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llvm-project/clang/lib/CodeGen/CGExpr.cpp

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//===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This contains code to emit Expr nodes as LLVM code.
//
//===----------------------------------------------------------------------===//
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "CGCall.h"
#include "CGObjCRuntime.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "llvm/Target/TargetData.h"
using namespace clang;
using namespace CodeGen;
//===--------------------------------------------------------------------===//
// Miscellaneous Helper Methods
//===--------------------------------------------------------------------===//
/// CreateTempAlloca - This creates a alloca and inserts it into the entry
/// block.
llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(const llvm::Type *Ty,
const char *Name) {
return new llvm::AllocaInst(Ty, 0, Name, AllocaInsertPt);
}
/// EvaluateExprAsBool - Perform the usual unary conversions on the specified
/// expression and compare the result against zero, returning an Int1Ty value.
llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
QualType BoolTy = getContext().BoolTy;
if (!E->getType()->isAnyComplexType())
return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy);
return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(),BoolTy);
}
/// EmitAnyExpr - Emit code to compute the specified expression which can have
/// any type. The result is returned as an RValue struct. If this is an
/// aggregate expression, the aggloc/agglocvolatile arguments indicate where
/// the result should be returned.
RValue CodeGenFunction::EmitAnyExpr(const Expr *E, llvm::Value *AggLoc,
bool isAggLocVolatile) {
if (!hasAggregateLLVMType(E->getType()))
return RValue::get(EmitScalarExpr(E));
else if (E->getType()->isAnyComplexType())
return RValue::getComplex(EmitComplexExpr(E));
EmitAggExpr(E, AggLoc, isAggLocVolatile);
return RValue::getAggregate(AggLoc);
}
/// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result
/// will always be accessible even if no aggregate location is
/// provided.
RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E, llvm::Value *AggLoc,
bool isAggLocVolatile) {
if (!AggLoc && hasAggregateLLVMType(E->getType()) &&
!E->getType()->isAnyComplexType())
AggLoc = CreateTempAlloca(ConvertType(E->getType()), "agg.tmp");
return EmitAnyExpr(E, AggLoc, isAggLocVolatile);
}
/// getAccessedFieldNo - Given an encoded value and a result number, return
/// the input field number being accessed.
unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
const llvm::Constant *Elts) {
if (isa<llvm::ConstantAggregateZero>(Elts))
return 0;
return cast<llvm::ConstantInt>(Elts->getOperand(Idx))->getZExtValue();
}
//===----------------------------------------------------------------------===//
// LValue Expression Emission
//===----------------------------------------------------------------------===//
RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
if (Ty->isVoidType()) {
return RValue::get(0);
} else if (const ComplexType *CTy = Ty->getAsComplexType()) {
const llvm::Type *EltTy = ConvertType(CTy->getElementType());
llvm::Value *U = llvm::UndefValue::get(EltTy);
return RValue::getComplex(std::make_pair(U, U));
} else if (hasAggregateLLVMType(Ty)) {
const llvm::Type *LTy = llvm::PointerType::getUnqual(ConvertType(Ty));
return RValue::getAggregate(llvm::UndefValue::get(LTy));
} else {
return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
}
}
RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
const char *Name) {
ErrorUnsupported(E, Name);
return GetUndefRValue(E->getType());
}
LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
const char *Name) {
ErrorUnsupported(E, Name);
llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
return LValue::MakeAddr(llvm::UndefValue::get(Ty),
E->getType().getCVRQualifiers());
}
/// EmitLValue - Emit code to compute a designator that specifies the location
/// of the expression.
///
/// This can return one of two things: a simple address or a bitfield
/// reference. In either case, the LLVM Value* in the LValue structure is
/// guaranteed to be an LLVM pointer type.
///
/// If this returns a bitfield reference, nothing about the pointee type of
/// the LLVM value is known: For example, it may not be a pointer to an
/// integer.
///
/// If this returns a normal address, and if the lvalue's C type is fixed
/// size, this method guarantees that the returned pointer type will point to
/// an LLVM type of the same size of the lvalue's type. If the lvalue has a
/// variable length type, this is not possible.
///
LValue CodeGenFunction::EmitLValue(const Expr *E) {
switch (E->getStmtClass()) {
default: return EmitUnsupportedLValue(E, "l-value expression");
case Expr::BinaryOperatorClass:
return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
case Expr::CallExprClass:
case Expr::CXXOperatorCallExprClass:
return EmitCallExprLValue(cast<CallExpr>(E));
case Expr::VAArgExprClass:
return EmitVAArgExprLValue(cast<VAArgExpr>(E));
case Expr::DeclRefExprClass:
case Expr::QualifiedDeclRefExprClass:
return EmitDeclRefLValue(cast<DeclRefExpr>(E));
case Expr::ParenExprClass:return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
case Expr::PredefinedExprClass:
return EmitPredefinedLValue(cast<PredefinedExpr>(E));
case Expr::StringLiteralClass:
return EmitStringLiteralLValue(cast<StringLiteral>(E));
case Expr::CXXConditionDeclExprClass:
return EmitCXXConditionDeclLValue(cast<CXXConditionDeclExpr>(E));
case Expr::ObjCMessageExprClass:
return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
case Expr::ObjCIvarRefExprClass:
return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
case Expr::ObjCPropertyRefExprClass:
return EmitObjCPropertyRefLValue(cast<ObjCPropertyRefExpr>(E));
case Expr::ObjCKVCRefExprClass:
return EmitObjCKVCRefLValue(cast<ObjCKVCRefExpr>(E));
case Expr::ObjCSuperExprClass:
return EmitObjCSuperExpr(cast<ObjCSuperExpr>(E));
case Expr::UnaryOperatorClass:
return EmitUnaryOpLValue(cast<UnaryOperator>(E));
case Expr::ArraySubscriptExprClass:
return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
case Expr::ExtVectorElementExprClass:
return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
case Expr::MemberExprClass: return EmitMemberExpr(cast<MemberExpr>(E));
case Expr::CompoundLiteralExprClass:
return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
case Expr::ChooseExprClass:
// __builtin_choose_expr is the lvalue of the selected operand.
if (cast<ChooseExpr>(E)->isConditionTrue(getContext()))
return EmitLValue(cast<ChooseExpr>(E)->getLHS());
else
return EmitLValue(cast<ChooseExpr>(E)->getRHS());
}
}
llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
QualType Ty) {
llvm::Value *V = Builder.CreateLoad(Addr, Volatile, "tmp");
// Bool can have different representation in memory than in
// registers.
if (Ty->isBooleanType())
if (V->getType() != llvm::Type::Int1Ty)
V = Builder.CreateTrunc(V, llvm::Type::Int1Ty, "tobool");
return V;
}
void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
bool Volatile) {
// Handle stores of types which have different representations in
// memory and as LLVM values.
// FIXME: We shouldn't be this loose, we should only do this
// conversion when we have a type we know has a different memory
// representation (e.g., bool).
const llvm::Type *SrcTy = Value->getType();
const llvm::PointerType *DstPtr = cast<llvm::PointerType>(Addr->getType());
if (DstPtr->getElementType() != SrcTy) {
const llvm::Type *MemTy =
llvm::PointerType::get(SrcTy, DstPtr->getAddressSpace());
Addr = Builder.CreateBitCast(Addr, MemTy, "storetmp");
}
Builder.CreateStore(Value, Addr, Volatile);
}
/// EmitLoadOfLValue - Given an expression that represents a value lvalue,
/// this method emits the address of the lvalue, then loads the result as an
/// rvalue, returning the rvalue.
RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, QualType ExprType) {
if (LV.isObjCWeak()) {
// load of a __weak object.
llvm::Value *AddrWeakObj = LV.getAddress();
llvm::Value *read_weak = CGM.getObjCRuntime().EmitObjCWeakRead(*this,
AddrWeakObj);
return RValue::get(read_weak);
}
if (LV.isSimple()) {
llvm::Value *Ptr = LV.getAddress();
const llvm::Type *EltTy =
cast<llvm::PointerType>(Ptr->getType())->getElementType();
// Simple scalar l-value.
if (EltTy->isSingleValueType())
return RValue::get(EmitLoadOfScalar(Ptr, LV.isVolatileQualified(),
ExprType));
assert(ExprType->isFunctionType() && "Unknown scalar value");
return RValue::get(Ptr);
}
if (LV.isVectorElt()) {
llvm::Value *Vec = Builder.CreateLoad(LV.getVectorAddr(),
LV.isVolatileQualified(), "tmp");
return RValue::get(Builder.CreateExtractElement(Vec, LV.getVectorIdx(),
"vecext"));
}
// If this is a reference to a subset of the elements of a vector, either
// shuffle the input or extract/insert them as appropriate.
if (LV.isExtVectorElt())
return EmitLoadOfExtVectorElementLValue(LV, ExprType);
if (LV.isBitfield())
return EmitLoadOfBitfieldLValue(LV, ExprType);
if (LV.isPropertyRef())
return EmitLoadOfPropertyRefLValue(LV, ExprType);
if (LV.isKVCRef())
return EmitLoadOfKVCRefLValue(LV, ExprType);
assert(0 && "Unknown LValue type!");
//an invalid RValue, but the assert will
//ensure that this point is never reached
return RValue();
}
RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
QualType ExprType) {
unsigned StartBit = LV.getBitfieldStartBit();
unsigned BitfieldSize = LV.getBitfieldSize();
llvm::Value *Ptr = LV.getBitfieldAddr();
const llvm::Type *EltTy =
cast<llvm::PointerType>(Ptr->getType())->getElementType();
unsigned EltTySize = CGM.getTargetData().getTypeSizeInBits(EltTy);
// In some cases the bitfield may straddle two memory locations.
// Currently we load the entire bitfield, then do the magic to
// sign-extend it if necessary. This results in somewhat more code
// than necessary for the common case (one load), since two shifts
// accomplish both the masking and sign extension.
unsigned LowBits = std::min(BitfieldSize, EltTySize - StartBit);
llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "tmp");
// Shift to proper location.
if (StartBit)
Val = Builder.CreateLShr(Val, llvm::ConstantInt::get(EltTy, StartBit),
"bf.lo");
// Mask off unused bits.
llvm::Constant *LowMask =
llvm::ConstantInt::get(llvm::APInt::getLowBitsSet(EltTySize, LowBits));
Val = Builder.CreateAnd(Val, LowMask, "bf.lo.cleared");
// Fetch the high bits if necessary.
if (LowBits < BitfieldSize) {
unsigned HighBits = BitfieldSize - LowBits;
llvm::Value *HighPtr =
Builder.CreateGEP(Ptr, llvm::ConstantInt::get(llvm::Type::Int32Ty, 1),
"bf.ptr.hi");
llvm::Value *HighVal = Builder.CreateLoad(HighPtr,
LV.isVolatileQualified(),
"tmp");
// Mask off unused bits.
llvm::Constant *HighMask =
llvm::ConstantInt::get(llvm::APInt::getLowBitsSet(EltTySize, HighBits));
HighVal = Builder.CreateAnd(HighVal, HighMask, "bf.lo.cleared");
// Shift to proper location and or in to bitfield value.
HighVal = Builder.CreateShl(HighVal,
llvm::ConstantInt::get(EltTy, LowBits));
Val = Builder.CreateOr(Val, HighVal, "bf.val");
}
// Sign extend if necessary.
if (LV.isBitfieldSigned()) {
llvm::Value *ExtraBits = llvm::ConstantInt::get(EltTy,
EltTySize - BitfieldSize);
Val = Builder.CreateAShr(Builder.CreateShl(Val, ExtraBits),
ExtraBits, "bf.val.sext");
}
// The bitfield type and the normal type differ when the storage sizes
// differ (currently just _Bool).
Val = Builder.CreateIntCast(Val, ConvertType(ExprType), false, "tmp");
return RValue::get(Val);
}
RValue CodeGenFunction::EmitLoadOfPropertyRefLValue(LValue LV,
QualType ExprType) {
return EmitObjCPropertyGet(LV.getPropertyRefExpr());
}
RValue CodeGenFunction::EmitLoadOfKVCRefLValue(LValue LV,
QualType ExprType) {
return EmitObjCPropertyGet(LV.getKVCRefExpr());
}
// If this is a reference to a subset of the elements of a vector, create an
// appropriate shufflevector.
RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV,
QualType ExprType) {
llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddr(),
LV.isVolatileQualified(), "tmp");
const llvm::Constant *Elts = LV.getExtVectorElts();
// If the result of the expression is a non-vector type, we must be
// extracting a single element. Just codegen as an extractelement.
const VectorType *ExprVT = ExprType->getAsVectorType();
if (!ExprVT) {
unsigned InIdx = getAccessedFieldNo(0, Elts);
llvm::Value *Elt = llvm::ConstantInt::get(llvm::Type::Int32Ty, InIdx);
return RValue::get(Builder.CreateExtractElement(Vec, Elt, "tmp"));
}
// Always use shuffle vector to try to retain the original program structure
unsigned NumResultElts = ExprVT->getNumElements();
llvm::SmallVector<llvm::Constant*, 4> Mask;
for (unsigned i = 0; i != NumResultElts; ++i) {
unsigned InIdx = getAccessedFieldNo(i, Elts);
Mask.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, InIdx));
}
llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
Vec = Builder.CreateShuffleVector(Vec,
llvm::UndefValue::get(Vec->getType()),
MaskV, "tmp");
return RValue::get(Vec);
}
/// EmitStoreThroughLValue - Store the specified rvalue into the specified
/// lvalue, where both are guaranteed to the have the same type, and that type
/// is 'Ty'.
void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
QualType Ty) {
if (!Dst.isSimple()) {
if (Dst.isVectorElt()) {
// Read/modify/write the vector, inserting the new element.
llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddr(),
Dst.isVolatileQualified(), "tmp");
Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
Dst.getVectorIdx(), "vecins");
Builder.CreateStore(Vec, Dst.getVectorAddr(),Dst.isVolatileQualified());
return;
}
// If this is an update of extended vector elements, insert them as
// appropriate.
if (Dst.isExtVectorElt())
return EmitStoreThroughExtVectorComponentLValue(Src, Dst, Ty);
if (Dst.isBitfield())
return EmitStoreThroughBitfieldLValue(Src, Dst, Ty);
if (Dst.isPropertyRef())
return EmitStoreThroughPropertyRefLValue(Src, Dst, Ty);
if (Dst.isKVCRef())
return EmitStoreThroughKVCRefLValue(Src, Dst, Ty);
assert(0 && "Unknown LValue type");
}
if (Dst.isObjCWeak()) {
// load of a __weak object.
llvm::Value *LvalueDst = Dst.getAddress();
llvm::Value *src = Src.getScalarVal();
CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
return;
}
if (Dst.isObjCStrong()) {
// load of a __strong object.
llvm::Value *LvalueDst = Dst.getAddress();
llvm::Value *src = Src.getScalarVal();
if (Dst.isObjCIvar())
CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, LvalueDst);
else
CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst);
return;
}
assert(Src.isScalar() && "Can't emit an agg store with this method");
EmitStoreOfScalar(Src.getScalarVal(), Dst.getAddress(),
Dst.isVolatileQualified());
}
void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
QualType Ty,
llvm::Value **Result) {
unsigned StartBit = Dst.getBitfieldStartBit();
unsigned BitfieldSize = Dst.getBitfieldSize();
llvm::Value *Ptr = Dst.getBitfieldAddr();
const llvm::Type *EltTy =
cast<llvm::PointerType>(Ptr->getType())->getElementType();
unsigned EltTySize = CGM.getTargetData().getTypeSizeInBits(EltTy);
// Get the new value, cast to the appropriate type and masked to
// exactly the size of the bit-field.
llvm::Value *SrcVal = Src.getScalarVal();
llvm::Value *NewVal = Builder.CreateIntCast(SrcVal, EltTy, false, "tmp");
llvm::Constant *Mask =
llvm::ConstantInt::get(llvm::APInt::getLowBitsSet(EltTySize, BitfieldSize));
NewVal = Builder.CreateAnd(NewVal, Mask, "bf.value");
// Return the new value of the bit-field, if requested.
if (Result) {
// Cast back to the proper type for result.
const llvm::Type *SrcTy = SrcVal->getType();
llvm::Value *SrcTrunc = Builder.CreateIntCast(NewVal, SrcTy, false,
"bf.reload.val");
// Sign extend if necessary.
if (Dst.isBitfieldSigned()) {
unsigned SrcTySize = CGM.getTargetData().getTypeSizeInBits(SrcTy);
llvm::Value *ExtraBits = llvm::ConstantInt::get(SrcTy,
SrcTySize - BitfieldSize);
SrcTrunc = Builder.CreateAShr(Builder.CreateShl(SrcTrunc, ExtraBits),
ExtraBits, "bf.reload.sext");
}
*Result = SrcTrunc;
}
// In some cases the bitfield may straddle two memory locations.
// Emit the low part first and check to see if the high needs to be
// done.
unsigned LowBits = std::min(BitfieldSize, EltTySize - StartBit);
llvm::Value *LowVal = Builder.CreateLoad(Ptr, Dst.isVolatileQualified(),
"bf.prev.low");
// Compute the mask for zero-ing the low part of this bitfield.
llvm::Constant *InvMask =
llvm::ConstantInt::get(~llvm::APInt::getBitsSet(EltTySize, StartBit,
StartBit + LowBits));
// Compute the new low part as
// LowVal = (LowVal & InvMask) | (NewVal << StartBit),
// with the shift of NewVal implicitly stripping the high bits.
llvm::Value *NewLowVal =
Builder.CreateShl(NewVal, llvm::ConstantInt::get(EltTy, StartBit),
"bf.value.lo");
LowVal = Builder.CreateAnd(LowVal, InvMask, "bf.prev.lo.cleared");
LowVal = Builder.CreateOr(LowVal, NewLowVal, "bf.new.lo");
// Write back.
Builder.CreateStore(LowVal, Ptr, Dst.isVolatileQualified());
// If the low part doesn't cover the bitfield emit a high part.
if (LowBits < BitfieldSize) {
unsigned HighBits = BitfieldSize - LowBits;
llvm::Value *HighPtr =
Builder.CreateGEP(Ptr, llvm::ConstantInt::get(llvm::Type::Int32Ty, 1),
"bf.ptr.hi");
llvm::Value *HighVal = Builder.CreateLoad(HighPtr,
Dst.isVolatileQualified(),
"bf.prev.hi");
// Compute the mask for zero-ing the high part of this bitfield.
llvm::Constant *InvMask =
llvm::ConstantInt::get(~llvm::APInt::getLowBitsSet(EltTySize, HighBits));
// Compute the new high part as
// HighVal = (HighVal & InvMask) | (NewVal lshr LowBits),
// where the high bits of NewVal have already been cleared and the
// shift stripping the low bits.
llvm::Value *NewHighVal =
Builder.CreateLShr(NewVal, llvm::ConstantInt::get(EltTy, LowBits),
"bf.value.high");
HighVal = Builder.CreateAnd(HighVal, InvMask, "bf.prev.hi.cleared");
HighVal = Builder.CreateOr(HighVal, NewHighVal, "bf.new.hi");
// Write back.
Builder.CreateStore(HighVal, HighPtr, Dst.isVolatileQualified());
}
}
void CodeGenFunction::EmitStoreThroughPropertyRefLValue(RValue Src,
LValue Dst,
QualType Ty) {
EmitObjCPropertySet(Dst.getPropertyRefExpr(), Src);
}
void CodeGenFunction::EmitStoreThroughKVCRefLValue(RValue Src,
LValue Dst,
QualType Ty) {
EmitObjCPropertySet(Dst.getKVCRefExpr(), Src);
}
void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
LValue Dst,
QualType Ty) {
// This access turns into a read/modify/write of the vector. Load the input
// value now.
llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddr(),
Dst.isVolatileQualified(), "tmp");
const llvm::Constant *Elts = Dst.getExtVectorElts();
llvm::Value *SrcVal = Src.getScalarVal();
if (const VectorType *VTy = Ty->getAsVectorType()) {
unsigned NumSrcElts = VTy->getNumElements();
unsigned NumDstElts =
cast<llvm::VectorType>(Vec->getType())->getNumElements();
if (NumDstElts == NumSrcElts) {
// Use shuffle vector is the src and destination are the same number
// of elements
llvm::SmallVector<llvm::Constant*, 4> Mask;
for (unsigned i = 0; i != NumSrcElts; ++i) {
unsigned InIdx = getAccessedFieldNo(i, Elts);
Mask.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, InIdx));
}
llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
Vec = Builder.CreateShuffleVector(SrcVal,
llvm::UndefValue::get(Vec->getType()),
MaskV, "tmp");
}
else if (NumDstElts > NumSrcElts) {
// Extended the source vector to the same length and then shuffle it
// into the destination.
// FIXME: since we're shuffling with undef, can we just use the indices
// into that? This could be simpler.
llvm::SmallVector<llvm::Constant*, 4> ExtMask;
unsigned i;
for (i = 0; i != NumSrcElts; ++i)
ExtMask.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, i));
for (; i != NumDstElts; ++i)
ExtMask.push_back(llvm::UndefValue::get(llvm::Type::Int32Ty));
llvm::Value *ExtMaskV = llvm::ConstantVector::get(&ExtMask[0],
ExtMask.size());
llvm::Value *ExtSrcVal = Builder.CreateShuffleVector(SrcVal,
llvm::UndefValue::get(SrcVal->getType()),
ExtMaskV, "tmp");
// build identity
llvm::SmallVector<llvm::Constant*, 4> Mask;
for (unsigned i = 0; i != NumDstElts; ++i) {
Mask.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, i));
}
// modify when what gets shuffled in
for (unsigned i = 0; i != NumSrcElts; ++i) {
unsigned Idx = getAccessedFieldNo(i, Elts);
Mask[Idx] =llvm::ConstantInt::get(llvm::Type::Int32Ty, i+NumDstElts);
}
llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size());
Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV, "tmp");
}
else {
// We should never shorten the vector
assert(0 && "unexpected shorten vector length");
}
} else {
// If the Src is a scalar (not a vector) it must be updating one element.
unsigned InIdx = getAccessedFieldNo(0, Elts);
llvm::Value *Elt = llvm::ConstantInt::get(llvm::Type::Int32Ty, InIdx);
Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt, "tmp");
}
Builder.CreateStore(Vec, Dst.getExtVectorAddr(), Dst.isVolatileQualified());
}
/// SetVarDeclObjCAttribute - Set __weak/__strong attributes into the LValue
/// object.
static void SetVarDeclObjCAttribute(ASTContext &Ctx, const Decl *VD,
const QualType &Ty, LValue &LV)
{
if (const ObjCGCAttr *A = VD->getAttr<ObjCGCAttr>()) {
ObjCGCAttr::GCAttrTypes attrType = A->getType();
LValue::SetObjCType(attrType == ObjCGCAttr::Weak,
attrType == ObjCGCAttr::Strong, LV);
}
else if (Ctx.getLangOptions().ObjC1 &&
Ctx.getLangOptions().getGCMode() != LangOptions::NonGC) {
// Default behavious under objective-c's gc is for objective-c pointers
// be treated as though they were declared as __strong.
if (Ctx.isObjCObjectPointerType(Ty))
LValue::SetObjCType(false, true, LV);
}
}
LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
const VarDecl *VD = dyn_cast<VarDecl>(E->getDecl());
if (VD && (VD->isBlockVarDecl() || isa<ParmVarDecl>(VD) ||
isa<ImplicitParamDecl>(VD))) {
LValue LV;
if (VD->getStorageClass() == VarDecl::Extern) {
LV = LValue::MakeAddr(CGM.GetAddrOfGlobalVar(VD),
E->getType().getCVRQualifiers());
}
else {
llvm::Value *V = LocalDeclMap[VD];
assert(V && "BlockVarDecl not entered in LocalDeclMap?");
LV = LValue::MakeAddr(V, E->getType().getCVRQualifiers());
}
if (VD->isBlockVarDecl() &&
(VD->getStorageClass() == VarDecl::Static ||
VD->getStorageClass() == VarDecl::Extern))
SetVarDeclObjCAttribute(getContext(), VD, E->getType(), LV);
return LV;
} else if (VD && VD->isFileVarDecl()) {
LValue LV = LValue::MakeAddr(CGM.GetAddrOfGlobalVar(VD),
E->getType().getCVRQualifiers());
SetVarDeclObjCAttribute(getContext(), VD, E->getType(), LV);
return LV;
} else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(E->getDecl())) {
return LValue::MakeAddr(CGM.GetAddrOfFunction(FD),
E->getType().getCVRQualifiers());
}
else if (const ImplicitParamDecl *IPD =
dyn_cast<ImplicitParamDecl>(E->getDecl())) {
llvm::Value *V = LocalDeclMap[IPD];
assert(V && "BlockVarDecl not entered in LocalDeclMap?");
return LValue::MakeAddr(V, E->getType().getCVRQualifiers());
}
assert(0 && "Unimp declref");
//an invalid LValue, but the assert will
//ensure that this point is never reached.
return LValue();
}
LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
// __extension__ doesn't affect lvalue-ness.
if (E->getOpcode() == UnaryOperator::Extension)
return EmitLValue(E->getSubExpr());
QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
switch (E->getOpcode()) {
default: assert(0 && "Unknown unary operator lvalue!");
case UnaryOperator::Deref:
return LValue::MakeAddr(EmitScalarExpr(E->getSubExpr()),
ExprTy->getAsPointerType()->getPointeeType()
.getCVRQualifiers());
case UnaryOperator::Real:
case UnaryOperator::Imag:
LValue LV = EmitLValue(E->getSubExpr());
unsigned Idx = E->getOpcode() == UnaryOperator::Imag;
return LValue::MakeAddr(Builder.CreateStructGEP(LV.getAddress(),
Idx, "idx"),
ExprTy.getCVRQualifiers());
}
}
LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
return LValue::MakeAddr(CGM.GetAddrOfConstantStringFromLiteral(E), 0);
}
LValue CodeGenFunction::EmitPredefinedFunctionName(unsigned Type) {
std::string GlobalVarName;
switch (Type) {
default:
assert(0 && "Invalid type");
case PredefinedExpr::Func:
GlobalVarName = "__func__.";
break;
case PredefinedExpr::Function:
GlobalVarName = "__FUNCTION__.";
break;
case PredefinedExpr::PrettyFunction:
// FIXME:: Demangle C++ method names
GlobalVarName = "__PRETTY_FUNCTION__.";
break;
}
std::string FunctionName;
if(const FunctionDecl *FD = dyn_cast<FunctionDecl>(CurFuncDecl)) {
FunctionName = FD->getNameAsString();
} else {
// Just get the mangled name.
FunctionName = CurFn->getName();
}
GlobalVarName += FunctionName;
llvm::Constant *C =
CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str());
return LValue::MakeAddr(C, 0);
}
LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
switch (E->getIdentType()) {
default:
return EmitUnsupportedLValue(E, "predefined expression");
case PredefinedExpr::Func:
case PredefinedExpr::Function:
case PredefinedExpr::PrettyFunction:
return EmitPredefinedFunctionName(E->getIdentType());
}
}
LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) {
// The index must always be an integer, which is not an aggregate. Emit it.
llvm::Value *Idx = EmitScalarExpr(E->getIdx());
// If the base is a vector type, then we are forming a vector element lvalue
// with this subscript.
if (E->getBase()->getType()->isVectorType()) {
// Emit the vector as an lvalue to get its address.
LValue LHS = EmitLValue(E->getBase());
assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
// FIXME: This should properly sign/zero/extend or truncate Idx to i32.
return LValue::MakeVectorElt(LHS.getAddress(), Idx,
E->getBase()->getType().getCVRQualifiers());
}
// The base must be a pointer, which is not an aggregate. Emit it.
llvm::Value *Base = EmitScalarExpr(E->getBase());
// Extend or truncate the index type to 32 or 64-bits.
QualType IdxTy = E->getIdx()->getType();
bool IdxSigned = IdxTy->isSignedIntegerType();
unsigned IdxBitwidth = cast<llvm::IntegerType>(Idx->getType())->getBitWidth();
if (IdxBitwidth != LLVMPointerWidth)
Idx = Builder.CreateIntCast(Idx, llvm::IntegerType::get(LLVMPointerWidth),
IdxSigned, "idxprom");
// We know that the pointer points to a type of the correct size, unless the
// size is a VLA.
if (const VariableArrayType *VAT =
getContext().getAsVariableArrayType(E->getType())) {
llvm::Value *VLASize = VLASizeMap[VAT];
Idx = Builder.CreateMul(Idx, VLASize);
QualType BaseType = getContext().getBaseElementType(VAT);
uint64_t BaseTypeSize = getContext().getTypeSize(BaseType) / 8;
Idx = Builder.CreateUDiv(Idx,
llvm::ConstantInt::get(Idx->getType(),
BaseTypeSize));
}
QualType ExprTy = getContext().getCanonicalType(E->getBase()->getType());
return LValue::MakeAddr(Builder.CreateGEP(Base, Idx, "arrayidx"),
ExprTy->getAsPointerType()->getPointeeType()
.getCVRQualifiers());
}
static
llvm::Constant *GenerateConstantVector(llvm::SmallVector<unsigned, 4> &Elts) {
llvm::SmallVector<llvm::Constant *, 4> CElts;
for (unsigned i = 0, e = Elts.size(); i != e; ++i)
CElts.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, Elts[i]));
return llvm::ConstantVector::get(&CElts[0], CElts.size());
}
LValue CodeGenFunction::
EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
// Emit the base vector as an l-value.
LValue Base = EmitLValue(E->getBase());
// Encode the element access list into a vector of unsigned indices.
llvm::SmallVector<unsigned, 4> Indices;
E->getEncodedElementAccess(Indices);
if (Base.isSimple()) {
llvm::Constant *CV = GenerateConstantVector(Indices);
return LValue::MakeExtVectorElt(Base.getAddress(), CV,
E->getBase()->getType().getCVRQualifiers());
}
assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
llvm::Constant *BaseElts = Base.getExtVectorElts();
llvm::SmallVector<llvm::Constant *, 4> CElts;
for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
if (isa<llvm::ConstantAggregateZero>(BaseElts))
CElts.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, 0));
else
CElts.push_back(BaseElts->getOperand(Indices[i]));
}
llvm::Constant *CV = llvm::ConstantVector::get(&CElts[0], CElts.size());
return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV,
E->getBase()->getType().getCVRQualifiers());
}
LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
bool isUnion = false;
bool isIvar = false;
Expr *BaseExpr = E->getBase();
llvm::Value *BaseValue = NULL;
unsigned CVRQualifiers=0;
// If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
if (E->isArrow()) {
BaseValue = EmitScalarExpr(BaseExpr);
const PointerType *PTy =
cast<PointerType>(getContext().getCanonicalType(BaseExpr->getType()));
if (PTy->getPointeeType()->isUnionType())
isUnion = true;
CVRQualifiers = PTy->getPointeeType().getCVRQualifiers();
}
else if (BaseExpr->getStmtClass() == Expr::ObjCPropertyRefExprClass ||
BaseExpr->getStmtClass() == Expr::ObjCKVCRefExprClass) {
RValue RV = EmitObjCPropertyGet(BaseExpr);
BaseValue = RV.getAggregateAddr();
if (BaseExpr->getType()->isUnionType())
isUnion = true;
CVRQualifiers = BaseExpr->getType().getCVRQualifiers();
}
else {
LValue BaseLV = EmitLValue(BaseExpr);
if (BaseLV.isObjCIvar())
isIvar = true;
// FIXME: this isn't right for bitfields.
BaseValue = BaseLV.getAddress();
if (BaseExpr->getType()->isUnionType())
isUnion = true;
CVRQualifiers = BaseExpr->getType().getCVRQualifiers();
}
FieldDecl *Field = dyn_cast<FieldDecl>(E->getMemberDecl());
// FIXME: Handle non-field member expressions
assert(Field && "No code generation for non-field member references");
LValue MemExpLV = EmitLValueForField(BaseValue, Field, isUnion, CVRQualifiers);
LValue::SetObjCIvar(MemExpLV, isIvar);
return MemExpLV;
}
LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value* BaseValue,
FieldDecl* Field,
unsigned CVRQualifiers) {
unsigned idx = CGM.getTypes().getLLVMFieldNo(Field);
// FIXME: CodeGenTypes should expose a method to get the appropriate
// type for FieldTy (the appropriate type is ABI-dependent).
const llvm::Type *FieldTy = CGM.getTypes().ConvertTypeForMem(Field->getType());
const llvm::PointerType *BaseTy =
cast<llvm::PointerType>(BaseValue->getType());
unsigned AS = BaseTy->getAddressSpace();
BaseValue = Builder.CreateBitCast(BaseValue,
llvm::PointerType::get(FieldTy, AS),
"tmp");
llvm::Value *V = Builder.CreateGEP(BaseValue,
llvm::ConstantInt::get(llvm::Type::Int32Ty, idx),
"tmp");
CodeGenTypes::BitFieldInfo bitFieldInfo =
CGM.getTypes().getBitFieldInfo(Field);
return LValue::MakeBitfield(V, bitFieldInfo.Begin, bitFieldInfo.Size,
Field->getType()->isSignedIntegerType(),
Field->getType().getCVRQualifiers()|CVRQualifiers);
}
LValue CodeGenFunction::EmitLValueForField(llvm::Value* BaseValue,
FieldDecl* Field,
bool isUnion,
unsigned CVRQualifiers)
{
if (Field->isBitField())
return EmitLValueForBitfield(BaseValue, Field, CVRQualifiers);
unsigned idx = CGM.getTypes().getLLVMFieldNo(Field);
llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
// Match union field type.
if (isUnion) {
const llvm::Type *FieldTy =
CGM.getTypes().ConvertTypeForMem(Field->getType());
const llvm::PointerType * BaseTy =
cast<llvm::PointerType>(BaseValue->getType());
unsigned AS = BaseTy->getAddressSpace();
V = Builder.CreateBitCast(V,
llvm::PointerType::get(FieldTy, AS),
"tmp");
}
LValue LV =
LValue::MakeAddr(V,
Field->getType().getCVRQualifiers()|CVRQualifiers);
if (const ObjCGCAttr *A = Field->getAttr<ObjCGCAttr>()) {
ObjCGCAttr::GCAttrTypes attrType = A->getType();
// __weak attribute on a field is ignored.
LValue::SetObjCType(false, attrType == ObjCGCAttr::Strong, LV);
}
else if (CGM.getLangOptions().ObjC1 &&
CGM.getLangOptions().getGCMode() != LangOptions::NonGC) {
QualType ExprTy = Field->getType();
if (getContext().isObjCObjectPointerType(ExprTy))
LValue::SetObjCType(false, true, LV);
}
return LV;
}
LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr* E)
{
const llvm::Type *LTy = ConvertType(E->getType());
llvm::Value *DeclPtr = CreateTempAlloca(LTy, ".compoundliteral");
const Expr* InitExpr = E->getInitializer();
LValue Result = LValue::MakeAddr(DeclPtr, E->getType().getCVRQualifiers());
if (E->getType()->isComplexType()) {
EmitComplexExprIntoAddr(InitExpr, DeclPtr, false);
} else if (hasAggregateLLVMType(E->getType())) {
EmitAnyExpr(InitExpr, DeclPtr, false);
} else {
EmitStoreThroughLValue(EmitAnyExpr(InitExpr), Result, E->getType());
}
return Result;
}
//===--------------------------------------------------------------------===//
// Expression Emission
//===--------------------------------------------------------------------===//
RValue CodeGenFunction::EmitCallExpr(const CallExpr *E) {
if (const ImplicitCastExpr *IcExpr =
dyn_cast<const ImplicitCastExpr>(E->getCallee()))
if (const DeclRefExpr *DRExpr =
dyn_cast<const DeclRefExpr>(IcExpr->getSubExpr()))
if (const FunctionDecl *FDecl =
dyn_cast<const FunctionDecl>(DRExpr->getDecl()))
if (unsigned builtinID = FDecl->getIdentifier()->getBuiltinID())
return EmitBuiltinExpr(builtinID, E);
if (E->getCallee()->getType()->isBlockPointerType())
return EmitBlockCallExpr(E);
llvm::Value *Callee = EmitScalarExpr(E->getCallee());
return EmitCallExpr(Callee, E->getCallee()->getType(),
E->arg_begin(), E->arg_end());
}
RValue CodeGenFunction::EmitCallExpr(Expr *FnExpr,
CallExpr::const_arg_iterator ArgBeg,
CallExpr::const_arg_iterator ArgEnd) {
llvm::Value *Callee = EmitScalarExpr(FnExpr);
return EmitCallExpr(Callee, FnExpr->getType(), ArgBeg, ArgEnd);
}
LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
// Can only get l-value for binary operator expressions which are a
// simple assignment of aggregate type.
if (E->getOpcode() != BinaryOperator::Assign)
return EmitUnsupportedLValue(E, "binary l-value expression");
llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
EmitAggExpr(E, Temp, false);
// FIXME: Are these qualifiers correct?
return LValue::MakeAddr(Temp, E->getType().getCVRQualifiers());
}
LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
// Can only get l-value for call expression returning aggregate type
RValue RV = EmitCallExpr(E);
return LValue::MakeAddr(RV.getAggregateAddr(),
E->getType().getCVRQualifiers());
}
LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
// FIXME: This shouldn't require another copy.
llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
EmitAggExpr(E, Temp, false);
return LValue::MakeAddr(Temp, E->getType().getCVRQualifiers());
}
LValue
CodeGenFunction::EmitCXXConditionDeclLValue(const CXXConditionDeclExpr *E) {
EmitLocalBlockVarDecl(*E->getVarDecl());
return EmitDeclRefLValue(E);
}
LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
// Can only get l-value for message expression returning aggregate type
RValue RV = EmitObjCMessageExpr(E);
// FIXME: can this be volatile?
return LValue::MakeAddr(RV.getAggregateAddr(),
E->getType().getCVRQualifiers());
}
llvm::Value *CodeGenFunction::EmitIvarOffset(ObjCInterfaceDecl *Interface,
const ObjCIvarDecl *Ivar) {
// Objective-C objects are traditionally C structures with their layout
// defined at compile-time. In some implementations, their layout is not
// defined until run time in order to allow instance variables to be added to
// a class without recompiling all of the subclasses. If this is the case
// then the CGObjCRuntime subclass must return true to LateBoundIvars and
// implement the lookup itself.
if (CGM.getObjCRuntime().LateBoundIVars())
assert(0 && "late-bound ivars are unsupported");
return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
}
LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
llvm::Value *BaseValue,
const ObjCIvarDecl *Ivar,
const FieldDecl *Field,
unsigned CVRQualifiers) {
// See comment in EmitIvarOffset.
if (CGM.getObjCRuntime().LateBoundIVars())
assert(0 && "late-bound ivars are unsupported");
LValue LV = CGM.getObjCRuntime().EmitObjCValueForIvar(*this,
ObjectTy,
BaseValue, Ivar, Field,
CVRQualifiers);
SetVarDeclObjCAttribute(getContext(), Ivar, Ivar->getType(), LV);
return LV;
}
LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
// FIXME: A lot of the code below could be shared with EmitMemberExpr.
llvm::Value *BaseValue = 0;
const Expr *BaseExpr = E->getBase();
unsigned CVRQualifiers = 0;
QualType ObjectTy;
if (E->isArrow()) {
BaseValue = EmitScalarExpr(BaseExpr);
const PointerType *PTy =
cast<PointerType>(getContext().getCanonicalType(BaseExpr->getType()));
ObjectTy = PTy->getPointeeType();
CVRQualifiers = ObjectTy.getCVRQualifiers();
} else {
LValue BaseLV = EmitLValue(BaseExpr);
// FIXME: this isn't right for bitfields.
BaseValue = BaseLV.getAddress();
ObjectTy = BaseExpr->getType();
CVRQualifiers = ObjectTy.getCVRQualifiers();
}
return EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
getContext().getFieldDecl(E), CVRQualifiers);
}
LValue
CodeGenFunction::EmitObjCPropertyRefLValue(const ObjCPropertyRefExpr *E) {
// This is a special l-value that just issues sends when we load or
// store through it.
return LValue::MakePropertyRef(E, E->getType().getCVRQualifiers());
}
LValue
CodeGenFunction::EmitObjCKVCRefLValue(const ObjCKVCRefExpr *E) {
// This is a special l-value that just issues sends when we load or
// store through it.
return LValue::MakeKVCRef(E, E->getType().getCVRQualifiers());
}
LValue
CodeGenFunction::EmitObjCSuperExpr(const ObjCSuperExpr *E) {
return EmitUnsupportedLValue(E, "use of super");
}
RValue CodeGenFunction::EmitCallExpr(llvm::Value *Callee, QualType CalleeType,
CallExpr::const_arg_iterator ArgBeg,
CallExpr::const_arg_iterator ArgEnd) {
// Get the actual function type. The callee type will always be a
// pointer to function type or a block pointer type.
QualType ResultType;
if (const BlockPointerType *BPT = dyn_cast<BlockPointerType>(CalleeType)) {
ResultType = BPT->getPointeeType()->getAsFunctionType()->getResultType();
} else {
assert(CalleeType->isFunctionPointerType() &&
"Call must have function pointer type!");
QualType FnType = CalleeType->getAsPointerType()->getPointeeType();
ResultType = FnType->getAsFunctionType()->getResultType();
}
CallArgList Args;
for (CallExpr::const_arg_iterator I = ArgBeg; I != ArgEnd; ++I)
Args.push_back(std::make_pair(EmitAnyExprToTemp(*I),
I->getType()));
return EmitCall(CGM.getTypes().getFunctionInfo(ResultType, Args),
Callee, Args);
}
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