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 "CodeGenFunction.h"
18 #include "clang/AST/RecordLayout.h"
19 #include "clang/Frontend/CodeGenOptions.h"
20 #include "llvm/Type.h"
21 #include "llvm/Target/TargetData.h"
22 #include "llvm/ADT/Triple.h"
23 #include "llvm/Support/raw_ostream.h"
24 using namespace clang;
25 using namespace CodeGen;
26 
27 static void AssignToArrayRange(CodeGen::CGBuilderTy &Builder,
28                                llvm::Value *Array,
29                                llvm::Value *Value,
30                                unsigned FirstIndex,
31                                unsigned LastIndex) {
32   // Alternatively, we could emit this as a loop in the source.
33   for (unsigned I = FirstIndex; I <= LastIndex; ++I) {
34     llvm::Value *Cell = Builder.CreateConstInBoundsGEP1_32(Array, I);
35     Builder.CreateStore(Value, Cell);
36   }
37 }
38 
39 static bool isAggregateTypeForABI(QualType T) {
40   return CodeGenFunction::hasAggregateLLVMType(T) ||
41          T->isMemberFunctionPointerType();
42 }
43 
44 ABIInfo::~ABIInfo() {}
45 
46 ASTContext &ABIInfo::getContext() const {
47   return CGT.getContext();
48 }
49 
50 llvm::LLVMContext &ABIInfo::getVMContext() const {
51   return CGT.getLLVMContext();
52 }
53 
54 const llvm::TargetData &ABIInfo::getTargetData() const {
55   return CGT.getTargetData();
56 }
57 
58 
59 void ABIArgInfo::dump() const {
60   raw_ostream &OS = llvm::errs();
61   OS << "(ABIArgInfo Kind=";
62   switch (TheKind) {
63   case Direct:
64     OS << "Direct Type=";
65     if (llvm::Type *Ty = getCoerceToType())
66       Ty->print(OS);
67     else
68       OS << "null";
69     break;
70   case Extend:
71     OS << "Extend";
72     break;
73   case Ignore:
74     OS << "Ignore";
75     break;
76   case Indirect:
77     OS << "Indirect Align=" << getIndirectAlign()
78        << " ByVal=" << getIndirectByVal()
79        << " Realign=" << getIndirectRealign();
80     break;
81   case Expand:
82     OS << "Expand";
83     break;
84   }
85   OS << ")\n";
86 }
87 
88 TargetCodeGenInfo::~TargetCodeGenInfo() { delete Info; }
89 
90 // If someone can figure out a general rule for this, that would be great.
91 // It's probably just doomed to be platform-dependent, though.
92 unsigned TargetCodeGenInfo::getSizeOfUnwindException() const {
93   // Verified for:
94   //   x86-64     FreeBSD, Linux, Darwin
95   //   x86-32     FreeBSD, Linux, Darwin
96   //   PowerPC    Linux, Darwin
97   //   ARM        Darwin (*not* EABI)
98   return 32;
99 }
100 
101 bool TargetCodeGenInfo::isNoProtoCallVariadic(const CallArgList &args,
102                                      const FunctionNoProtoType *fnType) const {
103   // The following conventions are known to require this to be false:
104   //   x86_stdcall
105   //   MIPS
106   // For everything else, we just prefer false unless we opt out.
107   return false;
108 }
109 
110 static bool isEmptyRecord(ASTContext &Context, QualType T, bool AllowArrays);
111 
112 /// isEmptyField - Return true iff a the field is "empty", that is it
113 /// is an unnamed bit-field or an (array of) empty record(s).
114 static bool isEmptyField(ASTContext &Context, const FieldDecl *FD,
115                          bool AllowArrays) {
116   if (FD->isUnnamedBitfield())
117     return true;
118 
119   QualType FT = FD->getType();
120 
121   // Constant arrays of empty records count as empty, strip them off.
122   // Constant arrays of zero length always count as empty.
123   if (AllowArrays)
124     while (const ConstantArrayType *AT = Context.getAsConstantArrayType(FT)) {
125       if (AT->getSize() == 0)
126         return true;
127       FT = AT->getElementType();
128     }
129 
130   const RecordType *RT = FT->getAs<RecordType>();
131   if (!RT)
132     return false;
133 
134   // C++ record fields are never empty, at least in the Itanium ABI.
135   //
136   // FIXME: We should use a predicate for whether this behavior is true in the
137   // current ABI.
138   if (isa<CXXRecordDecl>(RT->getDecl()))
139     return false;
140 
141   return isEmptyRecord(Context, FT, AllowArrays);
142 }
143 
144 /// isEmptyRecord - Return true iff a structure contains only empty
145 /// fields. Note that a structure with a flexible array member is not
146 /// considered empty.
147 static bool isEmptyRecord(ASTContext &Context, QualType T, bool AllowArrays) {
148   const RecordType *RT = T->getAs<RecordType>();
149   if (!RT)
150     return 0;
151   const RecordDecl *RD = RT->getDecl();
152   if (RD->hasFlexibleArrayMember())
153     return false;
154 
155   // If this is a C++ record, check the bases first.
156   if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD))
157     for (CXXRecordDecl::base_class_const_iterator i = CXXRD->bases_begin(),
158            e = CXXRD->bases_end(); i != e; ++i)
159       if (!isEmptyRecord(Context, i->getType(), true))
160         return false;
161 
162   for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
163          i != e; ++i)
164     if (!isEmptyField(Context, *i, AllowArrays))
165       return false;
166   return true;
167 }
168 
169 /// hasNonTrivialDestructorOrCopyConstructor - Determine if a type has either
170 /// a non-trivial destructor or a non-trivial copy constructor.
171 static bool hasNonTrivialDestructorOrCopyConstructor(const RecordType *RT) {
172   const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl());
173   if (!RD)
174     return false;
175 
176   return !RD->hasTrivialDestructor() || !RD->hasTrivialCopyConstructor();
177 }
178 
179 /// isRecordWithNonTrivialDestructorOrCopyConstructor - Determine if a type is
180 /// a record type with either a non-trivial destructor or a non-trivial copy
181 /// constructor.
182 static bool isRecordWithNonTrivialDestructorOrCopyConstructor(QualType T) {
183   const RecordType *RT = T->getAs<RecordType>();
184   if (!RT)
185     return false;
186 
187   return hasNonTrivialDestructorOrCopyConstructor(RT);
188 }
189 
190 /// isSingleElementStruct - Determine if a structure is a "single
191 /// element struct", i.e. it has exactly one non-empty field or
192 /// exactly one field which is itself a single element
193 /// struct. Structures with flexible array members are never
194 /// considered single element structs.
195 ///
196 /// \return The field declaration for the single non-empty field, if
197 /// it exists.
198 static const Type *isSingleElementStruct(QualType T, ASTContext &Context) {
199   const RecordType *RT = T->getAsStructureType();
200   if (!RT)
201     return 0;
202 
203   const RecordDecl *RD = RT->getDecl();
204   if (RD->hasFlexibleArrayMember())
205     return 0;
206 
207   const Type *Found = 0;
208 
209   // If this is a C++ record, check the bases first.
210   if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
211     for (CXXRecordDecl::base_class_const_iterator i = CXXRD->bases_begin(),
212            e = CXXRD->bases_end(); i != e; ++i) {
213       // Ignore empty records.
214       if (isEmptyRecord(Context, i->getType(), true))
215         continue;
216 
217       // If we already found an element then this isn't a single-element struct.
218       if (Found)
219         return 0;
220 
221       // If this is non-empty and not a single element struct, the composite
222       // cannot be a single element struct.
223       Found = isSingleElementStruct(i->getType(), Context);
224       if (!Found)
225         return 0;
226     }
227   }
228 
229   // Check for single element.
230   for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
231          i != e; ++i) {
232     const FieldDecl *FD = *i;
233     QualType FT = FD->getType();
234 
235     // Ignore empty fields.
236     if (isEmptyField(Context, FD, true))
237       continue;
238 
239     // If we already found an element then this isn't a single-element
240     // struct.
241     if (Found)
242       return 0;
243 
244     // Treat single element arrays as the element.
245     while (const ConstantArrayType *AT = Context.getAsConstantArrayType(FT)) {
246       if (AT->getSize().getZExtValue() != 1)
247         break;
248       FT = AT->getElementType();
249     }
250 
251     if (!isAggregateTypeForABI(FT)) {
252       Found = FT.getTypePtr();
253     } else {
254       Found = isSingleElementStruct(FT, Context);
255       if (!Found)
256         return 0;
257     }
258   }
259 
260   // We don't consider a struct a single-element struct if it has
261   // padding beyond the element type.
262   if (Found && Context.getTypeSize(Found) != Context.getTypeSize(T))
263     return 0;
264 
265   return Found;
266 }
267 
268 static bool is32Or64BitBasicType(QualType Ty, ASTContext &Context) {
269   if (!Ty->getAs<BuiltinType>() && !Ty->hasPointerRepresentation() &&
270       !Ty->isAnyComplexType() && !Ty->isEnumeralType() &&
271       !Ty->isBlockPointerType())
272     return false;
273 
274   uint64_t Size = Context.getTypeSize(Ty);
275   return Size == 32 || Size == 64;
276 }
277 
278 /// canExpandIndirectArgument - Test whether an argument type which is to be
279 /// passed indirectly (on the stack) would have the equivalent layout if it was
280 /// expanded into separate arguments. If so, we prefer to do the latter to avoid
281 /// inhibiting optimizations.
282 ///
283 // FIXME: This predicate is missing many cases, currently it just follows
284 // llvm-gcc (checks that all fields are 32-bit or 64-bit primitive types). We
285 // should probably make this smarter, or better yet make the LLVM backend
286 // capable of handling it.
287 static bool canExpandIndirectArgument(QualType Ty, ASTContext &Context) {
288   // We can only expand structure types.
289   const RecordType *RT = Ty->getAs<RecordType>();
290   if (!RT)
291     return false;
292 
293   // We can only expand (C) structures.
294   //
295   // FIXME: This needs to be generalized to handle classes as well.
296   const RecordDecl *RD = RT->getDecl();
297   if (!RD->isStruct() || isa<CXXRecordDecl>(RD))
298     return false;
299 
300   uint64_t Size = 0;
301 
302   for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
303          i != e; ++i) {
304     const FieldDecl *FD = *i;
305 
306     if (!is32Or64BitBasicType(FD->getType(), Context))
307       return false;
308 
309     // FIXME: Reject bit-fields wholesale; there are two problems, we don't know
310     // how to expand them yet, and the predicate for telling if a bitfield still
311     // counts as "basic" is more complicated than what we were doing previously.
312     if (FD->isBitField())
313       return false;
314 
315     Size += Context.getTypeSize(FD->getType());
316   }
317 
318   // Make sure there are not any holes in the struct.
319   if (Size != Context.getTypeSize(Ty))
320     return false;
321 
322   return true;
323 }
324 
325 namespace {
326 /// DefaultABIInfo - The default implementation for ABI specific
327 /// details. This implementation provides information which results in
328 /// self-consistent and sensible LLVM IR generation, but does not
329 /// conform to any particular ABI.
330 class DefaultABIInfo : public ABIInfo {
331 public:
332   DefaultABIInfo(CodeGen::CodeGenTypes &CGT) : ABIInfo(CGT) {}
333 
334   ABIArgInfo classifyReturnType(QualType RetTy) const;
335   ABIArgInfo classifyArgumentType(QualType RetTy) const;
336 
337   virtual void computeInfo(CGFunctionInfo &FI) const {
338     FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
339     for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
340          it != ie; ++it)
341       it->info = classifyArgumentType(it->type);
342   }
343 
344   virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
345                                  CodeGenFunction &CGF) const;
346 };
347 
348 class DefaultTargetCodeGenInfo : public TargetCodeGenInfo {
349 public:
350   DefaultTargetCodeGenInfo(CodeGen::CodeGenTypes &CGT)
351     : TargetCodeGenInfo(new DefaultABIInfo(CGT)) {}
352 };
353 
354 llvm::Value *DefaultABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
355                                        CodeGenFunction &CGF) const {
356   return 0;
357 }
358 
359 ABIArgInfo DefaultABIInfo::classifyArgumentType(QualType Ty) const {
360   if (isAggregateTypeForABI(Ty)) {
361     // Records with non trivial destructors/constructors should not be passed
362     // by value.
363     if (isRecordWithNonTrivialDestructorOrCopyConstructor(Ty))
364       return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
365 
366     return ABIArgInfo::getIndirect(0);
367   }
368 
369   // Treat an enum type as its underlying type.
370   if (const EnumType *EnumTy = Ty->getAs<EnumType>())
371     Ty = EnumTy->getDecl()->getIntegerType();
372 
373   return (Ty->isPromotableIntegerType() ?
374           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
375 }
376 
377 ABIArgInfo DefaultABIInfo::classifyReturnType(QualType RetTy) const {
378   if (RetTy->isVoidType())
379     return ABIArgInfo::getIgnore();
380 
381   if (isAggregateTypeForABI(RetTy))
382     return ABIArgInfo::getIndirect(0);
383 
384   // Treat an enum type as its underlying type.
385   if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
386     RetTy = EnumTy->getDecl()->getIntegerType();
387 
388   return (RetTy->isPromotableIntegerType() ?
389           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
390 }
391 
392 /// UseX86_MMXType - Return true if this is an MMX type that should use the
393 /// special x86_mmx type.
394 bool UseX86_MMXType(llvm::Type *IRType) {
395   // If the type is an MMX type <2 x i32>, <4 x i16>, or <8 x i8>, use the
396   // special x86_mmx type.
397   return IRType->isVectorTy() && IRType->getPrimitiveSizeInBits() == 64 &&
398     cast<llvm::VectorType>(IRType)->getElementType()->isIntegerTy() &&
399     IRType->getScalarSizeInBits() != 64;
400 }
401 
402 static llvm::Type* X86AdjustInlineAsmType(CodeGen::CodeGenFunction &CGF,
403                                           StringRef Constraint,
404                                           llvm::Type* Ty) {
405   if ((Constraint == "y" || Constraint == "&y") && Ty->isVectorTy())
406     return llvm::Type::getX86_MMXTy(CGF.getLLVMContext());
407   return Ty;
408 }
409 
410 //===----------------------------------------------------------------------===//
411 // X86-32 ABI Implementation
412 //===----------------------------------------------------------------------===//
413 
414 /// X86_32ABIInfo - The X86-32 ABI information.
415 class X86_32ABIInfo : public ABIInfo {
416   static const unsigned MinABIStackAlignInBytes = 4;
417 
418   bool IsDarwinVectorABI;
419   bool IsSmallStructInRegABI;
420   bool IsMMXDisabled;
421   bool IsWin32FloatStructABI;
422 
423   static bool isRegisterSize(unsigned Size) {
424     return (Size == 8 || Size == 16 || Size == 32 || Size == 64);
425   }
426 
427   static bool shouldReturnTypeInRegister(QualType Ty, ASTContext &Context,
428                                           unsigned callingConvention);
429 
430   /// getIndirectResult - Give a source type \arg Ty, return a suitable result
431   /// such that the argument will be passed in memory.
432   ABIArgInfo getIndirectResult(QualType Ty, bool ByVal = true) const;
433 
434   /// \brief Return the alignment to use for the given type on the stack.
435   unsigned getTypeStackAlignInBytes(QualType Ty, unsigned Align) const;
436 
437 public:
438 
439   ABIArgInfo classifyReturnType(QualType RetTy,
440                                 unsigned callingConvention) const;
441   ABIArgInfo classifyArgumentType(QualType RetTy) const;
442 
443   virtual void computeInfo(CGFunctionInfo &FI) const {
444     FI.getReturnInfo() = classifyReturnType(FI.getReturnType(),
445                                             FI.getCallingConvention());
446     for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
447          it != ie; ++it)
448       it->info = classifyArgumentType(it->type);
449   }
450 
451   virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
452                                  CodeGenFunction &CGF) const;
453 
454   X86_32ABIInfo(CodeGen::CodeGenTypes &CGT, bool d, bool p, bool m, bool w)
455     : ABIInfo(CGT), IsDarwinVectorABI(d), IsSmallStructInRegABI(p),
456       IsMMXDisabled(m), IsWin32FloatStructABI(w) {}
457 };
458 
459 class X86_32TargetCodeGenInfo : public TargetCodeGenInfo {
460 public:
461   X86_32TargetCodeGenInfo(CodeGen::CodeGenTypes &CGT,
462       bool d, bool p, bool m, bool w)
463     :TargetCodeGenInfo(new X86_32ABIInfo(CGT, d, p, m, w)) {}
464 
465   void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
466                            CodeGen::CodeGenModule &CGM) const;
467 
468   int getDwarfEHStackPointer(CodeGen::CodeGenModule &CGM) const {
469     // Darwin uses different dwarf register numbers for EH.
470     if (CGM.isTargetDarwin()) return 5;
471 
472     return 4;
473   }
474 
475   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
476                                llvm::Value *Address) const;
477 
478   llvm::Type* adjustInlineAsmType(CodeGen::CodeGenFunction &CGF,
479                                   StringRef Constraint,
480                                   llvm::Type* Ty) const {
481     return X86AdjustInlineAsmType(CGF, Constraint, Ty);
482   }
483 
484 };
485 
486 }
487 
488 /// shouldReturnTypeInRegister - Determine if the given type should be
489 /// passed in a register (for the Darwin ABI).
490 bool X86_32ABIInfo::shouldReturnTypeInRegister(QualType Ty,
491                                                ASTContext &Context,
492                                                unsigned callingConvention) {
493   uint64_t Size = Context.getTypeSize(Ty);
494 
495   // Type must be register sized.
496   if (!isRegisterSize(Size))
497     return false;
498 
499   if (Ty->isVectorType()) {
500     // 64- and 128- bit vectors inside structures are not returned in
501     // registers.
502     if (Size == 64 || Size == 128)
503       return false;
504 
505     return true;
506   }
507 
508   // If this is a builtin, pointer, enum, complex type, member pointer, or
509   // member function pointer it is ok.
510   if (Ty->getAs<BuiltinType>() || Ty->hasPointerRepresentation() ||
511       Ty->isAnyComplexType() || Ty->isEnumeralType() ||
512       Ty->isBlockPointerType() || Ty->isMemberPointerType())
513     return true;
514 
515   // Arrays are treated like records.
516   if (const ConstantArrayType *AT = Context.getAsConstantArrayType(Ty))
517     return shouldReturnTypeInRegister(AT->getElementType(), Context,
518                                       callingConvention);
519 
520   // Otherwise, it must be a record type.
521   const RecordType *RT = Ty->getAs<RecordType>();
522   if (!RT) return false;
523 
524   // FIXME: Traverse bases here too.
525 
526   // For thiscall conventions, structures will never be returned in
527   // a register.  This is for compatibility with the MSVC ABI
528   if (callingConvention == llvm::CallingConv::X86_ThisCall &&
529       RT->isStructureType()) {
530     return false;
531   }
532 
533   // Structure types are passed in register if all fields would be
534   // passed in a register.
535   for (RecordDecl::field_iterator i = RT->getDecl()->field_begin(),
536          e = RT->getDecl()->field_end(); i != e; ++i) {
537     const FieldDecl *FD = *i;
538 
539     // Empty fields are ignored.
540     if (isEmptyField(Context, FD, true))
541       continue;
542 
543     // Check fields recursively.
544     if (!shouldReturnTypeInRegister(FD->getType(), Context,
545                                     callingConvention))
546       return false;
547   }
548   return true;
549 }
550 
551 ABIArgInfo X86_32ABIInfo::classifyReturnType(QualType RetTy,
552                                             unsigned callingConvention) const {
553   if (RetTy->isVoidType())
554     return ABIArgInfo::getIgnore();
555 
556   if (const VectorType *VT = RetTy->getAs<VectorType>()) {
557     // On Darwin, some vectors are returned in registers.
558     if (IsDarwinVectorABI) {
559       uint64_t Size = getContext().getTypeSize(RetTy);
560 
561       // 128-bit vectors are a special case; they are returned in
562       // registers and we need to make sure to pick a type the LLVM
563       // backend will like.
564       if (Size == 128)
565         return ABIArgInfo::getDirect(llvm::VectorType::get(
566                   llvm::Type::getInt64Ty(getVMContext()), 2));
567 
568       // Always return in register if it fits in a general purpose
569       // register, or if it is 64 bits and has a single element.
570       if ((Size == 8 || Size == 16 || Size == 32) ||
571           (Size == 64 && VT->getNumElements() == 1))
572         return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),
573                                                             Size));
574 
575       return ABIArgInfo::getIndirect(0);
576     }
577 
578     return ABIArgInfo::getDirect();
579   }
580 
581   if (isAggregateTypeForABI(RetTy)) {
582     if (const RecordType *RT = RetTy->getAs<RecordType>()) {
583       // Structures with either a non-trivial destructor or a non-trivial
584       // copy constructor are always indirect.
585       if (hasNonTrivialDestructorOrCopyConstructor(RT))
586         return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
587 
588       // Structures with flexible arrays are always indirect.
589       if (RT->getDecl()->hasFlexibleArrayMember())
590         return ABIArgInfo::getIndirect(0);
591     }
592 
593     // If specified, structs and unions are always indirect.
594     if (!IsSmallStructInRegABI && !RetTy->isAnyComplexType())
595       return ABIArgInfo::getIndirect(0);
596 
597     // Small structures which are register sized are generally returned
598     // in a register.
599     if (X86_32ABIInfo::shouldReturnTypeInRegister(RetTy, getContext(),
600                                                   callingConvention)) {
601       uint64_t Size = getContext().getTypeSize(RetTy);
602 
603       // As a special-case, if the struct is a "single-element" struct, and
604       // the field is of type "float" or "double", return it in a
605       // floating-point register. (MSVC does not apply this special case.)
606       // We apply a similar transformation for pointer types to improve the
607       // quality of the generated IR.
608       if (const Type *SeltTy = isSingleElementStruct(RetTy, getContext()))
609         if ((!IsWin32FloatStructABI && SeltTy->isRealFloatingType())
610             || SeltTy->hasPointerRepresentation())
611           return ABIArgInfo::getDirect(CGT.ConvertType(QualType(SeltTy, 0)));
612 
613       // FIXME: We should be able to narrow this integer in cases with dead
614       // padding.
615       return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),Size));
616     }
617 
618     return ABIArgInfo::getIndirect(0);
619   }
620 
621   // Treat an enum type as its underlying type.
622   if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
623     RetTy = EnumTy->getDecl()->getIntegerType();
624 
625   return (RetTy->isPromotableIntegerType() ?
626           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
627 }
628 
629 static bool isSSEVectorType(ASTContext &Context, QualType Ty) {
630   return Ty->getAs<VectorType>() && Context.getTypeSize(Ty) == 128;
631 }
632 
633 static bool isRecordWithSSEVectorType(ASTContext &Context, QualType Ty) {
634   const RecordType *RT = Ty->getAs<RecordType>();
635   if (!RT)
636     return 0;
637   const RecordDecl *RD = RT->getDecl();
638 
639   // If this is a C++ record, check the bases first.
640   if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD))
641     for (CXXRecordDecl::base_class_const_iterator i = CXXRD->bases_begin(),
642            e = CXXRD->bases_end(); i != e; ++i)
643       if (!isRecordWithSSEVectorType(Context, i->getType()))
644         return false;
645 
646   for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
647        i != e; ++i) {
648     QualType FT = i->getType();
649 
650     if (isSSEVectorType(Context, FT))
651       return true;
652 
653     if (isRecordWithSSEVectorType(Context, FT))
654       return true;
655   }
656 
657   return false;
658 }
659 
660 unsigned X86_32ABIInfo::getTypeStackAlignInBytes(QualType Ty,
661                                                  unsigned Align) const {
662   // Otherwise, if the alignment is less than or equal to the minimum ABI
663   // alignment, just use the default; the backend will handle this.
664   if (Align <= MinABIStackAlignInBytes)
665     return 0; // Use default alignment.
666 
667   // On non-Darwin, the stack type alignment is always 4.
668   if (!IsDarwinVectorABI) {
669     // Set explicit alignment, since we may need to realign the top.
670     return MinABIStackAlignInBytes;
671   }
672 
673   // Otherwise, if the type contains an SSE vector type, the alignment is 16.
674   if (Align >= 16 && (isSSEVectorType(getContext(), Ty) ||
675                       isRecordWithSSEVectorType(getContext(), Ty)))
676     return 16;
677 
678   return MinABIStackAlignInBytes;
679 }
680 
681 ABIArgInfo X86_32ABIInfo::getIndirectResult(QualType Ty, bool ByVal) const {
682   if (!ByVal)
683     return ABIArgInfo::getIndirect(0, false);
684 
685   // Compute the byval alignment.
686   unsigned TypeAlign = getContext().getTypeAlign(Ty) / 8;
687   unsigned StackAlign = getTypeStackAlignInBytes(Ty, TypeAlign);
688   if (StackAlign == 0)
689     return ABIArgInfo::getIndirect(4);
690 
691   // If the stack alignment is less than the type alignment, realign the
692   // argument.
693   if (StackAlign < TypeAlign)
694     return ABIArgInfo::getIndirect(StackAlign, /*ByVal=*/true,
695                                    /*Realign=*/true);
696 
697   return ABIArgInfo::getIndirect(StackAlign);
698 }
699 
700 ABIArgInfo X86_32ABIInfo::classifyArgumentType(QualType Ty) const {
701   // FIXME: Set alignment on indirect arguments.
702   if (isAggregateTypeForABI(Ty)) {
703     // Structures with flexible arrays are always indirect.
704     if (const RecordType *RT = Ty->getAs<RecordType>()) {
705       // Structures with either a non-trivial destructor or a non-trivial
706       // copy constructor are always indirect.
707       if (hasNonTrivialDestructorOrCopyConstructor(RT))
708         return getIndirectResult(Ty, /*ByVal=*/false);
709 
710       if (RT->getDecl()->hasFlexibleArrayMember())
711         return getIndirectResult(Ty);
712     }
713 
714     // Ignore empty structs/unions.
715     if (isEmptyRecord(getContext(), Ty, true))
716       return ABIArgInfo::getIgnore();
717 
718     // Expand small (<= 128-bit) record types when we know that the stack layout
719     // of those arguments will match the struct. This is important because the
720     // LLVM backend isn't smart enough to remove byval, which inhibits many
721     // optimizations.
722     if (getContext().getTypeSize(Ty) <= 4*32 &&
723         canExpandIndirectArgument(Ty, getContext()))
724       return ABIArgInfo::getExpand();
725 
726     return getIndirectResult(Ty);
727   }
728 
729   if (const VectorType *VT = Ty->getAs<VectorType>()) {
730     // On Darwin, some vectors are passed in memory, we handle this by passing
731     // it as an i8/i16/i32/i64.
732     if (IsDarwinVectorABI) {
733       uint64_t Size = getContext().getTypeSize(Ty);
734       if ((Size == 8 || Size == 16 || Size == 32) ||
735           (Size == 64 && VT->getNumElements() == 1))
736         return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),
737                                                             Size));
738     }
739 
740     llvm::Type *IRType = CGT.ConvertType(Ty);
741     if (UseX86_MMXType(IRType)) {
742       if (IsMMXDisabled)
743         return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),
744                                                             64));
745       ABIArgInfo AAI = ABIArgInfo::getDirect(IRType);
746       AAI.setCoerceToType(llvm::Type::getX86_MMXTy(getVMContext()));
747       return AAI;
748     }
749 
750     return ABIArgInfo::getDirect();
751   }
752 
753 
754   if (const EnumType *EnumTy = Ty->getAs<EnumType>())
755     Ty = EnumTy->getDecl()->getIntegerType();
756 
757   return (Ty->isPromotableIntegerType() ?
758           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
759 }
760 
761 llvm::Value *X86_32ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
762                                       CodeGenFunction &CGF) const {
763   llvm::Type *BPP = CGF.Int8PtrPtrTy;
764 
765   CGBuilderTy &Builder = CGF.Builder;
766   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP,
767                                                        "ap");
768   llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
769 
770   // Compute if the address needs to be aligned
771   unsigned Align = CGF.getContext().getTypeAlignInChars(Ty).getQuantity();
772   Align = getTypeStackAlignInBytes(Ty, Align);
773   Align = std::max(Align, 4U);
774   if (Align > 4) {
775     // addr = (addr + align - 1) & -align;
776     llvm::Value *Offset =
777       llvm::ConstantInt::get(CGF.Int32Ty, Align - 1);
778     Addr = CGF.Builder.CreateGEP(Addr, Offset);
779     llvm::Value *AsInt = CGF.Builder.CreatePtrToInt(Addr,
780                                                     CGF.Int32Ty);
781     llvm::Value *Mask = llvm::ConstantInt::get(CGF.Int32Ty, -Align);
782     Addr = CGF.Builder.CreateIntToPtr(CGF.Builder.CreateAnd(AsInt, Mask),
783                                       Addr->getType(),
784                                       "ap.cur.aligned");
785   }
786 
787   llvm::Type *PTy =
788     llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
789   llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy);
790 
791   uint64_t Offset =
792     llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, Align);
793   llvm::Value *NextAddr =
794     Builder.CreateGEP(Addr, llvm::ConstantInt::get(CGF.Int32Ty, Offset),
795                       "ap.next");
796   Builder.CreateStore(NextAddr, VAListAddrAsBPP);
797 
798   return AddrTyped;
799 }
800 
801 void X86_32TargetCodeGenInfo::SetTargetAttributes(const Decl *D,
802                                                   llvm::GlobalValue *GV,
803                                             CodeGen::CodeGenModule &CGM) const {
804   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
805     if (FD->hasAttr<X86ForceAlignArgPointerAttr>()) {
806       // Get the LLVM function.
807       llvm::Function *Fn = cast<llvm::Function>(GV);
808 
809       // Now add the 'alignstack' attribute with a value of 16.
810       Fn->addFnAttr(llvm::Attribute::constructStackAlignmentFromInt(16));
811     }
812   }
813 }
814 
815 bool X86_32TargetCodeGenInfo::initDwarfEHRegSizeTable(
816                                                CodeGen::CodeGenFunction &CGF,
817                                                llvm::Value *Address) const {
818   CodeGen::CGBuilderTy &Builder = CGF.Builder;
819 
820   llvm::Value *Four8 = llvm::ConstantInt::get(CGF.Int8Ty, 4);
821 
822   // 0-7 are the eight integer registers;  the order is different
823   //   on Darwin (for EH), but the range is the same.
824   // 8 is %eip.
825   AssignToArrayRange(Builder, Address, Four8, 0, 8);
826 
827   if (CGF.CGM.isTargetDarwin()) {
828     // 12-16 are st(0..4).  Not sure why we stop at 4.
829     // These have size 16, which is sizeof(long double) on
830     // platforms with 8-byte alignment for that type.
831     llvm::Value *Sixteen8 = llvm::ConstantInt::get(CGF.Int8Ty, 16);
832     AssignToArrayRange(Builder, Address, Sixteen8, 12, 16);
833 
834   } else {
835     // 9 is %eflags, which doesn't get a size on Darwin for some
836     // reason.
837     Builder.CreateStore(Four8, Builder.CreateConstInBoundsGEP1_32(Address, 9));
838 
839     // 11-16 are st(0..5).  Not sure why we stop at 5.
840     // These have size 12, which is sizeof(long double) on
841     // platforms with 4-byte alignment for that type.
842     llvm::Value *Twelve8 = llvm::ConstantInt::get(CGF.Int8Ty, 12);
843     AssignToArrayRange(Builder, Address, Twelve8, 11, 16);
844   }
845 
846   return false;
847 }
848 
849 //===----------------------------------------------------------------------===//
850 // X86-64 ABI Implementation
851 //===----------------------------------------------------------------------===//
852 
853 
854 namespace {
855 /// X86_64ABIInfo - The X86_64 ABI information.
856 class X86_64ABIInfo : public ABIInfo {
857   enum Class {
858     Integer = 0,
859     SSE,
860     SSEUp,
861     X87,
862     X87Up,
863     ComplexX87,
864     NoClass,
865     Memory
866   };
867 
868   /// merge - Implement the X86_64 ABI merging algorithm.
869   ///
870   /// Merge an accumulating classification \arg Accum with a field
871   /// classification \arg Field.
872   ///
873   /// \param Accum - The accumulating classification. This should
874   /// always be either NoClass or the result of a previous merge
875   /// call. In addition, this should never be Memory (the caller
876   /// should just return Memory for the aggregate).
877   static Class merge(Class Accum, Class Field);
878 
879   /// postMerge - Implement the X86_64 ABI post merging algorithm.
880   ///
881   /// Post merger cleanup, reduces a malformed Hi and Lo pair to
882   /// final MEMORY or SSE classes when necessary.
883   ///
884   /// \param AggregateSize - The size of the current aggregate in
885   /// the classification process.
886   ///
887   /// \param Lo - The classification for the parts of the type
888   /// residing in the low word of the containing object.
889   ///
890   /// \param Hi - The classification for the parts of the type
891   /// residing in the higher words of the containing object.
892   ///
893   void postMerge(unsigned AggregateSize, Class &Lo, Class &Hi) const;
894 
895   /// classify - Determine the x86_64 register classes in which the
896   /// given type T should be passed.
897   ///
898   /// \param Lo - The classification for the parts of the type
899   /// residing in the low word of the containing object.
900   ///
901   /// \param Hi - The classification for the parts of the type
902   /// residing in the high word of the containing object.
903   ///
904   /// \param OffsetBase - The bit offset of this type in the
905   /// containing object.  Some parameters are classified different
906   /// depending on whether they straddle an eightbyte boundary.
907   ///
908   /// If a word is unused its result will be NoClass; if a type should
909   /// be passed in Memory then at least the classification of \arg Lo
910   /// will be Memory.
911   ///
912   /// The \arg Lo class will be NoClass iff the argument is ignored.
913   ///
914   /// If the \arg Lo class is ComplexX87, then the \arg Hi class will
915   /// also be ComplexX87.
916   void classify(QualType T, uint64_t OffsetBase, Class &Lo, Class &Hi) const;
917 
918   llvm::Type *GetByteVectorType(QualType Ty) const;
919   llvm::Type *GetSSETypeAtOffset(llvm::Type *IRType,
920                                  unsigned IROffset, QualType SourceTy,
921                                  unsigned SourceOffset) const;
922   llvm::Type *GetINTEGERTypeAtOffset(llvm::Type *IRType,
923                                      unsigned IROffset, QualType SourceTy,
924                                      unsigned SourceOffset) const;
925 
926   /// getIndirectResult - Give a source type \arg Ty, return a suitable result
927   /// such that the argument will be returned in memory.
928   ABIArgInfo getIndirectReturnResult(QualType Ty) const;
929 
930   /// getIndirectResult - Give a source type \arg Ty, return a suitable result
931   /// such that the argument will be passed in memory.
932   ///
933   /// \param freeIntRegs - The number of free integer registers remaining
934   /// available.
935   ABIArgInfo getIndirectResult(QualType Ty, unsigned freeIntRegs) const;
936 
937   ABIArgInfo classifyReturnType(QualType RetTy) const;
938 
939   ABIArgInfo classifyArgumentType(QualType Ty,
940                                   unsigned freeIntRegs,
941                                   unsigned &neededInt,
942                                   unsigned &neededSSE) const;
943 
944   bool IsIllegalVectorType(QualType Ty) const;
945 
946   /// The 0.98 ABI revision clarified a lot of ambiguities,
947   /// unfortunately in ways that were not always consistent with
948   /// certain previous compilers.  In particular, platforms which
949   /// required strict binary compatibility with older versions of GCC
950   /// may need to exempt themselves.
951   bool honorsRevision0_98() const {
952     return !getContext().getTargetInfo().getTriple().isOSDarwin();
953   }
954 
955   bool HasAVX;
956 
957 public:
958   X86_64ABIInfo(CodeGen::CodeGenTypes &CGT, bool hasavx) :
959       ABIInfo(CGT), HasAVX(hasavx) {}
960 
961   bool isPassedUsingAVXType(QualType type) const {
962     unsigned neededInt, neededSSE;
963     // The freeIntRegs argument doesn't matter here.
964     ABIArgInfo info = classifyArgumentType(type, 0, neededInt, neededSSE);
965     if (info.isDirect()) {
966       llvm::Type *ty = info.getCoerceToType();
967       if (llvm::VectorType *vectorTy = dyn_cast_or_null<llvm::VectorType>(ty))
968         return (vectorTy->getBitWidth() > 128);
969     }
970     return false;
971   }
972 
973   virtual void computeInfo(CGFunctionInfo &FI) const;
974 
975   virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
976                                  CodeGenFunction &CGF) const;
977 };
978 
979 /// WinX86_64ABIInfo - The Windows X86_64 ABI information.
980 class WinX86_64ABIInfo : public ABIInfo {
981 
982   ABIArgInfo classify(QualType Ty) const;
983 
984 public:
985   WinX86_64ABIInfo(CodeGen::CodeGenTypes &CGT) : ABIInfo(CGT) {}
986 
987   virtual void computeInfo(CGFunctionInfo &FI) const;
988 
989   virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
990                                  CodeGenFunction &CGF) const;
991 };
992 
993 class X86_64TargetCodeGenInfo : public TargetCodeGenInfo {
994 public:
995   X86_64TargetCodeGenInfo(CodeGen::CodeGenTypes &CGT, bool HasAVX)
996     : TargetCodeGenInfo(new X86_64ABIInfo(CGT, HasAVX)) {}
997 
998   const X86_64ABIInfo &getABIInfo() const {
999     return static_cast<const X86_64ABIInfo&>(TargetCodeGenInfo::getABIInfo());
1000   }
1001 
1002   int getDwarfEHStackPointer(CodeGen::CodeGenModule &CGM) const {
1003     return 7;
1004   }
1005 
1006   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
1007                                llvm::Value *Address) const {
1008     llvm::Value *Eight8 = llvm::ConstantInt::get(CGF.Int8Ty, 8);
1009 
1010     // 0-15 are the 16 integer registers.
1011     // 16 is %rip.
1012     AssignToArrayRange(CGF.Builder, Address, Eight8, 0, 16);
1013     return false;
1014   }
1015 
1016   llvm::Type* adjustInlineAsmType(CodeGen::CodeGenFunction &CGF,
1017                                   StringRef Constraint,
1018                                   llvm::Type* Ty) const {
1019     return X86AdjustInlineAsmType(CGF, Constraint, Ty);
1020   }
1021 
1022   bool isNoProtoCallVariadic(const CallArgList &args,
1023                              const FunctionNoProtoType *fnType) const {
1024     // The default CC on x86-64 sets %al to the number of SSA
1025     // registers used, and GCC sets this when calling an unprototyped
1026     // function, so we override the default behavior.  However, don't do
1027     // that when AVX types are involved: the ABI explicitly states it is
1028     // undefined, and it doesn't work in practice because of how the ABI
1029     // defines varargs anyway.
1030     if (fnType->getCallConv() == CC_Default || fnType->getCallConv() == CC_C) {
1031       bool HasAVXType = false;
1032       for (CallArgList::const_iterator
1033              it = args.begin(), ie = args.end(); it != ie; ++it) {
1034         if (getABIInfo().isPassedUsingAVXType(it->Ty)) {
1035           HasAVXType = true;
1036           break;
1037         }
1038       }
1039 
1040       if (!HasAVXType)
1041         return true;
1042     }
1043 
1044     return TargetCodeGenInfo::isNoProtoCallVariadic(args, fnType);
1045   }
1046 
1047 };
1048 
1049 class WinX86_64TargetCodeGenInfo : public TargetCodeGenInfo {
1050 public:
1051   WinX86_64TargetCodeGenInfo(CodeGen::CodeGenTypes &CGT)
1052     : TargetCodeGenInfo(new WinX86_64ABIInfo(CGT)) {}
1053 
1054   int getDwarfEHStackPointer(CodeGen::CodeGenModule &CGM) const {
1055     return 7;
1056   }
1057 
1058   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
1059                                llvm::Value *Address) const {
1060     llvm::Value *Eight8 = llvm::ConstantInt::get(CGF.Int8Ty, 8);
1061 
1062     // 0-15 are the 16 integer registers.
1063     // 16 is %rip.
1064     AssignToArrayRange(CGF.Builder, Address, Eight8, 0, 16);
1065     return false;
1066   }
1067 };
1068 
1069 }
1070 
1071 void X86_64ABIInfo::postMerge(unsigned AggregateSize, Class &Lo,
1072                               Class &Hi) const {
1073   // AMD64-ABI 3.2.3p2: Rule 5. Then a post merger cleanup is done:
1074   //
1075   // (a) If one of the classes is Memory, the whole argument is passed in
1076   //     memory.
1077   //
1078   // (b) If X87UP is not preceded by X87, the whole argument is passed in
1079   //     memory.
1080   //
1081   // (c) If the size of the aggregate exceeds two eightbytes and the first
1082   //     eightbyte isn't SSE or any other eightbyte isn't SSEUP, the whole
1083   //     argument is passed in memory. NOTE: This is necessary to keep the
1084   //     ABI working for processors that don't support the __m256 type.
1085   //
1086   // (d) If SSEUP is not preceded by SSE or SSEUP, it is converted to SSE.
1087   //
1088   // Some of these are enforced by the merging logic.  Others can arise
1089   // only with unions; for example:
1090   //   union { _Complex double; unsigned; }
1091   //
1092   // Note that clauses (b) and (c) were added in 0.98.
1093   //
1094   if (Hi == Memory)
1095     Lo = Memory;
1096   if (Hi == X87Up && Lo != X87 && honorsRevision0_98())
1097     Lo = Memory;
1098   if (AggregateSize > 128 && (Lo != SSE || Hi != SSEUp))
1099     Lo = Memory;
1100   if (Hi == SSEUp && Lo != SSE)
1101     Hi = SSE;
1102 }
1103 
1104 X86_64ABIInfo::Class X86_64ABIInfo::merge(Class Accum, Class Field) {
1105   // AMD64-ABI 3.2.3p2: Rule 4. Each field of an object is
1106   // classified recursively so that always two fields are
1107   // considered. The resulting class is calculated according to
1108   // the classes of the fields in the eightbyte:
1109   //
1110   // (a) If both classes are equal, this is the resulting class.
1111   //
1112   // (b) If one of the classes is NO_CLASS, the resulting class is
1113   // the other class.
1114   //
1115   // (c) If one of the classes is MEMORY, the result is the MEMORY
1116   // class.
1117   //
1118   // (d) If one of the classes is INTEGER, the result is the
1119   // INTEGER.
1120   //
1121   // (e) If one of the classes is X87, X87UP, COMPLEX_X87 class,
1122   // MEMORY is used as class.
1123   //
1124   // (f) Otherwise class SSE is used.
1125 
1126   // Accum should never be memory (we should have returned) or
1127   // ComplexX87 (because this cannot be passed in a structure).
1128   assert((Accum != Memory && Accum != ComplexX87) &&
1129          "Invalid accumulated classification during merge.");
1130   if (Accum == Field || Field == NoClass)
1131     return Accum;
1132   if (Field == Memory)
1133     return Memory;
1134   if (Accum == NoClass)
1135     return Field;
1136   if (Accum == Integer || Field == Integer)
1137     return Integer;
1138   if (Field == X87 || Field == X87Up || Field == ComplexX87 ||
1139       Accum == X87 || Accum == X87Up)
1140     return Memory;
1141   return SSE;
1142 }
1143 
1144 void X86_64ABIInfo::classify(QualType Ty, uint64_t OffsetBase,
1145                              Class &Lo, Class &Hi) const {
1146   // FIXME: This code can be simplified by introducing a simple value class for
1147   // Class pairs with appropriate constructor methods for the various
1148   // situations.
1149 
1150   // FIXME: Some of the split computations are wrong; unaligned vectors
1151   // shouldn't be passed in registers for example, so there is no chance they
1152   // can straddle an eightbyte. Verify & simplify.
1153 
1154   Lo = Hi = NoClass;
1155 
1156   Class &Current = OffsetBase < 64 ? Lo : Hi;
1157   Current = Memory;
1158 
1159   if (const BuiltinType *BT = Ty->getAs<BuiltinType>()) {
1160     BuiltinType::Kind k = BT->getKind();
1161 
1162     if (k == BuiltinType::Void) {
1163       Current = NoClass;
1164     } else if (k == BuiltinType::Int128 || k == BuiltinType::UInt128) {
1165       Lo = Integer;
1166       Hi = Integer;
1167     } else if (k >= BuiltinType::Bool && k <= BuiltinType::LongLong) {
1168       Current = Integer;
1169     } else if (k == BuiltinType::Float || k == BuiltinType::Double) {
1170       Current = SSE;
1171     } else if (k == BuiltinType::LongDouble) {
1172       Lo = X87;
1173       Hi = X87Up;
1174     }
1175     // FIXME: _Decimal32 and _Decimal64 are SSE.
1176     // FIXME: _float128 and _Decimal128 are (SSE, SSEUp).
1177     return;
1178   }
1179 
1180   if (const EnumType *ET = Ty->getAs<EnumType>()) {
1181     // Classify the underlying integer type.
1182     classify(ET->getDecl()->getIntegerType(), OffsetBase, Lo, Hi);
1183     return;
1184   }
1185 
1186   if (Ty->hasPointerRepresentation()) {
1187     Current = Integer;
1188     return;
1189   }
1190 
1191   if (Ty->isMemberPointerType()) {
1192     if (Ty->isMemberFunctionPointerType())
1193       Lo = Hi = Integer;
1194     else
1195       Current = Integer;
1196     return;
1197   }
1198 
1199   if (const VectorType *VT = Ty->getAs<VectorType>()) {
1200     uint64_t Size = getContext().getTypeSize(VT);
1201     if (Size == 32) {
1202       // gcc passes all <4 x char>, <2 x short>, <1 x int>, <1 x
1203       // float> as integer.
1204       Current = Integer;
1205 
1206       // If this type crosses an eightbyte boundary, it should be
1207       // split.
1208       uint64_t EB_Real = (OffsetBase) / 64;
1209       uint64_t EB_Imag = (OffsetBase + Size - 1) / 64;
1210       if (EB_Real != EB_Imag)
1211         Hi = Lo;
1212     } else if (Size == 64) {
1213       // gcc passes <1 x double> in memory. :(
1214       if (VT->getElementType()->isSpecificBuiltinType(BuiltinType::Double))
1215         return;
1216 
1217       // gcc passes <1 x long long> as INTEGER.
1218       if (VT->getElementType()->isSpecificBuiltinType(BuiltinType::LongLong) ||
1219           VT->getElementType()->isSpecificBuiltinType(BuiltinType::ULongLong) ||
1220           VT->getElementType()->isSpecificBuiltinType(BuiltinType::Long) ||
1221           VT->getElementType()->isSpecificBuiltinType(BuiltinType::ULong))
1222         Current = Integer;
1223       else
1224         Current = SSE;
1225 
1226       // If this type crosses an eightbyte boundary, it should be
1227       // split.
1228       if (OffsetBase && OffsetBase != 64)
1229         Hi = Lo;
1230     } else if (Size == 128 || (HasAVX && Size == 256)) {
1231       // Arguments of 256-bits are split into four eightbyte chunks. The
1232       // least significant one belongs to class SSE and all the others to class
1233       // SSEUP. The original Lo and Hi design considers that types can't be
1234       // greater than 128-bits, so a 64-bit split in Hi and Lo makes sense.
1235       // This design isn't correct for 256-bits, but since there're no cases
1236       // where the upper parts would need to be inspected, avoid adding
1237       // complexity and just consider Hi to match the 64-256 part.
1238       Lo = SSE;
1239       Hi = SSEUp;
1240     }
1241     return;
1242   }
1243 
1244   if (const ComplexType *CT = Ty->getAs<ComplexType>()) {
1245     QualType ET = getContext().getCanonicalType(CT->getElementType());
1246 
1247     uint64_t Size = getContext().getTypeSize(Ty);
1248     if (ET->isIntegralOrEnumerationType()) {
1249       if (Size <= 64)
1250         Current = Integer;
1251       else if (Size <= 128)
1252         Lo = Hi = Integer;
1253     } else if (ET == getContext().FloatTy)
1254       Current = SSE;
1255     else if (ET == getContext().DoubleTy)
1256       Lo = Hi = SSE;
1257     else if (ET == getContext().LongDoubleTy)
1258       Current = ComplexX87;
1259 
1260     // If this complex type crosses an eightbyte boundary then it
1261     // should be split.
1262     uint64_t EB_Real = (OffsetBase) / 64;
1263     uint64_t EB_Imag = (OffsetBase + getContext().getTypeSize(ET)) / 64;
1264     if (Hi == NoClass && EB_Real != EB_Imag)
1265       Hi = Lo;
1266 
1267     return;
1268   }
1269 
1270   if (const ConstantArrayType *AT = getContext().getAsConstantArrayType(Ty)) {
1271     // Arrays are treated like structures.
1272 
1273     uint64_t Size = getContext().getTypeSize(Ty);
1274 
1275     // AMD64-ABI 3.2.3p2: Rule 1. If the size of an object is larger
1276     // than four eightbytes, ..., it has class MEMORY.
1277     if (Size > 256)
1278       return;
1279 
1280     // AMD64-ABI 3.2.3p2: Rule 1. If ..., or it contains unaligned
1281     // fields, it has class MEMORY.
1282     //
1283     // Only need to check alignment of array base.
1284     if (OffsetBase % getContext().getTypeAlign(AT->getElementType()))
1285       return;
1286 
1287     // Otherwise implement simplified merge. We could be smarter about
1288     // this, but it isn't worth it and would be harder to verify.
1289     Current = NoClass;
1290     uint64_t EltSize = getContext().getTypeSize(AT->getElementType());
1291     uint64_t ArraySize = AT->getSize().getZExtValue();
1292 
1293     // The only case a 256-bit wide vector could be used is when the array
1294     // contains a single 256-bit element. Since Lo and Hi logic isn't extended
1295     // to work for sizes wider than 128, early check and fallback to memory.
1296     if (Size > 128 && EltSize != 256)
1297       return;
1298 
1299     for (uint64_t i=0, Offset=OffsetBase; i<ArraySize; ++i, Offset += EltSize) {
1300       Class FieldLo, FieldHi;
1301       classify(AT->getElementType(), Offset, FieldLo, FieldHi);
1302       Lo = merge(Lo, FieldLo);
1303       Hi = merge(Hi, FieldHi);
1304       if (Lo == Memory || Hi == Memory)
1305         break;
1306     }
1307 
1308     postMerge(Size, Lo, Hi);
1309     assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp array classification.");
1310     return;
1311   }
1312 
1313   if (const RecordType *RT = Ty->getAs<RecordType>()) {
1314     uint64_t Size = getContext().getTypeSize(Ty);
1315 
1316     // AMD64-ABI 3.2.3p2: Rule 1. If the size of an object is larger
1317     // than four eightbytes, ..., it has class MEMORY.
1318     if (Size > 256)
1319       return;
1320 
1321     // AMD64-ABI 3.2.3p2: Rule 2. If a C++ object has either a non-trivial
1322     // copy constructor or a non-trivial destructor, it is passed by invisible
1323     // reference.
1324     if (hasNonTrivialDestructorOrCopyConstructor(RT))
1325       return;
1326 
1327     const RecordDecl *RD = RT->getDecl();
1328 
1329     // Assume variable sized types are passed in memory.
1330     if (RD->hasFlexibleArrayMember())
1331       return;
1332 
1333     const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
1334 
1335     // Reset Lo class, this will be recomputed.
1336     Current = NoClass;
1337 
1338     // If this is a C++ record, classify the bases first.
1339     if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
1340       for (CXXRecordDecl::base_class_const_iterator i = CXXRD->bases_begin(),
1341              e = CXXRD->bases_end(); i != e; ++i) {
1342         assert(!i->isVirtual() && !i->getType()->isDependentType() &&
1343                "Unexpected base class!");
1344         const CXXRecordDecl *Base =
1345           cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
1346 
1347         // Classify this field.
1348         //
1349         // AMD64-ABI 3.2.3p2: Rule 3. If the size of the aggregate exceeds a
1350         // single eightbyte, each is classified separately. Each eightbyte gets
1351         // initialized to class NO_CLASS.
1352         Class FieldLo, FieldHi;
1353         uint64_t Offset =
1354           OffsetBase + getContext().toBits(Layout.getBaseClassOffset(Base));
1355         classify(i->getType(), Offset, FieldLo, FieldHi);
1356         Lo = merge(Lo, FieldLo);
1357         Hi = merge(Hi, FieldHi);
1358         if (Lo == Memory || Hi == Memory)
1359           break;
1360       }
1361     }
1362 
1363     // Classify the fields one at a time, merging the results.
1364     unsigned idx = 0;
1365     for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
1366            i != e; ++i, ++idx) {
1367       uint64_t Offset = OffsetBase + Layout.getFieldOffset(idx);
1368       bool BitField = i->isBitField();
1369 
1370       // AMD64-ABI 3.2.3p2: Rule 1. If the size of an object is larger than
1371       // four eightbytes, or it contains unaligned fields, it has class MEMORY.
1372       //
1373       // The only case a 256-bit wide vector could be used is when the struct
1374       // contains a single 256-bit element. Since Lo and Hi logic isn't extended
1375       // to work for sizes wider than 128, early check and fallback to memory.
1376       //
1377       if (Size > 128 && getContext().getTypeSize(i->getType()) != 256) {
1378         Lo = Memory;
1379         return;
1380       }
1381       // Note, skip this test for bit-fields, see below.
1382       if (!BitField && Offset % getContext().getTypeAlign(i->getType())) {
1383         Lo = Memory;
1384         return;
1385       }
1386 
1387       // Classify this field.
1388       //
1389       // AMD64-ABI 3.2.3p2: Rule 3. If the size of the aggregate
1390       // exceeds a single eightbyte, each is classified
1391       // separately. Each eightbyte gets initialized to class
1392       // NO_CLASS.
1393       Class FieldLo, FieldHi;
1394 
1395       // Bit-fields require special handling, they do not force the
1396       // structure to be passed in memory even if unaligned, and
1397       // therefore they can straddle an eightbyte.
1398       if (BitField) {
1399         // Ignore padding bit-fields.
1400         if (i->isUnnamedBitfield())
1401           continue;
1402 
1403         uint64_t Offset = OffsetBase + Layout.getFieldOffset(idx);
1404         uint64_t Size = i->getBitWidthValue(getContext());
1405 
1406         uint64_t EB_Lo = Offset / 64;
1407         uint64_t EB_Hi = (Offset + Size - 1) / 64;
1408         FieldLo = FieldHi = NoClass;
1409         if (EB_Lo) {
1410           assert(EB_Hi == EB_Lo && "Invalid classification, type > 16 bytes.");
1411           FieldLo = NoClass;
1412           FieldHi = Integer;
1413         } else {
1414           FieldLo = Integer;
1415           FieldHi = EB_Hi ? Integer : NoClass;
1416         }
1417       } else
1418         classify(i->getType(), Offset, FieldLo, FieldHi);
1419       Lo = merge(Lo, FieldLo);
1420       Hi = merge(Hi, FieldHi);
1421       if (Lo == Memory || Hi == Memory)
1422         break;
1423     }
1424 
1425     postMerge(Size, Lo, Hi);
1426   }
1427 }
1428 
1429 ABIArgInfo X86_64ABIInfo::getIndirectReturnResult(QualType Ty) const {
1430   // If this is a scalar LLVM value then assume LLVM will pass it in the right
1431   // place naturally.
1432   if (!isAggregateTypeForABI(Ty)) {
1433     // Treat an enum type as its underlying type.
1434     if (const EnumType *EnumTy = Ty->getAs<EnumType>())
1435       Ty = EnumTy->getDecl()->getIntegerType();
1436 
1437     return (Ty->isPromotableIntegerType() ?
1438             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
1439   }
1440 
1441   return ABIArgInfo::getIndirect(0);
1442 }
1443 
1444 bool X86_64ABIInfo::IsIllegalVectorType(QualType Ty) const {
1445   if (const VectorType *VecTy = Ty->getAs<VectorType>()) {
1446     uint64_t Size = getContext().getTypeSize(VecTy);
1447     unsigned LargestVector = HasAVX ? 256 : 128;
1448     if (Size <= 64 || Size > LargestVector)
1449       return true;
1450   }
1451 
1452   return false;
1453 }
1454 
1455 ABIArgInfo X86_64ABIInfo::getIndirectResult(QualType Ty,
1456                                             unsigned freeIntRegs) const {
1457   // If this is a scalar LLVM value then assume LLVM will pass it in the right
1458   // place naturally.
1459   //
1460   // This assumption is optimistic, as there could be free registers available
1461   // when we need to pass this argument in memory, and LLVM could try to pass
1462   // the argument in the free register. This does not seem to happen currently,
1463   // but this code would be much safer if we could mark the argument with
1464   // 'onstack'. See PR12193.
1465   if (!isAggregateTypeForABI(Ty) && !IsIllegalVectorType(Ty)) {
1466     // Treat an enum type as its underlying type.
1467     if (const EnumType *EnumTy = Ty->getAs<EnumType>())
1468       Ty = EnumTy->getDecl()->getIntegerType();
1469 
1470     return (Ty->isPromotableIntegerType() ?
1471             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
1472   }
1473 
1474   if (isRecordWithNonTrivialDestructorOrCopyConstructor(Ty))
1475     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
1476 
1477   // Compute the byval alignment. We specify the alignment of the byval in all
1478   // cases so that the mid-level optimizer knows the alignment of the byval.
1479   unsigned Align = std::max(getContext().getTypeAlign(Ty) / 8, 8U);
1480 
1481   // Attempt to avoid passing indirect results using byval when possible. This
1482   // is important for good codegen.
1483   //
1484   // We do this by coercing the value into a scalar type which the backend can
1485   // handle naturally (i.e., without using byval).
1486   //
1487   // For simplicity, we currently only do this when we have exhausted all of the
1488   // free integer registers. Doing this when there are free integer registers
1489   // would require more care, as we would have to ensure that the coerced value
1490   // did not claim the unused register. That would require either reording the
1491   // arguments to the function (so that any subsequent inreg values came first),
1492   // or only doing this optimization when there were no following arguments that
1493   // might be inreg.
1494   //
1495   // We currently expect it to be rare (particularly in well written code) for
1496   // arguments to be passed on the stack when there are still free integer
1497   // registers available (this would typically imply large structs being passed
1498   // by value), so this seems like a fair tradeoff for now.
1499   //
1500   // We can revisit this if the backend grows support for 'onstack' parameter
1501   // attributes. See PR12193.
1502   if (freeIntRegs == 0) {
1503     uint64_t Size = getContext().getTypeSize(Ty);
1504 
1505     // If this type fits in an eightbyte, coerce it into the matching integral
1506     // type, which will end up on the stack (with alignment 8).
1507     if (Align == 8 && Size <= 64)
1508       return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),
1509                                                           Size));
1510   }
1511 
1512   return ABIArgInfo::getIndirect(Align);
1513 }
1514 
1515 /// GetByteVectorType - The ABI specifies that a value should be passed in an
1516 /// full vector XMM/YMM register.  Pick an LLVM IR type that will be passed as a
1517 /// vector register.
1518 llvm::Type *X86_64ABIInfo::GetByteVectorType(QualType Ty) const {
1519   llvm::Type *IRType = CGT.ConvertType(Ty);
1520 
1521   // Wrapper structs that just contain vectors are passed just like vectors,
1522   // strip them off if present.
1523   llvm::StructType *STy = dyn_cast<llvm::StructType>(IRType);
1524   while (STy && STy->getNumElements() == 1) {
1525     IRType = STy->getElementType(0);
1526     STy = dyn_cast<llvm::StructType>(IRType);
1527   }
1528 
1529   // If the preferred type is a 16-byte vector, prefer to pass it.
1530   if (llvm::VectorType *VT = dyn_cast<llvm::VectorType>(IRType)){
1531     llvm::Type *EltTy = VT->getElementType();
1532     unsigned BitWidth = VT->getBitWidth();
1533     if ((BitWidth >= 128 && BitWidth <= 256) &&
1534         (EltTy->isFloatTy() || EltTy->isDoubleTy() ||
1535          EltTy->isIntegerTy(8) || EltTy->isIntegerTy(16) ||
1536          EltTy->isIntegerTy(32) || EltTy->isIntegerTy(64) ||
1537          EltTy->isIntegerTy(128)))
1538       return VT;
1539   }
1540 
1541   return llvm::VectorType::get(llvm::Type::getDoubleTy(getVMContext()), 2);
1542 }
1543 
1544 /// BitsContainNoUserData - Return true if the specified [start,end) bit range
1545 /// is known to either be off the end of the specified type or being in
1546 /// alignment padding.  The user type specified is known to be at most 128 bits
1547 /// in size, and have passed through X86_64ABIInfo::classify with a successful
1548 /// classification that put one of the two halves in the INTEGER class.
1549 ///
1550 /// It is conservatively correct to return false.
1551 static bool BitsContainNoUserData(QualType Ty, unsigned StartBit,
1552                                   unsigned EndBit, ASTContext &Context) {
1553   // If the bytes being queried are off the end of the type, there is no user
1554   // data hiding here.  This handles analysis of builtins, vectors and other
1555   // types that don't contain interesting padding.
1556   unsigned TySize = (unsigned)Context.getTypeSize(Ty);
1557   if (TySize <= StartBit)
1558     return true;
1559 
1560   if (const ConstantArrayType *AT = Context.getAsConstantArrayType(Ty)) {
1561     unsigned EltSize = (unsigned)Context.getTypeSize(AT->getElementType());
1562     unsigned NumElts = (unsigned)AT->getSize().getZExtValue();
1563 
1564     // Check each element to see if the element overlaps with the queried range.
1565     for (unsigned i = 0; i != NumElts; ++i) {
1566       // If the element is after the span we care about, then we're done..
1567       unsigned EltOffset = i*EltSize;
1568       if (EltOffset >= EndBit) break;
1569 
1570       unsigned EltStart = EltOffset < StartBit ? StartBit-EltOffset :0;
1571       if (!BitsContainNoUserData(AT->getElementType(), EltStart,
1572                                  EndBit-EltOffset, Context))
1573         return false;
1574     }
1575     // If it overlaps no elements, then it is safe to process as padding.
1576     return true;
1577   }
1578 
1579   if (const RecordType *RT = Ty->getAs<RecordType>()) {
1580     const RecordDecl *RD = RT->getDecl();
1581     const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
1582 
1583     // If this is a C++ record, check the bases first.
1584     if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
1585       for (CXXRecordDecl::base_class_const_iterator i = CXXRD->bases_begin(),
1586            e = CXXRD->bases_end(); i != e; ++i) {
1587         assert(!i->isVirtual() && !i->getType()->isDependentType() &&
1588                "Unexpected base class!");
1589         const CXXRecordDecl *Base =
1590           cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
1591 
1592         // If the base is after the span we care about, ignore it.
1593         unsigned BaseOffset = Context.toBits(Layout.getBaseClassOffset(Base));
1594         if (BaseOffset >= EndBit) continue;
1595 
1596         unsigned BaseStart = BaseOffset < StartBit ? StartBit-BaseOffset :0;
1597         if (!BitsContainNoUserData(i->getType(), BaseStart,
1598                                    EndBit-BaseOffset, Context))
1599           return false;
1600       }
1601     }
1602 
1603     // Verify that no field has data that overlaps the region of interest.  Yes
1604     // this could be sped up a lot by being smarter about queried fields,
1605     // however we're only looking at structs up to 16 bytes, so we don't care
1606     // much.
1607     unsigned idx = 0;
1608     for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
1609          i != e; ++i, ++idx) {
1610       unsigned FieldOffset = (unsigned)Layout.getFieldOffset(idx);
1611 
1612       // If we found a field after the region we care about, then we're done.
1613       if (FieldOffset >= EndBit) break;
1614 
1615       unsigned FieldStart = FieldOffset < StartBit ? StartBit-FieldOffset :0;
1616       if (!BitsContainNoUserData(i->getType(), FieldStart, EndBit-FieldOffset,
1617                                  Context))
1618         return false;
1619     }
1620 
1621     // If nothing in this record overlapped the area of interest, then we're
1622     // clean.
1623     return true;
1624   }
1625 
1626   return false;
1627 }
1628 
1629 /// ContainsFloatAtOffset - Return true if the specified LLVM IR type has a
1630 /// float member at the specified offset.  For example, {int,{float}} has a
1631 /// float at offset 4.  It is conservatively correct for this routine to return
1632 /// false.
1633 static bool ContainsFloatAtOffset(llvm::Type *IRType, unsigned IROffset,
1634                                   const llvm::TargetData &TD) {
1635   // Base case if we find a float.
1636   if (IROffset == 0 && IRType->isFloatTy())
1637     return true;
1638 
1639   // If this is a struct, recurse into the field at the specified offset.
1640   if (llvm::StructType *STy = dyn_cast<llvm::StructType>(IRType)) {
1641     const llvm::StructLayout *SL = TD.getStructLayout(STy);
1642     unsigned Elt = SL->getElementContainingOffset(IROffset);
1643     IROffset -= SL->getElementOffset(Elt);
1644     return ContainsFloatAtOffset(STy->getElementType(Elt), IROffset, TD);
1645   }
1646 
1647   // If this is an array, recurse into the field at the specified offset.
1648   if (llvm::ArrayType *ATy = dyn_cast<llvm::ArrayType>(IRType)) {
1649     llvm::Type *EltTy = ATy->getElementType();
1650     unsigned EltSize = TD.getTypeAllocSize(EltTy);
1651     IROffset -= IROffset/EltSize*EltSize;
1652     return ContainsFloatAtOffset(EltTy, IROffset, TD);
1653   }
1654 
1655   return false;
1656 }
1657 
1658 
1659 /// GetSSETypeAtOffset - Return a type that will be passed by the backend in the
1660 /// low 8 bytes of an XMM register, corresponding to the SSE class.
1661 llvm::Type *X86_64ABIInfo::
1662 GetSSETypeAtOffset(llvm::Type *IRType, unsigned IROffset,
1663                    QualType SourceTy, unsigned SourceOffset) const {
1664   // The only three choices we have are either double, <2 x float>, or float. We
1665   // pass as float if the last 4 bytes is just padding.  This happens for
1666   // structs that contain 3 floats.
1667   if (BitsContainNoUserData(SourceTy, SourceOffset*8+32,
1668                             SourceOffset*8+64, getContext()))
1669     return llvm::Type::getFloatTy(getVMContext());
1670 
1671   // We want to pass as <2 x float> if the LLVM IR type contains a float at
1672   // offset+0 and offset+4.  Walk the LLVM IR type to find out if this is the
1673   // case.
1674   if (ContainsFloatAtOffset(IRType, IROffset, getTargetData()) &&
1675       ContainsFloatAtOffset(IRType, IROffset+4, getTargetData()))
1676     return llvm::VectorType::get(llvm::Type::getFloatTy(getVMContext()), 2);
1677 
1678   return llvm::Type::getDoubleTy(getVMContext());
1679 }
1680 
1681 
1682 /// GetINTEGERTypeAtOffset - The ABI specifies that a value should be passed in
1683 /// an 8-byte GPR.  This means that we either have a scalar or we are talking
1684 /// about the high or low part of an up-to-16-byte struct.  This routine picks
1685 /// the best LLVM IR type to represent this, which may be i64 or may be anything
1686 /// else that the backend will pass in a GPR that works better (e.g. i8, %foo*,
1687 /// etc).
1688 ///
1689 /// PrefType is an LLVM IR type that corresponds to (part of) the IR type for
1690 /// the source type.  IROffset is an offset in bytes into the LLVM IR type that
1691 /// the 8-byte value references.  PrefType may be null.
1692 ///
1693 /// SourceTy is the source level type for the entire argument.  SourceOffset is
1694 /// an offset into this that we're processing (which is always either 0 or 8).
1695 ///
1696 llvm::Type *X86_64ABIInfo::
1697 GetINTEGERTypeAtOffset(llvm::Type *IRType, unsigned IROffset,
1698                        QualType SourceTy, unsigned SourceOffset) const {
1699   // If we're dealing with an un-offset LLVM IR type, then it means that we're
1700   // returning an 8-byte unit starting with it.  See if we can safely use it.
1701   if (IROffset == 0) {
1702     // Pointers and int64's always fill the 8-byte unit.
1703     if (isa<llvm::PointerType>(IRType) || IRType->isIntegerTy(64))
1704       return IRType;
1705 
1706     // If we have a 1/2/4-byte integer, we can use it only if the rest of the
1707     // goodness in the source type is just tail padding.  This is allowed to
1708     // kick in for struct {double,int} on the int, but not on
1709     // struct{double,int,int} because we wouldn't return the second int.  We
1710     // have to do this analysis on the source type because we can't depend on
1711     // unions being lowered a specific way etc.
1712     if (IRType->isIntegerTy(8) || IRType->isIntegerTy(16) ||
1713         IRType->isIntegerTy(32)) {
1714       unsigned BitWidth = cast<llvm::IntegerType>(IRType)->getBitWidth();
1715 
1716       if (BitsContainNoUserData(SourceTy, SourceOffset*8+BitWidth,
1717                                 SourceOffset*8+64, getContext()))
1718         return IRType;
1719     }
1720   }
1721 
1722   if (llvm::StructType *STy = dyn_cast<llvm::StructType>(IRType)) {
1723     // If this is a struct, recurse into the field at the specified offset.
1724     const llvm::StructLayout *SL = getTargetData().getStructLayout(STy);
1725     if (IROffset < SL->getSizeInBytes()) {
1726       unsigned FieldIdx = SL->getElementContainingOffset(IROffset);
1727       IROffset -= SL->getElementOffset(FieldIdx);
1728 
1729       return GetINTEGERTypeAtOffset(STy->getElementType(FieldIdx), IROffset,
1730                                     SourceTy, SourceOffset);
1731     }
1732   }
1733 
1734   if (llvm::ArrayType *ATy = dyn_cast<llvm::ArrayType>(IRType)) {
1735     llvm::Type *EltTy = ATy->getElementType();
1736     unsigned EltSize = getTargetData().getTypeAllocSize(EltTy);
1737     unsigned EltOffset = IROffset/EltSize*EltSize;
1738     return GetINTEGERTypeAtOffset(EltTy, IROffset-EltOffset, SourceTy,
1739                                   SourceOffset);
1740   }
1741 
1742   // Okay, we don't have any better idea of what to pass, so we pass this in an
1743   // integer register that isn't too big to fit the rest of the struct.
1744   unsigned TySizeInBytes =
1745     (unsigned)getContext().getTypeSizeInChars(SourceTy).getQuantity();
1746 
1747   assert(TySizeInBytes != SourceOffset && "Empty field?");
1748 
1749   // It is always safe to classify this as an integer type up to i64 that
1750   // isn't larger than the structure.
1751   return llvm::IntegerType::get(getVMContext(),
1752                                 std::min(TySizeInBytes-SourceOffset, 8U)*8);
1753 }
1754 
1755 
1756 /// GetX86_64ByValArgumentPair - Given a high and low type that can ideally
1757 /// be used as elements of a two register pair to pass or return, return a
1758 /// first class aggregate to represent them.  For example, if the low part of
1759 /// a by-value argument should be passed as i32* and the high part as float,
1760 /// return {i32*, float}.
1761 static llvm::Type *
1762 GetX86_64ByValArgumentPair(llvm::Type *Lo, llvm::Type *Hi,
1763                            const llvm::TargetData &TD) {
1764   // In order to correctly satisfy the ABI, we need to the high part to start
1765   // at offset 8.  If the high and low parts we inferred are both 4-byte types
1766   // (e.g. i32 and i32) then the resultant struct type ({i32,i32}) won't have
1767   // the second element at offset 8.  Check for this:
1768   unsigned LoSize = (unsigned)TD.getTypeAllocSize(Lo);
1769   unsigned HiAlign = TD.getABITypeAlignment(Hi);
1770   unsigned HiStart = llvm::TargetData::RoundUpAlignment(LoSize, HiAlign);
1771   assert(HiStart != 0 && HiStart <= 8 && "Invalid x86-64 argument pair!");
1772 
1773   // To handle this, we have to increase the size of the low part so that the
1774   // second element will start at an 8 byte offset.  We can't increase the size
1775   // of the second element because it might make us access off the end of the
1776   // struct.
1777   if (HiStart != 8) {
1778     // There are only two sorts of types the ABI generation code can produce for
1779     // the low part of a pair that aren't 8 bytes in size: float or i8/i16/i32.
1780     // Promote these to a larger type.
1781     if (Lo->isFloatTy())
1782       Lo = llvm::Type::getDoubleTy(Lo->getContext());
1783     else {
1784       assert(Lo->isIntegerTy() && "Invalid/unknown lo type");
1785       Lo = llvm::Type::getInt64Ty(Lo->getContext());
1786     }
1787   }
1788 
1789   llvm::StructType *Result = llvm::StructType::get(Lo, Hi, NULL);
1790 
1791 
1792   // Verify that the second element is at an 8-byte offset.
1793   assert(TD.getStructLayout(Result)->getElementOffset(1) == 8 &&
1794          "Invalid x86-64 argument pair!");
1795   return Result;
1796 }
1797 
1798 ABIArgInfo X86_64ABIInfo::
1799 classifyReturnType(QualType RetTy) const {
1800   // AMD64-ABI 3.2.3p4: Rule 1. Classify the return type with the
1801   // classification algorithm.
1802   X86_64ABIInfo::Class Lo, Hi;
1803   classify(RetTy, 0, Lo, Hi);
1804 
1805   // Check some invariants.
1806   assert((Hi != Memory || Lo == Memory) && "Invalid memory classification.");
1807   assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp classification.");
1808 
1809   llvm::Type *ResType = 0;
1810   switch (Lo) {
1811   case NoClass:
1812     if (Hi == NoClass)
1813       return ABIArgInfo::getIgnore();
1814     // If the low part is just padding, it takes no register, leave ResType
1815     // null.
1816     assert((Hi == SSE || Hi == Integer || Hi == X87Up) &&
1817            "Unknown missing lo part");
1818     break;
1819 
1820   case SSEUp:
1821   case X87Up:
1822     llvm_unreachable("Invalid classification for lo word.");
1823 
1824     // AMD64-ABI 3.2.3p4: Rule 2. Types of class memory are returned via
1825     // hidden argument.
1826   case Memory:
1827     return getIndirectReturnResult(RetTy);
1828 
1829     // AMD64-ABI 3.2.3p4: Rule 3. If the class is INTEGER, the next
1830     // available register of the sequence %rax, %rdx is used.
1831   case Integer:
1832     ResType = GetINTEGERTypeAtOffset(CGT.ConvertType(RetTy), 0, RetTy, 0);
1833 
1834     // If we have a sign or zero extended integer, make sure to return Extend
1835     // so that the parameter gets the right LLVM IR attributes.
1836     if (Hi == NoClass && isa<llvm::IntegerType>(ResType)) {
1837       // Treat an enum type as its underlying type.
1838       if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
1839         RetTy = EnumTy->getDecl()->getIntegerType();
1840 
1841       if (RetTy->isIntegralOrEnumerationType() &&
1842           RetTy->isPromotableIntegerType())
1843         return ABIArgInfo::getExtend();
1844     }
1845     break;
1846 
1847     // AMD64-ABI 3.2.3p4: Rule 4. If the class is SSE, the next
1848     // available SSE register of the sequence %xmm0, %xmm1 is used.
1849   case SSE:
1850     ResType = GetSSETypeAtOffset(CGT.ConvertType(RetTy), 0, RetTy, 0);
1851     break;
1852 
1853     // AMD64-ABI 3.2.3p4: Rule 6. If the class is X87, the value is
1854     // returned on the X87 stack in %st0 as 80-bit x87 number.
1855   case X87:
1856     ResType = llvm::Type::getX86_FP80Ty(getVMContext());
1857     break;
1858 
1859     // AMD64-ABI 3.2.3p4: Rule 8. If the class is COMPLEX_X87, the real
1860     // part of the value is returned in %st0 and the imaginary part in
1861     // %st1.
1862   case ComplexX87:
1863     assert(Hi == ComplexX87 && "Unexpected ComplexX87 classification.");
1864     ResType = llvm::StructType::get(llvm::Type::getX86_FP80Ty(getVMContext()),
1865                                     llvm::Type::getX86_FP80Ty(getVMContext()),
1866                                     NULL);
1867     break;
1868   }
1869 
1870   llvm::Type *HighPart = 0;
1871   switch (Hi) {
1872     // Memory was handled previously and X87 should
1873     // never occur as a hi class.
1874   case Memory:
1875   case X87:
1876     llvm_unreachable("Invalid classification for hi word.");
1877 
1878   case ComplexX87: // Previously handled.
1879   case NoClass:
1880     break;
1881 
1882   case Integer:
1883     HighPart = GetINTEGERTypeAtOffset(CGT.ConvertType(RetTy), 8, RetTy, 8);
1884     if (Lo == NoClass)  // Return HighPart at offset 8 in memory.
1885       return ABIArgInfo::getDirect(HighPart, 8);
1886     break;
1887   case SSE:
1888     HighPart = GetSSETypeAtOffset(CGT.ConvertType(RetTy), 8, RetTy, 8);
1889     if (Lo == NoClass)  // Return HighPart at offset 8 in memory.
1890       return ABIArgInfo::getDirect(HighPart, 8);
1891     break;
1892 
1893     // AMD64-ABI 3.2.3p4: Rule 5. If the class is SSEUP, the eightbyte
1894     // is passed in the next available eightbyte chunk if the last used
1895     // vector register.
1896     //
1897     // SSEUP should always be preceded by SSE, just widen.
1898   case SSEUp:
1899     assert(Lo == SSE && "Unexpected SSEUp classification.");
1900     ResType = GetByteVectorType(RetTy);
1901     break;
1902 
1903     // AMD64-ABI 3.2.3p4: Rule 7. If the class is X87UP, the value is
1904     // returned together with the previous X87 value in %st0.
1905   case X87Up:
1906     // If X87Up is preceded by X87, we don't need to do
1907     // anything. However, in some cases with unions it may not be
1908     // preceded by X87. In such situations we follow gcc and pass the
1909     // extra bits in an SSE reg.
1910     if (Lo != X87) {
1911       HighPart = GetSSETypeAtOffset(CGT.ConvertType(RetTy), 8, RetTy, 8);
1912       if (Lo == NoClass)  // Return HighPart at offset 8 in memory.
1913         return ABIArgInfo::getDirect(HighPart, 8);
1914     }
1915     break;
1916   }
1917 
1918   // If a high part was specified, merge it together with the low part.  It is
1919   // known to pass in the high eightbyte of the result.  We do this by forming a
1920   // first class struct aggregate with the high and low part: {low, high}
1921   if (HighPart)
1922     ResType = GetX86_64ByValArgumentPair(ResType, HighPart, getTargetData());
1923 
1924   return ABIArgInfo::getDirect(ResType);
1925 }
1926 
1927 ABIArgInfo X86_64ABIInfo::classifyArgumentType(
1928   QualType Ty, unsigned freeIntRegs, unsigned &neededInt, unsigned &neededSSE)
1929   const
1930 {
1931   X86_64ABIInfo::Class Lo, Hi;
1932   classify(Ty, 0, Lo, Hi);
1933 
1934   // Check some invariants.
1935   // FIXME: Enforce these by construction.
1936   assert((Hi != Memory || Lo == Memory) && "Invalid memory classification.");
1937   assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp classification.");
1938 
1939   neededInt = 0;
1940   neededSSE = 0;
1941   llvm::Type *ResType = 0;
1942   switch (Lo) {
1943   case NoClass:
1944     if (Hi == NoClass)
1945       return ABIArgInfo::getIgnore();
1946     // If the low part is just padding, it takes no register, leave ResType
1947     // null.
1948     assert((Hi == SSE || Hi == Integer || Hi == X87Up) &&
1949            "Unknown missing lo part");
1950     break;
1951 
1952     // AMD64-ABI 3.2.3p3: Rule 1. If the class is MEMORY, pass the argument
1953     // on the stack.
1954   case Memory:
1955 
1956     // AMD64-ABI 3.2.3p3: Rule 5. If the class is X87, X87UP or
1957     // COMPLEX_X87, it is passed in memory.
1958   case X87:
1959   case ComplexX87:
1960     if (isRecordWithNonTrivialDestructorOrCopyConstructor(Ty))
1961       ++neededInt;
1962     return getIndirectResult(Ty, freeIntRegs);
1963 
1964   case SSEUp:
1965   case X87Up:
1966     llvm_unreachable("Invalid classification for lo word.");
1967 
1968     // AMD64-ABI 3.2.3p3: Rule 2. If the class is INTEGER, the next
1969     // available register of the sequence %rdi, %rsi, %rdx, %rcx, %r8
1970     // and %r9 is used.
1971   case Integer:
1972     ++neededInt;
1973 
1974     // Pick an 8-byte type based on the preferred type.
1975     ResType = GetINTEGERTypeAtOffset(CGT.ConvertType(Ty), 0, Ty, 0);
1976 
1977     // If we have a sign or zero extended integer, make sure to return Extend
1978     // so that the parameter gets the right LLVM IR attributes.
1979     if (Hi == NoClass && isa<llvm::IntegerType>(ResType)) {
1980       // Treat an enum type as its underlying type.
1981       if (const EnumType *EnumTy = Ty->getAs<EnumType>())
1982         Ty = EnumTy->getDecl()->getIntegerType();
1983 
1984       if (Ty->isIntegralOrEnumerationType() &&
1985           Ty->isPromotableIntegerType())
1986         return ABIArgInfo::getExtend();
1987     }
1988 
1989     break;
1990 
1991     // AMD64-ABI 3.2.3p3: Rule 3. If the class is SSE, the next
1992     // available SSE register is used, the registers are taken in the
1993     // order from %xmm0 to %xmm7.
1994   case SSE: {
1995     llvm::Type *IRType = CGT.ConvertType(Ty);
1996     ResType = GetSSETypeAtOffset(IRType, 0, Ty, 0);
1997     ++neededSSE;
1998     break;
1999   }
2000   }
2001 
2002   llvm::Type *HighPart = 0;
2003   switch (Hi) {
2004     // Memory was handled previously, ComplexX87 and X87 should
2005     // never occur as hi classes, and X87Up must be preceded by X87,
2006     // which is passed in memory.
2007   case Memory:
2008   case X87:
2009   case ComplexX87:
2010     llvm_unreachable("Invalid classification for hi word.");
2011 
2012   case NoClass: break;
2013 
2014   case Integer:
2015     ++neededInt;
2016     // Pick an 8-byte type based on the preferred type.
2017     HighPart = GetINTEGERTypeAtOffset(CGT.ConvertType(Ty), 8, Ty, 8);
2018 
2019     if (Lo == NoClass)  // Pass HighPart at offset 8 in memory.
2020       return ABIArgInfo::getDirect(HighPart, 8);
2021     break;
2022 
2023     // X87Up generally doesn't occur here (long double is passed in
2024     // memory), except in situations involving unions.
2025   case X87Up:
2026   case SSE:
2027     HighPart = GetSSETypeAtOffset(CGT.ConvertType(Ty), 8, Ty, 8);
2028 
2029     if (Lo == NoClass)  // Pass HighPart at offset 8 in memory.
2030       return ABIArgInfo::getDirect(HighPart, 8);
2031 
2032     ++neededSSE;
2033     break;
2034 
2035     // AMD64-ABI 3.2.3p3: Rule 4. If the class is SSEUP, the
2036     // eightbyte is passed in the upper half of the last used SSE
2037     // register.  This only happens when 128-bit vectors are passed.
2038   case SSEUp:
2039     assert(Lo == SSE && "Unexpected SSEUp classification");
2040     ResType = GetByteVectorType(Ty);
2041     break;
2042   }
2043 
2044   // If a high part was specified, merge it together with the low part.  It is
2045   // known to pass in the high eightbyte of the result.  We do this by forming a
2046   // first class struct aggregate with the high and low part: {low, high}
2047   if (HighPart)
2048     ResType = GetX86_64ByValArgumentPair(ResType, HighPart, getTargetData());
2049 
2050   return ABIArgInfo::getDirect(ResType);
2051 }
2052 
2053 void X86_64ABIInfo::computeInfo(CGFunctionInfo &FI) const {
2054 
2055   FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
2056 
2057   // Keep track of the number of assigned registers.
2058   unsigned freeIntRegs = 6, freeSSERegs = 8;
2059 
2060   // If the return value is indirect, then the hidden argument is consuming one
2061   // integer register.
2062   if (FI.getReturnInfo().isIndirect())
2063     --freeIntRegs;
2064 
2065   // AMD64-ABI 3.2.3p3: Once arguments are classified, the registers
2066   // get assigned (in left-to-right order) for passing as follows...
2067   for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
2068        it != ie; ++it) {
2069     unsigned neededInt, neededSSE;
2070     it->info = classifyArgumentType(it->type, freeIntRegs, neededInt,
2071                                     neededSSE);
2072 
2073     // AMD64-ABI 3.2.3p3: If there are no registers available for any
2074     // eightbyte of an argument, the whole argument is passed on the
2075     // stack. If registers have already been assigned for some
2076     // eightbytes of such an argument, the assignments get reverted.
2077     if (freeIntRegs >= neededInt && freeSSERegs >= neededSSE) {
2078       freeIntRegs -= neededInt;
2079       freeSSERegs -= neededSSE;
2080     } else {
2081       it->info = getIndirectResult(it->type, freeIntRegs);
2082     }
2083   }
2084 }
2085 
2086 static llvm::Value *EmitVAArgFromMemory(llvm::Value *VAListAddr,
2087                                         QualType Ty,
2088                                         CodeGenFunction &CGF) {
2089   llvm::Value *overflow_arg_area_p =
2090     CGF.Builder.CreateStructGEP(VAListAddr, 2, "overflow_arg_area_p");
2091   llvm::Value *overflow_arg_area =
2092     CGF.Builder.CreateLoad(overflow_arg_area_p, "overflow_arg_area");
2093 
2094   // AMD64-ABI 3.5.7p5: Step 7. Align l->overflow_arg_area upwards to a 16
2095   // byte boundary if alignment needed by type exceeds 8 byte boundary.
2096   // It isn't stated explicitly in the standard, but in practice we use
2097   // alignment greater than 16 where necessary.
2098   uint64_t Align = CGF.getContext().getTypeAlign(Ty) / 8;
2099   if (Align > 8) {
2100     // overflow_arg_area = (overflow_arg_area + align - 1) & -align;
2101     llvm::Value *Offset =
2102       llvm::ConstantInt::get(CGF.Int64Ty, Align - 1);
2103     overflow_arg_area = CGF.Builder.CreateGEP(overflow_arg_area, Offset);
2104     llvm::Value *AsInt = CGF.Builder.CreatePtrToInt(overflow_arg_area,
2105                                                     CGF.Int64Ty);
2106     llvm::Value *Mask = llvm::ConstantInt::get(CGF.Int64Ty, -(uint64_t)Align);
2107     overflow_arg_area =
2108       CGF.Builder.CreateIntToPtr(CGF.Builder.CreateAnd(AsInt, Mask),
2109                                  overflow_arg_area->getType(),
2110                                  "overflow_arg_area.align");
2111   }
2112 
2113   // AMD64-ABI 3.5.7p5: Step 8. Fetch type from l->overflow_arg_area.
2114   llvm::Type *LTy = CGF.ConvertTypeForMem(Ty);
2115   llvm::Value *Res =
2116     CGF.Builder.CreateBitCast(overflow_arg_area,
2117                               llvm::PointerType::getUnqual(LTy));
2118 
2119   // AMD64-ABI 3.5.7p5: Step 9. Set l->overflow_arg_area to:
2120   // l->overflow_arg_area + sizeof(type).
2121   // AMD64-ABI 3.5.7p5: Step 10. Align l->overflow_arg_area upwards to
2122   // an 8 byte boundary.
2123 
2124   uint64_t SizeInBytes = (CGF.getContext().getTypeSize(Ty) + 7) / 8;
2125   llvm::Value *Offset =
2126       llvm::ConstantInt::get(CGF.Int32Ty, (SizeInBytes + 7)  & ~7);
2127   overflow_arg_area = CGF.Builder.CreateGEP(overflow_arg_area, Offset,
2128                                             "overflow_arg_area.next");
2129   CGF.Builder.CreateStore(overflow_arg_area, overflow_arg_area_p);
2130 
2131   // AMD64-ABI 3.5.7p5: Step 11. Return the fetched type.
2132   return Res;
2133 }
2134 
2135 llvm::Value *X86_64ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
2136                                       CodeGenFunction &CGF) const {
2137   // Assume that va_list type is correct; should be pointer to LLVM type:
2138   // struct {
2139   //   i32 gp_offset;
2140   //   i32 fp_offset;
2141   //   i8* overflow_arg_area;
2142   //   i8* reg_save_area;
2143   // };
2144   unsigned neededInt, neededSSE;
2145 
2146   Ty = CGF.getContext().getCanonicalType(Ty);
2147   ABIArgInfo AI = classifyArgumentType(Ty, 0, neededInt, neededSSE);
2148 
2149   // AMD64-ABI 3.5.7p5: Step 1. Determine whether type may be passed
2150   // in the registers. If not go to step 7.
2151   if (!neededInt && !neededSSE)
2152     return EmitVAArgFromMemory(VAListAddr, Ty, CGF);
2153 
2154   // AMD64-ABI 3.5.7p5: Step 2. Compute num_gp to hold the number of
2155   // general purpose registers needed to pass type and num_fp to hold
2156   // the number of floating point registers needed.
2157 
2158   // AMD64-ABI 3.5.7p5: Step 3. Verify whether arguments fit into
2159   // registers. In the case: l->gp_offset > 48 - num_gp * 8 or
2160   // l->fp_offset > 304 - num_fp * 16 go to step 7.
2161   //
2162   // NOTE: 304 is a typo, there are (6 * 8 + 8 * 16) = 176 bytes of
2163   // register save space).
2164 
2165   llvm::Value *InRegs = 0;
2166   llvm::Value *gp_offset_p = 0, *gp_offset = 0;
2167   llvm::Value *fp_offset_p = 0, *fp_offset = 0;
2168   if (neededInt) {
2169     gp_offset_p = CGF.Builder.CreateStructGEP(VAListAddr, 0, "gp_offset_p");
2170     gp_offset = CGF.Builder.CreateLoad(gp_offset_p, "gp_offset");
2171     InRegs = llvm::ConstantInt::get(CGF.Int32Ty, 48 - neededInt * 8);
2172     InRegs = CGF.Builder.CreateICmpULE(gp_offset, InRegs, "fits_in_gp");
2173   }
2174 
2175   if (neededSSE) {
2176     fp_offset_p = CGF.Builder.CreateStructGEP(VAListAddr, 1, "fp_offset_p");
2177     fp_offset = CGF.Builder.CreateLoad(fp_offset_p, "fp_offset");
2178     llvm::Value *FitsInFP =
2179       llvm::ConstantInt::get(CGF.Int32Ty, 176 - neededSSE * 16);
2180     FitsInFP = CGF.Builder.CreateICmpULE(fp_offset, FitsInFP, "fits_in_fp");
2181     InRegs = InRegs ? CGF.Builder.CreateAnd(InRegs, FitsInFP) : FitsInFP;
2182   }
2183 
2184   llvm::BasicBlock *InRegBlock = CGF.createBasicBlock("vaarg.in_reg");
2185   llvm::BasicBlock *InMemBlock = CGF.createBasicBlock("vaarg.in_mem");
2186   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("vaarg.end");
2187   CGF.Builder.CreateCondBr(InRegs, InRegBlock, InMemBlock);
2188 
2189   // Emit code to load the value if it was passed in registers.
2190 
2191   CGF.EmitBlock(InRegBlock);
2192 
2193   // AMD64-ABI 3.5.7p5: Step 4. Fetch type from l->reg_save_area with
2194   // an offset of l->gp_offset and/or l->fp_offset. This may require
2195   // copying to a temporary location in case the parameter is passed
2196   // in different register classes or requires an alignment greater
2197   // than 8 for general purpose registers and 16 for XMM registers.
2198   //
2199   // FIXME: This really results in shameful code when we end up needing to
2200   // collect arguments from different places; often what should result in a
2201   // simple assembling of a structure from scattered addresses has many more
2202   // loads than necessary. Can we clean this up?
2203   llvm::Type *LTy = CGF.ConvertTypeForMem(Ty);
2204   llvm::Value *RegAddr =
2205     CGF.Builder.CreateLoad(CGF.Builder.CreateStructGEP(VAListAddr, 3),
2206                            "reg_save_area");
2207   if (neededInt && neededSSE) {
2208     // FIXME: Cleanup.
2209     assert(AI.isDirect() && "Unexpected ABI info for mixed regs");
2210     llvm::StructType *ST = cast<llvm::StructType>(AI.getCoerceToType());
2211     llvm::Value *Tmp = CGF.CreateTempAlloca(ST);
2212     assert(ST->getNumElements() == 2 && "Unexpected ABI info for mixed regs");
2213     llvm::Type *TyLo = ST->getElementType(0);
2214     llvm::Type *TyHi = ST->getElementType(1);
2215     assert((TyLo->isFPOrFPVectorTy() ^ TyHi->isFPOrFPVectorTy()) &&
2216            "Unexpected ABI info for mixed regs");
2217     llvm::Type *PTyLo = llvm::PointerType::getUnqual(TyLo);
2218     llvm::Type *PTyHi = llvm::PointerType::getUnqual(TyHi);
2219     llvm::Value *GPAddr = CGF.Builder.CreateGEP(RegAddr, gp_offset);
2220     llvm::Value *FPAddr = CGF.Builder.CreateGEP(RegAddr, fp_offset);
2221     llvm::Value *RegLoAddr = TyLo->isFloatingPointTy() ? FPAddr : GPAddr;
2222     llvm::Value *RegHiAddr = TyLo->isFloatingPointTy() ? GPAddr : FPAddr;
2223     llvm::Value *V =
2224       CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegLoAddr, PTyLo));
2225     CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 0));
2226     V = CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegHiAddr, PTyHi));
2227     CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 1));
2228 
2229     RegAddr = CGF.Builder.CreateBitCast(Tmp,
2230                                         llvm::PointerType::getUnqual(LTy));
2231   } else if (neededInt) {
2232     RegAddr = CGF.Builder.CreateGEP(RegAddr, gp_offset);
2233     RegAddr = CGF.Builder.CreateBitCast(RegAddr,
2234                                         llvm::PointerType::getUnqual(LTy));
2235   } else if (neededSSE == 1) {
2236     RegAddr = CGF.Builder.CreateGEP(RegAddr, fp_offset);
2237     RegAddr = CGF.Builder.CreateBitCast(RegAddr,
2238                                         llvm::PointerType::getUnqual(LTy));
2239   } else {
2240     assert(neededSSE == 2 && "Invalid number of needed registers!");
2241     // SSE registers are spaced 16 bytes apart in the register save
2242     // area, we need to collect the two eightbytes together.
2243     llvm::Value *RegAddrLo = CGF.Builder.CreateGEP(RegAddr, fp_offset);
2244     llvm::Value *RegAddrHi = CGF.Builder.CreateConstGEP1_32(RegAddrLo, 16);
2245     llvm::Type *DoubleTy = CGF.DoubleTy;
2246     llvm::Type *DblPtrTy =
2247       llvm::PointerType::getUnqual(DoubleTy);
2248     llvm::StructType *ST = llvm::StructType::get(DoubleTy,
2249                                                        DoubleTy, NULL);
2250     llvm::Value *V, *Tmp = CGF.CreateTempAlloca(ST);
2251     V = CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegAddrLo,
2252                                                          DblPtrTy));
2253     CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 0));
2254     V = CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegAddrHi,
2255                                                          DblPtrTy));
2256     CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 1));
2257     RegAddr = CGF.Builder.CreateBitCast(Tmp,
2258                                         llvm::PointerType::getUnqual(LTy));
2259   }
2260 
2261   // AMD64-ABI 3.5.7p5: Step 5. Set:
2262   // l->gp_offset = l->gp_offset + num_gp * 8
2263   // l->fp_offset = l->fp_offset + num_fp * 16.
2264   if (neededInt) {
2265     llvm::Value *Offset = llvm::ConstantInt::get(CGF.Int32Ty, neededInt * 8);
2266     CGF.Builder.CreateStore(CGF.Builder.CreateAdd(gp_offset, Offset),
2267                             gp_offset_p);
2268   }
2269   if (neededSSE) {
2270     llvm::Value *Offset = llvm::ConstantInt::get(CGF.Int32Ty, neededSSE * 16);
2271     CGF.Builder.CreateStore(CGF.Builder.CreateAdd(fp_offset, Offset),
2272                             fp_offset_p);
2273   }
2274   CGF.EmitBranch(ContBlock);
2275 
2276   // Emit code to load the value if it was passed in memory.
2277 
2278   CGF.EmitBlock(InMemBlock);
2279   llvm::Value *MemAddr = EmitVAArgFromMemory(VAListAddr, Ty, CGF);
2280 
2281   // Return the appropriate result.
2282 
2283   CGF.EmitBlock(ContBlock);
2284   llvm::PHINode *ResAddr = CGF.Builder.CreatePHI(RegAddr->getType(), 2,
2285                                                  "vaarg.addr");
2286   ResAddr->addIncoming(RegAddr, InRegBlock);
2287   ResAddr->addIncoming(MemAddr, InMemBlock);
2288   return ResAddr;
2289 }
2290 
2291 ABIArgInfo WinX86_64ABIInfo::classify(QualType Ty) const {
2292 
2293   if (Ty->isVoidType())
2294     return ABIArgInfo::getIgnore();
2295 
2296   if (const EnumType *EnumTy = Ty->getAs<EnumType>())
2297     Ty = EnumTy->getDecl()->getIntegerType();
2298 
2299   uint64_t Size = getContext().getTypeSize(Ty);
2300 
2301   if (const RecordType *RT = Ty->getAs<RecordType>()) {
2302     if (hasNonTrivialDestructorOrCopyConstructor(RT) ||
2303         RT->getDecl()->hasFlexibleArrayMember())
2304       return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
2305 
2306     // FIXME: mingw-w64-gcc emits 128-bit struct as i128
2307     if (Size == 128 &&
2308         getContext().getTargetInfo().getTriple().getOS()
2309           == llvm::Triple::MinGW32)
2310       return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),
2311                                                           Size));
2312 
2313     // MS x64 ABI requirement: "Any argument that doesn't fit in 8 bytes, or is
2314     // not 1, 2, 4, or 8 bytes, must be passed by reference."
2315     if (Size <= 64 &&
2316         (Size & (Size - 1)) == 0)
2317       return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),
2318                                                           Size));
2319 
2320     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
2321   }
2322 
2323   if (Ty->isPromotableIntegerType())
2324     return ABIArgInfo::getExtend();
2325 
2326   return ABIArgInfo::getDirect();
2327 }
2328 
2329 void WinX86_64ABIInfo::computeInfo(CGFunctionInfo &FI) const {
2330 
2331   QualType RetTy = FI.getReturnType();
2332   FI.getReturnInfo() = classify(RetTy);
2333 
2334   for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
2335        it != ie; ++it)
2336     it->info = classify(it->type);
2337 }
2338 
2339 llvm::Value *WinX86_64ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
2340                                       CodeGenFunction &CGF) const {
2341   llvm::Type *BPP = CGF.Int8PtrPtrTy;
2342 
2343   CGBuilderTy &Builder = CGF.Builder;
2344   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP,
2345                                                        "ap");
2346   llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
2347   llvm::Type *PTy =
2348     llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
2349   llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy);
2350 
2351   uint64_t Offset =
2352     llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, 8);
2353   llvm::Value *NextAddr =
2354     Builder.CreateGEP(Addr, llvm::ConstantInt::get(CGF.Int32Ty, Offset),
2355                       "ap.next");
2356   Builder.CreateStore(NextAddr, VAListAddrAsBPP);
2357 
2358   return AddrTyped;
2359 }
2360 
2361 // PowerPC-32
2362 
2363 namespace {
2364 class PPC32TargetCodeGenInfo : public DefaultTargetCodeGenInfo {
2365 public:
2366   PPC32TargetCodeGenInfo(CodeGenTypes &CGT) : DefaultTargetCodeGenInfo(CGT) {}
2367 
2368   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const {
2369     // This is recovered from gcc output.
2370     return 1; // r1 is the dedicated stack pointer
2371   }
2372 
2373   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
2374                                llvm::Value *Address) const;
2375 };
2376 
2377 }
2378 
2379 bool
2380 PPC32TargetCodeGenInfo::initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
2381                                                 llvm::Value *Address) const {
2382   // This is calculated from the LLVM and GCC tables and verified
2383   // against gcc output.  AFAIK all ABIs use the same encoding.
2384 
2385   CodeGen::CGBuilderTy &Builder = CGF.Builder;
2386 
2387   llvm::IntegerType *i8 = CGF.Int8Ty;
2388   llvm::Value *Four8 = llvm::ConstantInt::get(i8, 4);
2389   llvm::Value *Eight8 = llvm::ConstantInt::get(i8, 8);
2390   llvm::Value *Sixteen8 = llvm::ConstantInt::get(i8, 16);
2391 
2392   // 0-31: r0-31, the 4-byte general-purpose registers
2393   AssignToArrayRange(Builder, Address, Four8, 0, 31);
2394 
2395   // 32-63: fp0-31, the 8-byte floating-point registers
2396   AssignToArrayRange(Builder, Address, Eight8, 32, 63);
2397 
2398   // 64-76 are various 4-byte special-purpose registers:
2399   // 64: mq
2400   // 65: lr
2401   // 66: ctr
2402   // 67: ap
2403   // 68-75 cr0-7
2404   // 76: xer
2405   AssignToArrayRange(Builder, Address, Four8, 64, 76);
2406 
2407   // 77-108: v0-31, the 16-byte vector registers
2408   AssignToArrayRange(Builder, Address, Sixteen8, 77, 108);
2409 
2410   // 109: vrsave
2411   // 110: vscr
2412   // 111: spe_acc
2413   // 112: spefscr
2414   // 113: sfp
2415   AssignToArrayRange(Builder, Address, Four8, 109, 113);
2416 
2417   return false;
2418 }
2419 
2420 // PowerPC-64
2421 
2422 namespace {
2423 class PPC64TargetCodeGenInfo : public DefaultTargetCodeGenInfo {
2424 public:
2425   PPC64TargetCodeGenInfo(CodeGenTypes &CGT) : DefaultTargetCodeGenInfo(CGT) {}
2426 
2427   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const {
2428     // This is recovered from gcc output.
2429     return 1; // r1 is the dedicated stack pointer
2430   }
2431 
2432   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
2433                                llvm::Value *Address) const;
2434 };
2435 
2436 }
2437 
2438 bool
2439 PPC64TargetCodeGenInfo::initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
2440                                                 llvm::Value *Address) const {
2441   // This is calculated from the LLVM and GCC tables and verified
2442   // against gcc output.  AFAIK all ABIs use the same encoding.
2443 
2444   CodeGen::CGBuilderTy &Builder = CGF.Builder;
2445 
2446   llvm::IntegerType *i8 = CGF.Int8Ty;
2447   llvm::Value *Four8 = llvm::ConstantInt::get(i8, 4);
2448   llvm::Value *Eight8 = llvm::ConstantInt::get(i8, 8);
2449   llvm::Value *Sixteen8 = llvm::ConstantInt::get(i8, 16);
2450 
2451   // 0-31: r0-31, the 8-byte general-purpose registers
2452   AssignToArrayRange(Builder, Address, Eight8, 0, 31);
2453 
2454   // 32-63: fp0-31, the 8-byte floating-point registers
2455   AssignToArrayRange(Builder, Address, Eight8, 32, 63);
2456 
2457   // 64-76 are various 4-byte special-purpose registers:
2458   // 64: mq
2459   // 65: lr
2460   // 66: ctr
2461   // 67: ap
2462   // 68-75 cr0-7
2463   // 76: xer
2464   AssignToArrayRange(Builder, Address, Four8, 64, 76);
2465 
2466   // 77-108: v0-31, the 16-byte vector registers
2467   AssignToArrayRange(Builder, Address, Sixteen8, 77, 108);
2468 
2469   // 109: vrsave
2470   // 110: vscr
2471   // 111: spe_acc
2472   // 112: spefscr
2473   // 113: sfp
2474   AssignToArrayRange(Builder, Address, Four8, 109, 113);
2475 
2476   return false;
2477 }
2478 
2479 //===----------------------------------------------------------------------===//
2480 // ARM ABI Implementation
2481 //===----------------------------------------------------------------------===//
2482 
2483 namespace {
2484 
2485 class ARMABIInfo : public ABIInfo {
2486 public:
2487   enum ABIKind {
2488     APCS = 0,
2489     AAPCS = 1,
2490     AAPCS_VFP
2491   };
2492 
2493 private:
2494   ABIKind Kind;
2495 
2496 public:
2497   ARMABIInfo(CodeGenTypes &CGT, ABIKind _Kind) : ABIInfo(CGT), Kind(_Kind) {}
2498 
2499   bool isEABI() const {
2500     StringRef Env =
2501       getContext().getTargetInfo().getTriple().getEnvironmentName();
2502     return (Env == "gnueabi" || Env == "eabi" || Env == "androideabi");
2503   }
2504 
2505 private:
2506   ABIKind getABIKind() const { return Kind; }
2507 
2508   ABIArgInfo classifyReturnType(QualType RetTy) const;
2509   ABIArgInfo classifyArgumentType(QualType RetTy) const;
2510 
2511   virtual void computeInfo(CGFunctionInfo &FI) const;
2512 
2513   virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
2514                                  CodeGenFunction &CGF) const;
2515 };
2516 
2517 class ARMTargetCodeGenInfo : public TargetCodeGenInfo {
2518 public:
2519   ARMTargetCodeGenInfo(CodeGenTypes &CGT, ARMABIInfo::ABIKind K)
2520     :TargetCodeGenInfo(new ARMABIInfo(CGT, K)) {}
2521 
2522   const ARMABIInfo &getABIInfo() const {
2523     return static_cast<const ARMABIInfo&>(TargetCodeGenInfo::getABIInfo());
2524   }
2525 
2526   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const {
2527     return 13;
2528   }
2529 
2530   StringRef getARCRetainAutoreleasedReturnValueMarker() const {
2531     return "mov\tr7, r7\t\t@ marker for objc_retainAutoreleaseReturnValue";
2532   }
2533 
2534   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
2535                                llvm::Value *Address) const {
2536     llvm::Value *Four8 = llvm::ConstantInt::get(CGF.Int8Ty, 4);
2537 
2538     // 0-15 are the 16 integer registers.
2539     AssignToArrayRange(CGF.Builder, Address, Four8, 0, 15);
2540     return false;
2541   }
2542 
2543   unsigned getSizeOfUnwindException() const {
2544     if (getABIInfo().isEABI()) return 88;
2545     return TargetCodeGenInfo::getSizeOfUnwindException();
2546   }
2547 };
2548 
2549 }
2550 
2551 void ARMABIInfo::computeInfo(CGFunctionInfo &FI) const {
2552   FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
2553   for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
2554        it != ie; ++it)
2555     it->info = classifyArgumentType(it->type);
2556 
2557   // Always honor user-specified calling convention.
2558   if (FI.getCallingConvention() != llvm::CallingConv::C)
2559     return;
2560 
2561   // Calling convention as default by an ABI.
2562   llvm::CallingConv::ID DefaultCC;
2563   if (isEABI())
2564     DefaultCC = llvm::CallingConv::ARM_AAPCS;
2565   else
2566     DefaultCC = llvm::CallingConv::ARM_APCS;
2567 
2568   // If user did not ask for specific calling convention explicitly (e.g. via
2569   // pcs attribute), set effective calling convention if it's different than ABI
2570   // default.
2571   switch (getABIKind()) {
2572   case APCS:
2573     if (DefaultCC != llvm::CallingConv::ARM_APCS)
2574       FI.setEffectiveCallingConvention(llvm::CallingConv::ARM_APCS);
2575     break;
2576   case AAPCS:
2577     if (DefaultCC != llvm::CallingConv::ARM_AAPCS)
2578       FI.setEffectiveCallingConvention(llvm::CallingConv::ARM_AAPCS);
2579     break;
2580   case AAPCS_VFP:
2581     if (DefaultCC != llvm::CallingConv::ARM_AAPCS_VFP)
2582       FI.setEffectiveCallingConvention(llvm::CallingConv::ARM_AAPCS_VFP);
2583     break;
2584   }
2585 }
2586 
2587 /// isHomogeneousAggregate - Return true if a type is an AAPCS-VFP homogeneous
2588 /// aggregate.  If HAMembers is non-null, the number of base elements
2589 /// contained in the type is returned through it; this is used for the
2590 /// recursive calls that check aggregate component types.
2591 static bool isHomogeneousAggregate(QualType Ty, const Type *&Base,
2592                                    ASTContext &Context,
2593                                    uint64_t *HAMembers = 0) {
2594   uint64_t Members = 0;
2595   if (const ConstantArrayType *AT = Context.getAsConstantArrayType(Ty)) {
2596     if (!isHomogeneousAggregate(AT->getElementType(), Base, Context, &Members))
2597       return false;
2598     Members *= AT->getSize().getZExtValue();
2599   } else if (const RecordType *RT = Ty->getAs<RecordType>()) {
2600     const RecordDecl *RD = RT->getDecl();
2601     if (RD->hasFlexibleArrayMember())
2602       return false;
2603 
2604     Members = 0;
2605     for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
2606          i != e; ++i) {
2607       const FieldDecl *FD = *i;
2608       uint64_t FldMembers;
2609       if (!isHomogeneousAggregate(FD->getType(), Base, Context, &FldMembers))
2610         return false;
2611 
2612       Members = (RD->isUnion() ?
2613                  std::max(Members, FldMembers) : Members + FldMembers);
2614     }
2615   } else {
2616     Members = 1;
2617     if (const ComplexType *CT = Ty->getAs<ComplexType>()) {
2618       Members = 2;
2619       Ty = CT->getElementType();
2620     }
2621 
2622     // Homogeneous aggregates for AAPCS-VFP must have base types of float,
2623     // double, or 64-bit or 128-bit vectors.
2624     if (const BuiltinType *BT = Ty->getAs<BuiltinType>()) {
2625       if (BT->getKind() != BuiltinType::Float &&
2626           BT->getKind() != BuiltinType::Double)
2627         return false;
2628     } else if (const VectorType *VT = Ty->getAs<VectorType>()) {
2629       unsigned VecSize = Context.getTypeSize(VT);
2630       if (VecSize != 64 && VecSize != 128)
2631         return false;
2632     } else {
2633       return false;
2634     }
2635 
2636     // The base type must be the same for all members.  Vector types of the
2637     // same total size are treated as being equivalent here.
2638     const Type *TyPtr = Ty.getTypePtr();
2639     if (!Base)
2640       Base = TyPtr;
2641     if (Base != TyPtr &&
2642         (!Base->isVectorType() || !TyPtr->isVectorType() ||
2643          Context.getTypeSize(Base) != Context.getTypeSize(TyPtr)))
2644       return false;
2645   }
2646 
2647   // Homogeneous Aggregates can have at most 4 members of the base type.
2648   if (HAMembers)
2649     *HAMembers = Members;
2650 
2651   return (Members > 0 && Members <= 4);
2652 }
2653 
2654 ABIArgInfo ARMABIInfo::classifyArgumentType(QualType Ty) const {
2655   if (!isAggregateTypeForABI(Ty)) {
2656     // Treat an enum type as its underlying type.
2657     if (const EnumType *EnumTy = Ty->getAs<EnumType>())
2658       Ty = EnumTy->getDecl()->getIntegerType();
2659 
2660     return (Ty->isPromotableIntegerType() ?
2661             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
2662   }
2663 
2664   // Ignore empty records.
2665   if (isEmptyRecord(getContext(), Ty, true))
2666     return ABIArgInfo::getIgnore();
2667 
2668   // Structures with either a non-trivial destructor or a non-trivial
2669   // copy constructor are always indirect.
2670   if (isRecordWithNonTrivialDestructorOrCopyConstructor(Ty))
2671     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
2672 
2673   if (getABIKind() == ARMABIInfo::AAPCS_VFP) {
2674     // Homogeneous Aggregates need to be expanded.
2675     const Type *Base = 0;
2676     if (isHomogeneousAggregate(Ty, Base, getContext())) {
2677       assert(Base && "Base class should be set for homogeneous aggregate");
2678       return ABIArgInfo::getExpand();
2679     }
2680   }
2681 
2682   // Otherwise, pass by coercing to a structure of the appropriate size.
2683   //
2684   // FIXME: This doesn't handle alignment > 64 bits.
2685   llvm::Type* ElemTy;
2686   unsigned SizeRegs;
2687   if (getContext().getTypeSizeInChars(Ty) <= CharUnits::fromQuantity(64)) {
2688     ElemTy = llvm::Type::getInt32Ty(getVMContext());
2689     SizeRegs = (getContext().getTypeSize(Ty) + 31) / 32;
2690   } else if (getABIKind() == ARMABIInfo::APCS) {
2691     // Initial ARM ByVal support is APCS-only.
2692     return ABIArgInfo::getIndirect(0, /*ByVal=*/true);
2693   } else {
2694     // FIXME: This is kind of nasty... but there isn't much choice
2695     // because most of the ARM calling conventions don't yet support
2696     // byval.
2697     ElemTy = llvm::Type::getInt64Ty(getVMContext());
2698     SizeRegs = (getContext().getTypeSize(Ty) + 63) / 64;
2699   }
2700 
2701   llvm::Type *STy =
2702     llvm::StructType::get(llvm::ArrayType::get(ElemTy, SizeRegs), NULL);
2703   return ABIArgInfo::getDirect(STy);
2704 }
2705 
2706 static bool isIntegerLikeType(QualType Ty, ASTContext &Context,
2707                               llvm::LLVMContext &VMContext) {
2708   // APCS, C Language Calling Conventions, Non-Simple Return Values: A structure
2709   // is called integer-like if its size is less than or equal to one word, and
2710   // the offset of each of its addressable sub-fields is zero.
2711 
2712   uint64_t Size = Context.getTypeSize(Ty);
2713 
2714   // Check that the type fits in a word.
2715   if (Size > 32)
2716     return false;
2717 
2718   // FIXME: Handle vector types!
2719   if (Ty->isVectorType())
2720     return false;
2721 
2722   // Float types are never treated as "integer like".
2723   if (Ty->isRealFloatingType())
2724     return false;
2725 
2726   // If this is a builtin or pointer type then it is ok.
2727   if (Ty->getAs<BuiltinType>() || Ty->isPointerType())
2728     return true;
2729 
2730   // Small complex integer types are "integer like".
2731   if (const ComplexType *CT = Ty->getAs<ComplexType>())
2732     return isIntegerLikeType(CT->getElementType(), Context, VMContext);
2733 
2734   // Single element and zero sized arrays should be allowed, by the definition
2735   // above, but they are not.
2736 
2737   // Otherwise, it must be a record type.
2738   const RecordType *RT = Ty->getAs<RecordType>();
2739   if (!RT) return false;
2740 
2741   // Ignore records with flexible arrays.
2742   const RecordDecl *RD = RT->getDecl();
2743   if (RD->hasFlexibleArrayMember())
2744     return false;
2745 
2746   // Check that all sub-fields are at offset 0, and are themselves "integer
2747   // like".
2748   const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
2749 
2750   bool HadField = false;
2751   unsigned idx = 0;
2752   for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
2753        i != e; ++i, ++idx) {
2754     const FieldDecl *FD = *i;
2755 
2756     // Bit-fields are not addressable, we only need to verify they are "integer
2757     // like". We still have to disallow a subsequent non-bitfield, for example:
2758     //   struct { int : 0; int x }
2759     // is non-integer like according to gcc.
2760     if (FD->isBitField()) {
2761       if (!RD->isUnion())
2762         HadField = true;
2763 
2764       if (!isIntegerLikeType(FD->getType(), Context, VMContext))
2765         return false;
2766 
2767       continue;
2768     }
2769 
2770     // Check if this field is at offset 0.
2771     if (Layout.getFieldOffset(idx) != 0)
2772       return false;
2773 
2774     if (!isIntegerLikeType(FD->getType(), Context, VMContext))
2775       return false;
2776 
2777     // Only allow at most one field in a structure. This doesn't match the
2778     // wording above, but follows gcc in situations with a field following an
2779     // empty structure.
2780     if (!RD->isUnion()) {
2781       if (HadField)
2782         return false;
2783 
2784       HadField = true;
2785     }
2786   }
2787 
2788   return true;
2789 }
2790 
2791 ABIArgInfo ARMABIInfo::classifyReturnType(QualType RetTy) const {
2792   if (RetTy->isVoidType())
2793     return ABIArgInfo::getIgnore();
2794 
2795   // Large vector types should be returned via memory.
2796   if (RetTy->isVectorType() && getContext().getTypeSize(RetTy) > 128)
2797     return ABIArgInfo::getIndirect(0);
2798 
2799   if (!isAggregateTypeForABI(RetTy)) {
2800     // Treat an enum type as its underlying type.
2801     if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
2802       RetTy = EnumTy->getDecl()->getIntegerType();
2803 
2804     return (RetTy->isPromotableIntegerType() ?
2805             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
2806   }
2807 
2808   // Structures with either a non-trivial destructor or a non-trivial
2809   // copy constructor are always indirect.
2810   if (isRecordWithNonTrivialDestructorOrCopyConstructor(RetTy))
2811     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
2812 
2813   // Are we following APCS?
2814   if (getABIKind() == APCS) {
2815     if (isEmptyRecord(getContext(), RetTy, false))
2816       return ABIArgInfo::getIgnore();
2817 
2818     // Complex types are all returned as packed integers.
2819     //
2820     // FIXME: Consider using 2 x vector types if the back end handles them
2821     // correctly.
2822     if (RetTy->isAnyComplexType())
2823       return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),
2824                                               getContext().getTypeSize(RetTy)));
2825 
2826     // Integer like structures are returned in r0.
2827     if (isIntegerLikeType(RetTy, getContext(), getVMContext())) {
2828       // Return in the smallest viable integer type.
2829       uint64_t Size = getContext().getTypeSize(RetTy);
2830       if (Size <= 8)
2831         return ABIArgInfo::getDirect(llvm::Type::getInt8Ty(getVMContext()));
2832       if (Size <= 16)
2833         return ABIArgInfo::getDirect(llvm::Type::getInt16Ty(getVMContext()));
2834       return ABIArgInfo::getDirect(llvm::Type::getInt32Ty(getVMContext()));
2835     }
2836 
2837     // Otherwise return in memory.
2838     return ABIArgInfo::getIndirect(0);
2839   }
2840 
2841   // Otherwise this is an AAPCS variant.
2842 
2843   if (isEmptyRecord(getContext(), RetTy, true))
2844     return ABIArgInfo::getIgnore();
2845 
2846   // Check for homogeneous aggregates with AAPCS-VFP.
2847   if (getABIKind() == AAPCS_VFP) {
2848     const Type *Base = 0;
2849     if (isHomogeneousAggregate(RetTy, Base, getContext())) {
2850       assert(Base && "Base class should be set for homogeneous aggregate");
2851       // Homogeneous Aggregates are returned directly.
2852       return ABIArgInfo::getDirect();
2853     }
2854   }
2855 
2856   // Aggregates <= 4 bytes are returned in r0; other aggregates
2857   // are returned indirectly.
2858   uint64_t Size = getContext().getTypeSize(RetTy);
2859   if (Size <= 32) {
2860     // Return in the smallest viable integer type.
2861     if (Size <= 8)
2862       return ABIArgInfo::getDirect(llvm::Type::getInt8Ty(getVMContext()));
2863     if (Size <= 16)
2864       return ABIArgInfo::getDirect(llvm::Type::getInt16Ty(getVMContext()));
2865     return ABIArgInfo::getDirect(llvm::Type::getInt32Ty(getVMContext()));
2866   }
2867 
2868   return ABIArgInfo::getIndirect(0);
2869 }
2870 
2871 llvm::Value *ARMABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
2872                                    CodeGenFunction &CGF) const {
2873   llvm::Type *BP = CGF.Int8PtrTy;
2874   llvm::Type *BPP = CGF.Int8PtrPtrTy;
2875 
2876   CGBuilderTy &Builder = CGF.Builder;
2877   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP, "ap");
2878   llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
2879   // Handle address alignment for type alignment > 32 bits
2880   uint64_t TyAlign = CGF.getContext().getTypeAlign(Ty) / 8;
2881   if (TyAlign > 4) {
2882     assert((TyAlign & (TyAlign - 1)) == 0 &&
2883            "Alignment is not power of 2!");
2884     llvm::Value *AddrAsInt = Builder.CreatePtrToInt(Addr, CGF.Int32Ty);
2885     AddrAsInt = Builder.CreateAdd(AddrAsInt, Builder.getInt32(TyAlign - 1));
2886     AddrAsInt = Builder.CreateAnd(AddrAsInt, Builder.getInt32(~(TyAlign - 1)));
2887     Addr = Builder.CreateIntToPtr(AddrAsInt, BP);
2888   }
2889   llvm::Type *PTy =
2890     llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
2891   llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy);
2892 
2893   uint64_t Offset =
2894     llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, 4);
2895   llvm::Value *NextAddr =
2896     Builder.CreateGEP(Addr, llvm::ConstantInt::get(CGF.Int32Ty, Offset),
2897                       "ap.next");
2898   Builder.CreateStore(NextAddr, VAListAddrAsBPP);
2899 
2900   return AddrTyped;
2901 }
2902 
2903 //===----------------------------------------------------------------------===//
2904 // NVPTX ABI Implementation
2905 //===----------------------------------------------------------------------===//
2906 
2907 namespace {
2908 
2909 class NVPTXABIInfo : public ABIInfo {
2910 public:
2911   NVPTXABIInfo(CodeGenTypes &CGT) : ABIInfo(CGT) {}
2912 
2913   ABIArgInfo classifyReturnType(QualType RetTy) const;
2914   ABIArgInfo classifyArgumentType(QualType Ty) const;
2915 
2916   virtual void computeInfo(CGFunctionInfo &FI) const;
2917   virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
2918                                  CodeGenFunction &CFG) const;
2919 };
2920 
2921 class NVPTXTargetCodeGenInfo : public TargetCodeGenInfo {
2922 public:
2923   NVPTXTargetCodeGenInfo(CodeGenTypes &CGT)
2924     : TargetCodeGenInfo(new NVPTXABIInfo(CGT)) {}
2925 
2926   virtual void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
2927                                    CodeGen::CodeGenModule &M) const;
2928 };
2929 
2930 ABIArgInfo NVPTXABIInfo::classifyReturnType(QualType RetTy) const {
2931   if (RetTy->isVoidType())
2932     return ABIArgInfo::getIgnore();
2933   if (isAggregateTypeForABI(RetTy))
2934     return ABIArgInfo::getIndirect(0);
2935   return ABIArgInfo::getDirect();
2936 }
2937 
2938 ABIArgInfo NVPTXABIInfo::classifyArgumentType(QualType Ty) const {
2939   if (isAggregateTypeForABI(Ty))
2940     return ABIArgInfo::getIndirect(0);
2941 
2942   return ABIArgInfo::getDirect();
2943 }
2944 
2945 void NVPTXABIInfo::computeInfo(CGFunctionInfo &FI) const {
2946   FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
2947   for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
2948        it != ie; ++it)
2949     it->info = classifyArgumentType(it->type);
2950 
2951   // Always honor user-specified calling convention.
2952   if (FI.getCallingConvention() != llvm::CallingConv::C)
2953     return;
2954 
2955   // Calling convention as default by an ABI.
2956   // We're still using the PTX_Kernel/PTX_Device calling conventions here,
2957   // but we should switch to NVVM metadata later on.
2958   llvm::CallingConv::ID DefaultCC;
2959   const LangOptions &LangOpts = getContext().getLangOpts();
2960   if (LangOpts.OpenCL || LangOpts.CUDA) {
2961     // If we are in OpenCL or CUDA mode, then default to device functions
2962     DefaultCC = llvm::CallingConv::PTX_Device;
2963   } else {
2964     // If we are in standard C/C++ mode, use the triple to decide on the default
2965     StringRef Env =
2966       getContext().getTargetInfo().getTriple().getEnvironmentName();
2967     if (Env == "device")
2968       DefaultCC = llvm::CallingConv::PTX_Device;
2969     else
2970       DefaultCC = llvm::CallingConv::PTX_Kernel;
2971   }
2972   FI.setEffectiveCallingConvention(DefaultCC);
2973 
2974 }
2975 
2976 llvm::Value *NVPTXABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
2977                                      CodeGenFunction &CFG) const {
2978   llvm_unreachable("NVPTX does not support varargs");
2979 }
2980 
2981 void NVPTXTargetCodeGenInfo::
2982 SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
2983                     CodeGen::CodeGenModule &M) const{
2984   const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
2985   if (!FD) return;
2986 
2987   llvm::Function *F = cast<llvm::Function>(GV);
2988 
2989   // Perform special handling in OpenCL mode
2990   if (M.getLangOpts().OpenCL) {
2991     // Use OpenCL function attributes to set proper calling conventions
2992     // By default, all functions are device functions
2993     if (FD->hasAttr<OpenCLKernelAttr>()) {
2994       // OpenCL __kernel functions get a kernel calling convention
2995       F->setCallingConv(llvm::CallingConv::PTX_Kernel);
2996       // And kernel functions are not subject to inlining
2997       F->addFnAttr(llvm::Attribute::NoInline);
2998     }
2999   }
3000 
3001   // Perform special handling in CUDA mode.
3002   if (M.getLangOpts().CUDA) {
3003     // CUDA __global__ functions get a kernel calling convention.  Since
3004     // __global__ functions cannot be called from the device, we do not
3005     // need to set the noinline attribute.
3006     if (FD->getAttr<CUDAGlobalAttr>())
3007       F->setCallingConv(llvm::CallingConv::PTX_Kernel);
3008   }
3009 }
3010 
3011 }
3012 
3013 //===----------------------------------------------------------------------===//
3014 // MBlaze ABI Implementation
3015 //===----------------------------------------------------------------------===//
3016 
3017 namespace {
3018 
3019 class MBlazeABIInfo : public ABIInfo {
3020 public:
3021   MBlazeABIInfo(CodeGenTypes &CGT) : ABIInfo(CGT) {}
3022 
3023   bool isPromotableIntegerType(QualType Ty) const;
3024 
3025   ABIArgInfo classifyReturnType(QualType RetTy) const;
3026   ABIArgInfo classifyArgumentType(QualType RetTy) const;
3027 
3028   virtual void computeInfo(CGFunctionInfo &FI) const {
3029     FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
3030     for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
3031          it != ie; ++it)
3032       it->info = classifyArgumentType(it->type);
3033   }
3034 
3035   virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
3036                                  CodeGenFunction &CGF) const;
3037 };
3038 
3039 class MBlazeTargetCodeGenInfo : public TargetCodeGenInfo {
3040 public:
3041   MBlazeTargetCodeGenInfo(CodeGenTypes &CGT)
3042     : TargetCodeGenInfo(new MBlazeABIInfo(CGT)) {}
3043   void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
3044                            CodeGen::CodeGenModule &M) const;
3045 };
3046 
3047 }
3048 
3049 bool MBlazeABIInfo::isPromotableIntegerType(QualType Ty) const {
3050   // MBlaze ABI requires all 8 and 16 bit quantities to be extended.
3051   if (const BuiltinType *BT = Ty->getAs<BuiltinType>())
3052     switch (BT->getKind()) {
3053     case BuiltinType::Bool:
3054     case BuiltinType::Char_S:
3055     case BuiltinType::Char_U:
3056     case BuiltinType::SChar:
3057     case BuiltinType::UChar:
3058     case BuiltinType::Short:
3059     case BuiltinType::UShort:
3060       return true;
3061     default:
3062       return false;
3063     }
3064   return false;
3065 }
3066 
3067 llvm::Value *MBlazeABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
3068                                       CodeGenFunction &CGF) const {
3069   // FIXME: Implement
3070   return 0;
3071 }
3072 
3073 
3074 ABIArgInfo MBlazeABIInfo::classifyReturnType(QualType RetTy) const {
3075   if (RetTy->isVoidType())
3076     return ABIArgInfo::getIgnore();
3077   if (isAggregateTypeForABI(RetTy))
3078     return ABIArgInfo::getIndirect(0);
3079 
3080   return (isPromotableIntegerType(RetTy) ?
3081           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
3082 }
3083 
3084 ABIArgInfo MBlazeABIInfo::classifyArgumentType(QualType Ty) const {
3085   if (isAggregateTypeForABI(Ty))
3086     return ABIArgInfo::getIndirect(0);
3087 
3088   return (isPromotableIntegerType(Ty) ?
3089           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
3090 }
3091 
3092 void MBlazeTargetCodeGenInfo::SetTargetAttributes(const Decl *D,
3093                                                   llvm::GlobalValue *GV,
3094                                                   CodeGen::CodeGenModule &M)
3095                                                   const {
3096   const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
3097   if (!FD) return;
3098 
3099   llvm::CallingConv::ID CC = llvm::CallingConv::C;
3100   if (FD->hasAttr<MBlazeInterruptHandlerAttr>())
3101     CC = llvm::CallingConv::MBLAZE_INTR;
3102   else if (FD->hasAttr<MBlazeSaveVolatilesAttr>())
3103     CC = llvm::CallingConv::MBLAZE_SVOL;
3104 
3105   if (CC != llvm::CallingConv::C) {
3106       // Handle 'interrupt_handler' attribute:
3107       llvm::Function *F = cast<llvm::Function>(GV);
3108 
3109       // Step 1: Set ISR calling convention.
3110       F->setCallingConv(CC);
3111 
3112       // Step 2: Add attributes goodness.
3113       F->addFnAttr(llvm::Attribute::NoInline);
3114   }
3115 
3116   // Step 3: Emit _interrupt_handler alias.
3117   if (CC == llvm::CallingConv::MBLAZE_INTR)
3118     new llvm::GlobalAlias(GV->getType(), llvm::Function::ExternalLinkage,
3119                           "_interrupt_handler", GV, &M.getModule());
3120 }
3121 
3122 
3123 //===----------------------------------------------------------------------===//
3124 // MSP430 ABI Implementation
3125 //===----------------------------------------------------------------------===//
3126 
3127 namespace {
3128 
3129 class MSP430TargetCodeGenInfo : public TargetCodeGenInfo {
3130 public:
3131   MSP430TargetCodeGenInfo(CodeGenTypes &CGT)
3132     : TargetCodeGenInfo(new DefaultABIInfo(CGT)) {}
3133   void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
3134                            CodeGen::CodeGenModule &M) const;
3135 };
3136 
3137 }
3138 
3139 void MSP430TargetCodeGenInfo::SetTargetAttributes(const Decl *D,
3140                                                   llvm::GlobalValue *GV,
3141                                              CodeGen::CodeGenModule &M) const {
3142   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
3143     if (const MSP430InterruptAttr *attr = FD->getAttr<MSP430InterruptAttr>()) {
3144       // Handle 'interrupt' attribute:
3145       llvm::Function *F = cast<llvm::Function>(GV);
3146 
3147       // Step 1: Set ISR calling convention.
3148       F->setCallingConv(llvm::CallingConv::MSP430_INTR);
3149 
3150       // Step 2: Add attributes goodness.
3151       F->addFnAttr(llvm::Attribute::NoInline);
3152 
3153       // Step 3: Emit ISR vector alias.
3154       unsigned Num = attr->getNumber() + 0xffe0;
3155       new llvm::GlobalAlias(GV->getType(), llvm::Function::ExternalLinkage,
3156                             "vector_" + Twine::utohexstr(Num),
3157                             GV, &M.getModule());
3158     }
3159   }
3160 }
3161 
3162 //===----------------------------------------------------------------------===//
3163 // MIPS ABI Implementation.  This works for both little-endian and
3164 // big-endian variants.
3165 //===----------------------------------------------------------------------===//
3166 
3167 namespace {
3168 class MipsABIInfo : public ABIInfo {
3169   bool IsO32;
3170   unsigned MinABIStackAlignInBytes, StackAlignInBytes;
3171   void CoerceToIntArgs(uint64_t TySize,
3172                        SmallVector<llvm::Type*, 8> &ArgList) const;
3173   llvm::Type* HandleAggregates(QualType Ty, uint64_t TySize) const;
3174   llvm::Type* returnAggregateInRegs(QualType RetTy, uint64_t Size) const;
3175   llvm::Type* getPaddingType(uint64_t Align, uint64_t Offset) const;
3176 public:
3177   MipsABIInfo(CodeGenTypes &CGT, bool _IsO32) :
3178     ABIInfo(CGT), IsO32(_IsO32), MinABIStackAlignInBytes(IsO32 ? 4 : 8),
3179     StackAlignInBytes(IsO32 ? 8 : 16) {}
3180 
3181   ABIArgInfo classifyReturnType(QualType RetTy) const;
3182   ABIArgInfo classifyArgumentType(QualType RetTy, uint64_t &Offset) const;
3183   virtual void computeInfo(CGFunctionInfo &FI) const;
3184   virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
3185                                  CodeGenFunction &CGF) const;
3186 };
3187 
3188 class MIPSTargetCodeGenInfo : public TargetCodeGenInfo {
3189   unsigned SizeOfUnwindException;
3190 public:
3191   MIPSTargetCodeGenInfo(CodeGenTypes &CGT, bool IsO32)
3192     : TargetCodeGenInfo(new MipsABIInfo(CGT, IsO32)),
3193       SizeOfUnwindException(IsO32 ? 24 : 32) {}
3194 
3195   int getDwarfEHStackPointer(CodeGen::CodeGenModule &CGM) const {
3196     return 29;
3197   }
3198 
3199   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
3200                                llvm::Value *Address) const;
3201 
3202   unsigned getSizeOfUnwindException() const {
3203     return SizeOfUnwindException;
3204   }
3205 };
3206 }
3207 
3208 void MipsABIInfo::CoerceToIntArgs(uint64_t TySize,
3209                                   SmallVector<llvm::Type*, 8> &ArgList) const {
3210   llvm::IntegerType *IntTy =
3211     llvm::IntegerType::get(getVMContext(), MinABIStackAlignInBytes * 8);
3212 
3213   // Add (TySize / MinABIStackAlignInBytes) args of IntTy.
3214   for (unsigned N = TySize / (MinABIStackAlignInBytes * 8); N; --N)
3215     ArgList.push_back(IntTy);
3216 
3217   // If necessary, add one more integer type to ArgList.
3218   unsigned R = TySize % (MinABIStackAlignInBytes * 8);
3219 
3220   if (R)
3221     ArgList.push_back(llvm::IntegerType::get(getVMContext(), R));
3222 }
3223 
3224 // In N32/64, an aligned double precision floating point field is passed in
3225 // a register.
3226 llvm::Type* MipsABIInfo::HandleAggregates(QualType Ty, uint64_t TySize) const {
3227   SmallVector<llvm::Type*, 8> ArgList, IntArgList;
3228 
3229   if (IsO32) {
3230     CoerceToIntArgs(TySize, ArgList);
3231     return llvm::StructType::get(getVMContext(), ArgList);
3232   }
3233 
3234   if (Ty->isComplexType())
3235     return CGT.ConvertType(Ty);
3236 
3237   const RecordType *RT = Ty->getAs<RecordType>();
3238 
3239   // Unions/vectors are passed in integer registers.
3240   if (!RT || !RT->isStructureOrClassType()) {
3241     CoerceToIntArgs(TySize, ArgList);
3242     return llvm::StructType::get(getVMContext(), ArgList);
3243   }
3244 
3245   const RecordDecl *RD = RT->getDecl();
3246   const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
3247   assert(!(TySize % 8) && "Size of structure must be multiple of 8.");
3248 
3249   uint64_t LastOffset = 0;
3250   unsigned idx = 0;
3251   llvm::IntegerType *I64 = llvm::IntegerType::get(getVMContext(), 64);
3252 
3253   // Iterate over fields in the struct/class and check if there are any aligned
3254   // double fields.
3255   for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
3256        i != e; ++i, ++idx) {
3257     const QualType Ty = i->getType();
3258     const BuiltinType *BT = Ty->getAs<BuiltinType>();
3259 
3260     if (!BT || BT->getKind() != BuiltinType::Double)
3261       continue;
3262 
3263     uint64_t Offset = Layout.getFieldOffset(idx);
3264     if (Offset % 64) // Ignore doubles that are not aligned.
3265       continue;
3266 
3267     // Add ((Offset - LastOffset) / 64) args of type i64.
3268     for (unsigned j = (Offset - LastOffset) / 64; j > 0; --j)
3269       ArgList.push_back(I64);
3270 
3271     // Add double type.
3272     ArgList.push_back(llvm::Type::getDoubleTy(getVMContext()));
3273     LastOffset = Offset + 64;
3274   }
3275 
3276   CoerceToIntArgs(TySize - LastOffset, IntArgList);
3277   ArgList.append(IntArgList.begin(), IntArgList.end());
3278 
3279   return llvm::StructType::get(getVMContext(), ArgList);
3280 }
3281 
3282 llvm::Type *MipsABIInfo::getPaddingType(uint64_t Align, uint64_t Offset) const {
3283   assert((Offset % MinABIStackAlignInBytes) == 0);
3284 
3285   if ((Align - 1) & Offset)
3286     return llvm::IntegerType::get(getVMContext(), MinABIStackAlignInBytes * 8);
3287 
3288   return 0;
3289 }
3290 
3291 ABIArgInfo
3292 MipsABIInfo::classifyArgumentType(QualType Ty, uint64_t &Offset) const {
3293   uint64_t OrigOffset = Offset;
3294   uint64_t TySize = getContext().getTypeSize(Ty);
3295   uint64_t Align = getContext().getTypeAlign(Ty) / 8;
3296 
3297   Align = std::min(std::max(Align, (uint64_t)MinABIStackAlignInBytes),
3298                    (uint64_t)StackAlignInBytes);
3299   Offset = llvm::RoundUpToAlignment(Offset, Align);
3300   Offset += llvm::RoundUpToAlignment(TySize, Align * 8) / 8;
3301 
3302   if (isAggregateTypeForABI(Ty) || Ty->isVectorType()) {
3303     // Ignore empty aggregates.
3304     if (TySize == 0)
3305       return ABIArgInfo::getIgnore();
3306 
3307     // Records with non trivial destructors/constructors should not be passed
3308     // by value.
3309     if (isRecordWithNonTrivialDestructorOrCopyConstructor(Ty)) {
3310       Offset = OrigOffset + MinABIStackAlignInBytes;
3311       return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
3312     }
3313 
3314     // If we have reached here, aggregates are passed directly by coercing to
3315     // another structure type. Padding is inserted if the offset of the
3316     // aggregate is unaligned.
3317     return ABIArgInfo::getDirect(HandleAggregates(Ty, TySize), 0,
3318                                  getPaddingType(Align, OrigOffset));
3319   }
3320 
3321   // Treat an enum type as its underlying type.
3322   if (const EnumType *EnumTy = Ty->getAs<EnumType>())
3323     Ty = EnumTy->getDecl()->getIntegerType();
3324 
3325   if (Ty->isPromotableIntegerType())
3326     return ABIArgInfo::getExtend();
3327 
3328   return ABIArgInfo::getDirect(0, 0, getPaddingType(Align, OrigOffset));
3329 }
3330 
3331 llvm::Type*
3332 MipsABIInfo::returnAggregateInRegs(QualType RetTy, uint64_t Size) const {
3333   const RecordType *RT = RetTy->getAs<RecordType>();
3334   SmallVector<llvm::Type*, 8> RTList;
3335 
3336   if (RT && RT->isStructureOrClassType()) {
3337     const RecordDecl *RD = RT->getDecl();
3338     const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
3339     unsigned FieldCnt = Layout.getFieldCount();
3340 
3341     // N32/64 returns struct/classes in floating point registers if the
3342     // following conditions are met:
3343     // 1. The size of the struct/class is no larger than 128-bit.
3344     // 2. The struct/class has one or two fields all of which are floating
3345     //    point types.
3346     // 3. The offset of the first field is zero (this follows what gcc does).
3347     //
3348     // Any other composite results are returned in integer registers.
3349     //
3350     if (FieldCnt && (FieldCnt <= 2) && !Layout.getFieldOffset(0)) {
3351       RecordDecl::field_iterator b = RD->field_begin(), e = RD->field_end();
3352       for (; b != e; ++b) {
3353         const BuiltinType *BT = b->getType()->getAs<BuiltinType>();
3354 
3355         if (!BT || !BT->isFloatingPoint())
3356           break;
3357 
3358         RTList.push_back(CGT.ConvertType(b->getType()));
3359       }
3360 
3361       if (b == e)
3362         return llvm::StructType::get(getVMContext(), RTList,
3363                                      RD->hasAttr<PackedAttr>());
3364 
3365       RTList.clear();
3366     }
3367   }
3368 
3369   CoerceToIntArgs(Size, RTList);
3370   return llvm::StructType::get(getVMContext(), RTList);
3371 }
3372 
3373 ABIArgInfo MipsABIInfo::classifyReturnType(QualType RetTy) const {
3374   uint64_t Size = getContext().getTypeSize(RetTy);
3375 
3376   if (RetTy->isVoidType() || Size == 0)
3377     return ABIArgInfo::getIgnore();
3378 
3379   if (isAggregateTypeForABI(RetTy) || RetTy->isVectorType()) {
3380     if (Size <= 128) {
3381       if (RetTy->isAnyComplexType())
3382         return ABIArgInfo::getDirect();
3383 
3384       // O32 returns integer vectors in registers.
3385       if (IsO32 && RetTy->isVectorType() && !RetTy->hasFloatingRepresentation())
3386         return ABIArgInfo::getDirect(returnAggregateInRegs(RetTy, Size));
3387 
3388       if (!IsO32 && !isRecordWithNonTrivialDestructorOrCopyConstructor(RetTy))
3389         return ABIArgInfo::getDirect(returnAggregateInRegs(RetTy, Size));
3390     }
3391 
3392     return ABIArgInfo::getIndirect(0);
3393   }
3394 
3395   // Treat an enum type as its underlying type.
3396   if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
3397     RetTy = EnumTy->getDecl()->getIntegerType();
3398 
3399   return (RetTy->isPromotableIntegerType() ?
3400           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
3401 }
3402 
3403 void MipsABIInfo::computeInfo(CGFunctionInfo &FI) const {
3404   ABIArgInfo &RetInfo = FI.getReturnInfo();
3405   RetInfo = classifyReturnType(FI.getReturnType());
3406 
3407   // Check if a pointer to an aggregate is passed as a hidden argument.
3408   uint64_t Offset = RetInfo.isIndirect() ? MinABIStackAlignInBytes : 0;
3409 
3410   for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
3411        it != ie; ++it)
3412     it->info = classifyArgumentType(it->type, Offset);
3413 }
3414 
3415 llvm::Value* MipsABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
3416                                     CodeGenFunction &CGF) const {
3417   llvm::Type *BP = CGF.Int8PtrTy;
3418   llvm::Type *BPP = CGF.Int8PtrPtrTy;
3419 
3420   CGBuilderTy &Builder = CGF.Builder;
3421   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP, "ap");
3422   llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
3423   int64_t TypeAlign = getContext().getTypeAlign(Ty) / 8;
3424   llvm::Type *PTy = llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
3425   llvm::Value *AddrTyped;
3426   unsigned PtrWidth = getContext().getTargetInfo().getPointerWidth(0);
3427   llvm::IntegerType *IntTy = (PtrWidth == 32) ? CGF.Int32Ty : CGF.Int64Ty;
3428 
3429   if (TypeAlign > MinABIStackAlignInBytes) {
3430     llvm::Value *AddrAsInt = CGF.Builder.CreatePtrToInt(Addr, IntTy);
3431     llvm::Value *Inc = llvm::ConstantInt::get(IntTy, TypeAlign - 1);
3432     llvm::Value *Mask = llvm::ConstantInt::get(IntTy, -TypeAlign);
3433     llvm::Value *Add = CGF.Builder.CreateAdd(AddrAsInt, Inc);
3434     llvm::Value *And = CGF.Builder.CreateAnd(Add, Mask);
3435     AddrTyped = CGF.Builder.CreateIntToPtr(And, PTy);
3436   }
3437   else
3438     AddrTyped = Builder.CreateBitCast(Addr, PTy);
3439 
3440   llvm::Value *AlignedAddr = Builder.CreateBitCast(AddrTyped, BP);
3441   TypeAlign = std::max((unsigned)TypeAlign, MinABIStackAlignInBytes);
3442   uint64_t Offset =
3443     llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, TypeAlign);
3444   llvm::Value *NextAddr =
3445     Builder.CreateGEP(AlignedAddr, llvm::ConstantInt::get(IntTy, Offset),
3446                       "ap.next");
3447   Builder.CreateStore(NextAddr, VAListAddrAsBPP);
3448 
3449   return AddrTyped;
3450 }
3451 
3452 bool
3453 MIPSTargetCodeGenInfo::initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
3454                                                llvm::Value *Address) const {
3455   // This information comes from gcc's implementation, which seems to
3456   // as canonical as it gets.
3457 
3458   // Everything on MIPS is 4 bytes.  Double-precision FP registers
3459   // are aliased to pairs of single-precision FP registers.
3460   llvm::Value *Four8 = llvm::ConstantInt::get(CGF.Int8Ty, 4);
3461 
3462   // 0-31 are the general purpose registers, $0 - $31.
3463   // 32-63 are the floating-point registers, $f0 - $f31.
3464   // 64 and 65 are the multiply/divide registers, $hi and $lo.
3465   // 66 is the (notional, I think) register for signal-handler return.
3466   AssignToArrayRange(CGF.Builder, Address, Four8, 0, 65);
3467 
3468   // 67-74 are the floating-point status registers, $fcc0 - $fcc7.
3469   // They are one bit wide and ignored here.
3470 
3471   // 80-111 are the coprocessor 0 registers, $c0r0 - $c0r31.
3472   // (coprocessor 1 is the FP unit)
3473   // 112-143 are the coprocessor 2 registers, $c2r0 - $c2r31.
3474   // 144-175 are the coprocessor 3 registers, $c3r0 - $c3r31.
3475   // 176-181 are the DSP accumulator registers.
3476   AssignToArrayRange(CGF.Builder, Address, Four8, 80, 181);
3477   return false;
3478 }
3479 
3480 //===----------------------------------------------------------------------===//
3481 // TCE ABI Implementation (see http://tce.cs.tut.fi). Uses mostly the defaults.
3482 // Currently subclassed only to implement custom OpenCL C function attribute
3483 // handling.
3484 //===----------------------------------------------------------------------===//
3485 
3486 namespace {
3487 
3488 class TCETargetCodeGenInfo : public DefaultTargetCodeGenInfo {
3489 public:
3490   TCETargetCodeGenInfo(CodeGenTypes &CGT)
3491     : DefaultTargetCodeGenInfo(CGT) {}
3492 
3493   virtual void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
3494                                    CodeGen::CodeGenModule &M) const;
3495 };
3496 
3497 void TCETargetCodeGenInfo::SetTargetAttributes(const Decl *D,
3498                                                llvm::GlobalValue *GV,
3499                                                CodeGen::CodeGenModule &M) const {
3500   const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
3501   if (!FD) return;
3502 
3503   llvm::Function *F = cast<llvm::Function>(GV);
3504 
3505   if (M.getLangOpts().OpenCL) {
3506     if (FD->hasAttr<OpenCLKernelAttr>()) {
3507       // OpenCL C Kernel functions are not subject to inlining
3508       F->addFnAttr(llvm::Attribute::NoInline);
3509 
3510       if (FD->hasAttr<ReqdWorkGroupSizeAttr>()) {
3511 
3512         // Convert the reqd_work_group_size() attributes to metadata.
3513         llvm::LLVMContext &Context = F->getContext();
3514         llvm::NamedMDNode *OpenCLMetadata =
3515             M.getModule().getOrInsertNamedMetadata("opencl.kernel_wg_size_info");
3516 
3517         SmallVector<llvm::Value*, 5> Operands;
3518         Operands.push_back(F);
3519 
3520         Operands.push_back(llvm::Constant::getIntegerValue(M.Int32Ty,
3521                              llvm::APInt(32,
3522                              FD->getAttr<ReqdWorkGroupSizeAttr>()->getXDim())));
3523         Operands.push_back(llvm::Constant::getIntegerValue(M.Int32Ty,
3524                              llvm::APInt(32,
3525                                FD->getAttr<ReqdWorkGroupSizeAttr>()->getYDim())));
3526         Operands.push_back(llvm::Constant::getIntegerValue(M.Int32Ty,
3527                              llvm::APInt(32,
3528                                FD->getAttr<ReqdWorkGroupSizeAttr>()->getZDim())));
3529 
3530         // Add a boolean constant operand for "required" (true) or "hint" (false)
3531         // for implementing the work_group_size_hint attr later. Currently
3532         // always true as the hint is not yet implemented.
3533         Operands.push_back(llvm::ConstantInt::getTrue(Context));
3534         OpenCLMetadata->addOperand(llvm::MDNode::get(Context, Operands));
3535       }
3536     }
3537   }
3538 }
3539 
3540 }
3541 
3542 //===----------------------------------------------------------------------===//
3543 // Hexagon ABI Implementation
3544 //===----------------------------------------------------------------------===//
3545 
3546 namespace {
3547 
3548 class HexagonABIInfo : public ABIInfo {
3549 
3550 
3551 public:
3552   HexagonABIInfo(CodeGenTypes &CGT) : ABIInfo(CGT) {}
3553 
3554 private:
3555 
3556   ABIArgInfo classifyReturnType(QualType RetTy) const;
3557   ABIArgInfo classifyArgumentType(QualType RetTy) const;
3558 
3559   virtual void computeInfo(CGFunctionInfo &FI) const;
3560 
3561   virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
3562                                  CodeGenFunction &CGF) const;
3563 };
3564 
3565 class HexagonTargetCodeGenInfo : public TargetCodeGenInfo {
3566 public:
3567   HexagonTargetCodeGenInfo(CodeGenTypes &CGT)
3568     :TargetCodeGenInfo(new HexagonABIInfo(CGT)) {}
3569 
3570   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const {
3571     return 29;
3572   }
3573 };
3574 
3575 }
3576 
3577 void HexagonABIInfo::computeInfo(CGFunctionInfo &FI) const {
3578   FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
3579   for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
3580        it != ie; ++it)
3581     it->info = classifyArgumentType(it->type);
3582 }
3583 
3584 ABIArgInfo HexagonABIInfo::classifyArgumentType(QualType Ty) const {
3585   if (!isAggregateTypeForABI(Ty)) {
3586     // Treat an enum type as its underlying type.
3587     if (const EnumType *EnumTy = Ty->getAs<EnumType>())
3588       Ty = EnumTy->getDecl()->getIntegerType();
3589 
3590     return (Ty->isPromotableIntegerType() ?
3591             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
3592   }
3593 
3594   // Ignore empty records.
3595   if (isEmptyRecord(getContext(), Ty, true))
3596     return ABIArgInfo::getIgnore();
3597 
3598   // Structures with either a non-trivial destructor or a non-trivial
3599   // copy constructor are always indirect.
3600   if (isRecordWithNonTrivialDestructorOrCopyConstructor(Ty))
3601     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
3602 
3603   uint64_t Size = getContext().getTypeSize(Ty);
3604   if (Size > 64)
3605     return ABIArgInfo::getIndirect(0, /*ByVal=*/true);
3606     // Pass in the smallest viable integer type.
3607   else if (Size > 32)
3608       return ABIArgInfo::getDirect(llvm::Type::getInt64Ty(getVMContext()));
3609   else if (Size > 16)
3610       return ABIArgInfo::getDirect(llvm::Type::getInt32Ty(getVMContext()));
3611   else if (Size > 8)
3612       return ABIArgInfo::getDirect(llvm::Type::getInt16Ty(getVMContext()));
3613   else
3614       return ABIArgInfo::getDirect(llvm::Type::getInt8Ty(getVMContext()));
3615 }
3616 
3617 ABIArgInfo HexagonABIInfo::classifyReturnType(QualType RetTy) const {
3618   if (RetTy->isVoidType())
3619     return ABIArgInfo::getIgnore();
3620 
3621   // Large vector types should be returned via memory.
3622   if (RetTy->isVectorType() && getContext().getTypeSize(RetTy) > 64)
3623     return ABIArgInfo::getIndirect(0);
3624 
3625   if (!isAggregateTypeForABI(RetTy)) {
3626     // Treat an enum type as its underlying type.
3627     if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
3628       RetTy = EnumTy->getDecl()->getIntegerType();
3629 
3630     return (RetTy->isPromotableIntegerType() ?
3631             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
3632   }
3633 
3634   // Structures with either a non-trivial destructor or a non-trivial
3635   // copy constructor are always indirect.
3636   if (isRecordWithNonTrivialDestructorOrCopyConstructor(RetTy))
3637     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
3638 
3639   if (isEmptyRecord(getContext(), RetTy, true))
3640     return ABIArgInfo::getIgnore();
3641 
3642   // Aggregates <= 8 bytes are returned in r0; other aggregates
3643   // are returned indirectly.
3644   uint64_t Size = getContext().getTypeSize(RetTy);
3645   if (Size <= 64) {
3646     // Return in the smallest viable integer type.
3647     if (Size <= 8)
3648       return ABIArgInfo::getDirect(llvm::Type::getInt8Ty(getVMContext()));
3649     if (Size <= 16)
3650       return ABIArgInfo::getDirect(llvm::Type::getInt16Ty(getVMContext()));
3651     if (Size <= 32)
3652       return ABIArgInfo::getDirect(llvm::Type::getInt32Ty(getVMContext()));
3653     return ABIArgInfo::getDirect(llvm::Type::getInt64Ty(getVMContext()));
3654   }
3655 
3656   return ABIArgInfo::getIndirect(0, /*ByVal=*/true);
3657 }
3658 
3659 llvm::Value *HexagonABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
3660                                        CodeGenFunction &CGF) const {
3661   // FIXME: Need to handle alignment
3662   llvm::Type *BPP = CGF.Int8PtrPtrTy;
3663 
3664   CGBuilderTy &Builder = CGF.Builder;
3665   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP,
3666                                                        "ap");
3667   llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
3668   llvm::Type *PTy =
3669     llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
3670   llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy);
3671 
3672   uint64_t Offset =
3673     llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, 4);
3674   llvm::Value *NextAddr =
3675     Builder.CreateGEP(Addr, llvm::ConstantInt::get(CGF.Int32Ty, Offset),
3676                       "ap.next");
3677   Builder.CreateStore(NextAddr, VAListAddrAsBPP);
3678 
3679   return AddrTyped;
3680 }
3681 
3682 
3683 const TargetCodeGenInfo &CodeGenModule::getTargetCodeGenInfo() {
3684   if (TheTargetCodeGenInfo)
3685     return *TheTargetCodeGenInfo;
3686 
3687   const llvm::Triple &Triple = getContext().getTargetInfo().getTriple();
3688   switch (Triple.getArch()) {
3689   default:
3690     return *(TheTargetCodeGenInfo = new DefaultTargetCodeGenInfo(Types));
3691 
3692   case llvm::Triple::mips:
3693   case llvm::Triple::mipsel:
3694     return *(TheTargetCodeGenInfo = new MIPSTargetCodeGenInfo(Types, true));
3695 
3696   case llvm::Triple::mips64:
3697   case llvm::Triple::mips64el:
3698     return *(TheTargetCodeGenInfo = new MIPSTargetCodeGenInfo(Types, false));
3699 
3700   case llvm::Triple::arm:
3701   case llvm::Triple::thumb:
3702     {
3703       ARMABIInfo::ABIKind Kind = ARMABIInfo::AAPCS;
3704 
3705       if (strcmp(getContext().getTargetInfo().getABI(), "apcs-gnu") == 0)
3706         Kind = ARMABIInfo::APCS;
3707       else if (CodeGenOpts.FloatABI == "hard")
3708         Kind = ARMABIInfo::AAPCS_VFP;
3709 
3710       return *(TheTargetCodeGenInfo = new ARMTargetCodeGenInfo(Types, Kind));
3711     }
3712 
3713   case llvm::Triple::ppc:
3714     return *(TheTargetCodeGenInfo = new PPC32TargetCodeGenInfo(Types));
3715   case llvm::Triple::ppc64:
3716     return *(TheTargetCodeGenInfo = new PPC64TargetCodeGenInfo(Types));
3717 
3718   case llvm::Triple::nvptx:
3719   case llvm::Triple::nvptx64:
3720     return *(TheTargetCodeGenInfo = new NVPTXTargetCodeGenInfo(Types));
3721 
3722   case llvm::Triple::mblaze:
3723     return *(TheTargetCodeGenInfo = new MBlazeTargetCodeGenInfo(Types));
3724 
3725   case llvm::Triple::msp430:
3726     return *(TheTargetCodeGenInfo = new MSP430TargetCodeGenInfo(Types));
3727 
3728   case llvm::Triple::tce:
3729     return *(TheTargetCodeGenInfo = new TCETargetCodeGenInfo(Types));
3730 
3731   case llvm::Triple::x86: {
3732     bool DisableMMX = strcmp(getContext().getTargetInfo().getABI(), "no-mmx") == 0;
3733 
3734     if (Triple.isOSDarwin())
3735       return *(TheTargetCodeGenInfo =
3736                new X86_32TargetCodeGenInfo(
3737                  Types, true, true, DisableMMX, false));
3738 
3739     switch (Triple.getOS()) {
3740     case llvm::Triple::Cygwin:
3741     case llvm::Triple::MinGW32:
3742     case llvm::Triple::AuroraUX:
3743     case llvm::Triple::DragonFly:
3744     case llvm::Triple::FreeBSD:
3745     case llvm::Triple::OpenBSD:
3746       return *(TheTargetCodeGenInfo =
3747                new X86_32TargetCodeGenInfo(
3748                  Types, false, true, DisableMMX, false));
3749 
3750     case llvm::Triple::Win32:
3751       return *(TheTargetCodeGenInfo =
3752                new X86_32TargetCodeGenInfo(
3753                  Types, false, true, DisableMMX, true));
3754 
3755     default:
3756       return *(TheTargetCodeGenInfo =
3757                new X86_32TargetCodeGenInfo(
3758                  Types, false, false, DisableMMX, false));
3759     }
3760   }
3761 
3762   case llvm::Triple::x86_64: {
3763     bool HasAVX = strcmp(getContext().getTargetInfo().getABI(), "avx") == 0;
3764 
3765     switch (Triple.getOS()) {
3766     case llvm::Triple::Win32:
3767     case llvm::Triple::MinGW32:
3768     case llvm::Triple::Cygwin:
3769       return *(TheTargetCodeGenInfo = new WinX86_64TargetCodeGenInfo(Types));
3770     default:
3771       return *(TheTargetCodeGenInfo = new X86_64TargetCodeGenInfo(Types,
3772                                                                   HasAVX));
3773     }
3774   }
3775   case llvm::Triple::hexagon:
3776     return *(TheTargetCodeGenInfo = new HexagonTargetCodeGenInfo(Types));
3777   }
3778 }
3779