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 = OffsetBase + Layout.getBaseClassOffsetInBits(Base);
1354         classify(i->getType(), Offset, FieldLo, FieldHi);
1355         Lo = merge(Lo, FieldLo);
1356         Hi = merge(Hi, FieldHi);
1357         if (Lo == Memory || Hi == Memory)
1358           break;
1359       }
1360     }
1361 
1362     // Classify the fields one at a time, merging the results.
1363     unsigned idx = 0;
1364     for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
1365            i != e; ++i, ++idx) {
1366       uint64_t Offset = OffsetBase + Layout.getFieldOffset(idx);
1367       bool BitField = i->isBitField();
1368 
1369       // AMD64-ABI 3.2.3p2: Rule 1. If the size of an object is larger than
1370       // four eightbytes, or it contains unaligned fields, it has class MEMORY.
1371       //
1372       // The only case a 256-bit wide vector could be used is when the struct
1373       // contains a single 256-bit element. Since Lo and Hi logic isn't extended
1374       // to work for sizes wider than 128, early check and fallback to memory.
1375       //
1376       if (Size > 128 && getContext().getTypeSize(i->getType()) != 256) {
1377         Lo = Memory;
1378         return;
1379       }
1380       // Note, skip this test for bit-fields, see below.
1381       if (!BitField && Offset % getContext().getTypeAlign(i->getType())) {
1382         Lo = Memory;
1383         return;
1384       }
1385 
1386       // Classify this field.
1387       //
1388       // AMD64-ABI 3.2.3p2: Rule 3. If the size of the aggregate
1389       // exceeds a single eightbyte, each is classified
1390       // separately. Each eightbyte gets initialized to class
1391       // NO_CLASS.
1392       Class FieldLo, FieldHi;
1393 
1394       // Bit-fields require special handling, they do not force the
1395       // structure to be passed in memory even if unaligned, and
1396       // therefore they can straddle an eightbyte.
1397       if (BitField) {
1398         // Ignore padding bit-fields.
1399         if (i->isUnnamedBitfield())
1400           continue;
1401 
1402         uint64_t Offset = OffsetBase + Layout.getFieldOffset(idx);
1403         uint64_t Size = i->getBitWidthValue(getContext());
1404 
1405         uint64_t EB_Lo = Offset / 64;
1406         uint64_t EB_Hi = (Offset + Size - 1) / 64;
1407         FieldLo = FieldHi = NoClass;
1408         if (EB_Lo) {
1409           assert(EB_Hi == EB_Lo && "Invalid classification, type > 16 bytes.");
1410           FieldLo = NoClass;
1411           FieldHi = Integer;
1412         } else {
1413           FieldLo = Integer;
1414           FieldHi = EB_Hi ? Integer : NoClass;
1415         }
1416       } else
1417         classify(i->getType(), Offset, FieldLo, FieldHi);
1418       Lo = merge(Lo, FieldLo);
1419       Hi = merge(Hi, FieldHi);
1420       if (Lo == Memory || Hi == Memory)
1421         break;
1422     }
1423 
1424     postMerge(Size, Lo, Hi);
1425   }
1426 }
1427 
1428 ABIArgInfo X86_64ABIInfo::getIndirectReturnResult(QualType Ty) const {
1429   // If this is a scalar LLVM value then assume LLVM will pass it in the right
1430   // place naturally.
1431   if (!isAggregateTypeForABI(Ty)) {
1432     // Treat an enum type as its underlying type.
1433     if (const EnumType *EnumTy = Ty->getAs<EnumType>())
1434       Ty = EnumTy->getDecl()->getIntegerType();
1435 
1436     return (Ty->isPromotableIntegerType() ?
1437             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
1438   }
1439 
1440   return ABIArgInfo::getIndirect(0);
1441 }
1442 
1443 bool X86_64ABIInfo::IsIllegalVectorType(QualType Ty) const {
1444   if (const VectorType *VecTy = Ty->getAs<VectorType>()) {
1445     uint64_t Size = getContext().getTypeSize(VecTy);
1446     unsigned LargestVector = HasAVX ? 256 : 128;
1447     if (Size <= 64 || Size > LargestVector)
1448       return true;
1449   }
1450 
1451   return false;
1452 }
1453 
1454 ABIArgInfo X86_64ABIInfo::getIndirectResult(QualType Ty,
1455                                             unsigned freeIntRegs) const {
1456   // If this is a scalar LLVM value then assume LLVM will pass it in the right
1457   // place naturally.
1458   //
1459   // This assumption is optimistic, as there could be free registers available
1460   // when we need to pass this argument in memory, and LLVM could try to pass
1461   // the argument in the free register. This does not seem to happen currently,
1462   // but this code would be much safer if we could mark the argument with
1463   // 'onstack'. See PR12193.
1464   if (!isAggregateTypeForABI(Ty) && !IsIllegalVectorType(Ty)) {
1465     // Treat an enum type as its underlying type.
1466     if (const EnumType *EnumTy = Ty->getAs<EnumType>())
1467       Ty = EnumTy->getDecl()->getIntegerType();
1468 
1469     return (Ty->isPromotableIntegerType() ?
1470             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
1471   }
1472 
1473   if (isRecordWithNonTrivialDestructorOrCopyConstructor(Ty))
1474     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
1475 
1476   // Compute the byval alignment. We specify the alignment of the byval in all
1477   // cases so that the mid-level optimizer knows the alignment of the byval.
1478   unsigned Align = std::max(getContext().getTypeAlign(Ty) / 8, 8U);
1479 
1480   // Attempt to avoid passing indirect results using byval when possible. This
1481   // is important for good codegen.
1482   //
1483   // We do this by coercing the value into a scalar type which the backend can
1484   // handle naturally (i.e., without using byval).
1485   //
1486   // For simplicity, we currently only do this when we have exhausted all of the
1487   // free integer registers. Doing this when there are free integer registers
1488   // would require more care, as we would have to ensure that the coerced value
1489   // did not claim the unused register. That would require either reording the
1490   // arguments to the function (so that any subsequent inreg values came first),
1491   // or only doing this optimization when there were no following arguments that
1492   // might be inreg.
1493   //
1494   // We currently expect it to be rare (particularly in well written code) for
1495   // arguments to be passed on the stack when there are still free integer
1496   // registers available (this would typically imply large structs being passed
1497   // by value), so this seems like a fair tradeoff for now.
1498   //
1499   // We can revisit this if the backend grows support for 'onstack' parameter
1500   // attributes. See PR12193.
1501   if (freeIntRegs == 0) {
1502     uint64_t Size = getContext().getTypeSize(Ty);
1503 
1504     // If this type fits in an eightbyte, coerce it into the matching integral
1505     // type, which will end up on the stack (with alignment 8).
1506     if (Align == 8 && Size <= 64)
1507       return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),
1508                                                           Size));
1509   }
1510 
1511   return ABIArgInfo::getIndirect(Align);
1512 }
1513 
1514 /// GetByteVectorType - The ABI specifies that a value should be passed in an
1515 /// full vector XMM/YMM register.  Pick an LLVM IR type that will be passed as a
1516 /// vector register.
1517 llvm::Type *X86_64ABIInfo::GetByteVectorType(QualType Ty) const {
1518   llvm::Type *IRType = CGT.ConvertType(Ty);
1519 
1520   // Wrapper structs that just contain vectors are passed just like vectors,
1521   // strip them off if present.
1522   llvm::StructType *STy = dyn_cast<llvm::StructType>(IRType);
1523   while (STy && STy->getNumElements() == 1) {
1524     IRType = STy->getElementType(0);
1525     STy = dyn_cast<llvm::StructType>(IRType);
1526   }
1527 
1528   // If the preferred type is a 16-byte vector, prefer to pass it.
1529   if (llvm::VectorType *VT = dyn_cast<llvm::VectorType>(IRType)){
1530     llvm::Type *EltTy = VT->getElementType();
1531     unsigned BitWidth = VT->getBitWidth();
1532     if ((BitWidth >= 128 && BitWidth <= 256) &&
1533         (EltTy->isFloatTy() || EltTy->isDoubleTy() ||
1534          EltTy->isIntegerTy(8) || EltTy->isIntegerTy(16) ||
1535          EltTy->isIntegerTy(32) || EltTy->isIntegerTy(64) ||
1536          EltTy->isIntegerTy(128)))
1537       return VT;
1538   }
1539 
1540   return llvm::VectorType::get(llvm::Type::getDoubleTy(getVMContext()), 2);
1541 }
1542 
1543 /// BitsContainNoUserData - Return true if the specified [start,end) bit range
1544 /// is known to either be off the end of the specified type or being in
1545 /// alignment padding.  The user type specified is known to be at most 128 bits
1546 /// in size, and have passed through X86_64ABIInfo::classify with a successful
1547 /// classification that put one of the two halves in the INTEGER class.
1548 ///
1549 /// It is conservatively correct to return false.
1550 static bool BitsContainNoUserData(QualType Ty, unsigned StartBit,
1551                                   unsigned EndBit, ASTContext &Context) {
1552   // If the bytes being queried are off the end of the type, there is no user
1553   // data hiding here.  This handles analysis of builtins, vectors and other
1554   // types that don't contain interesting padding.
1555   unsigned TySize = (unsigned)Context.getTypeSize(Ty);
1556   if (TySize <= StartBit)
1557     return true;
1558 
1559   if (const ConstantArrayType *AT = Context.getAsConstantArrayType(Ty)) {
1560     unsigned EltSize = (unsigned)Context.getTypeSize(AT->getElementType());
1561     unsigned NumElts = (unsigned)AT->getSize().getZExtValue();
1562 
1563     // Check each element to see if the element overlaps with the queried range.
1564     for (unsigned i = 0; i != NumElts; ++i) {
1565       // If the element is after the span we care about, then we're done..
1566       unsigned EltOffset = i*EltSize;
1567       if (EltOffset >= EndBit) break;
1568 
1569       unsigned EltStart = EltOffset < StartBit ? StartBit-EltOffset :0;
1570       if (!BitsContainNoUserData(AT->getElementType(), EltStart,
1571                                  EndBit-EltOffset, Context))
1572         return false;
1573     }
1574     // If it overlaps no elements, then it is safe to process as padding.
1575     return true;
1576   }
1577 
1578   if (const RecordType *RT = Ty->getAs<RecordType>()) {
1579     const RecordDecl *RD = RT->getDecl();
1580     const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
1581 
1582     // If this is a C++ record, check the bases first.
1583     if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
1584       for (CXXRecordDecl::base_class_const_iterator i = CXXRD->bases_begin(),
1585            e = CXXRD->bases_end(); i != e; ++i) {
1586         assert(!i->isVirtual() && !i->getType()->isDependentType() &&
1587                "Unexpected base class!");
1588         const CXXRecordDecl *Base =
1589           cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
1590 
1591         // If the base is after the span we care about, ignore it.
1592         unsigned BaseOffset = (unsigned)Layout.getBaseClassOffsetInBits(Base);
1593         if (BaseOffset >= EndBit) continue;
1594 
1595         unsigned BaseStart = BaseOffset < StartBit ? StartBit-BaseOffset :0;
1596         if (!BitsContainNoUserData(i->getType(), BaseStart,
1597                                    EndBit-BaseOffset, Context))
1598           return false;
1599       }
1600     }
1601 
1602     // Verify that no field has data that overlaps the region of interest.  Yes
1603     // this could be sped up a lot by being smarter about queried fields,
1604     // however we're only looking at structs up to 16 bytes, so we don't care
1605     // much.
1606     unsigned idx = 0;
1607     for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
1608          i != e; ++i, ++idx) {
1609       unsigned FieldOffset = (unsigned)Layout.getFieldOffset(idx);
1610 
1611       // If we found a field after the region we care about, then we're done.
1612       if (FieldOffset >= EndBit) break;
1613 
1614       unsigned FieldStart = FieldOffset < StartBit ? StartBit-FieldOffset :0;
1615       if (!BitsContainNoUserData(i->getType(), FieldStart, EndBit-FieldOffset,
1616                                  Context))
1617         return false;
1618     }
1619 
1620     // If nothing in this record overlapped the area of interest, then we're
1621     // clean.
1622     return true;
1623   }
1624 
1625   return false;
1626 }
1627 
1628 /// ContainsFloatAtOffset - Return true if the specified LLVM IR type has a
1629 /// float member at the specified offset.  For example, {int,{float}} has a
1630 /// float at offset 4.  It is conservatively correct for this routine to return
1631 /// false.
1632 static bool ContainsFloatAtOffset(llvm::Type *IRType, unsigned IROffset,
1633                                   const llvm::TargetData &TD) {
1634   // Base case if we find a float.
1635   if (IROffset == 0 && IRType->isFloatTy())
1636     return true;
1637 
1638   // If this is a struct, recurse into the field at the specified offset.
1639   if (llvm::StructType *STy = dyn_cast<llvm::StructType>(IRType)) {
1640     const llvm::StructLayout *SL = TD.getStructLayout(STy);
1641     unsigned Elt = SL->getElementContainingOffset(IROffset);
1642     IROffset -= SL->getElementOffset(Elt);
1643     return ContainsFloatAtOffset(STy->getElementType(Elt), IROffset, TD);
1644   }
1645 
1646   // If this is an array, recurse into the field at the specified offset.
1647   if (llvm::ArrayType *ATy = dyn_cast<llvm::ArrayType>(IRType)) {
1648     llvm::Type *EltTy = ATy->getElementType();
1649     unsigned EltSize = TD.getTypeAllocSize(EltTy);
1650     IROffset -= IROffset/EltSize*EltSize;
1651     return ContainsFloatAtOffset(EltTy, IROffset, TD);
1652   }
1653 
1654   return false;
1655 }
1656 
1657 
1658 /// GetSSETypeAtOffset - Return a type that will be passed by the backend in the
1659 /// low 8 bytes of an XMM register, corresponding to the SSE class.
1660 llvm::Type *X86_64ABIInfo::
1661 GetSSETypeAtOffset(llvm::Type *IRType, unsigned IROffset,
1662                    QualType SourceTy, unsigned SourceOffset) const {
1663   // The only three choices we have are either double, <2 x float>, or float. We
1664   // pass as float if the last 4 bytes is just padding.  This happens for
1665   // structs that contain 3 floats.
1666   if (BitsContainNoUserData(SourceTy, SourceOffset*8+32,
1667                             SourceOffset*8+64, getContext()))
1668     return llvm::Type::getFloatTy(getVMContext());
1669 
1670   // We want to pass as <2 x float> if the LLVM IR type contains a float at
1671   // offset+0 and offset+4.  Walk the LLVM IR type to find out if this is the
1672   // case.
1673   if (ContainsFloatAtOffset(IRType, IROffset, getTargetData()) &&
1674       ContainsFloatAtOffset(IRType, IROffset+4, getTargetData()))
1675     return llvm::VectorType::get(llvm::Type::getFloatTy(getVMContext()), 2);
1676 
1677   return llvm::Type::getDoubleTy(getVMContext());
1678 }
1679 
1680 
1681 /// GetINTEGERTypeAtOffset - The ABI specifies that a value should be passed in
1682 /// an 8-byte GPR.  This means that we either have a scalar or we are talking
1683 /// about the high or low part of an up-to-16-byte struct.  This routine picks
1684 /// the best LLVM IR type to represent this, which may be i64 or may be anything
1685 /// else that the backend will pass in a GPR that works better (e.g. i8, %foo*,
1686 /// etc).
1687 ///
1688 /// PrefType is an LLVM IR type that corresponds to (part of) the IR type for
1689 /// the source type.  IROffset is an offset in bytes into the LLVM IR type that
1690 /// the 8-byte value references.  PrefType may be null.
1691 ///
1692 /// SourceTy is the source level type for the entire argument.  SourceOffset is
1693 /// an offset into this that we're processing (which is always either 0 or 8).
1694 ///
1695 llvm::Type *X86_64ABIInfo::
1696 GetINTEGERTypeAtOffset(llvm::Type *IRType, unsigned IROffset,
1697                        QualType SourceTy, unsigned SourceOffset) const {
1698   // If we're dealing with an un-offset LLVM IR type, then it means that we're
1699   // returning an 8-byte unit starting with it.  See if we can safely use it.
1700   if (IROffset == 0) {
1701     // Pointers and int64's always fill the 8-byte unit.
1702     if (isa<llvm::PointerType>(IRType) || IRType->isIntegerTy(64))
1703       return IRType;
1704 
1705     // If we have a 1/2/4-byte integer, we can use it only if the rest of the
1706     // goodness in the source type is just tail padding.  This is allowed to
1707     // kick in for struct {double,int} on the int, but not on
1708     // struct{double,int,int} because we wouldn't return the second int.  We
1709     // have to do this analysis on the source type because we can't depend on
1710     // unions being lowered a specific way etc.
1711     if (IRType->isIntegerTy(8) || IRType->isIntegerTy(16) ||
1712         IRType->isIntegerTy(32)) {
1713       unsigned BitWidth = cast<llvm::IntegerType>(IRType)->getBitWidth();
1714 
1715       if (BitsContainNoUserData(SourceTy, SourceOffset*8+BitWidth,
1716                                 SourceOffset*8+64, getContext()))
1717         return IRType;
1718     }
1719   }
1720 
1721   if (llvm::StructType *STy = dyn_cast<llvm::StructType>(IRType)) {
1722     // If this is a struct, recurse into the field at the specified offset.
1723     const llvm::StructLayout *SL = getTargetData().getStructLayout(STy);
1724     if (IROffset < SL->getSizeInBytes()) {
1725       unsigned FieldIdx = SL->getElementContainingOffset(IROffset);
1726       IROffset -= SL->getElementOffset(FieldIdx);
1727 
1728       return GetINTEGERTypeAtOffset(STy->getElementType(FieldIdx), IROffset,
1729                                     SourceTy, SourceOffset);
1730     }
1731   }
1732 
1733   if (llvm::ArrayType *ATy = dyn_cast<llvm::ArrayType>(IRType)) {
1734     llvm::Type *EltTy = ATy->getElementType();
1735     unsigned EltSize = getTargetData().getTypeAllocSize(EltTy);
1736     unsigned EltOffset = IROffset/EltSize*EltSize;
1737     return GetINTEGERTypeAtOffset(EltTy, IROffset-EltOffset, SourceTy,
1738                                   SourceOffset);
1739   }
1740 
1741   // Okay, we don't have any better idea of what to pass, so we pass this in an
1742   // integer register that isn't too big to fit the rest of the struct.
1743   unsigned TySizeInBytes =
1744     (unsigned)getContext().getTypeSizeInChars(SourceTy).getQuantity();
1745 
1746   assert(TySizeInBytes != SourceOffset && "Empty field?");
1747 
1748   // It is always safe to classify this as an integer type up to i64 that
1749   // isn't larger than the structure.
1750   return llvm::IntegerType::get(getVMContext(),
1751                                 std::min(TySizeInBytes-SourceOffset, 8U)*8);
1752 }
1753 
1754 
1755 /// GetX86_64ByValArgumentPair - Given a high and low type that can ideally
1756 /// be used as elements of a two register pair to pass or return, return a
1757 /// first class aggregate to represent them.  For example, if the low part of
1758 /// a by-value argument should be passed as i32* and the high part as float,
1759 /// return {i32*, float}.
1760 static llvm::Type *
1761 GetX86_64ByValArgumentPair(llvm::Type *Lo, llvm::Type *Hi,
1762                            const llvm::TargetData &TD) {
1763   // In order to correctly satisfy the ABI, we need to the high part to start
1764   // at offset 8.  If the high and low parts we inferred are both 4-byte types
1765   // (e.g. i32 and i32) then the resultant struct type ({i32,i32}) won't have
1766   // the second element at offset 8.  Check for this:
1767   unsigned LoSize = (unsigned)TD.getTypeAllocSize(Lo);
1768   unsigned HiAlign = TD.getABITypeAlignment(Hi);
1769   unsigned HiStart = llvm::TargetData::RoundUpAlignment(LoSize, HiAlign);
1770   assert(HiStart != 0 && HiStart <= 8 && "Invalid x86-64 argument pair!");
1771 
1772   // To handle this, we have to increase the size of the low part so that the
1773   // second element will start at an 8 byte offset.  We can't increase the size
1774   // of the second element because it might make us access off the end of the
1775   // struct.
1776   if (HiStart != 8) {
1777     // There are only two sorts of types the ABI generation code can produce for
1778     // the low part of a pair that aren't 8 bytes in size: float or i8/i16/i32.
1779     // Promote these to a larger type.
1780     if (Lo->isFloatTy())
1781       Lo = llvm::Type::getDoubleTy(Lo->getContext());
1782     else {
1783       assert(Lo->isIntegerTy() && "Invalid/unknown lo type");
1784       Lo = llvm::Type::getInt64Ty(Lo->getContext());
1785     }
1786   }
1787 
1788   llvm::StructType *Result = llvm::StructType::get(Lo, Hi, NULL);
1789 
1790 
1791   // Verify that the second element is at an 8-byte offset.
1792   assert(TD.getStructLayout(Result)->getElementOffset(1) == 8 &&
1793          "Invalid x86-64 argument pair!");
1794   return Result;
1795 }
1796 
1797 ABIArgInfo X86_64ABIInfo::
1798 classifyReturnType(QualType RetTy) const {
1799   // AMD64-ABI 3.2.3p4: Rule 1. Classify the return type with the
1800   // classification algorithm.
1801   X86_64ABIInfo::Class Lo, Hi;
1802   classify(RetTy, 0, Lo, Hi);
1803 
1804   // Check some invariants.
1805   assert((Hi != Memory || Lo == Memory) && "Invalid memory classification.");
1806   assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp classification.");
1807 
1808   llvm::Type *ResType = 0;
1809   switch (Lo) {
1810   case NoClass:
1811     if (Hi == NoClass)
1812       return ABIArgInfo::getIgnore();
1813     // If the low part is just padding, it takes no register, leave ResType
1814     // null.
1815     assert((Hi == SSE || Hi == Integer || Hi == X87Up) &&
1816            "Unknown missing lo part");
1817     break;
1818 
1819   case SSEUp:
1820   case X87Up:
1821     llvm_unreachable("Invalid classification for lo word.");
1822 
1823     // AMD64-ABI 3.2.3p4: Rule 2. Types of class memory are returned via
1824     // hidden argument.
1825   case Memory:
1826     return getIndirectReturnResult(RetTy);
1827 
1828     // AMD64-ABI 3.2.3p4: Rule 3. If the class is INTEGER, the next
1829     // available register of the sequence %rax, %rdx is used.
1830   case Integer:
1831     ResType = GetINTEGERTypeAtOffset(CGT.ConvertType(RetTy), 0, RetTy, 0);
1832 
1833     // If we have a sign or zero extended integer, make sure to return Extend
1834     // so that the parameter gets the right LLVM IR attributes.
1835     if (Hi == NoClass && isa<llvm::IntegerType>(ResType)) {
1836       // Treat an enum type as its underlying type.
1837       if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
1838         RetTy = EnumTy->getDecl()->getIntegerType();
1839 
1840       if (RetTy->isIntegralOrEnumerationType() &&
1841           RetTy->isPromotableIntegerType())
1842         return ABIArgInfo::getExtend();
1843     }
1844     break;
1845 
1846     // AMD64-ABI 3.2.3p4: Rule 4. If the class is SSE, the next
1847     // available SSE register of the sequence %xmm0, %xmm1 is used.
1848   case SSE:
1849     ResType = GetSSETypeAtOffset(CGT.ConvertType(RetTy), 0, RetTy, 0);
1850     break;
1851 
1852     // AMD64-ABI 3.2.3p4: Rule 6. If the class is X87, the value is
1853     // returned on the X87 stack in %st0 as 80-bit x87 number.
1854   case X87:
1855     ResType = llvm::Type::getX86_FP80Ty(getVMContext());
1856     break;
1857 
1858     // AMD64-ABI 3.2.3p4: Rule 8. If the class is COMPLEX_X87, the real
1859     // part of the value is returned in %st0 and the imaginary part in
1860     // %st1.
1861   case ComplexX87:
1862     assert(Hi == ComplexX87 && "Unexpected ComplexX87 classification.");
1863     ResType = llvm::StructType::get(llvm::Type::getX86_FP80Ty(getVMContext()),
1864                                     llvm::Type::getX86_FP80Ty(getVMContext()),
1865                                     NULL);
1866     break;
1867   }
1868 
1869   llvm::Type *HighPart = 0;
1870   switch (Hi) {
1871     // Memory was handled previously and X87 should
1872     // never occur as a hi class.
1873   case Memory:
1874   case X87:
1875     llvm_unreachable("Invalid classification for hi word.");
1876 
1877   case ComplexX87: // Previously handled.
1878   case NoClass:
1879     break;
1880 
1881   case Integer:
1882     HighPart = GetINTEGERTypeAtOffset(CGT.ConvertType(RetTy), 8, RetTy, 8);
1883     if (Lo == NoClass)  // Return HighPart at offset 8 in memory.
1884       return ABIArgInfo::getDirect(HighPart, 8);
1885     break;
1886   case SSE:
1887     HighPart = GetSSETypeAtOffset(CGT.ConvertType(RetTy), 8, RetTy, 8);
1888     if (Lo == NoClass)  // Return HighPart at offset 8 in memory.
1889       return ABIArgInfo::getDirect(HighPart, 8);
1890     break;
1891 
1892     // AMD64-ABI 3.2.3p4: Rule 5. If the class is SSEUP, the eightbyte
1893     // is passed in the next available eightbyte chunk if the last used
1894     // vector register.
1895     //
1896     // SSEUP should always be preceded by SSE, just widen.
1897   case SSEUp:
1898     assert(Lo == SSE && "Unexpected SSEUp classification.");
1899     ResType = GetByteVectorType(RetTy);
1900     break;
1901 
1902     // AMD64-ABI 3.2.3p4: Rule 7. If the class is X87UP, the value is
1903     // returned together with the previous X87 value in %st0.
1904   case X87Up:
1905     // If X87Up is preceded by X87, we don't need to do
1906     // anything. However, in some cases with unions it may not be
1907     // preceded by X87. In such situations we follow gcc and pass the
1908     // extra bits in an SSE reg.
1909     if (Lo != X87) {
1910       HighPart = GetSSETypeAtOffset(CGT.ConvertType(RetTy), 8, RetTy, 8);
1911       if (Lo == NoClass)  // Return HighPart at offset 8 in memory.
1912         return ABIArgInfo::getDirect(HighPart, 8);
1913     }
1914     break;
1915   }
1916 
1917   // If a high part was specified, merge it together with the low part.  It is
1918   // known to pass in the high eightbyte of the result.  We do this by forming a
1919   // first class struct aggregate with the high and low part: {low, high}
1920   if (HighPart)
1921     ResType = GetX86_64ByValArgumentPair(ResType, HighPart, getTargetData());
1922 
1923   return ABIArgInfo::getDirect(ResType);
1924 }
1925 
1926 ABIArgInfo X86_64ABIInfo::classifyArgumentType(
1927   QualType Ty, unsigned freeIntRegs, unsigned &neededInt, unsigned &neededSSE)
1928   const
1929 {
1930   X86_64ABIInfo::Class Lo, Hi;
1931   classify(Ty, 0, Lo, Hi);
1932 
1933   // Check some invariants.
1934   // FIXME: Enforce these by construction.
1935   assert((Hi != Memory || Lo == Memory) && "Invalid memory classification.");
1936   assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp classification.");
1937 
1938   neededInt = 0;
1939   neededSSE = 0;
1940   llvm::Type *ResType = 0;
1941   switch (Lo) {
1942   case NoClass:
1943     if (Hi == NoClass)
1944       return ABIArgInfo::getIgnore();
1945     // If the low part is just padding, it takes no register, leave ResType
1946     // null.
1947     assert((Hi == SSE || Hi == Integer || Hi == X87Up) &&
1948            "Unknown missing lo part");
1949     break;
1950 
1951     // AMD64-ABI 3.2.3p3: Rule 1. If the class is MEMORY, pass the argument
1952     // on the stack.
1953   case Memory:
1954 
1955     // AMD64-ABI 3.2.3p3: Rule 5. If the class is X87, X87UP or
1956     // COMPLEX_X87, it is passed in memory.
1957   case X87:
1958   case ComplexX87:
1959     if (isRecordWithNonTrivialDestructorOrCopyConstructor(Ty))
1960       ++neededInt;
1961     return getIndirectResult(Ty, freeIntRegs);
1962 
1963   case SSEUp:
1964   case X87Up:
1965     llvm_unreachable("Invalid classification for lo word.");
1966 
1967     // AMD64-ABI 3.2.3p3: Rule 2. If the class is INTEGER, the next
1968     // available register of the sequence %rdi, %rsi, %rdx, %rcx, %r8
1969     // and %r9 is used.
1970   case Integer:
1971     ++neededInt;
1972 
1973     // Pick an 8-byte type based on the preferred type.
1974     ResType = GetINTEGERTypeAtOffset(CGT.ConvertType(Ty), 0, Ty, 0);
1975 
1976     // If we have a sign or zero extended integer, make sure to return Extend
1977     // so that the parameter gets the right LLVM IR attributes.
1978     if (Hi == NoClass && isa<llvm::IntegerType>(ResType)) {
1979       // Treat an enum type as its underlying type.
1980       if (const EnumType *EnumTy = Ty->getAs<EnumType>())
1981         Ty = EnumTy->getDecl()->getIntegerType();
1982 
1983       if (Ty->isIntegralOrEnumerationType() &&
1984           Ty->isPromotableIntegerType())
1985         return ABIArgInfo::getExtend();
1986     }
1987 
1988     break;
1989 
1990     // AMD64-ABI 3.2.3p3: Rule 3. If the class is SSE, the next
1991     // available SSE register is used, the registers are taken in the
1992     // order from %xmm0 to %xmm7.
1993   case SSE: {
1994     llvm::Type *IRType = CGT.ConvertType(Ty);
1995     ResType = GetSSETypeAtOffset(IRType, 0, Ty, 0);
1996     ++neededSSE;
1997     break;
1998   }
1999   }
2000 
2001   llvm::Type *HighPart = 0;
2002   switch (Hi) {
2003     // Memory was handled previously, ComplexX87 and X87 should
2004     // never occur as hi classes, and X87Up must be preceded by X87,
2005     // which is passed in memory.
2006   case Memory:
2007   case X87:
2008   case ComplexX87:
2009     llvm_unreachable("Invalid classification for hi word.");
2010 
2011   case NoClass: break;
2012 
2013   case Integer:
2014     ++neededInt;
2015     // Pick an 8-byte type based on the preferred type.
2016     HighPart = GetINTEGERTypeAtOffset(CGT.ConvertType(Ty), 8, Ty, 8);
2017 
2018     if (Lo == NoClass)  // Pass HighPart at offset 8 in memory.
2019       return ABIArgInfo::getDirect(HighPart, 8);
2020     break;
2021 
2022     // X87Up generally doesn't occur here (long double is passed in
2023     // memory), except in situations involving unions.
2024   case X87Up:
2025   case SSE:
2026     HighPart = GetSSETypeAtOffset(CGT.ConvertType(Ty), 8, Ty, 8);
2027 
2028     if (Lo == NoClass)  // Pass HighPart at offset 8 in memory.
2029       return ABIArgInfo::getDirect(HighPart, 8);
2030 
2031     ++neededSSE;
2032     break;
2033 
2034     // AMD64-ABI 3.2.3p3: Rule 4. If the class is SSEUP, the
2035     // eightbyte is passed in the upper half of the last used SSE
2036     // register.  This only happens when 128-bit vectors are passed.
2037   case SSEUp:
2038     assert(Lo == SSE && "Unexpected SSEUp classification");
2039     ResType = GetByteVectorType(Ty);
2040     break;
2041   }
2042 
2043   // If a high part was specified, merge it together with the low part.  It is
2044   // known to pass in the high eightbyte of the result.  We do this by forming a
2045   // first class struct aggregate with the high and low part: {low, high}
2046   if (HighPart)
2047     ResType = GetX86_64ByValArgumentPair(ResType, HighPart, getTargetData());
2048 
2049   return ABIArgInfo::getDirect(ResType);
2050 }
2051 
2052 void X86_64ABIInfo::computeInfo(CGFunctionInfo &FI) const {
2053 
2054   FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
2055 
2056   // Keep track of the number of assigned registers.
2057   unsigned freeIntRegs = 6, freeSSERegs = 8;
2058 
2059   // If the return value is indirect, then the hidden argument is consuming one
2060   // integer register.
2061   if (FI.getReturnInfo().isIndirect())
2062     --freeIntRegs;
2063 
2064   // AMD64-ABI 3.2.3p3: Once arguments are classified, the registers
2065   // get assigned (in left-to-right order) for passing as follows...
2066   for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
2067        it != ie; ++it) {
2068     unsigned neededInt, neededSSE;
2069     it->info = classifyArgumentType(it->type, freeIntRegs, neededInt,
2070                                     neededSSE);
2071 
2072     // AMD64-ABI 3.2.3p3: If there are no registers available for any
2073     // eightbyte of an argument, the whole argument is passed on the
2074     // stack. If registers have already been assigned for some
2075     // eightbytes of such an argument, the assignments get reverted.
2076     if (freeIntRegs >= neededInt && freeSSERegs >= neededSSE) {
2077       freeIntRegs -= neededInt;
2078       freeSSERegs -= neededSSE;
2079     } else {
2080       it->info = getIndirectResult(it->type, freeIntRegs);
2081     }
2082   }
2083 }
2084 
2085 static llvm::Value *EmitVAArgFromMemory(llvm::Value *VAListAddr,
2086                                         QualType Ty,
2087                                         CodeGenFunction &CGF) {
2088   llvm::Value *overflow_arg_area_p =
2089     CGF.Builder.CreateStructGEP(VAListAddr, 2, "overflow_arg_area_p");
2090   llvm::Value *overflow_arg_area =
2091     CGF.Builder.CreateLoad(overflow_arg_area_p, "overflow_arg_area");
2092 
2093   // AMD64-ABI 3.5.7p5: Step 7. Align l->overflow_arg_area upwards to a 16
2094   // byte boundary if alignment needed by type exceeds 8 byte boundary.
2095   // It isn't stated explicitly in the standard, but in practice we use
2096   // alignment greater than 16 where necessary.
2097   uint64_t Align = CGF.getContext().getTypeAlign(Ty) / 8;
2098   if (Align > 8) {
2099     // overflow_arg_area = (overflow_arg_area + align - 1) & -align;
2100     llvm::Value *Offset =
2101       llvm::ConstantInt::get(CGF.Int64Ty, Align - 1);
2102     overflow_arg_area = CGF.Builder.CreateGEP(overflow_arg_area, Offset);
2103     llvm::Value *AsInt = CGF.Builder.CreatePtrToInt(overflow_arg_area,
2104                                                     CGF.Int64Ty);
2105     llvm::Value *Mask = llvm::ConstantInt::get(CGF.Int64Ty, -(uint64_t)Align);
2106     overflow_arg_area =
2107       CGF.Builder.CreateIntToPtr(CGF.Builder.CreateAnd(AsInt, Mask),
2108                                  overflow_arg_area->getType(),
2109                                  "overflow_arg_area.align");
2110   }
2111 
2112   // AMD64-ABI 3.5.7p5: Step 8. Fetch type from l->overflow_arg_area.
2113   llvm::Type *LTy = CGF.ConvertTypeForMem(Ty);
2114   llvm::Value *Res =
2115     CGF.Builder.CreateBitCast(overflow_arg_area,
2116                               llvm::PointerType::getUnqual(LTy));
2117 
2118   // AMD64-ABI 3.5.7p5: Step 9. Set l->overflow_arg_area to:
2119   // l->overflow_arg_area + sizeof(type).
2120   // AMD64-ABI 3.5.7p5: Step 10. Align l->overflow_arg_area upwards to
2121   // an 8 byte boundary.
2122 
2123   uint64_t SizeInBytes = (CGF.getContext().getTypeSize(Ty) + 7) / 8;
2124   llvm::Value *Offset =
2125       llvm::ConstantInt::get(CGF.Int32Ty, (SizeInBytes + 7)  & ~7);
2126   overflow_arg_area = CGF.Builder.CreateGEP(overflow_arg_area, Offset,
2127                                             "overflow_arg_area.next");
2128   CGF.Builder.CreateStore(overflow_arg_area, overflow_arg_area_p);
2129 
2130   // AMD64-ABI 3.5.7p5: Step 11. Return the fetched type.
2131   return Res;
2132 }
2133 
2134 llvm::Value *X86_64ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
2135                                       CodeGenFunction &CGF) const {
2136   // Assume that va_list type is correct; should be pointer to LLVM type:
2137   // struct {
2138   //   i32 gp_offset;
2139   //   i32 fp_offset;
2140   //   i8* overflow_arg_area;
2141   //   i8* reg_save_area;
2142   // };
2143   unsigned neededInt, neededSSE;
2144 
2145   Ty = CGF.getContext().getCanonicalType(Ty);
2146   ABIArgInfo AI = classifyArgumentType(Ty, 0, neededInt, neededSSE);
2147 
2148   // AMD64-ABI 3.5.7p5: Step 1. Determine whether type may be passed
2149   // in the registers. If not go to step 7.
2150   if (!neededInt && !neededSSE)
2151     return EmitVAArgFromMemory(VAListAddr, Ty, CGF);
2152 
2153   // AMD64-ABI 3.5.7p5: Step 2. Compute num_gp to hold the number of
2154   // general purpose registers needed to pass type and num_fp to hold
2155   // the number of floating point registers needed.
2156 
2157   // AMD64-ABI 3.5.7p5: Step 3. Verify whether arguments fit into
2158   // registers. In the case: l->gp_offset > 48 - num_gp * 8 or
2159   // l->fp_offset > 304 - num_fp * 16 go to step 7.
2160   //
2161   // NOTE: 304 is a typo, there are (6 * 8 + 8 * 16) = 176 bytes of
2162   // register save space).
2163 
2164   llvm::Value *InRegs = 0;
2165   llvm::Value *gp_offset_p = 0, *gp_offset = 0;
2166   llvm::Value *fp_offset_p = 0, *fp_offset = 0;
2167   if (neededInt) {
2168     gp_offset_p = CGF.Builder.CreateStructGEP(VAListAddr, 0, "gp_offset_p");
2169     gp_offset = CGF.Builder.CreateLoad(gp_offset_p, "gp_offset");
2170     InRegs = llvm::ConstantInt::get(CGF.Int32Ty, 48 - neededInt * 8);
2171     InRegs = CGF.Builder.CreateICmpULE(gp_offset, InRegs, "fits_in_gp");
2172   }
2173 
2174   if (neededSSE) {
2175     fp_offset_p = CGF.Builder.CreateStructGEP(VAListAddr, 1, "fp_offset_p");
2176     fp_offset = CGF.Builder.CreateLoad(fp_offset_p, "fp_offset");
2177     llvm::Value *FitsInFP =
2178       llvm::ConstantInt::get(CGF.Int32Ty, 176 - neededSSE * 16);
2179     FitsInFP = CGF.Builder.CreateICmpULE(fp_offset, FitsInFP, "fits_in_fp");
2180     InRegs = InRegs ? CGF.Builder.CreateAnd(InRegs, FitsInFP) : FitsInFP;
2181   }
2182 
2183   llvm::BasicBlock *InRegBlock = CGF.createBasicBlock("vaarg.in_reg");
2184   llvm::BasicBlock *InMemBlock = CGF.createBasicBlock("vaarg.in_mem");
2185   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("vaarg.end");
2186   CGF.Builder.CreateCondBr(InRegs, InRegBlock, InMemBlock);
2187 
2188   // Emit code to load the value if it was passed in registers.
2189 
2190   CGF.EmitBlock(InRegBlock);
2191 
2192   // AMD64-ABI 3.5.7p5: Step 4. Fetch type from l->reg_save_area with
2193   // an offset of l->gp_offset and/or l->fp_offset. This may require
2194   // copying to a temporary location in case the parameter is passed
2195   // in different register classes or requires an alignment greater
2196   // than 8 for general purpose registers and 16 for XMM registers.
2197   //
2198   // FIXME: This really results in shameful code when we end up needing to
2199   // collect arguments from different places; often what should result in a
2200   // simple assembling of a structure from scattered addresses has many more
2201   // loads than necessary. Can we clean this up?
2202   llvm::Type *LTy = CGF.ConvertTypeForMem(Ty);
2203   llvm::Value *RegAddr =
2204     CGF.Builder.CreateLoad(CGF.Builder.CreateStructGEP(VAListAddr, 3),
2205                            "reg_save_area");
2206   if (neededInt && neededSSE) {
2207     // FIXME: Cleanup.
2208     assert(AI.isDirect() && "Unexpected ABI info for mixed regs");
2209     llvm::StructType *ST = cast<llvm::StructType>(AI.getCoerceToType());
2210     llvm::Value *Tmp = CGF.CreateTempAlloca(ST);
2211     assert(ST->getNumElements() == 2 && "Unexpected ABI info for mixed regs");
2212     llvm::Type *TyLo = ST->getElementType(0);
2213     llvm::Type *TyHi = ST->getElementType(1);
2214     assert((TyLo->isFPOrFPVectorTy() ^ TyHi->isFPOrFPVectorTy()) &&
2215            "Unexpected ABI info for mixed regs");
2216     llvm::Type *PTyLo = llvm::PointerType::getUnqual(TyLo);
2217     llvm::Type *PTyHi = llvm::PointerType::getUnqual(TyHi);
2218     llvm::Value *GPAddr = CGF.Builder.CreateGEP(RegAddr, gp_offset);
2219     llvm::Value *FPAddr = CGF.Builder.CreateGEP(RegAddr, fp_offset);
2220     llvm::Value *RegLoAddr = TyLo->isFloatingPointTy() ? FPAddr : GPAddr;
2221     llvm::Value *RegHiAddr = TyLo->isFloatingPointTy() ? GPAddr : FPAddr;
2222     llvm::Value *V =
2223       CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegLoAddr, PTyLo));
2224     CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 0));
2225     V = CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegHiAddr, PTyHi));
2226     CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 1));
2227 
2228     RegAddr = CGF.Builder.CreateBitCast(Tmp,
2229                                         llvm::PointerType::getUnqual(LTy));
2230   } else if (neededInt) {
2231     RegAddr = CGF.Builder.CreateGEP(RegAddr, gp_offset);
2232     RegAddr = CGF.Builder.CreateBitCast(RegAddr,
2233                                         llvm::PointerType::getUnqual(LTy));
2234   } else if (neededSSE == 1) {
2235     RegAddr = CGF.Builder.CreateGEP(RegAddr, fp_offset);
2236     RegAddr = CGF.Builder.CreateBitCast(RegAddr,
2237                                         llvm::PointerType::getUnqual(LTy));
2238   } else {
2239     assert(neededSSE == 2 && "Invalid number of needed registers!");
2240     // SSE registers are spaced 16 bytes apart in the register save
2241     // area, we need to collect the two eightbytes together.
2242     llvm::Value *RegAddrLo = CGF.Builder.CreateGEP(RegAddr, fp_offset);
2243     llvm::Value *RegAddrHi = CGF.Builder.CreateConstGEP1_32(RegAddrLo, 16);
2244     llvm::Type *DoubleTy = CGF.DoubleTy;
2245     llvm::Type *DblPtrTy =
2246       llvm::PointerType::getUnqual(DoubleTy);
2247     llvm::StructType *ST = llvm::StructType::get(DoubleTy,
2248                                                        DoubleTy, NULL);
2249     llvm::Value *V, *Tmp = CGF.CreateTempAlloca(ST);
2250     V = CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegAddrLo,
2251                                                          DblPtrTy));
2252     CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 0));
2253     V = CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegAddrHi,
2254                                                          DblPtrTy));
2255     CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 1));
2256     RegAddr = CGF.Builder.CreateBitCast(Tmp,
2257                                         llvm::PointerType::getUnqual(LTy));
2258   }
2259 
2260   // AMD64-ABI 3.5.7p5: Step 5. Set:
2261   // l->gp_offset = l->gp_offset + num_gp * 8
2262   // l->fp_offset = l->fp_offset + num_fp * 16.
2263   if (neededInt) {
2264     llvm::Value *Offset = llvm::ConstantInt::get(CGF.Int32Ty, neededInt * 8);
2265     CGF.Builder.CreateStore(CGF.Builder.CreateAdd(gp_offset, Offset),
2266                             gp_offset_p);
2267   }
2268   if (neededSSE) {
2269     llvm::Value *Offset = llvm::ConstantInt::get(CGF.Int32Ty, neededSSE * 16);
2270     CGF.Builder.CreateStore(CGF.Builder.CreateAdd(fp_offset, Offset),
2271                             fp_offset_p);
2272   }
2273   CGF.EmitBranch(ContBlock);
2274 
2275   // Emit code to load the value if it was passed in memory.
2276 
2277   CGF.EmitBlock(InMemBlock);
2278   llvm::Value *MemAddr = EmitVAArgFromMemory(VAListAddr, Ty, CGF);
2279 
2280   // Return the appropriate result.
2281 
2282   CGF.EmitBlock(ContBlock);
2283   llvm::PHINode *ResAddr = CGF.Builder.CreatePHI(RegAddr->getType(), 2,
2284                                                  "vaarg.addr");
2285   ResAddr->addIncoming(RegAddr, InRegBlock);
2286   ResAddr->addIncoming(MemAddr, InMemBlock);
2287   return ResAddr;
2288 }
2289 
2290 ABIArgInfo WinX86_64ABIInfo::classify(QualType Ty) const {
2291 
2292   if (Ty->isVoidType())
2293     return ABIArgInfo::getIgnore();
2294 
2295   if (const EnumType *EnumTy = Ty->getAs<EnumType>())
2296     Ty = EnumTy->getDecl()->getIntegerType();
2297 
2298   uint64_t Size = getContext().getTypeSize(Ty);
2299 
2300   if (const RecordType *RT = Ty->getAs<RecordType>()) {
2301     if (hasNonTrivialDestructorOrCopyConstructor(RT) ||
2302         RT->getDecl()->hasFlexibleArrayMember())
2303       return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
2304 
2305     // FIXME: mingw-w64-gcc emits 128-bit struct as i128
2306     if (Size == 128 &&
2307         getContext().getTargetInfo().getTriple().getOS()
2308           == llvm::Triple::MinGW32)
2309       return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),
2310                                                           Size));
2311 
2312     // MS x64 ABI requirement: "Any argument that doesn't fit in 8 bytes, or is
2313     // not 1, 2, 4, or 8 bytes, must be passed by reference."
2314     if (Size <= 64 &&
2315         (Size & (Size - 1)) == 0)
2316       return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),
2317                                                           Size));
2318 
2319     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
2320   }
2321 
2322   if (Ty->isPromotableIntegerType())
2323     return ABIArgInfo::getExtend();
2324 
2325   return ABIArgInfo::getDirect();
2326 }
2327 
2328 void WinX86_64ABIInfo::computeInfo(CGFunctionInfo &FI) const {
2329 
2330   QualType RetTy = FI.getReturnType();
2331   FI.getReturnInfo() = classify(RetTy);
2332 
2333   for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
2334        it != ie; ++it)
2335     it->info = classify(it->type);
2336 }
2337 
2338 llvm::Value *WinX86_64ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
2339                                       CodeGenFunction &CGF) const {
2340   llvm::Type *BPP = CGF.Int8PtrPtrTy;
2341 
2342   CGBuilderTy &Builder = CGF.Builder;
2343   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP,
2344                                                        "ap");
2345   llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
2346   llvm::Type *PTy =
2347     llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
2348   llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy);
2349 
2350   uint64_t Offset =
2351     llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, 8);
2352   llvm::Value *NextAddr =
2353     Builder.CreateGEP(Addr, llvm::ConstantInt::get(CGF.Int32Ty, Offset),
2354                       "ap.next");
2355   Builder.CreateStore(NextAddr, VAListAddrAsBPP);
2356 
2357   return AddrTyped;
2358 }
2359 
2360 // PowerPC-32
2361 
2362 namespace {
2363 class PPC32TargetCodeGenInfo : public DefaultTargetCodeGenInfo {
2364 public:
2365   PPC32TargetCodeGenInfo(CodeGenTypes &CGT) : DefaultTargetCodeGenInfo(CGT) {}
2366 
2367   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const {
2368     // This is recovered from gcc output.
2369     return 1; // r1 is the dedicated stack pointer
2370   }
2371 
2372   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
2373                                llvm::Value *Address) const;
2374 };
2375 
2376 }
2377 
2378 bool
2379 PPC32TargetCodeGenInfo::initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
2380                                                 llvm::Value *Address) const {
2381   // This is calculated from the LLVM and GCC tables and verified
2382   // against gcc output.  AFAIK all ABIs use the same encoding.
2383 
2384   CodeGen::CGBuilderTy &Builder = CGF.Builder;
2385 
2386   llvm::IntegerType *i8 = CGF.Int8Ty;
2387   llvm::Value *Four8 = llvm::ConstantInt::get(i8, 4);
2388   llvm::Value *Eight8 = llvm::ConstantInt::get(i8, 8);
2389   llvm::Value *Sixteen8 = llvm::ConstantInt::get(i8, 16);
2390 
2391   // 0-31: r0-31, the 4-byte general-purpose registers
2392   AssignToArrayRange(Builder, Address, Four8, 0, 31);
2393 
2394   // 32-63: fp0-31, the 8-byte floating-point registers
2395   AssignToArrayRange(Builder, Address, Eight8, 32, 63);
2396 
2397   // 64-76 are various 4-byte special-purpose registers:
2398   // 64: mq
2399   // 65: lr
2400   // 66: ctr
2401   // 67: ap
2402   // 68-75 cr0-7
2403   // 76: xer
2404   AssignToArrayRange(Builder, Address, Four8, 64, 76);
2405 
2406   // 77-108: v0-31, the 16-byte vector registers
2407   AssignToArrayRange(Builder, Address, Sixteen8, 77, 108);
2408 
2409   // 109: vrsave
2410   // 110: vscr
2411   // 111: spe_acc
2412   // 112: spefscr
2413   // 113: sfp
2414   AssignToArrayRange(Builder, Address, Four8, 109, 113);
2415 
2416   return false;
2417 }
2418 
2419 // PowerPC-64
2420 
2421 namespace {
2422 class PPC64TargetCodeGenInfo : public DefaultTargetCodeGenInfo {
2423 public:
2424   PPC64TargetCodeGenInfo(CodeGenTypes &CGT) : DefaultTargetCodeGenInfo(CGT) {}
2425 
2426   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const {
2427     // This is recovered from gcc output.
2428     return 1; // r1 is the dedicated stack pointer
2429   }
2430 
2431   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
2432                                llvm::Value *Address) const;
2433 };
2434 
2435 }
2436 
2437 bool
2438 PPC64TargetCodeGenInfo::initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
2439                                                 llvm::Value *Address) const {
2440   // This is calculated from the LLVM and GCC tables and verified
2441   // against gcc output.  AFAIK all ABIs use the same encoding.
2442 
2443   CodeGen::CGBuilderTy &Builder = CGF.Builder;
2444 
2445   llvm::IntegerType *i8 = CGF.Int8Ty;
2446   llvm::Value *Four8 = llvm::ConstantInt::get(i8, 4);
2447   llvm::Value *Eight8 = llvm::ConstantInt::get(i8, 8);
2448   llvm::Value *Sixteen8 = llvm::ConstantInt::get(i8, 16);
2449 
2450   // 0-31: r0-31, the 8-byte general-purpose registers
2451   AssignToArrayRange(Builder, Address, Eight8, 0, 31);
2452 
2453   // 32-63: fp0-31, the 8-byte floating-point registers
2454   AssignToArrayRange(Builder, Address, Eight8, 32, 63);
2455 
2456   // 64-76 are various 4-byte special-purpose registers:
2457   // 64: mq
2458   // 65: lr
2459   // 66: ctr
2460   // 67: ap
2461   // 68-75 cr0-7
2462   // 76: xer
2463   AssignToArrayRange(Builder, Address, Four8, 64, 76);
2464 
2465   // 77-108: v0-31, the 16-byte vector registers
2466   AssignToArrayRange(Builder, Address, Sixteen8, 77, 108);
2467 
2468   // 109: vrsave
2469   // 110: vscr
2470   // 111: spe_acc
2471   // 112: spefscr
2472   // 113: sfp
2473   AssignToArrayRange(Builder, Address, Four8, 109, 113);
2474 
2475   return false;
2476 }
2477 
2478 //===----------------------------------------------------------------------===//
2479 // ARM ABI Implementation
2480 //===----------------------------------------------------------------------===//
2481 
2482 namespace {
2483 
2484 class ARMABIInfo : public ABIInfo {
2485 public:
2486   enum ABIKind {
2487     APCS = 0,
2488     AAPCS = 1,
2489     AAPCS_VFP
2490   };
2491 
2492 private:
2493   ABIKind Kind;
2494 
2495 public:
2496   ARMABIInfo(CodeGenTypes &CGT, ABIKind _Kind) : ABIInfo(CGT), Kind(_Kind) {}
2497 
2498   bool isEABI() const {
2499     StringRef Env =
2500       getContext().getTargetInfo().getTriple().getEnvironmentName();
2501     return (Env == "gnueabi" || Env == "eabi" || Env == "androideabi");
2502   }
2503 
2504 private:
2505   ABIKind getABIKind() const { return Kind; }
2506 
2507   ABIArgInfo classifyReturnType(QualType RetTy) const;
2508   ABIArgInfo classifyArgumentType(QualType RetTy) const;
2509 
2510   virtual void computeInfo(CGFunctionInfo &FI) const;
2511 
2512   virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
2513                                  CodeGenFunction &CGF) const;
2514 };
2515 
2516 class ARMTargetCodeGenInfo : public TargetCodeGenInfo {
2517 public:
2518   ARMTargetCodeGenInfo(CodeGenTypes &CGT, ARMABIInfo::ABIKind K)
2519     :TargetCodeGenInfo(new ARMABIInfo(CGT, K)) {}
2520 
2521   const ARMABIInfo &getABIInfo() const {
2522     return static_cast<const ARMABIInfo&>(TargetCodeGenInfo::getABIInfo());
2523   }
2524 
2525   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const {
2526     return 13;
2527   }
2528 
2529   StringRef getARCRetainAutoreleasedReturnValueMarker() const {
2530     return "mov\tr7, r7\t\t@ marker for objc_retainAutoreleaseReturnValue";
2531   }
2532 
2533   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
2534                                llvm::Value *Address) const {
2535     llvm::Value *Four8 = llvm::ConstantInt::get(CGF.Int8Ty, 4);
2536 
2537     // 0-15 are the 16 integer registers.
2538     AssignToArrayRange(CGF.Builder, Address, Four8, 0, 15);
2539     return false;
2540   }
2541 
2542   unsigned getSizeOfUnwindException() const {
2543     if (getABIInfo().isEABI()) return 88;
2544     return TargetCodeGenInfo::getSizeOfUnwindException();
2545   }
2546 };
2547 
2548 }
2549 
2550 void ARMABIInfo::computeInfo(CGFunctionInfo &FI) const {
2551   FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
2552   for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
2553        it != ie; ++it)
2554     it->info = classifyArgumentType(it->type);
2555 
2556   // Always honor user-specified calling convention.
2557   if (FI.getCallingConvention() != llvm::CallingConv::C)
2558     return;
2559 
2560   // Calling convention as default by an ABI.
2561   llvm::CallingConv::ID DefaultCC;
2562   if (isEABI())
2563     DefaultCC = llvm::CallingConv::ARM_AAPCS;
2564   else
2565     DefaultCC = llvm::CallingConv::ARM_APCS;
2566 
2567   // If user did not ask for specific calling convention explicitly (e.g. via
2568   // pcs attribute), set effective calling convention if it's different than ABI
2569   // default.
2570   switch (getABIKind()) {
2571   case APCS:
2572     if (DefaultCC != llvm::CallingConv::ARM_APCS)
2573       FI.setEffectiveCallingConvention(llvm::CallingConv::ARM_APCS);
2574     break;
2575   case AAPCS:
2576     if (DefaultCC != llvm::CallingConv::ARM_AAPCS)
2577       FI.setEffectiveCallingConvention(llvm::CallingConv::ARM_AAPCS);
2578     break;
2579   case AAPCS_VFP:
2580     if (DefaultCC != llvm::CallingConv::ARM_AAPCS_VFP)
2581       FI.setEffectiveCallingConvention(llvm::CallingConv::ARM_AAPCS_VFP);
2582     break;
2583   }
2584 }
2585 
2586 /// isHomogeneousAggregate - Return true if a type is an AAPCS-VFP homogeneous
2587 /// aggregate.  If HAMembers is non-null, the number of base elements
2588 /// contained in the type is returned through it; this is used for the
2589 /// recursive calls that check aggregate component types.
2590 static bool isHomogeneousAggregate(QualType Ty, const Type *&Base,
2591                                    ASTContext &Context,
2592                                    uint64_t *HAMembers = 0) {
2593   uint64_t Members = 0;
2594   if (const ConstantArrayType *AT = Context.getAsConstantArrayType(Ty)) {
2595     if (!isHomogeneousAggregate(AT->getElementType(), Base, Context, &Members))
2596       return false;
2597     Members *= AT->getSize().getZExtValue();
2598   } else if (const RecordType *RT = Ty->getAs<RecordType>()) {
2599     const RecordDecl *RD = RT->getDecl();
2600     if (RD->hasFlexibleArrayMember())
2601       return false;
2602 
2603     Members = 0;
2604     for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
2605          i != e; ++i) {
2606       const FieldDecl *FD = *i;
2607       uint64_t FldMembers;
2608       if (!isHomogeneousAggregate(FD->getType(), Base, Context, &FldMembers))
2609         return false;
2610 
2611       Members = (RD->isUnion() ?
2612                  std::max(Members, FldMembers) : Members + FldMembers);
2613     }
2614   } else {
2615     Members = 1;
2616     if (const ComplexType *CT = Ty->getAs<ComplexType>()) {
2617       Members = 2;
2618       Ty = CT->getElementType();
2619     }
2620 
2621     // Homogeneous aggregates for AAPCS-VFP must have base types of float,
2622     // double, or 64-bit or 128-bit vectors.
2623     if (const BuiltinType *BT = Ty->getAs<BuiltinType>()) {
2624       if (BT->getKind() != BuiltinType::Float &&
2625           BT->getKind() != BuiltinType::Double)
2626         return false;
2627     } else if (const VectorType *VT = Ty->getAs<VectorType>()) {
2628       unsigned VecSize = Context.getTypeSize(VT);
2629       if (VecSize != 64 && VecSize != 128)
2630         return false;
2631     } else {
2632       return false;
2633     }
2634 
2635     // The base type must be the same for all members.  Vector types of the
2636     // same total size are treated as being equivalent here.
2637     const Type *TyPtr = Ty.getTypePtr();
2638     if (!Base)
2639       Base = TyPtr;
2640     if (Base != TyPtr &&
2641         (!Base->isVectorType() || !TyPtr->isVectorType() ||
2642          Context.getTypeSize(Base) != Context.getTypeSize(TyPtr)))
2643       return false;
2644   }
2645 
2646   // Homogeneous Aggregates can have at most 4 members of the base type.
2647   if (HAMembers)
2648     *HAMembers = Members;
2649 
2650   return (Members > 0 && Members <= 4);
2651 }
2652 
2653 ABIArgInfo ARMABIInfo::classifyArgumentType(QualType Ty) const {
2654   if (!isAggregateTypeForABI(Ty)) {
2655     // Treat an enum type as its underlying type.
2656     if (const EnumType *EnumTy = Ty->getAs<EnumType>())
2657       Ty = EnumTy->getDecl()->getIntegerType();
2658 
2659     return (Ty->isPromotableIntegerType() ?
2660             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
2661   }
2662 
2663   // Ignore empty records.
2664   if (isEmptyRecord(getContext(), Ty, true))
2665     return ABIArgInfo::getIgnore();
2666 
2667   // Structures with either a non-trivial destructor or a non-trivial
2668   // copy constructor are always indirect.
2669   if (isRecordWithNonTrivialDestructorOrCopyConstructor(Ty))
2670     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
2671 
2672   if (getABIKind() == ARMABIInfo::AAPCS_VFP) {
2673     // Homogeneous Aggregates need to be expanded.
2674     const Type *Base = 0;
2675     if (isHomogeneousAggregate(Ty, Base, getContext())) {
2676       assert(Base && "Base class should be set for homogeneous aggregate");
2677       return ABIArgInfo::getExpand();
2678     }
2679   }
2680 
2681   // Otherwise, pass by coercing to a structure of the appropriate size.
2682   //
2683   // FIXME: This is kind of nasty... but there isn't much choice because the ARM
2684   // backend doesn't support byval.
2685   // FIXME: This doesn't handle alignment > 64 bits.
2686   llvm::Type* ElemTy;
2687   unsigned SizeRegs;
2688   if (getContext().getTypeAlign(Ty) > 32) {
2689     ElemTy = llvm::Type::getInt64Ty(getVMContext());
2690     SizeRegs = (getContext().getTypeSize(Ty) + 63) / 64;
2691   } else {
2692     ElemTy = llvm::Type::getInt32Ty(getVMContext());
2693     SizeRegs = (getContext().getTypeSize(Ty) + 31) / 32;
2694   }
2695 
2696   llvm::Type *STy =
2697     llvm::StructType::get(llvm::ArrayType::get(ElemTy, SizeRegs), NULL);
2698   return ABIArgInfo::getDirect(STy);
2699 }
2700 
2701 static bool isIntegerLikeType(QualType Ty, ASTContext &Context,
2702                               llvm::LLVMContext &VMContext) {
2703   // APCS, C Language Calling Conventions, Non-Simple Return Values: A structure
2704   // is called integer-like if its size is less than or equal to one word, and
2705   // the offset of each of its addressable sub-fields is zero.
2706 
2707   uint64_t Size = Context.getTypeSize(Ty);
2708 
2709   // Check that the type fits in a word.
2710   if (Size > 32)
2711     return false;
2712 
2713   // FIXME: Handle vector types!
2714   if (Ty->isVectorType())
2715     return false;
2716 
2717   // Float types are never treated as "integer like".
2718   if (Ty->isRealFloatingType())
2719     return false;
2720 
2721   // If this is a builtin or pointer type then it is ok.
2722   if (Ty->getAs<BuiltinType>() || Ty->isPointerType())
2723     return true;
2724 
2725   // Small complex integer types are "integer like".
2726   if (const ComplexType *CT = Ty->getAs<ComplexType>())
2727     return isIntegerLikeType(CT->getElementType(), Context, VMContext);
2728 
2729   // Single element and zero sized arrays should be allowed, by the definition
2730   // above, but they are not.
2731 
2732   // Otherwise, it must be a record type.
2733   const RecordType *RT = Ty->getAs<RecordType>();
2734   if (!RT) return false;
2735 
2736   // Ignore records with flexible arrays.
2737   const RecordDecl *RD = RT->getDecl();
2738   if (RD->hasFlexibleArrayMember())
2739     return false;
2740 
2741   // Check that all sub-fields are at offset 0, and are themselves "integer
2742   // like".
2743   const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
2744 
2745   bool HadField = false;
2746   unsigned idx = 0;
2747   for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
2748        i != e; ++i, ++idx) {
2749     const FieldDecl *FD = *i;
2750 
2751     // Bit-fields are not addressable, we only need to verify they are "integer
2752     // like". We still have to disallow a subsequent non-bitfield, for example:
2753     //   struct { int : 0; int x }
2754     // is non-integer like according to gcc.
2755     if (FD->isBitField()) {
2756       if (!RD->isUnion())
2757         HadField = true;
2758 
2759       if (!isIntegerLikeType(FD->getType(), Context, VMContext))
2760         return false;
2761 
2762       continue;
2763     }
2764 
2765     // Check if this field is at offset 0.
2766     if (Layout.getFieldOffset(idx) != 0)
2767       return false;
2768 
2769     if (!isIntegerLikeType(FD->getType(), Context, VMContext))
2770       return false;
2771 
2772     // Only allow at most one field in a structure. This doesn't match the
2773     // wording above, but follows gcc in situations with a field following an
2774     // empty structure.
2775     if (!RD->isUnion()) {
2776       if (HadField)
2777         return false;
2778 
2779       HadField = true;
2780     }
2781   }
2782 
2783   return true;
2784 }
2785 
2786 ABIArgInfo ARMABIInfo::classifyReturnType(QualType RetTy) const {
2787   if (RetTy->isVoidType())
2788     return ABIArgInfo::getIgnore();
2789 
2790   // Large vector types should be returned via memory.
2791   if (RetTy->isVectorType() && getContext().getTypeSize(RetTy) > 128)
2792     return ABIArgInfo::getIndirect(0);
2793 
2794   if (!isAggregateTypeForABI(RetTy)) {
2795     // Treat an enum type as its underlying type.
2796     if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
2797       RetTy = EnumTy->getDecl()->getIntegerType();
2798 
2799     return (RetTy->isPromotableIntegerType() ?
2800             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
2801   }
2802 
2803   // Structures with either a non-trivial destructor or a non-trivial
2804   // copy constructor are always indirect.
2805   if (isRecordWithNonTrivialDestructorOrCopyConstructor(RetTy))
2806     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
2807 
2808   // Are we following APCS?
2809   if (getABIKind() == APCS) {
2810     if (isEmptyRecord(getContext(), RetTy, false))
2811       return ABIArgInfo::getIgnore();
2812 
2813     // Complex types are all returned as packed integers.
2814     //
2815     // FIXME: Consider using 2 x vector types if the back end handles them
2816     // correctly.
2817     if (RetTy->isAnyComplexType())
2818       return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(),
2819                                               getContext().getTypeSize(RetTy)));
2820 
2821     // Integer like structures are returned in r0.
2822     if (isIntegerLikeType(RetTy, getContext(), getVMContext())) {
2823       // Return in the smallest viable integer type.
2824       uint64_t Size = getContext().getTypeSize(RetTy);
2825       if (Size <= 8)
2826         return ABIArgInfo::getDirect(llvm::Type::getInt8Ty(getVMContext()));
2827       if (Size <= 16)
2828         return ABIArgInfo::getDirect(llvm::Type::getInt16Ty(getVMContext()));
2829       return ABIArgInfo::getDirect(llvm::Type::getInt32Ty(getVMContext()));
2830     }
2831 
2832     // Otherwise return in memory.
2833     return ABIArgInfo::getIndirect(0);
2834   }
2835 
2836   // Otherwise this is an AAPCS variant.
2837 
2838   if (isEmptyRecord(getContext(), RetTy, true))
2839     return ABIArgInfo::getIgnore();
2840 
2841   // Check for homogeneous aggregates with AAPCS-VFP.
2842   if (getABIKind() == AAPCS_VFP) {
2843     const Type *Base = 0;
2844     if (isHomogeneousAggregate(RetTy, Base, getContext())) {
2845       assert(Base && "Base class should be set for homogeneous aggregate");
2846       // Homogeneous Aggregates are returned directly.
2847       return ABIArgInfo::getDirect();
2848     }
2849   }
2850 
2851   // Aggregates <= 4 bytes are returned in r0; other aggregates
2852   // are returned indirectly.
2853   uint64_t Size = getContext().getTypeSize(RetTy);
2854   if (Size <= 32) {
2855     // Return in the smallest viable integer type.
2856     if (Size <= 8)
2857       return ABIArgInfo::getDirect(llvm::Type::getInt8Ty(getVMContext()));
2858     if (Size <= 16)
2859       return ABIArgInfo::getDirect(llvm::Type::getInt16Ty(getVMContext()));
2860     return ABIArgInfo::getDirect(llvm::Type::getInt32Ty(getVMContext()));
2861   }
2862 
2863   return ABIArgInfo::getIndirect(0);
2864 }
2865 
2866 llvm::Value *ARMABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
2867                                    CodeGenFunction &CGF) const {
2868   llvm::Type *BP = CGF.Int8PtrTy;
2869   llvm::Type *BPP = CGF.Int8PtrPtrTy;
2870 
2871   CGBuilderTy &Builder = CGF.Builder;
2872   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP, "ap");
2873   llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
2874   // Handle address alignment for type alignment > 32 bits
2875   uint64_t TyAlign = CGF.getContext().getTypeAlign(Ty) / 8;
2876   if (TyAlign > 4) {
2877     assert((TyAlign & (TyAlign - 1)) == 0 &&
2878            "Alignment is not power of 2!");
2879     llvm::Value *AddrAsInt = Builder.CreatePtrToInt(Addr, CGF.Int32Ty);
2880     AddrAsInt = Builder.CreateAdd(AddrAsInt, Builder.getInt32(TyAlign - 1));
2881     AddrAsInt = Builder.CreateAnd(AddrAsInt, Builder.getInt32(~(TyAlign - 1)));
2882     Addr = Builder.CreateIntToPtr(AddrAsInt, BP);
2883   }
2884   llvm::Type *PTy =
2885     llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
2886   llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy);
2887 
2888   uint64_t Offset =
2889     llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, 4);
2890   llvm::Value *NextAddr =
2891     Builder.CreateGEP(Addr, llvm::ConstantInt::get(CGF.Int32Ty, Offset),
2892                       "ap.next");
2893   Builder.CreateStore(NextAddr, VAListAddrAsBPP);
2894 
2895   return AddrTyped;
2896 }
2897 
2898 //===----------------------------------------------------------------------===//
2899 // NVPTX ABI Implementation
2900 //===----------------------------------------------------------------------===//
2901 
2902 namespace {
2903 
2904 class NVPTXABIInfo : public ABIInfo {
2905 public:
2906   NVPTXABIInfo(CodeGenTypes &CGT) : ABIInfo(CGT) {}
2907 
2908   ABIArgInfo classifyReturnType(QualType RetTy) const;
2909   ABIArgInfo classifyArgumentType(QualType Ty) const;
2910 
2911   virtual void computeInfo(CGFunctionInfo &FI) const;
2912   virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
2913                                  CodeGenFunction &CFG) const;
2914 };
2915 
2916 class NVPTXTargetCodeGenInfo : public TargetCodeGenInfo {
2917 public:
2918   NVPTXTargetCodeGenInfo(CodeGenTypes &CGT)
2919     : TargetCodeGenInfo(new NVPTXABIInfo(CGT)) {}
2920 
2921   virtual void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
2922                                    CodeGen::CodeGenModule &M) const;
2923 };
2924 
2925 ABIArgInfo NVPTXABIInfo::classifyReturnType(QualType RetTy) const {
2926   if (RetTy->isVoidType())
2927     return ABIArgInfo::getIgnore();
2928   if (isAggregateTypeForABI(RetTy))
2929     return ABIArgInfo::getIndirect(0);
2930   return ABIArgInfo::getDirect();
2931 }
2932 
2933 ABIArgInfo NVPTXABIInfo::classifyArgumentType(QualType Ty) const {
2934   if (isAggregateTypeForABI(Ty))
2935     return ABIArgInfo::getIndirect(0);
2936 
2937   return ABIArgInfo::getDirect();
2938 }
2939 
2940 void NVPTXABIInfo::computeInfo(CGFunctionInfo &FI) const {
2941   FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
2942   for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
2943        it != ie; ++it)
2944     it->info = classifyArgumentType(it->type);
2945 
2946   // Always honor user-specified calling convention.
2947   if (FI.getCallingConvention() != llvm::CallingConv::C)
2948     return;
2949 
2950   // Calling convention as default by an ABI.
2951   // We're still using the PTX_Kernel/PTX_Device calling conventions here,
2952   // but we should switch to NVVM metadata later on.
2953   llvm::CallingConv::ID DefaultCC;
2954   const LangOptions &LangOpts = getContext().getLangOpts();
2955   if (LangOpts.OpenCL || LangOpts.CUDA) {
2956     // If we are in OpenCL or CUDA mode, then default to device functions
2957     DefaultCC = llvm::CallingConv::PTX_Device;
2958   } else {
2959     // If we are in standard C/C++ mode, use the triple to decide on the default
2960     StringRef Env =
2961       getContext().getTargetInfo().getTriple().getEnvironmentName();
2962     if (Env == "device")
2963       DefaultCC = llvm::CallingConv::PTX_Device;
2964     else
2965       DefaultCC = llvm::CallingConv::PTX_Kernel;
2966   }
2967   FI.setEffectiveCallingConvention(DefaultCC);
2968 
2969 }
2970 
2971 llvm::Value *NVPTXABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
2972                                      CodeGenFunction &CFG) const {
2973   llvm_unreachable("NVPTX does not support varargs");
2974 }
2975 
2976 void NVPTXTargetCodeGenInfo::
2977 SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
2978                     CodeGen::CodeGenModule &M) const{
2979   const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
2980   if (!FD) return;
2981 
2982   llvm::Function *F = cast<llvm::Function>(GV);
2983 
2984   // Perform special handling in OpenCL mode
2985   if (M.getLangOpts().OpenCL) {
2986     // Use OpenCL function attributes to set proper calling conventions
2987     // By default, all functions are device functions
2988     if (FD->hasAttr<OpenCLKernelAttr>()) {
2989       // OpenCL __kernel functions get a kernel calling convention
2990       F->setCallingConv(llvm::CallingConv::PTX_Kernel);
2991       // And kernel functions are not subject to inlining
2992       F->addFnAttr(llvm::Attribute::NoInline);
2993     }
2994   }
2995 
2996   // Perform special handling in CUDA mode.
2997   if (M.getLangOpts().CUDA) {
2998     // CUDA __global__ functions get a kernel calling convention.  Since
2999     // __global__ functions cannot be called from the device, we do not
3000     // need to set the noinline attribute.
3001     if (FD->getAttr<CUDAGlobalAttr>())
3002       F->setCallingConv(llvm::CallingConv::PTX_Kernel);
3003   }
3004 }
3005 
3006 }
3007 
3008 //===----------------------------------------------------------------------===//
3009 // MBlaze ABI Implementation
3010 //===----------------------------------------------------------------------===//
3011 
3012 namespace {
3013 
3014 class MBlazeABIInfo : public ABIInfo {
3015 public:
3016   MBlazeABIInfo(CodeGenTypes &CGT) : ABIInfo(CGT) {}
3017 
3018   bool isPromotableIntegerType(QualType Ty) const;
3019 
3020   ABIArgInfo classifyReturnType(QualType RetTy) const;
3021   ABIArgInfo classifyArgumentType(QualType RetTy) const;
3022 
3023   virtual void computeInfo(CGFunctionInfo &FI) const {
3024     FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
3025     for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
3026          it != ie; ++it)
3027       it->info = classifyArgumentType(it->type);
3028   }
3029 
3030   virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
3031                                  CodeGenFunction &CGF) const;
3032 };
3033 
3034 class MBlazeTargetCodeGenInfo : public TargetCodeGenInfo {
3035 public:
3036   MBlazeTargetCodeGenInfo(CodeGenTypes &CGT)
3037     : TargetCodeGenInfo(new MBlazeABIInfo(CGT)) {}
3038   void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
3039                            CodeGen::CodeGenModule &M) const;
3040 };
3041 
3042 }
3043 
3044 bool MBlazeABIInfo::isPromotableIntegerType(QualType Ty) const {
3045   // MBlaze ABI requires all 8 and 16 bit quantities to be extended.
3046   if (const BuiltinType *BT = Ty->getAs<BuiltinType>())
3047     switch (BT->getKind()) {
3048     case BuiltinType::Bool:
3049     case BuiltinType::Char_S:
3050     case BuiltinType::Char_U:
3051     case BuiltinType::SChar:
3052     case BuiltinType::UChar:
3053     case BuiltinType::Short:
3054     case BuiltinType::UShort:
3055       return true;
3056     default:
3057       return false;
3058     }
3059   return false;
3060 }
3061 
3062 llvm::Value *MBlazeABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
3063                                       CodeGenFunction &CGF) const {
3064   // FIXME: Implement
3065   return 0;
3066 }
3067 
3068 
3069 ABIArgInfo MBlazeABIInfo::classifyReturnType(QualType RetTy) const {
3070   if (RetTy->isVoidType())
3071     return ABIArgInfo::getIgnore();
3072   if (isAggregateTypeForABI(RetTy))
3073     return ABIArgInfo::getIndirect(0);
3074 
3075   return (isPromotableIntegerType(RetTy) ?
3076           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
3077 }
3078 
3079 ABIArgInfo MBlazeABIInfo::classifyArgumentType(QualType Ty) const {
3080   if (isAggregateTypeForABI(Ty))
3081     return ABIArgInfo::getIndirect(0);
3082 
3083   return (isPromotableIntegerType(Ty) ?
3084           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
3085 }
3086 
3087 void MBlazeTargetCodeGenInfo::SetTargetAttributes(const Decl *D,
3088                                                   llvm::GlobalValue *GV,
3089                                                   CodeGen::CodeGenModule &M)
3090                                                   const {
3091   const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
3092   if (!FD) return;
3093 
3094   llvm::CallingConv::ID CC = llvm::CallingConv::C;
3095   if (FD->hasAttr<MBlazeInterruptHandlerAttr>())
3096     CC = llvm::CallingConv::MBLAZE_INTR;
3097   else if (FD->hasAttr<MBlazeSaveVolatilesAttr>())
3098     CC = llvm::CallingConv::MBLAZE_SVOL;
3099 
3100   if (CC != llvm::CallingConv::C) {
3101       // Handle 'interrupt_handler' attribute:
3102       llvm::Function *F = cast<llvm::Function>(GV);
3103 
3104       // Step 1: Set ISR calling convention.
3105       F->setCallingConv(CC);
3106 
3107       // Step 2: Add attributes goodness.
3108       F->addFnAttr(llvm::Attribute::NoInline);
3109   }
3110 
3111   // Step 3: Emit _interrupt_handler alias.
3112   if (CC == llvm::CallingConv::MBLAZE_INTR)
3113     new llvm::GlobalAlias(GV->getType(), llvm::Function::ExternalLinkage,
3114                           "_interrupt_handler", GV, &M.getModule());
3115 }
3116 
3117 
3118 //===----------------------------------------------------------------------===//
3119 // MSP430 ABI Implementation
3120 //===----------------------------------------------------------------------===//
3121 
3122 namespace {
3123 
3124 class MSP430TargetCodeGenInfo : public TargetCodeGenInfo {
3125 public:
3126   MSP430TargetCodeGenInfo(CodeGenTypes &CGT)
3127     : TargetCodeGenInfo(new DefaultABIInfo(CGT)) {}
3128   void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
3129                            CodeGen::CodeGenModule &M) const;
3130 };
3131 
3132 }
3133 
3134 void MSP430TargetCodeGenInfo::SetTargetAttributes(const Decl *D,
3135                                                   llvm::GlobalValue *GV,
3136                                              CodeGen::CodeGenModule &M) const {
3137   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
3138     if (const MSP430InterruptAttr *attr = FD->getAttr<MSP430InterruptAttr>()) {
3139       // Handle 'interrupt' attribute:
3140       llvm::Function *F = cast<llvm::Function>(GV);
3141 
3142       // Step 1: Set ISR calling convention.
3143       F->setCallingConv(llvm::CallingConv::MSP430_INTR);
3144 
3145       // Step 2: Add attributes goodness.
3146       F->addFnAttr(llvm::Attribute::NoInline);
3147 
3148       // Step 3: Emit ISR vector alias.
3149       unsigned Num = attr->getNumber() + 0xffe0;
3150       new llvm::GlobalAlias(GV->getType(), llvm::Function::ExternalLinkage,
3151                             "vector_" + Twine::utohexstr(Num),
3152                             GV, &M.getModule());
3153     }
3154   }
3155 }
3156 
3157 //===----------------------------------------------------------------------===//
3158 // MIPS ABI Implementation.  This works for both little-endian and
3159 // big-endian variants.
3160 //===----------------------------------------------------------------------===//
3161 
3162 namespace {
3163 class MipsABIInfo : public ABIInfo {
3164   bool IsO32;
3165   unsigned MinABIStackAlignInBytes;
3166   llvm::Type* CoerceToIntArgs(uint64_t TySize) const;
3167   llvm::Type* HandleAggregates(QualType Ty, uint64_t TySize) const;
3168   llvm::Type* returnAggregateInRegs(QualType RetTy, uint64_t Size) const;
3169   llvm::Type* getPaddingType(uint64_t Align, uint64_t Offset) const;
3170 public:
3171   MipsABIInfo(CodeGenTypes &CGT, bool _IsO32) :
3172     ABIInfo(CGT), IsO32(_IsO32), MinABIStackAlignInBytes(IsO32 ? 4 : 8) {}
3173 
3174   ABIArgInfo classifyReturnType(QualType RetTy) const;
3175   ABIArgInfo classifyArgumentType(QualType RetTy, uint64_t &Offset) const;
3176   virtual void computeInfo(CGFunctionInfo &FI) const;
3177   virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
3178                                  CodeGenFunction &CGF) const;
3179 };
3180 
3181 class MIPSTargetCodeGenInfo : public TargetCodeGenInfo {
3182   unsigned SizeOfUnwindException;
3183 public:
3184   MIPSTargetCodeGenInfo(CodeGenTypes &CGT, bool IsO32)
3185     : TargetCodeGenInfo(new MipsABIInfo(CGT, IsO32)),
3186       SizeOfUnwindException(IsO32 ? 24 : 32) {}
3187 
3188   int getDwarfEHStackPointer(CodeGen::CodeGenModule &CGM) const {
3189     return 29;
3190   }
3191 
3192   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
3193                                llvm::Value *Address) const;
3194 
3195   unsigned getSizeOfUnwindException() const {
3196     return SizeOfUnwindException;
3197   }
3198 };
3199 }
3200 
3201 llvm::Type* MipsABIInfo::CoerceToIntArgs(uint64_t TySize) const {
3202   SmallVector<llvm::Type*, 8> ArgList;
3203   llvm::IntegerType *IntTy = llvm::IntegerType::get(getVMContext(),
3204                                                     MinABIStackAlignInBytes * 8);
3205 
3206   // Add (TySize / MinABIStackAlignInBytes) args of IntTy.
3207   for (unsigned N = TySize / (MinABIStackAlignInBytes * 8); N; --N)
3208     ArgList.push_back(IntTy);
3209 
3210   // If necessary, add one more integer type to ArgList.
3211   unsigned R = TySize % (MinABIStackAlignInBytes * 8);
3212 
3213   if (R)
3214     ArgList.push_back(llvm::IntegerType::get(getVMContext(), R));
3215 
3216   return llvm::StructType::get(getVMContext(), ArgList);
3217 }
3218 
3219 // In N32/64, an aligned double precision floating point field is passed in
3220 // a register.
3221 llvm::Type* MipsABIInfo::HandleAggregates(QualType Ty, uint64_t TySize) const {
3222   if (IsO32)
3223     return CoerceToIntArgs(TySize);
3224 
3225   if (Ty->isComplexType())
3226     return CGT.ConvertType(Ty);
3227 
3228   const RecordType *RT = Ty->getAs<RecordType>();
3229 
3230   // Unions are passed in integer registers.
3231   if (!RT || !RT->isStructureOrClassType())
3232     return CoerceToIntArgs(TySize);
3233 
3234   const RecordDecl *RD = RT->getDecl();
3235   const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
3236   assert(!(TySize % 8) && "Size of structure must be multiple of 8.");
3237 
3238   uint64_t LastOffset = 0;
3239   unsigned idx = 0;
3240   llvm::IntegerType *I64 = llvm::IntegerType::get(getVMContext(), 64);
3241   SmallVector<llvm::Type*, 8> ArgList;
3242 
3243   // Iterate over fields in the struct/class and check if there are any aligned
3244   // double fields.
3245   for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
3246        i != e; ++i, ++idx) {
3247     const QualType Ty = i->getType();
3248     const BuiltinType *BT = Ty->getAs<BuiltinType>();
3249 
3250     if (!BT || BT->getKind() != BuiltinType::Double)
3251       continue;
3252 
3253     uint64_t Offset = Layout.getFieldOffset(idx);
3254     if (Offset % 64) // Ignore doubles that are not aligned.
3255       continue;
3256 
3257     // Add ((Offset - LastOffset) / 64) args of type i64.
3258     for (unsigned j = (Offset - LastOffset) / 64; j > 0; --j)
3259       ArgList.push_back(I64);
3260 
3261     // Add double type.
3262     ArgList.push_back(llvm::Type::getDoubleTy(getVMContext()));
3263     LastOffset = Offset + 64;
3264   }
3265 
3266   // Add ((TySize - LastOffset) / 64) args of type i64.
3267   for (unsigned N = (TySize - LastOffset) / 64; N; --N)
3268     ArgList.push_back(I64);
3269 
3270   // If the size of the remainder is not zero, add one more integer type to
3271   // ArgList.
3272   unsigned R = (TySize - LastOffset) % 64;
3273   if (R)
3274     ArgList.push_back(llvm::IntegerType::get(getVMContext(), R));
3275 
3276   return llvm::StructType::get(getVMContext(), ArgList);
3277 }
3278 
3279 llvm::Type *MipsABIInfo::getPaddingType(uint64_t Align, uint64_t Offset) const {
3280   assert((Offset % MinABIStackAlignInBytes) == 0);
3281 
3282   if ((Align - 1) & Offset)
3283     return llvm::IntegerType::get(getVMContext(), MinABIStackAlignInBytes * 8);
3284 
3285   return 0;
3286 }
3287 
3288 ABIArgInfo
3289 MipsABIInfo::classifyArgumentType(QualType Ty, uint64_t &Offset) const {
3290   uint64_t OrigOffset = Offset;
3291   uint64_t TySize = getContext().getTypeSize(Ty);
3292   uint64_t Align = getContext().getTypeAlign(Ty) / 8;
3293 
3294   Align = std::max(Align, (uint64_t)MinABIStackAlignInBytes);
3295   Offset = llvm::RoundUpToAlignment(Offset, Align);
3296   Offset += llvm::RoundUpToAlignment(TySize, Align * 8) / 8;
3297 
3298   if (isAggregateTypeForABI(Ty)) {
3299     // Ignore empty aggregates.
3300     if (TySize == 0)
3301       return ABIArgInfo::getIgnore();
3302 
3303     // Records with non trivial destructors/constructors should not be passed
3304     // by value.
3305     if (isRecordWithNonTrivialDestructorOrCopyConstructor(Ty)) {
3306       Offset = OrigOffset + MinABIStackAlignInBytes;
3307       return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
3308     }
3309 
3310     // If we have reached here, aggregates are passed directly by coercing to
3311     // another structure type. Padding is inserted if the offset of the
3312     // aggregate is unaligned.
3313     return ABIArgInfo::getDirect(HandleAggregates(Ty, TySize), 0,
3314                                  getPaddingType(Align, OrigOffset));
3315   }
3316 
3317   // Treat an enum type as its underlying type.
3318   if (const EnumType *EnumTy = Ty->getAs<EnumType>())
3319     Ty = EnumTy->getDecl()->getIntegerType();
3320 
3321   if (Ty->isPromotableIntegerType())
3322     return ABIArgInfo::getExtend();
3323 
3324   return ABIArgInfo::getDirect(0, 0, getPaddingType(Align, OrigOffset));
3325 }
3326 
3327 llvm::Type*
3328 MipsABIInfo::returnAggregateInRegs(QualType RetTy, uint64_t Size) const {
3329   const RecordType *RT = RetTy->getAs<RecordType>();
3330   SmallVector<llvm::Type*, 2> RTList;
3331 
3332   if (RT && RT->isStructureOrClassType()) {
3333     const RecordDecl *RD = RT->getDecl();
3334     const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
3335     unsigned FieldCnt = Layout.getFieldCount();
3336 
3337     // N32/64 returns struct/classes in floating point registers if the
3338     // following conditions are met:
3339     // 1. The size of the struct/class is no larger than 128-bit.
3340     // 2. The struct/class has one or two fields all of which are floating
3341     //    point types.
3342     // 3. The offset of the first field is zero (this follows what gcc does).
3343     //
3344     // Any other composite results are returned in integer registers.
3345     //
3346     if (FieldCnt && (FieldCnt <= 2) && !Layout.getFieldOffset(0)) {
3347       RecordDecl::field_iterator b = RD->field_begin(), e = RD->field_end();
3348       for (; b != e; ++b) {
3349         const BuiltinType *BT = b->getType()->getAs<BuiltinType>();
3350 
3351         if (!BT || !BT->isFloatingPoint())
3352           break;
3353 
3354         RTList.push_back(CGT.ConvertType(b->getType()));
3355       }
3356 
3357       if (b == e)
3358         return llvm::StructType::get(getVMContext(), RTList,
3359                                      RD->hasAttr<PackedAttr>());
3360 
3361       RTList.clear();
3362     }
3363   }
3364 
3365   RTList.push_back(llvm::IntegerType::get(getVMContext(),
3366                                           std::min(Size, (uint64_t)64)));
3367   if (Size > 64)
3368     RTList.push_back(llvm::IntegerType::get(getVMContext(), Size - 64));
3369 
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       if (!IsO32 && !isRecordWithNonTrivialDestructorOrCopyConstructor(RetTy))
3385         return ABIArgInfo::getDirect(returnAggregateInRegs(RetTy, Size));
3386     }
3387 
3388     return ABIArgInfo::getIndirect(0);
3389   }
3390 
3391   // Treat an enum type as its underlying type.
3392   if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
3393     RetTy = EnumTy->getDecl()->getIntegerType();
3394 
3395   return (RetTy->isPromotableIntegerType() ?
3396           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
3397 }
3398 
3399 void MipsABIInfo::computeInfo(CGFunctionInfo &FI) const {
3400   ABIArgInfo &RetInfo = FI.getReturnInfo();
3401   RetInfo = classifyReturnType(FI.getReturnType());
3402 
3403   // Check if a pointer to an aggregate is passed as a hidden argument.
3404   uint64_t Offset = RetInfo.isIndirect() ? MinABIStackAlignInBytes : 0;
3405 
3406   for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
3407        it != ie; ++it)
3408     it->info = classifyArgumentType(it->type, Offset);
3409 }
3410 
3411 llvm::Value* MipsABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
3412                                     CodeGenFunction &CGF) const {
3413   llvm::Type *BP = CGF.Int8PtrTy;
3414   llvm::Type *BPP = CGF.Int8PtrPtrTy;
3415 
3416   CGBuilderTy &Builder = CGF.Builder;
3417   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP, "ap");
3418   llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
3419   int64_t TypeAlign = getContext().getTypeAlign(Ty) / 8;
3420   llvm::Type *PTy = llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
3421   llvm::Value *AddrTyped;
3422   unsigned PtrWidth = getContext().getTargetInfo().getPointerWidth(0);
3423   llvm::IntegerType *IntTy = (PtrWidth == 32) ? CGF.Int32Ty : CGF.Int64Ty;
3424 
3425   if (TypeAlign > MinABIStackAlignInBytes) {
3426     llvm::Value *AddrAsInt = CGF.Builder.CreatePtrToInt(Addr, IntTy);
3427     llvm::Value *Inc = llvm::ConstantInt::get(IntTy, TypeAlign - 1);
3428     llvm::Value *Mask = llvm::ConstantInt::get(IntTy, -TypeAlign);
3429     llvm::Value *Add = CGF.Builder.CreateAdd(AddrAsInt, Inc);
3430     llvm::Value *And = CGF.Builder.CreateAnd(Add, Mask);
3431     AddrTyped = CGF.Builder.CreateIntToPtr(And, PTy);
3432   }
3433   else
3434     AddrTyped = Builder.CreateBitCast(Addr, PTy);
3435 
3436   llvm::Value *AlignedAddr = Builder.CreateBitCast(AddrTyped, BP);
3437   TypeAlign = std::max((unsigned)TypeAlign, MinABIStackAlignInBytes);
3438   uint64_t Offset =
3439     llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, TypeAlign);
3440   llvm::Value *NextAddr =
3441     Builder.CreateGEP(AlignedAddr, llvm::ConstantInt::get(IntTy, Offset),
3442                       "ap.next");
3443   Builder.CreateStore(NextAddr, VAListAddrAsBPP);
3444 
3445   return AddrTyped;
3446 }
3447 
3448 bool
3449 MIPSTargetCodeGenInfo::initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
3450                                                llvm::Value *Address) const {
3451   // This information comes from gcc's implementation, which seems to
3452   // as canonical as it gets.
3453 
3454   // Everything on MIPS is 4 bytes.  Double-precision FP registers
3455   // are aliased to pairs of single-precision FP registers.
3456   llvm::Value *Four8 = llvm::ConstantInt::get(CGF.Int8Ty, 4);
3457 
3458   // 0-31 are the general purpose registers, $0 - $31.
3459   // 32-63 are the floating-point registers, $f0 - $f31.
3460   // 64 and 65 are the multiply/divide registers, $hi and $lo.
3461   // 66 is the (notional, I think) register for signal-handler return.
3462   AssignToArrayRange(CGF.Builder, Address, Four8, 0, 65);
3463 
3464   // 67-74 are the floating-point status registers, $fcc0 - $fcc7.
3465   // They are one bit wide and ignored here.
3466 
3467   // 80-111 are the coprocessor 0 registers, $c0r0 - $c0r31.
3468   // (coprocessor 1 is the FP unit)
3469   // 112-143 are the coprocessor 2 registers, $c2r0 - $c2r31.
3470   // 144-175 are the coprocessor 3 registers, $c3r0 - $c3r31.
3471   // 176-181 are the DSP accumulator registers.
3472   AssignToArrayRange(CGF.Builder, Address, Four8, 80, 181);
3473   return false;
3474 }
3475 
3476 //===----------------------------------------------------------------------===//
3477 // TCE ABI Implementation (see http://tce.cs.tut.fi). Uses mostly the defaults.
3478 // Currently subclassed only to implement custom OpenCL C function attribute
3479 // handling.
3480 //===----------------------------------------------------------------------===//
3481 
3482 namespace {
3483 
3484 class TCETargetCodeGenInfo : public DefaultTargetCodeGenInfo {
3485 public:
3486   TCETargetCodeGenInfo(CodeGenTypes &CGT)
3487     : DefaultTargetCodeGenInfo(CGT) {}
3488 
3489   virtual void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
3490                                    CodeGen::CodeGenModule &M) const;
3491 };
3492 
3493 void TCETargetCodeGenInfo::SetTargetAttributes(const Decl *D,
3494                                                llvm::GlobalValue *GV,
3495                                                CodeGen::CodeGenModule &M) const {
3496   const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
3497   if (!FD) return;
3498 
3499   llvm::Function *F = cast<llvm::Function>(GV);
3500 
3501   if (M.getLangOpts().OpenCL) {
3502     if (FD->hasAttr<OpenCLKernelAttr>()) {
3503       // OpenCL C Kernel functions are not subject to inlining
3504       F->addFnAttr(llvm::Attribute::NoInline);
3505 
3506       if (FD->hasAttr<ReqdWorkGroupSizeAttr>()) {
3507 
3508         // Convert the reqd_work_group_size() attributes to metadata.
3509         llvm::LLVMContext &Context = F->getContext();
3510         llvm::NamedMDNode *OpenCLMetadata =
3511             M.getModule().getOrInsertNamedMetadata("opencl.kernel_wg_size_info");
3512 
3513         SmallVector<llvm::Value*, 5> Operands;
3514         Operands.push_back(F);
3515 
3516         Operands.push_back(llvm::Constant::getIntegerValue(M.Int32Ty,
3517                              llvm::APInt(32,
3518                              FD->getAttr<ReqdWorkGroupSizeAttr>()->getXDim())));
3519         Operands.push_back(llvm::Constant::getIntegerValue(M.Int32Ty,
3520                              llvm::APInt(32,
3521                                FD->getAttr<ReqdWorkGroupSizeAttr>()->getYDim())));
3522         Operands.push_back(llvm::Constant::getIntegerValue(M.Int32Ty,
3523                              llvm::APInt(32,
3524                                FD->getAttr<ReqdWorkGroupSizeAttr>()->getZDim())));
3525 
3526         // Add a boolean constant operand for "required" (true) or "hint" (false)
3527         // for implementing the work_group_size_hint attr later. Currently
3528         // always true as the hint is not yet implemented.
3529         Operands.push_back(llvm::ConstantInt::getTrue(Context));
3530         OpenCLMetadata->addOperand(llvm::MDNode::get(Context, Operands));
3531       }
3532     }
3533   }
3534 }
3535 
3536 }
3537 
3538 //===----------------------------------------------------------------------===//
3539 // Hexagon ABI Implementation
3540 //===----------------------------------------------------------------------===//
3541 
3542 namespace {
3543 
3544 class HexagonABIInfo : public ABIInfo {
3545 
3546 
3547 public:
3548   HexagonABIInfo(CodeGenTypes &CGT) : ABIInfo(CGT) {}
3549 
3550 private:
3551 
3552   ABIArgInfo classifyReturnType(QualType RetTy) const;
3553   ABIArgInfo classifyArgumentType(QualType RetTy) const;
3554 
3555   virtual void computeInfo(CGFunctionInfo &FI) const;
3556 
3557   virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
3558                                  CodeGenFunction &CGF) const;
3559 };
3560 
3561 class HexagonTargetCodeGenInfo : public TargetCodeGenInfo {
3562 public:
3563   HexagonTargetCodeGenInfo(CodeGenTypes &CGT)
3564     :TargetCodeGenInfo(new HexagonABIInfo(CGT)) {}
3565 
3566   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const {
3567     return 29;
3568   }
3569 };
3570 
3571 }
3572 
3573 void HexagonABIInfo::computeInfo(CGFunctionInfo &FI) const {
3574   FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
3575   for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
3576        it != ie; ++it)
3577     it->info = classifyArgumentType(it->type);
3578 }
3579 
3580 ABIArgInfo HexagonABIInfo::classifyArgumentType(QualType Ty) const {
3581   if (!isAggregateTypeForABI(Ty)) {
3582     // Treat an enum type as its underlying type.
3583     if (const EnumType *EnumTy = Ty->getAs<EnumType>())
3584       Ty = EnumTy->getDecl()->getIntegerType();
3585 
3586     return (Ty->isPromotableIntegerType() ?
3587             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
3588   }
3589 
3590   // Ignore empty records.
3591   if (isEmptyRecord(getContext(), Ty, true))
3592     return ABIArgInfo::getIgnore();
3593 
3594   // Structures with either a non-trivial destructor or a non-trivial
3595   // copy constructor are always indirect.
3596   if (isRecordWithNonTrivialDestructorOrCopyConstructor(Ty))
3597     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
3598 
3599   uint64_t Size = getContext().getTypeSize(Ty);
3600   if (Size > 64)
3601     return ABIArgInfo::getIndirect(0, /*ByVal=*/true);
3602     // Pass in the smallest viable integer type.
3603   else if (Size > 32)
3604       return ABIArgInfo::getDirect(llvm::Type::getInt64Ty(getVMContext()));
3605   else if (Size > 16)
3606       return ABIArgInfo::getDirect(llvm::Type::getInt32Ty(getVMContext()));
3607   else if (Size > 8)
3608       return ABIArgInfo::getDirect(llvm::Type::getInt16Ty(getVMContext()));
3609   else
3610       return ABIArgInfo::getDirect(llvm::Type::getInt8Ty(getVMContext()));
3611 }
3612 
3613 ABIArgInfo HexagonABIInfo::classifyReturnType(QualType RetTy) const {
3614   if (RetTy->isVoidType())
3615     return ABIArgInfo::getIgnore();
3616 
3617   // Large vector types should be returned via memory.
3618   if (RetTy->isVectorType() && getContext().getTypeSize(RetTy) > 64)
3619     return ABIArgInfo::getIndirect(0);
3620 
3621   if (!isAggregateTypeForABI(RetTy)) {
3622     // Treat an enum type as its underlying type.
3623     if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
3624       RetTy = EnumTy->getDecl()->getIntegerType();
3625 
3626     return (RetTy->isPromotableIntegerType() ?
3627             ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
3628   }
3629 
3630   // Structures with either a non-trivial destructor or a non-trivial
3631   // copy constructor are always indirect.
3632   if (isRecordWithNonTrivialDestructorOrCopyConstructor(RetTy))
3633     return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
3634 
3635   if (isEmptyRecord(getContext(), RetTy, true))
3636     return ABIArgInfo::getIgnore();
3637 
3638   // Aggregates <= 8 bytes are returned in r0; other aggregates
3639   // are returned indirectly.
3640   uint64_t Size = getContext().getTypeSize(RetTy);
3641   if (Size <= 64) {
3642     // Return in the smallest viable integer type.
3643     if (Size <= 8)
3644       return ABIArgInfo::getDirect(llvm::Type::getInt8Ty(getVMContext()));
3645     if (Size <= 16)
3646       return ABIArgInfo::getDirect(llvm::Type::getInt16Ty(getVMContext()));
3647     if (Size <= 32)
3648       return ABIArgInfo::getDirect(llvm::Type::getInt32Ty(getVMContext()));
3649     return ABIArgInfo::getDirect(llvm::Type::getInt64Ty(getVMContext()));
3650   }
3651 
3652   return ABIArgInfo::getIndirect(0, /*ByVal=*/true);
3653 }
3654 
3655 llvm::Value *HexagonABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
3656                                        CodeGenFunction &CGF) const {
3657   // FIXME: Need to handle alignment
3658   llvm::Type *BPP = CGF.Int8PtrPtrTy;
3659 
3660   CGBuilderTy &Builder = CGF.Builder;
3661   llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP,
3662                                                        "ap");
3663   llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
3664   llvm::Type *PTy =
3665     llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
3666   llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy);
3667 
3668   uint64_t Offset =
3669     llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, 4);
3670   llvm::Value *NextAddr =
3671     Builder.CreateGEP(Addr, llvm::ConstantInt::get(CGF.Int32Ty, Offset),
3672                       "ap.next");
3673   Builder.CreateStore(NextAddr, VAListAddrAsBPP);
3674 
3675   return AddrTyped;
3676 }
3677 
3678 
3679 const TargetCodeGenInfo &CodeGenModule::getTargetCodeGenInfo() {
3680   if (TheTargetCodeGenInfo)
3681     return *TheTargetCodeGenInfo;
3682 
3683   const llvm::Triple &Triple = getContext().getTargetInfo().getTriple();
3684   switch (Triple.getArch()) {
3685   default:
3686     return *(TheTargetCodeGenInfo = new DefaultTargetCodeGenInfo(Types));
3687 
3688   case llvm::Triple::mips:
3689   case llvm::Triple::mipsel:
3690     return *(TheTargetCodeGenInfo = new MIPSTargetCodeGenInfo(Types, true));
3691 
3692   case llvm::Triple::mips64:
3693   case llvm::Triple::mips64el:
3694     return *(TheTargetCodeGenInfo = new MIPSTargetCodeGenInfo(Types, false));
3695 
3696   case llvm::Triple::arm:
3697   case llvm::Triple::thumb:
3698     {
3699       ARMABIInfo::ABIKind Kind = ARMABIInfo::AAPCS;
3700 
3701       if (strcmp(getContext().getTargetInfo().getABI(), "apcs-gnu") == 0)
3702         Kind = ARMABIInfo::APCS;
3703       else if (CodeGenOpts.FloatABI == "hard")
3704         Kind = ARMABIInfo::AAPCS_VFP;
3705 
3706       return *(TheTargetCodeGenInfo = new ARMTargetCodeGenInfo(Types, Kind));
3707     }
3708 
3709   case llvm::Triple::ppc:
3710     return *(TheTargetCodeGenInfo = new PPC32TargetCodeGenInfo(Types));
3711   case llvm::Triple::ppc64:
3712     return *(TheTargetCodeGenInfo = new PPC64TargetCodeGenInfo(Types));
3713 
3714   case llvm::Triple::nvptx:
3715   case llvm::Triple::nvptx64:
3716     return *(TheTargetCodeGenInfo = new NVPTXTargetCodeGenInfo(Types));
3717 
3718   case llvm::Triple::mblaze:
3719     return *(TheTargetCodeGenInfo = new MBlazeTargetCodeGenInfo(Types));
3720 
3721   case llvm::Triple::msp430:
3722     return *(TheTargetCodeGenInfo = new MSP430TargetCodeGenInfo(Types));
3723 
3724   case llvm::Triple::tce:
3725     return *(TheTargetCodeGenInfo = new TCETargetCodeGenInfo(Types));
3726 
3727   case llvm::Triple::x86: {
3728     bool DisableMMX = strcmp(getContext().getTargetInfo().getABI(), "no-mmx") == 0;
3729 
3730     if (Triple.isOSDarwin())
3731       return *(TheTargetCodeGenInfo =
3732                new X86_32TargetCodeGenInfo(
3733                  Types, true, true, DisableMMX, false));
3734 
3735     switch (Triple.getOS()) {
3736     case llvm::Triple::Cygwin:
3737     case llvm::Triple::MinGW32:
3738     case llvm::Triple::AuroraUX:
3739     case llvm::Triple::DragonFly:
3740     case llvm::Triple::FreeBSD:
3741     case llvm::Triple::OpenBSD:
3742       return *(TheTargetCodeGenInfo =
3743                new X86_32TargetCodeGenInfo(
3744                  Types, false, true, DisableMMX, false));
3745 
3746     case llvm::Triple::Win32:
3747       return *(TheTargetCodeGenInfo =
3748                new X86_32TargetCodeGenInfo(
3749                  Types, false, true, DisableMMX, true));
3750 
3751     default:
3752       return *(TheTargetCodeGenInfo =
3753                new X86_32TargetCodeGenInfo(
3754                  Types, false, false, DisableMMX, false));
3755     }
3756   }
3757 
3758   case llvm::Triple::x86_64: {
3759     bool HasAVX = strcmp(getContext().getTargetInfo().getABI(), "avx") == 0;
3760 
3761     switch (Triple.getOS()) {
3762     case llvm::Triple::Win32:
3763     case llvm::Triple::MinGW32:
3764     case llvm::Triple::Cygwin:
3765       return *(TheTargetCodeGenInfo = new WinX86_64TargetCodeGenInfo(Types));
3766     default:
3767       return *(TheTargetCodeGenInfo = new X86_64TargetCodeGenInfo(Types,
3768                                                                   HasAVX));
3769     }
3770   }
3771   case llvm::Triple::hexagon:
3772     return *(TheTargetCodeGenInfo = new HexagonTargetCodeGenInfo(Types));
3773   }
3774 }
3775