualType(SeltTy, 0)));
723 
724       // FIXME: We should be able to narrow this integer in cases with dead
725       // padding.
726       return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),Size));
727     }
728 
729     return getIndirectReturnResult(State);
730   }
731 
732   // Treat an enum type as its underlying type.
733   if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
734     RetTy = EnumTy->getDecl()->getIntegerType();
735 
736   return (RetTy->isPromotableIntegerType() ?
737           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
738 }
739 
740 static bool isSSEVectorType(ASTContext &Context, QualType Ty) {
741   return Ty->getAs<VectorType>() && Context.getTypeSize(Ty) == 128;
742 }
743 
744 static bool isRecordWithSSEVectorType(ASTContext &Context, QualType Ty) {
745   const RecordType *RT = Ty->getAs<RecordType>();
746   if (!RT)
747     return 0;
748   const RecordDecl *RD = RT->getDecl();
749 
750   // If this is a C++ record, check the bases first.
751   if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD))
752     for (const auto &I : CXXRD->bases())
753       if (!isRecordWithSSEVectorType(Context, I.getType()))
754         return false;
755 
756   for (const auto *i : RD->fields()) {
757     QualType FT = i->getType();
758 
759     if (isSSEVectorType(Context, FT))
760       return true;
761 
762     if (isRecordWithSSEVectorType(Context, FT))
763       return true;
764   }
765 
766   return false;
767 }
768 
769 unsigned X86_32ABIInfo::getTypeStackAlignInBytes(QualType Ty,
770                                                  unsigned Align) const {
771   // Otherwise, if the alignment is less than or equal to the minimum ABI
772   // alignment, just use the default; the backend will handle this.
773   if (Align <= MinABIStackAlignInBytes)
774     return 0; // Use default alignment.
775 
776   // On non-Darwin, the stack type alignment is always 4.
777   if (!IsDarwinVectorABI) {
778     // Set explicit alignment, since we may need to realign the top.
779     return MinABIStackAlignInBytes;
780   }
781 
782   // Otherwise, if the type contains an SSE vector type, the alignment is 16.
783   if (Align >= 16 && (isSSEVectorType(getContext(), Ty) ||
784                       isRecordWithSSEVectorType(getContext(), Ty)))
785     return 16;
786 
787   return MinABIStackAlignInBytes;
788 }
789 
790 ABIArgInfo X86_32ABIInfo::getIndirectResult(QualType Ty, bool ByVal,
791                                             CCState &State) const {
792   if (!ByVal) {
793     if (State.FreeRegs) {
794       --State.FreeRegs; // Non-byval indirects just use one pointer.
795       return ABIArgInfo::getIndirectInReg(0, false);
796     }
797     return ABIArgInfo::getIndirect(0, false);
798   }
799 
800   // Compute the byval alignment.
801   unsigned TypeAlign = getContext().getTypeAlign(Ty) / 8;
802   unsigned StackAlign = getTypeStackAlignInBytes(Ty, TypeAlign);
803   if (StackAlign == 0)
804     return ABIArgInfo::getIndirect(4, /*ByVal=*/true);
805 
806   // If the stack alignment is less than the type alignment, realign the
807   // argument.
808   bool Realign = TypeAlign > StackAlign;
809   return ABIArgInfo::getIndirect(StackAlign, /*ByVal=*/true, Realign);
810 }
811 
812 X86_32ABIInfo::Class X86_32ABIInfo::classify(QualType Ty) const {
813   const Type *T = isSingleElementStruct(Ty, getContext());
814   if (!T)
815     T = Ty.getTypePtr();
816 
817   if (const BuiltinType *BT = T->getAs<BuiltinType>()) {
818     BuiltinType::Kind K = BT->getKind();
819     if (K == BuiltinType::Float || K == BuiltinType::Double)
820       return Float;
821   }
822   return Integer;
823 }
824 
825 bool X86_32ABIInfo::shouldUseInReg(QualType Ty, CCState &State,
826                                    bool &NeedsPadding) const {
827   NeedsPadding = false;
828   Class C = classify(Ty);
829   if (C == Float)
830     return false;
831 
832   unsigned Size = getContext().getTypeSize(Ty);
833   unsigned SizeInRegs = (Size + 31) / 32;
834 
835   if (SizeInRegs == 0)
836     return false;
837 
838   if (SizeInRegs > State.FreeRegs) {
839     State.FreeRegs = 0;
840     return false;
841   }
842 
843   State.FreeRegs -= SizeInRegs;
844 
845   if (State.CC == llvm::CallingConv::X86_FastCall) {
846     if (Size > 32)
847       return false;
848 
849     if (Ty->isIntegralOrEnumerationType())
850       return true;
851 
852     if (Ty->isPointerType())
853       return true;
854 
855     if (Ty->isReferenceType())
856       return true;
857 
858     if (State.FreeRegs)
859       NeedsPadding = true;
860 
861     return false;
862   }
863 
864   return true;
865 }
866 
867 ABIArgInfo X86_32ABIInfo::classifyArgumentType(QualType Ty,
868                                                CCState &State) const {
869   // FIXME: Set alignment on indirect arguments.
870   if (isAggregateTypeForABI(Ty)) {
871     if (const RecordType *RT = Ty->getAs<RecordType>()) {
872       // Check with the C++ ABI first.
873       CGCXXABI::RecordArgABI RAA = getRecordArgABI(RT, getCXXABI());
874       if (RAA == CGCXXABI::RAA_Indirect) {
875         return getIndirectResult(Ty, false, State);
876       } else if (RAA == CGCXXABI::RAA_DirectInMemory) {
877         // The field index doesn't matter, we'll fix it up later.
878         return ABIArgInfo::getInAlloca(/*FieldIndex=*/0);
879       }
880 
881       // Structs are always byval on win32, regardless of what they contain.
882       if (IsWin32StructABI)
883         return getIndirectResult(Ty, true, State);
884 
885       // Structures with flexible arrays are always indirect.
886       if (RT->getDecl()->hasFlexibleArrayMember())
887         return getIndirectResult(Ty, true, State);
888     }
889 
890     // Ignore empty structs/unions.
891     if (isEmptyRecord(getContext(), Ty, true))
892       return ABIArgInfo::getIgnore();
893 
894     llvm::LLVMContext &LLVMContext = getVMContext();
895     llvm::IntegerType *Int32 = llvm::Type::getInt32Ty(LLVMContext);
896     bool NeedsPadding;
897     if (shouldUseInReg(Ty, State, NeedsPadding)) {
898       unsigned SizeInRegs = (getContext().getTypeSize(Ty) + 31) / 32;
899       SmallVector<llvm::Type*, 3> Elements(SizeInRegs, Int32);
900       llvm::Type *Result = llvm::StructType::get(LLVMContext, Elements);
901       return ABIArgInfo::getDirectInReg(Result);
902     }
903     llvm::IntegerType *PaddingType = NeedsPadding ? Int32 : 0;
904 
905     // Expand small (<= 128-bit) record types when we know that the stack layout
906     // of those arguments will match the struct. This is important because the
907     // LLVM backend isn't smart enough to remove byval, which inhibits many
908     // optimizations.
909     if (getContext().getTypeSize(Ty) <= 4*32 &&
910         canExpandIndirectArgument(Ty, getContext()))
911       return ABIArgInfo::getExpandWithPadding(
912           State.CC == llvm::CallingConv::X86_FastCall, PaddingType);
913 
914     return getIndirectResult(Ty, true, State);
915   }
916 
917   if (const VectorType *VT = Ty->getAs<VectorType>()) {
918     // On Darwin, some vectors are passed in memory, we handle this by passing
919     // it as an i8/i16/i32/i64.
920     if (IsDarwinVectorABI) {
921       uint64_t Size = getContext().getTypeSize(Ty);
922       if ((Size == 8 || Size == 16 || Size == 32) ||
923           (Size == 64 && VT->getNumElements() == 1))
924         return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),
925                                                             Size));
926     }
927 
928     if (IsX86_MMXType(CGT.ConvertType(Ty)))
929       return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(), 64));
930 
931     return ABIArgInfo::getDirect();
932   }
933 
934 
935   if (const EnumType *EnumTy = Ty->getAs<EnumType>())
936     Ty = EnumTy->getDecl()->getIntegerType();
937 
938   bool NeedsPadding;
939   bool InReg = shouldUseInReg(Ty, State, NeedsPadding);
940 
941   if (Ty->isPromotableIntegerType()) {
942     if (InReg)
943       return ABIArgInfo::getExtendInReg();
944     return ABIArgInfo::getExtend();
945   }
946   if (InReg)
947     return ABIArgInfo::getDirectInReg();
948   return ABIArgInfo::getDirect();
949 }
950 
951 void X86_32ABIInfo::computeInfo(CGFunctionInfo &FI) const {
952   CCState State(FI.getCallingConvention());
953   if (State.CC == llvm::CallingConv::X86_FastCall)
954     State.FreeRegs = 2;
955   else if (FI.getHasRegParm())
956     State.FreeRegs = FI.getRegParm();
957   else
958     State.FreeRegs = DefaultNumRegisterParameters;
959 
960   if (!getCXXABI().classifyReturnType(FI))
961     FI.getReturnInfo() = classifyReturnType(FI.getReturnType(), State);
962 
963   bool UsedInAlloca = false;
964   for (auto &I : FI.arguments()) {
965     I.info = classifyArgumentType(I.type, State);
966     UsedInAlloca |= (I.info.getKind() == ABIArgInfo::InAlloca);
967   }
968 
969   // If we needed to use inalloca for any argument, do a second pass and rewrite
970   // all the memory arguments to use inalloca.
971   if (UsedInAlloca)
972     rewriteWithInAlloca(FI);
973 }
974 
975 void
976 X86_32ABIInfo::addFieldToArgStruct(SmallVector<llvm::Type *, 6> &FrameFields,
977                                    unsigned &StackOffset,
978                                    ABIArgInfo &Info, QualType Type) const {
979   assert(StackOffset % 4U == 0 && "unaligned inalloca struct");
980   Info = ABIArgInfo::getInAlloca(FrameFields.size());
981   FrameFields.push_back(CGT.ConvertTypeForMem(Type));
982   StackOffset += getContext().getTypeSizeInChars(Type).getQuantity();
983 
984   // Insert padding bytes to respect alignment.  For x86_32, each argument is 4
985   // byte aligned.
986   if (StackOffset % 4U) {
987     unsigned OldOffset = StackOffset;
988     StackOffset = llvm::RoundUpToAlignment(StackOffset, 4U);
989     unsigned NumBytes = StackOffset - OldOffset;
990     assert(NumBytes);
991     llvm::Type *Ty = llvm::Type::getInt8Ty(getVMContext());
992     Ty = llvm::ArrayType::get(Ty, NumBytes);
993     FrameFields.push_back(Ty);
994   }
995 }
996 
997 void X86_32ABIInfo::rewriteWithInAlloca(CGFunctionInfo &FI) const {
998   assert(IsWin32StructABI && "inalloca only supported on win32");
999 
1000   // Build a packed struct type for all of the arguments in memory.
1001   SmallVector<llvm::Type *, 6> FrameFields;
1002 
1003   unsigned StackOffset = 0;
1004 
1005   // Put the sret parameter into the inalloca struct if it's in memory.
1006   ABIArgInfo &Ret = FI.getReturnInfo();
1007   if (Ret.isIndirect() && !Ret.getInReg()) {
1008     CanQualType PtrTy = getContext().getPointerType(FI.getReturnType());
1009     addFieldToArgStruct(FrameFields, StackOffset, Ret, PtrTy);
1010     // On Windows, the hidden sret parameter is always returned in eax.
1011     Ret.setInAllocaSRet(IsWin32StructABI);
1012   }
1013 
1014   // Skip the 'this' parameter in ecx.
1015   CGFunctionInfo::arg_iterator I = FI.arg_begin(), E = FI.arg_end();
1016   if (FI.getCallingConvention() == llvm::CallingConv::X86_ThisCall)
1017     ++I;
1018 
1019   // Put arguments passed in memory into the struct.
1020   for (; I != E; ++I) {
1021 
1022     // Leave ignored and inreg arguments alone.
1023     switch (I->info.getKind()) {
1024     case ABIArgInfo::Indirect:
1025       assert(I->info.getIndirectByVal());
1026       break;
1027     case ABIArgInfo::Ignore:
1028       continue;
1029     case ABIArgInfo::Direct:
1030     case ABIArgInfo::Extend:
1031       if (I->info.getInReg())
1032         continue;
1033       break;
1034     default:
1035       break;
1036     }
1037 
1038     addFieldToArgStruct(FrameFields, StackOffset, I->info, I->type);
1039   }
1040 
1041   FI.setArgStruct(llvm::StructType::get(getVMContext(), FrameFields,
1042                                         /*isPacked=*/true));
1043 }
1044 
1045 llvm::Value *X86_32ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
1046                                       CodeGenFunction &CGF) const {
1047   llvm::Type *BPP = CGF.Int8PtrPtrTy;
1048 
1049   CGBuilderTy &Builder = CGF.Builder;
1050   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP,
1051                                                        "ap");
1052   llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
1053 
1054   // Compute if the address needs to be aligned
1055   unsigned Align = CGF.getContext().getTypeAlignInChars(Ty).getQuantity();
1056   Align = getTypeStackAlignInBytes(Ty, Align);
1057   Align = std::max(Align, 4U);
1058   if (Align > 4) {
1059     // addr = (addr + align - 1) & -align;
1060     llvm::Value *Offset =
1061       llvm::ConstantInt::get(CGF.Int32Ty, Align - 1);
1062     Addr = CGF.Builder.CreateGEP(Addr, Offset);
1063     llvm::Value *AsInt = CGF.Builder.CreatePtrToInt(Addr,
1064                                                     CGF.Int32Ty);
1065     llvm::Value *Mask = llvm::ConstantInt::get(CGF.Int32Ty, -Align);
1066     Addr = CGF.Builder.CreateIntToPtr(CGF.Builder.CreateAnd(AsInt, Mask),
1067                                       Addr->getType(),
1068                                       "ap.cur.aligned");
1069   }
1070 
1071   llvm::Type *PTy =
1072     llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
1073   llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy);
1074 
1075   uint64_t Offset =
1076     llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, Align);
1077   llvm::Value *NextAddr =
1078     Builder.CreateGEP(Addr, llvm::ConstantInt::get(CGF.Int32Ty, Offset),
1079                       "ap.next");
1080   Builder.CreateStore(NextAddr, VAListAddrAsBPP);
1081 
1082   return AddrTyped;
1083 }
1084 
1085 void X86_32TargetCodeGenInfo::SetTargetAttributes(const Decl *D,
1086                                                   llvm::GlobalValue *GV,
1087                                             CodeGen::CodeGenModule &CGM) const {
1088   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
1089     if (FD->hasAttr<X86ForceAlignArgPointerAttr>()) {
1090       // Get the LLVM function.
1091       llvm::Function *Fn = cast<llvm::Function>(GV);
1092 
1093       // Now add the 'alignstack' attribute with a value of 16.
1094       llvm::AttrBuilder B;
1095       B.addStackAlignmentAttr(16);
1096       Fn->addAttributes(llvm::AttributeSet::FunctionIndex,
1097                       llvm::AttributeSet::get(CGM.getLLVMContext(),
1098                                               llvm::AttributeSet::FunctionIndex,
1099                                               B));
1100     }
1101   }
1102 }
1103 
1104 bool X86_32TargetCodeGenInfo::initDwarfEHRegSizeTable(
1105                                                CodeGen::CodeGenFunction &CGF,
1106                                                llvm::Value *Address) const {
1107   CodeGen::CGBuilderTy &Builder = CGF.Builder;
1108 
1109   llvm::Value *Four8 = llvm::ConstantInt::get(CGF.Int8Ty, 4);
1110 
1111   // 0-7 are the eight integer registers;  the order is different
1112   //   on Darwin (for EH), but the range is the same.
1113   // 8 is %eip.
1114   AssignToArrayRange(Builder, Address, Four8, 0, 8);
1115 
1116   if (CGF.CGM.getTarget().getTriple().isOSDarwin()) {
1117     // 12-16 are st(0..4).  Not sure why we stop at 4.
1118     // These have size 16, which is sizeof(long double) on
1119     // platforms with 8-byte alignment for that type.
1120     llvm::Value *Sixteen8 = llvm::ConstantInt::get(CGF.Int8Ty, 16);
1121     AssignToArrayRange(Builder, Address, Sixteen8, 12, 16);
1122 
1123   } else {
1124     // 9 is %eflags, which doesn't get a size on Darwin for some
1125     // reason.
1126     Builder.CreateStore(Four8, Builder.CreateConstInBoundsGEP1_32(Address, 9));
1127 
1128     // 11-16 are st(0..5).  Not sure why we stop at 5.
1129     // These have size 12, which is sizeof(long double) on
1130     // platforms with 4-byte alignment for that type.
1131     llvm::Value *Twelve8 = llvm::ConstantInt::get(CGF.Int8Ty, 12);
1132     AssignToArrayRange(Builder, Address, Twelve8, 11, 16);
1133   }
1134 
1135   return false;
1136 }
1137 
1138 //===----------------------------------------------------------------------===//
1139 // X86-64 ABI Implementation
1140 //===----------------------------------------------------------------------===//
1141 
1142 
1143 namespace {
1144 /// X86_64ABIInfo - The X86_64 ABI information.
1145 class X86_64ABIInfo : public ABIInfo {
1146   enum Class {
1147     Integer = 0,
1148     SSE,
1149     SSEUp,
1150     X87,
1151     X87Up,
1152     ComplexX87,
1153     NoClass,
1154     Memory
1155   };
1156 
1157   /// merge - Implement the X86_64 ABI merging algorithm.
1158   ///
1159   /// Merge an accumulating classification \arg Accum with a field
1160   /// classification \arg Field.
1161   ///
1162   /// \param Accum - The accumulating classification. This should
1163   /// always be either NoClass or the result of a previous merge
1164   /// call. In addition, this should never be Memory (the caller
1165   /// should just return Memory for the aggregate).
1166   static Class merge(Class Accum, Class Field);
1167 
1168   /// postMerge - Implement the X86_64 ABI post merging algorithm.
1169   ///
1170   /// Post merger cleanup, reduces a malformed Hi and Lo pair to
1171   /// final MEMORY or SSE classes when necessary.
1172   ///
1173   /// \param AggregateSize - The size of the current aggregate in
1174   /// the classification process.
1175   ///
1176   /// \param Lo - The classification for the parts of the type
1177   /// residing in the low word of the containing object.
1178   ///
1179   /// \param Hi - The classification for the parts of the type
1180   /// residing in the higher words of the containing object.
1181   ///
1182   void postMerge(unsigned AggregateSize, Class &Lo, Class &Hi) const;
1183 
1184   /// classify - Determine the x86_64 register classes in which the
1185   /// given type T should be passed.
1186   ///
1187   /// \param Lo - The classification for the parts of the type
1188   /// residing in the low word of the containing object.
1189   ///
1190   /// \param Hi - The classification for the parts of the type
1191   /// residing in the high word of the containing object.
1192   ///
1193   /// \param OffsetBase - The bit offset of this type in the
1194   /// containing object.  Some parameters are classified different
1195   /// depending on whether they straddle an eightbyte boundary.
1196   ///
1197   /// \param isNamedArg - Whether the argument in question is a "named"
1198   /// argument, as used in AMD64-ABI 3.5.7.
1199   ///
1200   /// If a word is unused its result will be NoClass; if a type should
1201   /// be passed in Memory then at least the classification of \arg Lo
1202   /// will be Memory.
1203   ///
1204   /// The \arg Lo class will be NoClass iff the argument is ignored.
1205   ///
1206   /// If the \arg Lo class is ComplexX87, then the \arg Hi class will
1207   /// also be ComplexX87.
1208   void classify(QualType T, uint64_t OffsetBase, Class &Lo, Class &Hi,
1209                 bool isNamedArg) const;
1210 
1211   llvm::Type *GetByteVectorType(QualType Ty) const;
1212   llvm::Type *GetSSETypeAtOffset(llvm::Type *IRType,
1213                                  unsigned IROffset, QualType SourceTy,
1214                                  unsigned SourceOffset) const;
1215   llvm::Type *GetINTEGERTypeAtOffset(llvm::Type *IRType,
1216                                      unsigned IROffset, QualType SourceTy,
1217                                      unsigned SourceOffset) const;
1218 
1219   /// getIndirectResult - Give a source type \arg Ty, return a suitable result
1220   /// such that the argument will be returned in memory.
1221   ABIArgInfo getIndirectReturnResult(QualType Ty) const;
1222 
1223   /// getIndirectResult - Give a source type \arg Ty, return a suitable result
1224   /// such that the argument will be passed in memory.
1225   ///
1226   /// \param freeIntRegs - The number of free integer registers remaining
1227   /// available.
1228   ABIArgInfo getIndirectResult(QualType Ty, unsigned freeIntRegs) const;
1229 
1230   ABIArgInfo classifyReturnType(QualType RetTy) const;
1231 
1232   ABIArgInfo classifyArgumentType(QualType Ty,
1233                                   unsigned freeIntRegs,
1234                                   unsigned &neededInt,
1235                                   unsigned &neededSSE,
1236                                   bool isNamedArg) const;
1237 
1238   bool IsIllegalVectorType(QualType Ty) const;
1239 
1240   /// The 0.98 ABI revision clarified a lot of ambiguities,
1241   /// unfortunately in ways that were not always consistent with
1242   /// certain previous compilers.  In particular, platforms which
1243   /// required strict binary compatibility with older versions of GCC
1244   /// may need to exempt themselves.
1245   bool honorsRevision0_98() const {
1246     return !getTarget().getTriple().isOSDarwin();
1247   }
1248 
1249   bool HasAVX;
1250   // Some ABIs (e.g. X32 ABI and Native Client OS) use 32 bit pointers on
1251   // 64-bit hardware.
1252   bool Has64BitPointers;
1253 
1254 public:
1255   X86_64ABIInfo(CodeGen::CodeGenTypes &CGT, bool hasavx) :
1256       ABIInfo(CGT), HasAVX(hasavx),
1257       Has64BitPointers(CGT.getDataLayout().getPointerSize(0) == 8) {
1258   }
1259 
1260   bool isPassedUsingAVXType(QualType type) const {
1261     unsigned neededInt, neededSSE;
1262     // The freeIntRegs argument doesn't matter here.
1263     ABIArgInfo info = classifyArgumentType(type, 0, neededInt, neededSSE,
1264                                            /*isNamedArg*/true);
1265     if (info.isDirect()) {
1266       llvm::Type *ty = info.getCoerceToType();
1267       if (llvm::VectorType *vectorTy = dyn_cast_or_null<llvm::VectorType>(ty))
1268         return (vectorTy->getBitWidth() > 128);
1269     }
1270     return false;
1271   }
1272 
1273   void computeInfo(CGFunctionInfo &FI) const override;
1274 
1275   llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
1276                          CodeGenFunction &CGF) const override;
1277 };
1278 
1279 /// WinX86_64ABIInfo - The Windows X86_64 ABI information.
1280 class WinX86_64ABIInfo : public ABIInfo {
1281 
1282   ABIArgInfo classify(QualType Ty, bool IsReturnType) const;
1283 
1284 public:
1285   WinX86_64ABIInfo(CodeGen::CodeGenTypes &CGT) : ABIInfo(CGT) {}
1286 
1287   void computeInfo(CGFunctionInfo &FI) const override;
1288 
1289   llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
1290                          CodeGenFunction &CGF) const override;
1291 };
1292 
1293 class X86_64TargetCodeGenInfo : public TargetCodeGenInfo {
1294 public:
1295   X86_64TargetCodeGenInfo(CodeGen::CodeGenTypes &CGT, bool HasAVX)
1296       : TargetCodeGenInfo(new X86_64ABIInfo(CGT, HasAVX)) {}
1297 
1298   const X86_64ABIInfo &getABIInfo() const {
1299     return static_cast<const X86_64ABIInfo&>(TargetCodeGenInfo::getABIInfo());
1300   }
1301 
1302   int getDwarfEHStackPointer(CodeGen::CodeGenModule &CGM) const override {
1303     return 7;
1304   }
1305 
1306   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
1307                                llvm::Value *Address) const override {
1308     llvm::Value *Eight8 = llvm::ConstantInt::get(CGF.Int8Ty, 8);
1309 
1310     // 0-15 are the 16 integer registers.
1311     // 16 is %rip.
1312     AssignToArrayRange(CGF.Builder, Address, Eight8, 0, 16);
1313     return false;
1314   }
1315 
1316   llvm::Type* adjustInlineAsmType(CodeGen::CodeGenFunction &CGF,
1317                                   StringRef Constraint,
1318                                   llvm::Type* Ty) const override {
1319     return X86AdjustInlineAsmType(CGF, Constraint, Ty);
1320   }
1321 
1322   bool isNoProtoCallVariadic(const CallArgList &args,
1323                              const FunctionNoProtoType *fnType) const override {
1324     // The default CC on x86-64 sets %al to the number of SSA
1325     // registers used, and GCC sets this when calling an unprototyped
1326     // function, so we override the default behavior.  However, don't do
1327     // that when AVX types are involved: the ABI explicitly states it is
1328     // undefined, and it doesn't work in practice because of how the ABI
1329     // defines varargs anyway.
1330     if (fnType->getCallConv() == CC_C) {
1331       bool HasAVXType = false;
1332       for (CallArgList::const_iterator
1333              it = args.begin(), ie = args.end(); it != ie; ++it) {
1334         if (getABIInfo().isPassedUsingAVXType(it->Ty)) {
1335           HasAVXType = true;
1336           break;
1337         }
1338       }
1339 
1340       if (!HasAVXType)
1341         return true;
1342     }
1343 
1344     return TargetCodeGenInfo::isNoProtoCallVariadic(args, fnType);
1345   }
1346 
1347   llvm::Constant *
1348   getUBSanFunctionSignature(CodeGen::CodeGenModule &CGM) const override {
1349     unsigned Sig = (0xeb << 0) |  // jmp rel8
1350                    (0x0a << 8) |  //           .+0x0c
1351                    ('F' << 16) |
1352                    ('T' << 24);
1353     return llvm::ConstantInt::get(CGM.Int32Ty, Sig);
1354   }
1355 
1356 };
1357 
1358 static std::string qualifyWindowsLibrary(llvm::StringRef Lib) {
1359   // If the argument does not end in .lib, automatically add the suffix. This
1360   // matches the behavior of MSVC.
1361   std::string ArgStr = Lib;
1362   if (!Lib.endswith_lower(".lib"))
1363     ArgStr += ".lib";
1364   return ArgStr;
1365 }
1366 
1367 class WinX86_32TargetCodeGenInfo : public X86_32TargetCodeGenInfo {
1368 public:
1369   WinX86_32TargetCodeGenInfo(CodeGen::CodeGenTypes &CGT,
1370         bool d, bool p, bool w, unsigned RegParms)
1371     : X86_32TargetCodeGenInfo(CGT, d, p, w, RegParms) {}
1372 
1373   void getDependentLibraryOption(llvm::StringRef Lib,
1374                                  llvm::SmallString<24> &Opt) const override {
1375     Opt = "/DEFAULTLIB:";
1376     Opt += qualifyWindowsLibrary(Lib);
1377   }
1378 
1379   void getDetectMismatchOption(llvm::StringRef Name,
1380                                llvm::StringRef Value,
1381                                llvm::SmallString<32> &Opt) const override {
1382     Opt = "/FAILIFMISMATCH:\"" + Name.str() + "=" + Value.str() + "\"";
1383   }
1384 };
1385 
1386 class WinX86_64TargetCodeGenInfo : public TargetCodeGenInfo {
1387 public:
1388   WinX86_64TargetCodeGenInfo(CodeGen::CodeGenTypes &CGT)
1389     : TargetCodeGenInfo(new WinX86_64ABIInfo(CGT)) {}
1390 
1391   int getDwarfEHStackPointer(CodeGen::CodeGenModule &CGM) const override {
1392     return 7;
1393   }
1394 
1395   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
1396                                llvm::Value *Address) const override {
1397     llvm::Value *Eight8 = llvm::ConstantInt::get(CGF.Int8Ty, 8);
1398 
1399     // 0-15 are the 16 integer registers.
1400     // 16 is %rip.
1401     AssignToArrayRange(CGF.Builder, Address, Eight8, 0, 16);
1402     return false;
1403   }
1404 
1405   void getDependentLibraryOption(llvm::StringRef Lib,
1406                                  llvm::SmallString<24> &Opt) const override {
1407     Opt = "/DEFAULTLIB:";
1408     Opt += qualifyWindowsLibrary(Lib);
1409   }
1410 
1411   void getDetectMismatchOption(llvm::StringRef Name,
1412                                llvm::StringRef Value,
1413                                llvm::SmallString<32> &Opt) const override {
1414     Opt = "/FAILIFMISMATCH:\"" + Name.str() + "=" + Value.str() + "\"";
1415   }
1416 };
1417 
1418 }
1419 
1420 void X86_64ABIInfo::postMerge(unsigned AggregateSize, Class &Lo,
1421                               Class &Hi) const {
1422   // AMD64-ABI 3.2.3p2: Rule 5. Then a post merger cleanup is done:
1423   //
1424   // (a) If one of the classes is Memory, the whole argument is passed in
1425   //     memory.
1426   //
1427   // (b) If X87UP is not preceded by X87, the whole argument is passed in
1428   //     memory.
1429   //
1430   // (c) If the size of the aggregate exceeds two eightbytes and the first
1431   //     eightbyte isn't SSE or any other eightbyte isn't SSEUP, the whole
1432   //     argument is passed in memory. NOTE: This is necessary to keep the
1433   //     ABI working for processors that don't support the __m256 type.
1434   //
1435   // (d) If SSEUP is not preceded by SSE or SSEUP, it is converted to SSE.
1436   //
1437   // Some of these are enforced by the merging logic.  Others can arise
1438   // only with unions; for example:
1439   //   union { _Complex double; unsigned; }
1440   //
1441   // Note that clauses (b) and (c) were added in 0.98.
1442   //
1443   if (Hi == Memory)
1444     Lo = Memory;
1445   if (Hi == X87Up && Lo != X87 && honorsRevision0_98())
1446     Lo = Memory;
1447   if (AggregateSize > 128 && (Lo != SSE || Hi != SSEUp))
1448     Lo = Memory;
1449   if (Hi == SSEUp && Lo != SSE)
1450     Hi = SSE;
1451 }
1452 
1453 X86_64ABIInfo::Class X86_64ABIInfo::merge(Class Accum, Class Field) {
1454   // AMD64-ABI 3.2.3p2: Rule 4. Each field of an object is
1455   // classified recursively so that always two fields are
1456   // considered. The resulting class is calculated according to
1457   // the classes of the fields in the eightbyte:
1458   //
1459   // (a) If both classes are equal, this is the resulting class.
1460   //
1461   // (b) If one of the classes is NO_CLASS, the resulting class is
1462   // the other class.
1463   //
1464   // (c) If one of the classes is MEMORY, the result is the MEMORY
1465   // class.
1466   //
1467   // (d) If one of the classes is INTEGER, the result is the
1468   // INTEGER.
1469   //
1470   // (e) If one of the classes is X87, X87UP, COMPLEX_X87 class,
1471   // MEMORY is used as class.
1472   //
1473   // (f) Otherwise class SSE is used.
1474 
1475   // Accum should never be memory (we should have returned) or
1476   // ComplexX87 (because this cannot be passed in a structure).
1477   assert((Accum != Memory && Accum != ComplexX87) &&
1478          "Invalid accumulated classification during merge.");
1479   if (Accum == Field || Field == NoClass)
1480     return Accum;
1481   if (Field == Memory)
1482     return Memory;
1483   if (Accum == NoClass)
1484     return Field;
1485   if (Accum == Integer || Field == Integer)
1486     return Integer;
1487   if (Field == X87 || Field == X87Up || Field == ComplexX87 ||
1488       Accum == X87 || Accum == X87Up)
1489     return Memory;
1490   return SSE;
1491 }
1492 
1493 void X86_64ABIInfo::classify(QualType Ty, uint64_t OffsetBase,
1494                              Class &Lo, Class &Hi, bool isNamedArg) const {
1495   // FIXME: This code can be simplified by introducing a simple value class for
1496   // Class pairs with appropriate constructor methods for the various
1497   // situations.
1498 
1499   // FIXME: Some of the split computations are wrong; unaligned vectors
1500   // shouldn't be passed in registers for example, so there is no chance they
1501   // can straddle an eightbyte. Verify & simplify.
1502 
1503   Lo = Hi = NoClass;
1504 
1505   Class &Current = OffsetBase < 64 ? Lo : Hi;
1506   Current = Memory;
1507 
1508   if (const BuiltinType *BT = Ty->getAs<BuiltinType>()) {
1509     BuiltinType::Kind k = BT->getKind();
1510 
1511     if (k == BuiltinType::Void) {
1512       Current = NoClass;
1513     } else if (k == BuiltinType::Int128 || k == BuiltinType::UInt128) {
1514       Lo = Integer;
1515       Hi = Integer;
1516     } else if (k >= BuiltinType::Bool && k <= BuiltinType::LongLong) {
1517       Current = Integer;
1518     } else if ((k == BuiltinType::Float || k == BuiltinType::Double) ||
1519                (k == BuiltinType::LongDouble &&
1520                 getTarget().getTriple().isOSNaCl())) {
1521       Current = SSE;
1522     } else if (k == BuiltinType::LongDouble) {
1523       Lo = X87;
1524       Hi = X87Up;
1525     }
1526     // FIXME: _Decimal32 and _Decimal64 are SSE.
1527     // FIXME: _float128 and _Decimal128 are (SSE, SSEUp).
1528     return;
1529   }
1530 
1531   if (const EnumType *ET = Ty->getAs<EnumType>()) {
1532     // Classify the underlying integer type.
1533     classify(ET->getDecl()->getIntegerType(), OffsetBase, Lo, Hi, isNamedArg);
1534     return;
1535   }
1536 
1537   if (Ty->hasPointerRepresentation()) {
1538     Current = Integer;
1539     return;
1540   }
1541 
1542   if (Ty->isMemberPointerType()) {
1543     if (Ty->isMemberFunctionPointerType() && Has64BitPointers)
1544       Lo = Hi = Integer;
1545     else
1546       Current = Integer;
1547     return;
1548   }
1549 
1550   if (const VectorType *VT = Ty->getAs<VectorType>()) {
1551     uint64_t Size = getContext().getTypeSize(VT);
1552     if (Size == 32) {
1553       // gcc passes all <4 x char>, <2 x short>, <1 x int>, <1 x
1554       // float> as integer.
1555       Current = Integer;
1556 
1557       // If this type crosses an eightbyte boundary, it should be
1558       // split.
1559       uint64_t EB_Real = (OffsetBase) / 64;
1560       uint64_t EB_Imag = (OffsetBase + Size - 1) / 64;
1561       if (EB_Real != EB_Imag)
1562         Hi = Lo;
1563     } else if (Size == 64) {
1564       // gcc passes <1 x double> in memory. :(
1565       if (VT->getElementType()->isSpecificBuiltinType(BuiltinType::Double))
1566         return;
1567 
1568       // gcc passes <1 x long long> as INTEGER.
1569       if (VT->getElementType()->isSpecificBuiltinType(BuiltinType::LongLong) ||
1570           VT->getElementType()->isSpecificBuiltinType(BuiltinType::ULongLong) ||
1571           VT->getElementType()->isSpecificBuiltinType(BuiltinType::Long) ||
1572           VT->getElementType()->isSpecificBuiltinType(BuiltinType::ULong))
1573         Current = Integer;
1574       else
1575         Current = SSE;
1576 
1577       // If this type crosses an eightbyte boundary, it should be
1578       // split.
1579       if (OffsetBase && OffsetBase != 64)
1580         Hi = Lo;
1581     } else if (Size == 128 || (HasAVX && isNamedArg && Size == 256)) {
1582       // Arguments of 256-bits are split into four eightbyte chunks. The
1583       // least significant one belongs to class SSE and all the others to class
1584       // SSEUP. The original Lo and Hi design considers that types can't be
1585       // greater than 128-bits, so a 64-bit split in Hi and Lo makes sense.
1586       // This design isn't correct for 256-bits, but since there're no cases
1587       // where the upper parts would need to be inspected, avoid adding
1588       // complexity and just consider Hi to match the 64-256 part.
1589       //
1590       // Note that per 3.5.7 of AMD64-ABI, 256-bit args are only passed in
1591       // registers if they are "named", i.e. not part of the "..." of a
1592       // variadic function.
1593       Lo = SSE;
1594       Hi = SSEUp;
1595     }
1596     return;
1597   }
1598 
1599   if (const ComplexType *CT = Ty->getAs<ComplexType>()) {
1600     QualType ET = getContext().getCanonicalType(CT->getElementType());
1601 
1602     uint64_t Size = getContext().getTypeSize(Ty);
1603     if (ET->isIntegralOrEnumerationType()) {
1604       if (Size <= 64)
1605         Current = Integer;
1606       else if (Size <= 128)
1607         Lo = Hi = Integer;
1608     } else if (ET == getContext().FloatTy)
1609       Current = SSE;
1610     else if (ET == getContext().DoubleTy ||
1611              (ET == getContext().LongDoubleTy &&
1612               getTarget().getTriple().isOSNaCl()))
1613       Lo = Hi = SSE;
1614     else if (ET == getContext().LongDoubleTy)
1615       Current = ComplexX87;
1616 
1617     // If this complex type crosses an eightbyte boundary then it
1618     // should be split.
1619     uint64_t EB_Real = (OffsetBase) / 64;
1620     uint64_t EB_Imag = (OffsetBase + getContext().getTypeSize(ET)) / 64;
1621     if (Hi == NoClass && EB_Real != EB_Imag)
1622       Hi = Lo;
1623 
1624     return;
1625   }
1626 
1627   if (const ConstantArrayType *AT = getContext().getAsConstantArrayType(Ty)) {
1628     // Arrays are treated like structures.
1629 
1630     uint64_t Size = getContext().getTypeSize(Ty);
1631 
1632     // AMD64-ABI 3.2.3p2: Rule 1. If the size of an object is larger
1633     // than four eightbytes, ..., it has class MEMORY.
1634     if (Size > 256)
1635       return;
1636 
1637     // AMD64-ABI 3.2.3p2: Rule 1. If ..., or it contains unaligned
1638     // fields, it has class MEMORY.
1639     //
1640     // Only need to check alignment of array base.
1641     if (OffsetBase % getContext().getTypeAlign(AT->getElementType()))
1642       return;
1643 
1644     // Otherwise implement simplified merge. We could be smarter about
1645     // this, but it isn't worth it and would be harder to verify.
1646     Current = NoClass;
1647     uint64_t EltSize = getContext().getTypeSize(AT->getElementType());
1648     uint64_t ArraySize = AT->getSize().getZExtValue();
1649 
1650     // The only case a 256-bit wide vector could be used is when the array
1651     // contains a single 256-bit element. Since Lo and Hi logic isn't extended
1652     // to work for sizes wider than 128, early check and fallback to memory.
1653     if (Size > 128 && EltSize != 256)
1654       return;
1655 
1656     for (uint64_t i=0, Offset=OffsetBase; i<ArraySize; ++i, Offset += EltSize) {
1657       Class FieldLo, FieldHi;
1658       classify(AT->getElementType(), Offset, FieldLo, FieldHi, isNamedArg);
1659       Lo = merge(Lo, FieldLo);
1660       Hi = merge(Hi, FieldHi);
1661       if (Lo == Memory || Hi == Memory)
1662         break;
1663     }
1664 
1665     postMerge(Size, Lo, Hi);
1666     assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp array classification.");
1667     return;
1668   }
1669 
1670   if (const RecordType *RT = Ty->getAs<RecordType>()) {
1671     uint64_t Size = getContext().getTypeSize(Ty);
1672 
1673     // AMD64-ABI 3.2.3p2: Rule 1. If the size of an object is larger
1674     // than four eightbytes, ..., it has class MEMORY.
1675     if (Size > 256)
1676       return;
1677 
1678     // AMD64-ABI 3.2.3p2: Rule 2. If a C++ object has either a non-trivial
1679     // copy constructor or a non-trivial destructor, it is passed by invisible
1680     // reference.
1681     if (getRecordArgABI(RT, getCXXABI()))
1682       return;
1683 
1684     const RecordDecl *RD = RT->getDecl();
1685 
1686     // Assume variable sized types are passed in memory.
1687     if (RD->hasFlexibleArrayMember())
1688       return;
1689 
1690     const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
1691 
1692     // Reset Lo class, this will be recomputed.
1693     Current = NoClass;
1694 
1695     // If this is a C++ record, classify the bases first.
1696     if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
1697       for (const auto &I : CXXRD->bases()) {
1698         assert(!I.isVirtual() && !I.getType()->isDependentType() &&
1699                "Unexpected base class!");
1700         const CXXRecordDecl *Base =
1701           cast<CXXRecordDecl>(I.getType()->getAs<RecordType>()->getDecl());
1702 
1703         // Classify this field.
1704         //
1705         // AMD64-ABI 3.2.3p2: Rule 3. If the size of the aggregate exceeds a
1706         // single eightbyte, each is classified separately. Each eightbyte gets
1707         // initialized to class NO_CLASS.
1708         Class FieldLo, FieldHi;
1709         uint64_t Offset =
1710           OffsetBase + getContext().toBits(Layout.getBaseClassOffset(Base));
1711         classify(I.getType(), Offset, FieldLo, FieldHi, isNamedArg);
1712         Lo = merge(Lo, FieldLo);
1713         Hi = merge(Hi, FieldHi);
1714         if (Lo == Memory || Hi == Memory)
1715           break;
1716       }
1717     }
1718 
1719     // Classify the fields one at a time, merging the results.
1720     unsigned idx = 0;
1721     for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
1722            i != e; ++i, ++idx) {
1723       uint64_t Offset = OffsetBase + Layout.getFieldOffset(idx);
1724       bool BitField = i->isBitField();
1725 
1726       // AMD64-ABI 3.2.3p2: Rule 1. If the size of an object is larger than
1727       // four eightbytes, or it contains unaligned fields, it has class MEMORY.
1728       //
1729       // The only case a 256-bit wide vector could be used is when the struct
1730       // contains a single 256-bit element. Since Lo and Hi logic isn't extended
1731       // to work for sizes wider than 128, early check and fallback to memory.
1732       //
1733       if (Size > 128 && getContext().getTypeSize(i->getType()) != 256) {
1734         Lo = Memory;
1735         return;
1736       }
1737       // Note, skip this test for bit-fields, see below.
1738       if (!BitField && Offset % getContext().getTypeAlign(i->getType())) {
1739         Lo = Memory;
1740         return;
1741       }
1742 
1743       // Classify this field.
1744       //
1745       // AMD64-ABI 3.2.3p2: Rule 3. If the size of the aggregate
1746       // exceeds a single eightbyte, each is classified
1747       // separately. Each eightbyte gets initialized to class
1748       // NO_CLASS.
1749       Class FieldLo, FieldHi;
1750 
1751       // Bit-fields require special handling, they do not force the
1752       // structure to be passed in memory even if unaligned, and
1753       // therefore they can straddle an eightbyte.
1754       if (BitField) {
1755         // Ignore padding bit-fields.
1756         if (i->isUnnamedBitfield())
1757           continue;
1758 
1759         uint64_t Offset = OffsetBase + Layout.getFieldOffset(idx);
1760         uint64_t Size = i->getBitWidthValue(getContext());
1761 
1762         uint64_t EB_Lo = Offset / 64;
1763         uint64_t EB_Hi = (Offset + Size - 1) / 64;
1764 
1765         if (EB_Lo) {
1766           assert(EB_Hi == EB_Lo && "Invalid classification, type > 16 bytes.");
1767           FieldLo = NoClass;
1768           FieldHi = Integer;
1769         } else {
1770           FieldLo = Integer;
1771           FieldHi = EB_Hi ? Integer : NoClass;
1772         }
1773       } else
1774         classify(i->getType(), Offset, FieldLo, FieldHi, isNamedArg);
1775       Lo = merge(Lo, FieldLo);
1776       Hi = merge(Hi, FieldHi);
1777       if (Lo == Memory || Hi == Memory)
1778         break;
1779     }
1780 
1781     postMerge(Size, Lo, Hi);
1782   }
1783 }
1784 
1785 ABIArgInfo X86_64ABIInfo::getIndirectReturnResult(QualType Ty) const {
1786   // If this is a scalar LLVM value then assume LLVM will pass it in the right
1787   // place naturally.
1788   if (!isAggregateTypeForABI(Ty)) {
1789     // Treat an enum type as its underlying type.
1790     if (const EnumType *EnumTy = Ty->getAs<EnumType>())
1791       Ty = EnumTy->getDecl()->getIntegerType();
1792 
1793     return (Ty->isPromotableIntegerType() ?
1794             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
1795   }
1796 
1797   return ABIArgInfo::getIndirect(0);
1798 }
1799 
1800 bool X86_64ABIInfo::IsIllegalVectorType(QualType Ty) const {
1801   if (const VectorType *VecTy = Ty->getAs<VectorType>()) {
1802     uint64_t Size = getContext().getTypeSize(VecTy);
1803     unsigned LargestVector = HasAVX ? 256 : 128;
1804     if (Size <= 64 || Size > LargestVector)
1805       return true;
1806   }
1807 
1808   return false;
1809 }
1810 
1811 ABIArgInfo X86_64ABIInfo::getIndirectResult(QualType Ty,
1812                                             unsigned freeIntRegs) const {
1813   // If this is a scalar LLVM value then assume LLVM will pass it in the right
1814   // place naturally.
1815   //
1816   // This assumption is optimistic, as there could be free registers available
1817   // when we need to pass this argument in memory, and LLVM could try to pass
1818   // the argument in the free register. This does not seem to happen currently,
1819   // but this code would be much safer if we could mark the argument with
1820   // 'onstack'. See PR12193.
1821   if (!isAggregateTypeForABI(Ty) && !IsIllegalVectorType(Ty)) {
1822     // Treat an enum type as its underlying type.
1823     if (const EnumType *EnumTy = Ty->getAs<EnumType>())
1824       Ty = EnumTy->getDecl()->getIntegerType();
1825 
1826     return (Ty->isPromotableIntegerType() ?
1827             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
1828   }
1829 
1830   if (CGCXXABI::RecordArgABI RAA = getRecordArgABI(Ty, getCXXABI()))
1831     return ABIArgInfo::getIndirect(0, RAA == CGCXXABI::RAA_DirectInMemory);
1832 
1833   // Compute the byval alignment. We specify the alignment of the byval in all
1834   // cases so that the mid-level optimizer knows the alignment of the byval.
1835   unsigned Align = std::max(getContext().getTypeAlign(Ty) / 8, 8U);
1836 
1837   // Attempt to avoid passing indirect results using byval when possible. This
1838   // is important for good codegen.
1839   //
1840   // We do this by coercing the value into a scalar type which the backend can
1841   // handle naturally (i.e., without using byval).
1842   //
1843   // For simplicity, we currently only do this when we have exhausted all of the
1844   // free integer registers. Doing this when there are free integer registers
1845   // would require more care, as we would have to ensure that the coerced value
1846   // did not claim the unused register. That would require either reording the
1847   // arguments to the function (so that any subsequent inreg values came first),
1848   // or only doing this optimization when there were no following arguments that
1849   // might be inreg.
1850   //
1851   // We currently expect it to be rare (particularly in well written code) for
1852   // arguments to be passed on the stack when there are still free integer
1853   // registers available (this would typically imply large structs being passed
1854   // by value), so this seems like a fair tradeoff for now.
1855   //
1856   // We can revisit this if the backend grows support for 'onstack' parameter
1857   // attributes. See PR12193.
1858   if (freeIntRegs == 0) {
1859     uint64_t Size = getContext().getTypeSize(Ty);
1860 
1861     // If this type fits in an eightbyte, coerce it into the matching integral
1862     // type, which will end up on the stack (with alignment 8).
1863     if (Align == 8 && Size <= 64)
1864       return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),
1865                                                           Size));
1866   }
1867 
1868   return ABIArgInfo::getIndirect(Align);
1869 }
1870 
1871 /// GetByteVectorType - The ABI specifies that a value should be passed in an
1872 /// full vector XMM/YMM register.  Pick an LLVM IR type that will be passed as a
1873 /// vector register.
1874 llvm::Type *X86_64ABIInfo::GetByteVectorType(QualType Ty) const {
1875   llvm::Type *IRType = CGT.ConvertType(Ty);
1876 
1877   // Wrapper structs that just contain vectors are passed just like vectors,
1878   // strip them off if present.
1879   llvm::StructType *STy = dyn_cast<llvm::StructType>(IRType);
1880   while (STy && STy->getNumElements() == 1) {
1881     IRType = STy->getElementType(0);
1882     STy = dyn_cast<llvm::StructType>(IRType);
1883   }
1884 
1885   // If the preferred type is a 16-byte vector, prefer to pass it.
1886   if (llvm::VectorType *VT = dyn_cast<llvm::VectorType>(IRType)){
1887     llvm::Type *EltTy = VT->getElementType();
1888     unsigned BitWidth = VT->getBitWidth();
1889     if ((BitWidth >= 128 && BitWidth <= 256) &&
1890         (EltTy->isFloatTy() || EltTy->isDoubleTy() ||
1891          EltTy->isIntegerTy(8) || EltTy->isIntegerTy(16) ||
1892          EltTy->isIntegerTy(32) || EltTy->isIntegerTy(64) ||
1893          EltTy->isIntegerTy(128)))
1894       return VT;
1895   }
1896 
1897   return llvm::VectorType::get(llvm::Type::getDoubleTy(getVMContext()), 2);
1898 }
1899 
1900 /// BitsContainNoUserData - Return true if the specified [start,end) bit range
1901 /// is known to either be off the end of the specified type or being in
1902 /// alignment padding.  The user type specified is known to be at most 128 bits
1903 /// in size, and have passed through X86_64ABIInfo::classify with a successful
1904 /// classification that put one of the two halves in the INTEGER class.
1905 ///
1906 /// It is conservatively correct to return false.
1907 static bool BitsContainNoUserData(QualType Ty, unsigned StartBit,
1908                                   unsigned EndBit, ASTContext &Context) {
1909   // If the bytes being queried are off the end of the type, there is no user
1910   // data hiding here.  This handles analysis of builtins, vectors and other
1911   // types that don't contain interesting padding.
1912   unsigned TySize = (unsigned)Context.getTypeSize(Ty);
1913   if (TySize <= StartBit)
1914     return true;
1915 
1916   if (const ConstantArrayType *AT = Context.getAsConstantArrayType(Ty)) {
1917     unsigned EltSize = (unsigned)Context.getTypeSize(AT->getElementType());
1918     unsigned NumElts = (unsigned)AT->getSize().getZExtValue();
1919 
1920     // Check each element to see if the element overlaps with the queried range.
1921     for (unsigned i = 0; i != NumElts; ++i) {
1922       // If the element is after the span we care about, then we're done..
1923       unsigned EltOffset = i*EltSize;
1924       if (EltOffset >= EndBit) break;
1925 
1926       unsigned EltStart = EltOffset < StartBit ? StartBit-EltOffset :0;
1927       if (!BitsContainNoUserData(AT->getElementType(), EltStart,
1928                                  EndBit-EltOffset, Context))
1929         return false;
1930     }
1931     // If it overlaps no elements, then it is safe to process as padding.
1932     return true;
1933   }
1934 
1935   if (const RecordType *RT = Ty->getAs<RecordType>()) {
1936     const RecordDecl *RD = RT->getDecl();
1937     const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
1938 
1939     // If this is a C++ record, check the bases first.
1940     if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
1941       for (const auto &I : CXXRD->bases()) {
1942         assert(!I.isVirtual() && !I.getType()->isDependentType() &&
1943                "Unexpected base class!");
1944         const CXXRecordDecl *Base =
1945           cast<CXXRecordDecl>(I.getType()->getAs<RecordType>()->getDecl());
1946 
1947         // If the base is after the span we care about, ignore it.
1948         unsigned BaseOffset = Context.toBits(Layout.getBaseClassOffset(Base));
1949         if (BaseOffset >= EndBit) continue;
1950 
1951         unsigned BaseStart = BaseOffset < StartBit ? StartBit-BaseOffset :0;
1952         if (!BitsContainNoUserData(I.getType(), BaseStart,
1953                                    EndBit-BaseOffset, Context))
1954           return false;
1955       }
1956     }
1957 
1958     // Verify that no field has data that overlaps the region of interest.  Yes
1959     // this could be sped up a lot by being smarter about queried fields,
1960     // however we're only looking at structs up to 16 bytes, so we don't care
1961     // much.
1962     unsigned idx = 0;
1963     for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
1964          i != e; ++i, ++idx) {
1965       unsigned FieldOffset = (unsigned)Layout.getFieldOffset(idx);
1966 
1967       // If we found a field after the region we care about, then we're done.
1968       if (FieldOffset >= EndBit) break;
1969 
1970       unsigned FieldStart = FieldOffset < StartBit ? StartBit-FieldOffset :0;
1971       if (!BitsContainNoUserData(i->getType(), FieldStart, EndBit-FieldOffset,
1972                                  Context))
1973         return false;
1974     }
1975 
1976     // If nothing in this record overlapped the area of interest, then we're
1977     // clean.
1978     return true;
1979   }
1980 
1981   return false;
1982 }
1983 
1984 /// ContainsFloatAtOffset - Return true if the specified LLVM IR type has a
1985 /// float member at the specified offset.  For example, {int,{float}} has a
1986 /// float at offset 4.  It is conservatively correct for this routine to return
1987 /// false.
1988 static bool ContainsFloatAtOffset(llvm::Type *IRType, unsigned IROffset,
1989                                   const llvm::DataLayout &TD) {
1990   // Base case if we find a float.
1991   if (IROffset == 0 && IRType->isFloatTy())
1992     return true;
1993 
1994   // If this is a struct, recurse into the field at the specified offset.
1995   if (llvm::StructType *STy = dyn_cast<llvm::StructType>(IRType)) {
1996     const llvm::StructLayout *SL = TD.getStructLayout(STy);
1997     unsigned Elt = SL->getElementContainingOffset(IROffset);
1998     IROffset -= SL->getElementOffset(Elt);
1999     return ContainsFloatAtOffset(STy->getElementType(Elt), IROffset, TD);
2000   }
2001 
2002   // If this is an array, recurse into the field at the specified offset.
2003   if (llvm::ArrayType *ATy = dyn_cast<llvm::ArrayType>(IRType)) {
2004     llvm::Type *EltTy = ATy->getElementType();
2005     unsigned EltSize = TD.getTypeAllocSize(EltTy);
2006     IROffset -= IROffset/EltSize*EltSize;
2007     return ContainsFloatAtOffset(EltTy, IROffset, TD);
2008   }
2009 
2010   return false;
2011 }
2012 
2013 
2014 /// GetSSETypeAtOffset - Return a type that will be passed by the backend in the
2015 /// low 8 bytes of an XMM register, corresponding to the SSE class.
2016 llvm::Type *X86_64ABIInfo::
2017 GetSSETypeAtOffset(llvm::Type *IRType, unsigned IROffset,
2018                    QualType SourceTy, unsigned SourceOffset) const {
2019   // The only three choices we have are either double, <2 x float>, or float. We
2020   // pass as float if the last 4 bytes is just padding.  This happens for
2021   // structs that contain 3 floats.
2022   if (BitsContainNoUserData(SourceTy, SourceOffset*8+32,
2023                             SourceOffset*8+64, getContext()))
2024     return llvm::Type::getFloatTy(getVMContext());
2025 
2026   // We want to pass as <2 x float> if the LLVM IR type contains a float at
2027   // offset+0 and offset+4.  Walk the LLVM IR type to find out if this is the
2028   // case.
2029   if (ContainsFloatAtOffset(IRType, IROffset, getDataLayout()) &&
2030       ContainsFloatAtOffset(IRType, IROffset+4, getDataLayout()))
2031     return llvm::VectorType::get(llvm::Type::getFloatTy(getVMContext()), 2);
2032 
2033   return llvm::Type::getDoubleTy(getVMContext());
2034 }
2035 
2036 
2037 /// GetINTEGERTypeAtOffset - The ABI specifies that a value should be passed in
2038 /// an 8-byte GPR.  This means that we either have a scalar or we are talking
2039 /// about the high or low part of an up-to-16-byte struct.  This routine picks
2040 /// the best LLVM IR type to represent this, which may be i64 or may be anything
2041 /// else that the backend will pass in a GPR that works better (e.g. i8, %foo*,
2042 /// etc).
2043 ///
2044 /// PrefType is an LLVM IR type that corresponds to (part of) the IR type for
2045 /// the source type.  IROffset is an offset in bytes into the LLVM IR type that
2046 /// the 8-byte value references.  PrefType may be null.
2047 ///
2048 /// SourceTy is the source level type for the entire argument.  SourceOffset is
2049 /// an offset into this that we're processing (which is always either 0 or 8).
2050 ///
2051 llvm::Type *X86_64ABIInfo::
2052 GetINTEGERTypeAtOffset(llvm::Type *IRType, unsigned IROffset,
2053                        QualType SourceTy, unsigned SourceOffset) const {
2054   // If we're dealing with an un-offset LLVM IR type, then it means that we're
2055   // returning an 8-byte unit starting with it.  See if we can safely use it.
2056   if (IROffset == 0) {
2057     // Pointers and int64's always fill the 8-byte unit.
2058     if ((isa<llvm::PointerType>(IRType) && Has64BitPointers) ||
2059         IRType->isIntegerTy(64))
2060       return IRType;
2061 
2062     // If we have a 1/2/4-byte integer, we can use it only if the rest of the
2063     // goodness in the source type is just tail padding.  This is allowed to
2064     // kick in for struct {double,int} on the int, but not on
2065     // struct{double,int,int} because we wouldn't return the second int.  We
2066     // have to do this analysis on the source type because we can't depend on
2067     // unions being lowered a specific way etc.
2068     if (IRType->isIntegerTy(8) || IRType->isIntegerTy(16) ||
2069         IRType->isIntegerTy(32) ||
2070         (isa<llvm::PointerType>(IRType) && !Has64BitPointers)) {
2071       unsigned BitWidth = isa<llvm::PointerType>(IRType) ? 32 :
2072           cast<llvm::IntegerType>(IRType)->getBitWidth();
2073 
2074       if (BitsContainNoUserData(SourceTy, SourceOffset*8+BitWidth,
2075                                 SourceOffset*8+64, getContext()))
2076         return IRType;
2077     }
2078   }
2079 
2080   if (llvm::StructType *STy = dyn_cast<llvm::StructType>(IRType)) {
2081     // If this is a struct, recurse into the field at the specified offset.
2082     const llvm::StructLayout *SL = getDataLayout().getStructLayout(STy);
2083     if (IROffset < SL->getSizeInBytes()) {
2084       unsigned FieldIdx = SL->getElementContainingOffset(IROffset);
2085       IROffset -= SL->getElementOffset(FieldIdx);
2086 
2087       return GetINTEGERTypeAtOffset(STy->getElementType(FieldIdx), IROffset,
2088                                     SourceTy, SourceOffset);
2089     }
2090   }
2091 
2092   if (llvm::ArrayType *ATy = dyn_cast<llvm::ArrayType>(IRType)) {
2093     llvm::Type *EltTy = ATy->getElementType();
2094     unsigned EltSize = getDataLayout().getTypeAllocSize(EltTy);
2095     unsigned EltOffset = IROffset/EltSize*EltSize;
2096     return GetINTEGERTypeAtOffset(EltTy, IROffset-EltOffset, SourceTy,
2097                                   SourceOffset);
2098   }
2099 
2100   // Okay, we don't have any better idea of what to pass, so we pass this in an
2101   // integer register that isn't too big to fit the rest of the struct.
2102   unsigned TySizeInBytes =
2103     (unsigned)getContext().getTypeSizeInChars(SourceTy).getQuantity();
2104 
2105   assert(TySizeInBytes != SourceOffset && "Empty field?");
2106 
2107   // It is always safe to classify this as an integer type up to i64 that
2108   // isn't larger than the structure.
2109   return llvm::IntegerType::get(getVMContext(),
2110                                 std::min(TySizeInBytes-SourceOffset, 8U)*8);
2111 }
2112 
2113 
2114 /// GetX86_64ByValArgumentPair - Given a high and low type that can ideally
2115 /// be used as elements of a two register pair to pass or return, return a
2116 /// first class aggregate to represent them.  For example, if the low part of
2117 /// a by-value argument should be passed as i32* and the high part as float,
2118 /// return {i32*, float}.
2119 static llvm::Type *
2120 GetX86_64ByValArgumentPair(llvm::Type *Lo, llvm::Type *Hi,
2121                            const llvm::DataLayout &TD) {
2122   // In order to correctly satisfy the ABI, we need to the high part to start
2123   // at offset 8.  If the high and low parts we inferred are both 4-byte types
2124   // (e.g. i32 and i32) then the resultant struct type ({i32,i32}) won't have
2125   // the second element at offset 8.  Check for this:
2126   unsigned LoSize = (unsigned)TD.getTypeAllocSize(Lo);
2127   unsigned HiAlign = TD.getABITypeAlignment(Hi);
2128   unsigned HiStart = llvm::DataLayout::RoundUpAlignment(LoSize, HiAlign);
2129   assert(HiStart != 0 && HiStart <= 8 && "Invalid x86-64 argument pair!");
2130 
2131   // To handle this, we have to increase the size of the low part so that the
2132   // second element will start at an 8 byte offset.  We can't increase the size
2133   // of the second element because it might make us access off the end of the
2134   // struct.
2135   if (HiStart != 8) {
2136     // There are only two sorts of types the ABI generation code can produce for
2137     // the low part of a pair that aren't 8 bytes in size: float or i8/i16/i32.
2138     // Promote these to a larger type.
2139     if (Lo->isFloatTy())
2140       Lo = llvm::Type::getDoubleTy(Lo->getContext());
2141     else {
2142       assert(Lo->isIntegerTy() && "Invalid/unknown lo type");
2143       Lo = llvm::Type::getInt64Ty(Lo->getContext());
2144     }
2145   }
2146 
2147   llvm::StructType *Result = llvm::StructType::get(Lo, Hi, NULL);
2148 
2149 
2150   // Verify that the second element is at an 8-byte offset.
2151   assert(TD.getStructLayout(Result)->getElementOffset(1) == 8 &&
2152          "Invalid x86-64 argument pair!");
2153   return Result;
2154 }
2155 
2156 ABIArgInfo X86_64ABIInfo::
2157 classifyReturnType(QualType RetTy) const {
2158   // AMD64-ABI 3.2.3p4: Rule 1. Classify the return type with the
2159   // classification algorithm.
2160   X86_64ABIInfo::Class Lo, Hi;
2161   classify(RetTy, 0, Lo, Hi, /*isNamedArg*/ true);
2162 
2163   // Check some invariants.
2164   assert((Hi != Memory || Lo == Memory) && "Invalid memory classification.");
2165   assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp classification.");
2166 
2167   llvm::Type *ResType = 0;
2168   switch (Lo) {
2169   case NoClass:
2170     if (Hi == NoClass)
2171       return ABIArgInfo::getIgnore();
2172     // If the low part is just padding, it takes no register, leave ResType
2173     // null.
2174     assert((Hi == SSE || Hi == Integer || Hi == X87Up) &&
2175            "Unknown missing lo part");
2176     break;
2177 
2178   case SSEUp:
2179   case X87Up:
2180     llvm_unreachable("Invalid classification for lo word.");
2181 
2182     // AMD64-ABI 3.2.3p4: Rule 2. Types of class memory are returned via
2183     // hidden argument.
2184   case Memory:
2185     return getIndirectReturnResult(RetTy);
2186 
2187     // AMD64-ABI 3.2.3p4: Rule 3. If the class is INTEGER, the next
2188     // available register of the sequence %rax, %rdx is used.
2189   case Integer:
2190     ResType = GetINTEGERTypeAtOffset(CGT.ConvertType(RetTy), 0, RetTy, 0);
2191 
2192     // If we have a sign or zero extended integer, make sure to return Extend
2193     // so that the parameter gets the right LLVM IR attributes.
2194     if (Hi == NoClass && isa<llvm::IntegerType>(ResType)) {
2195       // Treat an enum type as its underlying type.
2196       if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
2197         RetTy = EnumTy->getDecl()->getIntegerType();
2198 
2199       if (RetTy->isIntegralOrEnumerationType() &&
2200           RetTy->isPromotableIntegerType())
2201         return ABIArgInfo::getExtend();
2202     }
2203     break;
2204 
2205     // AMD64-ABI 3.2.3p4: Rule 4. If the class is SSE, the next
2206     // available SSE register of the sequence %xmm0, %xmm1 is used.
2207   case SSE:
2208     ResType = GetSSETypeAtOffset(CGT.ConvertType(RetTy), 0, RetTy, 0);
2209     break;
2210 
2211     // AMD64-ABI 3.2.3p4: Rule 6. If the class is X87, the value is
2212     // returned on the X87 stack in %st0 as 80-bit x87 number.
2213   case X87:
2214     ResType = llvm::Type::getX86_FP80Ty(getVMContext());
2215     break;
2216 
2217     // AMD64-ABI 3.2.3p4: Rule 8. If the class is COMPLEX_X87, the real
2218     // part of the value is returned in %st0 and the imaginary part in
2219     // %st1.
2220   case ComplexX87:
2221     assert(Hi == ComplexX87 && "Unexpected ComplexX87 classification.");
2222     ResType = llvm::StructType::get(llvm::Type::getX86_FP80Ty(getVMContext()),
2223                                     llvm::Type::getX86_FP80Ty(getVMContext()),
2224                                     NULL);
2225     break;
2226   }
2227 
2228   llvm::Type *HighPart = 0;
2229   switch (Hi) {
2230     // Memory was handled previously and X87 should
2231     // never occur as a hi class.
2232   case Memory:
2233   case X87:
2234     llvm_unreachable("Invalid classification for hi word.");
2235 
2236   case ComplexX87: // Previously handled.
2237   case NoClass:
2238     break;
2239 
2240   case Integer:
2241     HighPart = GetINTEGERTypeAtOffset(CGT.ConvertType(RetTy), 8, RetTy, 8);
2242     if (Lo == NoClass)  // Return HighPart at offset 8 in memory.
2243       return ABIArgInfo::getDirect(HighPart, 8);
2244     break;
2245   case SSE:
2246     HighPart = GetSSETypeAtOffset(CGT.ConvertType(RetTy), 8, RetTy, 8);
2247     if (Lo == NoClass)  // Return HighPart at offset 8 in memory.
2248       return ABIArgInfo::getDirect(HighPart, 8);
2249     break;
2250 
2251     // AMD64-ABI 3.2.3p4: Rule 5. If the class is SSEUP, the eightbyte
2252     // is passed in the next available eightbyte chunk if the last used
2253     // vector register.
2254     //
2255     // SSEUP should always be preceded by SSE, just widen.
2256   case SSEUp:
2257     assert(Lo == SSE && "Unexpected SSEUp classification.");
2258     ResType = GetByteVectorType(RetTy);
2259     break;
2260 
2261     // AMD64-ABI 3.2.3p4: Rule 7. If the class is X87UP, the value is
2262     // returned together with the previous X87 value in %st0.
2263   case X87Up:
2264     // If X87Up is preceded by X87, we don't need to do
2265     // anything. However, in some cases with unions it may not be
2266     // preceded by X87. In such situations we follow gcc and pass the
2267     // extra bits in an SSE reg.
2268     if (Lo != X87) {
2269       HighPart = GetSSETypeAtOffset(CGT.ConvertType(RetTy), 8, RetTy, 8);
2270       if (Lo == NoClass)  // Return HighPart at offset 8 in memory.
2271         return ABIArgInfo::getDirect(HighPart, 8);
2272     }
2273     break;
2274   }
2275 
2276   // If a high part was specified, merge it together with the low part.  It is
2277   // known to pass in the high eightbyte of the result.  We do this by forming a
2278   // first class struct aggregate with the high and low part: {low, high}
2279   if (HighPart)
2280     ResType = GetX86_64ByValArgumentPair(ResType, HighPart, getDataLayout());
2281 
2282   return ABIArgInfo::getDirect(ResType);
2283 }
2284 
2285 ABIArgInfo X86_64ABIInfo::classifyArgumentType(
2286   QualType Ty, unsigned freeIntRegs, unsigned &neededInt, unsigned &neededSSE,
2287   bool isNamedArg)
2288   const
2289 {
2290   X86_64ABIInfo::Class Lo, Hi;
2291   classify(Ty, 0, Lo, Hi, isNamedArg);
2292 
2293   // Check some invariants.
2294   // FIXME: Enforce these by construction.
2295   assert((Hi != Memory || Lo == Memory) && "Invalid memory classification.");
2296   assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp classification.");
2297 
2298   neededInt = 0;
2299   neededSSE = 0;
2300   llvm::Type *ResType = 0;
2301   switch (Lo) {
2302   case NoClass:
2303     if (Hi == NoClass)
2304       return ABIArgInfo::getIgnore();
2305     // If the low part is just padding, it takes no register, leave ResType
2306     // null.
2307     assert((Hi == SSE || Hi == Integer || Hi == X87Up) &&
2308            "Unknown missing lo part");
2309     break;
2310 
2311     // AMD64-ABI 3.2.3p3: Rule 1. If the class is MEMORY, pass the argument
2312     // on the stack.
2313   case Memory:
2314 
2315     // AMD64-ABI 3.2.3p3: Rule 5. If the class is X87, X87UP or
2316     // COMPLEX_X87, it is passed in memory.
2317   case X87:
2318   case ComplexX87:
2319     if (getRecordArgABI(Ty, getCXXABI()) == CGCXXABI::RAA_Indirect)
2320       ++neededInt;
2321     return getIndirectResult(Ty, freeIntRegs);
2322 
2323   case SSEUp:
2324   case X87Up:
2325     llvm_unreachable("Invalid classification for lo word.");
2326 
2327     // AMD64-ABI 3.2.3p3: Rule 2. If the class is INTEGER, the next
2328     // available register of the sequence %rdi, %rsi, %rdx, %rcx, %r8
2329     // and %r9 is used.
2330   case Integer:
2331     ++neededInt;
2332 
2333     // Pick an 8-byte type based on the preferred type.
2334     ResType = GetINTEGERTypeAtOffset(CGT.ConvertType(Ty), 0, Ty, 0);
2335 
2336     // If we have a sign or zero extended integer, make sure to return Extend
2337     // so that the parameter gets the right LLVM IR attributes.
2338     if (Hi == NoClass && isa<llvm::IntegerType>(ResType)) {
2339       // Treat an enum type as its underlying type.
2340       if (const EnumType *EnumTy = Ty->getAs<EnumType>())
2341         Ty = EnumTy->getDecl()->getIntegerType();
2342 
2343       if (Ty->isIntegralOrEnumerationType() &&
2344           Ty->isPromotableIntegerType())
2345         return ABIArgInfo::getExtend();
2346     }
2347 
2348     break;
2349 
2350     // AMD64-ABI 3.2.3p3: Rule 3. If the class is SSE, the next
2351     // available SSE register is used, the registers are taken in the
2352     // order from %xmm0 to %xmm7.
2353   case SSE: {
2354     llvm::Type *IRType = CGT.ConvertType(Ty);
2355     ResType = GetSSETypeAtOffset(IRType, 0, Ty, 0);
2356     ++neededSSE;
2357     break;
2358   }
2359   }
2360 
2361   llvm::Type *HighPart = 0;
2362   switch (Hi) {
2363     // Memory was handled previously, ComplexX87 and X87 should
2364     // never occur as hi classes, and X87Up must be preceded by X87,
2365     // which is passed in memory.
2366   case Memory:
2367   case X87:
2368   case ComplexX87:
2369     llvm_unreachable("Invalid classification for hi word.");
2370 
2371   case NoClass: break;
2372 
2373   case Integer:
2374     ++neededInt;
2375     // Pick an 8-byte type based on the preferred type.
2376     HighPart = GetINTEGERTypeAtOffset(CGT.ConvertType(Ty), 8, Ty, 8);
2377 
2378     if (Lo == NoClass)  // Pass HighPart at offset 8 in memory.
2379       return ABIArgInfo::getDirect(HighPart, 8);
2380     break;
2381 
2382     // X87Up generally doesn't occur here (long double is passed in
2383     // memory), except in situations involving unions.
2384   case X87Up:
2385   case SSE:
2386     HighPart = GetSSETypeAtOffset(CGT.ConvertType(Ty), 8, Ty, 8);
2387 
2388     if (Lo == NoClass)  // Pass HighPart at offset 8 in memory.
2389       return ABIArgInfo::getDirect(HighPart, 8);
2390 
2391     ++neededSSE;
2392     break;
2393 
2394     // AMD64-ABI 3.2.3p3: Rule 4. If the class is SSEUP, the
2395     // eightbyte is passed in the upper half of the last used SSE
2396     // register.  This only happens when 128-bit vectors are passed.
2397   case SSEUp:
2398     assert(Lo == SSE && "Unexpected SSEUp classification");
2399     ResType = GetByteVectorType(Ty);
2400     break;
2401   }
2402 
2403   // If a high part was specified, merge it together with the low part.  It is
2404   // known to pass in the high eightbyte of the result.  We do this by forming a
2405   // first class struct aggregate with the high and low part: {low, high}
2406   if (HighPart)
2407     ResType = GetX86_64ByValArgumentPair(ResType, HighPart, getDataLayout());
2408 
2409   return ABIArgInfo::getDirect(ResType);
2410 }
2411 
2412 void X86_64ABIInfo::computeInfo(CGFunctionInfo &FI) const {
2413 
2414   if (!getCXXABI().classifyReturnType(FI))
2415     FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
2416 
2417   // Keep track of the number of assigned registers.
2418   unsigned freeIntRegs = 6, freeSSERegs = 8;
2419 
2420   // If the return value is indirect, then the hidden argument is consuming one
2421   // integer register.
2422   if (FI.getReturnInfo().isIndirect())
2423     --freeIntRegs;
2424 
2425   bool isVariadic = FI.isVariadic();
2426   unsigned numRequiredArgs = 0;
2427   if (isVariadic)
2428     numRequiredArgs = FI.getRequiredArgs().getNumRequiredArgs();
2429 
2430   // AMD64-ABI 3.2.3p3: Once arguments are classified, the registers
2431   // get assigned (in left-to-right order) for passing as follows...
2432   for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
2433        it != ie; ++it) {
2434     bool isNamedArg = true;
2435     if (isVariadic)
2436       isNamedArg = (it - FI.arg_begin()) <
2437                     static_cast<signed>(numRequiredArgs);
2438 
2439     unsigned neededInt, neededSSE;
2440     it->info = classifyArgumentType(it->type, freeIntRegs, neededInt,
2441                                     neededSSE, isNamedArg);
2442 
2443     // AMD64-ABI 3.2.3p3: If there are no registers available for any
2444     // eightbyte of an argument, the whole argument is passed on the
2445     // stack. If registers have already been assigned for some
2446     // eightbytes of such an argument, the assignments get reverted.
2447     if (freeIntRegs >= neededInt && freeSSERegs >= neededSSE) {
2448       freeIntRegs -= neededInt;
2449       freeSSERegs -= neededSSE;
2450     } else {
2451       it->info = getIndirectResult(it->type, freeIntRegs);
2452     }
2453   }
2454 }
2455 
2456 static llvm::Value *EmitVAArgFromMemory(llvm::Value *VAListAddr,
2457                                         QualType Ty,
2458                                         CodeGenFunction &CGF) {
2459   llvm::Value *overflow_arg_area_p =
2460     CGF.Builder.CreateStructGEP(VAListAddr, 2, "overflow_arg_area_p");
2461   llvm::Value *overflow_arg_area =
2462     CGF.Builder.CreateLoad(overflow_arg_area_p, "overflow_arg_area");
2463 
2464   // AMD64-ABI 3.5.7p5: Step 7. Align l->overflow_arg_area upwards to a 16
2465   // byte boundary if alignment needed by type exceeds 8 byte boundary.
2466   // It isn't stated explicitly in the standard, but in practice we use
2467   // alignment greater than 16 where necessary.
2468   uint64_t Align = CGF.getContext().getTypeAlign(Ty) / 8;
2469   if (Align > 8) {
2470     // overflow_arg_area = (overflow_arg_area + align - 1) & -align;
2471     llvm::Value *Offset =
2472       llvm::ConstantInt::get(CGF.Int64Ty, Align - 1);
2473     overflow_arg_area = CGF.Builder.CreateGEP(overflow_arg_area, Offset);
2474     llvm::Value *AsInt = CGF.Builder.CreatePtrToInt(overflow_arg_area,
2475                                                     CGF.Int64Ty);
2476     llvm::Value *Mask = llvm::ConstantInt::get(CGF.Int64Ty, -(uint64_t)Align);
2477     overflow_arg_area =
2478       CGF.Builder.CreateIntToPtr(CGF.Builder.CreateAnd(AsInt, Mask),
2479                                  overflow_arg_area->getType(),
2480                                  "overflow_arg_area.align");
2481   }
2482 
2483   // AMD64-ABI 3.5.7p5: Step 8. Fetch type from l->overflow_arg_area.
2484   llvm::Type *LTy = CGF.ConvertTypeForMem(Ty);
2485   llvm::Value *Res =
2486     CGF.Builder.CreateBitCast(overflow_arg_area,
2487                               llvm::PointerType::getUnqual(LTy));
2488 
2489   // AMD64-ABI 3.5.7p5: Step 9. Set l->overflow_arg_area to:
2490   // l->overflow_arg_area + sizeof(type).
2491   // AMD64-ABI 3.5.7p5: Step 10. Align l->overflow_arg_area upwards to
2492   // an 8 byte boundary.
2493 
2494   uint64_t SizeInBytes = (CGF.getContext().getTypeSize(Ty) + 7) / 8;
2495   llvm::Value *Offset =
2496       llvm::ConstantInt::get(CGF.Int32Ty, (SizeInBytes + 7)  & ~7);
2497   overflow_arg_area = CGF.Builder.CreateGEP(overflow_arg_area, Offset,
2498                                             "overflow_arg_area.next");
2499   CGF.Builder.CreateStore(overflow_arg_area, overflow_arg_area_p);
2500 
2501   // AMD64-ABI 3.5.7p5: Step 11. Return the fetched type.
2502   return Res;
2503 }
2504 
2505 llvm::Value *X86_64ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
2506                                       CodeGenFunction &CGF) const {
2507   // Assume that va_list type is correct; should be pointer to LLVM type:
2508   // struct {
2509   //   i32 gp_offset;
2510   //   i32 fp_offset;
2511   //   i8* overflow_arg_area;
2512   //   i8* reg_save_area;
2513   // };
2514   unsigned neededInt, neededSSE;
2515 
2516   Ty = CGF.getContext().getCanonicalType(Ty);
2517   ABIArgInfo AI = classifyArgumentType(Ty, 0, neededInt, neededSSE,
2518                                        /*isNamedArg*/false);
2519 
2520   // AMD64-ABI 3.5.7p5: Step 1. Determine whether type may be passed
2521   // in the registers. If not go to step 7.
2522   if (!neededInt && !neededSSE)
2523     return EmitVAArgFromMemory(VAListAddr, Ty, CGF);
2524 
2525   // AMD64-ABI 3.5.7p5: Step 2. Compute num_gp to hold the number of
2526   // general purpose registers needed to pass type and num_fp to hold
2527   // the number of floating point registers needed.
2528 
2529   // AMD64-ABI 3.5.7p5: Step 3. Verify whether arguments fit into
2530   // registers. In the case: l->gp_offset > 48 - num_gp * 8 or
2531   // l->fp_offset > 304 - num_fp * 16 go to step 7.
2532   //
2533   // NOTE: 304 is a typo, there are (6 * 8 + 8 * 16) = 176 bytes of
2534   // register save space).
2535 
2536   llvm::Value *InRegs = 0;
2537   llvm::Value *gp_offset_p = 0, *gp_offset = 0;
2538   llvm::Value *fp_offset_p = 0, *fp_offset = 0;
2539   if (neededInt) {
2540     gp_offset_p = CGF.Builder.CreateStructGEP(VAListAddr, 0, "gp_offset_p");
2541     gp_offset = CGF.Builder.CreateLoad(gp_offset_p, "gp_offset");
2542     InRegs = llvm::ConstantInt::get(CGF.Int32Ty, 48 - neededInt * 8);
2543     InRegs = CGF.Builder.CreateICmpULE(gp_offset, InRegs, "fits_in_gp");
2544   }
2545 
2546   if (neededSSE) {
2547     fp_offset_p = CGF.Builder.CreateStructGEP(VAListAddr, 1, "fp_offset_p");
2548     fp_offset = CGF.Builder.CreateLoad(fp_offset_p, "fp_offset");
2549     llvm::Value *FitsInFP =
2550       llvm::ConstantInt::get(CGF.Int32Ty, 176 - neededSSE * 16);
2551     FitsInFP = CGF.Builder.CreateICmpULE(fp_offset, FitsInFP, "fits_in_fp");
2552     InRegs = InRegs ? CGF.Builder.CreateAnd(InRegs, FitsInFP) : FitsInFP;
2553   }
2554 
2555   llvm::BasicBlock *InRegBlock = CGF.createBasicBlock("vaarg.in_reg");
2556   llvm::BasicBlock *InMemBlock = CGF.createBasicBlock("vaarg.in_mem");
2557   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("vaarg.end");
2558   CGF.Builder.CreateCondBr(InRegs, InRegBlock, InMemBlock);
2559 
2560   // Emit code to load the value if it was passed in registers.
2561 
2562   CGF.EmitBlock(InRegBlock);
2563 
2564   // AMD64-ABI 3.5.7p5: Step 4. Fetch type from l->reg_save_area with
2565   // an offset of l->gp_offset and/or l->fp_offset. This may require
2566   // copying to a temporary location in case the parameter is passed
2567   // in different register classes or requires an alignment greater
2568   // than 8 for general purpose registers and 16 for XMM registers.
2569   //
2570   // FIXME: This really results in shameful code when we end up needing to
2571   // collect arguments from different places; often what should result in a
2572   // simple assembling of a structure from scattered addresses has many more
2573   // loads than necessary. Can we clean this up?
2574   llvm::Type *LTy = CGF.ConvertTypeForMem(Ty);
2575   llvm::Value *RegAddr =
2576     CGF.Builder.CreateLoad(CGF.Builder.CreateStructGEP(VAListAddr, 3),
2577                            "reg_save_area");
2578   if (neededInt && neededSSE) {
2579     // FIXME: Cleanup.
2580     assert(AI.isDirect() && "Unexpected ABI info for mixed regs");
2581     llvm::StructType *ST = cast<llvm::StructType>(AI.getCoerceToType());
2582     llvm::Value *Tmp = CGF.CreateMemTemp(Ty);
2583     Tmp = CGF.Builder.CreateBitCast(Tmp, ST->getPointerTo());
2584     assert(ST->getNumElements() == 2 && "Unexpected ABI info for mixed regs");
2585     llvm::Type *TyLo = ST->getElementType(0);
2586     llvm::Type *TyHi = ST->getElementType(1);
2587     assert((TyLo->isFPOrFPVectorTy() ^ TyHi->isFPOrFPVectorTy()) &&
2588            "Unexpected ABI info for mixed regs");
2589     llvm::Type *PTyLo = llvm::PointerType::getUnqual(TyLo);
2590     llvm::Type *PTyHi = llvm::PointerType::getUnqual(TyHi);
2591     llvm::Value *GPAddr = CGF.Builder.CreateGEP(RegAddr, gp_offset);
2592     llvm::Value *FPAddr = CGF.Builder.CreateGEP(RegAddr, fp_offset);
2593     llvm::Value *RegLoAddr = TyLo->isFloatingPointTy() ? FPAddr : GPAddr;
2594     llvm::Value *RegHiAddr = TyLo->isFloatingPointTy() ? GPAddr : FPAddr;
2595     llvm::Value *V =
2596       CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegLoAddr, PTyLo));
2597     CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 0));
2598     V = CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegHiAddr, PTyHi));
2599     CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 1));
2600 
2601     RegAddr = CGF.Builder.CreateBitCast(Tmp,
2602                                         llvm::PointerType::getUnqual(LTy));
2603   } else if (neededInt) {
2604     RegAddr = CGF.Builder.CreateGEP(RegAddr, gp_offset);
2605     RegAddr = CGF.Builder.CreateBitCast(RegAddr,
2606                                         llvm::PointerType::getUnqual(LTy));
2607 
2608     // Copy to a temporary if necessary to ensure the appropriate alignment.
2609     std::pair<CharUnits, CharUnits> SizeAlign =
2610         CGF.getContext().getTypeInfoInChars(Ty);
2611     uint64_t TySize = SizeAlign.first.getQuantity();
2612     unsigned TyAlign = SizeAlign.second.getQuantity();
2613     if (TyAlign > 8) {
2614       llvm::Value *Tmp = CGF.CreateMemTemp(Ty);
2615       CGF.Builder.CreateMemCpy(Tmp, RegAddr, TySize, 8, false);
2616       RegAddr = Tmp;
2617     }
2618   } else if (neededSSE == 1) {
2619     RegAddr = CGF.Builder.CreateGEP(RegAddr, fp_offset);
2620     RegAddr = CGF.Builder.CreateBitCast(RegAddr,
2621                                         llvm::PointerType::getUnqual(LTy));
2622   } else {
2623     assert(neededSSE == 2 && "Invalid number of needed registers!");
2624     // SSE registers are spaced 16 bytes apart in the register save
2625     // area, we need to collect the two eightbytes together.
2626     llvm::Value *RegAddrLo = CGF.Builder.CreateGEP(RegAddr, fp_offset);
2627     llvm::Value *RegAddrHi = CGF.Builder.CreateConstGEP1_32(RegAddrLo, 16);
2628     llvm::Type *DoubleTy = CGF.DoubleTy;
2629     llvm::Type *DblPtrTy =
2630       llvm::PointerType::getUnqual(DoubleTy);
2631     llvm::StructType *ST = llvm::StructType::get(DoubleTy, DoubleTy, NULL);
2632     llvm::Value *V, *Tmp = CGF.CreateMemTemp(Ty);
2633     Tmp = CGF.Builder.CreateBitCast(Tmp, ST->getPointerTo());
2634     V = CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegAddrLo,
2635                                                          DblPtrTy));
2636     CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 0));
2637     V = CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegAddrHi,
2638                                                          DblPtrTy));
2639     CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 1));
2640     RegAddr = CGF.Builder.CreateBitCast(Tmp,
2641                                         llvm::PointerType::getUnqual(LTy));
2642   }
2643 
2644   // AMD64-ABI 3.5.7p5: Step 5. Set:
2645   // l->gp_offset = l->gp_offset + num_gp * 8
2646   // l->fp_offset = l->fp_offset + num_fp * 16.
2647   if (neededInt) {
2648     llvm::Value *Offset = llvm::ConstantInt::get(CGF.Int32Ty, neededInt * 8);
2649     CGF.Builder.CreateStore(CGF.Builder.CreateAdd(gp_offset, Offset),
2650                             gp_offset_p);
2651   }
2652   if (neededSSE) {
2653     llvm::Value *Offset = llvm::ConstantInt::get(CGF.Int32Ty, neededSSE * 16);
2654     CGF.Builder.CreateStore(CGF.Builder.CreateAdd(fp_offset, Offset),
2655                             fp_offset_p);
2656   }
2657   CGF.EmitBranch(ContBlock);
2658 
2659   // Emit code to load the value if it was passed in memory.
2660 
2661   CGF.EmitBlock(InMemBlock);
2662   llvm::Value *MemAddr = EmitVAArgFromMemory(VAListAddr, Ty, CGF);
2663 
2664   // Return the appropriate result.
2665 
2666   CGF.EmitBlock(ContBlock);
2667   llvm::PHINode *ResAddr = CGF.Builder.CreatePHI(RegAddr->getType(), 2,
2668                                                  "vaarg.addr");
2669   ResAddr->addIncoming(RegAddr, InRegBlock);
2670   ResAddr->addIncoming(MemAddr, InMemBlock);
2671   return ResAddr;
2672 }
2673 
2674 ABIArgInfo WinX86_64ABIInfo::classify(QualType Ty, bool IsReturnType) const {
2675 
2676   if (Ty->isVoidType())
2677     return ABIArgInfo::getIgnore();
2678 
2679   if (const EnumType *EnumTy = Ty->getAs<EnumType>())
2680     Ty = EnumTy->getDecl()->getIntegerType();
2681 
2682   uint64_t Size = getContext().getTypeSize(Ty);
2683 
2684   const RecordType *RT = Ty->getAs<RecordType>();
2685   if (RT) {
2686     if (!IsReturnType) {
2687       if (CGCXXABI::RecordArgABI RAA = getRecordArgABI(RT, getCXXABI()))
2688         return ABIArgInfo::getIndirect(0, RAA == CGCXXABI::RAA_DirectInMemory);
2689     }
2690 
2691     if (RT->getDecl()->hasFlexibleArrayMember())
2692       return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
2693 
2694     // FIXME: mingw-w64-gcc emits 128-bit struct as i128
2695     if (Size == 128 && getTarget().getTriple().isWindowsGNUEnvironment())
2696       return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),
2697                                                           Size));
2698   }
2699 
2700   if (Ty->isMemberPointerType()) {
2701     // If the member pointer is represented by an LLVM int or ptr, pass it
2702     // directly.
2703     llvm::Type *LLTy = CGT.ConvertType(Ty);
2704     if (LLTy->isPointerTy() || LLTy->isIntegerTy())
2705       return ABIArgInfo::getDirect();
2706   }
2707 
2708   if (RT || Ty->isMemberPointerType()) {
2709     // MS x64 ABI requirement: "Any argument that doesn't fit in 8 bytes, or is
2710     // not 1, 2, 4, or 8 bytes, must be passed by reference."
2711     if (Size > 64 || !llvm::isPowerOf2_64(Size))
2712       return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
2713 
2714     // Otherwise, coerce it to a small integer.
2715     return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(), Size));
2716   }
2717 
2718   if (Ty->isPromotableIntegerType())
2719     return ABIArgInfo::getExtend();
2720 
2721   return ABIArgInfo::getDirect();
2722 }
2723 
2724 void WinX86_64ABIInfo::computeInfo(CGFunctionInfo &FI) const {
2725   if (!getCXXABI().classifyReturnType(FI))
2726     FI.getReturnInfo() = classify(FI.getReturnType(), true);
2727 
2728   for (auto &I : FI.arguments())
2729     I.info = classify(I.type, false);
2730 }
2731 
2732 llvm::Value *WinX86_64ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
2733                                       CodeGenFunction &CGF) const {
2734   llvm::Type *BPP = CGF.Int8PtrPtrTy;
2735 
2736   CGBuilderTy &Builder = CGF.Builder;
2737   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP,
2738                                                        "ap");
2739   llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
2740   llvm::Type *PTy =
2741     llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
2742   llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy);
2743 
2744   uint64_t Offset =
2745     llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, 8);
2746   llvm::Value *NextAddr =
2747     Builder.CreateGEP(Addr, llvm::ConstantInt::get(CGF.Int32Ty, Offset),
2748                       "ap.next");
2749   Builder.CreateStore(NextAddr, VAListAddrAsBPP);
2750 
2751   return AddrTyped;
2752 }
2753 
2754 namespace {
2755 
2756 class NaClX86_64ABIInfo : public ABIInfo {
2757  public:
2758   NaClX86_64ABIInfo(CodeGen::CodeGenTypes &CGT, bool HasAVX)
2759       : ABIInfo(CGT), PInfo(CGT), NInfo(CGT, HasAVX) {}
2760   void computeInfo(CGFunctionInfo &FI) const override;
2761   llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
2762                          CodeGenFunction &CGF) const override;
2763  private:
2764   PNaClABIInfo PInfo;  // Used for generating calls with pnaclcall callingconv.
2765   X86_64ABIInfo NInfo; // Used for everything else.
2766 };
2767 
2768 class NaClX86_64TargetCodeGenInfo : public TargetCodeGenInfo  {
2769  public:
2770   NaClX86_64TargetCodeGenInfo(CodeGen::CodeGenTypes &CGT, bool HasAVX)
2771       : TargetCodeGenInfo(new NaClX86_64ABIInfo(CGT, HasAVX)) {}
2772 };
2773 
2774 }
2775 
2776 void NaClX86_64ABIInfo::computeInfo(CGFunctionInfo &FI) const {
2777   if (FI.getASTCallingConvention() == CC_PnaclCall)
2778     PInfo.computeInfo(FI);
2779   else
2780     NInfo.computeInfo(FI);
2781 }
2782 
2783 llvm::Value *NaClX86_64ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
2784                                           CodeGenFunction &CGF) const {
2785   // Always use the native convention; calling pnacl-style varargs functions
2786   // is unuspported.
2787   return NInfo.EmitVAArg(VAListAddr, Ty, CGF);
2788 }
2789 
2790 
2791 // PowerPC-32
2792 
2793 namespace {
2794 class PPC32TargetCodeGenInfo : public DefaultTargetCodeGenInfo {
2795 public:
2796   PPC32TargetCodeGenInfo(CodeGenTypes &CGT) : DefaultTargetCodeGenInfo(CGT) {}
2797 
2798   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const override {
2799     // This is recovered from gcc output.
2800     return 1; // r1 is the dedicated stack pointer
2801   }
2802 
2803   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
2804                                llvm::Value *Address) const override;
2805 };
2806 
2807 }
2808 
2809 bool
2810 PPC32TargetCodeGenInfo::initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
2811                                                 llvm::Value *Address) const {
2812   // This is calculated from the LLVM and GCC tables and verified
2813   // against gcc output.  AFAIK all ABIs use the same encoding.
2814 
2815   CodeGen::CGBuilderTy &Builder = CGF.Builder;
2816 
2817   llvm::IntegerType *i8 = CGF.Int8Ty;
2818   llvm::Value *Four8 = llvm::ConstantInt::get(i8, 4);
2819   llvm::Value *Eight8 = llvm::ConstantInt::get(i8, 8);
2820   llvm::Value *Sixteen8 = llvm::ConstantInt::get(i8, 16);
2821 
2822   // 0-31: r0-31, the 4-byte general-purpose registers
2823   AssignToArrayRange(Builder, Address, Four8, 0, 31);
2824 
2825   // 32-63: fp0-31, the 8-byte floating-point registers
2826   AssignToArrayRange(Builder, Address, Eight8, 32, 63);
2827 
2828   // 64-76 are various 4-byte special-purpose registers:
2829   // 64: mq
2830   // 65: lr
2831   // 66: ctr
2832   // 67: ap
2833   // 68-75 cr0-7
2834   // 76: xer
2835   AssignToArrayRange(Builder, Address, Four8, 64, 76);
2836 
2837   // 77-108: v0-31, the 16-byte vector registers
2838   AssignToArrayRange(Builder, Address, Sixteen8, 77, 108);
2839 
2840   // 109: vrsave
2841   // 110: vscr
2842   // 111: spe_acc
2843   // 112: spefscr
2844   // 113: sfp
2845   AssignToArrayRange(Builder, Address, Four8, 109, 113);
2846 
2847   return false;
2848 }
2849 
2850 // PowerPC-64
2851 
2852 namespace {
2853 /// PPC64_SVR4_ABIInfo - The 64-bit PowerPC ELF (SVR4) ABI information.
2854 class PPC64_SVR4_ABIInfo : public DefaultABIInfo {
2855 
2856 public:
2857   PPC64_SVR4_ABIInfo(CodeGen::CodeGenTypes &CGT) : DefaultABIInfo(CGT) {}
2858 
2859   bool isPromotableTypeForABI(QualType Ty) const;
2860 
2861   ABIArgInfo classifyReturnType(QualType RetTy) const;
2862   ABIArgInfo classifyArgumentType(QualType Ty) const;
2863 
2864   // TODO: We can add more logic to computeInfo to improve performance.
2865   // Example: For aggregate arguments that fit in a register, we could
2866   // use getDirectInReg (as is done below for structs containing a single
2867   // floating-point value) to avoid pushing them to memory on function
2868   // entry.  This would require changing the logic in PPCISelLowering
2869   // when lowering the parameters in the caller and args in the callee.
2870   void computeInfo(CGFunctionInfo &FI) const override {
2871     if (!getCXXABI().classifyReturnType(FI))
2872       FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
2873     for (auto &I : FI.arguments()) {
2874       // We rely on the default argument classification for the most part.
2875       // One exception:  An aggregate containing a single floating-point
2876       // or vector item must be passed in a register if one is available.
2877       const Type *T = isSingleElementStruct(I.type, getContext());
2878       if (T) {
2879         const BuiltinType *BT = T->getAs<BuiltinType>();
2880         if (T->isVectorType() || (BT && BT->isFloatingPoint())) {
2881           QualType QT(T, 0);
2882           I.info = ABIArgInfo::getDirectInReg(CGT.ConvertType(QT));
2883           continue;
2884         }
2885       }
2886       I.info = classifyArgumentType(I.type);
2887     }
2888   }
2889 
2890   llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
2891                          CodeGenFunction &CGF) const override;
2892 };
2893 
2894 class PPC64_SVR4_TargetCodeGenInfo : public TargetCodeGenInfo {
2895 public:
2896   PPC64_SVR4_TargetCodeGenInfo(CodeGenTypes &CGT)
2897     : TargetCodeGenInfo(new PPC64_SVR4_ABIInfo(CGT)) {}
2898 
2899   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const override {
2900     // This is recovered from gcc output.
2901     return 1; // r1 is the dedicated stack pointer
2902   }
2903 
2904   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
2905                                llvm::Value *Address) const override;
2906 };
2907 
2908 class PPC64TargetCodeGenInfo : public DefaultTargetCodeGenInfo {
2909 public:
2910   PPC64TargetCodeGenInfo(CodeGenTypes &CGT) : DefaultTargetCodeGenInfo(CGT) {}
2911 
2912   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const override {
2913     // This is recovered from gcc output.
2914     return 1; // r1 is the dedicated stack pointer
2915   }
2916 
2917   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
2918                                llvm::Value *Address) const override;
2919 };
2920 
2921 }
2922 
2923 // Return true if the ABI requires Ty to be passed sign- or zero-
2924 // extended to 64 bits.
2925 bool
2926 PPC64_SVR4_ABIInfo::isPromotableTypeForABI(QualType Ty) const {
2927   // Treat an enum type as its underlying type.
2928   if (const EnumType *EnumTy = Ty->getAs<EnumType>())
2929     Ty = EnumTy->getDecl()->getIntegerType();
2930 
2931   // Promotable integer types are required to be promoted by the ABI.
2932   if (Ty->isPromotableIntegerType())
2933     return true;
2934 
2935   // In addition to the usual promotable integer types, we also need to
2936   // extend all 32-bit types, since the ABI requires promotion to 64 bits.
2937   if (const BuiltinType *BT = Ty->getAs<BuiltinType>())
2938     switch (BT->getKind()) {
2939     case BuiltinType::Int:
2940     case BuiltinType::UInt:
2941       return true;
2942     default:
2943       break;
2944     }
2945 
2946   return false;
2947 }
2948 
2949 ABIArgInfo
2950 PPC64_SVR4_ABIInfo::classifyArgumentType(QualType Ty) const {
2951   if (Ty->isAnyComplexType())
2952     return ABIArgInfo::getDirect();
2953 
2954   if (isAggregateTypeForABI(Ty)) {
2955     if (CGCXXABI::RecordArgABI RAA = getRecordArgABI(Ty, getCXXABI()))
2956       return ABIArgInfo::getIndirect(0, RAA == CGCXXABI::RAA_DirectInMemory);
2957 
2958     return ABIArgInfo::getIndirect(0);
2959   }
2960 
2961   return (isPromotableTypeForABI(Ty) ?
2962           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
2963 }
2964 
2965 ABIArgInfo
2966 PPC64_SVR4_ABIInfo::classifyReturnType(QualType RetTy) const {
2967   if (RetTy->isVoidType())
2968     return ABIArgInfo::getIgnore();
2969 
2970   if (RetTy->isAnyComplexType())
2971     return ABIArgInfo::getDirect();
2972 
2973   if (isAggregateTypeForABI(RetTy))
2974     return ABIArgInfo::getIndirect(0);
2975 
2976   return (isPromotableTypeForABI(RetTy) ?
2977           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
2978 }
2979 
2980 // Based on ARMABIInfo::EmitVAArg, adjusted for 64-bit machine.
2981 llvm::Value *PPC64_SVR4_ABIInfo::EmitVAArg(llvm::Value *VAListAddr,
2982                                            QualType Ty,
2983                                            CodeGenFunction &CGF) const {
2984   llvm::Type *BP = CGF.Int8PtrTy;
2985   llvm::Type *BPP = CGF.Int8PtrPtrTy;
2986 
2987   CGBuilderTy &Builder = CGF.Builder;
2988   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP, "ap");
2989   llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
2990 
2991   // Update the va_list pointer.  The pointer should be bumped by the
2992   // size of the object.  We can trust getTypeSize() except for a complex
2993   // type whose base type is smaller than a doubleword.  For these, the
2994   // size of the object is 16 bytes; see below for further explanation.
2995   unsigned SizeInBytes = CGF.getContext().getTypeSize(Ty) / 8;
2996   QualType BaseTy;
2997   unsigned CplxBaseSize = 0;
2998 
2999   if (const ComplexType *CTy = Ty->getAs<ComplexType>()) {
3000     BaseTy = CTy->getElementType();
3001     CplxBaseSize = CGF.getContext().getTypeSize(BaseTy) / 8;
3002     if (CplxBaseSize < 8)
3003       SizeInBytes = 16;
3004   }
3005 
3006   unsigned Offset = llvm::RoundUpToAlignment(SizeInBytes, 8);
3007   llvm::Value *NextAddr =
3008     Builder.CreateGEP(Addr, llvm::ConstantInt::get(CGF.Int64Ty, Offset),
3009                       "ap.next");
3010   Builder.CreateStore(NextAddr, VAListAddrAsBPP);
3011 
3012   // If we have a complex type and the base type is smaller than 8 bytes,
3013   // the ABI calls for the real and imaginary parts to be right-adjusted
3014   // in separate doublewords.  However, Clang expects us to produce a
3015   // pointer to a structure with the two parts packed tightly.  So generate
3016   // loads of the real and imaginary parts relative to the va_list pointer,
3017   // and store them to a temporary structure.
3018   if (CplxBaseSize && CplxBaseSize < 8) {
3019     llvm::Value *RealAddr = Builder.CreatePtrToInt(Addr, CGF.Int64Ty);
3020     llvm::Value *ImagAddr = RealAddr;
3021     RealAddr = Builder.CreateAdd(RealAddr, Builder.getInt64(8 - CplxBaseSize));
3022     ImagAddr = Builder.CreateAdd(ImagAddr, Builder.getInt64(16 - CplxBaseSize));
3023     llvm::Type *PBaseTy = llvm::PointerType::getUnqual(CGF.ConvertType(BaseTy));
3024     RealAddr = Builder.CreateIntToPtr(RealAddr, PBaseTy);
3025     ImagAddr = Builder.CreateIntToPtr(ImagAddr, PBaseTy);
3026     llvm::Value *Real = Builder.CreateLoad(RealAddr, false, ".vareal");
3027     llvm::Value *Imag = Builder.CreateLoad(ImagAddr, false, ".vaimag");
3028     llvm::Value *Ptr = CGF.CreateTempAlloca(CGT.ConvertTypeForMem(Ty),
3029                                             "vacplx");
3030     llvm::Value *RealPtr = Builder.CreateStructGEP(Ptr, 0, ".real");
3031     llvm::Value *ImagPtr = Builder.CreateStructGEP(Ptr, 1, ".imag");
3032     Builder.CreateStore(Real, RealPtr, false);
3033     Builder.CreateStore(Imag, ImagPtr, false);
3034     return Ptr;
3035   }
3036 
3037   // If the argument is smaller than 8 bytes, it is right-adjusted in
3038   // its doubleword slot.  Adjust the pointer to pick it up from the
3039   // correct offset.
3040   if (SizeInBytes < 8) {
3041     llvm::Value *AddrAsInt = Builder.CreatePtrToInt(Addr, CGF.Int64Ty);
3042     AddrAsInt = Builder.CreateAdd(AddrAsInt, Builder.getInt64(8 - SizeInBytes));
3043     Addr = Builder.CreateIntToPtr(AddrAsInt, BP);
3044   }
3045 
3046   llvm::Type *PTy = llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
3047   return Builder.CreateBitCast(Addr, PTy);
3048 }
3049 
3050 static bool
3051 PPC64_initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
3052                               llvm::Value *Address) {
3053   // This is calculated from the LLVM and GCC tables and verified
3054   // against gcc output.  AFAIK all ABIs use the same encoding.
3055 
3056   CodeGen::CGBuilderTy &Builder = CGF.Builder;
3057 
3058   llvm::IntegerType *i8 = CGF.Int8Ty;
3059   llvm::Value *Four8 = llvm::ConstantInt::get(i8, 4);
3060   llvm::Value *Eight8 = llvm::ConstantInt::get(i8, 8);
3061   llvm::Value *Sixteen8 = llvm::ConstantInt::get(i8, 16);
3062 
3063   // 0-31: r0-31, the 8-byte general-purpose registers
3064   AssignToArrayRange(Builder, Address, Eight8, 0, 31);
3065 
3066   // 32-63: fp0-31, the 8-byte floating-point registers
3067   AssignToArrayRange(Builder, Address, Eight8, 32, 63);
3068 
3069   // 64-76 are various 4-byte special-purpose registers:
3070   // 64: mq
3071   // 65: lr
3072   // 66: ctr
3073   // 67: ap
3074   // 68-75 cr0-7
3075   // 76: xer
3076   AssignToArrayRange(Builder, Address, Four8, 64, 76);
3077 
3078   // 77-108: v0-31, the 16-byte vector registers
3079   AssignToArrayRange(Builder, Address, Sixteen8, 77, 108);
3080 
3081   // 109: vrsave
3082   // 110: vscr
3083   // 111: spe_acc
3084   // 112: spefscr
3085   // 113: sfp
3086   AssignToArrayRange(Builder, Address, Four8, 109, 113);
3087 
3088   return false;
3089 }
3090 
3091 bool
3092 PPC64_SVR4_TargetCodeGenInfo::initDwarfEHRegSizeTable(
3093   CodeGen::CodeGenFunction &CGF,
3094   llvm::Value *Address) const {
3095 
3096   return PPC64_initDwarfEHRegSizeTable(CGF, Address);
3097 }
3098 
3099 bool
3100 PPC64TargetCodeGenInfo::initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
3101                                                 llvm::Value *Address) const {
3102 
3103   return PPC64_initDwarfEHRegSizeTable(CGF, Address);
3104 }
3105 
3106 //===----------------------------------------------------------------------===//
3107 // ARM64 ABI Implementation
3108 //===----------------------------------------------------------------------===//
3109 
3110 namespace {
3111 
3112 class ARM64ABIInfo : public ABIInfo {
3113 public:
3114   enum ABIKind {
3115     AAPCS = 0,
3116     DarwinPCS
3117   };
3118 
3119 private:
3120   ABIKind Kind;
3121 
3122 public:
3123   ARM64ABIInfo(CodeGenTypes &CGT, ABIKind Kind) : ABIInfo(CGT), Kind(Kind) {}
3124 
3125 private:
3126   ABIKind getABIKind() const { return Kind; }
3127   bool isDarwinPCS() const { return Kind == DarwinPCS; }
3128 
3129   ABIArgInfo classifyReturnType(QualType RetTy) const;
3130   ABIArgInfo classifyArgumentType(QualType RetTy, unsigned &AllocatedVFP,
3131                                   bool &IsHA, unsigned &AllocatedGPR,
3132                                   bool &IsSmallAggr, bool IsNamedArg) const;
3133   bool isIllegalVectorType(QualType Ty) const;
3134 
3135   virtual void computeInfo(CGFunctionInfo &FI) const {
3136     // To correctly handle Homogeneous Aggregate, we need to keep track of the
3137     // number of SIMD and Floating-point registers allocated so far.
3138     // If the argument is an HFA or an HVA and there are sufficient unallocated
3139     // SIMD and Floating-point registers, then the argument is allocated to SIMD
3140     // and Floating-point Registers (with one register per member of the HFA or
3141     // HVA). Otherwise, the NSRN is set to 8.
3142     unsigned AllocatedVFP = 0;
3143 
3144     // To correctly handle small aggregates, we need to keep track of the number
3145     // of GPRs allocated so far. If the small aggregate can't all fit into
3146     // registers, it will be on stack. We don't allow the aggregate to be
3147     // partially in registers.
3148     unsigned AllocatedGPR = 0;
3149 
3150     // Find the number of named arguments. Variadic arguments get special
3151     // treatment with the Darwin ABI.
3152     unsigned NumRequiredArgs = (FI.isVariadic() ?
3153                                 FI.getRequiredArgs().getNumRequiredArgs() :
3154                                 FI.arg_size());
3155 
3156     if (!getCXXABI().classifyReturnType(FI))
3157       FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
3158     for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
3159          it != ie; ++it) {
3160       unsigned PreAllocation = AllocatedVFP, PreGPR = AllocatedGPR;
3161       bool IsHA = false, IsSmallAggr = false;
3162       const unsigned NumVFPs = 8;
3163       const unsigned NumGPRs = 8;
3164       bool IsNamedArg = ((it - FI.arg_begin()) <
3165                          static_cast<signed>(NumRequiredArgs));
3166       it->info = classifyArgumentType(it->type, AllocatedVFP, IsHA,
3167                                       AllocatedGPR, IsSmallAggr, IsNamedArg);
3168 
3169       // Under AAPCS the 64-bit stack slot alignment means we can't pass HAs
3170       // as sequences of floats since they'll get "holes" inserted as
3171       // padding by the back end.
3172       if (IsHA && AllocatedVFP > NumVFPs && !isDarwinPCS() &&
3173           getContext().getTypeAlign(it->type) < 64) {
3174         uint32_t NumStackSlots = getContext().getTypeSize(it->type);
3175         NumStackSlots = llvm::RoundUpToAlignment(NumStackSlots, 64) / 64;
3176 
3177         llvm::Type *CoerceTy = llvm::ArrayType::get(
3178             llvm::Type::getDoubleTy(getVMContext()), NumStackSlots);
3179         it->info = ABIArgInfo::getDirect(CoerceTy);
3180       }
3181 
3182       // If we do not have enough VFP registers for the HA, any VFP registers
3183       // that are unallocated are marked as unavailable. To achieve this, we add
3184       // padding of (NumVFPs - PreAllocation) floats.
3185       if (IsHA && AllocatedVFP > NumVFPs && PreAllocation < NumVFPs) {
3186         llvm::Type *PaddingTy = llvm::ArrayType::get(
3187             llvm::Type::getFloatTy(getVMContext()), NumVFPs - PreAllocation);
3188         it->info.setPaddingType(PaddingTy);
3189       }
3190 
3191       // If we do not have enough GPRs for the small aggregate, any GPR regs
3192       // that are unallocated are marked as unavailable.
3193       if (IsSmallAggr && AllocatedGPR > NumGPRs && PreGPR < NumGPRs) {
3194         llvm::Type *PaddingTy = llvm::ArrayType::get(
3195             llvm::Type::getInt32Ty(getVMContext()), NumGPRs - PreGPR);
3196         it->info =
3197             ABIArgInfo::getDirect(it->info.getCoerceToType(), 0, PaddingTy);
3198       }
3199     }
3200   }
3201 
3202   llvm::Value *EmitDarwinVAArg(llvm::Value *VAListAddr, QualType Ty,
3203                                CodeGenFunction &CGF) const;
3204 
3205   llvm::Value *EmitAAPCSVAArg(llvm::Value *VAListAddr, QualType Ty,
3206                               CodeGenFunction &CGF) const;
3207 
3208   virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
3209                                  CodeGenFunction &CGF) const {
3210     return isDarwinPCS() ? EmitDarwinVAArg(VAListAddr, Ty, CGF)
3211                          : EmitAAPCSVAArg(VAListAddr, Ty, CGF);
3212   }
3213 };
3214 
3215 class ARM64TargetCodeGenInfo : public TargetCodeGenInfo {
3216 public:
3217   ARM64TargetCodeGenInfo(CodeGenTypes &CGT, ARM64ABIInfo::ABIKind Kind)
3218       : TargetCodeGenInfo(new ARM64ABIInfo(CGT, Kind)) {}
3219 
3220   StringRef getARCRetainAutoreleasedReturnValueMarker() const {
3221     return "mov\tfp, fp\t\t; marker for objc_retainAutoreleaseReturnValue";
3222   }
3223 
3224   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const { return 31; }
3225 
3226   virtual bool doesReturnSlotInterfereWithArgs() const { return false; }
3227 };
3228 }
3229 
3230 static bool isHomogeneousAggregate(QualType Ty, const Type *&Base,
3231                                    ASTContext &Context,
3232                                    uint64_t *HAMembers = 0);
3233 
3234 ABIArgInfo ARM64ABIInfo::classifyArgumentType(QualType Ty,
3235                                               unsigned &AllocatedVFP,
3236                                               bool &IsHA,
3237                                               unsigned &AllocatedGPR,
3238                                               bool &IsSmallAggr,
3239                                               bool IsNamedArg) const {
3240   // Handle illegal vector types here.
3241   if (isIllegalVectorType(Ty)) {
3242     uint64_t Size = getContext().getTypeSize(Ty);
3243     if (Size <= 32) {
3244       llvm::Type *ResType = llvm::Type::getInt32Ty(getVMContext());
3245       AllocatedGPR++;
3246       return ABIArgInfo::getDirect(ResType);
3247     }
3248     if (Size == 64) {
3249       llvm::Type *ResType =
3250           llvm::VectorType::get(llvm::Type::getInt32Ty(getVMContext()), 2);
3251       AllocatedVFP++;
3252       return ABIArgInfo::getDirect(ResType);
3253     }
3254     if (Size == 128) {
3255       llvm::Type *ResType =
3256           llvm::VectorType::get(llvm::Type::getInt32Ty(getVMContext()), 4);
3257       AllocatedVFP++;
3258       return ABIArgInfo::getDirect(ResType);
3259     }
3260     AllocatedGPR++;
3261     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
3262   }
3263   if (Ty->isVectorType())
3264     // Size of a legal vector should be either 64 or 128.
3265     AllocatedVFP++;
3266   if (const BuiltinType *BT = Ty->getAs<BuiltinType>()) {
3267     if (BT->getKind() == BuiltinType::Half ||
3268         BT->getKind() == BuiltinType::Float ||
3269         BT->getKind() == BuiltinType::Double ||
3270         BT->getKind() == BuiltinType::LongDouble)
3271       AllocatedVFP++;
3272   }
3273 
3274   if (!isAggregateTypeForABI(Ty)) {
3275     // Treat an enum type as its underlying type.
3276     if (const EnumType *EnumTy = Ty->getAs<EnumType>())
3277       Ty = EnumTy->getDecl()->getIntegerType();
3278 
3279     if (!Ty->isFloatingType() && !Ty->isVectorType()) {
3280       unsigned Alignment = getContext().getTypeAlign(Ty);
3281       if (!isDarwinPCS() && Alignment > 64)
3282         AllocatedGPR = llvm::RoundUpToAlignment(AllocatedGPR, Alignment / 64);
3283 
3284       int RegsNeeded = getContext().getTypeSize(Ty) > 64 ? 2 : 1;
3285       AllocatedGPR += RegsNeeded;
3286     }
3287     return (Ty->isPromotableIntegerType() && isDarwinPCS()
3288                 ? ABIArgInfo::getExtend()
3289                 : ABIArgInfo::getDirect());
3290   }
3291 
3292   // Structures with either a non-trivial destructor or a non-trivial
3293   // copy constructor are always indirect.
3294   if (CGCXXABI::RecordArgABI RAA = getRecordArgABI(Ty, getCXXABI())) {
3295     AllocatedGPR++;
3296     return ABIArgInfo::getIndirect(0, /*ByVal=*/RAA ==
3297                                           CGCXXABI::RAA_DirectInMemory);
3298   }
3299 
3300   // Empty records are always ignored on Darwin, but actually passed in C++ mode
3301   // elsewhere for GNU compatibility.
3302   if (isEmptyRecord(getContext(), Ty, true)) {
3303     if (!getContext().getLangOpts().CPlusPlus || isDarwinPCS())
3304       return ABIArgInfo::getIgnore();
3305 
3306     ++AllocatedGPR;
3307     return ABIArgInfo::getDirect(llvm::Type::getInt8Ty(getVMContext()));
3308   }
3309 
3310   // Homogeneous Floating-point Aggregates (HFAs) need to be expanded.
3311   const Type *Base = 0;
3312   uint64_t Members = 0;
3313   if (isHomogeneousAggregate(Ty, Base, getContext(), &Members)) {
3314     IsHA = true;
3315     if (!IsNamedArg && isDarwinPCS()) {
3316       // With the Darwin ABI, variadic arguments are always passed on the stack
3317       // and should not be expanded. Treat variadic HFAs as arrays of doubles.
3318       uint64_t Size = getContext().getTypeSize(Ty);
3319       llvm::Type *BaseTy = llvm::Type::getDoubleTy(getVMContext());
3320       return ABIArgInfo::getDirect(llvm::ArrayType::get(BaseTy, Size / 64));
3321     }
3322     AllocatedVFP += Members;
3323     return ABIArgInfo::getExpand();
3324   }
3325 
3326   // Aggregates <= 16 bytes are passed directly in registers or on the stack.
3327   uint64_t Size = getContext().getTypeSize(Ty);
3328   if (Size <= 128) {
3329     unsigned Alignment = getContext().getTypeAlign(Ty);
3330     if (!isDarwinPCS() && Alignment > 64)
3331       AllocatedGPR = llvm::RoundUpToAlignment(AllocatedGPR, Alignment / 64);
3332 
3333     Size = 64 * ((Size + 63) / 64); // round up to multiple of 8 bytes
3334     AllocatedGPR += Size / 64;
3335     IsSmallAggr = true;
3336     // We use a pair of i64 for 16-byte aggregate with 8-byte alignment.
3337     // For aggregates with 16-byte alignment, we use i128.
3338     if (Alignment < 128 && Size == 128) {
3339       llvm::Type *BaseTy = llvm::Type::getInt64Ty(getVMContext());
3340       return ABIArgInfo::getDirect(llvm::ArrayType::get(BaseTy, Size / 64));
3341     }
3342     return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(), Size));
3343   }
3344 
3345   AllocatedGPR++;
3346   return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
3347 }
3348 
3349 ABIArgInfo ARM64ABIInfo::classifyReturnType(QualType RetTy) const {
3350   if (RetTy->isVoidType())
3351     return ABIArgInfo::getIgnore();
3352 
3353   // Large vector types should be returned via memory.
3354   if (RetTy->isVectorType() && getContext().getTypeSize(RetTy) > 128)
3355     return ABIArgInfo::getIndirect(0);
3356 
3357   if (!isAggregateTypeForABI(RetTy)) {
3358     // Treat an enum type as its underlying type.
3359     if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
3360       RetTy = EnumTy->getDecl()->getIntegerType();
3361 
3362     return (RetTy->isPromotableIntegerType() && isDarwinPCS()
3363                 ? ABIArgInfo::getExtend()
3364                 : ABIArgInfo::getDirect());
3365   }
3366 
3367   if (isEmptyRecord(getContext(), RetTy, true))
3368     return ABIArgInfo::getIgnore();
3369 
3370   const Type *Base = 0;
3371   if (isHomogeneousAggregate(RetTy, Base, getContext()))
3372     // Homogeneous Floating-point Aggregates (HFAs) are returned directly.
3373     return ABIArgInfo::getDirect();
3374 
3375   // Aggregates <= 16 bytes are returned directly in registers or on the stack.
3376   uint64_t Size = getContext().getTypeSize(RetTy);
3377   if (Size <= 128) {
3378     Size = 64 * ((Size + 63) / 64); // round up to multiple of 8 bytes
3379     return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(), Size));
3380   }
3381 
3382   return ABIArgInfo::getIndirect(0);
3383 }
3384 
3385 /// isIllegalVectorType - check whether the vector type is legal for ARM64.
3386 bool ARM64ABIInfo::isIllegalVectorType(QualType Ty) const {
3387   if (const VectorType *VT = Ty->getAs<VectorType>()) {
3388     // Check whether VT is legal.
3389     unsigned NumElements = VT->getNumElements();
3390     uint64_t Size = getContext().getTypeSize(VT);
3391     // NumElements should be power of 2 between 1 and 16.
3392     if ((NumElements & (NumElements - 1)) != 0 || NumElements > 16)
3393       return true;
3394     return Size != 64 && (Size != 128 || NumElements == 1);
3395   }
3396   return false;
3397 }
3398 
3399 static llvm::Value *EmitAArch64VAArg(llvm::Value *VAListAddr, QualType Ty,
3400                                      int AllocatedGPR, int AllocatedVFP,
3401                                      bool IsIndirect, CodeGenFunction &CGF) {
3402   // The AArch64 va_list type and handling is specified in the Procedure Call
3403   // Standard, section B.4:
3404   //
3405   // struct {
3406   //   void *__stack;
3407   //   void *__gr_top;
3408   //   void *__vr_top;
3409   //   int __gr_offs;
3410   //   int __vr_offs;
3411   // };
3412 
3413   llvm::BasicBlock *MaybeRegBlock = CGF.createBasicBlock("vaarg.maybe_reg");
3414   llvm::BasicBlock *InRegBlock = CGF.createBasicBlock("vaarg.in_reg");
3415   llvm::BasicBlock *OnStackBlock = CGF.createBasicBlock("vaarg.on_stack");
3416   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("vaarg.end");
3417   auto &Ctx = CGF.getContext();
3418 
3419   llvm::Value *reg_offs_p = 0, *reg_offs = 0;
3420   int reg_top_index;
3421   int RegSize;
3422   if (AllocatedGPR) {
3423     assert(!AllocatedVFP && "Arguments never split between int & VFP regs");
3424     // 3 is the field number of __gr_offs
3425     reg_offs_p = CGF.Builder.CreateStructGEP(VAListAddr, 3, "gr_offs_p");
3426     reg_offs = CGF.Builder.CreateLoad(reg_offs_p, "gr_offs");
3427     reg_top_index = 1; // field number for __gr_top
3428     RegSize = 8 * AllocatedGPR;
3429   } else {
3430     assert(!AllocatedGPR && "Argument must go in VFP or int regs");
3431     // 4 is the field number of __vr_offs.
3432     reg_offs_p = CGF.Builder.CreateStructGEP(VAListAddr, 4, "vr_offs_p");
3433     reg_offs = CGF.Builder.CreateLoad(reg_offs_p, "vr_offs");
3434     reg_top_index = 2; // field number for __vr_top
3435     RegSize = 16 * AllocatedVFP;
3436   }
3437 
3438   //=======================================
3439   // Find out where argument was passed
3440   //=======================================
3441 
3442   // If reg_offs >= 0 we're already using the stack for this type of
3443   // argument. We don't want to keep updating reg_offs (in case it overflows,
3444   // though anyone passing 2GB of arguments, each at most 16 bytes, deserves
3445   // whatever they get).
3446   llvm::Value *UsingStack = 0;
3447   UsingStack = CGF.Builder.CreateICmpSGE(
3448       reg_offs, llvm::ConstantInt::get(CGF.Int32Ty, 0));
3449 
3450   CGF.Builder.CreateCondBr(UsingStack, OnStackBlock, MaybeRegBlock);
3451 
3452   // Otherwise, at least some kind of argument could go in these registers, the
3453   // question is whether this particular type is too big.
3454   CGF.EmitBlock(MaybeRegBlock);
3455 
3456   // Integer arguments may need to correct register alignment (for example a
3457   // "struct { __int128 a; };" gets passed in x_2N, x_{2N+1}). In this case we
3458   // align __gr_offs to calculate the potential address.
3459   if (AllocatedGPR && !IsIndirect && Ctx.getTypeAlign(Ty) > 64) {
3460     int Align = Ctx.getTypeAlign(Ty) / 8;
3461 
3462     reg_offs = CGF.Builder.CreateAdd(
3463         reg_offs, llvm::ConstantInt::get(CGF.Int32Ty, Align - 1),
3464         "align_regoffs");
3465     reg_offs = CGF.Builder.CreateAnd(
3466         reg_offs, llvm::ConstantInt::get(CGF.Int32Ty, -Align),
3467         "aligned_regoffs");
3468   }
3469 
3470   // Update the gr_offs/vr_offs pointer for next call to va_arg on this va_list.
3471   llvm::Value *NewOffset = 0;
3472   NewOffset = CGF.Builder.CreateAdd(
3473       reg_offs, llvm::ConstantInt::get(CGF.Int32Ty, RegSize), "new_reg_offs");
3474   CGF.Builder.CreateStore(NewOffset, reg_offs_p);
3475 
3476   // Now we're in a position to decide whether this argument really was in
3477   // registers or not.
3478   llvm::Value *InRegs = 0;
3479   InRegs = CGF.Builder.CreateICmpSLE(
3480       NewOffset, llvm::ConstantInt::get(CGF.Int32Ty, 0), "inreg");
3481 
3482   CGF.Builder.CreateCondBr(InRegs, InRegBlock, OnStackBlock);
3483 
3484   //=======================================
3485   // Argument was in registers
3486   //=======================================
3487 
3488   // Now we emit the code for if the argument was originally passed in
3489   // registers. First start the appropriate block:
3490   CGF.EmitBlock(InRegBlock);
3491 
3492   llvm::Value *reg_top_p = 0, *reg_top = 0;
3493   reg_top_p =
3494       CGF.Builder.CreateStructGEP(VAListAddr, reg_top_index, "reg_top_p");
3495   reg_top = CGF.Builder.CreateLoad(reg_top_p, "reg_top");
3496   llvm::Value *BaseAddr = CGF.Builder.CreateGEP(reg_top, reg_offs);
3497   llvm::Value *RegAddr = 0;
3498   llvm::Type *MemTy = llvm::PointerType::getUnqual(CGF.ConvertTypeForMem(Ty));
3499 
3500   if (IsIndirect) {
3501     // If it's been passed indirectly (actually a struct), whatever we find from
3502     // stored registers or on the stack will actually be a struct **.
3503     MemTy = llvm::PointerType::getUnqual(MemTy);
3504   }
3505 
3506   const Type *Base = 0;
3507   uint64_t NumMembers;
3508   bool IsHFA = isHomogeneousAggregate(Ty, Base, Ctx, &NumMembers);
3509   if (IsHFA && NumMembers > 1) {
3510     // Homogeneous aggregates passed in registers will have their elements split
3511     // and stored 16-bytes apart regardless of size (they're notionally in qN,
3512     // qN+1, ...). We reload and store into a temporary local variable
3513     // contiguously.
3514     assert(!IsIndirect && "Homogeneous aggregates should be passed directly");
3515     llvm::Type *BaseTy = CGF.ConvertType(QualType(Base, 0));
3516     llvm::Type *HFATy = llvm::ArrayType::get(BaseTy, NumMembers);
3517     llvm::Value *Tmp = CGF.CreateTempAlloca(HFATy);
3518     int Offset = 0;
3519 
3520     if (CGF.CGM.getDataLayout().isBigEndian() && Ctx.getTypeSize(Base) < 128)
3521       Offset = 16 - Ctx.getTypeSize(Base) / 8;
3522     for (unsigned i = 0; i < NumMembers; ++i) {
3523       llvm::Value *BaseOffset =
3524           llvm::ConstantInt::get(CGF.Int32Ty, 16 * i + Offset);
3525       llvm::Value *LoadAddr = CGF.Builder.CreateGEP(BaseAddr, BaseOffset);
3526       LoadAddr = CGF.Builder.CreateBitCast(
3527           LoadAddr, llvm::PointerType::getUnqual(BaseTy));
3528       llvm::Value *StoreAddr = CGF.Builder.CreateStructGEP(Tmp, i);
3529 
3530       llvm::Value *Elem = CGF.Builder.CreateLoad(LoadAddr);
3531       CGF.Builder.CreateStore(Elem, StoreAddr);
3532     }
3533 
3534     RegAddr = CGF.Builder.CreateBitCast(Tmp, MemTy);
3535   } else {
3536     // Otherwise the object is contiguous in memory
3537     unsigned BeAlign = reg_top_index == 2 ? 16 : 8;
3538     if (CGF.CGM.getDataLayout().isBigEndian() &&
3539         (IsHFA || !isAggregateTypeForABI(Ty)) &&
3540         Ctx.getTypeSize(Ty) < (BeAlign * 8)) {
3541       int Offset = BeAlign - Ctx.getTypeSize(Ty) / 8;
3542       BaseAddr = CGF.Builder.CreatePtrToInt(BaseAddr, CGF.Int64Ty);
3543 
3544       BaseAddr = CGF.Builder.CreateAdd(
3545           BaseAddr, llvm::ConstantInt::get(CGF.Int64Ty, Offset), "align_be");
3546 
3547       BaseAddr = CGF.Builder.CreateIntToPtr(BaseAddr, CGF.Int8PtrTy);
3548     }
3549 
3550     RegAddr = CGF.Builder.CreateBitCast(BaseAddr, MemTy);
3551   }
3552 
3553   CGF.EmitBranch(ContBlock);
3554 
3555   //=======================================
3556   // Argument was on the stack
3557   //=======================================
3558   CGF.EmitBlock(OnStackBlock);
3559 
3560   llvm::Value *stack_p = 0, *OnStackAddr = 0;
3561   stack_p = CGF.Builder.CreateStructGEP(VAListAddr, 0, "stack_p");
3562   OnStackAddr = CGF.Builder.CreateLoad(stack_p, "stack");
3563 
3564   // Again, stack arguments may need realigmnent. In this case both integer and
3565   // floating-point ones might be affected.
3566   if (!IsIndirect && Ctx.getTypeAlign(Ty) > 64) {
3567     int Align = Ctx.getTypeAlign(Ty) / 8;
3568 
3569     OnStackAddr = CGF.Builder.CreatePtrToInt(OnStackAddr, CGF.Int64Ty);
3570 
3571     OnStackAddr = CGF.Builder.CreateAdd(
3572         OnStackAddr, llvm::ConstantInt::get(CGF.Int64Ty, Align - 1),
3573         "align_stack");
3574     OnStackAddr = CGF.Builder.CreateAnd(
3575         OnStackAddr, llvm::ConstantInt::get(CGF.Int64Ty, -Align),
3576         "align_stack");
3577 
3578     OnStackAddr = CGF.Builder.CreateIntToPtr(OnStackAddr, CGF.Int8PtrTy);
3579   }
3580 
3581   uint64_t StackSize;
3582   if (IsIndirect)
3583     StackSize = 8;
3584   else
3585     StackSize = Ctx.getTypeSize(Ty) / 8;
3586 
3587   // All stack slots are 8 bytes
3588   StackSize = llvm::RoundUpToAlignment(StackSize, 8);
3589 
3590   llvm::Value *StackSizeC = llvm::ConstantInt::get(CGF.Int32Ty, StackSize);
3591   llvm::Value *NewStack =
3592       CGF.Builder.CreateGEP(OnStackAddr, StackSizeC, "new_stack");
3593 
3594   // Write the new value of __stack for the next call to va_arg
3595   CGF.Builder.CreateStore(NewStack, stack_p);
3596 
3597   if (CGF.CGM.getDataLayout().isBigEndian() && !isAggregateTypeForABI(Ty) &&
3598       Ctx.getTypeSize(Ty) < 64) {
3599     int Offset = 8 - Ctx.getTypeSize(Ty) / 8;
3600     OnStackAddr = CGF.Builder.CreatePtrToInt(OnStackAddr, CGF.Int64Ty);
3601 
3602     OnStackAddr = CGF.Builder.CreateAdd(
3603         OnStackAddr, llvm::ConstantInt::get(CGF.Int64Ty, Offset), "align_be");
3604 
3605     OnStackAddr = CGF.Builder.CreateIntToPtr(OnStackAddr, CGF.Int8PtrTy);
3606   }
3607 
3608   OnStackAddr = CGF.Builder.CreateBitCast(OnStackAddr, MemTy);
3609 
3610   CGF.EmitBranch(ContBlock);
3611 
3612   //=======================================
3613   // Tidy up
3614   //=======================================
3615   CGF.EmitBlock(ContBlock);
3616 
3617   llvm::PHINode *ResAddr = CGF.Builder.CreatePHI(MemTy, 2, "vaarg.addr");
3618   ResAddr->addIncoming(RegAddr, InRegBlock);
3619   ResAddr->addIncoming(OnStackAddr, OnStackBlock);
3620 
3621   if (IsIndirect)
3622     return CGF.Builder.CreateLoad(ResAddr, "vaarg.addr");
3623 
3624   return ResAddr;
3625 }
3626 
3627 llvm::Value *ARM64ABIInfo::EmitAAPCSVAArg(llvm::Value *VAListAddr, QualType Ty,
3628                                           CodeGenFunction &CGF) const {
3629 
3630   unsigned AllocatedGPR = 0, AllocatedVFP = 0;
3631   bool IsHA = false, IsSmallAggr = false;
3632   ABIArgInfo AI = classifyArgumentType(Ty, AllocatedVFP, IsHA, AllocatedGPR,
3633                                        IsSmallAggr, false /*IsNamedArg*/);
3634 
3635   return EmitAArch64VAArg(VAListAddr, Ty, AllocatedGPR, AllocatedVFP,
3636                           AI.isIndirect(), CGF);
3637 }
3638 
3639 llvm::Value *ARM64ABIInfo::EmitDarwinVAArg(llvm::Value *VAListAddr, QualType Ty,
3640                                            CodeGenFunction &CGF) const {
3641   // We do not support va_arg for aggregates or illegal vector types.
3642   // Lower VAArg here for these cases and use the LLVM va_arg instruction for
3643   // other cases.
3644   if (!isAggregateTypeForABI(Ty) && !isIllegalVectorType(Ty))
3645     return 0;
3646 
3647   uint64_t Size = CGF.getContext().getTypeSize(Ty) / 8;
3648   uint64_t Align = CGF.getContext().getTypeAlign(Ty) / 8;
3649 
3650   const Type *Base = 0;
3651   bool isHA = isHomogeneousAggregate(Ty, Base, getContext());
3652 
3653   bool isIndirect = false;
3654   // Arguments bigger than 16 bytes which aren't homogeneous aggregates should
3655   // be passed indirectly.
3656   if (Size > 16 && !isHA) {
3657     isIndirect = true;
3658     Size = 8;
3659     Align = 8;
3660   }
3661 
3662   llvm::Type *BP = llvm::Type::getInt8PtrTy(CGF.getLLVMContext());
3663   llvm::Type *BPP = llvm::PointerType::getUnqual(BP);
3664 
3665   CGBuilderTy &Builder = CGF.Builder;
3666   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP, "ap");
3667   llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
3668 
3669   if (isEmptyRecord(getContext(), Ty, true)) {
3670     // These are ignored for parameter passing purposes.
3671     llvm::Type *PTy = llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
3672     return Builder.CreateBitCast(Addr, PTy);
3673   }
3674 
3675   const uint64_t MinABIAlign = 8;
3676   if (Align > MinABIAlign) {
3677     llvm::Value *Offset = llvm::ConstantInt::get(CGF.Int32Ty, Align - 1);
3678     Addr = Builder.CreateGEP(Addr, Offset);
3679     llvm::Value *AsInt = Builder.CreatePtrToInt(Addr, CGF.Int64Ty);
3680     llvm::Value *Mask = llvm::ConstantInt::get(CGF.Int64Ty, ~(Align - 1));
3681     llvm::Value *Aligned = Builder.CreateAnd(AsInt, Mask);
3682     Addr = Builder.CreateIntToPtr(Aligned, BP, "ap.align");
3683   }
3684 
3685   uint64_t Offset = llvm::RoundUpToAlignment(Size, MinABIAlign);
3686   llvm::Value *NextAddr = Builder.CreateGEP(
3687       Addr, llvm::ConstantInt::get(CGF.Int32Ty, Offset), "ap.next");
3688   Builder.CreateStore(NextAddr, VAListAddrAsBPP);
3689 
3690   if (isIndirect)
3691     Addr = Builder.CreateLoad(Builder.CreateBitCast(Addr, BPP));
3692   llvm::Type *PTy = llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
3693   llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy);
3694 
3695   return AddrTyped;
3696 }
3697 
3698 //===----------------------------------------------------------------------===//
3699 // ARM ABI Implementation
3700 //===----------------------------------------------------------------------===//
3701 
3702 namespace {
3703 
3704 class ARMABIInfo : public ABIInfo {
3705 public:
3706   enum ABIKind {
3707     APCS = 0,
3708     AAPCS = 1,
3709     AAPCS_VFP
3710   };
3711 
3712 private:
3713   ABIKind Kind;
3714   mutable int VFPRegs[16];
3715   const unsigned NumVFPs;
3716   const unsigned NumGPRs;
3717   mutable unsigned AllocatedGPRs;
3718   mutable unsigned AllocatedVFPs;
3719 
3720 public:
3721   ARMABIInfo(CodeGenTypes &CGT, ABIKind _Kind) : ABIInfo(CGT), Kind(_Kind),
3722     NumVFPs(16), NumGPRs(4) {
3723     setRuntimeCC();
3724     resetAllocatedRegs();
3725   }
3726 
3727   bool isEABI() const {
3728     switch (getTarget().getTriple().getEnvironment()) {
3729     case llvm::Triple::Android:
3730     case llvm::Triple::EABI:
3731     case llvm::Triple::EABIHF:
3732     case llvm::Triple::GNUEABI:
3733     case llvm::Triple::GNUEABIHF:
3734       return true;
3735     default:
3736       return false;
3737     }
3738   }
3739 
3740   bool isEABIHF() const {
3741     switch (getTarget().getTriple().getEnvironment()) {
3742     case llvm::Triple::EABIHF:
3743     case llvm::Triple::GNUEABIHF:
3744       return true;
3745     default:
3746       return false;
3747     }
3748   }
3749 
3750   ABIKind getABIKind() const { return Kind; }
3751 
3752 private:
3753   ABIArgInfo classifyReturnType(QualType RetTy, bool isVariadic) const;
3754   ABIArgInfo classifyArgumentType(QualType RetTy, bool isVariadic,
3755                                   bool &IsCPRC) const;
3756   bool isIllegalVectorType(QualType Ty) const;
3757 
3758   void computeInfo(CGFunctionInfo &FI) const override;
3759 
3760   llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
3761                          CodeGenFunction &CGF) const override;
3762 
3763   llvm::CallingConv::ID getLLVMDefaultCC() const;
3764   llvm::CallingConv::ID getABIDefaultCC() const;
3765   void setRuntimeCC();
3766 
3767   void markAllocatedGPRs(unsigned Alignment, unsigned NumRequired) const;
3768   void markAllocatedVFPs(unsigned Alignment, unsigned NumRequired) const;
3769   void resetAllocatedRegs(void) const;
3770 };
3771 
3772 class ARMTargetCodeGenInfo : public TargetCodeGenInfo {
3773 public:
3774   ARMTargetCodeGenInfo(CodeGenTypes &CGT, ARMABIInfo::ABIKind K)
3775     :TargetCodeGenInfo(new ARMABIInfo(CGT, K)) {}
3776 
3777   const ARMABIInfo &getABIInfo() const {
3778     return static_cast<const ARMABIInfo&>(TargetCodeGenInfo::getABIInfo());
3779   }
3780 
3781   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const override {
3782     return 13;
3783   }
3784 
3785   StringRef getARCRetainAutoreleasedReturnValueMarker() const override {
3786     return "mov\tr7, r7\t\t@ marker for objc_retainAutoreleaseReturnValue";
3787   }
3788 
3789   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
3790                                llvm::Value *Address) const override {
3791     llvm::Value *Four8 = llvm::ConstantInt::get(CGF.Int8Ty, 4);
3792 
3793     // 0-15 are the 16 integer registers.
3794     AssignToArrayRange(CGF.Builder, Address, Four8, 0, 15);
3795     return false;
3796   }
3797 
3798   unsigned getSizeOfUnwindException() const override {
3799     if (getABIInfo().isEABI()) return 88;
3800     return TargetCodeGenInfo::getSizeOfUnwindException();
3801   }
3802 
3803   void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
3804                            CodeGen::CodeGenModule &CGM) const override {
3805     const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
3806     if (!FD)
3807       return;
3808 
3809     const ARMInterruptAttr *Attr = FD->getAttr<ARMInterruptAttr>();
3810     if (!Attr)
3811       return;
3812 
3813     const char *Kind;
3814     switch (Attr->getInterrupt()) {
3815     case ARMInterruptAttr::Generic: Kind = ""; break;
3816     case ARMInterruptAttr::IRQ:     Kind = "IRQ"; break;
3817     case ARMInterruptAttr::FIQ:     Kind = "FIQ"; break;
3818     case ARMInterruptAttr::SWI:     Kind = "SWI"; break;
3819     case ARMInterruptAttr::ABORT:   Kind = "ABORT"; break;
3820     case ARMInterruptAttr::UNDEF:   Kind = "UNDEF"; break;
3821     }
3822 
3823     llvm::Function *Fn = cast<llvm::Function>(GV);
3824 
3825     Fn->addFnAttr("interrupt", Kind);
3826 
3827     if (cast<ARMABIInfo>(getABIInfo()).getABIKind() == ARMABIInfo::APCS)
3828       return;
3829 
3830     // AAPCS guarantees that sp will be 8-byte aligned on any public interface,
3831     // however this is not necessarily true on taking any interrupt. Instruct
3832     // the backend to perform a realignment as part of the function prologue.
3833     llvm::AttrBuilder B;
3834     B.addStackAlignmentAttr(8);
3835     Fn->addAttributes(llvm::AttributeSet::FunctionIndex,
3836                       llvm::AttributeSet::get(CGM.getLLVMContext(),
3837                                               llvm::AttributeSet::FunctionIndex,
3838                                               B));
3839   }
3840 
3841 };
3842 
3843 }
3844 
3845 void ARMABIInfo::computeInfo(CGFunctionInfo &FI) const {
3846   // To correctly handle Homogeneous Aggregate, we need to keep track of the
3847   // VFP registers allocated so far.
3848   // C.1.vfp If the argument is a VFP CPRC and there are sufficient consecutive
3849   // VFP registers of the appropriate type unallocated then the argument is
3850   // allocated to the lowest-numbered sequence of such registers.
3851   // C.2.vfp If the argument is a VFP CPRC then any VFP registers that are
3852   // unallocated are marked as unavailable.
3853   resetAllocatedRegs();
3854 
3855   if (getCXXABI().classifyReturnType(FI)) {
3856     if (FI.getReturnInfo().isIndirect())
3857       markAllocatedGPRs(1, 1);
3858   } else {
3859     FI.getReturnInfo() = classifyReturnType(FI.getReturnType(), FI.isVariadic());
3860   }
3861   for (auto &I : FI.arguments()) {
3862     unsigned PreAllocationVFPs = AllocatedVFPs;
3863     unsigned PreAllocationGPRs = AllocatedGPRs;
3864     bool IsCPRC = false;
3865     // 6.1.2.3 There is one VFP co-processor register class using registers
3866     // s0-s15 (d0-d7) for passing arguments.
3867     I.info = classifyArgumentType(I.type, FI.isVariadic(), IsCPRC);
3868 
3869     // If we have allocated some arguments onto the stack (due to running
3870     // out of VFP registers), we cannot split an argument between GPRs and
3871     // the stack. If this situation occurs, we add padding to prevent the
3872     // GPRs from being used. In this situation, the current argument could
3873     // only be allocated by rule C.8, so rule C.6 would mark these GPRs as
3874     // unusable anyway.
3875     const bool StackUsed = PreAllocationGPRs > NumGPRs || PreAllocationVFPs > NumVFPs;
3876     if (!IsCPRC && PreAllocationGPRs < NumGPRs && AllocatedGPRs > NumGPRs && StackUsed) {
3877       llvm::Type *PaddingTy = llvm::ArrayType::get(
3878           llvm::Type::getInt32Ty(getVMContext()), NumGPRs - PreAllocationGPRs);
3879       if (I.info.canHaveCoerceToType()) {
3880         I.info = ABIArgInfo::getDirect(I.info.getCoerceToType() /* type */, 0 /* offset */,
3881                                        PaddingTy);
3882       } else {
3883         I.info = ABIArgInfo::getDirect(nullptr /* type */, 0 /* offset */,
3884                                        PaddingTy);
3885       }
3886     }
3887   }
3888 
3889   // Always honor user-specified calling convention.
3890   if (FI.getCallingConvention() != llvm::CallingConv::C)
3891     return;
3892 
3893   llvm::CallingConv::ID cc = getRuntimeCC();
3894   if (cc != llvm::CallingConv::C)
3895     FI.setEffectiveCallingConvention(cc);
3896 }
3897 
3898 /// Return the default calling convention that LLVM will use.
3899 llvm::CallingConv::ID ARMABIInfo::getLLVMDefaultCC() const {
3900   // The default calling convention that LLVM will infer.
3901   if (isEABIHF())
3902     return llvm::CallingConv::ARM_AAPCS_VFP;
3903   else if (isEABI())
3904     return llvm::CallingConv::ARM_AAPCS;
3905   else
3906     return llvm::CallingConv::ARM_APCS;
3907 }
3908 
3909 /// Return the calling convention that our ABI would like us to use
3910 /// as the C calling convention.
3911 llvm::CallingConv::ID ARMABIInfo::getABIDefaultCC() const {
3912   switch (getABIKind()) {
3913   case APCS: return llvm::CallingConv::ARM_APCS;
3914   case AAPCS: return llvm::CallingConv::ARM_AAPCS;
3915   case AAPCS_VFP: return llvm::CallingConv::ARM_AAPCS_VFP;
3916   }
3917   llvm_unreachable("bad ABI kind");
3918 }
3919 
3920 void ARMABIInfo::setRuntimeCC() {
3921   assert(getRuntimeCC() == llvm::CallingConv::C);
3922 
3923   // Don't muddy up the IR with a ton of explicit annotations if
3924   // they'd just match what LLVM will infer from the triple.
3925   llvm::CallingConv::ID abiCC = getABIDefaultCC();
3926   if (abiCC != getLLVMDefaultCC())
3927     RuntimeCC = abiCC;
3928 }
3929 
3930 /// isHomogeneousAggregate - Return true if a type is an AAPCS-VFP homogeneous
3931 /// aggregate.  If HAMembers is non-null, the number of base elements
3932 /// contained in the type is returned through it; this is used for the
3933 /// recursive calls that check aggregate component types.
3934 static bool isHomogeneousAggregate(QualType Ty, const Type *&Base,
3935                                    ASTContext &Context, uint64_t *HAMembers) {
3936   uint64_t Members = 0;
3937   if (const ConstantArrayType *AT = Context.getAsConstantArrayType(Ty)) {
3938     if (!isHomogeneousAggregate(AT->getElementType(), Base, Context, &Members))
3939       return false;
3940     Members *= AT->getSize().getZExtValue();
3941   } else if (const RecordType *RT = Ty->getAs<RecordType>()) {
3942     const RecordDecl *RD = RT->getDecl();
3943     if (RD->hasFlexibleArrayMember())
3944       return false;
3945 
3946     Members = 0;
3947     for (const auto *FD : RD->fields()) {
3948       uint64_t FldMembers;
3949       if (!isHomogeneousAggregate(FD->getType(), Base, Context, &FldMembers))
3950         return false;
3951 
3952       Members = (RD->isUnion() ?
3953                  std::max(Members, FldMembers) : Members + FldMembers);
3954     }
3955   } else {
3956     Members = 1;
3957     if (const ComplexType *CT = Ty->getAs<ComplexType>()) {
3958       Members = 2;
3959       Ty = CT->getElementType();
3960     }
3961 
3962     // Homogeneous aggregates for AAPCS-VFP must have base types of float,
3963     // double, or 64-bit or 128-bit vectors.
3964     if (const BuiltinType *BT = Ty->getAs<BuiltinType>()) {
3965       if (BT->getKind() != BuiltinType::Float &&
3966           BT->getKind() != BuiltinType::Double &&
3967           BT->getKind() != BuiltinType::LongDouble)
3968         return false;
3969     } else if (const VectorType *VT = Ty->getAs<VectorType>()) {
3970       unsigned VecSize = Context.getTypeSize(VT);
3971       if (VecSize != 64 && VecSize != 128)
3972         return false;
3973     } else {
3974       return false;
3975     }
3976 
3977     // The base type must be the same for all members.  Vector types of the
3978     // same total size are treated as being equivalent here.
3979     const Type *TyPtr = Ty.getTypePtr();
3980     if (!Base)
3981       Base = TyPtr;
3982 
3983     if (Base != TyPtr) {
3984       // Homogeneous aggregates are defined as containing members with the
3985       // same machine type. There are two cases in which two members have
3986       // different TypePtrs but the same machine type:
3987 
3988       // 1) Vectors of the same length, regardless of the type and number
3989       //    of their members.
3990       const bool SameLengthVectors = Base->isVectorType() && TyPtr->isVectorType()
3991         && (Context.getTypeSize(Base) == Context.getTypeSize(TyPtr));
3992 
3993       // 2) In the 32-bit AAPCS, `double' and `long double' have the same
3994       //    machine type. This is not the case for the 64-bit AAPCS.
3995       const bool SameSizeDoubles =
3996            (   (   Base->isSpecificBuiltinType(BuiltinType::Double)
3997                 && TyPtr->isSpecificBuiltinType(BuiltinType::LongDouble))
3998             || (   Base->isSpecificBuiltinType(BuiltinType::LongDouble)
3999                 && TyPtr->isSpecificBuiltinType(BuiltinType::Double)))
4000         && (Context.getTypeSize(Base) == Context.getTypeSize(TyPtr));
4001 
4002       if (!SameLengthVectors && !SameSizeDoubles)
4003         return false;
4004     }
4005   }
4006 
4007   // Homogeneous Aggregates can have at most 4 members of the base type.
4008   if (HAMembers)
4009     *HAMembers = Members;
4010 
4011   return (Members > 0 && Members <= 4);
4012 }
4013 
4014 /// markAllocatedVFPs - update VFPRegs according to the alignment and
4015 /// number of VFP registers (unit is S register) requested.
4016 void ARMABIInfo::markAllocatedVFPs(unsigned Alignment,
4017                                    unsigned NumRequired) const {
4018   // Early Exit.
4019   if (AllocatedVFPs >= 16) {
4020     // We use AllocatedVFP > 16 to signal that some CPRCs were allocated on
4021     // the stack.
4022     AllocatedVFPs = 17;
4023     return;
4024   }
4025   // C.1.vfp If the argument is a VFP CPRC and there are sufficient consecutive
4026   // VFP registers of the appropriate type unallocated then the argument is
4027   // allocated to the lowest-numbered sequence of such registers.
4028   for (unsigned I = 0; I < 16; I += Alignment) {
4029     bool FoundSlot = true;
4030     for (unsigned J = I, JEnd = I + NumRequired; J < JEnd; J++)
4031       if (J >= 16 || VFPRegs[J]) {
4032          FoundSlot = false;
4033          break;
4034       }
4035     if (FoundSlot) {
4036       for (unsigned J = I, JEnd = I + NumRequired; J < JEnd; J++)
4037         VFPRegs[J] = 1;
4038       AllocatedVFPs += NumRequired;
4039       return;
4040     }
4041   }
4042   // C.2.vfp If the argument is a VFP CPRC then any VFP registers that are
4043   // unallocated are marked as unavailable.
4044   for (unsigned I = 0; I < 16; I++)
4045     VFPRegs[I] = 1;
4046   AllocatedVFPs = 17; // We do not have enough VFP registers.
4047 }
4048 
4049 /// Update AllocatedGPRs to record the number of general purpose registers
4050 /// which have been allocated. It is valid for AllocatedGPRs to go above 4,
4051 /// this represents arguments being stored on the stack.
4052 void ARMABIInfo::markAllocatedGPRs(unsigned Alignment,
4053                                           unsigned NumRequired) const {
4054   assert((Alignment == 1 || Alignment == 2) && "Alignment must be 4 or 8 bytes");
4055 
4056   if (Alignment == 2 && AllocatedGPRs & 0x1)
4057     AllocatedGPRs += 1;
4058 
4059   AllocatedGPRs += NumRequired;
4060 }
4061 
4062 void ARMABIInfo::resetAllocatedRegs(void) const {
4063   AllocatedGPRs = 0;
4064   AllocatedVFPs = 0;
4065   for (unsigned i = 0; i < NumVFPs; ++i)
4066     VFPRegs[i] = 0;
4067 }
4068 
4069 ABIArgInfo ARMABIInfo::classifyArgumentType(QualType Ty, bool isVariadic,
4070                                             bool &IsCPRC) const {
4071   // We update number of allocated VFPs according to
4072   // 6.1.2.1 The following argument types are VFP CPRCs:
4073   //   A single-precision floating-point type (including promoted
4074   //   half-precision types); A double-precision floating-point type;
4075   //   A 64-bit or 128-bit containerized vector type; Homogeneous Aggregate
4076   //   with a Base Type of a single- or double-precision floating-point type,
4077   //   64-bit containerized vectors or 128-bit containerized vectors with one
4078   //   to four Elements.
4079 
4080   // Handle illegal vector types here.
4081   if (isIllegalVectorType(Ty)) {
4082     uint64_t Size = getContext().getTypeSize(Ty);
4083     if (Size <= 32) {
4084       llvm::Type *ResType =
4085           llvm::Type::getInt32Ty(getVMContext());
4086       markAllocatedGPRs(1, 1);
4087       return ABIArgInfo::getDirect(ResType);
4088     }
4089     if (Size == 64) {
4090       llvm::Type *ResType = llvm::VectorType::get(
4091           llvm::Type::getInt32Ty(getVMContext()), 2);
4092       if (getABIKind() == ARMABIInfo::AAPCS || isVariadic){
4093         markAllocatedGPRs(2, 2);
4094       } else {
4095         markAllocatedVFPs(2, 2);
4096         IsCPRC = true;
4097       }
4098       return ABIArgInfo::getDirect(ResType);
4099     }
4100     if (Size == 128) {
4101       llvm::Type *ResType = llvm::VectorType::get(
4102           llvm::Type::getInt32Ty(getVMContext()), 4);
4103       if (getABIKind() == ARMABIInfo::AAPCS || isVariadic) {
4104         markAllocatedGPRs(2, 4);
4105       } else {
4106         markAllocatedVFPs(4, 4);
4107         IsCPRC = true;
4108       }
4109       return ABIArgInfo::getDirect(ResType);
4110     }
4111     markAllocatedGPRs(1, 1);
4112     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
4113   }
4114   // Update VFPRegs for legal vector types.
4115   if (getABIKind() == ARMABIInfo::AAPCS_VFP && !isVariadic) {
4116     if (const VectorType *VT = Ty->getAs<VectorType>()) {
4117       uint64_t Size = getContext().getTypeSize(VT);
4118       // Size of a legal vector should be power of 2 and above 64.
4119       markAllocatedVFPs(Size >= 128 ? 4 : 2, Size / 32);
4120       IsCPRC = true;
4121     }
4122   }
4123   // Update VFPRegs for floating point types.
4124   if (getABIKind() == ARMABIInfo::AAPCS_VFP && !isVariadic) {
4125     if (const BuiltinType *BT = Ty->getAs<BuiltinType>()) {
4126       if (BT->getKind() == BuiltinType::Half ||
4127           BT->getKind() == BuiltinType::Float) {
4128         markAllocatedVFPs(1, 1);
4129         IsCPRC = true;
4130       }
4131       if (BT->getKind() == BuiltinType::Double ||
4132           BT->getKind() == BuiltinType::LongDouble) {
4133         markAllocatedVFPs(2, 2);
4134         IsCPRC = true;
4135       }
4136     }
4137   }
4138 
4139   if (!isAggregateTypeForABI(Ty)) {
4140     // Treat an enum type as its underlying type.
4141     if (const EnumType *EnumTy = Ty->getAs<EnumType>()) {
4142       Ty = EnumTy->getDecl()->getIntegerType();
4143     }
4144 
4145     unsigned Size = getContext().getTypeSize(Ty);
4146     if (!IsCPRC)
4147       markAllocatedGPRs(Size > 32 ? 2 : 1, (Size + 31) / 32);
4148     return (Ty->isPromotableIntegerType() ?
4149             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
4150   }
4151 
4152   if (CGCXXABI::RecordArgABI RAA = getRecordArgABI(Ty, getCXXABI())) {
4153     markAllocatedGPRs(1, 1);
4154     return ABIArgInfo::getIndirect(0, RAA == CGCXXABI::RAA_DirectInMemory);
4155   }
4156 
4157   // Ignore empty records.
4158   if (isEmptyRecord(getContext(), Ty, true))
4159     return ABIArgInfo::getIgnore();
4160 
4161   if (getABIKind() == ARMABIInfo::AAPCS_VFP && !isVariadic) {
4162     // Homogeneous Aggregates need to be expanded when we can fit the aggregate
4163     // into VFP registers.
4164     const Type *Base = 0;
4165     uint64_t Members = 0;
4166     if (isHomogeneousAggregate(Ty, Base, getContext(), &Members)) {
4167       assert(Base && "Base class should be set for homogeneous aggregate");
4168       // Base can be a floating-point or a vector.
4169       if (Base->isVectorType()) {
4170         // ElementSize is in number of floats.
4171         unsigned ElementSize = getContext().getTypeSize(Base) == 64 ? 2 : 4;
4172         markAllocatedVFPs(ElementSize,
4173                           Members * ElementSize);
4174       } else if (Base->isSpecificBuiltinType(BuiltinType::Float))
4175         markAllocatedVFPs(1, Members);
4176       else {
4177         assert(Base->isSpecificBuiltinType(BuiltinType::Double) ||
4178                Base->isSpecificBuiltinType(BuiltinType::LongDouble));
4179         markAllocatedVFPs(2, Members * 2);
4180       }
4181       IsCPRC = true;
4182       return ABIArgInfo::getDirect();
4183     }
4184   }
4185 
4186   // Support byval for ARM.
4187   // The ABI alignment for APCS is 4-byte and for AAPCS at least 4-byte and at
4188   // most 8-byte. We realign the indirect argument if type alignment is bigger
4189   // than ABI alignment.
4190   uint64_t ABIAlign = 4;
4191   uint64_t TyAlign = getContext().getTypeAlign(Ty) / 8;
4192   if (getABIKind() == ARMABIInfo::AAPCS_VFP ||
4193       getABIKind() == ARMABIInfo::AAPCS)
4194     ABIAlign = std::min(std::max(TyAlign, (uint64_t)4), (uint64_t)8);
4195   if (getContext().getTypeSizeInChars(Ty) > CharUnits::fromQuantity(64)) {
4196     // Update Allocated GPRs
4197     markAllocatedGPRs(1, 1);
4198     return ABIArgInfo::getIndirect(TyAlign, /*ByVal=*/true,
4199            /*Realign=*/TyAlign > ABIAlign);
4200   }
4201 
4202   // Otherwise, pass by coercing to a structure of the appropriate size.
4203   llvm::Type* ElemTy;
4204   unsigned SizeRegs;
4205   // FIXME: Try to match the types of the arguments more accurately where
4206   // we can.
4207   if (getContext().getTypeAlign(Ty) <= 32) {
4208     ElemTy = llvm::Type::getInt32Ty(getVMContext());
4209     SizeRegs = (getContext().getTypeSize(Ty) + 31) / 32;
4210     markAllocatedGPRs(1, SizeRegs);
4211   } else {
4212     ElemTy = llvm::Type::getInt64Ty(getVMContext());
4213     SizeRegs = (getContext().getTypeSize(Ty) + 63) / 64;
4214     markAllocatedGPRs(2, SizeRegs * 2);
4215   }
4216 
4217   llvm::Type *STy =
4218     llvm::StructType::get(llvm::ArrayType::get(ElemTy, SizeRegs), NULL);
4219   return ABIArgInfo::getDirect(STy);
4220 }
4221 
4222 static bool isIntegerLikeType(QualType Ty, ASTContext &Context,
4223                               llvm::LLVMContext &VMContext) {
4224   // APCS, C Language Calling Conventions, Non-Simple Return Values: A structure
4225   // is called integer-like if its size is less than or equal to one word, and
4226   // the offset of each of its addressable sub-fields is zero.
4227 
4228   uint64_t Size = Context.getTypeSize(Ty);
4229 
4230   // Check that the type fits in a word.
4231   if (Size > 32)
4232     return false;
4233 
4234   // FIXME: Handle vector types!
4235   if (Ty->isVectorType())
4236     return false;
4237 
4238   // Float types are never treated as "integer like".
4239   if (Ty->isRealFloatingType())
4240     return false;
4241 
4242   // If this is a builtin or pointer type then it is ok.
4243   if (Ty->getAs<BuiltinType>() || Ty->isPointerType())
4244     return true;
4245 
4246   // Small complex integer types are "integer like".
4247   if (const ComplexType *CT = Ty->getAs<ComplexType>())
4248     return isIntegerLikeType(CT->getElementType(), Context, VMContext);
4249 
4250   // Single element and zero sized arrays should be allowed, by the definition
4251   // above, but they are not.
4252 
4253   // Otherwise, it must be a record type.
4254   const RecordType *RT = Ty->getAs<RecordType>();
4255   if (!RT) return false;
4256 
4257   // Ignore records with flexible arrays.
4258   const RecordDecl *RD = RT->getDecl();
4259   if (RD->hasFlexibleArrayMember())
4260     return false;
4261 
4262   // Check that all sub-fields are at offset 0, and are themselves "integer
4263   // like".
4264   const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
4265 
4266   bool HadField = false;
4267   unsigned idx = 0;
4268   for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
4269        i != e; ++i, ++idx) {
4270     const FieldDecl *FD = *i;
4271 
4272     // Bit-fields are not addressable, we only need to verify they are "integer
4273     // like". We still have to disallow a subsequent non-bitfield, for example:
4274     //   struct { int : 0; int x }
4275     // is non-integer like according to gcc.
4276     if (FD->isBitField()) {
4277       if (!RD->isUnion())
4278         HadField = true;
4279 
4280       if (!isIntegerLikeType(FD->getType(), Context, VMContext))
4281         return false;
4282 
4283       continue;
4284     }
4285 
4286     // Check if this field is at offset 0.
4287     if (Layout.getFieldOffset(idx) != 0)
4288       return false;
4289 
4290     if (!isIntegerLikeType(FD->getType(), Context, VMContext))
4291       return false;
4292 
4293     // Only allow at most one field in a structure. This doesn't match the
4294     // wording above, but follows gcc in situations with a field following an
4295     // empty structure.
4296     if (!RD->isUnion()) {
4297       if (HadField)
4298         return false;
4299 
4300       HadField = true;
4301     }
4302   }
4303 
4304   return true;
4305 }
4306 
4307 ABIArgInfo ARMABIInfo::classifyReturnType(QualType RetTy,
4308                                           bool isVariadic) const {
4309   if (RetTy->isVoidType())
4310     return ABIArgInfo::getIgnore();
4311 
4312   // Large vector types should be returned via memory.
4313   if (RetTy->isVectorType() && getContext().getTypeSize(RetTy) > 128) {
4314     markAllocatedGPRs(1, 1);
4315     return ABIArgInfo::getIndirect(0);
4316   }
4317 
4318   if (!isAggregateTypeForABI(RetTy)) {
4319     // Treat an enum type as its underlying type.
4320     if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
4321       RetTy = EnumTy->getDecl()->getIntegerType();
4322 
4323     return (RetTy->isPromotableIntegerType() ?
4324             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
4325   }
4326 
4327   // Are we following APCS?
4328   if (getABIKind() == APCS) {
4329     if (isEmptyRecord(getContext(), RetTy, false))
4330       return ABIArgInfo::getIgnore();
4331 
4332     // Complex types are all returned as packed integers.
4333     //
4334     // FIXME: Consider using 2 x vector types if the back end handles them
4335     // correctly.
4336     if (RetTy->isAnyComplexType())
4337       return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),
4338                                               getContext().getTypeSize(RetTy)));
4339 
4340     // Integer like structures are returned in r0.
4341     if (isIntegerLikeType(RetTy, getContext(), getVMContext())) {
4342       // Return in the smallest viable integer type.
4343       uint64_t Size = getContext().getTypeSize(RetTy);
4344       if (Size <= 8)
4345         return ABIArgInfo::getDirect(llvm::Type::getInt8Ty(getVMContext()));
4346       if (Size <= 16)
4347         return ABIArgInfo::getDirect(llvm::Type::getInt16Ty(getVMContext()));
4348       return ABIArgInfo::getDirect(llvm::Type::getInt32Ty(getVMContext()));
4349     }
4350 
4351     // Otherwise return in memory.
4352     markAllocatedGPRs(1, 1);
4353     return ABIArgInfo::getIndirect(0);
4354   }
4355 
4356   // Otherwise this is an AAPCS variant.
4357 
4358   if (isEmptyRecord(getContext(), RetTy, true))
4359     return ABIArgInfo::getIgnore();
4360 
4361   // Check for homogeneous aggregates with AAPCS-VFP.
4362   if (getABIKind() == AAPCS_VFP && !isVariadic) {
4363     const Type *Base = 0;
4364     if (isHomogeneousAggregate(RetTy, Base, getContext())) {
4365       assert(Base && "Base class should be set for homogeneous aggregate");
4366       // Homogeneous Aggregates are returned directly.
4367       return ABIArgInfo::getDirect();
4368     }
4369   }
4370 
4371   // Aggregates <= 4 bytes are returned in r0; other aggregates
4372   // are returned indirectly.
4373   uint64_t Size = getContext().getTypeSize(RetTy);
4374   if (Size <= 32) {
4375     // Return in the smallest viable integer type.
4376     if (Size <= 8)
4377       return ABIArgInfo::getDirect(llvm::Type::getInt8Ty(getVMContext()));
4378     if (Size <= 16)
4379       return ABIArgInfo::getDirect(llvm::Type::getInt16Ty(getVMContext()));
4380     return ABIArgInfo::getDirect(llvm::Type::getInt32Ty(getVMContext()));
4381   }
4382 
4383   markAllocatedGPRs(1, 1);
4384   return ABIArgInfo::getIndirect(0);
4385 }
4386 
4387 /// isIllegalVector - check whether Ty is an illegal vector type.
4388 bool ARMABIInfo::isIllegalVectorType(QualType Ty) const {
4389   if (const VectorType *VT = Ty->getAs<VectorType>()) {
4390     // Check whether VT is legal.
4391     unsigned NumElements = VT->getNumElements();
4392     uint64_t Size = getContext().getTypeSize(VT);
4393     // NumElements should be power of 2.
4394     if ((NumElements & (NumElements - 1)) != 0)
4395       return true;
4396     // Size should be greater than 32 bits.
4397     return Size <= 32;
4398   }
4399   return false;
4400 }
4401 
4402 llvm::Value *ARMABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
4403                                    CodeGenFunction &CGF) const {
4404   llvm::Type *BP = CGF.Int8PtrTy;
4405   llvm::Type *BPP = CGF.Int8PtrPtrTy;
4406 
4407   CGBuilderTy &Builder = CGF.Builder;
4408   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP, "ap");
4409   llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
4410 
4411   if (isEmptyRecord(getContext(), Ty, true)) {
4412     // These are ignored for parameter passing purposes.
4413     llvm::Type *PTy = llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
4414     return Builder.CreateBitCast(Addr, PTy);
4415   }
4416 
4417   uint64_t Size = CGF.getContext().getTypeSize(Ty) / 8;
4418   uint64_t TyAlign = CGF.getContext().getTypeAlign(Ty) / 8;
4419   bool IsIndirect = false;
4420 
4421   // The ABI alignment for 64-bit or 128-bit vectors is 8 for AAPCS and 4 for
4422   // APCS. For AAPCS, the ABI alignment is at least 4-byte and at most 8-byte.
4423   if (getABIKind() == ARMABIInfo::AAPCS_VFP ||
4424       getABIKind() == ARMABIInfo::AAPCS)
4425     TyAlign = std::min(std::max(TyAlign, (uint64_t)4), (uint64_t)8);
4426   else
4427     TyAlign = 4;
4428   // Use indirect if size of the illegal vector is bigger than 16 bytes.
4429   if (isIllegalVectorType(Ty) && Size > 16) {
4430     IsIndirect = true;
4431     Size = 4;
4432     TyAlign = 4;
4433   }
4434 
4435   // Handle address alignment for ABI alignment > 4 bytes.
4436   if (TyAlign > 4) {
4437     assert((TyAlign & (TyAlign - 1)) == 0 &&
4438            "Alignment is not power of 2!");
4439     llvm::Value *AddrAsInt = Builder.CreatePtrToInt(Addr, CGF.Int32Ty);
4440     AddrAsInt = Builder.CreateAdd(AddrAsInt, Builder.getInt32(TyAlign - 1));
4441     AddrAsInt = Builder.CreateAnd(AddrAsInt, Builder.getInt32(~(TyAlign - 1)));
4442     Addr = Builder.CreateIntToPtr(AddrAsInt, BP, "ap.align");
4443   }
4444 
4445   uint64_t Offset =
4446     llvm::RoundUpToAlignment(Size, 4);
4447   llvm::Value *NextAddr =
4448     Builder.CreateGEP(Addr, llvm::ConstantInt::get(CGF.Int32Ty, Offset),
4449                       "ap.next");
4450   Builder.CreateStore(NextAddr, VAListAddrAsBPP);
4451 
4452   if (IsIndirect)
4453     Addr = Builder.CreateLoad(Builder.CreateBitCast(Addr, BPP));
4454   else if (TyAlign < CGF.getContext().getTypeAlign(Ty) / 8) {
4455     // We can't directly cast ap.cur to pointer to a vector type, since ap.cur
4456     // may not be correctly aligned for the vector type. We create an aligned
4457     // temporary space and copy the content over from ap.cur to the temporary
4458     // space. This is necessary if the natural alignment of the type is greater
4459     // than the ABI alignment.
4460     llvm::Type *I8PtrTy = Builder.getInt8PtrTy();
4461     CharUnits CharSize = getContext().getTypeSizeInChars(Ty);
4462     llvm::Value *AlignedTemp = CGF.CreateTempAlloca(CGF.ConvertType(Ty),
4463                                                     "var.align");
4464     llvm::Value *Dst = Builder.CreateBitCast(AlignedTemp, I8PtrTy);
4465     llvm::Value *Src = Builder.CreateBitCast(Addr, I8PtrTy);
4466     Builder.CreateMemCpy(Dst, Src,
4467         llvm::ConstantInt::get(CGF.IntPtrTy, CharSize.getQuantity()),
4468         TyAlign, false);
4469     Addr = AlignedTemp; //The content is in aligned location.
4470   }
4471   llvm::Type *PTy =
4472     llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
4473   llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy);
4474 
4475   return AddrTyped;
4476 }
4477 
4478 namespace {
4479 
4480 class NaClARMABIInfo : public ABIInfo {
4481  public:
4482   NaClARMABIInfo(CodeGen::CodeGenTypes &CGT, ARMABIInfo::ABIKind Kind)
4483       : ABIInfo(CGT), PInfo(CGT), NInfo(CGT, Kind) {}
4484   void computeInfo(CGFunctionInfo &FI) const override;
4485   llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
4486                          CodeGenFunction &CGF) const override;
4487  private:
4488   PNaClABIInfo PInfo; // Used for generating calls with pnaclcall callingconv.
4489   ARMABIInfo NInfo; // Used for everything else.
4490 };
4491 
4492 class NaClARMTargetCodeGenInfo : public TargetCodeGenInfo  {
4493  public:
4494   NaClARMTargetCodeGenInfo(CodeGen::CodeGenTypes &CGT, ARMABIInfo::ABIKind Kind)
4495       : TargetCodeGenInfo(new NaClARMABIInfo(CGT, Kind)) {}
4496 };
4497 
4498 }
4499 
4500 void NaClARMABIInfo::computeInfo(CGFunctionInfo &FI) const {
4501   if (FI.getASTCallingConvention() == CC_PnaclCall)
4502     PInfo.computeInfo(FI);
4503   else
4504     static_cast<const ABIInfo&>(NInfo).computeInfo(FI);
4505 }
4506 
4507 llvm::Value *NaClARMABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
4508                                        CodeGenFunction &CGF) const {
4509   // Always use the native convention; calling pnacl-style varargs functions
4510   // is unsupported.
4511   return static_cast<const ABIInfo&>(NInfo).EmitVAArg(VAListAddr, Ty, CGF);
4512 }
4513 
4514 //===----------------------------------------------------------------------===//
4515 // AArch64 ABI Implementation
4516 //===----------------------------------------------------------------------===//
4517 
4518 namespace {
4519 
4520 class AArch64ABIInfo : public ABIInfo {
4521 public:
4522   AArch64ABIInfo(CodeGenTypes &CGT) : ABIInfo(CGT) {}
4523 
4524 private:
4525   // The AArch64 PCS is explicit about return types and argument types being
4526   // handled identically, so we don't need to draw a distinction between
4527   // Argument and Return classification.
4528   ABIArgInfo classifyGenericType(QualType Ty, int &FreeIntRegs,
4529                                  int &FreeVFPRegs) const;
4530 
4531   ABIArgInfo tryUseRegs(QualType Ty, int &FreeRegs, int RegsNeeded, bool IsInt,
4532                         llvm::Type *DirectTy = 0) const;
4533 
4534   void computeInfo(CGFunctionInfo &FI) const override;
4535 
4536   llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
4537                          CodeGenFunction &CGF) const override;
4538 };
4539 
4540 class AArch64TargetCodeGenInfo : public TargetCodeGenInfo {
4541 public:
4542   AArch64TargetCodeGenInfo(CodeGenTypes &CGT)
4543     :TargetCodeGenInfo(new AArch64ABIInfo(CGT)) {}
4544 
4545   const AArch64ABIInfo &getABIInfo() const {
4546     return static_cast<const AArch64ABIInfo&>(TargetCodeGenInfo::getABIInfo());
4547   }
4548 
4549   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const override {
4550     return 31;
4551   }
4552 
4553   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
4554                                llvm::Value *Address) const override {
4555     // 0-31 are x0-x30 and sp: 8 bytes each
4556     llvm::Value *Eight8 = llvm::ConstantInt::get(CGF.Int8Ty, 8);
4557     AssignToArrayRange(CGF.Builder, Address, Eight8, 0, 31);
4558 
4559     // 64-95 are v0-v31: 16 bytes each
4560     llvm::Value *Sixteen8 = llvm::ConstantInt::get(CGF.Int8Ty, 16);
4561     AssignToArrayRange(CGF.Builder, Address, Sixteen8, 64, 95);
4562 
4563     return false;
4564   }
4565 
4566 };
4567 
4568 }
4569 
4570 void AArch64ABIInfo::computeInfo(CGFunctionInfo &FI) const {
4571   int FreeIntRegs = 8, FreeVFPRegs = 8;
4572 
4573   FI.getReturnInfo() = classifyGenericType(FI.getReturnType(),
4574                                            FreeIntRegs, FreeVFPRegs);
4575 
4576   FreeIntRegs = FreeVFPRegs = 8;
4577   for (auto &I : FI.arguments()) {
4578     I.info = classifyGenericType(I.type, FreeIntRegs, FreeVFPRegs);
4579 
4580   }
4581 }
4582 
4583 ABIArgInfo
4584 AArch64ABIInfo::tryUseRegs(QualType Ty, int &FreeRegs, int RegsNeeded,
4585                            bool IsInt, llvm::Type *DirectTy) const {
4586   if (FreeRegs >= RegsNeeded) {
4587     FreeRegs -= RegsNeeded;
4588     return ABIArgInfo::getDirect(DirectTy);
4589   }
4590 
4591   llvm::Type *Padding = 0;
4592 
4593   // We need padding so that later arguments don't get filled in anyway. That
4594   // wouldn't happen if only ByVal arguments followed in the same category, but
4595   // a large structure will simply seem to be a pointer as far as LLVM is
4596   // concerned.
4597   if (FreeRegs > 0) {
4598     if (IsInt)
4599       Padding = llvm::Type::getInt64Ty(getVMContext());
4600     else
4601       Padding = llvm::Type::getFloatTy(getVMContext());
4602 
4603     // Either [N x i64] or [N x float].
4604     Padding = llvm::ArrayType::get(Padding, FreeRegs);
4605     FreeRegs = 0;
4606   }
4607 
4608   return ABIArgInfo::getIndirect(getContext().getTypeAlign(Ty) / 8,
4609                                  /*IsByVal=*/ true, /*Realign=*/ false,
4610                                  Padding);
4611 }
4612 
4613 
4614 ABIArgInfo AArch64ABIInfo::classifyGenericType(QualType Ty,
4615                                                int &FreeIntRegs,
4616                                                int &FreeVFPRegs) const {
4617   // Can only occurs for return, but harmless otherwise.
4618   if (Ty->isVoidType())
4619     return ABIArgInfo::getIgnore();
4620 
4621   // Large vector types should be returned via memory. There's no such concept
4622   // in the ABI, but they'd be over 16 bytes anyway so no matter how they're
4623   // classified they'd go into memory (see B.3).
4624   if (Ty->isVectorType() && getContext().getTypeSize(Ty) > 128) {
4625     if (FreeIntRegs > 0)
4626       --FreeIntRegs;
4627     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
4628   }
4629 
4630   // All non-aggregate LLVM types have a concrete ABI representation so they can
4631   // be passed directly. After this block we're guaranteed to be in a
4632   // complicated case.
4633   if (!isAggregateTypeForABI(Ty)) {
4634     // Treat an enum type as its underlying type.
4635     if (const EnumType *EnumTy = Ty->getAs<EnumType>())
4636       Ty = EnumTy->getDecl()->getIntegerType();
4637 
4638     if (Ty->isFloatingType() || Ty->isVectorType())
4639       return tryUseRegs(Ty, FreeVFPRegs, /*RegsNeeded=*/ 1, /*IsInt=*/ false);
4640 
4641     assert(getContext().getTypeSize(Ty) <= 128 &&
4642            "unexpectedly large scalar type");
4643 
4644     int RegsNeeded = getContext().getTypeSize(Ty) > 64 ? 2 : 1;
4645 
4646     // If the type may need padding registers to ensure "alignment", we must be
4647     // careful when this is accounted for. Increasing the effective size covers
4648     // all cases.
4649     if (getContext().getTypeAlign(Ty) == 128)
4650       RegsNeeded += FreeIntRegs % 2 != 0;
4651 
4652     return tryUseRegs(Ty, FreeIntRegs, RegsNeeded, /*IsInt=*/ true);
4653   }
4654 
4655   if (CGCXXABI::RecordArgABI RAA = getRecordArgABI(Ty, getCXXABI())) {
4656     if (FreeIntRegs > 0 && RAA == CGCXXABI::RAA_Indirect)
4657       --FreeIntRegs;
4658     return ABIArgInfo::getIndirect(0, RAA == CGCXXABI::RAA_DirectInMemory);
4659   }
4660 
4661   if (isEmptyRecord(getContext(), Ty, true)) {
4662     if (!getContext().getLangOpts().CPlusPlus) {
4663       // Empty structs outside C++ mode are a GNU extension, so no ABI can
4664       // possibly tell us what to do. It turns out (I believe) that GCC ignores
4665       // the object for parameter-passsing purposes.
4666       return ABIArgInfo::getIgnore();
4667     }
4668 
4669     // The combination of C++98 9p5 (sizeof(struct) != 0) and the pseudocode
4670     // description of va_arg in the PCS require that an empty struct does
4671     // actually occupy space for parameter-passing. I'm hoping for a
4672     // clarification giving an explicit paragraph to point to in future.
4673     return tryUseRegs(Ty, FreeIntRegs, /*RegsNeeded=*/ 1, /*IsInt=*/ true,
4674                       llvm::Type::getInt8Ty(getVMContext()));
4675   }
4676 
4677   // Homogeneous vector aggregates get passed in registers or on the stack.
4678   const Type *Base = 0;
4679   uint64_t NumMembers = 0;
4680   if (isHomogeneousAggregate(Ty, Base, getContext(), &NumMembers)) {
4681     assert(Base && "Base class should be set for homogeneous aggregate");
4682     // Homogeneous aggregates are passed and returned directly.
4683     return tryUseRegs(Ty, FreeVFPRegs, /*RegsNeeded=*/ NumMembers,
4684                       /*IsInt=*/ false);
4685   }
4686 
4687   uint64_t Size = getContext().getTypeSize(Ty);
4688   if (Size <= 128) {
4689     // Small structs can use the same direct type whether they're in registers
4690     // or on the stack.
4691     llvm::Type *BaseTy;
4692     unsigned NumBases;
4693     int SizeInRegs = (Size + 63) / 64;
4694 
4695     if (getContext().getTypeAlign(Ty) == 128) {
4696       BaseTy = llvm::Type::getIntNTy(getVMContext(), 128);
4697       NumBases = 1;
4698 
4699       // If the type may need padding registers to ensure "alignment", we must
4700       // be careful when this is accounted for. Increasing the effective size
4701       // covers all cases.
4702       SizeInRegs += FreeIntRegs % 2 != 0;
4703     } else {
4704       BaseTy = llvm::Type::getInt64Ty(getVMContext());
4705       NumBases = SizeInRegs;
4706     }
4707     llvm::Type *DirectTy = llvm::ArrayType::get(BaseTy, NumBases);
4708 
4709     return tryUseRegs(Ty, FreeIntRegs, /*RegsNeeded=*/ SizeInRegs,
4710                       /*IsInt=*/ true, DirectTy);
4711   }
4712 
4713   // If the aggregate is > 16 bytes, it's passed and returned indirectly. In
4714   // LLVM terms the return uses an "sret" pointer, but that's handled elsewhere.
4715   --FreeIntRegs;
4716   return ABIArgInfo::getIndirect(0, /* byVal = */ false);
4717 }
4718 
4719 llvm::Value *AArch64ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
4720                                        CodeGenFunction &CGF) const {
4721   int FreeIntRegs = 8, FreeVFPRegs = 8;
4722   Ty = CGF.getContext().getCanonicalType(Ty);
4723   ABIArgInfo AI = classifyGenericType(Ty, FreeIntRegs, FreeVFPRegs);
4724 
4725   return EmitAArch64VAArg(VAListAddr, Ty, 8 - FreeIntRegs, 8 - FreeVFPRegs,
4726                           AI.isIndirect(), CGF);
4727 }
4728 
4729 //===----------------------------------------------------------------------===//
4730 // NVPTX ABI Implementation
4731 //===----------------------------------------------------------------------===//
4732 
4733 namespace {
4734 
4735 class NVPTXABIInfo : public ABIInfo {
4736 public:
4737   NVPTXABIInfo(CodeGenTypes &CGT) : ABIInfo(CGT) {}
4738 
4739   ABIArgInfo classifyReturnType(QualType RetTy) const;
4740   ABIArgInfo classifyArgumentType(QualType Ty) const;
4741 
4742   void computeInfo(CGFunctionInfo &FI) const override;
4743   llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
4744                          CodeGenFunction &CFG) const override;
4745 };
4746 
4747 class NVPTXTargetCodeGenInfo : public TargetCodeGenInfo {
4748 public:
4749   NVPTXTargetCodeGenInfo(CodeGenTypes &CGT)
4750     : TargetCodeGenInfo(new NVPTXABIInfo(CGT)) {}
4751 
4752   void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
4753                            CodeGen::CodeGenModule &M) const override;
4754 private:
4755   // Adds a NamedMDNode with F, Name, and Operand as operands, and adds the
4756   // resulting MDNode to the nvvm.annotations MDNode.
4757   static void addNVVMMetadata(llvm::Function *F, StringRef Name, int Operand);
4758 };
4759 
4760 ABIArgInfo NVPTXABIInfo::classifyReturnType(QualType RetTy) const {
4761   if (RetTy->isVoidType())
4762     return ABIArgInfo::getIgnore();
4763 
4764   // note: this is different from default ABI
4765   if (!RetTy->isScalarType())
4766     return ABIArgInfo::getDirect();
4767 
4768   // Treat an enum type as its underlying type.
4769   if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
4770     RetTy = EnumTy->getDecl()->getIntegerType();
4771 
4772   return (RetTy->isPromotableIntegerType() ?
4773           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
4774 }
4775 
4776 ABIArgInfo NVPTXABIInfo::classifyArgumentType(QualType Ty) const {
4777   // Treat an enum type as its underlying type.
4778   if (const EnumType *EnumTy = Ty->getAs<EnumType>())
4779     Ty = EnumTy->getDecl()->getIntegerType();
4780 
4781   return (Ty->isPromotableIntegerType() ?
4782           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
4783 }
4784 
4785 void NVPTXABIInfo::computeInfo(CGFunctionInfo &FI) const {
4786   if (!getCXXABI().classifyReturnType(FI))
4787     FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
4788   for (auto &I : FI.arguments())
4789     I.info = classifyArgumentType(I.type);
4790 
4791   // Always honor user-specified calling convention.
4792   if (FI.getCallingConvention() != llvm::CallingConv::C)
4793     return;
4794 
4795   FI.setEffectiveCallingConvention(getRuntimeCC());
4796 }
4797 
4798 llvm::Value *NVPTXABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
4799                                      CodeGenFunction &CFG) const {
4800   llvm_unreachable("NVPTX does not support varargs");
4801 }
4802 
4803 void NVPTXTargetCodeGenInfo::
4804 SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
4805                     CodeGen::CodeGenModule &M) const{
4806   const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
4807   if (!FD) return;
4808 
4809   llvm::Function *F = cast<llvm::Function>(GV);
4810 
4811   // Perform special handling in OpenCL mode
4812   if (M.getLangOpts().OpenCL) {
4813     // Use OpenCL function attributes to check for kernel functions
4814     // By default, all functions are device functions
4815     if (FD->hasAttr<OpenCLKernelAttr>()) {
4816       // OpenCL __kernel functions get kernel metadata
4817       // Create !{<func-ref>, metadata !"kernel", i32 1} node
4818       addNVVMMetadata(F, "kernel", 1);
4819       // And kernel functions are not subject to inlining
4820       F->addFnAttr(llvm::Attribute::NoInline);
4821     }
4822   }
4823 
4824   // Perform special handling in CUDA mode.
4825   if (M.getLangOpts().CUDA) {
4826     // CUDA __global__ functions get a kernel metadata entry.  Since
4827     // __global__ functions cannot be called from the device, we do not
4828     // need to set the noinline attribute.
4829     if (FD->hasAttr<CUDAGlobalAttr>()) {
4830       // Create !{<func-ref>, metadata !"kernel", i32 1} node
4831       addNVVMMetadata(F, "kernel", 1);
4832     }
4833     if (FD->hasAttr<CUDALaunchBoundsAttr>()) {
4834       // Create !{<func-ref>, metadata !"maxntidx", i32 <val>} node
4835       addNVVMMetadata(F, "maxntidx",
4836                       FD->getAttr<CUDALaunchBoundsAttr>()->getMaxThreads());
4837       // min blocks is a default argument for CUDALaunchBoundsAttr, so getting a
4838       // zero value from getMinBlocks either means it was not specified in
4839       // __launch_bounds__ or the user specified a 0 value. In both cases, we
4840       // don't have to add a PTX directive.
4841       int MinCTASM = FD->getAttr<CUDALaunchBoundsAttr>()->getMinBlocks();
4842       if (MinCTASM > 0) {
4843         // Create !{<func-ref>, metadata !"minctasm", i32 <val>} node
4844         addNVVMMetadata(F, "minctasm", MinCTASM);
4845       }
4846     }
4847   }
4848 }
4849 
4850 void NVPTXTargetCodeGenInfo::addNVVMMetadata(llvm::Function *F, StringRef Name,
4851                                              int Operand) {
4852   llvm::Module *M = F->getParent();
4853   llvm::LLVMContext &Ctx = M->getContext();
4854 
4855   // Get "nvvm.annotations" metadata node
4856   llvm::NamedMDNode *MD = M->getOrInsertNamedMetadata("nvvm.annotations");
4857 
4858   llvm::Value *MDVals[] = {
4859       F, llvm::MDString::get(Ctx, Name),
4860       llvm::ConstantInt::get(llvm::Type::getInt32Ty(Ctx), Operand)};
4861   // Append metadata to nvvm.annotations
4862   MD->addOperand(llvm::MDNode::get(Ctx, MDVals));
4863 }
4864 }
4865 
4866 //===----------------------------------------------------------------------===//
4867 // SystemZ ABI Implementation
4868 //===----------------------------------------------------------------------===//
4869 
4870 namespace {
4871 
4872 class SystemZABIInfo : public ABIInfo {
4873 public:
4874   SystemZABIInfo(CodeGenTypes &CGT) : ABIInfo(CGT) {}
4875 
4876   bool isPromotableIntegerType(QualType Ty) const;
4877   bool isCompoundType(QualType Ty) const;
4878   bool isFPArgumentType(QualType Ty) const;
4879 
4880   ABIArgInfo classifyReturnType(QualType RetTy) const;
4881   ABIArgInfo classifyArgumentType(QualType ArgTy) const;
4882 
4883   void computeInfo(CGFunctionInfo &FI) const override {
4884     if (!getCXXABI().classifyReturnType(FI))
4885       FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
4886     for (auto &I : FI.arguments())
4887       I.info = classifyArgumentType(I.type);
4888   }
4889 
4890   llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
4891                          CodeGenFunction &CGF) const override;
4892 };
4893 
4894 class SystemZTargetCodeGenInfo : public TargetCodeGenInfo {
4895 public:
4896   SystemZTargetCodeGenInfo(CodeGenTypes &CGT)
4897     : TargetCodeGenInfo(new SystemZABIInfo(CGT)) {}
4898 };
4899 
4900 }
4901 
4902 bool SystemZABIInfo::isPromotableIntegerType(QualType Ty) const {
4903   // Treat an enum type as its underlying type.
4904   if (const EnumType *EnumTy = Ty->getAs<EnumType>())
4905     Ty = EnumTy->getDecl()->getIntegerType();
4906 
4907   // Promotable integer types are required to be promoted by the ABI.
4908   if (Ty->isPromotableIntegerType())
4909     return true;
4910 
4911   // 32-bit values must also be promoted.
4912   if (const BuiltinType *BT = Ty->getAs<BuiltinType>())
4913     switch (BT->getKind()) {
4914     case BuiltinType::Int:
4915     case BuiltinType::UInt:
4916       return true;
4917     default:
4918       return false;
4919     }
4920   return false;
4921 }
4922 
4923 bool SystemZABIInfo::isCompoundType(QualType Ty) const {
4924   return Ty->isAnyComplexType() || isAggregateTypeForABI(Ty);
4925 }
4926 
4927 bool SystemZABIInfo::isFPArgumentType(QualType Ty) const {
4928   if (const BuiltinType *BT = Ty->getAs<BuiltinType>())
4929     switch (BT->getKind()) {
4930     case BuiltinType::Float:
4931     case BuiltinType::Double:
4932       return true;
4933     default:
4934       return false;
4935     }
4936 
4937   if (const RecordType *RT = Ty->getAsStructureType()) {
4938     const RecordDecl *RD = RT->getDecl();
4939     bool Found = false;
4940 
4941     // If this is a C++ record, check the bases first.
4942     if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD))
4943       for (const auto &I : CXXRD->bases()) {
4944         QualType Base = I.getType();
4945 
4946         // Empty bases don't affect things either way.
4947         if (isEmptyRecord(getContext(), Base, true))
4948           continue;
4949 
4950         if (Found)
4951           return false;
4952         Found = isFPArgumentType(Base);
4953         if (!Found)
4954           return false;
4955       }
4956 
4957     // Check the fields.
4958     for (const auto *FD : RD->fields()) {
4959       // Empty bitfields don't affect things either way.
4960       // Unlike isSingleElementStruct(), empty structure and array fields
4961       // do count.  So do anonymous bitfields that aren't zero-sized.
4962       if (FD->isBitField() && FD->getBitWidthValue(getContext()) == 0)
4963         return true;
4964 
4965       // Unlike isSingleElementStruct(), arrays do not count.
4966       // Nested isFPArgumentType structures still do though.
4967       if (Found)
4968         return false;
4969       Found = isFPArgumentType(FD->getType());
4970       if (!Found)
4971         return false;
4972     }
4973 
4974     // Unlike isSingleElementStruct(), trailing padding is allowed.
4975     // An 8-byte aligned struct s { float f; } is passed as a double.
4976     return Found;
4977   }
4978 
4979   return false;
4980 }
4981 
4982 llvm::Value *SystemZABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
4983                                        CodeGenFunction &CGF) const {
4984   // Assume that va_list type is correct; should be pointer to LLVM type:
4985   // struct {
4986   //   i64 __gpr;
4987   //   i64 __fpr;
4988   //   i8 *__overflow_arg_area;
4989   //   i8 *__reg_save_area;
4990   // };
4991 
4992   // Every argument occupies 8 bytes and is passed by preference in either
4993   // GPRs or FPRs.
4994   Ty = CGF.getContext().getCanonicalType(Ty);
4995   ABIArgInfo AI = classifyArgumentType(Ty);
4996   bool InFPRs = isFPArgumentType(Ty);
4997 
4998   llvm::Type *APTy = llvm::PointerType::getUnqual(CGF.ConvertTypeForMem(Ty));
4999   bool IsIndirect = AI.isIndirect();
5000   unsigned UnpaddedBitSize;
5001   if (IsIndirect) {
5002     APTy = llvm::PointerType::getUnqual(APTy);
5003     UnpaddedBitSize = 64;
5004   } else
5005     UnpaddedBitSize = getContext().getTypeSize(Ty);
5006   unsigned PaddedBitSize = 64;
5007   assert((UnpaddedBitSize <= PaddedBitSize) && "Invalid argument size.");
5008 
5009   unsigned PaddedSize = PaddedBitSize / 8;
5010   unsigned Padding = (PaddedBitSize - UnpaddedBitSize) / 8;
5011 
5012   unsigned MaxRegs, RegCountField, RegSaveIndex, RegPadding;
5013   if (InFPRs) {
5014     MaxRegs = 4; // Maximum of 4 FPR arguments
5015     RegCountField = 1; // __fpr
5016     RegSaveIndex = 16; // save offset for f0
5017     RegPadding = 0; // floats are passed in the high bits of an FPR
5018   } else {
5019     MaxRegs = 5; // Maximum of 5 GPR arguments
5020     RegCountField = 0; // __gpr
5021     RegSaveIndex = 2; // save offset for r2
5022     RegPadding = Padding; // values are passed in the low bits of a GPR
5023   }
5024 
5025   llvm::Value *RegCountPtr =
5026     CGF.Builder.CreateStructGEP(VAListAddr, RegCountField, "reg_count_ptr");
5027   llvm::Value *RegCount = CGF.Builder.CreateLoad(RegCountPtr, "reg_count");
5028   llvm::Type *IndexTy = RegCount->getType();
5029   llvm::Value *MaxRegsV = llvm::ConstantInt::get(IndexTy, MaxRegs);
5030   llvm::Value *InRegs = CGF.Builder.CreateICmpULT(RegCount, MaxRegsV,
5031                                                  "fits_in_regs");
5032 
5033   llvm::BasicBlock *InRegBlock = CGF.createBasicBlock("vaarg.in_reg");
5034   llvm::BasicBlock *InMemBlock = CGF.createBasicBlock("vaarg.in_mem");
5035   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("vaarg.end");
5036   CGF.Builder.CreateCondBr(InRegs, InRegBlock, InMemBlock);
5037 
5038   // Emit code to load the value if it was passed in registers.
5039   CGF.EmitBlock(InRegBlock);
5040 
5041   // Work out the address of an argument register.
5042   llvm::Value *PaddedSizeV = llvm::ConstantInt::get(IndexTy, PaddedSize);
5043   llvm::Value *ScaledRegCount =
5044     CGF.Builder.CreateMul(RegCount, PaddedSizeV, "scaled_reg_count");
5045   llvm::Value *RegBase =
5046     llvm::ConstantInt::get(IndexTy, RegSaveIndex * PaddedSize + RegPadding);
5047   llvm::Value *RegOffset =
5048     CGF.Builder.CreateAdd(ScaledRegCount, RegBase, "reg_offset");
5049   llvm::Value *RegSaveAreaPtr =
5050     CGF.Builder.CreateStructGEP(VAListAddr, 3, "reg_save_area_ptr");
5051   llvm::Value *RegSaveArea =
5052     CGF.Builder.CreateLoad(RegSaveAreaPtr, "reg_save_area");
5053   llvm::Value *RawRegAddr =
5054     CGF.Builder.CreateGEP(RegSaveArea, RegOffset, "raw_reg_addr");
5055   llvm::Value *RegAddr =
5056     CGF.Builder.CreateBitCast(RawRegAddr, APTy, "reg_addr");
5057 
5058   // Update the register count
5059   llvm::Value *One = llvm::ConstantInt::get(IndexTy, 1);
5060   llvm::Value *NewRegCount =
5061     CGF.Builder.CreateAdd(RegCount, One, "reg_count");
5062   CGF.Builder.CreateStore(NewRegCount, RegCountPtr);
5063   CGF.EmitBranch(ContBlock);
5064 
5065   // Emit code to load the value if it was passed in memory.
5066   CGF.EmitBlock(InMemBlock);
5067 
5068   // Work out the address of a stack argument.
5069   llvm::Value *OverflowArgAreaPtr =
5070     CGF.Builder.CreateStructGEP(VAListAddr, 2, "overflow_arg_area_ptr");
5071   llvm::Value *OverflowArgArea =
5072     CGF.Builder.CreateLoad(OverflowArgAreaPtr, "overflow_arg_area");
5073   llvm::Value *PaddingV = llvm::ConstantInt::get(IndexTy, Padding);
5074   llvm::Value *RawMemAddr =
5075     CGF.Builder.CreateGEP(OverflowArgArea, PaddingV, "raw_mem_addr");
5076   llvm::Value *MemAddr =
5077     CGF.Builder.CreateBitCast(RawMemAddr, APTy, "mem_addr");
5078 
5079   // Update overflow_arg_area_ptr pointer
5080   llvm::Value *NewOverflowArgArea =
5081     CGF.Builder.CreateGEP(OverflowArgArea, PaddedSizeV, "overflow_arg_area");
5082   CGF.Builder.CreateStore(NewOverflowArgArea, OverflowArgAreaPtr);
5083   CGF.EmitBranch(ContBlock);
5084 
5085   // Return the appropriate result.
5086   CGF.EmitBlock(ContBlock);
5087   llvm::PHINode *ResAddr = CGF.Builder.CreatePHI(APTy, 2, "va_arg.addr");
5088   ResAddr->addIncoming(RegAddr, InRegBlock);
5089   ResAddr->addIncoming(MemAddr, InMemBlock);
5090 
5091   if (IsIndirect)
5092     return CGF.Builder.CreateLoad(ResAddr, "indirect_arg");
5093 
5094   return ResAddr;
5095 }
5096 
5097 bool X86_32TargetCodeGenInfo::isStructReturnInRegABI(
5098     const llvm::Triple &Triple, const CodeGenOptions &Opts) {
5099   assert(Triple.getArch() == llvm::Triple::x86);
5100 
5101   switch (Opts.getStructReturnConvention()) {
5102   case CodeGenOptions::SRCK_Default:
5103     break;
5104   case CodeGenOptions::SRCK_OnStack:  // -fpcc-struct-return
5105     return false;
5106   case CodeGenOptions::SRCK_InRegs:  // -freg-struct-return
5107     return true;
5108   }
5109 
5110   if (Triple.isOSDarwin())
5111     return true;
5112 
5113   switch (Triple.getOS()) {
5114   case llvm::Triple::AuroraUX:
5115   case llvm::Triple::DragonFly:
5116   case llvm::Triple::FreeBSD:
5117   case llvm::Triple::OpenBSD:
5118   case llvm::Triple::Bitrig:
5119     return true;
5120   case llvm::Triple::Win32:
5121     switch (Triple.getEnvironment()) {
5122     case llvm::Triple::UnknownEnvironment:
5123     case llvm::Triple::Cygnus:
5124     case llvm::Triple::GNU:
5125     case llvm::Triple::MSVC:
5126       return true;
5127     default:
5128       return false;
5129     }
5130   default:
5131     return false;
5132   }
5133 }
5134 
5135 ABIArgInfo SystemZABIInfo::classifyReturnType(QualType RetTy) const {
5136   if (RetTy->isVoidType())
5137     return ABIArgInfo::getIgnore();
5138   if (isCompoundType(RetTy) || getContext().getTypeSize(RetTy) > 64)
5139     return ABIArgInfo::getIndirect(0);
5140   return (isPromotableIntegerType(RetTy) ?
5141           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
5142 }
5143 
5144 ABIArgInfo SystemZABIInfo::classifyArgumentType(QualType Ty) const {
5145   // Handle the generic C++ ABI.
5146   if (CGCXXABI::RecordArgABI RAA = getRecordArgABI(Ty, getCXXABI()))
5147     return ABIArgInfo::getIndirect(0, RAA == CGCXXABI::RAA_DirectInMemory);
5148 
5149   // Integers and enums are extended to full register width.
5150   if (isPromotableIntegerType(Ty))
5151     return ABIArgInfo::getExtend();
5152 
5153   // Values that are not 1, 2, 4 or 8 bytes in size are passed indirectly.
5154   uint64_t Size = getContext().getTypeSize(Ty);
5155   if (Size != 8 && Size != 16 && Size != 32 && Size != 64)
5156     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
5157 
5158   // Handle small structures.
5159   if (const RecordType *RT = Ty->getAs<RecordType>()) {
5160     // Structures with flexible arrays have variable length, so really
5161     // fail the size test above.
5162     const RecordDecl *RD = RT->getDecl();
5163     if (RD->hasFlexibleArrayMember())
5164       return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
5165 
5166     // The structure is passed as an unextended integer, a float, or a double.
5167     llvm::Type *PassTy;
5168     if (isFPArgumentType(Ty)) {
5169       assert(Size == 32 || Size == 64);
5170       if (Size == 32)
5171         PassTy = llvm::Type::getFloatTy(getVMContext());
5172       else
5173         PassTy = llvm::Type::getDoubleTy(getVMContext());
5174     } else
5175       PassTy = llvm::IntegerType::get(getVMContext(), Size);
5176     return ABIArgInfo::getDirect(PassTy);
5177   }
5178 
5179   // Non-structure compounds are passed indirectly.
5180   if (isCompoundType(Ty))
5181     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
5182 
5183   return ABIArgInfo::getDirect(0);
5184 }
5185 
5186 //===----------------------------------------------------------------------===//
5187 // MSP430 ABI Implementation
5188 //===----------------------------------------------------------------------===//
5189 
5190 namespace {
5191 
5192 class MSP430TargetCodeGenInfo : public TargetCodeGenInfo {
5193 public:
5194   MSP430TargetCodeGenInfo(CodeGenTypes &CGT)
5195     : TargetCodeGenInfo(new DefaultABIInfo(CGT)) {}
5196   void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
5197                            CodeGen::CodeGenModule &M) const override;
5198 };
5199 
5200 }
5201 
5202 void MSP430TargetCodeGenInfo::SetTargetAttributes(const Decl *D,
5203                                                   llvm::GlobalValue *GV,
5204                                              CodeGen::CodeGenModule &M) const {
5205   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
5206     if (const MSP430InterruptAttr *attr = FD->getAttr<MSP430InterruptAttr>()) {
5207       // Handle 'interrupt' attribute:
5208       llvm::Function *F = cast<llvm::Function>(GV);
5209 
5210       // Step 1: Set ISR calling convention.
5211       F->setCallingConv(llvm::CallingConv::MSP430_INTR);
5212 
5213       // Step 2: Add attributes goodness.
5214       F->addFnAttr(llvm::Attribute::NoInline);
5215 
5216       // Step 3: Emit ISR vector alias.
5217       unsigned Num = attr->getNumber() / 2;
5218       llvm::GlobalAlias::create(llvm::Function::ExternalLinkage,
5219                                 "__isr_" + Twine(Num), F);
5220     }
5221   }
5222 }
5223 
5224 //===----------------------------------------------------------------------===//
5225 // MIPS ABI Implementation.  This works for both little-endian and
5226 // big-endian variants.
5227 //===----------------------------------------------------------------------===//
5228 
5229 namespace {
5230 class MipsABIInfo : public ABIInfo {
5231   bool IsO32;
5232   unsigned MinABIStackAlignInBytes, StackAlignInBytes;
5233   void CoerceToIntArgs(uint64_t TySize,
5234                        SmallVectorImpl<llvm::Type *> &ArgList) const;
5235   llvm::Type* HandleAggregates(QualType Ty, uint64_t TySize) const;
5236   llvm::Type* returnAggregateInRegs(QualType RetTy, uint64_t Size) const;
5237   llvm::Type* getPaddingType(uint64_t Align, uint64_t Offset) const;
5238 public:
5239   MipsABIInfo(CodeGenTypes &CGT, bool _IsO32) :
5240     ABIInfo(CGT), IsO32(_IsO32), MinABIStackAlignInBytes(IsO32 ? 4 : 8),
5241     StackAlignInBytes(IsO32 ? 8 : 16) {}
5242 
5243   ABIArgInfo classifyReturnType(QualType RetTy) const;
5244   ABIArgInfo classifyArgumentType(QualType RetTy, uint64_t &Offset) const;
5245   void computeInfo(CGFunctionInfo &FI) const override;
5246   llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
5247                          CodeGenFunction &CGF) const override;
5248 };
5249 
5250 class MIPSTargetCodeGenInfo : public TargetCodeGenInfo {
5251   unsigned SizeOfUnwindException;
5252 public:
5253   MIPSTargetCodeGenInfo(CodeGenTypes &CGT, bool IsO32)
5254     : TargetCodeGenInfo(new MipsABIInfo(CGT, IsO32)),
5255       SizeOfUnwindException(IsO32 ? 24 : 32) {}
5256 
5257   int getDwarfEHStackPointer(CodeGen::CodeGenModule &CGM) const override {
5258     return 29;
5259   }
5260 
5261   void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
5262                            CodeGen::CodeGenModule &CGM) const override {
5263     const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
5264     if (!FD) return;
5265     llvm::Function *Fn = cast<llvm::Function>(GV);
5266     if (FD->hasAttr<Mips16Attr>()) {
5267       Fn->addFnAttr("mips16");
5268     }
5269     else if (FD->hasAttr<NoMips16Attr>()) {
5270       Fn->addFnAttr("nomips16");
5271     }
5272   }
5273 
5274   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
5275                                llvm::Value *Address) const override;
5276 
5277   unsigned getSizeOfUnwindException() const override {
5278     return SizeOfUnwindException;
5279   }
5280 };
5281 }
5282 
5283 void MipsABIInfo::CoerceToIntArgs(uint64_t TySize,
5284                                   SmallVectorImpl<llvm::Type *> &ArgList) const {
5285   llvm::IntegerType *IntTy =
5286     llvm::IntegerType::get(getVMContext(), MinABIStackAlignInBytes * 8);
5287 
5288   // Add (TySize / MinABIStackAlignInBytes) args of IntTy.
5289   for (unsigned N = TySize / (MinABIStackAlignInBytes * 8); N; --N)
5290     ArgList.push_back(IntTy);
5291 
5292   // If necessary, add one more integer type to ArgList.
5293   unsigned R = TySize % (MinABIStackAlignInBytes * 8);
5294 
5295   if (R)
5296     ArgList.push_back(llvm::IntegerType::get(getVMContext(), R));
5297 }
5298 
5299 // In N32/64, an aligned double precision floating point field is passed in
5300 // a register.
5301 llvm::Type* MipsABIInfo::HandleAggregates(QualType Ty, uint64_t TySize) const {
5302   SmallVector<llvm::Type*, 8> ArgList, IntArgList;
5303 
5304   if (IsO32) {
5305     CoerceToIntArgs(TySize, ArgList);
5306     return llvm::StructType::get(getVMContext(), ArgList);
5307   }
5308 
5309   if (Ty->isComplexType())
5310     return CGT.ConvertType(Ty);
5311 
5312   const RecordType *RT = Ty->getAs<RecordType>();
5313 
5314   // Unions/vectors are passed in integer registers.
5315   if (!RT || !RT->isStructureOrClassType()) {
5316     CoerceToIntArgs(TySize, ArgList);
5317     return llvm::StructType::get(getVMContext(), ArgList);
5318   }
5319 
5320   const RecordDecl *RD = RT->getDecl();
5321   const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
5322   assert(!(TySize % 8) && "Size of structure must be multiple of 8.");
5323 
5324   uint64_t LastOffset = 0;
5325   unsigned idx = 0;
5326   llvm::IntegerType *I64 = llvm::IntegerType::get(getVMContext(), 64);
5327 
5328   // Iterate over fields in the struct/class and check if there are any aligned
5329   // double fields.
5330   for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
5331        i != e; ++i, ++idx) {
5332     const QualType Ty = i->getType();
5333     const BuiltinType *BT = Ty->getAs<BuiltinType>();
5334 
5335     if (!BT || BT->getKind() != BuiltinType::Double)
5336       continue;
5337 
5338     uint64_t Offset = Layout.getFieldOffset(idx);
5339     if (Offset % 64) // Ignore doubles that are not aligned.
5340       continue;
5341 
5342     // Add ((Offset - LastOffset) / 64) args of type i64.
5343     for (unsigned j = (Offset - LastOffset) / 64; j > 0; --j)
5344       ArgList.push_back(I64);
5345 
5346     // Add double type.
5347     ArgList.push_back(llvm::Type::getDoubleTy(getVMContext()));
5348     LastOffset = Offset + 64;
5349   }
5350 
5351   CoerceToIntArgs(TySize - LastOffset, IntArgList);
5352   ArgList.append(IntArgList.begin(), IntArgList.end());
5353 
5354   return llvm::StructType::get(getVMContext(), ArgList);
5355 }
5356 
5357 llvm::Type *MipsABIInfo::getPaddingType(uint64_t OrigOffset,
5358                                         uint64_t Offset) const {
5359   if (OrigOffset + MinABIStackAlignInBytes > Offset)
5360     return 0;
5361 
5362   return llvm::IntegerType::get(getVMContext(), (Offset - OrigOffset) * 8);
5363 }
5364 
5365 ABIArgInfo
5366 MipsABIInfo::classifyArgumentType(QualType Ty, uint64_t &Offset) const {
5367   uint64_t OrigOffset = Offset;
5368   uint64_t TySize = getContext().getTypeSize(Ty);
5369   uint64_t Align = getContext().getTypeAlign(Ty) / 8;
5370 
5371   Align = std::min(std::max(Align, (uint64_t)MinABIStackAlignInBytes),
5372                    (uint64_t)StackAlignInBytes);
5373   unsigned CurrOffset = llvm::RoundUpToAlignment(Offset, Align);
5374   Offset = CurrOffset + llvm::RoundUpToAlignment(TySize, Align * 8) / 8;
5375 
5376   if (isAggregateTypeForABI(Ty) || Ty->isVectorType()) {
5377     // Ignore empty aggregates.
5378     if (TySize == 0)
5379       return ABIArgInfo::getIgnore();
5380 
5381     if (CGCXXABI::RecordArgABI RAA = getRecordArgABI(Ty, getCXXABI())) {
5382       Offset = OrigOffset + MinABIStackAlignInBytes;
5383       return ABIArgInfo::getIndirect(0, RAA == CGCXXABI::RAA_DirectInMemory);
5384     }
5385 
5386     // If we have reached here, aggregates are passed directly by coercing to
5387     // another structure type. Padding is inserted if the offset of the
5388     // aggregate is unaligned.
5389     return ABIArgInfo::getDirect(HandleAggregates(Ty, TySize), 0,
5390                                  getPaddingType(OrigOffset, CurrOffset));
5391   }
5392 
5393   // Treat an enum type as its underlying type.
5394   if (const EnumType *EnumTy = Ty->getAs<EnumType>())
5395     Ty = EnumTy->getDecl()->getIntegerType();
5396 
5397   if (Ty->isPromotableIntegerType())
5398     return ABIArgInfo::getExtend();
5399 
5400   return ABIArgInfo::getDirect(
5401       0, 0, IsO32 ? 0 : getPaddingType(OrigOffset, CurrOffset));
5402 }
5403 
5404 llvm::Type*
5405 MipsABIInfo::returnAggregateInRegs(QualType RetTy, uint64_t Size) const {
5406   const RecordType *RT = RetTy->getAs<RecordType>();
5407   SmallVector<llvm::Type*, 8> RTList;
5408 
5409   if (RT && RT->isStructureOrClassType()) {
5410     const RecordDecl *RD = RT->getDecl();
5411     const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
5412     unsigned FieldCnt = Layout.getFieldCount();
5413 
5414     // N32/64 returns struct/classes in floating point registers if the
5415     // following conditions are met:
5416     // 1. The size of the struct/class is no larger than 128-bit.
5417     // 2. The struct/class has one or two fields all of which are floating
5418     //    point types.
5419     // 3. The offset of the first field is zero (this follows what gcc does).
5420     //
5421     // Any other composite results are returned in integer registers.
5422     //
5423     if (FieldCnt && (FieldCnt <= 2) && !Layout.getFieldOffset(0)) {
5424       RecordDecl::field_iterator b = RD->field_begin(), e = RD->field_end();
5425       for (; b != e; ++b) {
5426         const BuiltinType *BT = b->getType()->getAs<BuiltinType>();
5427 
5428         if (!BT || !BT->isFloatingPoint())
5429           break;
5430 
5431         RTList.push_back(CGT.ConvertType(b->getType()));
5432       }
5433 
5434       if (b == e)
5435         return llvm::StructType::get(getVMContext(), RTList,
5436                                      RD->hasAttr<PackedAttr>());
5437 
5438       RTList.clear();
5439     }
5440   }
5441 
5442   CoerceToIntArgs(Size, RTList);
5443   return llvm::StructType::get(getVMContext(), RTList);
5444 }
5445 
5446 ABIArgInfo MipsABIInfo::classifyReturnType(QualType RetTy) const {
5447   uint64_t Size = getContext().getTypeSize(RetTy);
5448 
5449   if (RetTy->isVoidType() || Size == 0)
5450     return ABIArgInfo::getIgnore();
5451 
5452   if (isAggregateTypeForABI(RetTy) || RetTy->isVectorType()) {
5453     if (Size <= 128) {
5454       if (RetTy->isAnyComplexType())
5455         return ABIArgInfo::getDirect();
5456 
5457       // O32 returns integer vectors in registers.
5458       if (IsO32 && RetTy->isVectorType() && !RetTy->hasFloatingRepresentation())
5459         return ABIArgInfo::getDirect(returnAggregateInRegs(RetTy, Size));
5460 
5461       if (!IsO32)
5462         return ABIArgInfo::getDirect(returnAggregateInRegs(RetTy, Size));
5463     }
5464 
5465     return ABIArgInfo::getIndirect(0);
5466   }
5467 
5468   // Treat an enum type as its underlying type.
5469   if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
5470     RetTy = EnumTy->getDecl()->getIntegerType();
5471 
5472   return (RetTy->isPromotableIntegerType() ?
5473           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
5474 }
5475 
5476 void MipsABIInfo::computeInfo(CGFunctionInfo &FI) const {
5477   ABIArgInfo &RetInfo = FI.getReturnInfo();
5478   if (!getCXXABI().classifyReturnType(FI))
5479     RetInfo = classifyReturnType(FI.getReturnType());
5480 
5481   // Check if a pointer to an aggregate is passed as a hidden argument.
5482   uint64_t Offset = RetInfo.isIndirect() ? MinABIStackAlignInBytes : 0;
5483 
5484   for (auto &I : FI.arguments())
5485     I.info = classifyArgumentType(I.type, Offset);
5486 }
5487 
5488 llvm::Value* MipsABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
5489                                     CodeGenFunction &CGF) const {
5490   llvm::Type *BP = CGF.Int8PtrTy;
5491   llvm::Type *BPP = CGF.Int8PtrPtrTy;
5492 
5493   CGBuilderTy &Builder = CGF.Builder;
5494   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP, "ap");
5495   llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
5496   int64_t TypeAlign = getContext().getTypeAlign(Ty) / 8;
5497   llvm::Type *PTy = llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
5498   llvm::Value *AddrTyped;
5499   unsigned PtrWidth = getTarget().getPointerWidth(0);
5500   llvm::IntegerType *IntTy = (PtrWidth == 32) ? CGF.Int32Ty : CGF.Int64Ty;
5501 
5502   if (TypeAlign > MinABIStackAlignInBytes) {
5503     llvm::Value *AddrAsInt = CGF.Builder.CreatePtrToInt(Addr, IntTy);
5504     llvm::Value *Inc = llvm::ConstantInt::get(IntTy, TypeAlign - 1);
5505     llvm::Value *Mask = llvm::ConstantInt::get(IntTy, -TypeAlign);
5506     llvm::Value *Add = CGF.Builder.CreateAdd(AddrAsInt, Inc);
5507     llvm::Value *And = CGF.Builder.CreateAnd(Add, Mask);
5508     AddrTyped = CGF.Builder.CreateIntToPtr(And, PTy);
5509   }
5510   else
5511     AddrTyped = Builder.CreateBitCast(Addr, PTy);
5512 
5513   llvm::Value *AlignedAddr = Builder.CreateBitCast(AddrTyped, BP);
5514   TypeAlign = std::max((unsigned)TypeAlign, MinABIStackAlignInBytes);
5515   uint64_t Offset =
5516     llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, TypeAlign);
5517   llvm::Value *NextAddr =
5518     Builder.CreateGEP(AlignedAddr, llvm::ConstantInt::get(IntTy, Offset),
5519                       "ap.next");
5520   Builder.CreateStore(NextAddr, VAListAddrAsBPP);
5521 
5522   return AddrTyped;
5523 }
5524 
5525 bool
5526 MIPSTargetCodeGenInfo::initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
5527                                                llvm::Value *Address) const {
5528   // This information comes from gcc's implementation, which seems to
5529   // as canonical as it gets.
5530 
5531   // Everything on MIPS is 4 bytes.  Double-precision FP registers
5532   // are aliased to pairs of single-precision FP registers.
5533   llvm::Value *Four8 = llvm::ConstantInt::get(CGF.Int8Ty, 4);
5534 
5535   // 0-31 are the general purpose registers, $0 - $31.
5536   // 32-63 are the floating-point registers, $f0 - $f31.
5537   // 64 and 65 are the multiply/divide registers, $hi and $lo.
5538   // 66 is the (notional, I think) register for signal-handler return.
5539   AssignToArrayRange(CGF.Builder, Address, Four8, 0, 65);
5540 
5541   // 67-74 are the floating-point status registers, $fcc0 - $fcc7.
5542   // They are one bit wide and ignored here.
5543 
5544   // 80-111 are the coprocessor 0 registers, $c0r0 - $c0r31.
5545   // (coprocessor 1 is the FP unit)
5546   // 112-143 are the coprocessor 2 registers, $c2r0 - $c2r31.
5547   // 144-175 are the coprocessor 3 registers, $c3r0 - $c3r31.
5548   // 176-181 are the DSP accumulator registers.
5549   AssignToArrayRange(CGF.Builder, Address, Four8, 80, 181);
5550   return false;
5551 }
5552 
5553 //===----------------------------------------------------------------------===//
5554 // TCE ABI Implementation (see http://tce.cs.tut.fi). Uses mostly the defaults.
5555 // Currently subclassed only to implement custom OpenCL C function attribute
5556 // handling.
5557 //===----------------------------------------------------------------------===//
5558 
5559 namespace {
5560 
5561 class TCETargetCodeGenInfo : public DefaultTargetCodeGenInfo {
5562 public:
5563   TCETargetCodeGenInfo(CodeGenTypes &CGT)
5564     : DefaultTargetCodeGenInfo(CGT) {}
5565 
5566   void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
5567                            CodeGen::CodeGenModule &M) const override;
5568 };
5569 
5570 void TCETargetCodeGenInfo::SetTargetAttributes(const Decl *D,
5571                                                llvm::GlobalValue *GV,
5572                                                CodeGen::CodeGenModule &M) const {
5573   const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
5574   if (!FD) return;
5575 
5576   llvm::Function *F = cast<llvm::Function>(GV);
5577 
5578   if (M.getLangOpts().OpenCL) {
5579     if (FD->hasAttr<OpenCLKernelAttr>()) {
5580       // OpenCL C Kernel functions are not subject to inlining
5581       F->addFnAttr(llvm::Attribute::NoInline);
5582       const ReqdWorkGroupSizeAttr *Attr = FD->getAttr<ReqdWorkGroupSizeAttr>();
5583       if (Attr) {
5584         // Convert the reqd_work_group_size() attributes to metadata.
5585         llvm::LLVMContext &Context = F->getContext();
5586         llvm::NamedMDNode *OpenCLMetadata =
5587             M.getModule().getOrInsertNamedMetadata("opencl.kernel_wg_size_info");
5588 
5589         SmallVector<llvm::Value*, 5> Operands;
5590         Operands.push_back(F);
5591 
5592         Operands.push_back(llvm::Constant::getIntegerValue(M.Int32Ty,
5593                              llvm::APInt(32, Attr->getXDim())));
5594         Operands.push_back(llvm::Constant::getIntegerValue(M.Int32Ty,
5595                              llvm::APInt(32, Attr->getYDim())));
5596         Operands.push_back(llvm::Constant::getIntegerValue(M.Int32Ty,
5597                              llvm::APInt(32, Attr->getZDim())));
5598 
5599         // Add a boolean constant operand for "required" (true) or "hint" (false)
5600         // for implementing the work_group_size_hint attr later. Currently
5601         // always true as the hint is not yet implemented.
5602         Operands.push_back(llvm::ConstantInt::getTrue(Context));
5603         OpenCLMetadata->addOperand(llvm::MDNode::get(Context, Operands));
5604       }
5605     }
5606   }
5607 }
5608 
5609 }
5610 
5611 //===----------------------------------------------------------------------===//
5612 // Hexagon ABI Implementation
5613 //===----------------------------------------------------------------------===//
5614 
5615 namespace {
5616 
5617 class HexagonABIInfo : public ABIInfo {
5618 
5619 
5620 public:
5621   HexagonABIInfo(CodeGenTypes &CGT) : ABIInfo(CGT) {}
5622 
5623 private:
5624 
5625   ABIArgInfo classifyReturnType(QualType RetTy) const;
5626   ABIArgInfo classifyArgumentType(QualType RetTy) const;
5627 
5628   void computeInfo(CGFunctionInfo &FI) const override;
5629 
5630   llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
5631                          CodeGenFunction &CGF) const override;
5632 };
5633 
5634 class HexagonTargetCodeGenInfo : public TargetCodeGenInfo {
5635 public:
5636   HexagonTargetCodeGenInfo(CodeGenTypes &CGT)
5637     :TargetCodeGenInfo(new HexagonABIInfo(CGT)) {}
5638 
5639   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const override {
5640     return 29;
5641   }
5642 };
5643 
5644 }
5645 
5646 void HexagonABIInfo::computeInfo(CGFunctionInfo &FI) const {
5647   if (!getCXXABI().classifyReturnType(FI))
5648     FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
5649   for (auto &I : FI.arguments())
5650     I.info = classifyArgumentType(I.type);
5651 }
5652 
5653 ABIArgInfo HexagonABIInfo::classifyArgumentType(QualType Ty) const {
5654   if (!isAggregateTypeForABI(Ty)) {
5655     // Treat an enum type as its underlying type.
5656     if (const EnumType *EnumTy = Ty->getAs<EnumType>())
5657       Ty = EnumTy->getDecl()->getIntegerType();
5658 
5659     return (Ty->isPromotableIntegerType() ?
5660             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
5661   }
5662 
5663   // Ignore empty records.
5664   if (isEmptyRecord(getContext(), Ty, true))
5665     return ABIArgInfo::getIgnore();
5666 
5667   if (CGCXXABI::RecordArgABI RAA = getRecordArgABI(Ty, getCXXABI()))
5668     return ABIArgInfo::getIndirect(0, RAA == CGCXXABI::RAA_DirectInMemory);
5669 
5670   uint64_t Size = getContext().getTypeSize(Ty);
5671   if (Size > 64)
5672     return ABIArgInfo::getIndirect(0, /*ByVal=*/true);
5673     // Pass in the smallest viable integer type.
5674   else if (Size > 32)
5675       return ABIArgInfo::getDirect(llvm::Type::getInt64Ty(getVMContext()));
5676   else if (Size > 16)
5677       return ABIArgInfo::getDirect(llvm::Type::getInt32Ty(getVMContext()));
5678   else if (Size > 8)
5679       return ABIArgInfo::getDirect(llvm::Type::getInt16Ty(getVMContext()));
5680   else
5681       return ABIArgInfo::getDirect(llvm::Type::getInt8Ty(getVMContext()));
5682 }
5683 
5684 ABIArgInfo HexagonABIInfo::classifyReturnType(QualType RetTy) const {
5685   if (RetTy->isVoidType())
5686     return ABIArgInfo::getIgnore();
5687 
5688   // Large vector types should be returned via memory.
5689   if (RetTy->isVectorType() && getContext().getTypeSize(RetTy) > 64)
5690     return ABIArgInfo::getIndirect(0);
5691 
5692   if (!isAggregateTypeForABI(RetTy)) {
5693     // Treat an enum type as its underlying type.
5694     if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
5695       RetTy = EnumTy->getDecl()->getIntegerType();
5696 
5697     return (RetTy->isPromotableIntegerType() ?
5698             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
5699   }
5700 
5701   if (isEmptyRecord(getContext(), RetTy, true))
5702     return ABIArgInfo::getIgnore();
5703 
5704   // Aggregates <= 8 bytes are returned in r0; other aggregates
5705   // are returned indirectly.
5706   uint64_t Size = getContext().getTypeSize(RetTy);
5707   if (Size <= 64) {
5708     // Return in the smallest viable integer type.
5709     if (Size <= 8)
5710       return ABIArgInfo::getDirect(llvm::Type::getInt8Ty(getVMContext()));
5711     if (Size <= 16)
5712       return ABIArgInfo::getDirect(llvm::Type::getInt16Ty(getVMContext()));
5713     if (Size <= 32)
5714       return ABIArgInfo::getDirect(llvm::Type::getInt32Ty(getVMContext()));
5715     return ABIArgInfo::getDirect(llvm::Type::getInt64Ty(getVMContext()));
5716   }
5717 
5718   return ABIArgInfo::getIndirect(0, /*ByVal=*/true);
5719 }
5720 
5721 llvm::Value *HexagonABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
5722                                        CodeGenFunction &CGF) const {
5723   // FIXME: Need to handle alignment
5724   llvm::Type *BPP = CGF.Int8PtrPtrTy;
5725 
5726   CGBuilderTy &Builder = CGF.Builder;
5727   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP,
5728                                                        "ap");
5729   llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
5730   llvm::Type *PTy =
5731     llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
5732   llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy);
5733 
5734   uint64_t Offset =
5735     llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, 4);
5736   llvm::Value *NextAddr =
5737     Builder.CreateGEP(Addr, llvm::ConstantInt::get(CGF.Int32Ty, Offset),
5738                       "ap.next");
5739   Builder.CreateStore(NextAddr, VAListAddrAsBPP);
5740 
5741   return AddrTyped;
5742 }
5743 
5744 
5745 //===----------------------------------------------------------------------===//
5746 // SPARC v9 ABI Implementation.
5747 // Based on the SPARC Compliance Definition version 2.4.1.
5748 //
5749 // Function arguments a mapped to a nominal "parameter array" and promoted to
5750 // registers depending on their type. Each argument occupies 8 or 16 bytes in
5751 // the array, structs larger than 16 bytes are passed indirectly.
5752 //
5753 // One case requires special care:
5754 //
5755 //   struct mixed {
5756 //     int i;
5757 //     float f;
5758 //   };
5759 //
5760 // When a struct mixed is passed by value, it only occupies 8 bytes in the
5761 // parameter array, but the int is passed in an integer register, and the float
5762 // is passed in a floating point register. This is represented as two arguments
5763 // with the LLVM IR inreg attribute:
5764 //
5765 //   declare void f(i32 inreg %i, float inreg %f)
5766 //
5767 // The code generator will only allocate 4 bytes from the parameter array for
5768 // the inreg arguments. All other arguments are allocated a multiple of 8
5769 // bytes.
5770 //
5771 namespace {
5772 class SparcV9ABIInfo : public ABIInfo {
5773 public:
5774   SparcV9ABIInfo(CodeGenTypes &CGT) : ABIInfo(CGT) {}
5775 
5776 private:
5777   ABIArgInfo classifyType(QualType RetTy, unsigned SizeLimit) const;
5778   void computeInfo(CGFunctionInfo &FI) const override;
5779   llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
5780                          CodeGenFunction &CGF) const override;
5781 
5782   // Coercion type builder for structs passed in registers. The coercion type
5783   // serves two purposes:
5784   //
5785   // 1. Pad structs to a multiple of 64 bits, so they are passed 'left-aligned'
5786   //    in registers.
5787   // 2. Expose aligned floating point elements as first-level elements, so the
5788   //    code generator knows to pass them in floating point registers.
5789   //
5790   // We also compute the InReg flag which indicates that the struct contains
5791   // aligned 32-bit floats.
5792   //
5793   struct CoerceBuilder {
5794     llvm::LLVMContext &Context;
5795     const llvm::DataLayout &DL;
5796     SmallVector<llvm::Type*, 8> Elems;
5797     uint64_t Size;
5798     bool InReg;
5799 
5800     CoerceBuilder(llvm::LLVMContext &c, const llvm::DataLayout &dl)
5801       : Context(c), DL(dl), Size(0), InReg(false) {}
5802 
5803     // Pad Elems with integers until Size is ToSize.
5804     void pad(uint64_t ToSize) {
5805       assert(ToSize >= Size && "Cannot remove elements");
5806       if (ToSize == Size)
5807         return;
5808 
5809       // Finish the current 64-bit word.
5810       uint64_t Aligned = llvm::RoundUpToAlignment(Size, 64);
5811       if (Aligned > Size && Aligned <= ToSize) {
5812         Elems.push_back(llvm::IntegerType::get(Context, Aligned - Size));
5813         Size = Aligned;
5814       }
5815 
5816       // Add whole 64-bit words.
5817       while (Size + 64 <= ToSize) {
5818         Elems.push_back(llvm::Type::getInt64Ty(Context));
5819         Size += 64;
5820       }
5821 
5822       // Final in-word padding.
5823       if (Size < ToSize) {
5824         Elems.push_back(llvm::IntegerType::get(Context, ToSize - Size));
5825         Size = ToSize;
5826       }
5827     }
5828 
5829     // Add a floating point element at Offset.
5830     void addFloat(uint64_t Offset, llvm::Type *Ty, unsigned Bits) {
5831       // Unaligned floats are treated as integers.
5832       if (Offset % Bits)
5833         return;
5834       // The InReg flag is only required if there are any floats < 64 bits.
5835       if (Bits < 64)
5836         InReg = true;
5837       pad(Offset);
5838       Elems.push_back(Ty);
5839       Size = Offset + Bits;
5840     }
5841 
5842     // Add a struct type to the coercion type, starting at Offset (in bits).
5843     void addStruct(uint64_t Offset, llvm::StructType *StrTy) {
5844       const llvm::StructLayout *Layout = DL.getStructLayout(StrTy);
5845       for (unsigned i = 0, e = StrTy->getNumElements(); i != e; ++i) {
5846         llvm::Type *ElemTy = StrTy->getElementType(i);
5847         uint64_t ElemOffset = Offset + Layout->getElementOffsetInBits(i);
5848         switch (ElemTy->getTypeID()) {
5849         case llvm::Type::StructTyID:
5850           addStruct(ElemOffset, cast<llvm::StructType>(ElemTy));
5851           break;
5852         case llvm::Type::FloatTyID:
5853           addFloat(ElemOffset, ElemTy, 32);
5854           break;
5855         case llvm::Type::DoubleTyID:
5856           addFloat(ElemOffset, ElemTy, 64);
5857           break;
5858         case llvm::Type::FP128TyID:
5859           addFloat(ElemOffset, ElemTy, 128);
5860           break;
5861         case llvm::Type::PointerTyID:
5862           if (ElemOffset % 64 == 0) {
5863             pad(ElemOffset);
5864             Elems.push_back(ElemTy);
5865             Size += 64;
5866           }
5867           break;
5868         default:
5869           break;
5870         }
5871       }
5872     }
5873 
5874     // Check if Ty is a usable substitute for the coercion type.
5875     bool isUsableType(llvm::StructType *Ty) const {
5876       if (Ty->getNumElements() != Elems.size())
5877         return false;
5878       for (unsigned i = 0, e = Elems.size(); i != e; ++i)
5879         if (Elems[i] != Ty->getElementType(i))
5880           return false;
5881       return true;
5882     }
5883 
5884     // Get the coercion type as a literal struct type.
5885     llvm::Type *getType() const {
5886       if (Elems.size() == 1)
5887         return Elems.front();
5888       else
5889         return llvm::StructType::get(Context, Elems);
5890     }
5891   };
5892 };
5893 } // end anonymous namespace
5894 
5895 ABIArgInfo
5896 SparcV9ABIInfo::classifyType(QualType Ty, unsigned SizeLimit) const {
5897   if (Ty->isVoidType())
5898     return ABIArgInfo::getIgnore();
5899 
5900   uint64_t Size = getContext().getTypeSize(Ty);
5901 
5902   // Anything too big to fit in registers is passed with an explicit indirect
5903   // pointer / sret pointer.
5904   if (Size > SizeLimit)
5905     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
5906 
5907   // Treat an enum type as its underlying type.
5908   if (const EnumType *EnumTy = Ty->getAs<EnumType>())
5909     Ty = EnumTy->getDecl()->getIntegerType();
5910 
5911   // Integer types smaller than a register are extended.
5912   if (Size < 64 && Ty->isIntegerType())
5913     return ABIArgInfo::getExtend();
5914 
5915   // Other non-aggregates go in registers.
5916   if (!isAggregateTypeForABI(Ty))
5917     return ABIArgInfo::getDirect();
5918 
5919   // If a C++ object has either a non-trivial copy constructor or a non-trivial
5920   // destructor, it is passed with an explicit indirect pointer / sret pointer.
5921   if (CGCXXABI::RecordArgABI RAA = getRecordArgABI(Ty, getCXXABI()))
5922     return ABIArgInfo::getIndirect(0, RAA == CGCXXABI::RAA_DirectInMemory);
5923 
5924   // This is a small aggregate type that should be passed in registers.
5925   // Build a coercion type from the LLVM struct type.
5926   llvm::StructType *StrTy = dyn_cast<llvm::StructType>(CGT.ConvertType(Ty));
5927   if (!StrTy)
5928     return ABIArgInfo::getDirect();
5929 
5930   CoerceBuilder CB(getVMContext(), getDataLayout());
5931   CB.addStruct(0, StrTy);
5932   CB.pad(llvm::RoundUpToAlignment(CB.DL.getTypeSizeInBits(StrTy), 64));
5933 
5934   // Try to use the original type for coercion.
5935   llvm::Type *CoerceTy = CB.isUsableType(StrTy) ? StrTy : CB.getType();
5936 
5937   if (CB.InReg)
5938     return ABIArgInfo::getDirectInReg(CoerceTy);
5939   else
5940     return ABIArgInfo::getDirect(CoerceTy);
5941 }
5942 
5943 llvm::Value *SparcV9ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
5944                                        CodeGenFunction &CGF) const {
5945   ABIArgInfo AI = classifyType(Ty, 16 * 8);
5946   llvm::Type *ArgTy = CGT.ConvertType(Ty);
5947   if (AI.canHaveCoerceToType() && !AI.getCoerceToType())
5948     AI.setCoerceToType(ArgTy);
5949 
5950   llvm::Type *BPP = CGF.Int8PtrPtrTy;
5951   CGBuilderTy &Builder = CGF.Builder;
5952   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP, "ap");
5953   llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
5954   llvm::Type *ArgPtrTy = llvm::PointerType::getUnqual(ArgTy);
5955   llvm::Value *ArgAddr;
5956   unsigned Stride;
5957 
5958   switch (AI.getKind()) {
5959   case ABIArgInfo::Expand:
5960   case ABIArgInfo::InAlloca:
5961     llvm_unreachable("Unsupported ABI kind for va_arg");
5962 
5963   case ABIArgInfo::Extend:
5964     Stride = 8;
5965     ArgAddr = Builder
5966       .CreateConstGEP1_32(Addr, 8 - getDataLayout().getTypeAllocSize(ArgTy),
5967                           "extend");
5968     break;
5969 
5970   case ABIArgInfo::Direct:
5971     Stride = getDataLayout().getTypeAllocSize(AI.getCoerceToType());
5972     ArgAddr = Addr;
5973     break;
5974 
5975   case ABIArgInfo::Indirect:
5976     Stride = 8;
5977     ArgAddr = Builder.CreateBitCast(Addr,
5978                                     llvm::PointerType::getUnqual(ArgPtrTy),
5979                                     "indirect");
5980     ArgAddr = Builder.CreateLoad(ArgAddr, "indirect.arg");
5981     break;
5982 
5983   case ABIArgInfo::Ignore:
5984     return llvm::UndefValue::get(ArgPtrTy);
5985   }
5986 
5987   // Update VAList.
5988   Addr = Builder.CreateConstGEP1_32(Addr, Stride, "ap.next");
5989   Builder.CreateStore(Addr, VAListAddrAsBPP);
5990 
5991   return Builder.CreatePointerCast(ArgAddr, ArgPtrTy, "arg.addr");
5992 }
5993 
5994 void SparcV9ABIInfo::computeInfo(CGFunctionInfo &FI) const {
5995   FI.getReturnInfo() = classifyType(FI.getReturnType(), 32 * 8);
5996   for (auto &I : FI.arguments())
5997     I.info = classifyType(I.type, 16 * 8);
5998 }
5999 
6000 namespace {
6001 class SparcV9TargetCodeGenInfo : public TargetCodeGenInfo {
6002 public:
6003   SparcV9TargetCodeGenInfo(CodeGenTypes &CGT)
6004     : TargetCodeGenInfo(new SparcV9ABIInfo(CGT)) {}
6005 
6006   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const override {
6007     return 14;
6008   }
6009 
6010   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
6011                                llvm::Value *Address) const override;
6012 };
6013 } // end anonymous namespace
6014 
6015 bool
6016 SparcV9TargetCodeGenInfo::initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
6017                                                 llvm::Value *Address) const {
6018   // This is calculated from the LLVM and GCC tables and verified
6019   // against gcc output.  AFAIK all ABIs use the same encoding.
6020 
6021   CodeGen::CGBuilderTy &Builder = CGF.Builder;
6022 
6023   llvm::IntegerType *i8 = CGF.Int8Ty;
6024   llvm::Value *Four8 = llvm::ConstantInt::get(i8, 4);
6025   llvm::Value *Eight8 = llvm::ConstantInt::get(i8, 8);
6026 
6027   // 0-31: the 8-byte general-purpose registers
6028   AssignToArrayRange(Builder, Address, Eight8, 0, 31);
6029 
6030   // 32-63: f0-31, the 4-byte floating-point registers
6031   AssignToArrayRange(Builder, Address, Four8, 32, 63);
6032 
6033   //   Y   = 64
6034   //   PSR = 65
6035   //   WIM = 66
6036   //   TBR = 67
6037   //   PC  = 68
6038   //   NPC = 69
6039   //   FSR = 70
6040   //   CSR = 71
6041   AssignToArrayRange(Builder, Address, Eight8, 64, 71);
6042 
6043   // 72-87: d0-15, the 8-byte floating-point registers
6044   AssignToArrayRange(Builder, Address, Eight8, 72, 87);
6045 
6046   return false;
6047 }
6048 
6049 
6050 //===----------------------------------------------------------------------===//
6051 // XCore ABI Implementation
6052 //===----------------------------------------------------------------------===//
6053 
6054 namespace {
6055 
6056 /// A SmallStringEnc instance is used to build up the TypeString by passing
6057 /// it by reference between functions that append to it.
6058 typedef llvm::SmallString<128> SmallStringEnc;
6059 
6060 /// TypeStringCache caches the meta encodings of Types.
6061 ///
6062 /// The reason for caching TypeStrings is two fold:
6063 ///   1. To cache a type's encoding for later uses;
6064 ///   2. As a means to break recursive member type inclusion.
6065 ///
6066 /// A cache Entry can have a Status of:
6067 ///   NonRecursive:   The type encoding is not recursive;
6068 ///   Recursive:      The type encoding is recursive;
6069 ///   Incomplete:     An incomplete TypeString;
6070 ///   IncompleteUsed: An incomplete TypeString that has been used in a
6071 ///                   Recursive type encoding.
6072 ///
6073 /// A NonRecursive entry will have all of its sub-members expanded as fully
6074 /// as possible. Whilst it may contain types which are recursive, the type
6075 /// itself is not recursive and thus its encoding may be safely used whenever
6076 /// the type is encountered.
6077 ///
6078 /// A Recursive entry will have all of its sub-members expanded as fully as
6079 /// possible. The type itself is recursive and it may contain other types which
6080 /// are recursive. The Recursive encoding must not be used during the expansion
6081 /// of a recursive type's recursive branch. For simplicity the code uses
6082 /// IncompleteCount to reject all usage of Recursive encodings for member types.
6083 ///
6084 /// An Incomplete entry is always a RecordType and only encodes its
6085 /// identifier e.g. "s(S){}". Incomplete 'StubEnc' entries are ephemeral and
6086 /// are placed into the cache during type expansion as a means to identify and
6087 /// handle recursive inclusion of types as sub-members. If there is recursion
6088 /// the entry becomes IncompleteUsed.
6089 ///
6090 /// During the expansion of a RecordType's members:
6091 ///
6092 ///   If the cache contains a NonRecursive encoding for the member type, the
6093 ///   cached encoding is used;
6094 ///
6095 ///   If the cache contains a Recursive encoding for the member type, the
6096 ///   cached encoding is 'Swapped' out, as it may be incorrect, and...
6097 ///
6098 ///   If the member is a RecordType, an Incomplete encoding is placed into the
6099 ///   cache to break potential recursive inclusion of itself as a sub-member;
6100 ///
6101 ///   Once a member RecordType has been expanded, its temporary incomplete
6102 ///   entry is removed from the cache. If a Recursive encoding was swapped out
6103 ///   it is swapped back in;
6104 ///
6105 ///   If an incomplete entry is used to expand a sub-member, the incomplete
6106 ///   entry is marked as IncompleteUsed. The cache keeps count of how many
6107 ///   IncompleteUsed entries it currently contains in IncompleteUsedCount;
6108 ///
6109 ///   If a member's encoding is found to be a NonRecursive or Recursive viz:
6110 ///   IncompleteUsedCount==0, the member's encoding is added to the cache.
6111 ///   Else the member is part of a recursive type and thus the recursion has
6112 ///   been exited too soon for the encoding to be correct for the member.
6113 ///
6114 class TypeStringCache {
6115   enum Status {NonRecursive, Recursive, Incomplete, IncompleteUsed};
6116   struct Entry {
6117     std::string Str;     // The encoded TypeString for the type.
6118     enum Status State;   // Information about the encoding in 'Str'.
6119     std::string Swapped; // A temporary place holder for a Recursive encoding
6120                          // during the expansion of RecordType's members.
6121   };
6122   std::map<const IdentifierInfo *, struct Entry> Map;
6123   unsigned IncompleteCount;     // Number of Incomplete entries in the Map.
6124   unsigned IncompleteUsedCount; // Number of IncompleteUsed entries in the Map.
6125 public:
6126   TypeStringCache() : IncompleteCount(0), IncompleteUsedCount(0) {};
6127   void addIncomplete(const IdentifierInfo *ID, std::string StubEnc);
6128   bool removeIncomplete(const IdentifierInfo *ID);
6129   void addIfComplete(const IdentifierInfo *ID, StringRef Str,
6130                      bool IsRecursive);
6131   StringRef lookupStr(const IdentifierInfo *ID);
6132 };
6133 
6134 /// TypeString encodings for union fields must be order.
6135 /// FieldEncoding is a helper for this ordering process.
6136 class FieldEncoding {
6137   bool HasName;
6138   std::string Enc;
6139 public:
6140   FieldEncoding(bool b, SmallStringEnc &e) : HasName(b), Enc(e.c_str()) {};
6141   StringRef str() {return Enc.c_str();};
6142   bool operator<(const FieldEncoding &rhs) const {
6143     if (HasName != rhs.HasName) return HasName;
6144     return Enc < rhs.Enc;
6145   }
6146 };
6147 
6148 class XCoreABIInfo : public DefaultABIInfo {
6149 public:
6150   XCoreABIInfo(CodeGen::CodeGenTypes &CGT) : DefaultABIInfo(CGT) {}
6151   llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
6152                          CodeGenFunction &CGF) const override;
6153 };
6154 
6155 class XCoreTargetCodeGenInfo : public TargetCodeGenInfo {
6156   mutable TypeStringCache TSC;
6157 public:
6158   XCoreTargetCodeGenInfo(CodeGenTypes &CGT)
6159     :TargetCodeGenInfo(new XCoreABIInfo(CGT)) {}
6160   void emitTargetMD(const Decl *D, llvm::GlobalValue *GV,
6161                     CodeGen::CodeGenModule &M) const override;
6162 };
6163 
6164 } // End anonymous namespace.
6165 
6166 llvm::Value *XCoreABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
6167                                      CodeGenFunction &CGF) const {
6168   CGBuilderTy &Builder = CGF.Builder;
6169 
6170   // Get the VAList.
6171   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr,
6172                                                        CGF.Int8PtrPtrTy);
6173   llvm::Value *AP = Builder.CreateLoad(VAListAddrAsBPP);
6174 
6175   // Handle the argument.
6176   ABIArgInfo AI = classifyArgumentType(Ty);
6177   llvm::Type *ArgTy = CGT.ConvertType(Ty);
6178   if (AI.canHaveCoerceToType() && !AI.getCoerceToType())
6179     AI.setCoerceToType(ArgTy);
6180   llvm::Type *ArgPtrTy = llvm::PointerType::getUnqual(ArgTy);
6181   llvm::Value *Val;
6182   uint64_t ArgSize = 0;
6183   switch (AI.getKind()) {
6184   case ABIArgInfo::Expand:
6185   case ABIArgInfo::InAlloca:
6186     llvm_unreachable("Unsupported ABI kind for va_arg");
6187   case ABIArgInfo::Ignore:
6188     Val = llvm::UndefValue::get(ArgPtrTy);
6189     ArgSize = 0;
6190     break;
6191   case ABIArgInfo::Extend:
6192   case ABIArgInfo::Direct:
6193     Val = Builder.CreatePointerCast(AP, ArgPtrTy);
6194     ArgSize = getDataLayout().getTypeAllocSize(AI.getCoerceToType());
6195     if (ArgSize < 4)
6196       ArgSize = 4;
6197     break;
6198   case ABIArgInfo::Indirect:
6199     llvm::Value *ArgAddr;
6200     ArgAddr = Builder.CreateBitCast(AP, llvm::PointerType::getUnqual(ArgPtrTy));
6201     ArgAddr = Builder.CreateLoad(ArgAddr);
6202     Val = Builder.CreatePointerCast(ArgAddr, ArgPtrTy);
6203     ArgSize = 4;
6204     break;
6205   }
6206 
6207   // Increment the VAList.
6208   if (ArgSize) {
6209     llvm::Value *APN = Builder.CreateConstGEP1_32(AP, ArgSize);
6210     Builder.CreateStore(APN, VAListAddrAsBPP);
6211   }
6212   return Val;
6213 }
6214 
6215 /// During the expansion of a RecordType, an incomplete TypeString is placed
6216 /// into the cache as a means to identify and break recursion.
6217 /// If there is a Recursive encoding in the cache, it is swapped out and will
6218 /// be reinserted by removeIncomplete().
6219 /// All other types of encoding should have been used rather than arriving here.
6220 void TypeStringCache::addIncomplete(const IdentifierInfo *ID,
6221                                     std::string StubEnc) {
6222   if (!ID)
6223     return;
6224   Entry &E = Map[ID];
6225   assert( (E.Str.empty() || E.State == Recursive) &&
6226          "Incorrectly use of addIncomplete");
6227   assert(!StubEnc.empty() && "Passing an empty string to addIncomplete()");
6228   E.Swapped.swap(E.Str); // swap out the Recursive
6229   E.Str.swap(StubEnc);
6230   E.State = Incomplete;
6231   ++IncompleteCount;
6232 }
6233 
6234 /// Once the RecordType has been expanded, the temporary incomplete TypeString
6235 /// must be removed from the cache.
6236 /// If a Recursive was swapped out by addIncomplete(), it will be replaced.
6237 /// Returns true if the RecordType was defined recursively.
6238 bool TypeStringCache::removeIncomplete(const IdentifierInfo *ID) {
6239   if (!ID)
6240     return false;
6241   auto I = Map.find(ID);
6242   assert(I != Map.end() && "Entry not present");
6243   Entry &E = I->second;
6244   assert( (E.State == Incomplete ||
6245            E.State == IncompleteUsed) &&
6246          "Entry must be an incomplete type");
6247   bool IsRecursive = false;
6248   if (E.State == IncompleteUsed) {
6249     // We made use of our Incomplete encoding, thus we are recursive.
6250     IsRecursive = true;
6251     --IncompleteUsedCount;
6252   }
6253   if (E.Swapped.empty())
6254     Map.erase(I);
6255   else {
6256     // Swap the Recursive back.
6257     E.Swapped.swap(E.Str);
6258     E.Swapped.clear();
6259     E.State = Recursive;
6260   }
6261   --IncompleteCount;
6262   return IsRecursive;
6263 }
6264 
6265 /// Add the encoded TypeString to the cache only if it is NonRecursive or
6266 /// Recursive (viz: all sub-members were expanded as fully as possible).
6267 void TypeStringCache::addIfComplete(const IdentifierInfo *ID, StringRef Str,
6268                                     bool IsRecursive) {
6269   if (!ID || IncompleteUsedCount)
6270     return; // No key or it is is an incomplete sub-type so don't add.
6271   Entry &E = Map[ID];
6272   if (IsRecursive && !E.Str.empty()) {
6273     assert(E.State==Recursive && E.Str.size() == Str.size() &&
6274            "This is not the same Recursive entry");
6275     // The parent container was not recursive after all, so we could have used
6276     // this Recursive sub-member entry after all, but we assumed the worse when
6277     // we started viz: IncompleteCount!=0.
6278     return;
6279   }
6280   assert(E.Str.empty() && "Entry already present");
6281   E.Str = Str.str();
6282   E.State = IsRecursive? Recursive : NonRecursive;
6283 }
6284 
6285 /// Return a cached TypeString encoding for the ID. If there isn't one, or we
6286 /// are recursively expanding a type (IncompleteCount != 0) and the cached
6287 /// encoding is Recursive, return an empty StringRef.
6288 StringRef TypeStringCache::lookupStr(const IdentifierInfo *ID) {
6289   if (!ID)
6290     return StringRef();   // We have no key.
6291   auto I = Map.find(ID);
6292   if (I == Map.end())
6293     return StringRef();   // We have no encoding.
6294   Entry &E = I->second;
6295   if (E.State == Recursive && IncompleteCount)
6296     return StringRef();   // We don't use Recursive encodings for member types.
6297 
6298   if (E.State == Incomplete) {
6299     // The incomplete type is being used to break out of recursion.
6300     E.State = IncompleteUsed;
6301     ++IncompleteUsedCount;
6302   }
6303   return E.Str.c_str();
6304 }
6305 
6306 /// The XCore ABI includes a type information section that communicates symbol
6307 /// type information to the linker. The linker uses this information to verify
6308 /// safety/correctness of things such as array bound and pointers et al.
6309 /// The ABI only requires C (and XC) language modules to emit TypeStrings.
6310 /// This type information (TypeString) is emitted into meta data for all global
6311 /// symbols: definitions, declarations, functions & variables.
6312 ///
6313 /// The TypeString carries type, qualifier, name, size & value details.
6314 /// Please see 'Tools Development Guide' section 2.16.2 for format details:
6315 /// <https://www.xmos.com/download/public/Tools-Development-Guide%28X9114A%29.pdf>
6316 /// The output is tested by test/CodeGen/xcore-stringtype.c.
6317 ///
6318 static bool getTypeString(SmallStringEnc &Enc, const Decl *D,
6319                           CodeGen::CodeGenModule &CGM, TypeStringCache &TSC);
6320 
6321 /// XCore uses emitTargetMD to emit TypeString metadata for global symbols.
6322 void XCoreTargetCodeGenInfo::emitTargetMD(const Decl *D, llvm::GlobalValue *GV,
6323                                           CodeGen::CodeGenModule &CGM) const {
6324   SmallStringEnc Enc;
6325   if (getTypeString(Enc, D, CGM, TSC)) {
6326     llvm::LLVMContext &Ctx = CGM.getModule().getContext();
6327     llvm::SmallVector<llvm::Value *, 2> MDVals;
6328     MDVals.push_back(GV);
6329     MDVals.push_back(llvm::MDString::get(Ctx, Enc.str()));
6330     llvm::NamedMDNode *MD =
6331       CGM.getModule().getOrInsertNamedMetadata("xcore.typestrings");
6332     MD->addOperand(llvm::MDNode::get(Ctx, MDVals));
6333   }
6334 }
6335 
6336 static bool appendType(SmallStringEnc &Enc, QualType QType,
6337                        const CodeGen::CodeGenModule &CGM,
6338                        TypeStringCache &TSC);
6339 
6340 /// Helper function for appendRecordType().
6341 /// Builds a SmallVector containing the encoded field types in declaration order.
6342 static bool extractFieldType(SmallVectorImpl<FieldEncoding> &FE,
6343                              const RecordDecl *RD,
6344                              const CodeGen::CodeGenModule &CGM,
6345                              TypeStringCache &TSC) {
6346   for (RecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end();
6347        I != E; ++I) {
6348     SmallStringEnc Enc;
6349     Enc += "m(";
6350     Enc += I->getName();
6351     Enc += "){";
6352     if (I->isBitField()) {
6353       Enc += "b(";
6354       llvm::raw_svector_ostream OS(Enc);
6355       OS.resync();
6356       OS << I->getBitWidthValue(CGM.getContext());
6357       OS.flush();
6358       Enc += ':';
6359     }
6360     if (!appendType(Enc, I->getType(), CGM, TSC))
6361       return false;
6362     if (I->isBitField())
6363       Enc += ')';
6364     Enc += '}';
6365     FE.push_back(FieldEncoding(!I->getName().empty(), Enc));
6366   }
6367   return true;
6368 }
6369 
6370 /// Appends structure and union types to Enc and adds encoding to cache.
6371 /// Recursively calls appendType (via extractFieldType) for each field.
6372 /// Union types have their fields ordered according to the ABI.
6373 static bool appendRecordType(SmallStringEnc &Enc, const RecordType *RT,
6374                              const CodeGen::CodeGenModule &CGM,
6375                              TypeStringCache &TSC, const IdentifierInfo *ID) {
6376   // Append the cached TypeString if we have one.
6377   StringRef TypeString = TSC.lookupStr(ID);
6378   if (!TypeString.empty()) {
6379     Enc += TypeString;
6380     return true;
6381   }
6382 
6383   // Start to emit an incomplete TypeString.
6384   size_t Start = Enc.size();
6385   Enc += (RT->isUnionType()? 'u' : 's');
6386   Enc += '(';
6387   if (ID)
6388     Enc += ID->getName();
6389   Enc += "){";
6390 
6391   // We collect all encoded fields and order as necessary.
6392   bool IsRecursive = false;
6393   SmallVector<FieldEncoding, 16> FE;
6394   const RecordDecl *RD = RT->getDecl()->getDefinition();
6395   if (RD && !RD->field_empty()) {
6396     // An incomplete TypeString stub is placed in the cache for this RecordType
6397     // so that recursive calls to this RecordType will use it whilst building a
6398     // complete TypeString for this RecordType.
6399     std::string StubEnc(Enc.substr(Start).str());
6400     StubEnc += '}';  // StubEnc now holds a valid incomplete TypeString.
6401     TSC.addIncomplete(ID, std::move(StubEnc));
6402     if (!extractFieldType(FE, RD, CGM, TSC)) {
6403       (void) TSC.removeIncomplete(ID);
6404       return false;
6405     }
6406     IsRecursive = TSC.removeIncomplete(ID);
6407     // The ABI requires unions to be sorted but not structures.
6408     // See FieldEncoding::operator< for sort algorithm.
6409     if (RT->isUnionType())
6410       std::sort(FE.begin(), FE.end());
6411   }
6412 
6413   // We can now complete the TypeString.
6414   if (unsigned E = FE.size())
6415     for (unsigned I = 0; I != E; ++I) {
6416       if (I)
6417         Enc += ',';
6418       Enc += FE[I].str();
6419     }
6420   Enc += '}';
6421   TSC.addIfComplete(ID, Enc.substr(Start), IsRecursive);
6422   return true;
6423 }
6424 
6425 /// Appends enum types to Enc and adds the encoding to the cache.
6426 static bool appendEnumType(SmallStringEnc &Enc, const EnumType *ET,
6427                            TypeStringCache &TSC,
6428                            const IdentifierInfo *ID) {
6429   // Append the cached TypeString if we have one.
6430   StringRef TypeString = TSC.lookupStr(ID);
6431   if (!TypeString.empty()) {
6432     Enc += TypeString;
6433     return true;
6434   }
6435 
6436   size_t Start = Enc.size();
6437   Enc += "e(";
6438   if (ID)
6439     Enc += ID->getName();
6440   Enc += "){";
6441   if (const EnumDecl *ED = ET->getDecl()->getDefinition()) {
6442     auto I = ED->enumerator_begin();
6443     auto E = ED->enumerator_end();
6444     while (I != E) {
6445       Enc += "m(";
6446       Enc += I->getName();
6447       Enc += "){";
6448       I->getInitVal().toString(Enc);
6449       Enc += '}';
6450       ++I;
6451       if (I != E)
6452         Enc += ',';
6453     }
6454   }
6455   Enc += '}';
6456   TSC.addIfComplete(ID, Enc.substr(Start), false);
6457   return true;
6458 }
6459 
6460 /// Appends type's qualifier to Enc.
6461 /// This is done prior to appending the type's encoding.
6462 static void appendQualifier(SmallStringEnc &Enc, QualType QT) {
6463   // Qualifiers are emitted in alphabetical order.
6464   static const char *Table[] = {"","c:","r:","cr:","v:","cv:","rv:","crv:"};
6465   int Lookup = 0;
6466   if (QT.isConstQualified())
6467     Lookup += 1<<0;
6468   if (QT.isRestrictQualified())
6469     Lookup += 1<<1;
6470   if (QT.isVolatileQualified())
6471     Lookup += 1<<2;
6472   Enc += Table[Lookup];
6473 }
6474 
6475 /// Appends built-in types to Enc.
6476 static bool appendBuiltinType(SmallStringEnc &Enc, const BuiltinType *BT) {
6477   const char *EncType;
6478   switch (BT->getKind()) {
6479     case BuiltinType::Void:
6480       EncType = "0";
6481       break;
6482     case BuiltinType::Bool:
6483       EncType = "b";
6484       break;
6485     case BuiltinType::Char_U:
6486       EncType = "uc";
6487       break;
6488     case BuiltinType::UChar:
6489       EncType = "uc";
6490       break;
6491     case BuiltinType::SChar:
6492       EncType = "sc";
6493       break;
6494     case BuiltinType::UShort:
6495       EncType = "us";
6496       break;
6497     case BuiltinType::Short:
6498       EncType = "ss";
6499       break;
6500     case BuiltinType::UInt:
6501       EncType = "ui";
6502       break;
6503     case BuiltinType::Int:
6504       EncType = "si";
6505       break;
6506     case BuiltinType::ULong:
6507       EncType = "ul";
6508       break;
6509     case BuiltinType::Long:
6510       EncType = "sl";
6511       break;
6512     case BuiltinType::ULongLong:
6513       EncType = "ull";
6514       break;
6515     case BuiltinType::LongLong:
6516       EncType = "sll";
6517       break;
6518     case BuiltinType::Float:
6519       EncType = "ft";
6520       break;
6521     case BuiltinType::Double:
6522       EncType = "d";
6523       break;
6524     case BuiltinType::LongDouble:
6525       EncType = "ld";
6526       break;
6527     default:
6528       return false;
6529   }
6530   Enc += EncType;
6531   return true;
6532 }
6533 
6534 /// Appends a pointer encoding to Enc before calling appendType for the pointee.
6535 static bool appendPointerType(SmallStringEnc &Enc, const PointerType *PT,
6536                               const CodeGen::CodeGenModule &CGM,
6537                               TypeStringCache &TSC) {
6538   Enc += "p(";
6539   if (!appendType(Enc, PT->getPointeeType(), CGM, TSC))
6540     return false;
6541   Enc += ')';
6542   return true;
6543 }
6544 
6545 /// Appends array encoding to Enc before calling appendType for the element.
6546 static bool appendArrayType(SmallStringEnc &Enc, const ArrayType *AT,
6547                             const CodeGen::CodeGenModule &CGM,
6548                             TypeStringCache &TSC, StringRef NoSizeEnc) {
6549   if (AT->getSizeModifier() != ArrayType::Normal)
6550     return false;
6551   Enc += "a(";
6552   if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(AT))
6553     CAT->getSize().toStringUnsigned(Enc);
6554   else
6555     Enc += NoSizeEnc; // Global arrays use "*", otherwise it is "".
6556   Enc += ':';
6557   if (!appendType(Enc, AT->getElementType(), CGM, TSC))
6558     return false;
6559   Enc += ')';
6560   return true;
6561 }
6562 
6563 /// Appends a function encoding to Enc, calling appendType for the return type
6564 /// and the arguments.
6565 static bool appendFunctionType(SmallStringEnc &Enc, const FunctionType *FT,
6566                              const CodeGen::CodeGenModule &CGM,
6567                              TypeStringCache &TSC) {
6568   Enc += "f{";
6569   if (!appendType(Enc, FT->getReturnType(), CGM, TSC))
6570     return false;
6571   Enc += "}(";
6572   if (const FunctionProtoType *FPT = FT->getAs<FunctionProtoType>()) {
6573     // N.B. we are only interested in the adjusted param types.
6574     auto I = FPT->param_type_begin();
6575     auto E = FPT->param_type_end();
6576     if (I != E) {
6577       do {
6578         if (!appendType(Enc, *I, CGM, TSC))
6579           return false;
6580         ++I;
6581         if (I != E)
6582           Enc += ',';
6583       } while (I != E);
6584       if (FPT->isVariadic())
6585         Enc += ",va";
6586     } else {
6587       if (FPT->isVariadic())
6588         Enc += "va";
6589       else
6590         Enc += '0';
6591     }
6592   }
6593   Enc += ')';
6594   return true;
6595 }
6596 
6597 /// Handles the type's qualifier before dispatching a call to handle specific
6598 /// type encodings.
6599 static bool appendType(SmallStringEnc &Enc, QualType QType,
6600                        const CodeGen::CodeGenModule &CGM,
6601                        TypeStringCache &TSC) {
6602 
6603   QualType QT = QType.getCanonicalType();
6604 
6605   appendQualifier(Enc, QT);
6606 
6607   if (const BuiltinType *BT = QT->getAs<BuiltinType>())
6608     return appendBuiltinType(Enc, BT);
6609 
6610   if (const ArrayType *AT = QT->getAsArrayTypeUnsafe())
6611     return appendArrayType(Enc, AT, CGM, TSC, "");
6612 
6613   if (const PointerType *PT = QT->getAs<PointerType>())
6614     return appendPointerType(Enc, PT, CGM, TSC);
6615 
6616   if (const EnumType *ET = QT->getAs<EnumType>())
6617     return appendEnumType(Enc, ET, TSC, QT.getBaseTypeIdentifier());
6618 
6619   if (const RecordType *RT = QT->getAsStructureType())
6620     return appendRecordType(Enc, RT, CGM, TSC, QT.getBaseTypeIdentifier());
6621 
6622   if (const RecordType *RT = QT->getAsUnionType())
6623     return appendRecordType(Enc, RT, CGM, TSC, QT.getBaseTypeIdentifier());
6624 
6625   if (const FunctionType *FT = QT->getAs<FunctionType>())
6626     return appendFunctionType(Enc, FT, CGM, TSC);
6627 
6628   return false;
6629 }
6630 
6631 static bool getTypeString(SmallStringEnc &Enc, const Decl *D,
6632                           CodeGen::CodeGenModule &CGM, TypeStringCache &TSC) {
6633   if (!D)
6634     return false;
6635 
6636   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
6637     if (FD->getLanguageLinkage() != CLanguageLinkage)
6638       return false;
6639     return appendType(Enc, FD->getType(), CGM, TSC);
6640   }
6641 
6642   if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
6643     if (VD->getLanguageLinkage() != CLanguageLinkage)
6644       return false;
6645     QualType QT = VD->getType().getCanonicalType();
6646     if (const ArrayType *AT = QT->getAsArrayTypeUnsafe()) {
6647       // Global ArrayTypes are given a size of '*' if the size is unknown.
6648       appendQualifier(Enc, QT);
6649       return appendArrayType(Enc, AT, CGM, TSC, "*");
6650     }
6651     return appendType(Enc, QT, CGM, TSC);
6652   }
6653   return false;
6654 }
6655 
6656 
6657 //===----------------------------------------------------------------------===//
6658 // Driver code
6659 //===----------------------------------------------------------------------===//
6660 
6661 const TargetCodeGenInfo &CodeGenModule::getTargetCodeGenInfo() {
6662   if (TheTargetCodeGenInfo)
6663     return *TheTargetCodeGenInfo;
6664 
6665   const llvm::Triple &Triple = getTarget().getTriple();
6666   switch (Triple.getArch()) {
6667   default:
6668     return *(TheTargetCodeGenInfo = new DefaultTargetCodeGenInfo(Types));
6669 
6670   case llvm::Triple::le32:
6671     return *(TheTargetCodeGenInfo = new PNaClTargetCodeGenInfo(Types));
6672   case llvm::Triple::mips:
6673   case llvm::Triple::mipsel:
6674     return *(TheTargetCodeGenInfo = new MIPSTargetCodeGenInfo(Types, true));
6675 
6676   case llvm::Triple::mips64:
6677   case llvm::Triple::mips64el:
6678     return *(TheTargetCodeGenInfo = new MIPSTargetCodeGenInfo(Types, false));
6679 
6680   case llvm::Triple::arm64:
6681   case llvm::Triple::arm64_be: {
6682     ARM64ABIInfo::ABIKind Kind = ARM64ABIInfo::AAPCS;
6683     if (strcmp(getTarget().getABI(), "darwinpcs") == 0)
6684       Kind = ARM64ABIInfo::DarwinPCS;
6685 
6686     return *(TheTargetCodeGenInfo = new ARM64TargetCodeGenInfo(Types, Kind));
6687   }
6688 
6689   case llvm::Triple::aarch64:
6690   case llvm::Triple::aarch64_be:
6691     return *(TheTargetCodeGenInfo = new AArch64TargetCodeGenInfo(Types));
6692 
6693   case llvm::Triple::arm:
6694   case llvm::Triple::armeb:
6695   case llvm::Triple::thumb:
6696   case llvm::Triple::thumbeb:
6697     {
6698       ARMABIInfo::ABIKind Kind = ARMABIInfo::AAPCS;
6699       if (strcmp(getTarget().getABI(), "apcs-gnu") == 0)
6700         Kind = ARMABIInfo::APCS;
6701       else if (CodeGenOpts.FloatABI == "hard" ||
6702                (CodeGenOpts.FloatABI != "soft" &&
6703                 Triple.getEnvironment() == llvm::Triple::GNUEABIHF))
6704         Kind = ARMABIInfo::AAPCS_VFP;
6705 
6706       switch (Triple.getOS()) {
6707         case llvm::Triple::NaCl:
6708           return *(TheTargetCodeGenInfo =
6709                    new NaClARMTargetCodeGenInfo(Types, Kind));
6710         default:
6711           return *(TheTargetCodeGenInfo =
6712                    new ARMTargetCodeGenInfo(Types, Kind));
6713       }
6714     }
6715 
6716   case llvm::Triple::ppc:
6717     return *(TheTargetCodeGenInfo = new PPC32TargetCodeGenInfo(Types));
6718   case llvm::Triple::ppc64:
6719     if (Triple.isOSBinFormatELF())
6720       return *(TheTargetCodeGenInfo = new PPC64_SVR4_TargetCodeGenInfo(Types));
6721     else
6722       return *(TheTargetCodeGenInfo = new PPC64TargetCodeGenInfo(Types));
6723   case llvm::Triple::ppc64le:
6724     assert(Triple.isOSBinFormatELF() && "PPC64 LE non-ELF not supported!");
6725     return *(TheTargetCodeGenInfo = new PPC64_SVR4_TargetCodeGenInfo(Types));
6726 
6727   case llvm::Triple::nvptx:
6728   case llvm::Triple::nvptx64:
6729     return *(TheTargetCodeGenInfo = new NVPTXTargetCodeGenInfo(Types));
6730 
6731   case llvm::Triple::msp430:
6732     return *(TheTargetCodeGenInfo = new MSP430TargetCodeGenInfo(Types));
6733 
6734   case llvm::Triple::systemz:
6735     return *(TheTargetCodeGenInfo = new SystemZTargetCodeGenInfo(Types));
6736 
6737   case llvm::Triple::tce:
6738     return *(TheTargetCodeGenInfo = new TCETargetCodeGenInfo(Types));
6739 
6740   case llvm::Triple::x86: {
6741     bool IsDarwinVectorABI = Triple.isOSDarwin();
6742     bool IsSmallStructInRegABI =
6743         X86_32TargetCodeGenInfo::isStructReturnInRegABI(Triple, CodeGenOpts);
6744     bool IsWin32FloatStructABI = Triple.isWindowsMSVCEnvironment();
6745 
6746     if (Triple.getOS() == llvm::Triple::Win32) {
6747       return *(TheTargetCodeGenInfo =
6748                new WinX86_32TargetCodeGenInfo(Types,
6749                                               IsDarwinVectorABI, IsSmallStructInRegABI,
6750                                               IsWin32FloatStructABI,
6751                                               CodeGenOpts.NumRegisterParameters));
6752     } else {
6753       return *(TheTargetCodeGenInfo =
6754                new X86_32TargetCodeGenInfo(Types,
6755                                            IsDarwinVectorABI, IsSmallStructInRegABI,
6756                                            IsWin32FloatStructABI,
6757                                            CodeGenOpts.NumRegisterParameters));
6758     }
6759   }
6760 
6761   case llvm::Triple::x86_64: {
6762     bool HasAVX = strcmp(getTarget().getABI(), "avx") == 0;
6763 
6764     switch (Triple.getOS()) {
6765     case llvm::Triple::Win32:
6766       return *(TheTargetCodeGenInfo = new WinX86_64TargetCodeGenInfo(Types));
6767     case llvm::Triple::NaCl:
6768       return *(TheTargetCodeGenInfo = new NaClX86_64TargetCodeGenInfo(Types,
6769                                                                       HasAVX));
6770     default:
6771       return *(TheTargetCodeGenInfo = new X86_64TargetCodeGenInfo(Types,
6772                                                                   HasAVX));
6773     }
6774   }
6775   case llvm::Triple::hexagon:
6776     return *(TheTargetCodeGenInfo = new HexagonTargetCodeGenInfo(Types));
6777   case llvm::Triple::sparcv9:
6778     return *(TheTargetCodeGenInfo = new SparcV9TargetCodeGenInfo(Types));
6779   case llvm::Triple::xcore:
6780     return *(TheTargetCodeGenInfo = new XCoreTargetCodeGenInfo(Types));
6781   }
6782 }
6783