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clang-1/CodeGen/CGExprScalar.cpp

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//===--- CGExprScalar.cpp - Emit LLVM Code for Scalar Exprs ---------------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Chris Lattner and 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/AST.h"
#include "llvm/Constants.h"
#include "llvm/Function.h"
#include "llvm/Intrinsics.h"
#include "llvm/Support/Compiler.h"
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;
llvm::LLVMFoldingBuilder &Builder;
public:
ScalarExprEmitter(CodeGenFunction &cgf) : CGF(cgf), Builder(CGF.Builder) {
}
//===--------------------------------------------------------------------===//
// Utilities
//===--------------------------------------------------------------------===//
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) {
// FIXME: Volatile
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().SourceMgr);
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(E->getValue());
}
Value *VisitFloatingLiteral(const FloatingLiteral *E) {
return llvm::ConstantFP::get(ConvertType(E->getType()), E->getValue());
}
Value *VisitCharacterLiteral(const CharacterLiteral *E) {
return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
}
Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) {
return llvm::ConstantInt::get(ConvertType(E->getType()),
CGF.getContext().typesAreCompatible(
E->getArgType1(), E->getArgType2()));
}
Value *VisitSizeOfAlignOfTypeExpr(const SizeOfAlignOfTypeExpr *E) {
return EmitSizeAlignOf(E->getArgumentType(), E->getType(), E->isSizeOf());
}
// l-values.
Value *VisitDeclRefExpr(DeclRefExpr *E) {
if (const EnumConstantDecl *EC = dyn_cast<EnumConstantDecl>(E->getDecl()))
return llvm::ConstantInt::get(EC->getInitVal());
return EmitLoadOfLValue(E);
}
Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E);
Value *VisitMemberExpr(Expr *E) { return EmitLoadOfLValue(E); }
Value *VisitOCUVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); }
Value *VisitStringLiteral(Expr *E) { return EmitLValue(E).getAddress(); }
Value *VisitPreDefinedExpr(Expr *E) { return EmitLValue(E).getAddress(); }
Value *VisitInitListExpr(InitListExpr *E) {
unsigned N = E->getNumInits();
QualType T = E->getInit(0)->getType();
Value *V = llvm::UndefValue::get(llvm::VectorType::get(ConvertType(T), N));
for (unsigned i = 0; i < N; ++i) {
Value *NewV = Visit(E->getInit(i));
Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i);
V = Builder.CreateInsertElement(V, NewV, Idx);
}
return V;
}
Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
return Visit(E->getInitializer());
}
Value *VisitImplicitCastExpr(const ImplicitCastExpr *E);
Value *VisitCastExpr(const CastExpr *E) {
return EmitCastExpr(E->getSubExpr(), E->getType());
}
Value *EmitCastExpr(const Expr *E, QualType T);
Value *VisitCallExpr(const CallExpr *E) {
return CGF.EmitCallExpr(E).getScalarVal();
}
Value *VisitStmtExpr(const StmtExpr *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) {
return Visit(E->getSubExpr());
}
Value *VisitUnaryMinus (const UnaryOperator *E);
Value *VisitUnaryNot (const UnaryOperator *E);
Value *VisitUnaryLNot (const UnaryOperator *E);
Value *VisitUnarySizeOf (const UnaryOperator *E) {
return EmitSizeAlignOf(E->getSubExpr()->getType(), E->getType(), true);
}
Value *VisitUnaryAlignOf (const UnaryOperator *E) {
return EmitSizeAlignOf(E->getSubExpr()->getType(), E->getType(), false);
}
Value *EmitSizeAlignOf(QualType TypeToSize, QualType RetType,
bool isSizeOf);
Value *VisitUnaryReal (const UnaryOperator *E);
Value *VisitUnaryImag (const UnaryOperator *E);
Value *VisitUnaryExtension(const UnaryOperator *E) {
return Visit(E->getSubExpr());
}
// Binary Operators.
Value *EmitMul(const BinOpInfo &Ops) {
return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul");
}
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);
// (Sub) - Sub is handled specially below for ptr-ptr subtract.
HANDLEBINOP(Shl);
HANDLEBINOP(Shr);
HANDLEBINOP(And);
HANDLEBINOP(Xor);
HANDLEBINOP(Or);
#undef HANDLEBINOP
Value *VisitBinSub(const BinaryOperator *E);
Value *VisitBinSubAssign(const CompoundAssignOperator *E) {
return EmitCompoundAssign(E, &ScalarExprEmitter::EmitSub);
}
// 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 *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");
}
assert((SrcType->isIntegerType() || SrcType->isPointerType()) &&
"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::Int1Ty) {
Value *Result = ZI->getOperand(0);
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 = SrcType.getCanonicalType();
DstType = DstType.getCanonicalType();
if (SrcType == DstType) return Src;
if (DstType->isVoidType()) return 0;
// 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.
if (isa<PointerType>(DstType)) {
// 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?");
return Builder.CreateIntToPtr(Src, DstTy, "conv");
}
if (isa<PointerType>(SrcType)) {
// Must be an ptr to int cast.
assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?");
return Builder.CreateIntToPtr(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 = cast<ComplexType>(SrcTy.getCanonicalType())->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) {
fprintf(stderr, "Unimplemented scalar expr!\n");
E->dump(CGF.getContext().SourceMgr);
if (E->getType()->isVoidType())
return 0;
return llvm::UndefValue::get(CGF.ConvertType(E->getType()));
}
Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
// 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());
// FIXME: Convert Idx to i32 type.
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()) {
// FIXME: For now we assume that all source arrays map to LLVM arrays. This
// will not true when we add support for VLAs.
Value *V = EmitLValue(Op).getAddress(); // Bitfields can't be arrays.
assert(isa<llvm::PointerType>(V->getType()) &&
isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType())
->getElementType()) &&
"Doesn't support VLAs yet!");
llvm::Constant *Idx0 = llvm::ConstantInt::get(llvm::Type::Int32Ty, 0);
llvm::Value *Ops[] = {Idx0, Idx0};
return Builder.CreateGEP(V, Ops, Ops+2, "arraydecay");
} else if (E->getType()->isReferenceType()) {
assert(cast<ReferenceType>(E->getType().getCanonicalType())->
getReferenceeType() ==
Op->getType().getCanonicalType() && "Incompatible types!");
return EmitLValue(Op).getAddress();
}
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) {
// Handle cases where the source is an non-complex type.
if (!E->getType()->isComplexType()) {
Value *Src = Visit(const_cast<Expr*>(E));
// Use EmitScalarConversion to perform the conversion.
return EmitScalarConversion(Src, E->getType(), DestTy);
}
// Handle cases where the source is a complex type.
return EmitComplexToScalarConversion(CGF.EmitComplexExpr(E), E->getType(),
DestTy);
}
Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) {
return CGF.EmitCompoundStmt(*E->getSubStmt(), true).getScalarVal();
}
//===----------------------------------------------------------------------===//
// Unary Operators
//===----------------------------------------------------------------------===//
Value *ScalarExprEmitter::VisitPrePostIncDec(const UnaryOperator *E,
bool isInc, bool isPre) {
LValue LV = EmitLValue(E->getSubExpr());
// FIXME: Handle volatile!
Value *InVal = CGF.EmitLoadOfLValue(LV, // false
E->getSubExpr()->getType()).getScalarVal();
int AmountVal = isInc ? 1 : -1;
Value *NextVal;
if (isa<llvm::PointerType>(InVal->getType())) {
// FIXME: This isn't right for VLAs.
NextVal = llvm::ConstantInt::get(llvm::Type::Int32Ty, AmountVal);
NextVal = Builder.CreateGEP(InVal, NextVal);
} else {
// Add the inc/dec to the real part.
if (isa<llvm::IntegerType>(InVal->getType()))
NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal);
else if (InVal->getType() == llvm::Type::FloatTy)
// FIXME: Handle long double.
NextVal = llvm::ConstantFP::get(InVal->getType(),
llvm::APFloat(static_cast<float>(AmountVal)));
else {
// FIXME: Handle long double.
assert(InVal->getType() == llvm::Type::DoubleTy);
NextVal = llvm::ConstantFP::get(InVal->getType(),
llvm::APFloat(static_cast<double>(AmountVal)));
}
NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec");
}
// Store the updated result through the lvalue.
CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV,
E->getSubExpr()->getType());
// 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) {
Value *Op = Visit(E->getSubExpr());
return Builder.CreateNeg(Op, "neg");
}
Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
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 int.
return Builder.CreateZExt(BoolVal, CGF.LLVMIntTy, "lnot.ext");
}
/// EmitSizeAlignOf - Return the size or alignment of the 'TypeToSize' type as
/// an integer (RetType).
Value *ScalarExprEmitter::EmitSizeAlignOf(QualType TypeToSize,
QualType RetType,bool isSizeOf){
/// FIXME: This doesn't handle VLAs yet!
std::pair<uint64_t, unsigned> Info =
CGF.getContext().getTypeInfo(TypeToSize, SourceLocation());
uint64_t Val = isSizeOf ? Info.first : Info.second;
Val /= 8; // Return size in bytes, not bits.
assert(RetType->isIntegerType() && "Result type must be an integer!");
uint32_t ResultWidth = static_cast<uint32_t>(
CGF.getContext().getTypeSize(RetType, SourceLocation()));
return llvm::ConstantInt::get(llvm::APInt(ResultWidth, Val));
}
Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) {
Expr *Op = E->getSubExpr();
if (Op->getType()->isComplexType())
return CGF.EmitComplexExpr(Op).first;
return Visit(Op);
}
Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) {
Expr *Op = E->getSubExpr();
if (Op->getType()->isComplexType())
return CGF.EmitComplexExpr(Op).second;
// __imag on a scalar returns zero. Emit it the subexpr to ensure side
// effects are evaluated.
CGF.EmitScalarExpr(Op);
return llvm::Constant::getNullValue(ConvertType(E->getType()));
}
//===----------------------------------------------------------------------===//
// Binary Operators
//===----------------------------------------------------------------------===//
BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) {
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 &)) {
QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType();
BinOpInfo OpInfo;
// Load the LHS and RHS operands.
LValue LHSLV = EmitLValue(E->getLHS());
OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy);
// Determine the computation type. If the RHS is complex, then this is one of
// the add/sub/mul/div operators. All of these operators can be computed in
// with just their real component even though the computation domain really is
// complex.
QualType ComputeType = E->getComputationType();
// If the computation type is complex, then the RHS is complex. Emit the RHS.
if (const ComplexType *CT = ComputeType->getAsComplexType()) {
ComputeType = CT->getElementType();
// Emit the RHS, only keeping the real component.
OpInfo.RHS = CGF.EmitComplexExpr(E->getRHS()).first;
RHSTy = RHSTy->getAsComplexType()->getElementType();
} else {
// Otherwise the RHS is a simple scalar value.
OpInfo.RHS = Visit(E->getRHS());
}
// Convert the LHS/RHS values to the computation type.
OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, ComputeType);
// Do not merge types for -= or += where the LHS is a pointer.
if (!(E->getOpcode() == BinaryOperator::SubAssign ||
E->getOpcode() == BinaryOperator::AddAssign) ||
// if (E->getOpcode() != BinaryOperator::SubAssign ||
!E->getLHS()->getType()->isPointerType()) {
OpInfo.RHS = EmitScalarConversion(OpInfo.RHS, RHSTy, ComputeType);
}
OpInfo.Ty = ComputeType;
OpInfo.E = E;
// Expand the binary operator.
Value *Result = (this->*Func)(OpInfo);
// Truncate the result back to the LHS type.
Result = EmitScalarConversion(Result, ComputeType, LHSTy);
// Store the result value into the LHS lvalue.
CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, E->getType());
return Result;
}
Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) {
if (Ops.LHS->getType()->isFloatingPoint())
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::EmitAdd(const BinOpInfo &Ops) {
if (!Ops.Ty->isPointerType())
return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add");
// FIXME: What about a pointer to a VLA?
if (isa<llvm::PointerType>(Ops.LHS->getType())) // pointer + int
return Builder.CreateGEP(Ops.LHS, Ops.RHS, "add.ptr");
// int + pointer
return Builder.CreateGEP(Ops.RHS, Ops.LHS, "add.ptr");
}
Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) {
if (!isa<llvm::PointerType>(Ops.LHS->getType()))
return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub");
// pointer - int
assert(!isa<llvm::PointerType>(Ops.RHS->getType()) &&
"ptr-ptr shouldn't get here");
// FIXME: The pointer could point to a VLA.
Value *NegatedRHS = Builder.CreateNeg(Ops.RHS, "sub.ptr.neg");
return Builder.CreateGEP(Ops.LHS, NegatedRHS, "sub.ptr");
}
Value *ScalarExprEmitter::VisitBinSub(const BinaryOperator *E) {
// "X - Y" is different from "X -= Y" in one case: when Y is a pointer. In
// the compound assignment case it is invalid, so just handle it here.
if (!E->getRHS()->getType()->isPointerType())
return EmitSub(EmitBinOps(E));
// pointer - pointer
Value *LHS = Visit(E->getLHS());
Value *RHS = Visit(E->getRHS());
const PointerType *LHSPtrType = E->getLHS()->getType()->getAsPointerType();
assert(LHSPtrType == E->getRHS()->getType()->getAsPointerType() &&
"Can't subtract different pointer types");
QualType LHSElementType = LHSPtrType->getPointeeType();
uint64_t ElementSize = CGF.getContext().getTypeSize(LHSElementType,
SourceLocation()) / 8;
const llvm::Type *ResultType = ConvertType(E->getType());
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");
// HACK: LLVM doesn't have an divide instruction that 'knows' there is no
// remainder. As such, we handle common power-of-two cases here to generate
// better code.
if (llvm::isPowerOf2_64(ElementSize)) {
Value *ShAmt =
llvm::ConstantInt::get(ResultType, llvm::Log2_64(ElementSize));
return Builder.CreateAShr(BytesBetween, ShAmt, "sub.ptr.shr");
}
// Otherwise, do a full sdiv.
Value *BytesPerElt = llvm::ConstantInt::get(ResultType, ElementSize);
return Builder.CreateSDiv(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) {
Value *Result;
QualType LHSTy = E->getLHS()->getType();
if (!LHSTy->isComplexType()) {
Value *LHS = Visit(E->getLHS());
Value *RHS = Visit(E->getRHS());
if (LHS->getType()->isFloatingPoint()) {
Result = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc,
LHS, RHS, "cmp");
} else if (LHSTy->isUnsignedIntegerType()) {
Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
LHS, RHS, "cmp");
} else {
// Signed integers and pointers.
Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc,
LHS, RHS, "cmp");
}
} 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 =
cast<ComplexType>(LHSTy.getCanonicalType())->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");
}
}
// ZExt result to int.
return Builder.CreateZExt(Result, CGF.LLVMIntTy, "cmp.ext");
}
Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) {
LValue LHS = EmitLValue(E->getLHS());
Value *RHS = Visit(E->getRHS());
// Store the value into the LHS.
// FIXME: Volatility!
CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType());
// Return the RHS.
return RHS;
}
Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) {
Value *LHSCond = CGF.EvaluateExprAsBool(E->getLHS());
llvm::BasicBlock *ContBlock = new llvm::BasicBlock("land_cont");
llvm::BasicBlock *RHSBlock = new llvm::BasicBlock("land_rhs");
llvm::BasicBlock *OrigBlock = Builder.GetInsertBlock();
Builder.CreateCondBr(LHSCond, RHSBlock, ContBlock);
CGF.EmitBlock(RHSBlock);
Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
// Reaquire the RHS block, as there may be subblocks inserted.
RHSBlock = Builder.GetInsertBlock();
CGF.EmitBlock(ContBlock);
// Create a PHI node. If we just evaluted the LHS condition, the result is
// false. If we evaluated both, the result is the RHS condition.
llvm::PHINode *PN = Builder.CreatePHI(llvm::Type::Int1Ty, "land");
PN->reserveOperandSpace(2);
PN->addIncoming(llvm::ConstantInt::getFalse(), OrigBlock);
PN->addIncoming(RHSCond, RHSBlock);
// ZExt result to int.
return Builder.CreateZExt(PN, CGF.LLVMIntTy, "land.ext");
}
Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) {
Value *LHSCond = CGF.EvaluateExprAsBool(E->getLHS());
llvm::BasicBlock *ContBlock = new llvm::BasicBlock("lor_cont");
llvm::BasicBlock *RHSBlock = new llvm::BasicBlock("lor_rhs");
llvm::BasicBlock *OrigBlock = Builder.GetInsertBlock();
Builder.CreateCondBr(LHSCond, ContBlock, RHSBlock);
CGF.EmitBlock(RHSBlock);
Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
// Reaquire the RHS block, as there may be subblocks inserted.
RHSBlock = Builder.GetInsertBlock();
CGF.EmitBlock(ContBlock);
// Create a PHI node. If we just evaluted the LHS condition, the result is
// true. If we evaluated both, the result is the RHS condition.
llvm::PHINode *PN = Builder.CreatePHI(llvm::Type::Int1Ty, "lor");
PN->reserveOperandSpace(2);
PN->addIncoming(llvm::ConstantInt::getTrue(), OrigBlock);
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());
return Visit(E->getRHS());
}
//===----------------------------------------------------------------------===//
// Other Operators
//===----------------------------------------------------------------------===//
Value *ScalarExprEmitter::
VisitConditionalOperator(const ConditionalOperator *E) {
llvm::BasicBlock *LHSBlock = new llvm::BasicBlock("cond.?");
llvm::BasicBlock *RHSBlock = new llvm::BasicBlock("cond.:");
llvm::BasicBlock *ContBlock = new llvm::BasicBlock("cond.cont");
Value *Cond = CGF.EvaluateExprAsBool(E->getCond());
Builder.CreateCondBr(Cond, LHSBlock, RHSBlock);
CGF.EmitBlock(LHSBlock);
// Handle the GNU extension for missing LHS.
Value *LHS = E->getLHS() ? Visit(E->getLHS()) : Cond;
Builder.CreateBr(ContBlock);
LHSBlock = Builder.GetInsertBlock();
CGF.EmitBlock(RHSBlock);
Value *RHS = Visit(E->getRHS());
Builder.CreateBr(ContBlock);
RHSBlock = Builder.GetInsertBlock();
CGF.EmitBlock(ContBlock);
// 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) {
// Emit the LHS or RHS as appropriate.
return Visit(E->isConditionTrue(CGF.getContext()) ? E->getLHS() : E->getRHS());
}
Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE)
{
llvm::Value *ArgValue = EmitLValue(VE->getSubExpr()).getAddress();
llvm::Value *V = Builder.CreateVAArg(ArgValue, ConvertType(VE->getType()));
return V;
}
//===----------------------------------------------------------------------===//
// Entry Point into this File
//===----------------------------------------------------------------------===//
/// EmitComplexExpr - Emit the computation of the specified expression of
/// complex type, ignoring the result.
Value *CodeGenFunction::EmitScalarExpr(const Expr *E) {
assert(E && !hasAggregateLLVMType(E->getType()) &&
"Invalid scalar expression to emit");
return ScalarExprEmitter(*this).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->isComplexType() && !hasAggregateLLVMType(DstTy) &&
"Invalid complex -> scalar conversion");
return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy,
DstTy);
}
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