mirrors/llvm-project
0
0
Fork 0
mirror of https://github.com/llvm/llvm-project.git synced 2025-05-01 21:06:04 +00:00
Code Issues Projects Releases Wiki Activity
llvm-project/clang/lib/CodeGen/CGExprScalar.cpp
Fariborz Jahanian 88cc2340de Renamed ObjCKVCRefExpr to ObjCImplctSetterGetterRefExpr. 
Removed an unnecessary loop to get to setters incoming
argument. Added DoxyGen comments. Still more work
to do in this area (WIP).

llvm-svn: 79365
2009-08-18 20:50:23 +00:00

1661 lines
64 KiB
C++
Raw Blame History

//===--- 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 "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/Compiler.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 VISIBILITY_HIDDEN 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); }
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(EmitLValue(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);
//===--------------------------------------------------------------------===//
// 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 llvm::Constant::getNullValue(ConvertType(E->getType()));
}
Value *VisitGNUNullExpr(const GNUNullExpr *E) {
return llvm::Constant::getNullValue(ConvertType(E->getType()));
}
Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) {
return llvm::ConstantInt::get(ConvertType(E->getType()),
CGF.getContext().typesAreCompatible(
E->getArgType1(), E->getArgType2()));
}
Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E);
Value *VisitAddrLabelExpr(const AddrLabelExpr *E) {
llvm::Value *V =
llvm::ConstantInt::get(llvm::Type::getInt32Ty(CGF.getLLVMContext()),
CGF.GetIDForAddrOfLabel(E->getLabel()));
return Builder.CreateIntToPtr(V, ConvertType(E->getType()));
}
// l-values.
Value *VisitDeclRefExpr(DeclRefExpr *E) {
if (const EnumConstantDecl *EC = dyn_cast<EnumConstantDecl>(E->getDecl()))
return llvm::ConstantInt::get(VMContext, EC->getInitVal());
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 *VisitObjCImplctSetterGetterRefExpr(
ObjCImplctSetterGetterRefExpr *E) {
return EmitLoadOfLValue(E);
}
Value *VisitObjCMessageExpr(ObjCMessageExpr *E) {
return CGF.EmitObjCMessageExpr(E).getScalarVal();
}
Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E);
Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E);
Value *VisitMemberExpr(Expr *E) { return EmitLoadOfLValue(E); }
Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); }
Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
return EmitLoadOfLValue(E);
}
Value *VisitStringLiteral(Expr *E) { return EmitLValue(E).getAddress(); }
Value *VisitObjCEncodeExpr(const ObjCEncodeExpr *E) {
return EmitLValue(E).getAddress();
}
Value *VisitPredefinedExpr(Expr *E) { return EmitLValue(E).getAddress(); }
Value *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 NumVectorElements = VType->getNumElements();
const llvm::Type *ElementType = VType->getElementType();
// Emit individual vector element stores.
llvm::Value *V = llvm::UndefValue::get(VType);
// Emit initializers
unsigned i;
for (i = 0; i < NumInitElements; ++i) {
Value *NewV = Visit(E->getInit(i));
Value *Idx =
llvm::ConstantInt::get(llvm::Type::getInt32Ty(CGF.getLLVMContext()), i);
V = Builder.CreateInsertElement(V, NewV, Idx);
}
// Emit remaining default initializers
for (/* Do not initialize i*/; i < NumVectorElements; ++i) {
Value *Idx =
llvm::ConstantInt::get(llvm::Type::getInt32Ty(CGF.getLLVMContext()), i);
llvm::Value *NewV = llvm::Constant::getNullValue(ElementType);
V = Builder.CreateInsertElement(V, NewV, Idx);
}
return V;
}
Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) {
return llvm::Constant::getNullValue(ConvertType(E->getType()));
}
Value *VisitImplicitCastExpr(const ImplicitCastExpr *E);
Value *VisitCastExpr(const 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->getSubExpr(), E->getType());
}
Value *EmitCastExpr(const Expr *E, QualType T);
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);
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;
}
// Binary Operators.
Value *EmitMul(const BinOpInfo &Ops) {
if (CGF.getContext().getLangOptions().OverflowChecking
&& Ops.Ty->isSignedIntegerType())
return EmitOverflowCheckedBinOp(Ops);
if (Ops.LHS->getType()->isFPOrFPVector())
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);
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);
// 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()) {
// FIXME: This is ABI specific.
// 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())) {
// Some heavy lifting for derived to base conversion.
if (const CXXRecordDecl *ClassDecl =
SrcType->getCXXRecordDeclForPointerType())
if (const CXXRecordDecl *BaseClassDecl =
DstType->getCXXRecordDeclForPointerType())
Src = CGF.AddressCXXOfBaseClass(Src, ClassDecl, BaseClassDecl);
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->getAsExtVectorType()->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()->isFloatingPoint() && "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->isFloatingPoint() && "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->getAsComplexType()->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);
}
//===----------------------------------------------------------------------===//
// 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) {
llvm::SmallVector<llvm::Constant*, 32> indices;
for (unsigned i = 2; i < E->getNumSubExprs(); i++) {
indices.push_back(cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i))));
}
Value* V1 = CGF.EmitScalarExpr(E->getExpr(0));
Value* V2 = CGF.EmitScalarExpr(E->getExpr(1));
Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size());
return Builder.CreateShuffleVector(V1, V2, SV, "shuffle");
}
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");
}
/// VisitImplicitCastExpr - Implicit casts are the same as normal casts, but
/// also handle things like function to pointer-to-function decay, and array to
/// pointer decay.
Value *ScalarExprEmitter::VisitImplicitCastExpr(const ImplicitCastExpr *E) {
const Expr *Op = E->getSubExpr();
// If this is due to array->pointer conversion, emit the array expression as
// an l-value.
if (Op->getType()->isArrayType()) {
assert(E->getCastKind() == CastExpr::CK_ArrayToPointerDecay);
Value *V = EmitLValue(Op).getAddress(); // Bitfields can't be arrays.
// Note that VLA pointers are always decayed, so we don't need to do
// anything here.
if (!Op->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");
}
// The resultant pointer type can be implicitly casted to other pointer
// types as well (e.g. void*) and can be implicitly converted to integer.
const llvm::Type *DestTy = ConvertType(E->getType());
if (V->getType() != DestTy) {
if (isa<llvm::PointerType>(DestTy))
V = Builder.CreateBitCast(V, DestTy, "ptrconv");
else {
assert(isa<llvm::IntegerType>(DestTy) && "Unknown array decay");
V = Builder.CreatePtrToInt(V, DestTy, "ptrconv");
}
}
return V;
}
return EmitCastExpr(Op, E->getType());
}
// 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(const Expr *E, QualType DestTy) {
if (!DestTy->isVoidType())
TestAndClearIgnoreResultAssign();
// 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) {
return Builder.CreateLoad(CGF.GetAddrOfBlockDecl(E), false, "tmp");
}
//===----------------------------------------------------------------------===//
// Unary Operators
//===----------------------------------------------------------------------===//
Value *ScalarExprEmitter::VisitPrePostIncDec(const UnaryOperator *E,
bool isInc, bool isPre) {
LValue LV = EmitLValue(E->getSubExpr());
QualType ValTy = E->getSubExpr()->getType();
Value *InVal = CGF.EmitLoadOfLValue(LV, ValTy).getScalarVal();
llvm::LLVMContext &VMContext = CGF.getLLVMContext();
int AmountVal = isInc ? 1 : -1;
if (ValTy->isPointerType() &&
ValTy->getAs<PointerType>()->isVariableArrayType()) {
// The amount of the addition/subtraction needs to account for the VLA size
CGF.ErrorUnsupported(E, "VLA pointer inc/dec");
}
Value *NextVal;
if (const llvm::PointerType *PT =
dyn_cast<llvm::PointerType>(InVal->getType())) {
llvm::Constant *Inc =
llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), AmountVal);
if (!isa<llvm::FunctionType>(PT->getElementType())) {
QualType PTEE = ValTy->getPointeeType();
if (const ObjCInterfaceType *OIT =
dyn_cast<ObjCInterfaceType>(PTEE)) {
// Handle interface types, which are not represented with a concrete type.
int size = CGF.getContext().getTypeSize(OIT) / 8;
if (!isInc)
size = -size;
Inc = llvm::ConstantInt::get(Inc->getType(), size);
const llvm::Type *i8Ty =
llvm::PointerType::getUnqual(llvm::Type::getInt8Ty(VMContext));
InVal = Builder.CreateBitCast(InVal, i8Ty);
NextVal = Builder.CreateGEP(InVal, Inc, "add.ptr");
llvm::Value *lhs = LV.getAddress();
lhs = Builder.CreateBitCast(lhs, llvm::PointerType::getUnqual(i8Ty));
LV = LValue::MakeAddr(lhs, ValTy.getCVRQualifiers(),
CGF.getContext().getObjCGCAttrKind(ValTy));
} else
NextVal = Builder.CreateInBoundsGEP(InVal, Inc, "ptrincdec");
} else {
const llvm::Type *i8Ty =
llvm::PointerType::getUnqual(llvm::Type::getInt8Ty(VMContext));
NextVal = Builder.CreateBitCast(InVal, i8Ty, "tmp");
NextVal = Builder.CreateGEP(NextVal, Inc, "ptrincdec");
NextVal = Builder.CreateBitCast(NextVal, InVal->getType());
}
} else if (InVal->getType() == llvm::Type::getInt1Ty(VMContext) && isInc) {
// Bool++ is an interesting case, due to promotion rules, we get:
// Bool++ -> Bool = Bool+1 -> Bool = (int)Bool+1 ->
// Bool = ((int)Bool+1) != 0
// An interesting aspect of this is that increment is always true.
// Decrement does not have this property.
NextVal = llvm::ConstantInt::getTrue(VMContext);
} else if (isa<llvm::IntegerType>(InVal->getType())) {
NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal);
// Signed integer overflow is undefined behavior.
if (ValTy->isSignedIntegerType())
NextVal = Builder.CreateNSWAdd(InVal, NextVal, isInc ? "inc" : "dec");
else
NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec");
} else {
// Add the inc/dec to the real part.
if (InVal->getType() == llvm::Type::getFloatTy(VMContext))
NextVal =
llvm::ConstantFP::get(VMContext,
llvm::APFloat(static_cast<float>(AmountVal)));
else if (InVal->getType() == llvm::Type::getDoubleTy(VMContext))
NextVal =
llvm::ConstantFP::get(VMContext,
llvm::APFloat(static_cast<double>(AmountVal)));
else {
llvm::APFloat F(static_cast<float>(AmountVal));
bool ignored;
F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero,
&ignored);
NextVal = llvm::ConstantFP::get(VMContext, F);
}
NextVal = Builder.CreateFAdd(InVal, NextVal, isInc ? "inc" : "dec");
}
// Store the updated result through the lvalue.
if (LV.isBitfield())
CGF.EmitStoreThroughBitfieldLValue(RValue::get(NextVal), LV, ValTy,
&NextVal);
else
CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV, ValTy);
// If this is a postinc, return the value read from memory, otherwise use the
// updated value.
return isPre ? NextVal : InVal;
}
Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
TestAndClearIgnoreResultAssign();
Value *Op = Visit(E->getSubExpr());
if (Op->getType()->isFPOrFPVector())
return Builder.CreateFNeg(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");
}
/// 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;
}
Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E,
Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) {
bool Ignore = TestAndClearIgnoreResultAssign();
QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType();
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");
return llvm::UndefValue::get(CGF.ConvertType(E->getType()));
}
// 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 = EmitLValue(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);
return Result;
} else
CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy);
} else
CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy);
if (Ignore)
return 0;
return EmitLoadOfLValue(LHSLV, E->getType());
}
Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) {
if (Ops.LHS->getType()->isFPOrFPVector())
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 (CGF.getContext().getLangOptions().OverflowChecking &&
Ops.Ty->isSignedIntegerType())
return EmitOverflowCheckedBinOp(Ops);
if (Ops.LHS->getType()->isFPOrFPVector())
return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add");
// Signed integer overflow is undefined behavior.
if (Ops.Ty->isSignedIntegerType())
return Builder.CreateNSWAdd(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()->getAsObjCObjectPointerType();
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()->getAsObjCObjectPointerType();
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 ObjCInterfaceType *OIT = dyn_cast<ObjCInterfaceType>(ElementType)) {
llvm::Value *InterfaceSize =
llvm::ConstantInt::get(Idx->getType(),
CGF.getContext().getTypeSize(OIT) / 8);
Idx = Builder.CreateMul(Idx, InterfaceSize);
const llvm::Type *i8Ty =
llvm::PointerType::getUnqual(llvm::Type::getInt8Ty(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::PointerType::getUnqual(llvm::Type::getInt8Ty(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 (CGF.getContext().getLangOptions().OverflowChecking
&& Ops.Ty->isSignedIntegerType())
return EmitOverflowCheckedBinOp(Ops);
if (Ops.LHS->getType()->isFPOrFPVector())
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 ObjCInterfaceType *OIT =
dyn_cast<ObjCInterfaceType>(LHSElementType)) {
llvm::Value *InterfaceSize =
llvm::ConstantInt::get(Idx->getType(),
CGF.getContext().getTypeSize(OIT) / 8);
Idx = Builder.CreateMul(Idx, InterfaceSize);
const llvm::Type *i8Ty =
llvm::PointerType::getUnqual(llvm::Type::getInt8Ty(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::PointerType::getUnqual(llvm::Type::getInt8Ty(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;
uint64_t ElementSize;
// Handle GCC extension for pointer arithmetic on void* and function pointer
// types.
if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) {
ElementSize = 1;
} else {
ElementSize = CGF.getContext().getTypeSize(LHSElementType) / 8;
}
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 == 1)
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);
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");
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 (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->isAnyComplexType()) {
Value *LHS = Visit(E->getLHS());
Value *RHS = Visit(E->getRHS());
if (LHS->getType()->isFPOrFPVector()) {
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->getAsComplexType()->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 = EmitLValue(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) {
// 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.
return Builder.CreateZExt(RHSCond, CGF.LLVMIntTy, "land.ext");
}
// 0 && RHS: If it is safe, just elide the RHS, and return 0.
if (!CGF.ContainsLabel(E->getRHS()))
return llvm::Constant::getNullValue(CGF.LLVMIntTy);
}
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.PushConditionalTempDestruction();
CGF.EmitBlock(RHSBlock);
Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
CGF.PopConditionalTempDestruction();
// 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.CreateZExt(PN, CGF.LLVMIntTy, "land.ext");
}
Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) {
// 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.
return Builder.CreateZExt(RHSCond, CGF.LLVMIntTy, "lor.ext");
}
// 1 || RHS: If it is safe, just elide the RHS, and return 1.
if (!CGF.ContainsLabel(E->getRHS()))
return llvm::ConstantInt::get(CGF.LLVMIntTy, 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.PushConditionalTempDestruction();
// Emit the RHS condition as a bool value.
CGF.EmitBlock(RHSBlock);
Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
CGF.PopConditionalTempDestruction();
// 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.CreateZExt(PN, CGF.LLVMIntTy, "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) {
if (const ParenExpr *PE = dyn_cast<ParenExpr>(E))
return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr());
// 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() && !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()) &&
isCheapEnoughToEvaluateUnconditionally(E->getRHS())) {
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.PushConditionalTempDestruction();
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.PopConditionalTempDestruction();
LHSBlock = Builder.GetInsertBlock();
CGF.EmitBranch(ContBlock);
CGF.PushConditionalTempDestruction();
CGF.EmitBlock(RHSBlock);
Value *RHS = Visit(E->getRHS());
CGF.PopConditionalTempDestruction();
RHSBlock = Builder.GetInsertBlock();
CGF.EmitBranch(ContBlock);
CGF.EmitBlock(ContBlock);
if (!LHS || !RHS) {
assert(E->getType()->isVoidType() && "Non-void value should have a value");
return 0;
}
// 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);
}
Value *CodeGenFunction::EmitShuffleVector(Value* V1, Value *V2, ...) {
assert(V1->getType() == V2->getType() &&
"Vector operands must be of the same type");
unsigned NumElements =
cast<llvm::VectorType>(V1->getType())->getNumElements();
va_list va;
va_start(va, V2);
llvm::SmallVector<llvm::Constant*, 16> Args;
for (unsigned i = 0; i < NumElements; i++) {
int n = va_arg(va, int);
assert(n >= 0 && n < (int)NumElements * 2 &&
"Vector shuffle index out of bounds!");
Args.push_back(llvm::ConstantInt::get(
llvm::Type::getInt32Ty(VMContext), n));
}
const char *Name = va_arg(va, const char *);
va_end(va);
llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements);
return Builder.CreateShuffleVector(V1, V2, Mask, Name);
}
llvm::Value *CodeGenFunction::EmitVector(llvm::Value * const *Vals,
unsigned NumVals, bool isSplat) {
llvm::Value *Vec
= llvm::UndefValue::get(llvm::VectorType::get(Vals[0]->getType(), NumVals));
for (unsigned i = 0, e = NumVals; i != e; ++i) {
llvm::Value *Val = isSplat ? Vals[0] : Vals[i];
llvm::Value *Idx = llvm::ConstantInt::get(
llvm::Type::getInt32Ty(VMContext), i);
Vec = Builder.CreateInsertElement(Vec, Val, Idx, "tmp");
}
return Vec;
}
Reference in New Issue View Git Blame Copy Permalink