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clang-p2996/clang/lib/CodeGen/CGCall.cpp
Douglas Gregor deaad8cc34 Create a new TypeNodes.def file that enumerates all of the types, 
giving them rough classifications (normal types, never-canonical
types, always-dependent types, abstract type representations) and
making it far easier to make sure that we've hit all of the cases when
decoding types. 

Switched some switch() statements on the type class over to using this
mechanism, and filtering out those things we don't care about. For
example, CodeGen should never see always-dependent or non-canonical
types, while debug info generation should never see always-dependent
types. More switch() statements on the type class need to be moved 
over to using this approach, so that we'll get warnings when we add a
new type then fail to account for it somewhere in the compiler.

As part of this, some types have been renamed:

  TypeOfExpr -> TypeOfExprType
  FunctionTypeProto -> FunctionProtoType
  FunctionTypeNoProto -> FunctionNoProtoType

There shouldn't be any functionality change...

llvm-svn: 65591
2009-02-26 23:50:07 +00:00

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66 KiB
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//===----- CGCall.h - Encapsulate calling convention details ----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// These classes wrap the information about a call or function
// definition used to handle ABI compliancy.
//
//===----------------------------------------------------------------------===//
#include "CGCall.h"
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/RecordLayout.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Attributes.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetData.h"
#include "ABIInfo.h"
using namespace clang;
using namespace CodeGen;
/***/
// FIXME: Use iterator and sidestep silly type array creation.
const
CGFunctionInfo &CodeGenTypes::getFunctionInfo(const FunctionNoProtoType *FTNP) {
return getFunctionInfo(FTNP->getResultType(),
llvm::SmallVector<QualType, 16>());
}
const
CGFunctionInfo &CodeGenTypes::getFunctionInfo(const FunctionProtoType *FTP) {
llvm::SmallVector<QualType, 16> ArgTys;
// FIXME: Kill copy.
for (unsigned i = 0, e = FTP->getNumArgs(); i != e; ++i)
ArgTys.push_back(FTP->getArgType(i));
return getFunctionInfo(FTP->getResultType(), ArgTys);
}
const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const FunctionDecl *FD) {
const FunctionType *FTy = FD->getType()->getAsFunctionType();
if (const FunctionProtoType *FTP = dyn_cast<FunctionProtoType>(FTy))
return getFunctionInfo(FTP);
return getFunctionInfo(cast<FunctionNoProtoType>(FTy));
}
const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const ObjCMethodDecl *MD) {
llvm::SmallVector<QualType, 16> ArgTys;
ArgTys.push_back(MD->getSelfDecl()->getType());
ArgTys.push_back(Context.getObjCSelType());
// FIXME: Kill copy?
for (ObjCMethodDecl::param_iterator i = MD->param_begin(),
e = MD->param_end(); i != e; ++i)
ArgTys.push_back((*i)->getType());
return getFunctionInfo(MD->getResultType(), ArgTys);
}
const CGFunctionInfo &CodeGenTypes::getFunctionInfo(QualType ResTy,
const CallArgList &Args) {
// FIXME: Kill copy.
llvm::SmallVector<QualType, 16> ArgTys;
for (CallArgList::const_iterator i = Args.begin(), e = Args.end();
i != e; ++i)
ArgTys.push_back(i->second);
return getFunctionInfo(ResTy, ArgTys);
}
const CGFunctionInfo &CodeGenTypes::getFunctionInfo(QualType ResTy,
const FunctionArgList &Args) {
// FIXME: Kill copy.
llvm::SmallVector<QualType, 16> ArgTys;
for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end();
i != e; ++i)
ArgTys.push_back(i->second);
return getFunctionInfo(ResTy, ArgTys);
}
const CGFunctionInfo &CodeGenTypes::getFunctionInfo(QualType ResTy,
const llvm::SmallVector<QualType, 16> &ArgTys) {
// Lookup or create unique function info.
llvm::FoldingSetNodeID ID;
CGFunctionInfo::Profile(ID, ResTy, ArgTys.begin(), ArgTys.end());
void *InsertPos = 0;
CGFunctionInfo *FI = FunctionInfos.FindNodeOrInsertPos(ID, InsertPos);
if (FI)
return *FI;
// Construct the function info.
FI = new CGFunctionInfo(ResTy, ArgTys);
FunctionInfos.InsertNode(FI, InsertPos);
// Compute ABI information.
getABIInfo().computeInfo(*FI, getContext());
return *FI;
}
/***/
ABIInfo::~ABIInfo() {}
void ABIArgInfo::dump() const {
fprintf(stderr, "(ABIArgInfo Kind=");
switch (TheKind) {
case Direct:
fprintf(stderr, "Direct");
break;
case Ignore:
fprintf(stderr, "Ignore");
break;
case Coerce:
fprintf(stderr, "Coerce Type=");
getCoerceToType()->print(llvm::errs());
// FIXME: This is ridiculous.
llvm::errs().flush();
break;
case Indirect:
fprintf(stderr, "Indirect Align=%d", getIndirectAlign());
break;
case Expand:
fprintf(stderr, "Expand");
break;
}
fprintf(stderr, ")\n");
}
/***/
/// isEmptyStruct - Return true iff a structure has no non-empty
/// members. Note that a structure with a flexible array member is not
/// considered empty.
static bool isEmptyStruct(QualType T) {
const RecordType *RT = T->getAsStructureType();
if (!RT)
return 0;
const RecordDecl *RD = RT->getDecl();
if (RD->hasFlexibleArrayMember())
return false;
for (RecordDecl::field_iterator i = RD->field_begin(),
e = RD->field_end(); i != e; ++i) {
const FieldDecl *FD = *i;
if (!isEmptyStruct(FD->getType()))
return false;
}
return true;
}
/// isSingleElementStruct - Determine if a structure is a "single
/// element struct", i.e. it has exactly one non-empty field or
/// exactly one field which is itself a single element
/// struct. Structures with flexible array members are never
/// considered single element structs.
///
/// \return The field declaration for the single non-empty field, if
/// it exists.
static const FieldDecl *isSingleElementStruct(QualType T) {
const RecordType *RT = T->getAsStructureType();
if (!RT)
return 0;
const RecordDecl *RD = RT->getDecl();
if (RD->hasFlexibleArrayMember())
return 0;
const FieldDecl *Found = 0;
for (RecordDecl::field_iterator i = RD->field_begin(),
e = RD->field_end(); i != e; ++i) {
const FieldDecl *FD = *i;
QualType FT = FD->getType();
if (isEmptyStruct(FT)) {
// Ignore
} else if (Found) {
return 0;
} else if (!CodeGenFunction::hasAggregateLLVMType(FT)) {
Found = FD;
} else {
Found = isSingleElementStruct(FT);
if (!Found)
return 0;
}
}
return Found;
}
static bool is32Or64BitBasicType(QualType Ty, ASTContext &Context) {
if (!Ty->getAsBuiltinType() && !Ty->isPointerType())
return false;
uint64_t Size = Context.getTypeSize(Ty);
return Size == 32 || Size == 64;
}
static bool areAllFields32Or64BitBasicType(const RecordDecl *RD,
ASTContext &Context) {
for (RecordDecl::field_iterator i = RD->field_begin(),
e = RD->field_end(); i != e; ++i) {
const FieldDecl *FD = *i;
if (!is32Or64BitBasicType(FD->getType(), Context))
return false;
// If this is a bit-field we need to make sure it is still a
// 32-bit or 64-bit type.
if (Expr *BW = FD->getBitWidth()) {
unsigned Width = BW->getIntegerConstantExprValue(Context).getZExtValue();
if (Width <= 16)
return false;
}
}
return true;
}
namespace {
/// DefaultABIInfo - The default implementation for ABI specific
/// details. This implementation provides information which results in
/// self-consistent and sensible LLVM IR generation, but does not
/// conform to any particular ABI.
class DefaultABIInfo : public ABIInfo {
ABIArgInfo classifyReturnType(QualType RetTy,
ASTContext &Context) const;
ABIArgInfo classifyArgumentType(QualType RetTy,
ASTContext &Context) const;
virtual void computeInfo(CGFunctionInfo &FI, ASTContext &Context) const {
FI.getReturnInfo() = classifyReturnType(FI.getReturnType(), Context);
for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
it != ie; ++it)
it->info = classifyArgumentType(it->type, Context);
}
virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
CodeGenFunction &CGF) const;
};
/// X86_32ABIInfo - The X86-32 ABI information.
class X86_32ABIInfo : public ABIInfo {
public:
ABIArgInfo classifyReturnType(QualType RetTy,
ASTContext &Context) const;
ABIArgInfo classifyArgumentType(QualType RetTy,
ASTContext &Context) const;
virtual void computeInfo(CGFunctionInfo &FI, ASTContext &Context) const {
FI.getReturnInfo() = classifyReturnType(FI.getReturnType(), Context);
for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
it != ie; ++it)
it->info = classifyArgumentType(it->type, Context);
}
virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
CodeGenFunction &CGF) const;
};
}
ABIArgInfo X86_32ABIInfo::classifyReturnType(QualType RetTy,
ASTContext &Context) const {
if (RetTy->isVoidType()) {
return ABIArgInfo::getIgnore();
} else if (CodeGenFunction::hasAggregateLLVMType(RetTy)) {
// Classify "single element" structs as their element type.
const FieldDecl *SeltFD = isSingleElementStruct(RetTy);
if (SeltFD) {
QualType SeltTy = SeltFD->getType()->getDesugaredType();
if (const BuiltinType *BT = SeltTy->getAsBuiltinType()) {
// FIXME: This is gross, it would be nice if we could just
// pass back SeltTy and have clients deal with it. Is it worth
// supporting coerce to both LLVM and clang Types?
if (BT->isIntegerType()) {
uint64_t Size = Context.getTypeSize(SeltTy);
return ABIArgInfo::getCoerce(llvm::IntegerType::get((unsigned) Size));
} else if (BT->getKind() == BuiltinType::Float) {
return ABIArgInfo::getCoerce(llvm::Type::FloatTy);
} else if (BT->getKind() == BuiltinType::Double) {
return ABIArgInfo::getCoerce(llvm::Type::DoubleTy);
}
} else if (SeltTy->isPointerType()) {
// FIXME: It would be really nice if this could come out as
// the proper pointer type.
llvm::Type *PtrTy =
llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
return ABIArgInfo::getCoerce(PtrTy);
}
}
uint64_t Size = Context.getTypeSize(RetTy);
if (Size == 8) {
return ABIArgInfo::getCoerce(llvm::Type::Int8Ty);
} else if (Size == 16) {
return ABIArgInfo::getCoerce(llvm::Type::Int16Ty);
} else if (Size == 32) {
return ABIArgInfo::getCoerce(llvm::Type::Int32Ty);
} else if (Size == 64) {
return ABIArgInfo::getCoerce(llvm::Type::Int64Ty);
} else {
return ABIArgInfo::getIndirect(0);
}
} else {
return ABIArgInfo::getDirect();
}
}
ABIArgInfo X86_32ABIInfo::classifyArgumentType(QualType Ty,
ASTContext &Context) const {
// FIXME: Set alignment on indirect arguments.
if (CodeGenFunction::hasAggregateLLVMType(Ty)) {
// Structures with flexible arrays are always indirect.
if (const RecordType *RT = Ty->getAsStructureType())
if (RT->getDecl()->hasFlexibleArrayMember())
return ABIArgInfo::getIndirect(0);
// Ignore empty structs.
uint64_t Size = Context.getTypeSize(Ty);
if (Ty->isStructureType() && Size == 0)
return ABIArgInfo::getIgnore();
// Expand structs with size <= 128-bits which consist only of
// basic types (int, long long, float, double, xxx*). This is
// non-recursive and does not ignore empty fields.
if (const RecordType *RT = Ty->getAsStructureType()) {
if (Context.getTypeSize(Ty) <= 4*32 &&
areAllFields32Or64BitBasicType(RT->getDecl(), Context))
return ABIArgInfo::getExpand();
}
return ABIArgInfo::getIndirect(0);
} else {
return ABIArgInfo::getDirect();
}
}
llvm::Value *X86_32ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
CodeGenFunction &CGF) const {
const llvm::Type *BP = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
const llvm::Type *BPP = llvm::PointerType::getUnqual(BP);
CGBuilderTy &Builder = CGF.Builder;
llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP,
"ap");
llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
llvm::Type *PTy =
llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy);
uint64_t Offset =
llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, 4);
llvm::Value *NextAddr =
Builder.CreateGEP(Addr,
llvm::ConstantInt::get(llvm::Type::Int32Ty, Offset),
"ap.next");
Builder.CreateStore(NextAddr, VAListAddrAsBPP);
return AddrTyped;
}
namespace {
/// X86_64ABIInfo - The X86_64 ABI information.
class X86_64ABIInfo : public ABIInfo {
enum Class {
Integer = 0,
SSE,
SSEUp,
X87,
X87Up,
ComplexX87,
NoClass,
Memory
};
/// merge - Implement the X86_64 ABI merging algorithm.
///
/// Merge an accumulating classification \arg Accum with a field
/// classification \arg Field.
///
/// \param Accum - The accumulating classification. This should
/// always be either NoClass or the result of a previous merge
/// call. In addition, this should never be Memory (the caller
/// should just return Memory for the aggregate).
Class merge(Class Accum, Class Field) const;
/// classify - Determine the x86_64 register classes in which the
/// given type T should be passed.
///
/// \param Lo - The classification for the parts of the type
/// residing in the low word of the containing object.
///
/// \param Hi - The classification for the parts of the type
/// residing in the high word of the containing object.
///
/// \param OffsetBase - The bit offset of this type in the
/// containing object. Some parameters are classified different
/// depending on whether they straddle an eightbyte boundary.
///
/// If a word is unused its result will be NoClass; if a type should
/// be passed in Memory then at least the classification of \arg Lo
/// will be Memory.
///
/// The \arg Lo class will be NoClass iff the argument is ignored.
///
/// If the \arg Lo class is ComplexX87, then the \arg Hi class will
/// also be ComplexX87.
void classify(QualType T, ASTContext &Context, uint64_t OffsetBase,
Class &Lo, Class &Hi) const;
/// getCoerceResult - Given a source type \arg Ty and an LLVM type
/// to coerce to, chose the best way to pass Ty in the same place
/// that \arg CoerceTo would be passed, but while keeping the
/// emitted code as simple as possible.
///
/// FIXME: Note, this should be cleaned up to just take an
/// enumeration of all the ways we might want to pass things,
/// instead of constructing an LLVM type. This makes this code more
/// explicit, and it makes it clearer that we are also doing this
/// for correctness in the case of passing scalar types.
ABIArgInfo getCoerceResult(QualType Ty,
const llvm::Type *CoerceTo,
ASTContext &Context) const;
ABIArgInfo classifyReturnType(QualType RetTy,
ASTContext &Context) const;
ABIArgInfo classifyArgumentType(QualType Ty,
ASTContext &Context,
unsigned &neededInt,
unsigned &neededSSE) const;
public:
virtual void computeInfo(CGFunctionInfo &FI, ASTContext &Context) const;
virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
CodeGenFunction &CGF) const;
};
}
X86_64ABIInfo::Class X86_64ABIInfo::merge(Class Accum,
Class Field) const {
// AMD64-ABI 3.2.3p2: Rule 4. Each field of an object is
// classified recursively so that always two fields are
// considered. The resulting class is calculated according to
// the classes of the fields in the eightbyte:
//
// (a) If both classes are equal, this is the resulting class.
//
// (b) If one of the classes is NO_CLASS, the resulting class is
// the other class.
//
// (c) If one of the classes is MEMORY, the result is the MEMORY
// class.
//
// (d) If one of the classes is INTEGER, the result is the
// INTEGER.
//
// (e) If one of the classes is X87, X87UP, COMPLEX_X87 class,
// MEMORY is used as class.
//
// (f) Otherwise class SSE is used.
assert((Accum == NoClass || Accum == Integer ||
Accum == SSE || Accum == SSEUp) &&
"Invalid accumulated classification during merge.");
if (Accum == Field || Field == NoClass)
return Accum;
else if (Field == Memory)
return Memory;
else if (Accum == NoClass)
return Field;
else if (Accum == Integer || Field == Integer)
return Integer;
else if (Field == X87 || Field == X87Up || Field == ComplexX87)
return Memory;
else
return SSE;
}
void X86_64ABIInfo::classify(QualType Ty,
ASTContext &Context,
uint64_t OffsetBase,
Class &Lo, Class &Hi) const {
// FIXME: This code can be simplified by introducing a simple value
// class for Class pairs with appropriate constructor methods for
// the various situations.
// FIXME: Some of the split computations are wrong; unaligned
// vectors shouldn't be passed in registers for example, so there is
// no chance they can straddle an eightbyte. Verify & simplify.
Lo = Hi = NoClass;
Class &Current = OffsetBase < 64 ? Lo : Hi;
Current = Memory;
if (const BuiltinType *BT = Ty->getAsBuiltinType()) {
BuiltinType::Kind k = BT->getKind();
if (k == BuiltinType::Void) {
Current = NoClass;
} else if (k >= BuiltinType::Bool && k <= BuiltinType::LongLong) {
Current = Integer;
} else if (k == BuiltinType::Float || k == BuiltinType::Double) {
Current = SSE;
} else if (k == BuiltinType::LongDouble) {
Lo = X87;
Hi = X87Up;
}
// FIXME: _Decimal32 and _Decimal64 are SSE.
// FIXME: _float128 and _Decimal128 are (SSE, SSEUp).
// FIXME: __int128 is (Integer, Integer).
} else if (const EnumType *ET = Ty->getAsEnumType()) {
// Classify the underlying integer type.
classify(ET->getDecl()->getIntegerType(), Context, OffsetBase, Lo, Hi);
} else if (Ty->hasPointerRepresentation()) {
Current = Integer;
} else if (const VectorType *VT = Ty->getAsVectorType()) {
uint64_t Size = Context.getTypeSize(VT);
if (Size == 32) {
// gcc passes all <4 x char>, <2 x short>, <1 x int>, <1 x
// float> as integer.
Current = Integer;
// If this type crosses an eightbyte boundary, it should be
// split.
uint64_t EB_Real = (OffsetBase) / 64;
uint64_t EB_Imag = (OffsetBase + Size - 1) / 64;
if (EB_Real != EB_Imag)
Hi = Lo;
} else if (Size == 64) {
// gcc passes <1 x double> in memory. :(
if (VT->getElementType()->isSpecificBuiltinType(BuiltinType::Double))
return;
// gcc passes <1 x long long> as INTEGER.
if (VT->getElementType()->isSpecificBuiltinType(BuiltinType::LongLong))
Current = Integer;
else
Current = SSE;
// If this type crosses an eightbyte boundary, it should be
// split.
if (OffsetBase && OffsetBase != 64)
Hi = Lo;
} else if (Size == 128) {
Lo = SSE;
Hi = SSEUp;
}
} else if (const ComplexType *CT = Ty->getAsComplexType()) {
QualType ET = Context.getCanonicalType(CT->getElementType());
uint64_t Size = Context.getTypeSize(Ty);
if (ET->isIntegralType()) {
if (Size <= 64)
Current = Integer;
else if (Size <= 128)
Lo = Hi = Integer;
} else if (ET == Context.FloatTy)
Current = SSE;
else if (ET == Context.DoubleTy)
Lo = Hi = SSE;
else if (ET == Context.LongDoubleTy)
Current = ComplexX87;
// If this complex type crosses an eightbyte boundary then it
// should be split.
uint64_t EB_Real = (OffsetBase) / 64;
uint64_t EB_Imag = (OffsetBase + Context.getTypeSize(ET)) / 64;
if (Hi == NoClass && EB_Real != EB_Imag)
Hi = Lo;
} else if (const ConstantArrayType *AT = Context.getAsConstantArrayType(Ty)) {
// Arrays are treated like structures.
uint64_t Size = Context.getTypeSize(Ty);
// AMD64-ABI 3.2.3p2: Rule 1. If the size of an object is larger
// than two eightbytes, ..., it has class MEMORY.
if (Size > 128)
return;
// AMD64-ABI 3.2.3p2: Rule 1. If ..., or it contains unaligned
// fields, it has class MEMORY.
//
// Only need to check alignment of array base.
if (OffsetBase % Context.getTypeAlign(AT->getElementType()))
return;
// Otherwise implement simplified merge. We could be smarter about
// this, but it isn't worth it and would be harder to verify.
Current = NoClass;
uint64_t EltSize = Context.getTypeSize(AT->getElementType());
uint64_t ArraySize = AT->getSize().getZExtValue();
for (uint64_t i=0, Offset=OffsetBase; i<ArraySize; ++i, Offset += EltSize) {
Class FieldLo, FieldHi;
classify(AT->getElementType(), Context, Offset, FieldLo, FieldHi);
Lo = merge(Lo, FieldLo);
Hi = merge(Hi, FieldHi);
if (Lo == Memory || Hi == Memory)
break;
}
// Do post merger cleanup (see below). Only case we worry about is Memory.
if (Hi == Memory)
Lo = Memory;
assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp array classification.");
} else if (const RecordType *RT = Ty->getAsRecordType()) {
uint64_t Size = Context.getTypeSize(Ty);
// AMD64-ABI 3.2.3p2: Rule 1. If the size of an object is larger
// than two eightbytes, ..., it has class MEMORY.
if (Size > 128)
return;
const RecordDecl *RD = RT->getDecl();
// Assume variable sized types are passed in memory.
if (RD->hasFlexibleArrayMember())
return;
const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
// Reset Lo class, this will be recomputed.
Current = NoClass;
unsigned idx = 0;
for (RecordDecl::field_iterator i = RD->field_begin(),
e = RD->field_end(); i != e; ++i, ++idx) {
uint64_t Offset = OffsetBase + Layout.getFieldOffset(idx);
bool BitField = i->isBitField();
// AMD64-ABI 3.2.3p2: Rule 1. If ..., or it contains unaligned
// fields, it has class MEMORY.
//
// Note, skip this test for bitfields, see below.
if (!BitField && Offset % Context.getTypeAlign(i->getType())) {
Lo = Memory;
return;
}
// Classify this field.
//
// AMD64-ABI 3.2.3p2: Rule 3. If the size of the aggregate
// exceeds a single eightbyte, each is classified
// separately. Each eightbyte gets initialized to class
// NO_CLASS.
Class FieldLo, FieldHi;
// Bitfields require special handling, they do not force the
// structure to be passed in memory even if unaligned, and
// therefore they can straddle an eightbyte.
if (BitField) {
uint64_t Offset = OffsetBase + Layout.getFieldOffset(idx);
uint64_t Size =
i->getBitWidth()->getIntegerConstantExprValue(Context).getZExtValue();
uint64_t EB_Lo = Offset / 64;
uint64_t EB_Hi = (Offset + Size - 1) / 64;
FieldLo = FieldHi = NoClass;
if (EB_Lo) {
assert(EB_Hi == EB_Lo && "Invalid classification, type > 16 bytes.");
FieldLo = NoClass;
FieldHi = Integer;
} else {
FieldLo = Integer;
FieldHi = EB_Hi ? Integer : NoClass;
}
} else
classify(i->getType(), Context, Offset, FieldLo, FieldHi);
Lo = merge(Lo, FieldLo);
Hi = merge(Hi, FieldHi);
if (Lo == Memory || Hi == Memory)
break;
}
// AMD64-ABI 3.2.3p2: Rule 5. Then a post merger cleanup is done:
//
// (a) If one of the classes is MEMORY, the whole argument is
// passed in memory.
//
// (b) If SSEUP is not preceeded by SSE, it is converted to SSE.
// The first of these conditions is guaranteed by how we implement
// the merge (just bail).
//
// The second condition occurs in the case of unions; for example
// union { _Complex double; unsigned; }.
if (Hi == Memory)
Lo = Memory;
if (Hi == SSEUp && Lo != SSE)
Hi = SSE;
}
}
ABIArgInfo X86_64ABIInfo::getCoerceResult(QualType Ty,
const llvm::Type *CoerceTo,
ASTContext &Context) const {
if (CoerceTo == llvm::Type::Int64Ty) {
// Integer and pointer types will end up in a general purpose
// register.
if (Ty->isIntegralType() || Ty->isPointerType())
return ABIArgInfo::getDirect();
} else if (CoerceTo == llvm::Type::DoubleTy) {
// FIXME: It would probably be better to make CGFunctionInfo only
// map using canonical types than to canonize here.
QualType CTy = Context.getCanonicalType(Ty);
// Float and double end up in a single SSE reg.
if (CTy == Context.FloatTy || CTy == Context.DoubleTy)
return ABIArgInfo::getDirect();
}
return ABIArgInfo::getCoerce(CoerceTo);
}
ABIArgInfo X86_64ABIInfo::classifyReturnType(QualType RetTy,
ASTContext &Context) const {
// AMD64-ABI 3.2.3p4: Rule 1. Classify the return type with the
// classification algorithm.
X86_64ABIInfo::Class Lo, Hi;
classify(RetTy, Context, 0, Lo, Hi);
// Check some invariants.
assert((Hi != Memory || Lo == Memory) && "Invalid memory classification.");
assert((Lo != NoClass || Hi == NoClass) && "Invalid null classification.");
assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp classification.");
const llvm::Type *ResType = 0;
switch (Lo) {
case NoClass:
return ABIArgInfo::getIgnore();
case SSEUp:
case X87Up:
assert(0 && "Invalid classification for lo word.");
// AMD64-ABI 3.2.3p4: Rule 2. Types of class memory are returned via
// hidden argument.
case Memory:
return ABIArgInfo::getIndirect(0);
// AMD64-ABI 3.2.3p4: Rule 3. If the class is INTEGER, the next
// available register of the sequence %rax, %rdx is used.
case Integer:
ResType = llvm::Type::Int64Ty; break;
// AMD64-ABI 3.2.3p4: Rule 4. If the class is SSE, the next
// available SSE register of the sequence %xmm0, %xmm1 is used.
case SSE:
ResType = llvm::Type::DoubleTy; break;
// AMD64-ABI 3.2.3p4: Rule 6. If the class is X87, the value is
// returned on the X87 stack in %st0 as 80-bit x87 number.
case X87:
ResType = llvm::Type::X86_FP80Ty; break;
// AMD64-ABI 3.2.3p4: Rule 8. If the class is COMPLEX_X87, the real
// part of the value is returned in %st0 and the imaginary part in
// %st1.
case ComplexX87:
assert(Hi == ComplexX87 && "Unexpected ComplexX87 classification.");
ResType = llvm::StructType::get(llvm::Type::X86_FP80Ty,
llvm::Type::X86_FP80Ty,
NULL);
break;
}
switch (Hi) {
// Memory was handled previously and X87 should
// never occur as a hi class.
case Memory:
case X87:
assert(0 && "Invalid classification for hi word.");
case ComplexX87: // Previously handled.
case NoClass: break;
case Integer:
ResType = llvm::StructType::get(ResType, llvm::Type::Int64Ty, NULL);
break;
case SSE:
ResType = llvm::StructType::get(ResType, llvm::Type::DoubleTy, NULL);
break;
// AMD64-ABI 3.2.3p4: Rule 5. If the class is SSEUP, the eightbyte
// is passed in the upper half of the last used SSE register.
//
// SSEUP should always be preceeded by SSE, just widen.
case SSEUp:
assert(Lo == SSE && "Unexpected SSEUp classification.");
ResType = llvm::VectorType::get(llvm::Type::DoubleTy, 2);
break;
// AMD64-ABI 3.2.3p4: Rule 7. If the class is X87UP, the value is
// returned together with the previous X87 value in %st0.
//
// X87UP should always be preceeded by X87, so we don't need to do
// anything here.
case X87Up:
assert(Lo == X87 && "Unexpected X87Up classification.");
break;
}
return getCoerceResult(RetTy, ResType, Context);
}
ABIArgInfo X86_64ABIInfo::classifyArgumentType(QualType Ty, ASTContext &Context,
unsigned &neededInt,
unsigned &neededSSE) const {
X86_64ABIInfo::Class Lo, Hi;
classify(Ty, Context, 0, Lo, Hi);
// Check some invariants.
// FIXME: Enforce these by construction.
assert((Hi != Memory || Lo == Memory) && "Invalid memory classification.");
assert((Lo != NoClass || Hi == NoClass) && "Invalid null classification.");
assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp classification.");
neededInt = 0;
neededSSE = 0;
const llvm::Type *ResType = 0;
switch (Lo) {
case NoClass:
return ABIArgInfo::getIgnore();
// AMD64-ABI 3.2.3p3: Rule 1. If the class is MEMORY, pass the argument
// on the stack.
case Memory:
// AMD64-ABI 3.2.3p3: Rule 5. If the class is X87, X87UP or
// COMPLEX_X87, it is passed in memory.
case X87:
case ComplexX87:
return ABIArgInfo::getIndirect(0);
case SSEUp:
case X87Up:
assert(0 && "Invalid classification for lo word.");
// AMD64-ABI 3.2.3p3: Rule 2. If the class is INTEGER, the next
// available register of the sequence %rdi, %rsi, %rdx, %rcx, %r8
// and %r9 is used.
case Integer:
++neededInt;
ResType = llvm::Type::Int64Ty;
break;
// AMD64-ABI 3.2.3p3: Rule 3. If the class is SSE, the next
// available SSE register is used, the registers are taken in the
// order from %xmm0 to %xmm7.
case SSE:
++neededSSE;
ResType = llvm::Type::DoubleTy;
break;
}
switch (Hi) {
// Memory was handled previously, ComplexX87 and X87 should
// never occur as hi classes, and X87Up must be preceed by X87,
// which is passed in memory.
case Memory:
case X87:
case X87Up:
case ComplexX87:
assert(0 && "Invalid classification for hi word.");
case NoClass: break;
case Integer:
ResType = llvm::StructType::get(ResType, llvm::Type::Int64Ty, NULL);
++neededInt;
break;
case SSE:
ResType = llvm::StructType::get(ResType, llvm::Type::DoubleTy, NULL);
++neededSSE;
break;
// AMD64-ABI 3.2.3p3: Rule 4. If the class is SSEUP, the
// eightbyte is passed in the upper half of the last used SSE
// register.
case SSEUp:
assert(Lo == SSE && "Unexpected SSEUp classification.");
ResType = llvm::VectorType::get(llvm::Type::DoubleTy, 2);
break;
}
return getCoerceResult(Ty, ResType, Context);
}
void X86_64ABIInfo::computeInfo(CGFunctionInfo &FI, ASTContext &Context) const {
FI.getReturnInfo() = classifyReturnType(FI.getReturnType(), Context);
// Keep track of the number of assigned registers.
unsigned freeIntRegs = 6, freeSSERegs = 8;
// AMD64-ABI 3.2.3p3: Once arguments are classified, the registers
// get assigned (in left-to-right order) for passing as follows...
for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
it != ie; ++it) {
unsigned neededInt, neededSSE;
it->info = classifyArgumentType(it->type, Context, neededInt, neededSSE);
// AMD64-ABI 3.2.3p3: If there are no registers available for any
// eightbyte of an argument, the whole argument is passed on the
// stack. If registers have already been assigned for some
// eightbytes of such an argument, the assignments get reverted.
if (freeIntRegs >= neededInt && freeSSERegs >= neededSSE) {
freeIntRegs -= neededInt;
freeSSERegs -= neededSSE;
} else {
it->info = ABIArgInfo::getIndirect(0);
}
}
}
static llvm::Value *EmitVAArgFromMemory(llvm::Value *VAListAddr,
QualType Ty,
CodeGenFunction &CGF) {
llvm::Value *overflow_arg_area_p =
CGF.Builder.CreateStructGEP(VAListAddr, 2, "overflow_arg_area_p");
llvm::Value *overflow_arg_area =
CGF.Builder.CreateLoad(overflow_arg_area_p, "overflow_arg_area");
// AMD64-ABI 3.5.7p5: Step 7. Align l->overflow_arg_area upwards to a 16
// byte boundary if alignment needed by type exceeds 8 byte boundary.
uint64_t Align = CGF.getContext().getTypeAlign(Ty) / 8;
if (Align > 8) {
// Note that we follow the ABI & gcc here, even though the type
// could in theory have an alignment greater than 16. This case
// shouldn't ever matter in practice.
// overflow_arg_area = (overflow_arg_area + 15) & ~15;
llvm::Value *Offset = llvm::ConstantInt::get(llvm::Type::Int32Ty, 15);
overflow_arg_area = CGF.Builder.CreateGEP(overflow_arg_area, Offset);
llvm::Value *AsInt = CGF.Builder.CreatePtrToInt(overflow_arg_area,
llvm::Type::Int64Ty);
llvm::Value *Mask = llvm::ConstantInt::get(llvm::Type::Int64Ty, ~15LL);
overflow_arg_area =
CGF.Builder.CreateIntToPtr(CGF.Builder.CreateAnd(AsInt, Mask),
overflow_arg_area->getType(),
"overflow_arg_area.align");
}
// AMD64-ABI 3.5.7p5: Step 8. Fetch type from l->overflow_arg_area.
const llvm::Type *LTy = CGF.ConvertTypeForMem(Ty);
llvm::Value *Res =
CGF.Builder.CreateBitCast(overflow_arg_area,
llvm::PointerType::getUnqual(LTy));
// AMD64-ABI 3.5.7p5: Step 9. Set l->overflow_arg_area to:
// l->overflow_arg_area + sizeof(type).
// AMD64-ABI 3.5.7p5: Step 10. Align l->overflow_arg_area upwards to
// an 8 byte boundary.
uint64_t SizeInBytes = (CGF.getContext().getTypeSize(Ty) + 7) / 8;
llvm::Value *Offset = llvm::ConstantInt::get(llvm::Type::Int32Ty,
(SizeInBytes + 7) & ~7);
overflow_arg_area = CGF.Builder.CreateGEP(overflow_arg_area, Offset,
"overflow_arg_area.next");
CGF.Builder.CreateStore(overflow_arg_area, overflow_arg_area_p);
// AMD64-ABI 3.5.7p5: Step 11. Return the fetched type.
return Res;
}
llvm::Value *X86_64ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
CodeGenFunction &CGF) const {
// Assume that va_list type is correct; should be pointer to LLVM type:
// struct {
// i32 gp_offset;
// i32 fp_offset;
// i8* overflow_arg_area;
// i8* reg_save_area;
// };
unsigned neededInt, neededSSE;
ABIArgInfo AI = classifyArgumentType(Ty, CGF.getContext(),
neededInt, neededSSE);
// AMD64-ABI 3.5.7p5: Step 1. Determine whether type may be passed
// in the registers. If not go to step 7.
if (!neededInt && !neededSSE)
return EmitVAArgFromMemory(VAListAddr, Ty, CGF);
// AMD64-ABI 3.5.7p5: Step 2. Compute num_gp to hold the number of
// general purpose registers needed to pass type and num_fp to hold
// the number of floating point registers needed.
// AMD64-ABI 3.5.7p5: Step 3. Verify whether arguments fit into
// registers. In the case: l->gp_offset > 48 - num_gp * 8 or
// l->fp_offset > 304 - num_fp * 16 go to step 7.
//
// NOTE: 304 is a typo, there are (6 * 8 + 8 * 16) = 176 bytes of
// register save space).
llvm::Value *InRegs = 0;
llvm::Value *gp_offset_p = 0, *gp_offset = 0;
llvm::Value *fp_offset_p = 0, *fp_offset = 0;
if (neededInt) {
gp_offset_p = CGF.Builder.CreateStructGEP(VAListAddr, 0, "gp_offset_p");
gp_offset = CGF.Builder.CreateLoad(gp_offset_p, "gp_offset");
InRegs =
CGF.Builder.CreateICmpULE(gp_offset,
llvm::ConstantInt::get(llvm::Type::Int32Ty,
48 - neededInt * 8),
"fits_in_gp");
}
if (neededSSE) {
fp_offset_p = CGF.Builder.CreateStructGEP(VAListAddr, 1, "fp_offset_p");
fp_offset = CGF.Builder.CreateLoad(fp_offset_p, "fp_offset");
llvm::Value *FitsInFP =
CGF.Builder.CreateICmpULE(fp_offset,
llvm::ConstantInt::get(llvm::Type::Int32Ty,
176 - neededSSE * 16),
"fits_in_fp");
InRegs = InRegs ? CGF.Builder.CreateAnd(InRegs, FitsInFP) : FitsInFP;
}
llvm::BasicBlock *InRegBlock = CGF.createBasicBlock("vaarg.in_reg");
llvm::BasicBlock *InMemBlock = CGF.createBasicBlock("vaarg.in_mem");
llvm::BasicBlock *ContBlock = CGF.createBasicBlock("vaarg.end");
CGF.Builder.CreateCondBr(InRegs, InRegBlock, InMemBlock);
// Emit code to load the value if it was passed in registers.
CGF.EmitBlock(InRegBlock);
// AMD64-ABI 3.5.7p5: Step 4. Fetch type from l->reg_save_area with
// an offset of l->gp_offset and/or l->fp_offset. This may require
// copying to a temporary location in case the parameter is passed
// in different register classes or requires an alignment greater
// than 8 for general purpose registers and 16 for XMM registers.
//
// FIXME: This really results in shameful code when we end up
// needing to collect arguments from different places; often what
// should result in a simple assembling of a structure from
// scattered addresses has many more loads than necessary. Can we
// clean this up?
const llvm::Type *LTy = CGF.ConvertTypeForMem(Ty);
llvm::Value *RegAddr =
CGF.Builder.CreateLoad(CGF.Builder.CreateStructGEP(VAListAddr, 3),
"reg_save_area");
if (neededInt && neededSSE) {
// FIXME: Cleanup.
assert(AI.isCoerce() && "Unexpected ABI info for mixed regs");
const llvm::StructType *ST = cast<llvm::StructType>(AI.getCoerceToType());
llvm::Value *Tmp = CGF.CreateTempAlloca(ST);
assert(ST->getNumElements() == 2 && "Unexpected ABI info for mixed regs");
const llvm::Type *TyLo = ST->getElementType(0);
const llvm::Type *TyHi = ST->getElementType(1);
assert((TyLo->isFloatingPoint() ^ TyHi->isFloatingPoint()) &&
"Unexpected ABI info for mixed regs");
const llvm::Type *PTyLo = llvm::PointerType::getUnqual(TyLo);
const llvm::Type *PTyHi = llvm::PointerType::getUnqual(TyHi);
llvm::Value *GPAddr = CGF.Builder.CreateGEP(RegAddr, gp_offset);
llvm::Value *FPAddr = CGF.Builder.CreateGEP(RegAddr, fp_offset);
llvm::Value *RegLoAddr = TyLo->isFloatingPoint() ? FPAddr : GPAddr;
llvm::Value *RegHiAddr = TyLo->isFloatingPoint() ? GPAddr : FPAddr;
llvm::Value *V =
CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegLoAddr, PTyLo));
CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 0));
V = CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegHiAddr, PTyHi));
CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 1));
RegAddr = CGF.Builder.CreateBitCast(Tmp, llvm::PointerType::getUnqual(LTy));
} else if (neededInt) {
RegAddr = CGF.Builder.CreateGEP(RegAddr, gp_offset);
RegAddr = CGF.Builder.CreateBitCast(RegAddr,
llvm::PointerType::getUnqual(LTy));
} else {
if (neededSSE == 1) {
RegAddr = CGF.Builder.CreateGEP(RegAddr, fp_offset);
RegAddr = CGF.Builder.CreateBitCast(RegAddr,
llvm::PointerType::getUnqual(LTy));
} else {
assert(neededSSE == 2 && "Invalid number of needed registers!");
// SSE registers are spaced 16 bytes apart in the register save
// area, we need to collect the two eightbytes together.
llvm::Value *RegAddrLo = CGF.Builder.CreateGEP(RegAddr, fp_offset);
llvm::Value *RegAddrHi =
CGF.Builder.CreateGEP(RegAddrLo,
llvm::ConstantInt::get(llvm::Type::Int32Ty, 16));
const llvm::Type *DblPtrTy =
llvm::PointerType::getUnqual(llvm::Type::DoubleTy);
const llvm::StructType *ST = llvm::StructType::get(llvm::Type::DoubleTy,
llvm::Type::DoubleTy,
NULL);
llvm::Value *V, *Tmp = CGF.CreateTempAlloca(ST);
V = CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegAddrLo,
DblPtrTy));
CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 0));
V = CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegAddrHi,
DblPtrTy));
CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 1));
RegAddr = CGF.Builder.CreateBitCast(Tmp,
llvm::PointerType::getUnqual(LTy));
}
}
// AMD64-ABI 3.5.7p5: Step 5. Set:
// l->gp_offset = l->gp_offset + num_gp * 8
// l->fp_offset = l->fp_offset + num_fp * 16.
if (neededInt) {
llvm::Value *Offset = llvm::ConstantInt::get(llvm::Type::Int32Ty,
neededInt * 8);
CGF.Builder.CreateStore(CGF.Builder.CreateAdd(gp_offset, Offset),
gp_offset_p);
}
if (neededSSE) {
llvm::Value *Offset = llvm::ConstantInt::get(llvm::Type::Int32Ty,
neededSSE * 16);
CGF.Builder.CreateStore(CGF.Builder.CreateAdd(fp_offset, Offset),
fp_offset_p);
}
CGF.EmitBranch(ContBlock);
// Emit code to load the value if it was passed in memory.
CGF.EmitBlock(InMemBlock);
llvm::Value *MemAddr = EmitVAArgFromMemory(VAListAddr, Ty, CGF);
// Return the appropriate result.
CGF.EmitBlock(ContBlock);
llvm::PHINode *ResAddr = CGF.Builder.CreatePHI(RegAddr->getType(),
"vaarg.addr");
ResAddr->reserveOperandSpace(2);
ResAddr->addIncoming(RegAddr, InRegBlock);
ResAddr->addIncoming(MemAddr, InMemBlock);
return ResAddr;
}
ABIArgInfo DefaultABIInfo::classifyReturnType(QualType RetTy,
ASTContext &Context) const {
if (RetTy->isVoidType()) {
return ABIArgInfo::getIgnore();
} else if (CodeGenFunction::hasAggregateLLVMType(RetTy)) {
return ABIArgInfo::getIndirect(0);
} else {
return ABIArgInfo::getDirect();
}
}
ABIArgInfo DefaultABIInfo::classifyArgumentType(QualType Ty,
ASTContext &Context) const {
if (CodeGenFunction::hasAggregateLLVMType(Ty)) {
return ABIArgInfo::getIndirect(0);
} else {
return ABIArgInfo::getDirect();
}
}
llvm::Value *DefaultABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
CodeGenFunction &CGF) const {
return 0;
}
const ABIInfo &CodeGenTypes::getABIInfo() const {
if (TheABIInfo)
return *TheABIInfo;
// For now we just cache this in the CodeGenTypes and don't bother
// to free it.
const char *TargetPrefix = getContext().Target.getTargetPrefix();
if (strcmp(TargetPrefix, "x86") == 0) {
switch (getContext().Target.getPointerWidth(0)) {
case 32:
return *(TheABIInfo = new X86_32ABIInfo());
case 64:
return *(TheABIInfo = new X86_64ABIInfo());
}
}
return *(TheABIInfo = new DefaultABIInfo);
}
/***/
CGFunctionInfo::CGFunctionInfo(QualType ResTy,
const llvm::SmallVector<QualType, 16> &ArgTys) {
NumArgs = ArgTys.size();
Args = new ArgInfo[1 + NumArgs];
Args[0].type = ResTy;
for (unsigned i = 0; i < NumArgs; ++i)
Args[1 + i].type = ArgTys[i];
}
/***/
void CodeGenTypes::GetExpandedTypes(QualType Ty,
std::vector<const llvm::Type*> &ArgTys) {
const RecordType *RT = Ty->getAsStructureType();
assert(RT && "Can only expand structure types.");
const RecordDecl *RD = RT->getDecl();
assert(!RD->hasFlexibleArrayMember() &&
"Cannot expand structure with flexible array.");
for (RecordDecl::field_iterator i = RD->field_begin(),
e = RD->field_end(); i != e; ++i) {
const FieldDecl *FD = *i;
assert(!FD->isBitField() &&
"Cannot expand structure with bit-field members.");
QualType FT = FD->getType();
if (CodeGenFunction::hasAggregateLLVMType(FT)) {
GetExpandedTypes(FT, ArgTys);
} else {
ArgTys.push_back(ConvertType(FT));
}
}
}
llvm::Function::arg_iterator
CodeGenFunction::ExpandTypeFromArgs(QualType Ty, LValue LV,
llvm::Function::arg_iterator AI) {
const RecordType *RT = Ty->getAsStructureType();
assert(RT && "Can only expand structure types.");
RecordDecl *RD = RT->getDecl();
assert(LV.isSimple() &&
"Unexpected non-simple lvalue during struct expansion.");
llvm::Value *Addr = LV.getAddress();
for (RecordDecl::field_iterator i = RD->field_begin(),
e = RD->field_end(); i != e; ++i) {
FieldDecl *FD = *i;
QualType FT = FD->getType();
// FIXME: What are the right qualifiers here?
LValue LV = EmitLValueForField(Addr, FD, false, 0);
if (CodeGenFunction::hasAggregateLLVMType(FT)) {
AI = ExpandTypeFromArgs(FT, LV, AI);
} else {
EmitStoreThroughLValue(RValue::get(AI), LV, FT);
++AI;
}
}
return AI;
}
void
CodeGenFunction::ExpandTypeToArgs(QualType Ty, RValue RV,
llvm::SmallVector<llvm::Value*, 16> &Args) {
const RecordType *RT = Ty->getAsStructureType();
assert(RT && "Can only expand structure types.");
RecordDecl *RD = RT->getDecl();
assert(RV.isAggregate() && "Unexpected rvalue during struct expansion");
llvm::Value *Addr = RV.getAggregateAddr();
for (RecordDecl::field_iterator i = RD->field_begin(),
e = RD->field_end(); i != e; ++i) {
FieldDecl *FD = *i;
QualType FT = FD->getType();
// FIXME: What are the right qualifiers here?
LValue LV = EmitLValueForField(Addr, FD, false, 0);
if (CodeGenFunction::hasAggregateLLVMType(FT)) {
ExpandTypeToArgs(FT, RValue::getAggregate(LV.getAddress()), Args);
} else {
RValue RV = EmitLoadOfLValue(LV, FT);
assert(RV.isScalar() &&
"Unexpected non-scalar rvalue during struct expansion.");
Args.push_back(RV.getScalarVal());
}
}
}
/// CreateCoercedLoad - Create a load from \arg SrcPtr interpreted as
/// a pointer to an object of type \arg Ty.
///
/// This safely handles the case when the src type is smaller than the
/// destination type; in this situation the values of bits which not
/// present in the src are undefined.
static llvm::Value *CreateCoercedLoad(llvm::Value *SrcPtr,
const llvm::Type *Ty,
CodeGenFunction &CGF) {
const llvm::Type *SrcTy =
cast<llvm::PointerType>(SrcPtr->getType())->getElementType();
uint64_t SrcSize = CGF.CGM.getTargetData().getTypePaddedSize(SrcTy);
uint64_t DstSize = CGF.CGM.getTargetData().getTypePaddedSize(Ty);
// If load is legal, just bitcast the src pointer.
if (SrcSize == DstSize) {
llvm::Value *Casted =
CGF.Builder.CreateBitCast(SrcPtr, llvm::PointerType::getUnqual(Ty));
llvm::LoadInst *Load = CGF.Builder.CreateLoad(Casted);
// FIXME: Use better alignment / avoid requiring aligned load.
Load->setAlignment(1);
return Load;
} else {
assert(SrcSize < DstSize && "Coercion is losing source bits!");
// Otherwise do coercion through memory. This is stupid, but
// simple.
llvm::Value *Tmp = CGF.CreateTempAlloca(Ty);
llvm::Value *Casted =
CGF.Builder.CreateBitCast(Tmp, llvm::PointerType::getUnqual(SrcTy));
llvm::StoreInst *Store =
CGF.Builder.CreateStore(CGF.Builder.CreateLoad(SrcPtr), Casted);
// FIXME: Use better alignment / avoid requiring aligned store.
Store->setAlignment(1);
return CGF.Builder.CreateLoad(Tmp);
}
}
/// CreateCoercedStore - Create a store to \arg DstPtr from \arg Src,
/// where the source and destination may have different types.
///
/// This safely handles the case when the src type is larger than the
/// destination type; the upper bits of the src will be lost.
static void CreateCoercedStore(llvm::Value *Src,
llvm::Value *DstPtr,
CodeGenFunction &CGF) {
const llvm::Type *SrcTy = Src->getType();
const llvm::Type *DstTy =
cast<llvm::PointerType>(DstPtr->getType())->getElementType();
uint64_t SrcSize = CGF.CGM.getTargetData().getTypePaddedSize(SrcTy);
uint64_t DstSize = CGF.CGM.getTargetData().getTypePaddedSize(DstTy);
// If store is legal, just bitcast the src pointer.
if (SrcSize == DstSize) {
llvm::Value *Casted =
CGF.Builder.CreateBitCast(DstPtr, llvm::PointerType::getUnqual(SrcTy));
// FIXME: Use better alignment / avoid requiring aligned store.
CGF.Builder.CreateStore(Src, Casted)->setAlignment(1);
} else {
assert(SrcSize > DstSize && "Coercion is missing bits!");
// Otherwise do coercion through memory. This is stupid, but
// simple.
llvm::Value *Tmp = CGF.CreateTempAlloca(SrcTy);
CGF.Builder.CreateStore(Src, Tmp);
llvm::Value *Casted =
CGF.Builder.CreateBitCast(Tmp, llvm::PointerType::getUnqual(DstTy));
llvm::LoadInst *Load = CGF.Builder.CreateLoad(Casted);
// FIXME: Use better alignment / avoid requiring aligned load.
Load->setAlignment(1);
CGF.Builder.CreateStore(Load, DstPtr);
}
}
/***/
bool CodeGenModule::ReturnTypeUsesSret(const CGFunctionInfo &FI) {
return FI.getReturnInfo().isIndirect();
}
const llvm::FunctionType *
CodeGenTypes::GetFunctionType(const CGFunctionInfo &FI, bool IsVariadic) {
std::vector<const llvm::Type*> ArgTys;
const llvm::Type *ResultType = 0;
QualType RetTy = FI.getReturnType();
const ABIArgInfo &RetAI = FI.getReturnInfo();
switch (RetAI.getKind()) {
case ABIArgInfo::Expand:
assert(0 && "Invalid ABI kind for return argument");
case ABIArgInfo::Direct:
ResultType = ConvertType(RetTy);
break;
case ABIArgInfo::Indirect: {
assert(!RetAI.getIndirectAlign() && "Align unused on indirect return.");
ResultType = llvm::Type::VoidTy;
const llvm::Type *STy = ConvertType(RetTy);
ArgTys.push_back(llvm::PointerType::get(STy, RetTy.getAddressSpace()));
break;
}
case ABIArgInfo::Ignore:
ResultType = llvm::Type::VoidTy;
break;
case ABIArgInfo::Coerce:
ResultType = RetAI.getCoerceToType();
break;
}
for (CGFunctionInfo::const_arg_iterator it = FI.arg_begin(),
ie = FI.arg_end(); it != ie; ++it) {
const ABIArgInfo &AI = it->info;
switch (AI.getKind()) {
case ABIArgInfo::Ignore:
break;
case ABIArgInfo::Coerce:
ArgTys.push_back(AI.getCoerceToType());
break;
case ABIArgInfo::Indirect: {
// indirect arguments are always on the stack, which is addr space #0.
const llvm::Type *LTy = ConvertTypeForMem(it->type);
ArgTys.push_back(llvm::PointerType::getUnqual(LTy));
break;
}
case ABIArgInfo::Direct:
ArgTys.push_back(ConvertType(it->type));
break;
case ABIArgInfo::Expand:
GetExpandedTypes(it->type, ArgTys);
break;
}
}
return llvm::FunctionType::get(ResultType, ArgTys, IsVariadic);
}
void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI,
const Decl *TargetDecl,
AttributeListType &PAL) {
unsigned FuncAttrs = 0;
unsigned RetAttrs = 0;
if (TargetDecl) {
if (TargetDecl->getAttr<NoThrowAttr>())
FuncAttrs |= llvm::Attribute::NoUnwind;
if (TargetDecl->getAttr<NoReturnAttr>())
FuncAttrs |= llvm::Attribute::NoReturn;
if (TargetDecl->getAttr<PureAttr>())
FuncAttrs |= llvm::Attribute::ReadOnly;
if (TargetDecl->getAttr<ConstAttr>())
FuncAttrs |= llvm::Attribute::ReadNone;
}
QualType RetTy = FI.getReturnType();
unsigned Index = 1;
const ABIArgInfo &RetAI = FI.getReturnInfo();
switch (RetAI.getKind()) {
case ABIArgInfo::Direct:
if (RetTy->isPromotableIntegerType()) {
if (RetTy->isSignedIntegerType()) {
RetAttrs |= llvm::Attribute::SExt;
} else if (RetTy->isUnsignedIntegerType()) {
RetAttrs |= llvm::Attribute::ZExt;
}
}
break;
case ABIArgInfo::Indirect:
PAL.push_back(llvm::AttributeWithIndex::get(Index,
llvm::Attribute::StructRet |
llvm::Attribute::NoAlias));
++Index;
break;
case ABIArgInfo::Ignore:
case ABIArgInfo::Coerce:
break;
case ABIArgInfo::Expand:
assert(0 && "Invalid ABI kind for return argument");
}
if (RetAttrs)
PAL.push_back(llvm::AttributeWithIndex::get(0, RetAttrs));
for (CGFunctionInfo::const_arg_iterator it = FI.arg_begin(),
ie = FI.arg_end(); it != ie; ++it) {
QualType ParamType = it->type;
const ABIArgInfo &AI = it->info;
unsigned Attributes = 0;
switch (AI.getKind()) {
case ABIArgInfo::Coerce:
break;
case ABIArgInfo::Indirect:
Attributes |= llvm::Attribute::ByVal;
Attributes |=
llvm::Attribute::constructAlignmentFromInt(AI.getIndirectAlign());
break;
case ABIArgInfo::Direct:
if (ParamType->isPromotableIntegerType()) {
if (ParamType->isSignedIntegerType()) {
Attributes |= llvm::Attribute::SExt;
} else if (ParamType->isUnsignedIntegerType()) {
Attributes |= llvm::Attribute::ZExt;
}
}
break;
case ABIArgInfo::Ignore:
// Skip increment, no matching LLVM parameter.
continue;
case ABIArgInfo::Expand: {
std::vector<const llvm::Type*> Tys;
// FIXME: This is rather inefficient. Do we ever actually need
// to do anything here? The result should be just reconstructed
// on the other side, so extension should be a non-issue.
getTypes().GetExpandedTypes(ParamType, Tys);
Index += Tys.size();
continue;
}
}
if (Attributes)
PAL.push_back(llvm::AttributeWithIndex::get(Index, Attributes));
++Index;
}
if (FuncAttrs)
PAL.push_back(llvm::AttributeWithIndex::get(~0, FuncAttrs));
}
void CodeGenFunction::EmitFunctionProlog(const CGFunctionInfo &FI,
llvm::Function *Fn,
const FunctionArgList &Args) {
// FIXME: We no longer need the types from FunctionArgList; lift up
// and simplify.
// Emit allocs for param decls. Give the LLVM Argument nodes names.
llvm::Function::arg_iterator AI = Fn->arg_begin();
// Name the struct return argument.
if (CGM.ReturnTypeUsesSret(FI)) {
AI->setName("agg.result");
++AI;
}
assert(FI.arg_size() == Args.size() &&
"Mismatch between function signature & arguments.");
CGFunctionInfo::const_arg_iterator info_it = FI.arg_begin();
for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end();
i != e; ++i, ++info_it) {
const VarDecl *Arg = i->first;
QualType Ty = info_it->type;
const ABIArgInfo &ArgI = info_it->info;
switch (ArgI.getKind()) {
case ABIArgInfo::Indirect: {
llvm::Value* V = AI;
if (hasAggregateLLVMType(Ty)) {
// Do nothing, aggregates and complex variables are accessed by
// reference.
} else {
// Load scalar value from indirect argument.
V = EmitLoadOfScalar(V, false, Ty);
if (!getContext().typesAreCompatible(Ty, Arg->getType())) {
// This must be a promotion, for something like
// "void a(x) short x; {..."
V = EmitScalarConversion(V, Ty, Arg->getType());
}
}
EmitParmDecl(*Arg, V);
break;
}
case ABIArgInfo::Direct: {
assert(AI != Fn->arg_end() && "Argument mismatch!");
llvm::Value* V = AI;
if (hasAggregateLLVMType(Ty)) {
// Create a temporary alloca to hold the argument; the rest of
// codegen expects to access aggregates & complex values by
// reference.
V = CreateTempAlloca(ConvertTypeForMem(Ty));
Builder.CreateStore(AI, V);
} else {
if (!getContext().typesAreCompatible(Ty, Arg->getType())) {
// This must be a promotion, for something like
// "void a(x) short x; {..."
V = EmitScalarConversion(V, Ty, Arg->getType());
}
}
EmitParmDecl(*Arg, V);
break;
}
case ABIArgInfo::Expand: {
// If this structure was expanded into multiple arguments then
// we need to create a temporary and reconstruct it from the
// arguments.
std::string Name = Arg->getNameAsString();
llvm::Value *Temp = CreateTempAlloca(ConvertTypeForMem(Ty),
(Name + ".addr").c_str());
// FIXME: What are the right qualifiers here?
llvm::Function::arg_iterator End =
ExpandTypeFromArgs(Ty, LValue::MakeAddr(Temp,0), AI);
EmitParmDecl(*Arg, Temp);
// Name the arguments used in expansion and increment AI.
unsigned Index = 0;
for (; AI != End; ++AI, ++Index)
AI->setName(Name + "." + llvm::utostr(Index));
continue;
}
case ABIArgInfo::Ignore:
// Initialize the local variable appropriately.
if (hasAggregateLLVMType(Ty)) {
EmitParmDecl(*Arg, CreateTempAlloca(ConvertTypeForMem(Ty)));
} else {
EmitParmDecl(*Arg, llvm::UndefValue::get(ConvertType(Arg->getType())));
}
// Skip increment, no matching LLVM parameter.
continue;
case ABIArgInfo::Coerce: {
assert(AI != Fn->arg_end() && "Argument mismatch!");
// FIXME: This is very wasteful; EmitParmDecl is just going to
// drop the result in a new alloca anyway, so we could just
// store into that directly if we broke the abstraction down
// more.
llvm::Value *V = CreateTempAlloca(ConvertTypeForMem(Ty), "coerce");
CreateCoercedStore(AI, V, *this);
// Match to what EmitParmDecl is expecting for this type.
if (!CodeGenFunction::hasAggregateLLVMType(Ty)) {
V = EmitLoadOfScalar(V, false, Ty);
if (!getContext().typesAreCompatible(Ty, Arg->getType())) {
// This must be a promotion, for something like
// "void a(x) short x; {..."
V = EmitScalarConversion(V, Ty, Arg->getType());
}
}
EmitParmDecl(*Arg, V);
break;
}
}
++AI;
}
assert(AI == Fn->arg_end() && "Argument mismatch!");
}
void CodeGenFunction::EmitFunctionEpilog(const CGFunctionInfo &FI,
llvm::Value *ReturnValue) {
llvm::Value *RV = 0;
// Functions with no result always return void.
if (ReturnValue) {
QualType RetTy = FI.getReturnType();
const ABIArgInfo &RetAI = FI.getReturnInfo();
switch (RetAI.getKind()) {
case ABIArgInfo::Indirect:
if (RetTy->isAnyComplexType()) {
ComplexPairTy RT = LoadComplexFromAddr(ReturnValue, false);
StoreComplexToAddr(RT, CurFn->arg_begin(), false);
} else if (CodeGenFunction::hasAggregateLLVMType(RetTy)) {
EmitAggregateCopy(CurFn->arg_begin(), ReturnValue, RetTy);
} else {
EmitStoreOfScalar(Builder.CreateLoad(ReturnValue), CurFn->arg_begin(),
false);
}
break;
case ABIArgInfo::Direct:
// The internal return value temp always will have
// pointer-to-return-type type.
RV = Builder.CreateLoad(ReturnValue);
break;
case ABIArgInfo::Ignore:
break;
case ABIArgInfo::Coerce:
RV = CreateCoercedLoad(ReturnValue, RetAI.getCoerceToType(), *this);
break;
case ABIArgInfo::Expand:
assert(0 && "Invalid ABI kind for return argument");
}
}
if (RV) {
Builder.CreateRet(RV);
} else {
Builder.CreateRetVoid();
}
}
RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
llvm::Value *Callee,
const CallArgList &CallArgs,
const Decl *TargetDecl) {
// FIXME: We no longer need the types from CallArgs; lift up and
// simplify.
llvm::SmallVector<llvm::Value*, 16> Args;
// Handle struct-return functions by passing a pointer to the
// location that we would like to return into.
QualType RetTy = CallInfo.getReturnType();
const ABIArgInfo &RetAI = CallInfo.getReturnInfo();
if (CGM.ReturnTypeUsesSret(CallInfo)) {
// Create a temporary alloca to hold the result of the call. :(
Args.push_back(CreateTempAlloca(ConvertTypeForMem(RetTy)));
}
assert(CallInfo.arg_size() == CallArgs.size() &&
"Mismatch between function signature & arguments.");
CGFunctionInfo::const_arg_iterator info_it = CallInfo.arg_begin();
for (CallArgList::const_iterator I = CallArgs.begin(), E = CallArgs.end();
I != E; ++I, ++info_it) {
const ABIArgInfo &ArgInfo = info_it->info;
RValue RV = I->first;
switch (ArgInfo.getKind()) {
case ABIArgInfo::Indirect:
if (RV.isScalar() || RV.isComplex()) {
// Make a temporary alloca to pass the argument.
Args.push_back(CreateTempAlloca(ConvertTypeForMem(I->second)));
if (RV.isScalar())
EmitStoreOfScalar(RV.getScalarVal(), Args.back(), false);
else
StoreComplexToAddr(RV.getComplexVal(), Args.back(), false);
} else {
Args.push_back(RV.getAggregateAddr());
}
break;
case ABIArgInfo::Direct:
if (RV.isScalar()) {
Args.push_back(RV.getScalarVal());
} else if (RV.isComplex()) {
llvm::Value *Tmp = llvm::UndefValue::get(ConvertType(I->second));
Tmp = Builder.CreateInsertValue(Tmp, RV.getComplexVal().first, 0);
Tmp = Builder.CreateInsertValue(Tmp, RV.getComplexVal().second, 1);
Args.push_back(Tmp);
} else {
Args.push_back(Builder.CreateLoad(RV.getAggregateAddr()));
}
break;
case ABIArgInfo::Ignore:
break;
case ABIArgInfo::Coerce: {
// FIXME: Avoid the conversion through memory if possible.
llvm::Value *SrcPtr;
if (RV.isScalar()) {
SrcPtr = CreateTempAlloca(ConvertTypeForMem(I->second), "coerce");
EmitStoreOfScalar(RV.getScalarVal(), SrcPtr, false);
} else if (RV.isComplex()) {
SrcPtr = CreateTempAlloca(ConvertTypeForMem(I->second), "coerce");
StoreComplexToAddr(RV.getComplexVal(), SrcPtr, false);
} else
SrcPtr = RV.getAggregateAddr();
Args.push_back(CreateCoercedLoad(SrcPtr, ArgInfo.getCoerceToType(),
*this));
break;
}
case ABIArgInfo::Expand:
ExpandTypeToArgs(I->second, RV, Args);
break;
}
}
llvm::BasicBlock *InvokeDest = getInvokeDest();
CodeGen::AttributeListType AttributeList;
CGM.ConstructAttributeList(CallInfo, TargetDecl, AttributeList);
llvm::AttrListPtr Attrs = llvm::AttrListPtr::get(AttributeList.begin(),
AttributeList.end());
llvm::Instruction *CI;
if (!InvokeDest || Attrs.getFnAttributes() & (llvm::Attribute::NoUnwind ||
llvm::Attribute::NoReturn)) {
llvm::CallInst *CallInstr =
Builder.CreateCall(Callee, &Args[0], &Args[0]+Args.size());
CI = CallInstr;
CallInstr->setAttributes(Attrs);
if (const llvm::Function *F = dyn_cast<llvm::Function>(Callee))
CallInstr->setCallingConv(F->getCallingConv());
// If the call doesn't return, finish the basic block and clear the
// insertion point; this allows the rest of IRgen to discard
// unreachable code.
if (CallInstr->doesNotReturn()) {
Builder.CreateUnreachable();
Builder.ClearInsertionPoint();
// FIXME: For now, emit a dummy basic block because expr
// emitters in generally are not ready to handle emitting
// expressions at unreachable points.
EnsureInsertPoint();
// Return a reasonable RValue.
return GetUndefRValue(RetTy);
}
} else {
llvm::BasicBlock *Cont = createBasicBlock("invoke.cont");
llvm::InvokeInst *InvokeInstr =
Builder.CreateInvoke(Callee, Cont, InvokeDest,
&Args[0], &Args[0]+Args.size());
CI = InvokeInstr;
InvokeInstr->setAttributes(Attrs);
if (const llvm::Function *F = dyn_cast<llvm::Function>(Callee))
InvokeInstr->setCallingConv(F->getCallingConv());
EmitBlock(Cont);
}
if (CI->getType() != llvm::Type::VoidTy)
CI->setName("call");
switch (RetAI.getKind()) {
case ABIArgInfo::Indirect:
if (RetTy->isAnyComplexType())
return RValue::getComplex(LoadComplexFromAddr(Args[0], false));
else if (CodeGenFunction::hasAggregateLLVMType(RetTy))
return RValue::getAggregate(Args[0]);
else
return RValue::get(EmitLoadOfScalar(Args[0], false, RetTy));
case ABIArgInfo::Direct:
if (RetTy->isAnyComplexType()) {
llvm::Value *Real = Builder.CreateExtractValue(CI, 0);
llvm::Value *Imag = Builder.CreateExtractValue(CI, 1);
return RValue::getComplex(std::make_pair(Real, Imag));
} else if (CodeGenFunction::hasAggregateLLVMType(RetTy)) {
llvm::Value *V = CreateTempAlloca(ConvertTypeForMem(RetTy), "agg.tmp");
Builder.CreateStore(CI, V);
return RValue::getAggregate(V);
} else
return RValue::get(CI);
case ABIArgInfo::Ignore:
// If we are ignoring an argument that had a result, make sure to
// construct the appropriate return value for our caller.
return GetUndefRValue(RetTy);
case ABIArgInfo::Coerce: {
// FIXME: Avoid the conversion through memory if possible.
llvm::Value *V = CreateTempAlloca(ConvertTypeForMem(RetTy), "coerce");
CreateCoercedStore(CI, V, *this);
if (RetTy->isAnyComplexType())
return RValue::getComplex(LoadComplexFromAddr(V, false));
else if (CodeGenFunction::hasAggregateLLVMType(RetTy))
return RValue::getAggregate(V);
else
return RValue::get(EmitLoadOfScalar(V, false, RetTy));
}
case ABIArgInfo::Expand:
assert(0 && "Invalid ABI kind for return argument");
}
assert(0 && "Unhandled ABIArgInfo::Kind");
return RValue::get(0);
}
/* VarArg handling */
llvm::Value *CodeGenFunction::EmitVAArg(llvm::Value *VAListAddr, QualType Ty) {
return CGM.getTypes().getABIInfo().EmitVAArg(VAListAddr, Ty, *this);
}
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