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clang-1/lib/CodeGen/CGExprScalar.cpp

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C++
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//===--- CGExprScalar.cpp - Emit LLVM Code for Scalar Exprs ---------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This contains code to emit Expr nodes with scalar LLVM types as LLVM code.
//
//===----------------------------------------------------------------------===//
#include "clang/Frontend/CodeGenOptions.h"
#include "CodeGenFunction.h"
#include "CGCXXABI.h"
#include "CGObjCRuntime.h"
#include "CodeGenModule.h"
#include "CGDebugInfo.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/RecordLayout.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/Constants.h"
#include "llvm/Function.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Intrinsics.h"
#include "llvm/Module.h"
#include "llvm/Support/CFG.h"
#include "llvm/Target/TargetData.h"
#include <cstdarg>
using namespace clang;
using namespace CodeGen;
using llvm::Value;
//===----------------------------------------------------------------------===//
// Scalar Expression Emitter
//===----------------------------------------------------------------------===//
namespace {
struct BinOpInfo {
Value *LHS;
Value *RHS;
QualType Ty; // Computation Type.
BinaryOperator::Opcode Opcode; // Opcode of BinOp to perform
const Expr *E; // Entire expr, for error unsupported. May not be binop.
};
static bool MustVisitNullValue(const Expr *E) {
// If a null pointer expression's type is the C++0x nullptr_t, then
// it's not necessarily a simple constant and it must be evaluated
// for its potential side effects.
return E->getType()->isNullPtrType();
}
class ScalarExprEmitter
: public StmtVisitor<ScalarExprEmitter, Value*> {
CodeGenFunction &CGF;
CGBuilderTy &Builder;
bool IgnoreResultAssign;
llvm::LLVMContext &VMContext;
public:
ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false)
: CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira),
VMContext(cgf.getLLVMContext()) {
}
//===--------------------------------------------------------------------===//
// Utilities
//===--------------------------------------------------------------------===//
bool TestAndClearIgnoreResultAssign() {
bool I = IgnoreResultAssign;
IgnoreResultAssign = false;
return I;
}
llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); }
LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); }
LValue EmitCheckedLValue(const Expr *E) { return CGF.EmitCheckedLValue(E); }
Value *EmitLoadOfLValue(LValue LV) {
return CGF.EmitLoadOfLValue(LV).getScalarVal();
}
/// EmitLoadOfLValue - Given an expression with complex type that represents a
/// value l-value, this method emits the address of the l-value, then loads
/// and returns the result.
Value *EmitLoadOfLValue(const Expr *E) {
return EmitLoadOfLValue(EmitCheckedLValue(E));
}
/// EmitConversionToBool - Convert the specified expression value to a
/// boolean (i1) truth value. This is equivalent to "Val != 0".
Value *EmitConversionToBool(Value *Src, QualType DstTy);
/// EmitScalarConversion - Emit a conversion from the specified type to the
/// specified destination type, both of which are LLVM scalar types.
Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy);
/// EmitComplexToScalarConversion - Emit a conversion from the specified
/// complex type to the specified destination type, where the destination type
/// is an LLVM scalar type.
Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src,
QualType SrcTy, QualType DstTy);
/// EmitNullValue - Emit a value that corresponds to null for the given type.
Value *EmitNullValue(QualType Ty);
/// EmitFloatToBoolConversion - Perform an FP to boolean conversion.
Value *EmitFloatToBoolConversion(Value *V) {
// Compare against 0.0 for fp scalars.
llvm::Value *Zero = llvm::Constant::getNullValue(V->getType());
return Builder.CreateFCmpUNE(V, Zero, "tobool");
}
/// EmitPointerToBoolConversion - Perform a pointer to boolean conversion.
Value *EmitPointerToBoolConversion(Value *V) {
Value *Zero = llvm::ConstantPointerNull::get(
cast<llvm::PointerType>(V->getType()));
return Builder.CreateICmpNE(V, Zero, "tobool");
}
Value *EmitIntToBoolConversion(Value *V) {
// 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>(V)) {
if (ZI->getOperand(0)->getType() == Builder.getInt1Ty()) {
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;
}
}
return Builder.CreateIsNotNull(V, "tobool");
}
//===--------------------------------------------------------------------===//
// Visitor Methods
//===--------------------------------------------------------------------===//
Value *Visit(Expr *E) {
return StmtVisitor<ScalarExprEmitter, Value*>::Visit(E);
}
Value *VisitStmt(Stmt *S) {
S->dump(CGF.getContext().getSourceManager());
llvm_unreachable("Stmt can't have complex result type!");
}
Value *VisitExpr(Expr *S);
Value *VisitParenExpr(ParenExpr *PE) {
return Visit(PE->getSubExpr());
}
Value *VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) {
return Visit(E->getReplacement());
}
Value *VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
return Visit(GE->getResultExpr());
}
// Leaves.
Value *VisitIntegerLiteral(const IntegerLiteral *E) {
return Builder.getInt(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 *VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) {
return EmitNullValue(E->getType());
}
Value *VisitGNUNullExpr(const GNUNullExpr *E) {
return EmitNullValue(E->getType());
}
Value *VisitOffsetOfExpr(OffsetOfExpr *E);
Value *VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E);
Value *VisitAddrLabelExpr(const AddrLabelExpr *E) {
llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel());
return Builder.CreateBitCast(V, ConvertType(E->getType()));
}
Value *VisitSizeOfPackExpr(SizeOfPackExpr *E) {
return llvm::ConstantInt::get(ConvertType(E->getType()),E->getPackLength());
}
Value *VisitPseudoObjectExpr(PseudoObjectExpr *E) {
return CGF.EmitPseudoObjectRValue(E).getScalarVal();
}
Value *VisitOpaqueValueExpr(OpaqueValueExpr *E) {
if (E->isGLValue())
return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E));
// Otherwise, assume the mapping is the scalar directly.
return CGF.getOpaqueRValueMapping(E).getScalarVal();
}
// l-values.
Value *VisitDeclRefExpr(DeclRefExpr *E) {
Expr::EvalResult Result;
if (!E->EvaluateAsRValue(Result, CGF.getContext()))
return EmitLoadOfLValue(E);
assert(!Result.HasSideEffects && "Constant declref with side-effect?!");
llvm::Constant *C;
if (Result.Val.isInt())
C = Builder.getInt(Result.Val.getInt());
else if (Result.Val.isFloat())
C = llvm::ConstantFP::get(VMContext, Result.Val.getFloat());
else
return EmitLoadOfLValue(E);
// Make sure we emit a debug reference to the global variable.
if (VarDecl *VD = dyn_cast<VarDecl>(E->getDecl())) {
if (!CGF.getContext().DeclMustBeEmitted(VD))
CGF.EmitDeclRefExprDbgValue(E, C);
} else if (isa<EnumConstantDecl>(E->getDecl())) {
CGF.EmitDeclRefExprDbgValue(E, C);
}
return C;
}
Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) {
return CGF.EmitObjCSelectorExpr(E);
}
Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) {
return CGF.EmitObjCProtocolExpr(E);
}
Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
return EmitLoadOfLValue(E);
}
Value *VisitObjCMessageExpr(ObjCMessageExpr *E) {
if (E->getMethodDecl() &&
E->getMethodDecl()->getResultType()->isReferenceType())
return EmitLoadOfLValue(E);
return CGF.EmitObjCMessageExpr(E).getScalarVal();
}
Value *VisitObjCIsaExpr(ObjCIsaExpr *E) {
LValue LV = CGF.EmitObjCIsaExpr(E);
Value *V = CGF.EmitLoadOfLValue(LV).getScalarVal();
return V;
}
Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E);
Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E);
Value *VisitMemberExpr(MemberExpr *E);
Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); }
Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
return EmitLoadOfLValue(E);
}
Value *VisitInitListExpr(InitListExpr *E);
Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) {
return CGF.CGM.EmitNullConstant(E->getType());
}
Value *VisitExplicitCastExpr(ExplicitCastExpr *E) {
if (E->getType()->isVariablyModifiedType())
CGF.EmitVariablyModifiedType(E->getType());
return VisitCastExpr(E);
}
Value *VisitCastExpr(CastExpr *E);
Value *VisitCallExpr(const CallExpr *E) {
if (E->getCallReturnType()->isReferenceType())
return EmitLoadOfLValue(E);
return CGF.EmitCallExpr(E).getScalarVal();
}
Value *VisitStmtExpr(const StmtExpr *E);
Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E);
// Unary Operators.
Value *VisitUnaryPostDec(const UnaryOperator *E) {
LValue LV = EmitLValue(E->getSubExpr());
return EmitScalarPrePostIncDec(E, LV, false, false);
}
Value *VisitUnaryPostInc(const UnaryOperator *E) {
LValue LV = EmitLValue(E->getSubExpr());
return EmitScalarPrePostIncDec(E, LV, true, false);
}
Value *VisitUnaryPreDec(const UnaryOperator *E) {
LValue LV = EmitLValue(E->getSubExpr());
return EmitScalarPrePostIncDec(E, LV, false, true);
}
Value *VisitUnaryPreInc(const UnaryOperator *E) {
LValue LV = EmitLValue(E->getSubExpr());
return EmitScalarPrePostIncDec(E, LV, true, true);
}
llvm::Value *EmitAddConsiderOverflowBehavior(const UnaryOperator *E,
llvm::Value *InVal,
llvm::Value *NextVal,
bool IsInc);
llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
bool isInc, bool isPre);
Value *VisitUnaryAddrOf(const UnaryOperator *E) {
if (isa<MemberPointerType>(E->getType())) // never sugared
return CGF.CGM.getMemberPointerConstant(E);
return EmitLValue(E->getSubExpr()).getAddress();
}
Value *VisitUnaryDeref(const UnaryOperator *E) {
if (E->getType()->isVoidType())
return Visit(E->getSubExpr()); // the actual value should be unused
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());
}
// C++
Value *VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E) {
return EmitLoadOfLValue(E);
}
Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
return Visit(DAE->getExpr());
}
Value *VisitCXXThisExpr(CXXThisExpr *TE) {
return CGF.LoadCXXThis();
}
Value *VisitExprWithCleanups(ExprWithCleanups *E) {
CGF.enterFullExpression(E);
CodeGenFunction::RunCleanupsScope Scope(CGF);
return Visit(E->getSubExpr());
}
Value *VisitCXXNewExpr(const CXXNewExpr *E) {
return CGF.EmitCXXNewExpr(E);
}
Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) {
CGF.EmitCXXDeleteExpr(E);
return 0;
}
Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) {
return Builder.getInt1(E->getValue());
}
Value *VisitBinaryTypeTraitExpr(const BinaryTypeTraitExpr *E) {
return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
}
Value *VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) {
return llvm::ConstantInt::get(Builder.getInt32Ty(), E->getValue());
}
Value *VisitExpressionTraitExpr(const ExpressionTraitExpr *E) {
return llvm::ConstantInt::get(Builder.getInt1Ty(), E->getValue());
}
Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) {
// C++ [expr.pseudo]p1:
// The result shall only be used as the operand for the function call
// operator (), and the result of such a call has type void. The only
// effect is the evaluation of the postfix-expression before the dot or
// arrow.
CGF.EmitScalarExpr(E->getBase());
return 0;
}
Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) {
return EmitNullValue(E->getType());
}
Value *VisitCXXThrowExpr(const CXXThrowExpr *E) {
CGF.EmitCXXThrowExpr(E);
return 0;
}
Value *VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) {
return Builder.getInt1(E->getValue());
}
// Binary Operators.
Value *EmitMul(const BinOpInfo &Ops) {
if (Ops.Ty->isSignedIntegerOrEnumerationType()) {
switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) {
case LangOptions::SOB_Undefined:
return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul");
case LangOptions::SOB_Defined:
return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul");
case LangOptions::SOB_Trapping:
return EmitOverflowCheckedBinOp(Ops);
}
}
if (Ops.LHS->getType()->isFPOrFPVectorTy())
return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul");
return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul");
}
bool isTrapvOverflowBehavior() {
return CGF.getContext().getLangOptions().getSignedOverflowBehavior()
== LangOptions::SOB_Trapping;
}
/// Create a binary op that checks for overflow.
/// Currently only supports +, - and *.
Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops);
// Emit the overflow BB when -ftrapv option is activated.
void EmitOverflowBB(llvm::BasicBlock *overflowBB) {
Builder.SetInsertPoint(overflowBB);
llvm::Function *Trap = CGF.CGM.getIntrinsic(llvm::Intrinsic::trap);
Builder.CreateCall(Trap);
Builder.CreateUnreachable();
}
// Check for undefined division and modulus behaviors.
void EmitUndefinedBehaviorIntegerDivAndRemCheck(const BinOpInfo &Ops,
llvm::Value *Zero,bool isDiv);
Value *EmitDiv(const BinOpInfo &Ops);
Value *EmitRem(const BinOpInfo &Ops);
Value *EmitAdd(const BinOpInfo &Ops);
Value *EmitSub(const BinOpInfo &Ops);
Value *EmitShl(const BinOpInfo &Ops);
Value *EmitShr(const BinOpInfo &Ops);
Value *EmitAnd(const BinOpInfo &Ops) {
return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and");
}
Value *EmitXor(const BinOpInfo &Ops) {
return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor");
}
Value *EmitOr (const BinOpInfo &Ops) {
return Builder.CreateOr(Ops.LHS, Ops.RHS, "or");
}
BinOpInfo EmitBinOps(const BinaryOperator *E);
LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
Value *(ScalarExprEmitter::*F)(const BinOpInfo &),
Value *&Result);
Value *EmitCompoundAssign(const CompoundAssignOperator *E,
Value *(ScalarExprEmitter::*F)(const BinOpInfo &));
// Binary operators and binary compound assignment operators.
#define HANDLEBINOP(OP) \
Value *VisitBin ## OP(const BinaryOperator *E) { \
return Emit ## OP(EmitBinOps(E)); \
} \
Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \
return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \
}
HANDLEBINOP(Mul)
HANDLEBINOP(Div)
HANDLEBINOP(Rem)
HANDLEBINOP(Add)
HANDLEBINOP(Sub)
HANDLEBINOP(Shl)
HANDLEBINOP(Shr)
HANDLEBINOP(And)
HANDLEBINOP(Xor)
HANDLEBINOP(Or)
#undef HANDLEBINOP
// Comparisons.
Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc,
unsigned SICmpOpc, unsigned FCmpOpc);
#define VISITCOMP(CODE, UI, SI, FP) \
Value *VisitBin##CODE(const BinaryOperator *E) { \
return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \
llvm::FCmpInst::FP); }
VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT)
VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT)
VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE)
VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE)
VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ)
VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE)
#undef VISITCOMP
Value *VisitBinAssign (const BinaryOperator *E);
Value *VisitBinLAnd (const BinaryOperator *E);
Value *VisitBinLOr (const BinaryOperator *E);
Value *VisitBinComma (const BinaryOperator *E);
Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); }
Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); }
// Other Operators.
Value *VisitBlockExpr(const BlockExpr *BE);
Value *VisitAbstractConditionalOperator(const AbstractConditionalOperator *);
Value *VisitChooseExpr(ChooseExpr *CE);
Value *VisitVAArgExpr(VAArgExpr *VE);
Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) {
return CGF.EmitObjCStringLiteral(E);
}
Value *VisitAsTypeExpr(AsTypeExpr *CE);
Value *VisitAtomicExpr(AtomicExpr *AE);
};
} // 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())
return EmitFloatToBoolConversion(Src);
if (const MemberPointerType *MPT = dyn_cast<MemberPointerType>(SrcType))
return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, Src, MPT);
assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) &&
"Unknown scalar type to convert");
if (isa<llvm::IntegerType>(Src->getType()))
return EmitIntToBoolConversion(Src);
assert(isa<llvm::PointerType>(Src->getType()));
return EmitPointerToBoolConversion(Src);
}
/// 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::Type *SrcTy = Src->getType();
// Floating casts might be a bit special: if we're doing casts to / from half
// FP, we should go via special intrinsics.
if (SrcType->isHalfType()) {
Src = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16), Src);
SrcType = CGF.getContext().FloatTy;
SrcTy = llvm::Type::getFloatTy(VMContext);
}
// Handle conversions to bool first, they are special: comparisons against 0.
if (DstType->isBooleanType())
return EmitConversionToBool(Src, SrcType);
llvm::Type *DstTy = ConvertType(DstType);
// Ignore conversions like int -> uint.
if (SrcTy == 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>(SrcTy))
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.
llvm::Type *MiddleTy = CGF.IntPtrTy;
bool InputSigned = SrcType->isSignedIntegerOrEnumerationType();
llvm::Value* IntResult =
Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv");
// Then, cast to pointer.
return Builder.CreateIntToPtr(IntResult, DstTy, "conv");
}
if (isa<llvm::PointerType>(SrcTy)) {
// Must be an ptr to int cast.
assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?");
return Builder.CreatePtrToInt(Src, DstTy, "conv");
}
// A scalar can be splatted to an extended vector of the same element type
if (DstType->isExtVectorType() && !SrcType->isVectorType()) {
// Cast the scalar to element type
QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType();
llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy);
// Insert the element in element zero of an undef vector
llvm::Value *UnV = llvm::UndefValue::get(DstTy);
llvm::Value *Idx = Builder.getInt32(0);
UnV = Builder.CreateInsertElement(UnV, Elt, Idx);
// Splat the element across to all elements
SmallVector<llvm::Constant*, 16> Args;
unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements();
for (unsigned i = 0; i != NumElements; ++i)
Args.push_back(Builder.getInt32(0));
llvm::Constant *Mask = llvm::ConstantVector::get(Args);
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>(SrcTy) ||
isa<llvm::VectorType>(DstTy))
return Builder.CreateBitCast(Src, DstTy, "conv");
// Finally, we have the arithmetic types: real int/float.
Value *Res = NULL;
llvm::Type *ResTy = DstTy;
// Cast to half via float
if (DstType->isHalfType())
DstTy = llvm::Type::getFloatTy(VMContext);
if (isa<llvm::IntegerType>(SrcTy)) {
bool InputSigned = SrcType->isSignedIntegerOrEnumerationType();
if (isa<llvm::IntegerType>(DstTy))
Res = Builder.CreateIntCast(Src, DstTy, InputSigned, "conv");
else if (InputSigned)
Res = Builder.CreateSIToFP(Src, DstTy, "conv");
else
Res = Builder.CreateUIToFP(Src, DstTy, "conv");
} else if (isa<llvm::IntegerType>(DstTy)) {
assert(SrcTy->isFloatingPointTy() && "Unknown real conversion");
if (DstType->isSignedIntegerOrEnumerationType())
Res = Builder.CreateFPToSI(Src, DstTy, "conv");
else
Res = Builder.CreateFPToUI(Src, DstTy, "conv");
} else {
assert(SrcTy->isFloatingPointTy() && DstTy->isFloatingPointTy() &&
"Unknown real conversion");
if (DstTy->getTypeID() < SrcTy->getTypeID())
Res = Builder.CreateFPTrunc(Src, DstTy, "conv");
else
Res = Builder.CreateFPExt(Src, DstTy, "conv");
}
if (DstTy != ResTy) {
assert(ResTy->isIntegerTy(16) && "Only half FP requires extra conversion");
Res = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16), Res);
}
return Res;
}
/// EmitComplexToScalarConversion - Emit a conversion from the specified complex
/// type to the specified destination type, where the destination type is an
/// LLVM scalar type.
Value *ScalarExprEmitter::
EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src,
QualType SrcTy, QualType DstTy) {
// Get the source element type.
SrcTy = SrcTy->getAs<ComplexType>()->getElementType();
// Handle conversions to bool first, they are special: comparisons against 0.
if (DstTy->isBooleanType()) {
// Complex != 0 -> (Real != 0) | (Imag != 0)
Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy);
Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy);
return Builder.CreateOr(Src.first, Src.second, "tobool");
}
// C99 6.3.1.7p2: "When a value of complex type is converted to a real type,
// the imaginary part of the complex value is discarded and the value of the
// real part is converted according to the conversion rules for the
// corresponding real type.
return EmitScalarConversion(Src.first, SrcTy, DstTy);
}
Value *ScalarExprEmitter::EmitNullValue(QualType Ty) {
if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>())
return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT);
return llvm::Constant::getNullValue(ConvertType(Ty));
}
//===----------------------------------------------------------------------===//
// Visitor Methods
//===----------------------------------------------------------------------===//
Value *ScalarExprEmitter::VisitExpr(Expr *E) {
CGF.ErrorUnsupported(E, "scalar expression");
if (E->getType()->isVoidType())
return 0;
return llvm::UndefValue::get(CGF.ConvertType(E->getType()));
}
Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) {
// Vector Mask Case
if (E->getNumSubExprs() == 2 ||
(E->getNumSubExprs() == 3 && E->getExpr(2)->getType()->isVectorType())) {
Value *LHS = CGF.EmitScalarExpr(E->getExpr(0));
Value *RHS = CGF.EmitScalarExpr(E->getExpr(1));
Value *Mask;
llvm::VectorType *LTy = cast<llvm::VectorType>(LHS->getType());
unsigned LHSElts = LTy->getNumElements();
if (E->getNumSubExprs() == 3) {
Mask = CGF.EmitScalarExpr(E->getExpr(2));
// Shuffle LHS & RHS into one input vector.
SmallVector<llvm::Constant*, 32> concat;
for (unsigned i = 0; i != LHSElts; ++i) {
concat.push_back(Builder.getInt32(2*i));
concat.push_back(Builder.getInt32(2*i+1));
}
Value* CV = llvm::ConstantVector::get(concat);
LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat");
LHSElts *= 2;
} else {
Mask = RHS;
}
llvm::VectorType *MTy = cast<llvm::VectorType>(Mask->getType());
llvm::Constant* EltMask;
// Treat vec3 like vec4.
if ((LHSElts == 6) && (E->getNumSubExprs() == 3))
EltMask = llvm::ConstantInt::get(MTy->getElementType(),
(1 << llvm::Log2_32(LHSElts+2))-1);
else if ((LHSElts == 3) && (E->getNumSubExprs() == 2))
EltMask = llvm::ConstantInt::get(MTy->getElementType(),
(1 << llvm::Log2_32(LHSElts+1))-1);
else
EltMask = llvm::ConstantInt::get(MTy->getElementType(),
(1 << llvm::Log2_32(LHSElts))-1);
// Mask off the high bits of each shuffle index.
SmallVector<llvm::Constant *, 32> MaskV;
for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i)
MaskV.push_back(EltMask);
Value* MaskBits = llvm::ConstantVector::get(MaskV);
Mask = Builder.CreateAnd(Mask, MaskBits, "mask");
// newv = undef
// mask = mask & maskbits
// for each elt
// n = extract mask i
// x = extract val n
// newv = insert newv, x, i
llvm::VectorType *RTy = llvm::VectorType::get(LTy->getElementType(),
MTy->getNumElements());
Value* NewV = llvm::UndefValue::get(RTy);
for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) {
Value *Indx = Builder.getInt32(i);
Indx = Builder.CreateExtractElement(Mask, Indx, "shuf_idx");
Indx = Builder.CreateZExt(Indx, CGF.Int32Ty, "idx_zext");
// Handle vec3 special since the index will be off by one for the RHS.
if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) {
Value *cmpIndx, *newIndx;
cmpIndx = Builder.CreateICmpUGT(Indx, Builder.getInt32(3),
"cmp_shuf_idx");
newIndx = Builder.CreateSub(Indx, Builder.getInt32(1), "shuf_idx_adj");
Indx = Builder.CreateSelect(cmpIndx, newIndx, Indx, "sel_shuf_idx");
}
Value *VExt = Builder.CreateExtractElement(LHS, Indx, "shuf_elt");
NewV = Builder.CreateInsertElement(NewV, VExt, Indx, "shuf_ins");
}
return NewV;
}
Value* V1 = CGF.EmitScalarExpr(E->getExpr(0));
Value* V2 = CGF.EmitScalarExpr(E->getExpr(1));
// Handle vec3 special since the index will be off by one for the RHS.
llvm::VectorType *VTy = cast<llvm::VectorType>(V1->getType());
SmallVector<llvm::Constant*, 32> indices;
for (unsigned i = 2; i < E->getNumSubExprs(); i++) {
unsigned Idx = E->getShuffleMaskIdx(CGF.getContext(), i-2);
if (VTy->getNumElements() == 3 && Idx > 3)
Idx -= 1;
indices.push_back(Builder.getInt32(Idx));
}
Value *SV = llvm::ConstantVector::get(indices);
return Builder.CreateShuffleVector(V1, V2, SV, "shuffle");
}
Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) {
Expr::EvalResult Result;
if (E->EvaluateAsRValue(Result, CGF.getContext()) && Result.Val.isInt()) {
if (E->isArrow())
CGF.EmitScalarExpr(E->getBase());
else
EmitLValue(E->getBase());
return Builder.getInt(Result.Val.getInt());
}
// Emit debug info for aggregate now, if it was delayed to reduce
// debug info size.
CGDebugInfo *DI = CGF.getDebugInfo();
if (DI && CGF.CGM.getCodeGenOpts().LimitDebugInfo) {
QualType PQTy = E->getBase()->IgnoreParenImpCasts()->getType();
if (const PointerType * PTy = dyn_cast<PointerType>(PQTy))
if (FieldDecl *M = dyn_cast<FieldDecl>(E->getMemberDecl()))
DI->getOrCreateRecordType(PTy->getPointeeType(),
M->getParent()->getLocation());
}
return EmitLoadOfLValue(E);
}
Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
TestAndClearIgnoreResultAssign();
// Emit subscript expressions in rvalue context's. For most cases, this just
// loads the lvalue formed by the subscript expr. However, we have to be
// careful, because the base of a vector subscript is occasionally an rvalue,
// so we can't get it as an lvalue.
if (!E->getBase()->getType()->isVectorType())
return EmitLoadOfLValue(E);
// Handle the vector case. The base must be a vector, the index must be an
// integer value.
Value *Base = Visit(E->getBase());
Value *Idx = Visit(E->getIdx());
bool IdxSigned = E->getIdx()->getType()->isSignedIntegerOrEnumerationType();
Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vecidxcast");
return Builder.CreateExtractElement(Base, Idx, "vecext");
}
static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx,
unsigned Off, llvm::Type *I32Ty) {
int MV = SVI->getMaskValue(Idx);
if (MV == -1)
return llvm::UndefValue::get(I32Ty);
return llvm::ConstantInt::get(I32Ty, Off+MV);
}
Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) {
bool Ignore = TestAndClearIgnoreResultAssign();
(void)Ignore;
assert (Ignore == false && "init list ignored");
unsigned NumInitElements = E->getNumInits();
if (E->hadArrayRangeDesignator())
CGF.ErrorUnsupported(E, "GNU array range designator extension");
llvm::VectorType *VType =
dyn_cast<llvm::VectorType>(ConvertType(E->getType()));
if (!VType) {
if (NumInitElements == 0) {
// C++11 value-initialization for the scalar.
return EmitNullValue(E->getType());
}
// We have a scalar in braces. Just use the first element.
return Visit(E->getInit(0));
}
unsigned ResElts = VType->getNumElements();
// Loop over initializers collecting the Value for each, and remembering
// whether the source was swizzle (ExtVectorElementExpr). This will allow
// us to fold the shuffle for the swizzle into the shuffle for the vector
// initializer, since LLVM optimizers generally do not want to touch
// shuffles.
unsigned CurIdx = 0;
bool VIsUndefShuffle = false;
llvm::Value *V = llvm::UndefValue::get(VType);
for (unsigned i = 0; i != NumInitElements; ++i) {
Expr *IE = E->getInit(i);
Value *Init = Visit(IE);
SmallVector<llvm::Constant*, 16> Args;
llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType());
// Handle scalar elements. If the scalar initializer is actually one
// element of a different vector of the same width, use shuffle instead of
// extract+insert.
if (!VVT) {
if (isa<ExtVectorElementExpr>(IE)) {
llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init);
if (EI->getVectorOperandType()->getNumElements() == ResElts) {
llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand());
Value *LHS = 0, *RHS = 0;
if (CurIdx == 0) {
// insert into undef -> shuffle (src, undef)
Args.push_back(C);
for (unsigned j = 1; j != ResElts; ++j)
Args.push_back(llvm::UndefValue::get(CGF.Int32Ty));
LHS = EI->getVectorOperand();
RHS = V;
VIsUndefShuffle = true;
} else if (VIsUndefShuffle) {
// insert into undefshuffle && size match -> shuffle (v, src)
llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V);
for (unsigned j = 0; j != CurIdx; ++j)
Args.push_back(getMaskElt(SVV, j, 0, CGF.Int32Ty));
Args.push_back(Builder.getInt32(ResElts + C->getZExtValue()));
for (unsigned j = CurIdx + 1; j != ResElts; ++j)
Args.push_back(llvm::UndefValue::get(CGF.Int32Ty));
LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0);
RHS = EI->getVectorOperand();
VIsUndefShuffle = false;
}
if (!Args.empty()) {
llvm::Constant *Mask = llvm::ConstantVector::get(Args);
V = Builder.CreateShuffleVector(LHS, RHS, Mask);
++CurIdx;
continue;
}
}
}
V = Builder.CreateInsertElement(V, Init, Builder.getInt32(CurIdx),
"vecinit");
VIsUndefShuffle = false;
++CurIdx;
continue;
}
unsigned InitElts = VVT->getNumElements();
// If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's
// input is the same width as the vector being constructed, generate an
// optimized shuffle of the swizzle input into the result.
unsigned Offset = (CurIdx == 0) ? 0 : ResElts;
if (isa<ExtVectorElementExpr>(IE)) {
llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init);
Value *SVOp = SVI->getOperand(0);
llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType());
if (OpTy->getNumElements() == ResElts) {
for (unsigned j = 0; j != CurIdx; ++j) {
// If the current vector initializer is a shuffle with undef, merge
// this shuffle directly into it.
if (VIsUndefShuffle) {
Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0,
CGF.Int32Ty));
} else {
Args.push_back(Builder.getInt32(j));
}
}
for (unsigned j = 0, je = InitElts; j != je; ++j)
Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty));
for (unsigned j = CurIdx + InitElts; j != ResElts; ++j)
Args.push_back(llvm::UndefValue::get(CGF.Int32Ty));
if (VIsUndefShuffle)
V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0);
Init = SVOp;
}
}
// Extend init to result vector length, and then shuffle its contribution
// to the vector initializer into V.
if (Args.empty()) {
for (unsigned j = 0; j != InitElts; ++j)
Args.push_back(Builder.getInt32(j));
for (unsigned j = InitElts; j != ResElts; ++j)
Args.push_back(llvm::UndefValue::get(CGF.Int32Ty));
llvm::Constant *Mask = llvm::ConstantVector::get(Args);
Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT),
Mask, "vext");
Args.clear();
for (unsigned j = 0; j != CurIdx; ++j)
Args.push_back(Builder.getInt32(j));
for (unsigned j = 0; j != InitElts; ++j)
Args.push_back(Builder.getInt32(j+Offset));
for (unsigned j = CurIdx + InitElts; j != ResElts; ++j)
Args.push_back(llvm::UndefValue::get(CGF.Int32Ty));
}
// If V is undef, make sure it ends up on the RHS of the shuffle to aid
// merging subsequent shuffles into this one.
if (CurIdx == 0)
std::swap(V, Init);
llvm::Constant *Mask = llvm::ConstantVector::get(Args);
V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit");
VIsUndefShuffle = isa<llvm::UndefValue>(Init);
CurIdx += InitElts;
}
// FIXME: evaluate codegen vs. shuffling against constant null vector.
// Emit remaining default initializers.
llvm::Type *EltTy = VType->getElementType();
// Emit remaining default initializers
for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) {
Value *Idx = Builder.getInt32(CurIdx);
llvm::Value *Init = llvm::Constant::getNullValue(EltTy);
V = Builder.CreateInsertElement(V, Init, Idx, "vecinit");
}
return V;
}
static bool ShouldNullCheckClassCastValue(const CastExpr *CE) {
const Expr *E = CE->getSubExpr();
if (CE->getCastKind() == CK_UncheckedDerivedToBase)
return false;
if (isa<CXXThisExpr>(E)) {
// We always assume that 'this' is never null.
return false;
}
if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) {
// And that glvalue casts are never null.
if (ICE->getValueKind() != VK_RValue)
return false;
}
return true;
}
// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts
// have to handle a more broad range of conversions than explicit casts, as they
// handle things like function to ptr-to-function decay etc.
Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) {
Expr *E = CE->getSubExpr();
QualType DestTy = CE->getType();
CastKind Kind = CE->getCastKind();
if (!DestTy->isVoidType())
TestAndClearIgnoreResultAssign();
// Since almost all cast kinds apply to scalars, this switch doesn't have
// a default case, so the compiler will warn on a missing case. The cases
// are in the same order as in the CastKind enum.
switch (Kind) {
case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!");
case CK_LValueBitCast:
case CK_ObjCObjectLValueCast: {
Value *V = EmitLValue(E).getAddress();
V = Builder.CreateBitCast(V,
ConvertType(CGF.getContext().getPointerType(DestTy)));
return EmitLoadOfLValue(CGF.MakeAddrLValue(V, DestTy));
}
case CK_CPointerToObjCPointerCast:
case CK_BlockPointerToObjCPointerCast:
case CK_AnyPointerToBlockPointerCast:
case CK_BitCast: {
Value *Src = Visit(const_cast<Expr*>(E));
return Builder.CreateBitCast(Src, ConvertType(DestTy));
}
case CK_NoOp:
case CK_UserDefinedConversion:
return Visit(const_cast<Expr*>(E));
case CK_BaseToDerived: {
const CXXRecordDecl *DerivedClassDecl =
DestTy->getCXXRecordDeclForPointerType();
return CGF.GetAddressOfDerivedClass(Visit(E), DerivedClassDecl,
CE->path_begin(), CE->path_end(),
ShouldNullCheckClassCastValue(CE));
}
case CK_UncheckedDerivedToBase:
case CK_DerivedToBase: {
const RecordType *DerivedClassTy =
E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>();
CXXRecordDecl *DerivedClassDecl =
cast<CXXRecordDecl>(DerivedClassTy->getDecl());
return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl,
CE->path_begin(), CE->path_end(),
ShouldNullCheckClassCastValue(CE));
}
case CK_Dynamic: {
Value *V = Visit(const_cast<Expr*>(E));
const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE);
return CGF.EmitDynamicCast(V, DCE);
}
case CK_ArrayToPointerDecay: {
assert(E->getType()->isArrayType() &&
"Array to pointer decay must have array source type!");
Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays.
// Note that VLA pointers are always decayed, so we don't need to do
// anything here.
if (!E->getType()->isVariableArrayType()) {
assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer");
assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType())
->getElementType()) &&
"Expected pointer to array");
V = Builder.CreateStructGEP(V, 0, "arraydecay");
}
// Make sure the array decay ends up being the right type. This matters if
// the array type was of an incomplete type.
return CGF.Builder.CreateBitCast(V, ConvertType(CE->getType()));
}
case CK_FunctionToPointerDecay:
return EmitLValue(E).getAddress();
case CK_NullToPointer:
if (MustVisitNullValue(E))
(void) Visit(E);
return llvm::ConstantPointerNull::get(
cast<llvm::PointerType>(ConvertType(DestTy)));
case CK_NullToMemberPointer: {
if (MustVisitNullValue(E))
(void) Visit(E);
const MemberPointerType *MPT = CE->getType()->getAs<MemberPointerType>();
return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT);
}
case CK_BaseToDerivedMemberPointer:
case CK_DerivedToBaseMemberPointer: {
Value *Src = Visit(E);
// Note that the AST doesn't distinguish between checked and
// unchecked member pointer conversions, so we always have to
// implement checked conversions here. This is inefficient when
// actual control flow may be required in order to perform the
// check, which it is for data member pointers (but not member
// function pointers on Itanium and ARM).
return CGF.CGM.getCXXABI().EmitMemberPointerConversion(CGF, CE, Src);
}
case CK_ARCProduceObject:
return CGF.EmitARCRetainScalarExpr(E);
case CK_ARCConsumeObject:
return CGF.EmitObjCConsumeObject(E->getType(), Visit(E));
case CK_ARCReclaimReturnedObject: {
llvm::Value *value = Visit(E);
value = CGF.EmitARCRetainAutoreleasedReturnValue(value);
return CGF.EmitObjCConsumeObject(E->getType(), value);
}
case CK_ARCExtendBlockObject:
return CGF.EmitARCExtendBlockObject(E);
case CK_FloatingRealToComplex:
case CK_FloatingComplexCast:
case CK_IntegralRealToComplex:
case CK_IntegralComplexCast:
case CK_IntegralComplexToFloatingComplex:
case CK_FloatingComplexToIntegralComplex:
case CK_ConstructorConversion:
case CK_ToUnion:
llvm_unreachable("scalar cast to non-scalar value");
break;
case CK_LValueToRValue:
assert(CGF.getContext().hasSameUnqualifiedType(E->getType(), DestTy));
assert(E->isGLValue() && "lvalue-to-rvalue applied to r-value!");
return Visit(const_cast<Expr*>(E));
case CK_IntegralToPointer: {
Value *Src = Visit(const_cast<Expr*>(E));
// First, convert to the correct width so that we control the kind of
// extension.
llvm::Type *MiddleTy = CGF.IntPtrTy;
bool InputSigned = E->getType()->isSignedIntegerOrEnumerationType();
llvm::Value* IntResult =
Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv");
return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy));
}
case CK_PointerToIntegral:
assert(!DestTy->isBooleanType() && "bool should use PointerToBool");
return Builder.CreatePtrToInt(Visit(E), ConvertType(DestTy));
case CK_ToVoid: {
CGF.EmitIgnoredExpr(E);
return 0;
}
case CK_VectorSplat: {
llvm::Type *DstTy = ConvertType(DestTy);
Value *Elt = Visit(const_cast<Expr*>(E));
// Insert the element in element zero of an undef vector
llvm::Value *UnV = llvm::UndefValue::get(DstTy);
llvm::Value *Idx = Builder.getInt32(0);
UnV = Builder.CreateInsertElement(UnV, Elt, Idx);
// Splat the element across to all elements
SmallVector<llvm::Constant*, 16> Args;
unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements();
llvm::Constant *Zero = Builder.getInt32(0);
for (unsigned i = 0; i < NumElements; i++)
Args.push_back(Zero);
llvm::Constant *Mask = llvm::ConstantVector::get(Args);
llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat");
return Yay;
}
case CK_IntegralCast:
case CK_IntegralToFloating:
case CK_FloatingToIntegral:
case CK_FloatingCast:
return EmitScalarConversion(Visit(E), E->getType(), DestTy);
case CK_IntegralToBoolean:
return EmitIntToBoolConversion(Visit(E));
case CK_PointerToBoolean:
return EmitPointerToBoolConversion(Visit(E));
case CK_FloatingToBoolean:
return EmitFloatToBoolConversion(Visit(E));
case CK_MemberPointerToBoolean: {
llvm::Value *MemPtr = Visit(E);
const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>();
return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT);
}
case CK_FloatingComplexToReal:
case CK_IntegralComplexToReal:
return CGF.EmitComplexExpr(E, false, true).first;
case CK_FloatingComplexToBoolean:
case CK_IntegralComplexToBoolean: {
CodeGenFunction::ComplexPairTy V = CGF.EmitComplexExpr(E);
// TODO: kill this function off, inline appropriate case here
return EmitComplexToScalarConversion(V, E->getType(), DestTy);
}
}
llvm_unreachable("unknown scalar cast");
return 0;
}
Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) {
CodeGenFunction::StmtExprEvaluation eval(CGF);
return CGF.EmitCompoundStmt(*E->getSubStmt(), !E->getType()->isVoidType())
.getScalarVal();
}
Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) {
LValue LV = CGF.EmitBlockDeclRefLValue(E);
return CGF.EmitLoadOfLValue(LV).getScalarVal();
}
//===----------------------------------------------------------------------===//
// Unary Operators
//===----------------------------------------------------------------------===//
llvm::Value *ScalarExprEmitter::
EmitAddConsiderOverflowBehavior(const UnaryOperator *E,
llvm::Value *InVal,
llvm::Value *NextVal, bool IsInc) {
switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) {
case LangOptions::SOB_Undefined:
return Builder.CreateNSWAdd(InVal, NextVal, IsInc ? "inc" : "dec");
break;
case LangOptions::SOB_Defined:
return Builder.CreateAdd(InVal, NextVal, IsInc ? "inc" : "dec");
break;
case LangOptions::SOB_Trapping:
BinOpInfo BinOp;
BinOp.LHS = InVal;
BinOp.RHS = NextVal;
BinOp.Ty = E->getType();
BinOp.Opcode = BO_Add;
BinOp.E = E;
return EmitOverflowCheckedBinOp(BinOp);
}
llvm_unreachable("Unknown SignedOverflowBehaviorTy");
}
llvm::Value *
ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
bool isInc, bool isPre) {
QualType type = E->getSubExpr()->getType();
llvm::Value *value = EmitLoadOfLValue(LV);
llvm::Value *input = value;
int amount = (isInc ? 1 : -1);
// Special case of integer increment that we have to check first: bool++.
// 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.
if (isInc && type->isBooleanType()) {
value = Builder.getTrue();
// Most common case by far: integer increment.
} else if (type->isIntegerType()) {
llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount);
// Note that signed integer inc/dec with width less than int can't
// overflow because of promotion rules; we're just eliding a few steps here.
if (type->isSignedIntegerOrEnumerationType() &&
value->getType()->getPrimitiveSizeInBits() >=
CGF.IntTy->getBitWidth())
value = EmitAddConsiderOverflowBehavior(E, value, amt, isInc);
else
value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec");
// Next most common: pointer increment.
} else if (const PointerType *ptr = type->getAs<PointerType>()) {
QualType type = ptr->getPointeeType();
// VLA types don't have constant size.
if (const VariableArrayType *vla
= CGF.getContext().getAsVariableArrayType(type)) {
llvm::Value *numElts = CGF.getVLASize(vla).first;
if (!isInc) numElts = Builder.CreateNSWNeg(numElts, "vla.negsize");
if (CGF.getContext().getLangOptions().isSignedOverflowDefined())
value = Builder.CreateGEP(value, numElts, "vla.inc");
else
value = Builder.CreateInBoundsGEP(value, numElts, "vla.inc");
// Arithmetic on function pointers (!) is just +-1.
} else if (type->isFunctionType()) {
llvm::Value *amt = Builder.getInt32(amount);
value = CGF.EmitCastToVoidPtr(value);
if (CGF.getContext().getLangOptions().isSignedOverflowDefined())
value = Builder.CreateGEP(value, amt, "incdec.funcptr");
else
value = Builder.CreateInBoundsGEP(value, amt, "incdec.funcptr");
value = Builder.CreateBitCast(value, input->getType());
// For everything else, we can just do a simple increment.
} else {
llvm::Value *amt = Builder.getInt32(amount);
if (CGF.getContext().getLangOptions().isSignedOverflowDefined())
value = Builder.CreateGEP(value, amt, "incdec.ptr");
else
value = Builder.CreateInBoundsGEP(value, amt, "incdec.ptr");
}
// Vector increment/decrement.
} else if (type->isVectorType()) {
if (type->hasIntegerRepresentation()) {
llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount);
value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec");
} else {
value = Builder.CreateFAdd(
value,
llvm::ConstantFP::get(value->getType(), amount),
isInc ? "inc" : "dec");
}
// Floating point.
} else if (type->isRealFloatingType()) {
// Add the inc/dec to the real part.
llvm::Value *amt;
if (type->isHalfType()) {
// Another special case: half FP increment should be done via float
value =
Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16),
input);
}
if (value->getType()->isFloatTy())
amt = llvm::ConstantFP::get(VMContext,
llvm::APFloat(static_cast<float>(amount)));
else if (value->getType()->isDoubleTy())
amt = llvm::ConstantFP::get(VMContext,
llvm::APFloat(static_cast<double>(amount)));
else {
llvm::APFloat F(static_cast<float>(amount));
bool ignored;
F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero,
&ignored);
amt = llvm::ConstantFP::get(VMContext, F);
}
value = Builder.CreateFAdd(value, amt, isInc ? "inc" : "dec");
if (type->isHalfType())
value =
Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16),
value);
// Objective-C pointer types.
} else {
const ObjCObjectPointerType *OPT = type->castAs<ObjCObjectPointerType>();
value = CGF.EmitCastToVoidPtr(value);
CharUnits size = CGF.getContext().getTypeSizeInChars(OPT->getObjectType());
if (!isInc) size = -size;
llvm::Value *sizeValue =
llvm::ConstantInt::get(CGF.SizeTy, size.getQuantity());
if (CGF.getContext().getLangOptions().isSignedOverflowDefined())
value = Builder.CreateGEP(value, sizeValue, "incdec.objptr");
else
value = Builder.CreateInBoundsGEP(value, sizeValue, "incdec.objptr");
value = Builder.CreateBitCast(value, input->getType());
}
// Store the updated result through the lvalue.
if (LV.isBitField())
CGF.EmitStoreThroughBitfieldLValue(RValue::get(value), LV, &value);
else
CGF.EmitStoreThroughLValue(RValue::get(value), LV);
// If this is a postinc, return the value read from memory, otherwise use the
// updated value.
return isPre ? value : input;
}
Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
TestAndClearIgnoreResultAssign();
// Emit unary minus with EmitSub so we handle overflow cases etc.
BinOpInfo BinOp;
BinOp.RHS = Visit(E->getSubExpr());
if (BinOp.RHS->getType()->isFPOrFPVectorTy())
BinOp.LHS = llvm::ConstantFP::getZeroValueForNegation(BinOp.RHS->getType());
else
BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType());
BinOp.Ty = E->getType();
BinOp.Opcode = BO_Sub;
BinOp.E = E;
return EmitSub(BinOp);
}
Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
TestAndClearIgnoreResultAssign();
Value *Op = Visit(E->getSubExpr());
return Builder.CreateNot(Op, "neg");
}
Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) {
// Compare operand to zero.
Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr());
// Invert value.
// TODO: Could dynamically modify easy computations here. For example, if
// the operand is an icmp ne, turn into icmp eq.
BoolVal = Builder.CreateNot(BoolVal, "lnot");
// ZExt result to the expr type.
return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext");
}
Value *ScalarExprEmitter::VisitOffsetOfExpr(OffsetOfExpr *E) {
// Try folding the offsetof to a constant.
Expr::EvalResult EvalResult;
if (E->EvaluateAsRValue(EvalResult, CGF.getContext()))
return Builder.getInt(EvalResult.Val.getInt());
// Loop over the components of the offsetof to compute the value.
unsigned n = E->getNumComponents();
llvm::Type* ResultType = ConvertType(E->getType());
llvm::Value* Result = llvm::Constant::getNullValue(ResultType);
QualType CurrentType = E->getTypeSourceInfo()->getType();
for (unsigned i = 0; i != n; ++i) {
OffsetOfExpr::OffsetOfNode ON = E->getComponent(i);
llvm::Value *Offset = 0;
switch (ON.getKind()) {
case OffsetOfExpr::OffsetOfNode::Array: {
// Compute the index
Expr *IdxExpr = E->getIndexExpr(ON.getArrayExprIndex());
llvm::Value* Idx = CGF.EmitScalarExpr(IdxExpr);
bool IdxSigned = IdxExpr->getType()->isSignedIntegerOrEnumerationType();
Idx = Builder.CreateIntCast(Idx, ResultType, IdxSigned, "conv");
// Save the element type
CurrentType =
CGF.getContext().getAsArrayType(CurrentType)->getElementType();
// Compute the element size
llvm::Value* ElemSize = llvm::ConstantInt::get(ResultType,
CGF.getContext().getTypeSizeInChars(CurrentType).getQuantity());
// Multiply out to compute the result
Offset = Builder.CreateMul(Idx, ElemSize);
break;
}
case OffsetOfExpr::OffsetOfNode::Field: {
FieldDecl *MemberDecl = ON.getField();
RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl();
const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD);
// Compute the index of the field in its parent.
unsigned i = 0;
// FIXME: It would be nice if we didn't have to loop here!
for (RecordDecl::field_iterator Field = RD->field_begin(),
FieldEnd = RD->field_end();
Field != FieldEnd; (void)++Field, ++i) {
if (*Field == MemberDecl)
break;
}
assert(i < RL.getFieldCount() && "offsetof field in wrong type");
// Compute the offset to the field
int64_t OffsetInt = RL.getFieldOffset(i) /
CGF.getContext().getCharWidth();
Offset = llvm::ConstantInt::get(ResultType, OffsetInt);
// Save the element type.
CurrentType = MemberDecl->getType();
break;
}
case OffsetOfExpr::OffsetOfNode::Identifier:
llvm_unreachable("dependent __builtin_offsetof");
case OffsetOfExpr::OffsetOfNode::Base: {
if (ON.getBase()->isVirtual()) {
CGF.ErrorUnsupported(E, "virtual base in offsetof");
continue;
}
RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl();
const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD);
// Save the element type.
CurrentType = ON.getBase()->getType();
// Compute the offset to the base.
const RecordType *BaseRT = CurrentType->getAs<RecordType>();
CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl());
int64_t OffsetInt = RL.getBaseClassOffsetInBits(BaseRD) /
CGF.getContext().getCharWidth();
Offset = llvm::ConstantInt::get(ResultType, OffsetInt);
break;
}
}
Result = Builder.CreateAdd(Result, Offset);
}
return Result;
}
/// VisitUnaryExprOrTypeTraitExpr - Return the size or alignment of the type of
/// argument of the sizeof expression as an integer.
Value *
ScalarExprEmitter::VisitUnaryExprOrTypeTraitExpr(
const UnaryExprOrTypeTraitExpr *E) {
QualType TypeToSize = E->getTypeOfArgument();
if (E->getKind() == UETT_SizeOf) {
if (const VariableArrayType *VAT =
CGF.getContext().getAsVariableArrayType(TypeToSize)) {
if (E->isArgumentType()) {
// sizeof(type) - make sure to emit the VLA size.
CGF.EmitVariablyModifiedType(TypeToSize);
} else {
// C99 6.5.3.4p2: If the argument is an expression of type
// VLA, it is evaluated.
CGF.EmitIgnoredExpr(E->getArgumentExpr());
}
QualType eltType;
llvm::Value *numElts;
llvm::tie(numElts, eltType) = CGF.getVLASize(VAT);
llvm::Value *size = numElts;
// Scale the number of non-VLA elements by the non-VLA element size.
CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
if (!eltSize.isOne())
size = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), numElts);
return size;
}
}
// 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->EvaluateAsRValue(Result, CGF.getContext());
return Builder.getInt(Result.Val.getInt());
}
Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) {
Expr *Op = E->getSubExpr();
if (Op->getType()->isAnyComplexType()) {
// If it's an l-value, load through the appropriate subobject l-value.
// Note that we have to ask E because Op might be an l-value that
// this won't work for, e.g. an Obj-C property.
if (E->isGLValue())
return CGF.EmitLoadOfLValue(CGF.EmitLValue(E)).getScalarVal();
// Otherwise, calculate and project.
return CGF.EmitComplexExpr(Op, false, true).first;
}
return Visit(Op);
}
Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) {
Expr *Op = E->getSubExpr();
if (Op->getType()->isAnyComplexType()) {
// If it's an l-value, load through the appropriate subobject l-value.
// Note that we have to ask E because Op might be an l-value that
// this won't work for, e.g. an Obj-C property.
if (Op->isGLValue())
return CGF.EmitLoadOfLValue(CGF.EmitLValue(E)).getScalarVal();
// Otherwise, calculate and project.
return CGF.EmitComplexExpr(Op, true, false).second;
}
// __imag on a scalar returns zero. Emit the subexpr to ensure side
// effects are evaluated, but not the actual value.
CGF.EmitScalarExpr(Op, true);
return llvm::Constant::getNullValue(ConvertType(E->getType()));
}
//===----------------------------------------------------------------------===//
// 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.Opcode = E->getOpcode();
Result.E = E;
return Result;
}
LValue ScalarExprEmitter::EmitCompoundAssignLValue(
const CompoundAssignOperator *E,
Value *(ScalarExprEmitter::*Func)(const BinOpInfo &),
Value *&Result) {
QualType LHSTy = E->getLHS()->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");
Result = llvm::UndefValue::get(CGF.ConvertType(E->getType()));
return LValue();
}
// Emit the RHS first. __block variables need to have the rhs evaluated
// first, plus this should improve codegen a little.
OpInfo.RHS = Visit(E->getRHS());
OpInfo.Ty = E->getComputationResultType();
OpInfo.Opcode = E->getOpcode();
OpInfo.E = E;
// Load/convert the LHS.
LValue LHSLV = EmitCheckedLValue(E->getLHS());
OpInfo.LHS = EmitLoadOfLValue(LHSLV);
OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy,
E->getComputationLHSType());
// Expand the binary operator.
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())
CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, &Result);
else
CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV);
return LHSLV;
}
Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E,
Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) {
bool Ignore = TestAndClearIgnoreResultAssign();
Value *RHS;
LValue LHS = EmitCompoundAssignLValue(E, Func, RHS);
// If the result is clearly ignored, return now.
if (Ignore)
return 0;
// The result of an assignment in C is the assigned r-value.
if (!CGF.getContext().getLangOptions().CPlusPlus)
return RHS;
// If the lvalue is non-volatile, return the computed value of the assignment.
if (!LHS.isVolatileQualified())
return RHS;
// Otherwise, reload the value.
return EmitLoadOfLValue(LHS);
}
void ScalarExprEmitter::EmitUndefinedBehaviorIntegerDivAndRemCheck(
const BinOpInfo &Ops,
llvm::Value *Zero, bool isDiv) {
llvm::Function::iterator insertPt = Builder.GetInsertBlock();
llvm::BasicBlock *contBB =
CGF.createBasicBlock(isDiv ? "div.cont" : "rem.cont", CGF.CurFn,
llvm::next(insertPt));
llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn);
llvm::IntegerType *Ty = cast<llvm::IntegerType>(Zero->getType());
if (Ops.Ty->hasSignedIntegerRepresentation()) {
llvm::Value *IntMin =
Builder.getInt(llvm::APInt::getSignedMinValue(Ty->getBitWidth()));
llvm::Value *NegOne = llvm::ConstantInt::get(Ty, -1ULL);
llvm::Value *Cond1 = Builder.CreateICmpEQ(Ops.RHS, Zero);
llvm::Value *LHSCmp = Builder.CreateICmpEQ(Ops.LHS, IntMin);
llvm::Value *RHSCmp = Builder.CreateICmpEQ(Ops.RHS, NegOne);
llvm::Value *Cond2 = Builder.CreateAnd(LHSCmp, RHSCmp, "and");
Builder.CreateCondBr(Builder.CreateOr(Cond1, Cond2, "or"),
overflowBB, contBB);
} else {
CGF.Builder.CreateCondBr(Builder.CreateICmpEQ(Ops.RHS, Zero),
overflowBB, contBB);
}
EmitOverflowBB(overflowBB);
Builder.SetInsertPoint(contBB);
}
Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) {
if (isTrapvOverflowBehavior()) {
llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty));
if (Ops.Ty->isIntegerType())
EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, true);
else if (Ops.Ty->isRealFloatingType()) {
llvm::Function::iterator insertPt = Builder.GetInsertBlock();
llvm::BasicBlock *DivCont = CGF.createBasicBlock("div.cont", CGF.CurFn,
llvm::next(insertPt));
llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow",
CGF.CurFn);
CGF.Builder.CreateCondBr(Builder.CreateFCmpOEQ(Ops.RHS, Zero),
overflowBB, DivCont);
EmitOverflowBB(overflowBB);
Builder.SetInsertPoint(DivCont);
}
}
if (Ops.LHS->getType()->isFPOrFPVectorTy()) {
llvm::Value *Val = Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div");
if (CGF.getContext().getLangOptions().OpenCL) {
// OpenCL 1.1 7.4: minimum accuracy of single precision / is 2.5ulp
llvm::Type *ValTy = Val->getType();
if (ValTy->isFloatTy() ||
(isa<llvm::VectorType>(ValTy) &&
cast<llvm::VectorType>(ValTy)->getElementType()->isFloatTy()))
CGF.SetFPAccuracy(Val, 5, 2);
}
return Val;
}
else if (Ops.Ty->hasUnsignedIntegerRepresentation())
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 (isTrapvOverflowBehavior()) {
llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty));
if (Ops.Ty->isIntegerType())
EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, false);
}
if (Ops.Ty->hasUnsignedIntegerRepresentation())
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.Opcode) {
case BO_Add:
case BO_AddAssign:
OpID = 1;
IID = llvm::Intrinsic::sadd_with_overflow;
break;
case BO_Sub:
case BO_SubAssign:
OpID = 2;
IID = llvm::Intrinsic::ssub_with_overflow;
break;
case BO_Mul:
case BO_MulAssign:
OpID = 3;
IID = llvm::Intrinsic::smul_with_overflow;
break;
default:
llvm_unreachable("Unsupported operation for overflow detection");
IID = 0;
}
OpID <<= 1;
OpID |= 1;
llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty);
llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, opTy);
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::Function::iterator insertPt = initialBB;
llvm::BasicBlock *continueBB = CGF.createBasicBlock("nooverflow", CGF.CurFn,
llvm::next(insertPt));
llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn);
Builder.CreateCondBr(overflow, overflowBB, continueBB);
// Handle overflow with llvm.trap.
const std::string *handlerName =
&CGF.getContext().getLangOptions().OverflowHandler;
if (handlerName->empty()) {
EmitOverflowBB(overflowBB);
Builder.SetInsertPoint(continueBB);
return result;
}
// If an overflow handler is set, then we want to call it and then use its
// result, if it returns.
Builder.SetInsertPoint(overflowBB);
// Get the overflow handler.
llvm::Type *Int8Ty = llvm::Type::getInt8Ty(VMContext);
llvm::Type *argTypes[] = { CGF.Int64Ty, CGF.Int64Ty, Int8Ty, Int8Ty };
llvm::FunctionType *handlerTy =
llvm::FunctionType::get(CGF.Int64Ty, argTypes, true);
llvm::Value *handler = CGF.CGM.CreateRuntimeFunction(handlerTy, *handlerName);
// Sign extend the args to 64-bit, so that we can use the same handler for
// all types of overflow.
llvm::Value *lhs = Builder.CreateSExt(Ops.LHS, CGF.Int64Ty);
llvm::Value *rhs = Builder.CreateSExt(Ops.RHS, CGF.Int64Ty);
// Call the handler with the two arguments, the operation, and the size of
// the result.
llvm::Value *handlerResult = Builder.CreateCall4(handler, lhs, rhs,
Builder.getInt8(OpID),
Builder.getInt8(cast<llvm::IntegerType>(opTy)->getBitWidth()));
// Truncate the result back to the desired size.
handlerResult = Builder.CreateTrunc(handlerResult, opTy);
Builder.CreateBr(continueBB);
Builder.SetInsertPoint(continueBB);
llvm::PHINode *phi = Builder.CreatePHI(opTy, 2);
phi->addIncoming(result, initialBB);
phi->addIncoming(handlerResult, overflowBB);
return phi;
}
/// Emit pointer + index arithmetic.
static Value *emitPointerArithmetic(CodeGenFunction &CGF,
const BinOpInfo &op,
bool isSubtraction) {
// Must have binary (not unary) expr here. Unary pointer
// increment/decrement doesn't use this path.
const BinaryOperator *expr = cast<BinaryOperator>(op.E);
Value *pointer = op.LHS;
Expr *pointerOperand = expr->getLHS();
Value *index = op.RHS;
Expr *indexOperand = expr->getRHS();
// In a subtraction, the LHS is always the pointer.
if (!isSubtraction && !pointer->getType()->isPointerTy()) {
std::swap(pointer, index);
std::swap(pointerOperand, indexOperand);
}
unsigned width = cast<llvm::IntegerType>(index->getType())->getBitWidth();
if (width != CGF.PointerWidthInBits) {
// Zero-extend or sign-extend the pointer value according to
// whether the index is signed or not.
bool isSigned = indexOperand->getType()->isSignedIntegerOrEnumerationType();
index = CGF.Builder.CreateIntCast(index, CGF.PtrDiffTy, isSigned,
"idx.ext");
}
// If this is subtraction, negate the index.
if (isSubtraction)
index = CGF.Builder.CreateNeg(index, "idx.neg");
const PointerType *pointerType
= pointerOperand->getType()->getAs<PointerType>();
if (!pointerType) {
QualType objectType = pointerOperand->getType()
->castAs<ObjCObjectPointerType>()
->getPointeeType();
llvm::Value *objectSize
= CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(objectType));
index = CGF.Builder.CreateMul(index, objectSize);
Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy);
result = CGF.Builder.CreateGEP(result, index, "add.ptr");
return CGF.Builder.CreateBitCast(result, pointer->getType());
}
QualType elementType = pointerType->getPointeeType();
if (const VariableArrayType *vla
= CGF.getContext().getAsVariableArrayType(elementType)) {
// The element count here is the total number of non-VLA elements.
llvm::Value *numElements = CGF.getVLASize(vla).first;
// Effectively, the multiply by the VLA size is part of the GEP.
// GEP indexes are signed, and scaling an index isn't permitted to
// signed-overflow, so we use the same semantics for our explicit
// multiply. We suppress this if overflow is not undefined behavior.
if (CGF.getLangOptions().isSignedOverflowDefined()) {
index = CGF.Builder.CreateMul(index, numElements, "vla.index");
pointer = CGF.Builder.CreateGEP(pointer, index, "add.ptr");
} else {
index = CGF.Builder.CreateNSWMul(index, numElements, "vla.index");
pointer = CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr");
}
return pointer;
}
// 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()) {
Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy);
result = CGF.Builder.CreateGEP(result, index, "add.ptr");
return CGF.Builder.CreateBitCast(result, pointer->getType());
}
if (CGF.getLangOptions().isSignedOverflowDefined())
return CGF.Builder.CreateGEP(pointer, index, "add.ptr");
return CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr");
}
Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &op) {
if (op.LHS->getType()->isPointerTy() ||
op.RHS->getType()->isPointerTy())
return emitPointerArithmetic(CGF, op, /*subtraction*/ false);
if (op.Ty->isSignedIntegerOrEnumerationType()) {
switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) {
case LangOptions::SOB_Undefined:
return Builder.CreateNSWAdd(op.LHS, op.RHS, "add");
case LangOptions::SOB_Defined:
return Builder.CreateAdd(op.LHS, op.RHS, "add");
case LangOptions::SOB_Trapping:
return EmitOverflowCheckedBinOp(op);
}
}
if (op.LHS->getType()->isFPOrFPVectorTy())
return Builder.CreateFAdd(op.LHS, op.RHS, "add");
return Builder.CreateAdd(op.LHS, op.RHS, "add");
}
Value *ScalarExprEmitter::EmitSub(const BinOpInfo &op) {
// The LHS is always a pointer if either side is.
if (!op.LHS->getType()->isPointerTy()) {
if (op.Ty->isSignedIntegerOrEnumerationType()) {
switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) {
case LangOptions::SOB_Undefined:
return Builder.CreateNSWSub(op.LHS, op.RHS, "sub");
case LangOptions::SOB_Defined:
return Builder.CreateSub(op.LHS, op.RHS, "sub");
case LangOptions::SOB_Trapping:
return EmitOverflowCheckedBinOp(op);
}
}
if (op.LHS->getType()->isFPOrFPVectorTy())
return Builder.CreateFSub(op.LHS, op.RHS, "sub");
return Builder.CreateSub(op.LHS, op.RHS, "sub");
}
// If the RHS is not a pointer, then we have normal pointer
// arithmetic.
if (!op.RHS->getType()->isPointerTy())
return emitPointerArithmetic(CGF, op, /*subtraction*/ true);
// Otherwise, this is a pointer subtraction.
// Do the raw subtraction part.
llvm::Value *LHS
= Builder.CreatePtrToInt(op.LHS, CGF.PtrDiffTy, "sub.ptr.lhs.cast");
llvm::Value *RHS
= Builder.CreatePtrToInt(op.RHS, CGF.PtrDiffTy, "sub.ptr.rhs.cast");
Value *diffInChars = Builder.CreateSub(LHS, RHS, "sub.ptr.sub");
// Okay, figure out the element size.
const BinaryOperator *expr = cast<BinaryOperator>(op.E);
QualType elementType = expr->getLHS()->getType()->getPointeeType();
llvm::Value *divisor = 0;
// For a variable-length array, this is going to be non-constant.
if (const VariableArrayType *vla
= CGF.getContext().getAsVariableArrayType(elementType)) {
llvm::Value *numElements;
llvm::tie(numElements, elementType) = CGF.getVLASize(vla);
divisor = numElements;
// Scale the number of non-VLA elements by the non-VLA element size.
CharUnits eltSize = CGF.getContext().getTypeSizeInChars(elementType);
if (!eltSize.isOne())
divisor = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), divisor);
// For everything elese, we can just compute it, safe in the
// assumption that Sema won't let anything through that we can't
// safely compute the size of.
} else {
CharUnits elementSize;
// Handle GCC extension for pointer arithmetic on void* and
// function pointer types.
if (elementType->isVoidType() || elementType->isFunctionType())
elementSize = CharUnits::One();
else
elementSize = CGF.getContext().getTypeSizeInChars(elementType);
// Don't even emit the divide for element size of 1.
if (elementSize.isOne())
return diffInChars;
divisor = CGF.CGM.getSize(elementSize);
}
// 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.
return Builder.CreateExactSDiv(diffInChars, divisor, "sub.ptr.div");
}
Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) {
// LLVM requires the LHS and RHS to be the same type: promote or truncate the
// RHS to the same size as the LHS.
Value *RHS = Ops.RHS;
if (Ops.LHS->getType() != RHS->getType())
RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom");
if (CGF.CatchUndefined
&& isa<llvm::IntegerType>(Ops.LHS->getType())) {
unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth();
llvm::BasicBlock *Cont = CGF.createBasicBlock("cont");
CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS,
llvm::ConstantInt::get(RHS->getType(), Width)),
Cont, CGF.getTrapBB());
CGF.EmitBlock(Cont);
}
return Builder.CreateShl(Ops.LHS, RHS, "shl");
}
Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) {
// LLVM requires the LHS and RHS to be the same type: promote or truncate the
// RHS to the same size as the LHS.
Value *RHS = Ops.RHS;
if (Ops.LHS->getType() != RHS->getType())
RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom");
if (CGF.CatchUndefined
&& isa<llvm::IntegerType>(Ops.LHS->getType())) {
unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth();
llvm::BasicBlock *Cont = CGF.createBasicBlock("cont");
CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS,
llvm::ConstantInt::get(RHS->getType(), Width)),
Cont, CGF.getTrapBB());
CGF.EmitBlock(Cont);
}
if (Ops.Ty->hasUnsignedIntegerRepresentation())
return Builder.CreateLShr(Ops.LHS, RHS, "shr");
return Builder.CreateAShr(Ops.LHS, RHS, "shr");
}
enum IntrinsicType { VCMPEQ, VCMPGT };
// return corresponding comparison intrinsic for given vector type
static llvm::Intrinsic::ID GetIntrinsic(IntrinsicType IT,
BuiltinType::Kind ElemKind) {
switch (ElemKind) {
default: llvm_unreachable("unexpected element type");
case BuiltinType::Char_U:
case BuiltinType::UChar:
return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p :
llvm::Intrinsic::ppc_altivec_vcmpgtub_p;
break;
case BuiltinType::Char_S:
case BuiltinType::SChar:
return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p :
llvm::Intrinsic::ppc_altivec_vcmpgtsb_p;
break;
case BuiltinType::UShort:
return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p :
llvm::Intrinsic::ppc_altivec_vcmpgtuh_p;
break;
case BuiltinType::Short:
return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p :
llvm::Intrinsic::ppc_altivec_vcmpgtsh_p;
break;
case BuiltinType::UInt:
case BuiltinType::ULong:
return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p :
llvm::Intrinsic::ppc_altivec_vcmpgtuw_p;
break;
case BuiltinType::Int:
case BuiltinType::Long:
return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p :
llvm::Intrinsic::ppc_altivec_vcmpgtsw_p;
break;
case BuiltinType::Float:
return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpeqfp_p :
llvm::Intrinsic::ppc_altivec_vcmpgtfp_p;
break;
}
return llvm::Intrinsic::not_intrinsic;
}
Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc,
unsigned SICmpOpc, unsigned FCmpOpc) {
TestAndClearIgnoreResultAssign();
Value *Result;
QualType LHSTy = E->getLHS()->getType();
if (const MemberPointerType *MPT = LHSTy->getAs<MemberPointerType>()) {
assert(E->getOpcode() == BO_EQ ||
E->getOpcode() == BO_NE);
Value *LHS = CGF.EmitScalarExpr(E->getLHS());
Value *RHS = CGF.EmitScalarExpr(E->getRHS());
Result = CGF.CGM.getCXXABI().EmitMemberPointerComparison(
CGF, LHS, RHS, MPT, E->getOpcode() == BO_NE);
} else if (!LHSTy->isAnyComplexType()) {
Value *LHS = Visit(E->getLHS());
Value *RHS = Visit(E->getRHS());
// If AltiVec, the comparison results in a numeric type, so we use
// intrinsics comparing vectors and giving 0 or 1 as a result
if (LHSTy->isVectorType() && !E->getType()->isVectorType()) {
// constants for mapping CR6 register bits to predicate result
enum { CR6_EQ=0, CR6_EQ_REV, CR6_LT, CR6_LT_REV } CR6;
llvm::Intrinsic::ID ID = llvm::Intrinsic::not_intrinsic;
// in several cases vector arguments order will be reversed
Value *FirstVecArg = LHS,
*SecondVecArg = RHS;
QualType ElTy = LHSTy->getAs<VectorType>()->getElementType();
const BuiltinType *BTy = ElTy->getAs<BuiltinType>();
BuiltinType::Kind ElementKind = BTy->getKind();
switch(E->getOpcode()) {
default: llvm_unreachable("is not a comparison operation");
case BO_EQ:
CR6 = CR6_LT;
ID = GetIntrinsic(VCMPEQ, ElementKind);
break;
case BO_NE:
CR6 = CR6_EQ;
ID = GetIntrinsic(VCMPEQ, ElementKind);
break;
case BO_LT:
CR6 = CR6_LT;
ID = GetIntrinsic(VCMPGT, ElementKind);
std::swap(FirstVecArg, SecondVecArg);
break;
case BO_GT:
CR6 = CR6_LT;
ID = GetIntrinsic(VCMPGT, ElementKind);
break;
case BO_LE:
if (ElementKind == BuiltinType::Float) {
CR6 = CR6_LT;
ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p;
std::swap(FirstVecArg, SecondVecArg);
}
else {
CR6 = CR6_EQ;
ID = GetIntrinsic(VCMPGT, ElementKind);
}
break;
case BO_GE:
if (ElementKind == BuiltinType::Float) {
CR6 = CR6_LT;
ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p;
}
else {
CR6 = CR6_EQ;
ID = GetIntrinsic(VCMPGT, ElementKind);
std::swap(FirstVecArg, SecondVecArg);
}
break;
}
Value *CR6Param = Builder.getInt32(CR6);
llvm::Function *F = CGF.CGM.getIntrinsic(ID);
Result = Builder.CreateCall3(F, CR6Param, FirstVecArg, SecondVecArg, "");
return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType());
}
if (LHS->getType()->isFPOrFPVectorTy()) {
Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc,
LHS, RHS, "cmp");
} else if (LHSTy->hasSignedIntegerRepresentation()) {
Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc,
LHS, RHS, "cmp");
} else {
// Unsigned integers and pointers.
Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
LHS, RHS, "cmp");
}
// If this is a vector comparison, sign extend the result to the appropriate
// vector integer type and return it (don't convert to bool).
if (LHSTy->isVectorType())
return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext");
} else {
// Complex Comparison: can only be an equality comparison.
CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS());
CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS());
QualType CETy = LHSTy->getAs<ComplexType>()->getElementType();
Value *ResultR, *ResultI;
if (CETy->isRealFloatingType()) {
ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc,
LHS.first, RHS.first, "cmp.r");
ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc,
LHS.second, RHS.second, "cmp.i");
} else {
// Complex comparisons can only be equality comparisons. As such, signed
// and unsigned opcodes are the same.
ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
LHS.first, RHS.first, "cmp.r");
ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
LHS.second, RHS.second, "cmp.i");
}
if (E->getOpcode() == BO_EQ) {
Result = Builder.CreateAnd(ResultR, ResultI, "and.ri");
} else {
assert(E->getOpcode() == BO_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();
Value *RHS;
LValue LHS;
switch (E->getLHS()->getType().getObjCLifetime()) {
case Qualifiers::OCL_Strong:
llvm::tie(LHS, RHS) = CGF.EmitARCStoreStrong(E, Ignore);
break;
case Qualifiers::OCL_Autoreleasing:
llvm::tie(LHS,RHS) = CGF.EmitARCStoreAutoreleasing(E);
break;
case Qualifiers::OCL_Weak:
RHS = Visit(E->getRHS());
LHS = EmitCheckedLValue(E->getLHS());
RHS = CGF.EmitARCStoreWeak(LHS.getAddress(), RHS, Ignore);
break;
// No reason to do any of these differently.
case Qualifiers::OCL_None:
case Qualifiers::OCL_ExplicitNone:
// __block variables need to have the rhs evaluated first, plus
// this should improve codegen just a little.
RHS = Visit(E->getRHS());
LHS = EmitCheckedLValue(E->getLHS());
// Store the value into the LHS. Bit-fields are handled specially
// because the result is altered by the store, i.e., [C99 6.5.16p1]
// 'An assignment expression has the value of the left operand after
// the assignment...'.
if (LHS.isBitField())
CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, &RHS);
else
CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS);
}
// If the result is clearly ignored, return now.
if (Ignore)
return 0;
// The result of an assignment in C is the assigned r-value.
if (!CGF.getContext().getLangOptions().CPlusPlus)
return RHS;
// If the lvalue is non-volatile, return the computed value of the assignment.
if (!LHS.isVolatileQualified())
return RHS;
// Otherwise, reload the value.
return EmitLoadOfLValue(LHS);
}
Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) {
llvm::Type *ResTy = ConvertType(E->getType());
// If we have 0 && RHS, see if we can elide RHS, if so, just return 0.
// If we have 1 && X, just emit X without inserting the control flow.
bool LHSCondVal;
if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) {
if (LHSCondVal) { // If we have 1 && X, just emit X.
Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
// ZExt result to int or bool.
return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext");
}
// 0 && RHS: If it is safe, just elide the RHS, and return 0/false.
if (!CGF.ContainsLabel(E->getRHS()))
return llvm::Constant::getNullValue(ResTy);
}
llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end");
llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs");
CodeGenFunction::ConditionalEvaluation eval(CGF);
// 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), 2,
"", ContBlock);
for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock);
PI != PE; ++PI)
PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI);
eval.begin(CGF);
CGF.EmitBlock(RHSBlock);
Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
eval.end(CGF);
// 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.
if (CGF.getDebugInfo())
// There is no need to emit line number for unconditional branch.
Builder.SetCurrentDebugLocation(llvm::DebugLoc());
CGF.EmitBlock(ContBlock);
PN->addIncoming(RHSCond, RHSBlock);
// ZExt result to int.
return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext");
}
Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) {
llvm::Type *ResTy = ConvertType(E->getType());
// If we have 1 || RHS, see if we can elide RHS, if so, just return 1.
// If we have 0 || X, just emit X without inserting the control flow.
bool LHSCondVal;
if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) {
if (!LHSCondVal) { // If we have 0 || X, just emit X.
Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
// ZExt result to int or bool.
return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext");
}
// 1 || RHS: If it is safe, just elide the RHS, and return 1/true.
if (!CGF.ContainsLabel(E->getRHS()))
return llvm::ConstantInt::get(ResTy, 1);
}
llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end");
llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs");
CodeGenFunction::ConditionalEvaluation eval(CGF);
// 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), 2,
"", ContBlock);
for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock);
PI != PE; ++PI)
PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI);
eval.begin(CGF);
// Emit the RHS condition as a bool value.
CGF.EmitBlock(RHSBlock);
Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
eval.end(CGF);
// Reaquire the RHS block, as there may be subblocks inserted.
RHSBlock = Builder.GetInsertBlock();
// Emit an unconditional branch from this block to ContBlock. Insert an entry
// into the phi node for the edge with the value of RHSCond.
CGF.EmitBlock(ContBlock);
PN->addIncoming(RHSCond, RHSBlock);
// ZExt result to int.
return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext");
}
Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) {
CGF.EmitIgnoredExpr(E->getLHS());
CGF.EnsureInsertPoint();
return Visit(E->getRHS());
}
//===----------------------------------------------------------------------===//
// Other Operators
//===----------------------------------------------------------------------===//
/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified
/// expression is cheap enough and side-effect-free enough to evaluate
/// unconditionally instead of conditionally. This is used to convert control
/// flow into selects in some cases.
static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E,
CodeGenFunction &CGF) {
E = E->IgnoreParens();
// Anything that is an integer or floating point constant is fine.
if (E->isConstantInitializer(CGF.getContext(), false))
return true;
// Non-volatile automatic variables too, to get "cond ? X : Y" where
// X and Y are local variables.
if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl()))
if (VD->hasLocalStorage() && !(CGF.getContext()
.getCanonicalType(VD->getType())
.isVolatileQualified()))
return true;
return false;
}
Value *ScalarExprEmitter::
VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
TestAndClearIgnoreResultAssign();
// Bind the common expression if necessary.
CodeGenFunction::OpaqueValueMapping binding(CGF, E);
Expr *condExpr = E->getCond();
Expr *lhsExpr = E->getTrueExpr();
Expr *rhsExpr = E->getFalseExpr();
// If the condition constant folds and can be elided, try to avoid emitting
// the condition and the dead arm.
bool CondExprBool;
if (CGF.ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
Expr *live = lhsExpr, *dead = rhsExpr;
if (!CondExprBool) std::swap(live, dead);
// If the dead side doesn't have labels we need, just emit the Live part.
if (!CGF.ContainsLabel(dead)) {
Value *Result = Visit(live);
// If the live part is a throw expression, it acts like it has a void
// type, so evaluating it returns a null Value*. However, a conditional
// with non-void type must return a non-null Value*.
if (!Result && !E->getType()->isVoidType())
Result = llvm::UndefValue::get(CGF.ConvertType(E->getType()));
return Result;
}
}
// OpenCL: If the condition is a vector, we can treat this condition like
// the select function.
if (CGF.getContext().getLangOptions().OpenCL
&& condExpr->getType()->isVectorType()) {
llvm::Value *CondV = CGF.EmitScalarExpr(condExpr);
llvm::Value *LHS = Visit(lhsExpr);
llvm::Value *RHS = Visit(rhsExpr);
llvm::Type *condType = ConvertType(condExpr->getType());
llvm::VectorType *vecTy = cast<llvm::VectorType>(condType);
unsigned numElem = vecTy->getNumElements();
llvm::Type *elemType = vecTy->getElementType();
std::vector<llvm::Constant*> Zvals;
for (unsigned i = 0; i < numElem; ++i)
Zvals.push_back(llvm::ConstantInt::get(elemType, 0));
llvm::Value *zeroVec = llvm::ConstantVector::get(Zvals);
llvm::Value *TestMSB = Builder.CreateICmpSLT(CondV, zeroVec);
llvm::Value *tmp = Builder.CreateSExt(TestMSB,
llvm::VectorType::get(elemType,
numElem),
"sext");
llvm::Value *tmp2 = Builder.CreateNot(tmp);
// Cast float to int to perform ANDs if necessary.
llvm::Value *RHSTmp = RHS;
llvm::Value *LHSTmp = LHS;
bool wasCast = false;
llvm::VectorType *rhsVTy = cast<llvm::VectorType>(RHS->getType());
if (rhsVTy->getElementType()->isFloatTy()) {
RHSTmp = Builder.CreateBitCast(RHS, tmp2->getType());
LHSTmp = Builder.CreateBitCast(LHS, tmp->getType());
wasCast = true;
}
llvm::Value *tmp3 = Builder.CreateAnd(RHSTmp, tmp2);
llvm::Value *tmp4 = Builder.CreateAnd(LHSTmp, tmp);
llvm::Value *tmp5 = Builder.CreateOr(tmp3, tmp4, "cond");
if (wasCast)
tmp5 = Builder.CreateBitCast(tmp5, RHS->getType());
return tmp5;
}
// 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 (isCheapEnoughToEvaluateUnconditionally(lhsExpr, CGF) &&
isCheapEnoughToEvaluateUnconditionally(rhsExpr, CGF)) {
llvm::Value *CondV = CGF.EvaluateExprAsBool(condExpr);
llvm::Value *LHS = Visit(lhsExpr);
llvm::Value *RHS = Visit(rhsExpr);
if (!LHS) {
// If the conditional has void type, make sure we return a null Value*.
assert(!RHS && "LHS and RHS types must match");
return 0;
}
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");
CodeGenFunction::ConditionalEvaluation eval(CGF);
CGF.EmitBranchOnBoolExpr(condExpr, LHSBlock, RHSBlock);
CGF.EmitBlock(LHSBlock);
eval.begin(CGF);
Value *LHS = Visit(lhsExpr);
eval.end(CGF);
LHSBlock = Builder.GetInsertBlock();
Builder.CreateBr(ContBlock);
CGF.EmitBlock(RHSBlock);
eval.begin(CGF);
Value *RHS = Visit(rhsExpr);
eval.end(CGF);
RHSBlock = Builder.GetInsertBlock();
CGF.EmitBlock(ContBlock);
// If the LHS or RHS is a throw expression, it will be legitimately null.
if (!LHS)
return RHS;
if (!RHS)
return LHS;
// Create a PHI node for the real part.
llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), 2, "cond");
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 *block) {
return CGF.EmitBlockLiteral(block);
}
Value *ScalarExprEmitter::VisitAsTypeExpr(AsTypeExpr *E) {
Value *Src = CGF.EmitScalarExpr(E->getSrcExpr());
llvm::Type *DstTy = ConvertType(E->getType());
// Going from vec4->vec3 or vec3->vec4 is a special case and requires
// a shuffle vector instead of a bitcast.
llvm::Type *SrcTy = Src->getType();
if (isa<llvm::VectorType>(DstTy) && isa<llvm::VectorType>(SrcTy)) {
unsigned numElementsDst = cast<llvm::VectorType>(DstTy)->getNumElements();
unsigned numElementsSrc = cast<llvm::VectorType>(SrcTy)->getNumElements();
if ((numElementsDst == 3 && numElementsSrc == 4)
|| (numElementsDst == 4 && numElementsSrc == 3)) {
// In the case of going from int4->float3, a bitcast is needed before
// doing a shuffle.
llvm::Type *srcElemTy =
cast<llvm::VectorType>(SrcTy)->getElementType();
llvm::Type *dstElemTy =
cast<llvm::VectorType>(DstTy)->getElementType();
if ((srcElemTy->isIntegerTy() && dstElemTy->isFloatTy())
|| (srcElemTy->isFloatTy() && dstElemTy->isIntegerTy())) {
// Create a float type of the same size as the source or destination.
llvm::VectorType *newSrcTy = llvm::VectorType::get(dstElemTy,
numElementsSrc);
Src = Builder.CreateBitCast(Src, newSrcTy, "astypeCast");
}
llvm::Value *UnV = llvm::UndefValue::get(Src->getType());
SmallVector<llvm::Constant*, 3> Args;
Args.push_back(Builder.getInt32(0));
Args.push_back(Builder.getInt32(1));
Args.push_back(Builder.getInt32(2));
if (numElementsDst == 4)
Args.push_back(llvm::UndefValue::get(
llvm::Type::getInt32Ty(CGF.getLLVMContext())));
llvm::Constant *Mask = llvm::ConstantVector::get(Args);
return Builder.CreateShuffleVector(Src, UnV, Mask, "astype");
}
}
return Builder.CreateBitCast(Src, DstTy, "astype");
}
Value *ScalarExprEmitter::VisitAtomicExpr(AtomicExpr *E) {
return CGF.EmitAtomicExpr(E).getScalarVal();
}
//===----------------------------------------------------------------------===//
// 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");
if (isa<CXXDefaultArgExpr>(E))
disableDebugInfo();
Value *V = ScalarExprEmitter(*this, IgnoreResultAssign)
.Visit(const_cast<Expr*>(E));
if (isa<CXXDefaultArgExpr>(E))
enableDebugInfo();
return V;
}
/// 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);
}
llvm::Value *CodeGenFunction::
EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
bool isInc, bool isPre) {
return ScalarExprEmitter(*this).EmitScalarPrePostIncDec(E, LV, isInc, isPre);
}
LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) {
llvm::Value *V;
// object->isa or (*object).isa
// Generate code as for: *(Class*)object
// build Class* type
llvm::Type *ClassPtrTy = ConvertType(E->getType());
Expr *BaseExpr = E->getBase();
if (BaseExpr->isRValue()) {
V = CreateTempAlloca(ClassPtrTy, "resval");
llvm::Value *Src = EmitScalarExpr(BaseExpr);
Builder.CreateStore(Src, V);
V = ScalarExprEmitter(*this).EmitLoadOfLValue(
MakeAddrLValue(V, E->getType()));
} else {
if (E->isArrow())
V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr);
else
V = EmitLValue(BaseExpr).getAddress();
}
// build Class* type
ClassPtrTy = ClassPtrTy->getPointerTo();
V = Builder.CreateBitCast(V, ClassPtrTy);
return MakeAddrLValue(V, E->getType());
}
LValue CodeGenFunction::EmitCompoundAssignmentLValue(
const CompoundAssignOperator *E) {
ScalarExprEmitter Scalar(*this);
Value *Result = 0;
switch (E->getOpcode()) {
#define COMPOUND_OP(Op) \
case BO_##Op##Assign: \
return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \
Result)
COMPOUND_OP(Mul);
COMPOUND_OP(Div);
COMPOUND_OP(Rem);
COMPOUND_OP(Add);
COMPOUND_OP(Sub);
COMPOUND_OP(Shl);
COMPOUND_OP(Shr);
COMPOUND_OP(And);
COMPOUND_OP(Xor);
COMPOUND_OP(Or);
#undef COMPOUND_OP
case BO_PtrMemD:
case BO_PtrMemI:
case BO_Mul:
case BO_Div:
case BO_Rem:
case BO_Add:
case BO_Sub:
case BO_Shl:
case BO_Shr:
case BO_LT:
case BO_GT:
case BO_LE:
case BO_GE:
case BO_EQ:
case BO_NE:
case BO_And:
case BO_Xor:
case BO_Or:
case BO_LAnd:
case BO_LOr:
case BO_Assign:
case BO_Comma:
llvm_unreachable("Not valid compound assignment operators");
}
llvm_unreachable("Unhandled compound assignment operator");
}
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