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llvm-project/clang/lib/CodeGen/CGExprScalar.cpp
Chris Lattner 51924e517b Implement support for -fwrapv, rdar://7221421 
As part of this, pull together trapv handling into the same enum.

This also add support for NSW multiplies.

This also makes PCH disagreement on overflow behavior silent, since it
really doesn't matter except for warnings and codegen (no macros get 
defined etc).

llvm-svn: 106956
2010-06-26 21:25:03 +00:00

2126 lines
81 KiB
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//===--- CGExprScalar.cpp - Emit LLVM Code for Scalar Exprs ---------------===//
//
// 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 with scalar LLVM types as LLVM code.
//
//===----------------------------------------------------------------------===//
#include "CodeGenFunction.h"
#include "CGObjCRuntime.h"
#include "CodeGenModule.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/RecordLayout.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/Constants.h"
#include "llvm/Function.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Intrinsics.h"
#include "llvm/Module.h"
#include "llvm/Support/CFG.h"
#include "llvm/Target/TargetData.h"
#include <cstdarg>
using namespace clang;
using namespace CodeGen;
using llvm::Value;
//===----------------------------------------------------------------------===//
// Scalar Expression Emitter
//===----------------------------------------------------------------------===//
struct BinOpInfo {
Value *LHS;
Value *RHS;
QualType Ty; // Computation Type.
const BinaryOperator *E;
};
namespace {
class ScalarExprEmitter
: public StmtVisitor<ScalarExprEmitter, Value*> {
CodeGenFunction &CGF;
CGBuilderTy &Builder;
bool IgnoreResultAssign;
llvm::LLVMContext &VMContext;
public:
ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false)
: CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira),
VMContext(cgf.getLLVMContext()) {
}
//===--------------------------------------------------------------------===//
// Utilities
//===--------------------------------------------------------------------===//
bool TestAndClearIgnoreResultAssign() {
bool I = IgnoreResultAssign;
IgnoreResultAssign = false;
return I;
}
const llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); }
LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); }
LValue EmitCheckedLValue(const Expr *E) { return CGF.EmitCheckedLValue(E); }
Value *EmitLoadOfLValue(LValue LV, QualType T) {
return CGF.EmitLoadOfLValue(LV, T).getScalarVal();
}
/// EmitLoadOfLValue - Given an expression with complex type that represents a
/// value l-value, this method emits the address of the l-value, then loads
/// and returns the result.
Value *EmitLoadOfLValue(const Expr *E) {
return EmitLoadOfLValue(EmitCheckedLValue(E), E->getType());
}
/// EmitConversionToBool - Convert the specified expression value to a
/// boolean (i1) truth value. This is equivalent to "Val != 0".
Value *EmitConversionToBool(Value *Src, QualType DstTy);
/// EmitScalarConversion - Emit a conversion from the specified type to the
/// specified destination type, both of which are LLVM scalar types.
Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy);
/// EmitComplexToScalarConversion - Emit a conversion from the specified
/// complex type to the specified destination type, where the destination type
/// is an LLVM scalar type.
Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src,
QualType SrcTy, QualType DstTy);
/// EmitNullValue - Emit a value that corresponds to null for the given type.
Value *EmitNullValue(QualType Ty);
//===--------------------------------------------------------------------===//
// Visitor Methods
//===--------------------------------------------------------------------===//
Value *VisitStmt(Stmt *S) {
S->dump(CGF.getContext().getSourceManager());
assert(0 && "Stmt can't have complex result type!");
return 0;
}
Value *VisitExpr(Expr *S);
Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); }
// Leaves.
Value *VisitIntegerLiteral(const IntegerLiteral *E) {
return llvm::ConstantInt::get(VMContext, E->getValue());
}
Value *VisitFloatingLiteral(const FloatingLiteral *E) {
return llvm::ConstantFP::get(VMContext, E->getValue());
}
Value *VisitCharacterLiteral(const CharacterLiteral *E) {
return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
}
Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) {
return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
}
Value *VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) {
return EmitNullValue(E->getType());
}
Value *VisitGNUNullExpr(const GNUNullExpr *E) {
return EmitNullValue(E->getType());
}
Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) {
return llvm::ConstantInt::get(ConvertType(E->getType()),
CGF.getContext().typesAreCompatible(
E->getArgType1(), E->getArgType2()));
}
Value *VisitOffsetOfExpr(const OffsetOfExpr *E);
Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E);
Value *VisitAddrLabelExpr(const AddrLabelExpr *E) {
llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel());
return Builder.CreateBitCast(V, ConvertType(E->getType()));
}
// l-values.
Value *VisitDeclRefExpr(DeclRefExpr *E) {
Expr::EvalResult Result;
if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) {
assert(!Result.HasSideEffects && "Constant declref with side-effect?!");
return llvm::ConstantInt::get(VMContext, Result.Val.getInt());
}
return EmitLoadOfLValue(E);
}
Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) {
return CGF.EmitObjCSelectorExpr(E);
}
Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) {
return CGF.EmitObjCProtocolExpr(E);
}
Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
return EmitLoadOfLValue(E);
}
Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
return EmitLoadOfLValue(E);
}
Value *VisitObjCImplicitSetterGetterRefExpr(
ObjCImplicitSetterGetterRefExpr *E) {
return EmitLoadOfLValue(E);
}
Value *VisitObjCMessageExpr(ObjCMessageExpr *E) {
return CGF.EmitObjCMessageExpr(E).getScalarVal();
}
Value *VisitObjCIsaExpr(ObjCIsaExpr *E) {
LValue LV = CGF.EmitObjCIsaExpr(E);
Value *V = CGF.EmitLoadOfLValue(LV, E->getType()).getScalarVal();
return V;
}
Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E);
Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E);
Value *VisitMemberExpr(MemberExpr *E);
Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); }
Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
return EmitLoadOfLValue(E);
}
Value *VisitInitListExpr(InitListExpr *E);
Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) {
return CGF.CGM.EmitNullConstant(E->getType());
}
Value *VisitCastExpr(CastExpr *E) {
// Make sure to evaluate VLA bounds now so that we have them for later.
if (E->getType()->isVariablyModifiedType())
CGF.EmitVLASize(E->getType());
return EmitCastExpr(E);
}
Value *EmitCastExpr(CastExpr *E);
Value *VisitCallExpr(const CallExpr *E) {
if (E->getCallReturnType()->isReferenceType())
return EmitLoadOfLValue(E);
return CGF.EmitCallExpr(E).getScalarVal();
}
Value *VisitStmtExpr(const StmtExpr *E);
Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E);
// Unary Operators.
Value *VisitPrePostIncDec(const UnaryOperator *E, bool isInc, bool isPre) {
LValue LV = EmitLValue(E->getSubExpr());
return CGF.EmitScalarPrePostIncDec(E, LV, isInc, isPre);
}
Value *VisitUnaryPostDec(const UnaryOperator *E) {
return VisitPrePostIncDec(E, false, false);
}
Value *VisitUnaryPostInc(const UnaryOperator *E) {
return VisitPrePostIncDec(E, true, false);
}
Value *VisitUnaryPreDec(const UnaryOperator *E) {
return VisitPrePostIncDec(E, false, true);
}
Value *VisitUnaryPreInc(const UnaryOperator *E) {
return VisitPrePostIncDec(E, true, true);
}
Value *VisitUnaryAddrOf(const UnaryOperator *E) {
return EmitLValue(E->getSubExpr()).getAddress();
}
Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
Value *VisitUnaryPlus(const UnaryOperator *E) {
// This differs from gcc, though, most likely due to a bug in gcc.
TestAndClearIgnoreResultAssign();
return Visit(E->getSubExpr());
}
Value *VisitUnaryMinus (const UnaryOperator *E);
Value *VisitUnaryNot (const UnaryOperator *E);
Value *VisitUnaryLNot (const UnaryOperator *E);
Value *VisitUnaryReal (const UnaryOperator *E);
Value *VisitUnaryImag (const UnaryOperator *E);
Value *VisitUnaryExtension(const UnaryOperator *E) {
return Visit(E->getSubExpr());
}
Value *VisitUnaryOffsetOf(const UnaryOperator *E);
// C++
Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
return Visit(DAE->getExpr());
}
Value *VisitCXXThisExpr(CXXThisExpr *TE) {
return CGF.LoadCXXThis();
}
Value *VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) {
return CGF.EmitCXXExprWithTemporaries(E).getScalarVal();
}
Value *VisitCXXNewExpr(const CXXNewExpr *E) {
return CGF.EmitCXXNewExpr(E);
}
Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) {
CGF.EmitCXXDeleteExpr(E);
return 0;
}
Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) {
return llvm::ConstantInt::get(Builder.getInt1Ty(),
E->EvaluateTrait(CGF.getContext()));
}
Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) {
// C++ [expr.pseudo]p1:
// The result shall only be used as the operand for the function call
// operator (), and the result of such a call has type void. The only
// effect is the evaluation of the postfix-expression before the dot or
// arrow.
CGF.EmitScalarExpr(E->getBase());
return 0;
}
Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) {
return EmitNullValue(E->getType());
}
Value *VisitCXXThrowExpr(const CXXThrowExpr *E) {
CGF.EmitCXXThrowExpr(E);
return 0;
}
// Binary Operators.
Value *EmitMul(const BinOpInfo &Ops) {
if (Ops.Ty->isSignedIntegerType()) {
switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) {
case LangOptions::SOB_Undefined:
return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul");
case LangOptions::SOB_Defined:
return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul");
case LangOptions::SOB_Trapping:
return EmitOverflowCheckedBinOp(Ops);
}
}
if (Ops.LHS->getType()->isFPOrFPVectorTy())
return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul");
return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul");
}
/// Create a binary op that checks for overflow.
/// Currently only supports +, - and *.
Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops);
Value *EmitDiv(const BinOpInfo &Ops);
Value *EmitRem(const BinOpInfo &Ops);
Value *EmitAdd(const BinOpInfo &Ops);
Value *EmitSub(const BinOpInfo &Ops);
Value *EmitShl(const BinOpInfo &Ops);
Value *EmitShr(const BinOpInfo &Ops);
Value *EmitAnd(const BinOpInfo &Ops) {
return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and");
}
Value *EmitXor(const BinOpInfo &Ops) {
return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor");
}
Value *EmitOr (const BinOpInfo &Ops) {
return Builder.CreateOr(Ops.LHS, Ops.RHS, "or");
}
BinOpInfo EmitBinOps(const BinaryOperator *E);
LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
Value *(ScalarExprEmitter::*F)(const BinOpInfo &),
Value *&BitFieldResult);
Value *EmitCompoundAssign(const CompoundAssignOperator *E,
Value *(ScalarExprEmitter::*F)(const BinOpInfo &));
// Binary operators and binary compound assignment operators.
#define HANDLEBINOP(OP) \
Value *VisitBin ## OP(const BinaryOperator *E) { \
return Emit ## OP(EmitBinOps(E)); \
} \
Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \
return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \
}
HANDLEBINOP(Mul)
HANDLEBINOP(Div)
HANDLEBINOP(Rem)
HANDLEBINOP(Add)
HANDLEBINOP(Sub)
HANDLEBINOP(Shl)
HANDLEBINOP(Shr)
HANDLEBINOP(And)
HANDLEBINOP(Xor)
HANDLEBINOP(Or)
#undef HANDLEBINOP
// Comparisons.
Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc,
unsigned SICmpOpc, unsigned FCmpOpc);
#define VISITCOMP(CODE, UI, SI, FP) \
Value *VisitBin##CODE(const BinaryOperator *E) { \
return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \
llvm::FCmpInst::FP); }
VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT)
VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT)
VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE)
VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE)
VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ)
VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE)
#undef VISITCOMP
Value *VisitBinAssign (const BinaryOperator *E);
Value *VisitBinLAnd (const BinaryOperator *E);
Value *VisitBinLOr (const BinaryOperator *E);
Value *VisitBinComma (const BinaryOperator *E);
Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); }
Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); }
// Other Operators.
Value *VisitBlockExpr(const BlockExpr *BE);
Value *VisitConditionalOperator(const ConditionalOperator *CO);
Value *VisitChooseExpr(ChooseExpr *CE);
Value *VisitVAArgExpr(VAArgExpr *VE);
Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) {
return CGF.EmitObjCStringLiteral(E);
}
};
} // end anonymous namespace.
//===----------------------------------------------------------------------===//
// Utilities
//===----------------------------------------------------------------------===//
/// EmitConversionToBool - Convert the specified expression value to a
/// boolean (i1) truth value. This is equivalent to "Val != 0".
Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) {
assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs");
if (SrcType->isRealFloatingType()) {
// Compare against 0.0 for fp scalars.
llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType());
return Builder.CreateFCmpUNE(Src, Zero, "tobool");
}
if (SrcType->isMemberPointerType()) {
// Compare against -1.
llvm::Value *NegativeOne = llvm::Constant::getAllOnesValue(Src->getType());
return Builder.CreateICmpNE(Src, NegativeOne, "tobool");
}
assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) &&
"Unknown scalar type to convert");
// Because of the type rules of C, we often end up computing a logical value,
// then zero extending it to int, then wanting it as a logical value again.
// Optimize this common case.
if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) {
if (ZI->getOperand(0)->getType() ==
llvm::Type::getInt1Ty(CGF.getLLVMContext())) {
Value *Result = ZI->getOperand(0);
// If there aren't any more uses, zap the instruction to save space.
// Note that there can be more uses, for example if this
// is the result of an assignment.
if (ZI->use_empty())
ZI->eraseFromParent();
return Result;
}
}
// Compare against an integer or pointer null.
llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType());
return Builder.CreateICmpNE(Src, Zero, "tobool");
}
/// EmitScalarConversion - Emit a conversion from the specified type to the
/// specified destination type, both of which are LLVM scalar types.
Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType,
QualType DstType) {
SrcType = CGF.getContext().getCanonicalType(SrcType);
DstType = CGF.getContext().getCanonicalType(DstType);
if (SrcType == DstType) return Src;
if (DstType->isVoidType()) return 0;
llvm::LLVMContext &VMContext = CGF.getLLVMContext();
// Handle conversions to bool first, they are special: comparisons against 0.
if (DstType->isBooleanType())
return EmitConversionToBool(Src, SrcType);
const llvm::Type *DstTy = ConvertType(DstType);
// Ignore conversions like int -> uint.
if (Src->getType() == DstTy)
return Src;
// Handle pointer conversions next: pointers can only be converted to/from
// other pointers and integers. Check for pointer types in terms of LLVM, as
// some native types (like Obj-C id) may map to a pointer type.
if (isa<llvm::PointerType>(DstTy)) {
// The source value may be an integer, or a pointer.
if (isa<llvm::PointerType>(Src->getType()))
return Builder.CreateBitCast(Src, DstTy, "conv");
assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?");
// First, convert to the correct width so that we control the kind of
// extension.
const llvm::Type *MiddleTy =
llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth);
bool InputSigned = SrcType->isSignedIntegerType();
llvm::Value* IntResult =
Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv");
// Then, cast to pointer.
return Builder.CreateIntToPtr(IntResult, DstTy, "conv");
}
if (isa<llvm::PointerType>(Src->getType())) {
// Must be an ptr to int cast.
assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?");
return Builder.CreatePtrToInt(Src, DstTy, "conv");
}
// A scalar can be splatted to an extended vector of the same element type
if (DstType->isExtVectorType() && !SrcType->isVectorType()) {
// Cast the scalar to element type
QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType();
llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy);
// Insert the element in element zero of an undef vector
llvm::Value *UnV = llvm::UndefValue::get(DstTy);
llvm::Value *Idx =
llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0);
UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp");
// Splat the element across to all elements
llvm::SmallVector<llvm::Constant*, 16> Args;
unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements();
for (unsigned i = 0; i < NumElements; i++)
Args.push_back(llvm::ConstantInt::get(
llvm::Type::getInt32Ty(VMContext), 0));
llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements);
llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat");
return Yay;
}
// Allow bitcast from vector to integer/fp of the same size.
if (isa<llvm::VectorType>(Src->getType()) ||
isa<llvm::VectorType>(DstTy))
return Builder.CreateBitCast(Src, DstTy, "conv");
// Finally, we have the arithmetic types: real int/float.
if (isa<llvm::IntegerType>(Src->getType())) {
bool InputSigned = SrcType->isSignedIntegerType();
if (isa<llvm::IntegerType>(DstTy))
return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv");
else if (InputSigned)
return Builder.CreateSIToFP(Src, DstTy, "conv");
else
return Builder.CreateUIToFP(Src, DstTy, "conv");
}
assert(Src->getType()->isFloatingPointTy() && "Unknown real conversion");
if (isa<llvm::IntegerType>(DstTy)) {
if (DstType->isSignedIntegerType())
return Builder.CreateFPToSI(Src, DstTy, "conv");
else
return Builder.CreateFPToUI(Src, DstTy, "conv");
}
assert(DstTy->isFloatingPointTy() && "Unknown real conversion");
if (DstTy->getTypeID() < Src->getType()->getTypeID())
return Builder.CreateFPTrunc(Src, DstTy, "conv");
else
return Builder.CreateFPExt(Src, DstTy, "conv");
}
/// EmitComplexToScalarConversion - Emit a conversion from the specified complex
/// type to the specified destination type, where the destination type is an
/// LLVM scalar type.
Value *ScalarExprEmitter::
EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src,
QualType SrcTy, QualType DstTy) {
// Get the source element type.
SrcTy = SrcTy->getAs<ComplexType>()->getElementType();
// Handle conversions to bool first, they are special: comparisons against 0.
if (DstTy->isBooleanType()) {
// Complex != 0 -> (Real != 0) | (Imag != 0)
Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy);
Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy);
return Builder.CreateOr(Src.first, Src.second, "tobool");
}
// C99 6.3.1.7p2: "When a value of complex type is converted to a real type,
// the imaginary part of the complex value is discarded and the value of the
// real part is converted according to the conversion rules for the
// corresponding real type.
return EmitScalarConversion(Src.first, SrcTy, DstTy);
}
Value *ScalarExprEmitter::EmitNullValue(QualType Ty) {
const llvm::Type *LTy = ConvertType(Ty);
if (!Ty->isMemberPointerType())
return llvm::Constant::getNullValue(LTy);
assert(!Ty->isMemberFunctionPointerType() &&
"member function pointers are not scalar!");
// Itanium C++ ABI 2.3:
// A NULL pointer is represented as -1.
return llvm::ConstantInt::get(LTy, -1ULL, /*isSigned=*/true);
}
//===----------------------------------------------------------------------===//
// Visitor Methods
//===----------------------------------------------------------------------===//
Value *ScalarExprEmitter::VisitExpr(Expr *E) {
CGF.ErrorUnsupported(E, "scalar expression");
if (E->getType()->isVoidType())
return 0;
return llvm::UndefValue::get(CGF.ConvertType(E->getType()));
}
Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) {
// Vector Mask Case
if (E->getNumSubExprs() == 2 ||
(E->getNumSubExprs() == 3 && E->getExpr(2)->getType()->isVectorType())) {
Value* LHS = CGF.EmitScalarExpr(E->getExpr(0));
Value* RHS = CGF.EmitScalarExpr(E->getExpr(1));
Value* Mask;
const llvm::Type *I32Ty = llvm::Type::getInt32Ty(CGF.getLLVMContext());
const llvm::VectorType *LTy = cast<llvm::VectorType>(LHS->getType());
unsigned LHSElts = LTy->getNumElements();
if (E->getNumSubExprs() == 3) {
Mask = CGF.EmitScalarExpr(E->getExpr(2));
// Shuffle LHS & RHS into one input vector.
llvm::SmallVector<llvm::Constant*, 32> concat;
for (unsigned i = 0; i != LHSElts; ++i) {
concat.push_back(llvm::ConstantInt::get(I32Ty, 2*i));
concat.push_back(llvm::ConstantInt::get(I32Ty, 2*i+1));
}
Value* CV = llvm::ConstantVector::get(concat.begin(), concat.size());
LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat");
LHSElts *= 2;
} else {
Mask = RHS;
}
const llvm::VectorType *MTy = cast<llvm::VectorType>(Mask->getType());
llvm::Constant* EltMask;
// Treat vec3 like vec4.
if ((LHSElts == 6) && (E->getNumSubExprs() == 3))
EltMask = llvm::ConstantInt::get(MTy->getElementType(),
(1 << llvm::Log2_32(LHSElts+2))-1);
else if ((LHSElts == 3) && (E->getNumSubExprs() == 2))
EltMask = llvm::ConstantInt::get(MTy->getElementType(),
(1 << llvm::Log2_32(LHSElts+1))-1);
else
EltMask = llvm::ConstantInt::get(MTy->getElementType(),
(1 << llvm::Log2_32(LHSElts))-1);
// Mask off the high bits of each shuffle index.
llvm::SmallVector<llvm::Constant *, 32> MaskV;
for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i)
MaskV.push_back(EltMask);
Value* MaskBits = llvm::ConstantVector::get(MaskV.begin(), MaskV.size());
Mask = Builder.CreateAnd(Mask, MaskBits, "mask");
// newv = undef
// mask = mask & maskbits
// for each elt
// n = extract mask i
// x = extract val n
// newv = insert newv, x, i
const llvm::VectorType *RTy = llvm::VectorType::get(LTy->getElementType(),
MTy->getNumElements());
Value* NewV = llvm::UndefValue::get(RTy);
for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) {
Value *Indx = llvm::ConstantInt::get(I32Ty, i);
Indx = Builder.CreateExtractElement(Mask, Indx, "shuf_idx");
Indx = Builder.CreateZExt(Indx, I32Ty, "idx_zext");
// Handle vec3 special since the index will be off by one for the RHS.
if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) {
Value *cmpIndx, *newIndx;
cmpIndx = Builder.CreateICmpUGT(Indx, llvm::ConstantInt::get(I32Ty, 3),
"cmp_shuf_idx");
newIndx = Builder.CreateSub(Indx, llvm::ConstantInt::get(I32Ty, 1),
"shuf_idx_adj");
Indx = Builder.CreateSelect(cmpIndx, newIndx, Indx, "sel_shuf_idx");
}
Value *VExt = Builder.CreateExtractElement(LHS, Indx, "shuf_elt");
NewV = Builder.CreateInsertElement(NewV, VExt, Indx, "shuf_ins");
}
return NewV;
}
Value* V1 = CGF.EmitScalarExpr(E->getExpr(0));
Value* V2 = CGF.EmitScalarExpr(E->getExpr(1));
// Handle vec3 special since the index will be off by one for the RHS.
llvm::SmallVector<llvm::Constant*, 32> indices;
for (unsigned i = 2; i < E->getNumSubExprs(); i++) {
llvm::Constant *C = cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i)));
const llvm::VectorType *VTy = cast<llvm::VectorType>(V1->getType());
if (VTy->getNumElements() == 3) {
if (llvm::ConstantInt *CI = dyn_cast<llvm::ConstantInt>(C)) {
uint64_t cVal = CI->getZExtValue();
if (cVal > 3) {
C = llvm::ConstantInt::get(C->getType(), cVal-1);
}
}
}
indices.push_back(C);
}
Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size());
return Builder.CreateShuffleVector(V1, V2, SV, "shuffle");
}
Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) {
Expr::EvalResult Result;
if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) {
if (E->isArrow())
CGF.EmitScalarExpr(E->getBase());
else
EmitLValue(E->getBase());
return llvm::ConstantInt::get(VMContext, Result.Val.getInt());
}
return EmitLoadOfLValue(E);
}
Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
TestAndClearIgnoreResultAssign();
// Emit subscript expressions in rvalue context's. For most cases, this just
// loads the lvalue formed by the subscript expr. However, we have to be
// careful, because the base of a vector subscript is occasionally an rvalue,
// so we can't get it as an lvalue.
if (!E->getBase()->getType()->isVectorType())
return EmitLoadOfLValue(E);
// Handle the vector case. The base must be a vector, the index must be an
// integer value.
Value *Base = Visit(E->getBase());
Value *Idx = Visit(E->getIdx());
bool IdxSigned = E->getIdx()->getType()->isSignedIntegerType();
Idx = Builder.CreateIntCast(Idx,
llvm::Type::getInt32Ty(CGF.getLLVMContext()),
IdxSigned,
"vecidxcast");
return Builder.CreateExtractElement(Base, Idx, "vecext");
}
static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx,
unsigned Off, const llvm::Type *I32Ty) {
int MV = SVI->getMaskValue(Idx);
if (MV == -1)
return llvm::UndefValue::get(I32Ty);
return llvm::ConstantInt::get(I32Ty, Off+MV);
}
Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) {
bool Ignore = TestAndClearIgnoreResultAssign();
(void)Ignore;
assert (Ignore == false && "init list ignored");
unsigned NumInitElements = E->getNumInits();
if (E->hadArrayRangeDesignator())
CGF.ErrorUnsupported(E, "GNU array range designator extension");
const llvm::VectorType *VType =
dyn_cast<llvm::VectorType>(ConvertType(E->getType()));
// We have a scalar in braces. Just use the first element.
if (!VType)
return Visit(E->getInit(0));
unsigned ResElts = VType->getNumElements();
const llvm::Type *I32Ty = llvm::Type::getInt32Ty(CGF.getLLVMContext());
// Loop over initializers collecting the Value for each, and remembering
// whether the source was swizzle (ExtVectorElementExpr). This will allow
// us to fold the shuffle for the swizzle into the shuffle for the vector
// initializer, since LLVM optimizers generally do not want to touch
// shuffles.
unsigned CurIdx = 0;
bool VIsUndefShuffle = false;
llvm::Value *V = llvm::UndefValue::get(VType);
for (unsigned i = 0; i != NumInitElements; ++i) {
Expr *IE = E->getInit(i);
Value *Init = Visit(IE);
llvm::SmallVector<llvm::Constant*, 16> Args;
const llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType());
// Handle scalar elements. If the scalar initializer is actually one
// element of a different vector of the same width, use shuffle instead of
// extract+insert.
if (!VVT) {
if (isa<ExtVectorElementExpr>(IE)) {
llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init);
if (EI->getVectorOperandType()->getNumElements() == ResElts) {
llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand());
Value *LHS = 0, *RHS = 0;
if (CurIdx == 0) {
// insert into undef -> shuffle (src, undef)
Args.push_back(C);
for (unsigned j = 1; j != ResElts; ++j)
Args.push_back(llvm::UndefValue::get(I32Ty));
LHS = EI->getVectorOperand();
RHS = V;
VIsUndefShuffle = true;
} else if (VIsUndefShuffle) {
// insert into undefshuffle && size match -> shuffle (v, src)
llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V);
for (unsigned j = 0; j != CurIdx; ++j)
Args.push_back(getMaskElt(SVV, j, 0, I32Ty));
Args.push_back(llvm::ConstantInt::get(I32Ty,
ResElts + C->getZExtValue()));
for (unsigned j = CurIdx + 1; j != ResElts; ++j)
Args.push_back(llvm::UndefValue::get(I32Ty));
LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0);
RHS = EI->getVectorOperand();
VIsUndefShuffle = false;
}
if (!Args.empty()) {
llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts);
V = Builder.CreateShuffleVector(LHS, RHS, Mask);
++CurIdx;
continue;
}
}
}
Value *Idx = llvm::ConstantInt::get(I32Ty, CurIdx);
V = Builder.CreateInsertElement(V, Init, Idx, "vecinit");
VIsUndefShuffle = false;
++CurIdx;
continue;
}
unsigned InitElts = VVT->getNumElements();
// If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's
// input is the same width as the vector being constructed, generate an
// optimized shuffle of the swizzle input into the result.
unsigned Offset = (CurIdx == 0) ? 0 : ResElts;
if (isa<ExtVectorElementExpr>(IE)) {
llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init);
Value *SVOp = SVI->getOperand(0);
const llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType());
if (OpTy->getNumElements() == ResElts) {
for (unsigned j = 0; j != CurIdx; ++j) {
// If the current vector initializer is a shuffle with undef, merge
// this shuffle directly into it.
if (VIsUndefShuffle) {
Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0,
I32Ty));
} else {
Args.push_back(llvm::ConstantInt::get(I32Ty, j));
}
}
for (unsigned j = 0, je = InitElts; j != je; ++j)
Args.push_back(getMaskElt(SVI, j, Offset, I32Ty));
for (unsigned j = CurIdx + InitElts; j != ResElts; ++j)
Args.push_back(llvm::UndefValue::get(I32Ty));
if (VIsUndefShuffle)
V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0);
Init = SVOp;
}
}
// Extend init to result vector length, and then shuffle its contribution
// to the vector initializer into V.
if (Args.empty()) {
for (unsigned j = 0; j != InitElts; ++j)
Args.push_back(llvm::ConstantInt::get(I32Ty, j));
for (unsigned j = InitElts; j != ResElts; ++j)
Args.push_back(llvm::UndefValue::get(I32Ty));
llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts);
Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT),
Mask, "vext");
Args.clear();
for (unsigned j = 0; j != CurIdx; ++j)
Args.push_back(llvm::ConstantInt::get(I32Ty, j));
for (unsigned j = 0; j != InitElts; ++j)
Args.push_back(llvm::ConstantInt::get(I32Ty, j+Offset));
for (unsigned j = CurIdx + InitElts; j != ResElts; ++j)
Args.push_back(llvm::UndefValue::get(I32Ty));
}
// If V is undef, make sure it ends up on the RHS of the shuffle to aid
// merging subsequent shuffles into this one.
if (CurIdx == 0)
std::swap(V, Init);
llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts);
V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit");
VIsUndefShuffle = isa<llvm::UndefValue>(Init);
CurIdx += InitElts;
}
// FIXME: evaluate codegen vs. shuffling against constant null vector.
// Emit remaining default initializers.
const llvm::Type *EltTy = VType->getElementType();
// Emit remaining default initializers
for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) {
Value *Idx = llvm::ConstantInt::get(I32Ty, CurIdx);
llvm::Value *Init = llvm::Constant::getNullValue(EltTy);
V = Builder.CreateInsertElement(V, Init, Idx, "vecinit");
}
return V;
}
static bool ShouldNullCheckClassCastValue(const CastExpr *CE) {
const Expr *E = CE->getSubExpr();
if (CE->getCastKind() == CastExpr::CK_UncheckedDerivedToBase)
return false;
if (isa<CXXThisExpr>(E)) {
// We always assume that 'this' is never null.
return false;
}
if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) {
// And that lvalue casts are never null.
if (ICE->isLvalueCast())
return false;
}
return true;
}
// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts
// have to handle a more broad range of conversions than explicit casts, as they
// handle things like function to ptr-to-function decay etc.
Value *ScalarExprEmitter::EmitCastExpr(CastExpr *CE) {
Expr *E = CE->getSubExpr();
QualType DestTy = CE->getType();
CastExpr::CastKind Kind = CE->getCastKind();
if (!DestTy->isVoidType())
TestAndClearIgnoreResultAssign();
// Since almost all cast kinds apply to scalars, this switch doesn't have
// a default case, so the compiler will warn on a missing case. The cases
// are in the same order as in the CastKind enum.
switch (Kind) {
case CastExpr::CK_Unknown:
// FIXME: All casts should have a known kind!
//assert(0 && "Unknown cast kind!");
break;
case CastExpr::CK_AnyPointerToObjCPointerCast:
case CastExpr::CK_AnyPointerToBlockPointerCast:
case CastExpr::CK_BitCast: {
Value *Src = Visit(const_cast<Expr*>(E));
return Builder.CreateBitCast(Src, ConvertType(DestTy));
}
case CastExpr::CK_NoOp:
case CastExpr::CK_UserDefinedConversion:
return Visit(const_cast<Expr*>(E));
case CastExpr::CK_BaseToDerived: {
const CXXRecordDecl *DerivedClassDecl =
DestTy->getCXXRecordDeclForPointerType();
return CGF.GetAddressOfDerivedClass(Visit(E), DerivedClassDecl,
CE->getBasePath(),
ShouldNullCheckClassCastValue(CE));
}
case CastExpr::CK_UncheckedDerivedToBase:
case CastExpr::CK_DerivedToBase: {
const RecordType *DerivedClassTy =
E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>();
CXXRecordDecl *DerivedClassDecl =
cast<CXXRecordDecl>(DerivedClassTy->getDecl());
return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl,
CE->getBasePath(),
ShouldNullCheckClassCastValue(CE));
}
case CastExpr::CK_Dynamic: {
Value *V = Visit(const_cast<Expr*>(E));
const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE);
return CGF.EmitDynamicCast(V, DCE);
}
case CastExpr::CK_ToUnion:
assert(0 && "Should be unreachable!");
break;
case CastExpr::CK_ArrayToPointerDecay: {
assert(E->getType()->isArrayType() &&
"Array to pointer decay must have array source type!");
Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays.
// Note that VLA pointers are always decayed, so we don't need to do
// anything here.
if (!E->getType()->isVariableArrayType()) {
assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer");
assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType())
->getElementType()) &&
"Expected pointer to array");
V = Builder.CreateStructGEP(V, 0, "arraydecay");
}
return V;
}
case CastExpr::CK_FunctionToPointerDecay:
return EmitLValue(E).getAddress();
case CastExpr::CK_NullToMemberPointer:
return CGF.CGM.EmitNullConstant(DestTy);
case CastExpr::CK_BaseToDerivedMemberPointer:
case CastExpr::CK_DerivedToBaseMemberPointer: {
Value *Src = Visit(E);
// See if we need to adjust the pointer.
const CXXRecordDecl *BaseDecl =
cast<CXXRecordDecl>(E->getType()->getAs<MemberPointerType>()->
getClass()->getAs<RecordType>()->getDecl());
const CXXRecordDecl *DerivedDecl =
cast<CXXRecordDecl>(CE->getType()->getAs<MemberPointerType>()->
getClass()->getAs<RecordType>()->getDecl());
if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer)
std::swap(DerivedDecl, BaseDecl);
if (llvm::Constant *Adj =
CGF.CGM.GetNonVirtualBaseClassOffset(DerivedDecl, CE->getBasePath())){
if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer)
Src = Builder.CreateNSWSub(Src, Adj, "adj");
else
Src = Builder.CreateNSWAdd(Src, Adj, "adj");
}
return Src;
}
case CastExpr::CK_ConstructorConversion:
assert(0 && "Should be unreachable!");
break;
case CastExpr::CK_IntegralToPointer: {
Value *Src = Visit(const_cast<Expr*>(E));
// First, convert to the correct width so that we control the kind of
// extension.
const llvm::Type *MiddleTy =
llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth);
bool InputSigned = E->getType()->isSignedIntegerType();
llvm::Value* IntResult =
Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv");
return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy));
}
case CastExpr::CK_PointerToIntegral: {
Value *Src = Visit(const_cast<Expr*>(E));
return Builder.CreatePtrToInt(Src, ConvertType(DestTy));
}
case CastExpr::CK_ToVoid: {
CGF.EmitAnyExpr(E, 0, false, true);
return 0;
}
case CastExpr::CK_VectorSplat: {
const llvm::Type *DstTy = ConvertType(DestTy);
Value *Elt = Visit(const_cast<Expr*>(E));
// Insert the element in element zero of an undef vector
llvm::Value *UnV = llvm::UndefValue::get(DstTy);
llvm::Value *Idx =
llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0);
UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp");
// Splat the element across to all elements
llvm::SmallVector<llvm::Constant*, 16> Args;
unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements();
for (unsigned i = 0; i < NumElements; i++)
Args.push_back(llvm::ConstantInt::get(
llvm::Type::getInt32Ty(VMContext), 0));
llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements);
llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat");
return Yay;
}
case CastExpr::CK_IntegralCast:
case CastExpr::CK_IntegralToFloating:
case CastExpr::CK_FloatingToIntegral:
case CastExpr::CK_FloatingCast:
return EmitScalarConversion(Visit(E), E->getType(), DestTy);
case CastExpr::CK_MemberPointerToBoolean:
return CGF.EvaluateExprAsBool(E);
}
// Handle cases where the source is an non-complex type.
if (!CGF.hasAggregateLLVMType(E->getType())) {
Value *Src = Visit(const_cast<Expr*>(E));
// Use EmitScalarConversion to perform the conversion.
return EmitScalarConversion(Src, E->getType(), DestTy);
}
if (E->getType()->isAnyComplexType()) {
// Handle cases where the source is a complex type.
bool IgnoreImag = true;
bool IgnoreImagAssign = true;
bool IgnoreReal = IgnoreResultAssign;
bool IgnoreRealAssign = IgnoreResultAssign;
if (DestTy->isBooleanType())
IgnoreImagAssign = IgnoreImag = false;
else if (DestTy->isVoidType()) {
IgnoreReal = IgnoreImag = false;
IgnoreRealAssign = IgnoreImagAssign = true;
}
CodeGenFunction::ComplexPairTy V
= CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign,
IgnoreImagAssign);
return EmitComplexToScalarConversion(V, E->getType(), DestTy);
}
// Okay, this is a cast from an aggregate. It must be a cast to void. Just
// evaluate the result and return.
CGF.EmitAggExpr(E, 0, false, true);
return 0;
}
Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) {
return CGF.EmitCompoundStmt(*E->getSubStmt(),
!E->getType()->isVoidType()).getScalarVal();
}
Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) {
llvm::Value *V = CGF.GetAddrOfBlockDecl(E);
if (E->getType().isObjCGCWeak())
return CGF.CGM.getObjCRuntime().EmitObjCWeakRead(CGF, V);
return Builder.CreateLoad(V, "tmp");
}
//===----------------------------------------------------------------------===//
// Unary Operators
//===----------------------------------------------------------------------===//
Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
TestAndClearIgnoreResultAssign();
Value *Op = Visit(E->getSubExpr());
if (Op->getType()->isFPOrFPVectorTy())
return Builder.CreateFNeg(Op, "neg");
// Signed integer overflow is undefined behavior.
if (E->getType()->isSignedIntegerType()) {
switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) {
case LangOptions::SOB_Trapping:
// FIXME: Implement -ftrapv for negate.
case LangOptions::SOB_Undefined:
return Builder.CreateNSWNeg(Op, "neg");
case LangOptions::SOB_Defined:
return Builder.CreateNeg(Op, "neg");
}
}
return Builder.CreateNeg(Op, "neg");
}
Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
TestAndClearIgnoreResultAssign();
Value *Op = Visit(E->getSubExpr());
return Builder.CreateNot(Op, "neg");
}
Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) {
// Compare operand to zero.
Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr());
// Invert value.
// TODO: Could dynamically modify easy computations here. For example, if
// the operand is an icmp ne, turn into icmp eq.
BoolVal = Builder.CreateNot(BoolVal, "lnot");
// ZExt result to the expr type.
return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext");
}
Value *ScalarExprEmitter::VisitOffsetOfExpr(const OffsetOfExpr *E) {
Expr::EvalResult Result;
if(E->Evaluate(Result, CGF.getContext()))
return llvm::ConstantInt::get(VMContext, Result.Val.getInt());
// FIXME: Cannot support code generation for non-constant offsetof.
unsigned DiagID = CGF.CGM.getDiags().getCustomDiagID(Diagnostic::Error,
"cannot compile non-constant __builtin_offsetof");
CGF.CGM.getDiags().Report(CGF.getContext().getFullLoc(E->getLocStart()),
DiagID)
<< E->getSourceRange();
return llvm::Constant::getNullValue(ConvertType(E->getType()));
}
/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of
/// argument of the sizeof expression as an integer.
Value *
ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) {
QualType TypeToSize = E->getTypeOfArgument();
if (E->isSizeOf()) {
if (const VariableArrayType *VAT =
CGF.getContext().getAsVariableArrayType(TypeToSize)) {
if (E->isArgumentType()) {
// sizeof(type) - make sure to emit the VLA size.
CGF.EmitVLASize(TypeToSize);
} else {
// C99 6.5.3.4p2: If the argument is an expression of type
// VLA, it is evaluated.
CGF.EmitAnyExpr(E->getArgumentExpr());
}
return CGF.GetVLASize(VAT);
}
}
// If this isn't sizeof(vla), the result must be constant; use the constant
// folding logic so we don't have to duplicate it here.
Expr::EvalResult Result;
E->Evaluate(Result, CGF.getContext());
return llvm::ConstantInt::get(VMContext, Result.Val.getInt());
}
Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) {
Expr *Op = E->getSubExpr();
if (Op->getType()->isAnyComplexType())
return CGF.EmitComplexExpr(Op, false, true, false, true).first;
return Visit(Op);
}
Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) {
Expr *Op = E->getSubExpr();
if (Op->getType()->isAnyComplexType())
return CGF.EmitComplexExpr(Op, true, false, true, false).second;
// __imag on a scalar returns zero. Emit the subexpr to ensure side
// effects are evaluated, but not the actual value.
if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid)
CGF.EmitLValue(Op);
else
CGF.EmitScalarExpr(Op, true);
return llvm::Constant::getNullValue(ConvertType(E->getType()));
}
Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) {
Value* ResultAsPtr = EmitLValue(E->getSubExpr()).getAddress();
const llvm::Type* ResultType = ConvertType(E->getType());
return Builder.CreatePtrToInt(ResultAsPtr, ResultType, "offsetof");
}
//===----------------------------------------------------------------------===//
// Binary Operators
//===----------------------------------------------------------------------===//
BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) {
TestAndClearIgnoreResultAssign();
BinOpInfo Result;
Result.LHS = Visit(E->getLHS());
Result.RHS = Visit(E->getRHS());
Result.Ty = E->getType();
Result.E = E;
return Result;
}
LValue ScalarExprEmitter::EmitCompoundAssignLValue(
const CompoundAssignOperator *E,
Value *(ScalarExprEmitter::*Func)(const BinOpInfo &),
Value *&BitFieldResult) {
QualType LHSTy = E->getLHS()->getType();
BitFieldResult = 0;
BinOpInfo OpInfo;
if (E->getComputationResultType()->isAnyComplexType()) {
// This needs to go through the complex expression emitter, but it's a tad
// complicated to do that... I'm leaving it out for now. (Note that we do
// actually need the imaginary part of the RHS for multiplication and
// division.)
CGF.ErrorUnsupported(E, "complex compound assignment");
llvm::UndefValue::get(CGF.ConvertType(E->getType()));
return LValue();
}
// Emit the RHS first. __block variables need to have the rhs evaluated
// first, plus this should improve codegen a little.
OpInfo.RHS = Visit(E->getRHS());
OpInfo.Ty = E->getComputationResultType();
OpInfo.E = E;
// Load/convert the LHS.
LValue LHSLV = EmitCheckedLValue(E->getLHS());
OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy);
OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy,
E->getComputationLHSType());
// Expand the binary operator.
Value *Result = (this->*Func)(OpInfo);
// Convert the result back to the LHS type.
Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy);
// Store the result value into the LHS lvalue. Bit-fields are handled
// specially because the result is altered by the store, i.e., [C99 6.5.16p1]
// 'An assignment expression has the value of the left operand after the
// assignment...'.
if (LHSLV.isBitField()) {
if (!LHSLV.isVolatileQualified()) {
CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy,
&Result);
BitFieldResult = Result;
return LHSLV;
} else
CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy);
} else
CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy);
return LHSLV;
}
Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E,
Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) {
bool Ignore = TestAndClearIgnoreResultAssign();
Value *BitFieldResult;
LValue LHSLV = EmitCompoundAssignLValue(E, Func, BitFieldResult);
if (BitFieldResult)
return BitFieldResult;
if (Ignore)
return 0;
return EmitLoadOfLValue(LHSLV, E->getType());
}
Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) {
if (Ops.LHS->getType()->isFPOrFPVectorTy())
return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div");
else if (Ops.Ty->isUnsignedIntegerType())
return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div");
else
return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div");
}
Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) {
// Rem in C can't be a floating point type: C99 6.5.5p2.
if (Ops.Ty->isUnsignedIntegerType())
return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem");
else
return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem");
}
Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) {
unsigned IID;
unsigned OpID = 0;
switch (Ops.E->getOpcode()) {
case BinaryOperator::Add:
case BinaryOperator::AddAssign:
OpID = 1;
IID = llvm::Intrinsic::sadd_with_overflow;
break;
case BinaryOperator::Sub:
case BinaryOperator::SubAssign:
OpID = 2;
IID = llvm::Intrinsic::ssub_with_overflow;
break;
case BinaryOperator::Mul:
case BinaryOperator::MulAssign:
OpID = 3;
IID = llvm::Intrinsic::smul_with_overflow;
break;
default:
assert(false && "Unsupported operation for overflow detection");
IID = 0;
}
OpID <<= 1;
OpID |= 1;
const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty);
llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1);
Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS);
Value *result = Builder.CreateExtractValue(resultAndOverflow, 0);
Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1);
// Branch in case of overflow.
llvm::BasicBlock *initialBB = Builder.GetInsertBlock();
llvm::BasicBlock *overflowBB =
CGF.createBasicBlock("overflow", CGF.CurFn);
llvm::BasicBlock *continueBB =
CGF.createBasicBlock("overflow.continue", CGF.CurFn);
Builder.CreateCondBr(overflow, overflowBB, continueBB);
// Handle overflow
Builder.SetInsertPoint(overflowBB);
// Handler is:
// long long *__overflow_handler)(long long a, long long b, char op,
// char width)
std::vector<const llvm::Type*> handerArgTypes;
handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext));
handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext));
handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext));
handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext));
llvm::FunctionType *handlerTy = llvm::FunctionType::get(
llvm::Type::getInt64Ty(VMContext), handerArgTypes, false);
llvm::Value *handlerFunction =
CGF.CGM.getModule().getOrInsertGlobal("__overflow_handler",
llvm::PointerType::getUnqual(handlerTy));
handlerFunction = Builder.CreateLoad(handlerFunction);
llvm::Value *handlerResult = Builder.CreateCall4(handlerFunction,
Builder.CreateSExt(Ops.LHS, llvm::Type::getInt64Ty(VMContext)),
Builder.CreateSExt(Ops.RHS, llvm::Type::getInt64Ty(VMContext)),
llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), OpID),
llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext),
cast<llvm::IntegerType>(opTy)->getBitWidth()));
handlerResult = Builder.CreateTrunc(handlerResult, opTy);
Builder.CreateBr(continueBB);
// Set up the continuation
Builder.SetInsertPoint(continueBB);
// Get the correct result
llvm::PHINode *phi = Builder.CreatePHI(opTy);
phi->reserveOperandSpace(2);
phi->addIncoming(result, initialBB);
phi->addIncoming(handlerResult, overflowBB);
return phi;
}
Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) {
if (!Ops.Ty->isAnyPointerType()) {
if (Ops.Ty->isSignedIntegerType()) {
switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) {
case LangOptions::SOB_Undefined:
return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add");
case LangOptions::SOB_Defined:
return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add");
case LangOptions::SOB_Trapping:
return EmitOverflowCheckedBinOp(Ops);
}
}
if (Ops.LHS->getType()->isFPOrFPVectorTy())
return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add");
return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add");
}
if (Ops.Ty->isPointerType() &&
Ops.Ty->getAs<PointerType>()->isVariableArrayType()) {
// The amount of the addition needs to account for the VLA size
CGF.ErrorUnsupported(Ops.E, "VLA pointer addition");
}
Value *Ptr, *Idx;
Expr *IdxExp;
const PointerType *PT = Ops.E->getLHS()->getType()->getAs<PointerType>();
const ObjCObjectPointerType *OPT =
Ops.E->getLHS()->getType()->getAs<ObjCObjectPointerType>();
if (PT || OPT) {
Ptr = Ops.LHS;
Idx = Ops.RHS;
IdxExp = Ops.E->getRHS();
} else { // int + pointer
PT = Ops.E->getRHS()->getType()->getAs<PointerType>();
OPT = Ops.E->getRHS()->getType()->getAs<ObjCObjectPointerType>();
assert((PT || OPT) && "Invalid add expr");
Ptr = Ops.RHS;
Idx = Ops.LHS;
IdxExp = Ops.E->getLHS();
}
unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth();
if (Width < CGF.LLVMPointerWidth) {
// Zero or sign extend the pointer value based on whether the index is
// signed or not.
const llvm::Type *IdxType =
llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth);
if (IdxExp->getType()->isSignedIntegerType())
Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext");
else
Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext");
}
const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType();
// Handle interface types, which are not represented with a concrete type.
if (const ObjCObjectType *OIT = ElementType->getAs<ObjCObjectType>()) {
llvm::Value *InterfaceSize =
llvm::ConstantInt::get(Idx->getType(),
CGF.getContext().getTypeSizeInChars(OIT).getQuantity());
Idx = Builder.CreateMul(Idx, InterfaceSize);
const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext);
Value *Casted = Builder.CreateBitCast(Ptr, i8Ty);
Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr");
return Builder.CreateBitCast(Res, Ptr->getType());
}
// Explicitly handle GNU void* and function pointer arithmetic extensions. The
// GNU void* casts amount to no-ops since our void* type is i8*, but this is
// future proof.
if (ElementType->isVoidType() || ElementType->isFunctionType()) {
const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext);
Value *Casted = Builder.CreateBitCast(Ptr, i8Ty);
Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr");
return Builder.CreateBitCast(Res, Ptr->getType());
}
return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr");
}
Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) {
if (!isa<llvm::PointerType>(Ops.LHS->getType())) {
if (Ops.Ty->isSignedIntegerType()) {
switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) {
case LangOptions::SOB_Undefined:
return Builder.CreateNSWSub(Ops.LHS, Ops.RHS, "sub");
case LangOptions::SOB_Defined:
return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub");
case LangOptions::SOB_Trapping:
return EmitOverflowCheckedBinOp(Ops);
}
}
if (Ops.LHS->getType()->isFPOrFPVectorTy())
return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub");
return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub");
}
if (Ops.E->getLHS()->getType()->isPointerType() &&
Ops.E->getLHS()->getType()->getAs<PointerType>()->isVariableArrayType()) {
// The amount of the addition needs to account for the VLA size for
// ptr-int
// The amount of the division needs to account for the VLA size for
// ptr-ptr.
CGF.ErrorUnsupported(Ops.E, "VLA pointer subtraction");
}
const QualType LHSType = Ops.E->getLHS()->getType();
const QualType LHSElementType = LHSType->getPointeeType();
if (!isa<llvm::PointerType>(Ops.RHS->getType())) {
// pointer - int
Value *Idx = Ops.RHS;
unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth();
if (Width < CGF.LLVMPointerWidth) {
// Zero or sign extend the pointer value based on whether the index is
// signed or not.
const llvm::Type *IdxType =
llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth);
if (Ops.E->getRHS()->getType()->isSignedIntegerType())
Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext");
else
Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext");
}
Idx = Builder.CreateNeg(Idx, "sub.ptr.neg");
// Handle interface types, which are not represented with a concrete type.
if (const ObjCObjectType *OIT = LHSElementType->getAs<ObjCObjectType>()) {
llvm::Value *InterfaceSize =
llvm::ConstantInt::get(Idx->getType(),
CGF.getContext().
getTypeSizeInChars(OIT).getQuantity());
Idx = Builder.CreateMul(Idx, InterfaceSize);
const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext);
Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty);
Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr");
return Builder.CreateBitCast(Res, Ops.LHS->getType());
}
// Explicitly handle GNU void* and function pointer arithmetic
// extensions. The GNU void* casts amount to no-ops since our void* type is
// i8*, but this is future proof.
if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) {
const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext);
Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty);
Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr");
return Builder.CreateBitCast(Res, Ops.LHS->getType());
}
return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr");
} else {
// pointer - pointer
Value *LHS = Ops.LHS;
Value *RHS = Ops.RHS;
CharUnits ElementSize;
// Handle GCC extension for pointer arithmetic on void* and function pointer
// types.
if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) {
ElementSize = CharUnits::One();
} else {
ElementSize = CGF.getContext().getTypeSizeInChars(LHSElementType);
}
const llvm::Type *ResultType = ConvertType(Ops.Ty);
LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast");
RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub");
// Optimize out the shift for element size of 1.
if (ElementSize.isOne())
return BytesBetween;
// Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since
// pointer difference in C is only defined in the case where both operands
// are pointing to elements of an array.
Value *BytesPerElt =
llvm::ConstantInt::get(ResultType, ElementSize.getQuantity());
return Builder.CreateExactSDiv(BytesBetween, BytesPerElt, "sub.ptr.div");
}
}
Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) {
// LLVM requires the LHS and RHS to be the same type: promote or truncate the
// RHS to the same size as the LHS.
Value *RHS = Ops.RHS;
if (Ops.LHS->getType() != RHS->getType())
RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom");
if (CGF.CatchUndefined
&& isa<llvm::IntegerType>(Ops.LHS->getType())) {
unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth();
llvm::BasicBlock *Cont = CGF.createBasicBlock("cont");
CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS,
llvm::ConstantInt::get(RHS->getType(), Width)),
Cont, CGF.getTrapBB());
CGF.EmitBlock(Cont);
}
return Builder.CreateShl(Ops.LHS, RHS, "shl");
}
Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) {
// LLVM requires the LHS and RHS to be the same type: promote or truncate the
// RHS to the same size as the LHS.
Value *RHS = Ops.RHS;
if (Ops.LHS->getType() != RHS->getType())
RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom");
if (CGF.CatchUndefined
&& isa<llvm::IntegerType>(Ops.LHS->getType())) {
unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth();
llvm::BasicBlock *Cont = CGF.createBasicBlock("cont");
CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS,
llvm::ConstantInt::get(RHS->getType(), Width)),
Cont, CGF.getTrapBB());
CGF.EmitBlock(Cont);
}
if (Ops.Ty->isUnsignedIntegerType())
return Builder.CreateLShr(Ops.LHS, RHS, "shr");
return Builder.CreateAShr(Ops.LHS, RHS, "shr");
}
Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc,
unsigned SICmpOpc, unsigned FCmpOpc) {
TestAndClearIgnoreResultAssign();
Value *Result;
QualType LHSTy = E->getLHS()->getType();
if (LHSTy->isMemberFunctionPointerType()) {
Value *LHSPtr = CGF.EmitAnyExprToTemp(E->getLHS()).getAggregateAddr();
Value *RHSPtr = CGF.EmitAnyExprToTemp(E->getRHS()).getAggregateAddr();
llvm::Value *LHSFunc = Builder.CreateStructGEP(LHSPtr, 0);
LHSFunc = Builder.CreateLoad(LHSFunc);
llvm::Value *RHSFunc = Builder.CreateStructGEP(RHSPtr, 0);
RHSFunc = Builder.CreateLoad(RHSFunc);
Value *ResultF = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
LHSFunc, RHSFunc, "cmp.func");
Value *NullPtr = llvm::Constant::getNullValue(LHSFunc->getType());
Value *ResultNull = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
LHSFunc, NullPtr, "cmp.null");
llvm::Value *LHSAdj = Builder.CreateStructGEP(LHSPtr, 1);
LHSAdj = Builder.CreateLoad(LHSAdj);
llvm::Value *RHSAdj = Builder.CreateStructGEP(RHSPtr, 1);
RHSAdj = Builder.CreateLoad(RHSAdj);
Value *ResultA = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
LHSAdj, RHSAdj, "cmp.adj");
if (E->getOpcode() == BinaryOperator::EQ) {
Result = Builder.CreateOr(ResultNull, ResultA, "or.na");
Result = Builder.CreateAnd(Result, ResultF, "and.f");
} else {
assert(E->getOpcode() == BinaryOperator::NE &&
"Member pointer comparison other than == or != ?");
Result = Builder.CreateAnd(ResultNull, ResultA, "and.na");
Result = Builder.CreateOr(Result, ResultF, "or.f");
}
} else if (!LHSTy->isAnyComplexType()) {
Value *LHS = Visit(E->getLHS());
Value *RHS = Visit(E->getRHS());
if (LHS->getType()->isFPOrFPVectorTy()) {
Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc,
LHS, RHS, "cmp");
} else if (LHSTy->isSignedIntegerType()) {
Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc,
LHS, RHS, "cmp");
} else {
// Unsigned integers and pointers.
Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
LHS, RHS, "cmp");
}
// If this is a vector comparison, sign extend the result to the appropriate
// vector integer type and return it (don't convert to bool).
if (LHSTy->isVectorType())
return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext");
} else {
// Complex Comparison: can only be an equality comparison.
CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS());
CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS());
QualType CETy = LHSTy->getAs<ComplexType>()->getElementType();
Value *ResultR, *ResultI;
if (CETy->isRealFloatingType()) {
ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc,
LHS.first, RHS.first, "cmp.r");
ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc,
LHS.second, RHS.second, "cmp.i");
} else {
// Complex comparisons can only be equality comparisons. As such, signed
// and unsigned opcodes are the same.
ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
LHS.first, RHS.first, "cmp.r");
ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
LHS.second, RHS.second, "cmp.i");
}
if (E->getOpcode() == BinaryOperator::EQ) {
Result = Builder.CreateAnd(ResultR, ResultI, "and.ri");
} else {
assert(E->getOpcode() == BinaryOperator::NE &&
"Complex comparison other than == or != ?");
Result = Builder.CreateOr(ResultR, ResultI, "or.ri");
}
}
return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType());
}
Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) {
bool Ignore = TestAndClearIgnoreResultAssign();
// __block variables need to have the rhs evaluated first, plus this should
// improve codegen just a little.
Value *RHS = Visit(E->getRHS());
LValue LHS = EmitCheckedLValue(E->getLHS());
// Store the value into the LHS. Bit-fields are handled specially
// because the result is altered by the store, i.e., [C99 6.5.16p1]
// 'An assignment expression has the value of the left operand after
// the assignment...'.
if (LHS.isBitField()) {
if (!LHS.isVolatileQualified()) {
CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(),
&RHS);
return RHS;
} else
CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType());
} else
CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType());
if (Ignore)
return 0;
return EmitLoadOfLValue(LHS, E->getType());
}
Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) {
const llvm::Type *ResTy = ConvertType(E->getType());
// If we have 0 && RHS, see if we can elide RHS, if so, just return 0.
// If we have 1 && X, just emit X without inserting the control flow.
if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) {
if (Cond == 1) { // If we have 1 && X, just emit X.
Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
// ZExt result to int or bool.
return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext");
}
// 0 && RHS: If it is safe, just elide the RHS, and return 0/false.
if (!CGF.ContainsLabel(E->getRHS()))
return llvm::Constant::getNullValue(ResTy);
}
llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end");
llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs");
// Branch on the LHS first. If it is false, go to the failure (cont) block.
CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock);
// Any edges into the ContBlock are now from an (indeterminate number of)
// edges from this first condition. All of these values will be false. Start
// setting up the PHI node in the Cont Block for this.
llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext),
"", ContBlock);
PN->reserveOperandSpace(2); // Normal case, two inputs.
for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock);
PI != PE; ++PI)
PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI);
CGF.BeginConditionalBranch();
CGF.EmitBlock(RHSBlock);
Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
CGF.EndConditionalBranch();
// Reaquire the RHS block, as there may be subblocks inserted.
RHSBlock = Builder.GetInsertBlock();
// Emit an unconditional branch from this block to ContBlock. Insert an entry
// into the phi node for the edge with the value of RHSCond.
CGF.EmitBlock(ContBlock);
PN->addIncoming(RHSCond, RHSBlock);
// ZExt result to int.
return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext");
}
Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) {
const llvm::Type *ResTy = ConvertType(E->getType());
// If we have 1 || RHS, see if we can elide RHS, if so, just return 1.
// If we have 0 || X, just emit X without inserting the control flow.
if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) {
if (Cond == -1) { // If we have 0 || X, just emit X.
Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
// ZExt result to int or bool.
return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext");
}
// 1 || RHS: If it is safe, just elide the RHS, and return 1/true.
if (!CGF.ContainsLabel(E->getRHS()))
return llvm::ConstantInt::get(ResTy, 1);
}
llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end");
llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs");
// Branch on the LHS first. If it is true, go to the success (cont) block.
CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock);
// Any edges into the ContBlock are now from an (indeterminate number of)
// edges from this first condition. All of these values will be true. Start
// setting up the PHI node in the Cont Block for this.
llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext),
"", ContBlock);
PN->reserveOperandSpace(2); // Normal case, two inputs.
for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock);
PI != PE; ++PI)
PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI);
CGF.BeginConditionalBranch();
// Emit the RHS condition as a bool value.
CGF.EmitBlock(RHSBlock);
Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
CGF.EndConditionalBranch();
// Reaquire the RHS block, as there may be subblocks inserted.
RHSBlock = Builder.GetInsertBlock();
// Emit an unconditional branch from this block to ContBlock. Insert an entry
// into the phi node for the edge with the value of RHSCond.
CGF.EmitBlock(ContBlock);
PN->addIncoming(RHSCond, RHSBlock);
// ZExt result to int.
return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext");
}
Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) {
CGF.EmitStmt(E->getLHS());
CGF.EnsureInsertPoint();
return Visit(E->getRHS());
}
//===----------------------------------------------------------------------===//
// Other Operators
//===----------------------------------------------------------------------===//
/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified
/// expression is cheap enough and side-effect-free enough to evaluate
/// unconditionally instead of conditionally. This is used to convert control
/// flow into selects in some cases.
static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E,
CodeGenFunction &CGF) {
if (const ParenExpr *PE = dyn_cast<ParenExpr>(E))
return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr(), CGF);
// TODO: Allow anything we can constant fold to an integer or fp constant.
if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) ||
isa<FloatingLiteral>(E))
return true;
// Non-volatile automatic variables too, to get "cond ? X : Y" where
// X and Y are local variables.
if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl()))
if (VD->hasLocalStorage() && !(CGF.getContext()
.getCanonicalType(VD->getType())
.isVolatileQualified()))
return true;
return false;
}
Value *ScalarExprEmitter::
VisitConditionalOperator(const ConditionalOperator *E) {
TestAndClearIgnoreResultAssign();
// If the condition constant folds and can be elided, try to avoid emitting
// the condition and the dead arm.
if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){
Expr *Live = E->getLHS(), *Dead = E->getRHS();
if (Cond == -1)
std::swap(Live, Dead);
// If the dead side doesn't have labels we need, and if the Live side isn't
// the gnu missing ?: extension (which we could handle, but don't bother
// to), just emit the Live part.
if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part
Live) // Live part isn't missing.
return Visit(Live);
}
// If this is a really simple expression (like x ? 4 : 5), emit this as a
// select instead of as control flow. We can only do this if it is cheap and
// safe to evaluate the LHS and RHS unconditionally.
if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS(),
CGF) &&
isCheapEnoughToEvaluateUnconditionally(E->getRHS(), CGF)) {
llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond());
llvm::Value *LHS = Visit(E->getLHS());
llvm::Value *RHS = Visit(E->getRHS());
return Builder.CreateSelect(CondV, LHS, RHS, "cond");
}
llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
Value *CondVal = 0;
// If we don't have the GNU missing condition extension, emit a branch on bool
// the normal way.
if (E->getLHS()) {
// Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for
// the branch on bool.
CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
} else {
// Otherwise, for the ?: extension, evaluate the conditional and then
// convert it to bool the hard way. We do this explicitly because we need
// the unconverted value for the missing middle value of the ?:.
CondVal = CGF.EmitScalarExpr(E->getCond());
// In some cases, EmitScalarConversion will delete the "CondVal" expression
// if there are no extra uses (an optimization). Inhibit this by making an
// extra dead use, because we're going to add a use of CondVal later. We
// don't use the builder for this, because we don't want it to get optimized
// away. This leaves dead code, but the ?: extension isn't common.
new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder",
Builder.GetInsertBlock());
Value *CondBoolVal =
CGF.EmitScalarConversion(CondVal, E->getCond()->getType(),
CGF.getContext().BoolTy);
Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock);
}
CGF.BeginConditionalBranch();
CGF.EmitBlock(LHSBlock);
// Handle the GNU extension for missing LHS.
Value *LHS;
if (E->getLHS())
LHS = Visit(E->getLHS());
else // Perform promotions, to handle cases like "short ?: int"
LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType());
CGF.EndConditionalBranch();
LHSBlock = Builder.GetInsertBlock();
CGF.EmitBranch(ContBlock);
CGF.BeginConditionalBranch();
CGF.EmitBlock(RHSBlock);
Value *RHS = Visit(E->getRHS());
CGF.EndConditionalBranch();
RHSBlock = Builder.GetInsertBlock();
CGF.EmitBranch(ContBlock);
CGF.EmitBlock(ContBlock);
// If the LHS or RHS is a throw expression, it will be legitimately null.
if (!LHS)
return RHS;
if (!RHS)
return LHS;
// Create a PHI node for the real part.
llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond");
PN->reserveOperandSpace(2);
PN->addIncoming(LHS, LHSBlock);
PN->addIncoming(RHS, RHSBlock);
return PN;
}
Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) {
return Visit(E->getChosenSubExpr(CGF.getContext()));
}
Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) {
llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr());
llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType());
// If EmitVAArg fails, we fall back to the LLVM instruction.
if (!ArgPtr)
return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType()));
// FIXME Volatility.
return Builder.CreateLoad(ArgPtr);
}
Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) {
return CGF.BuildBlockLiteralTmp(BE);
}
//===----------------------------------------------------------------------===//
// Entry Point into this File
//===----------------------------------------------------------------------===//
/// EmitScalarExpr - Emit the computation of the specified expression of scalar
/// type, ignoring the result.
Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) {
assert(E && !hasAggregateLLVMType(E->getType()) &&
"Invalid scalar expression to emit");
return ScalarExprEmitter(*this, IgnoreResultAssign)
.Visit(const_cast<Expr*>(E));
}
/// EmitScalarConversion - Emit a conversion from the specified type to the
/// specified destination type, both of which are LLVM scalar types.
Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy,
QualType DstTy) {
assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) &&
"Invalid scalar expression to emit");
return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy);
}
/// EmitComplexToScalarConversion - Emit a conversion from the specified complex
/// type to the specified destination type, where the destination type is an
/// LLVM scalar type.
Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src,
QualType SrcTy,
QualType DstTy) {
assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) &&
"Invalid complex -> scalar conversion");
return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy,
DstTy);
}
LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) {
llvm::Value *V;
// object->isa or (*object).isa
// Generate code as for: *(Class*)object
// build Class* type
const llvm::Type *ClassPtrTy = ConvertType(E->getType());
Expr *BaseExpr = E->getBase();
if (BaseExpr->isLvalue(getContext()) != Expr::LV_Valid) {
V = CreateTempAlloca(ClassPtrTy, "resval");
llvm::Value *Src = EmitScalarExpr(BaseExpr);
Builder.CreateStore(Src, V);
LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType()));
V = ScalarExprEmitter(*this).EmitLoadOfLValue(LV, E->getType());
}
else {
if (E->isArrow())
V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr);
else
V = EmitLValue(BaseExpr).getAddress();
}
// build Class* type
ClassPtrTy = ClassPtrTy->getPointerTo();
V = Builder.CreateBitCast(V, ClassPtrTy);
LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType()));
return LV;
}
LValue CodeGenFunction::EmitCompoundAssignOperatorLValue(
const CompoundAssignOperator *E) {
ScalarExprEmitter Scalar(*this);
Value *BitFieldResult = 0;
switch (E->getOpcode()) {
#define COMPOUND_OP(Op) \
case BinaryOperator::Op##Assign: \
return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \
BitFieldResult)
COMPOUND_OP(Mul);
COMPOUND_OP(Div);
COMPOUND_OP(Rem);
COMPOUND_OP(Add);
COMPOUND_OP(Sub);
COMPOUND_OP(Shl);
COMPOUND_OP(Shr);
COMPOUND_OP(And);
COMPOUND_OP(Xor);
COMPOUND_OP(Or);
#undef COMPOUND_OP
case BinaryOperator::PtrMemD:
case BinaryOperator::PtrMemI:
case BinaryOperator::Mul:
case BinaryOperator::Div:
case BinaryOperator::Rem:
case BinaryOperator::Add:
case BinaryOperator::Sub:
case BinaryOperator::Shl:
case BinaryOperator::Shr:
case BinaryOperator::LT:
case BinaryOperator::GT:
case BinaryOperator::LE:
case BinaryOperator::GE:
case BinaryOperator::EQ:
case BinaryOperator::NE:
case BinaryOperator::And:
case BinaryOperator::Xor:
case BinaryOperator::Or:
case BinaryOperator::LAnd:
case BinaryOperator::LOr:
case BinaryOperator::Assign:
case BinaryOperator::Comma:
assert(false && "Not valid compound assignment operators");
break;
}
llvm_unreachable("Unhandled compound assignment operator");
}
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