1 //===--- CGExprScalar.cpp - Emit LLVM Code for Scalar Exprs ---------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This contains code to emit Expr nodes with scalar LLVM types as LLVM code.
12 //===----------------------------------------------------------------------===//
14 #include "CodeGenFunction.h"
15 #include "CGObjCRuntime.h"
16 #include "CodeGenModule.h"
17 #include "clang/AST/ASTContext.h"
18 #include "clang/AST/DeclObjC.h"
19 #include "clang/AST/RecordLayout.h"
20 #include "clang/AST/StmtVisitor.h"
21 #include "clang/Basic/TargetInfo.h"
22 #include "llvm/Constants.h"
23 #include "llvm/Function.h"
24 #include "llvm/GlobalVariable.h"
25 #include "llvm/Intrinsics.h"
26 #include "llvm/Module.h"
27 #include "llvm/Support/CFG.h"
28 #include "llvm/Target/TargetData.h"
31 using namespace clang;
32 using namespace CodeGen;
35 //===----------------------------------------------------------------------===//
36 // Scalar Expression Emitter
37 //===----------------------------------------------------------------------===//
42 QualType Ty; // Computation Type.
43 const BinaryOperator *E;
47 class ScalarExprEmitter
48 : public StmtVisitor<ScalarExprEmitter, Value*> {
51 bool IgnoreResultAssign;
52 llvm::LLVMContext &VMContext;
55 ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false)
56 : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira),
57 VMContext(cgf.getLLVMContext()) {
60 //===--------------------------------------------------------------------===//
62 //===--------------------------------------------------------------------===//
64 bool TestAndClearIgnoreResultAssign() {
65 bool I = IgnoreResultAssign;
66 IgnoreResultAssign = false;
70 const llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); }
71 LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); }
72 LValue EmitCheckedLValue(const Expr *E) { return CGF.EmitCheckedLValue(E); }
74 Value *EmitLoadOfLValue(LValue LV, QualType T) {
75 return CGF.EmitLoadOfLValue(LV, T).getScalarVal();
78 /// EmitLoadOfLValue - Given an expression with complex type that represents a
79 /// value l-value, this method emits the address of the l-value, then loads
80 /// and returns the result.
81 Value *EmitLoadOfLValue(const Expr *E) {
82 return EmitLoadOfLValue(EmitCheckedLValue(E), E->getType());
85 /// EmitConversionToBool - Convert the specified expression value to a
86 /// boolean (i1) truth value. This is equivalent to "Val != 0".
87 Value *EmitConversionToBool(Value *Src, QualType DstTy);
89 /// EmitScalarConversion - Emit a conversion from the specified type to the
90 /// specified destination type, both of which are LLVM scalar types.
91 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy);
93 /// EmitComplexToScalarConversion - Emit a conversion from the specified
94 /// complex type to the specified destination type, where the destination type
95 /// is an LLVM scalar type.
96 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src,
97 QualType SrcTy, QualType DstTy);
99 //===--------------------------------------------------------------------===//
101 //===--------------------------------------------------------------------===//
103 Value *VisitStmt(Stmt *S) {
104 S->dump(CGF.getContext().getSourceManager());
105 assert(0 && "Stmt can't have complex result type!");
108 Value *VisitExpr(Expr *S);
110 Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); }
113 Value *VisitIntegerLiteral(const IntegerLiteral *E) {
114 return llvm::ConstantInt::get(VMContext, E->getValue());
116 Value *VisitFloatingLiteral(const FloatingLiteral *E) {
117 return llvm::ConstantFP::get(VMContext, E->getValue());
119 Value *VisitCharacterLiteral(const CharacterLiteral *E) {
120 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
122 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) {
123 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
125 Value *VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) {
126 return llvm::Constant::getNullValue(ConvertType(E->getType()));
128 Value *VisitGNUNullExpr(const GNUNullExpr *E) {
129 return llvm::Constant::getNullValue(ConvertType(E->getType()));
131 Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) {
132 return llvm::ConstantInt::get(ConvertType(E->getType()),
133 CGF.getContext().typesAreCompatible(
134 E->getArgType1(), E->getArgType2()));
136 Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E);
137 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) {
138 llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel());
139 return Builder.CreateBitCast(V, ConvertType(E->getType()));
143 Value *VisitDeclRefExpr(DeclRefExpr *E) {
144 Expr::EvalResult Result;
145 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) {
146 assert(!Result.HasSideEffects && "Constant declref with side-effect?!");
147 return llvm::ConstantInt::get(VMContext, Result.Val.getInt());
149 return EmitLoadOfLValue(E);
151 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) {
152 return CGF.EmitObjCSelectorExpr(E);
154 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) {
155 return CGF.EmitObjCProtocolExpr(E);
157 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
158 return EmitLoadOfLValue(E);
160 Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
161 return EmitLoadOfLValue(E);
163 Value *VisitObjCImplicitSetterGetterRefExpr(
164 ObjCImplicitSetterGetterRefExpr *E) {
165 return EmitLoadOfLValue(E);
167 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) {
168 return CGF.EmitObjCMessageExpr(E).getScalarVal();
171 Value *VisitObjCIsaExpr(ObjCIsaExpr *E) {
172 LValue LV = CGF.EmitObjCIsaExpr(E);
173 Value *V = CGF.EmitLoadOfLValue(LV, E->getType()).getScalarVal();
177 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E);
178 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E);
179 Value *VisitMemberExpr(MemberExpr *E);
180 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); }
181 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
182 return EmitLoadOfLValue(E);
185 Value *VisitInitListExpr(InitListExpr *E);
187 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) {
188 return llvm::Constant::getNullValue(ConvertType(E->getType()));
190 Value *VisitCastExpr(CastExpr *E) {
191 // Make sure to evaluate VLA bounds now so that we have them for later.
192 if (E->getType()->isVariablyModifiedType())
193 CGF.EmitVLASize(E->getType());
195 return EmitCastExpr(E);
197 Value *EmitCastExpr(CastExpr *E);
199 Value *VisitCallExpr(const CallExpr *E) {
200 if (E->getCallReturnType()->isReferenceType())
201 return EmitLoadOfLValue(E);
203 return CGF.EmitCallExpr(E).getScalarVal();
206 Value *VisitStmtExpr(const StmtExpr *E);
208 Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E);
211 Value *VisitPrePostIncDec(const UnaryOperator *E, bool isInc, bool isPre) {
212 LValue LV = EmitLValue(E->getSubExpr());
213 return CGF.EmitScalarPrePostIncDec(E, LV, isInc, isPre);
215 Value *VisitUnaryPostDec(const UnaryOperator *E) {
216 return VisitPrePostIncDec(E, false, false);
218 Value *VisitUnaryPostInc(const UnaryOperator *E) {
219 return VisitPrePostIncDec(E, true, false);
221 Value *VisitUnaryPreDec(const UnaryOperator *E) {
222 return VisitPrePostIncDec(E, false, true);
224 Value *VisitUnaryPreInc(const UnaryOperator *E) {
225 return VisitPrePostIncDec(E, true, true);
227 Value *VisitUnaryAddrOf(const UnaryOperator *E) {
228 return EmitLValue(E->getSubExpr()).getAddress();
230 Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
231 Value *VisitUnaryPlus(const UnaryOperator *E) {
232 // This differs from gcc, though, most likely due to a bug in gcc.
233 TestAndClearIgnoreResultAssign();
234 return Visit(E->getSubExpr());
236 Value *VisitUnaryMinus (const UnaryOperator *E);
237 Value *VisitUnaryNot (const UnaryOperator *E);
238 Value *VisitUnaryLNot (const UnaryOperator *E);
239 Value *VisitUnaryReal (const UnaryOperator *E);
240 Value *VisitUnaryImag (const UnaryOperator *E);
241 Value *VisitUnaryExtension(const UnaryOperator *E) {
242 return Visit(E->getSubExpr());
244 Value *VisitUnaryOffsetOf(const UnaryOperator *E);
247 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
248 return Visit(DAE->getExpr());
250 Value *VisitCXXThisExpr(CXXThisExpr *TE) {
251 return CGF.LoadCXXThis();
254 Value *VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) {
255 return CGF.EmitCXXExprWithTemporaries(E).getScalarVal();
257 Value *VisitCXXNewExpr(const CXXNewExpr *E) {
258 return CGF.EmitCXXNewExpr(E);
260 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) {
261 CGF.EmitCXXDeleteExpr(E);
264 Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) {
265 return llvm::ConstantInt::get(Builder.getInt1Ty(),
266 E->EvaluateTrait(CGF.getContext()));
269 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) {
270 // C++ [expr.pseudo]p1:
271 // The result shall only be used as the operand for the function call
272 // operator (), and the result of such a call has type void. The only
273 // effect is the evaluation of the postfix-expression before the dot or
275 CGF.EmitScalarExpr(E->getBase());
279 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) {
280 return llvm::Constant::getNullValue(ConvertType(E->getType()));
283 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) {
284 CGF.EmitCXXThrowExpr(E);
289 Value *EmitMul(const BinOpInfo &Ops) {
290 if (CGF.getContext().getLangOptions().OverflowChecking
291 && Ops.Ty->isSignedIntegerType())
292 return EmitOverflowCheckedBinOp(Ops);
293 if (Ops.LHS->getType()->isFPOrFPVectorTy())
294 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul");
295 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul");
297 /// Create a binary op that checks for overflow.
298 /// Currently only supports +, - and *.
299 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops);
300 Value *EmitDiv(const BinOpInfo &Ops);
301 Value *EmitRem(const BinOpInfo &Ops);
302 Value *EmitAdd(const BinOpInfo &Ops);
303 Value *EmitSub(const BinOpInfo &Ops);
304 Value *EmitShl(const BinOpInfo &Ops);
305 Value *EmitShr(const BinOpInfo &Ops);
306 Value *EmitAnd(const BinOpInfo &Ops) {
307 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and");
309 Value *EmitXor(const BinOpInfo &Ops) {
310 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor");
312 Value *EmitOr (const BinOpInfo &Ops) {
313 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or");
316 BinOpInfo EmitBinOps(const BinaryOperator *E);
317 Value *EmitCompoundAssign(const CompoundAssignOperator *E,
318 Value *(ScalarExprEmitter::*F)(const BinOpInfo &));
320 // Binary operators and binary compound assignment operators.
321 #define HANDLEBINOP(OP) \
322 Value *VisitBin ## OP(const BinaryOperator *E) { \
323 return Emit ## OP(EmitBinOps(E)); \
325 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \
326 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \
341 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc,
342 unsigned SICmpOpc, unsigned FCmpOpc);
343 #define VISITCOMP(CODE, UI, SI, FP) \
344 Value *VisitBin##CODE(const BinaryOperator *E) { \
345 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \
346 llvm::FCmpInst::FP); }
347 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT)
348 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT)
349 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE)
350 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE)
351 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ)
352 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE)
355 Value *VisitBinAssign (const BinaryOperator *E);
357 Value *VisitBinLAnd (const BinaryOperator *E);
358 Value *VisitBinLOr (const BinaryOperator *E);
359 Value *VisitBinComma (const BinaryOperator *E);
361 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); }
362 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); }
365 Value *VisitBlockExpr(const BlockExpr *BE);
366 Value *VisitConditionalOperator(const ConditionalOperator *CO);
367 Value *VisitChooseExpr(ChooseExpr *CE);
368 Value *VisitVAArgExpr(VAArgExpr *VE);
369 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) {
370 return CGF.EmitObjCStringLiteral(E);
373 } // end anonymous namespace.
375 //===----------------------------------------------------------------------===//
377 //===----------------------------------------------------------------------===//
379 /// EmitConversionToBool - Convert the specified expression value to a
380 /// boolean (i1) truth value. This is equivalent to "Val != 0".
381 Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) {
382 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs");
384 if (SrcType->isRealFloatingType()) {
385 // Compare against 0.0 for fp scalars.
386 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType());
387 return Builder.CreateFCmpUNE(Src, Zero, "tobool");
390 if (SrcType->isMemberPointerType()) {
391 // Compare against -1.
392 llvm::Value *NegativeOne = llvm::Constant::getAllOnesValue(Src->getType());
393 return Builder.CreateICmpNE(Src, NegativeOne, "tobool");
396 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) &&
397 "Unknown scalar type to convert");
399 // Because of the type rules of C, we often end up computing a logical value,
400 // then zero extending it to int, then wanting it as a logical value again.
401 // Optimize this common case.
402 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) {
403 if (ZI->getOperand(0)->getType() ==
404 llvm::Type::getInt1Ty(CGF.getLLVMContext())) {
405 Value *Result = ZI->getOperand(0);
406 // If there aren't any more uses, zap the instruction to save space.
407 // Note that there can be more uses, for example if this
408 // is the result of an assignment.
410 ZI->eraseFromParent();
415 // Compare against an integer or pointer null.
416 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType());
417 return Builder.CreateICmpNE(Src, Zero, "tobool");
420 /// EmitScalarConversion - Emit a conversion from the specified type to the
421 /// specified destination type, both of which are LLVM scalar types.
422 Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType,
424 SrcType = CGF.getContext().getCanonicalType(SrcType);
425 DstType = CGF.getContext().getCanonicalType(DstType);
426 if (SrcType == DstType) return Src;
428 if (DstType->isVoidType()) return 0;
430 llvm::LLVMContext &VMContext = CGF.getLLVMContext();
432 // Handle conversions to bool first, they are special: comparisons against 0.
433 if (DstType->isBooleanType())
434 return EmitConversionToBool(Src, SrcType);
436 const llvm::Type *DstTy = ConvertType(DstType);
438 // Ignore conversions like int -> uint.
439 if (Src->getType() == DstTy)
442 // Handle pointer conversions next: pointers can only be converted to/from
443 // other pointers and integers. Check for pointer types in terms of LLVM, as
444 // some native types (like Obj-C id) may map to a pointer type.
445 if (isa<llvm::PointerType>(DstTy)) {
446 // The source value may be an integer, or a pointer.
447 if (isa<llvm::PointerType>(Src->getType()))
448 return Builder.CreateBitCast(Src, DstTy, "conv");
450 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?");
451 // First, convert to the correct width so that we control the kind of
453 const llvm::Type *MiddleTy =
454 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth);
455 bool InputSigned = SrcType->isSignedIntegerType();
456 llvm::Value* IntResult =
457 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv");
458 // Then, cast to pointer.
459 return Builder.CreateIntToPtr(IntResult, DstTy, "conv");
462 if (isa<llvm::PointerType>(Src->getType())) {
463 // Must be an ptr to int cast.
464 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?");
465 return Builder.CreatePtrToInt(Src, DstTy, "conv");
468 // A scalar can be splatted to an extended vector of the same element type
469 if (DstType->isExtVectorType() && !SrcType->isVectorType()) {
470 // Cast the scalar to element type
471 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType();
472 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy);
474 // Insert the element in element zero of an undef vector
475 llvm::Value *UnV = llvm::UndefValue::get(DstTy);
477 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0);
478 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp");
480 // Splat the element across to all elements
481 llvm::SmallVector<llvm::Constant*, 16> Args;
482 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements();
483 for (unsigned i = 0; i < NumElements; i++)
484 Args.push_back(llvm::ConstantInt::get(
485 llvm::Type::getInt32Ty(VMContext), 0));
487 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements);
488 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat");
492 // Allow bitcast from vector to integer/fp of the same size.
493 if (isa<llvm::VectorType>(Src->getType()) ||
494 isa<llvm::VectorType>(DstTy))
495 return Builder.CreateBitCast(Src, DstTy, "conv");
497 // Finally, we have the arithmetic types: real int/float.
498 if (isa<llvm::IntegerType>(Src->getType())) {
499 bool InputSigned = SrcType->isSignedIntegerType();
500 if (isa<llvm::IntegerType>(DstTy))
501 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv");
502 else if (InputSigned)
503 return Builder.CreateSIToFP(Src, DstTy, "conv");
505 return Builder.CreateUIToFP(Src, DstTy, "conv");
508 assert(Src->getType()->isFloatingPointTy() && "Unknown real conversion");
509 if (isa<llvm::IntegerType>(DstTy)) {
510 if (DstType->isSignedIntegerType())
511 return Builder.CreateFPToSI(Src, DstTy, "conv");
513 return Builder.CreateFPToUI(Src, DstTy, "conv");
516 assert(DstTy->isFloatingPointTy() && "Unknown real conversion");
517 if (DstTy->getTypeID() < Src->getType()->getTypeID())
518 return Builder.CreateFPTrunc(Src, DstTy, "conv");
520 return Builder.CreateFPExt(Src, DstTy, "conv");
523 /// EmitComplexToScalarConversion - Emit a conversion from the specified complex
524 /// type to the specified destination type, where the destination type is an
525 /// LLVM scalar type.
526 Value *ScalarExprEmitter::
527 EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src,
528 QualType SrcTy, QualType DstTy) {
529 // Get the source element type.
530 SrcTy = SrcTy->getAs<ComplexType>()->getElementType();
532 // Handle conversions to bool first, they are special: comparisons against 0.
533 if (DstTy->isBooleanType()) {
534 // Complex != 0 -> (Real != 0) | (Imag != 0)
535 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy);
536 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy);
537 return Builder.CreateOr(Src.first, Src.second, "tobool");
540 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type,
541 // the imaginary part of the complex value is discarded and the value of the
542 // real part is converted according to the conversion rules for the
543 // corresponding real type.
544 return EmitScalarConversion(Src.first, SrcTy, DstTy);
548 //===----------------------------------------------------------------------===//
550 //===----------------------------------------------------------------------===//
552 Value *ScalarExprEmitter::VisitExpr(Expr *E) {
553 CGF.ErrorUnsupported(E, "scalar expression");
554 if (E->getType()->isVoidType())
556 return llvm::UndefValue::get(CGF.ConvertType(E->getType()));
559 Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) {
560 llvm::SmallVector<llvm::Constant*, 32> indices;
561 for (unsigned i = 2; i < E->getNumSubExprs(); i++) {
562 indices.push_back(cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i))));
564 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0));
565 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1));
566 Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size());
567 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle");
569 Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) {
570 Expr::EvalResult Result;
571 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) {
573 CGF.EmitScalarExpr(E->getBase());
575 EmitLValue(E->getBase());
576 return llvm::ConstantInt::get(VMContext, Result.Val.getInt());
578 return EmitLoadOfLValue(E);
581 Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
582 TestAndClearIgnoreResultAssign();
584 // Emit subscript expressions in rvalue context's. For most cases, this just
585 // loads the lvalue formed by the subscript expr. However, we have to be
586 // careful, because the base of a vector subscript is occasionally an rvalue,
587 // so we can't get it as an lvalue.
588 if (!E->getBase()->getType()->isVectorType())
589 return EmitLoadOfLValue(E);
591 // Handle the vector case. The base must be a vector, the index must be an
593 Value *Base = Visit(E->getBase());
594 Value *Idx = Visit(E->getIdx());
595 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerType();
596 Idx = Builder.CreateIntCast(Idx,
597 llvm::Type::getInt32Ty(CGF.getLLVMContext()),
600 return Builder.CreateExtractElement(Base, Idx, "vecext");
603 static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx,
604 unsigned Off, const llvm::Type *I32Ty) {
605 int MV = SVI->getMaskValue(Idx);
607 return llvm::UndefValue::get(I32Ty);
608 return llvm::ConstantInt::get(I32Ty, Off+MV);
611 Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) {
612 bool Ignore = TestAndClearIgnoreResultAssign();
614 assert (Ignore == false && "init list ignored");
615 unsigned NumInitElements = E->getNumInits();
617 if (E->hadArrayRangeDesignator())
618 CGF.ErrorUnsupported(E, "GNU array range designator extension");
620 const llvm::VectorType *VType =
621 dyn_cast<llvm::VectorType>(ConvertType(E->getType()));
623 // We have a scalar in braces. Just use the first element.
625 return Visit(E->getInit(0));
627 unsigned ResElts = VType->getNumElements();
628 const llvm::Type *I32Ty = llvm::Type::getInt32Ty(CGF.getLLVMContext());
630 // Loop over initializers collecting the Value for each, and remembering
631 // whether the source was swizzle (ExtVectorElementExpr). This will allow
632 // us to fold the shuffle for the swizzle into the shuffle for the vector
633 // initializer, since LLVM optimizers generally do not want to touch
636 bool VIsUndefShuffle = false;
637 llvm::Value *V = llvm::UndefValue::get(VType);
638 for (unsigned i = 0; i != NumInitElements; ++i) {
639 Expr *IE = E->getInit(i);
640 Value *Init = Visit(IE);
641 llvm::SmallVector<llvm::Constant*, 16> Args;
643 const llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType());
645 // Handle scalar elements. If the scalar initializer is actually one
646 // element of a different vector of the same width, use shuffle instead of
649 if (isa<ExtVectorElementExpr>(IE)) {
650 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init);
652 if (EI->getVectorOperandType()->getNumElements() == ResElts) {
653 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand());
654 Value *LHS = 0, *RHS = 0;
656 // insert into undef -> shuffle (src, undef)
658 for (unsigned j = 1; j != ResElts; ++j)
659 Args.push_back(llvm::UndefValue::get(I32Ty));
661 LHS = EI->getVectorOperand();
663 VIsUndefShuffle = true;
664 } else if (VIsUndefShuffle) {
665 // insert into undefshuffle && size match -> shuffle (v, src)
666 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V);
667 for (unsigned j = 0; j != CurIdx; ++j)
668 Args.push_back(getMaskElt(SVV, j, 0, I32Ty));
669 Args.push_back(llvm::ConstantInt::get(I32Ty,
670 ResElts + C->getZExtValue()));
671 for (unsigned j = CurIdx + 1; j != ResElts; ++j)
672 Args.push_back(llvm::UndefValue::get(I32Ty));
674 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0);
675 RHS = EI->getVectorOperand();
676 VIsUndefShuffle = false;
679 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts);
680 V = Builder.CreateShuffleVector(LHS, RHS, Mask);
686 Value *Idx = llvm::ConstantInt::get(I32Ty, CurIdx);
687 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit");
688 VIsUndefShuffle = false;
693 unsigned InitElts = VVT->getNumElements();
695 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's
696 // input is the same width as the vector being constructed, generate an
697 // optimized shuffle of the swizzle input into the result.
698 unsigned Offset = (CurIdx == 0) ? 0 : ResElts;
699 if (isa<ExtVectorElementExpr>(IE)) {
700 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init);
701 Value *SVOp = SVI->getOperand(0);
702 const llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType());
704 if (OpTy->getNumElements() == ResElts) {
705 for (unsigned j = 0; j != CurIdx; ++j) {
706 // If the current vector initializer is a shuffle with undef, merge
707 // this shuffle directly into it.
708 if (VIsUndefShuffle) {
709 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0,
712 Args.push_back(llvm::ConstantInt::get(I32Ty, j));
715 for (unsigned j = 0, je = InitElts; j != je; ++j)
716 Args.push_back(getMaskElt(SVI, j, Offset, I32Ty));
717 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j)
718 Args.push_back(llvm::UndefValue::get(I32Ty));
721 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0);
727 // Extend init to result vector length, and then shuffle its contribution
728 // to the vector initializer into V.
730 for (unsigned j = 0; j != InitElts; ++j)
731 Args.push_back(llvm::ConstantInt::get(I32Ty, j));
732 for (unsigned j = InitElts; j != ResElts; ++j)
733 Args.push_back(llvm::UndefValue::get(I32Ty));
734 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts);
735 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT),
739 for (unsigned j = 0; j != CurIdx; ++j)
740 Args.push_back(llvm::ConstantInt::get(I32Ty, j));
741 for (unsigned j = 0; j != InitElts; ++j)
742 Args.push_back(llvm::ConstantInt::get(I32Ty, j+Offset));
743 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j)
744 Args.push_back(llvm::UndefValue::get(I32Ty));
747 // If V is undef, make sure it ends up on the RHS of the shuffle to aid
748 // merging subsequent shuffles into this one.
751 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts);
752 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit");
753 VIsUndefShuffle = isa<llvm::UndefValue>(Init);
757 // FIXME: evaluate codegen vs. shuffling against constant null vector.
758 // Emit remaining default initializers.
759 const llvm::Type *EltTy = VType->getElementType();
761 // Emit remaining default initializers
762 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) {
763 Value *Idx = llvm::ConstantInt::get(I32Ty, CurIdx);
764 llvm::Value *Init = llvm::Constant::getNullValue(EltTy);
765 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit");
770 static bool ShouldNullCheckClassCastValue(const CastExpr *CE) {
771 const Expr *E = CE->getSubExpr();
773 if (isa<CXXThisExpr>(E)) {
774 // We always assume that 'this' is never null.
778 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) {
779 // And that lvalue casts are never null.
780 if (ICE->isLvalueCast())
787 // VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts
788 // have to handle a more broad range of conversions than explicit casts, as they
789 // handle things like function to ptr-to-function decay etc.
790 Value *ScalarExprEmitter::EmitCastExpr(CastExpr *CE) {
791 Expr *E = CE->getSubExpr();
792 QualType DestTy = CE->getType();
793 CastExpr::CastKind Kind = CE->getCastKind();
795 if (!DestTy->isVoidType())
796 TestAndClearIgnoreResultAssign();
798 // Since almost all cast kinds apply to scalars, this switch doesn't have
799 // a default case, so the compiler will warn on a missing case. The cases
800 // are in the same order as in the CastKind enum.
802 case CastExpr::CK_Unknown:
803 // FIXME: All casts should have a known kind!
804 //assert(0 && "Unknown cast kind!");
807 case CastExpr::CK_AnyPointerToObjCPointerCast:
808 case CastExpr::CK_AnyPointerToBlockPointerCast:
809 case CastExpr::CK_BitCast: {
810 Value *Src = Visit(const_cast<Expr*>(E));
811 return Builder.CreateBitCast(Src, ConvertType(DestTy));
813 case CastExpr::CK_NoOp:
814 case CastExpr::CK_UserDefinedConversion:
815 return Visit(const_cast<Expr*>(E));
817 case CastExpr::CK_BaseToDerived: {
818 const CXXRecordDecl *BaseClassDecl =
819 E->getType()->getCXXRecordDeclForPointerType();
820 const CXXRecordDecl *DerivedClassDecl =
821 DestTy->getCXXRecordDeclForPointerType();
823 Value *Src = Visit(const_cast<Expr*>(E));
825 bool NullCheckValue = ShouldNullCheckClassCastValue(CE);
826 return CGF.GetAddressOfDerivedClass(Src, BaseClassDecl, DerivedClassDecl,
829 case CastExpr::CK_DerivedToBase: {
830 const RecordType *DerivedClassTy =
831 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>();
832 CXXRecordDecl *DerivedClassDecl =
833 cast<CXXRecordDecl>(DerivedClassTy->getDecl());
835 const RecordType *BaseClassTy =
836 DestTy->getAs<PointerType>()->getPointeeType()->getAs<RecordType>();
837 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseClassTy->getDecl());
839 Value *Src = Visit(const_cast<Expr*>(E));
841 bool NullCheckValue = ShouldNullCheckClassCastValue(CE);
842 return CGF.GetAddressOfBaseClass(Src, DerivedClassDecl, BaseClassDecl,
845 case CastExpr::CK_Dynamic: {
846 Value *V = Visit(const_cast<Expr*>(E));
847 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE);
848 return CGF.EmitDynamicCast(V, DCE);
850 case CastExpr::CK_ToUnion:
851 assert(0 && "Should be unreachable!");
854 case CastExpr::CK_ArrayToPointerDecay: {
855 assert(E->getType()->isArrayType() &&
856 "Array to pointer decay must have array source type!");
858 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays.
860 // Note that VLA pointers are always decayed, so we don't need to do
862 if (!E->getType()->isVariableArrayType()) {
863 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer");
864 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType())
865 ->getElementType()) &&
866 "Expected pointer to array");
867 V = Builder.CreateStructGEP(V, 0, "arraydecay");
872 case CastExpr::CK_FunctionToPointerDecay:
873 return EmitLValue(E).getAddress();
875 case CastExpr::CK_NullToMemberPointer:
876 return CGF.CGM.EmitNullConstant(DestTy);
878 case CastExpr::CK_BaseToDerivedMemberPointer:
879 case CastExpr::CK_DerivedToBaseMemberPointer: {
880 Value *Src = Visit(E);
882 // See if we need to adjust the pointer.
883 const CXXRecordDecl *BaseDecl =
884 cast<CXXRecordDecl>(E->getType()->getAs<MemberPointerType>()->
885 getClass()->getAs<RecordType>()->getDecl());
886 const CXXRecordDecl *DerivedDecl =
887 cast<CXXRecordDecl>(CE->getType()->getAs<MemberPointerType>()->
888 getClass()->getAs<RecordType>()->getDecl());
889 if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer)
890 std::swap(DerivedDecl, BaseDecl);
892 if (llvm::Constant *Adj =
893 CGF.CGM.GetNonVirtualBaseClassOffset(DerivedDecl, BaseDecl)) {
894 if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer)
895 Src = Builder.CreateSub(Src, Adj, "adj");
897 Src = Builder.CreateAdd(Src, Adj, "adj");
902 case CastExpr::CK_ConstructorConversion:
903 assert(0 && "Should be unreachable!");
906 case CastExpr::CK_IntegralToPointer: {
907 Value *Src = Visit(const_cast<Expr*>(E));
909 // First, convert to the correct width so that we control the kind of
911 const llvm::Type *MiddleTy =
912 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth);
913 bool InputSigned = E->getType()->isSignedIntegerType();
914 llvm::Value* IntResult =
915 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv");
917 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy));
919 case CastExpr::CK_PointerToIntegral: {
920 Value *Src = Visit(const_cast<Expr*>(E));
921 return Builder.CreatePtrToInt(Src, ConvertType(DestTy));
923 case CastExpr::CK_ToVoid: {
924 CGF.EmitAnyExpr(E, 0, false, true);
927 case CastExpr::CK_VectorSplat: {
928 const llvm::Type *DstTy = ConvertType(DestTy);
929 Value *Elt = Visit(const_cast<Expr*>(E));
931 // Insert the element in element zero of an undef vector
932 llvm::Value *UnV = llvm::UndefValue::get(DstTy);
934 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0);
935 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp");
937 // Splat the element across to all elements
938 llvm::SmallVector<llvm::Constant*, 16> Args;
939 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements();
940 for (unsigned i = 0; i < NumElements; i++)
941 Args.push_back(llvm::ConstantInt::get(
942 llvm::Type::getInt32Ty(VMContext), 0));
944 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements);
945 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat");
948 case CastExpr::CK_IntegralCast:
949 case CastExpr::CK_IntegralToFloating:
950 case CastExpr::CK_FloatingToIntegral:
951 case CastExpr::CK_FloatingCast:
952 return EmitScalarConversion(Visit(E), E->getType(), DestTy);
954 case CastExpr::CK_MemberPointerToBoolean:
955 return CGF.EvaluateExprAsBool(E);
958 // Handle cases where the source is an non-complex type.
960 if (!CGF.hasAggregateLLVMType(E->getType())) {
961 Value *Src = Visit(const_cast<Expr*>(E));
963 // Use EmitScalarConversion to perform the conversion.
964 return EmitScalarConversion(Src, E->getType(), DestTy);
967 if (E->getType()->isAnyComplexType()) {
968 // Handle cases where the source is a complex type.
969 bool IgnoreImag = true;
970 bool IgnoreImagAssign = true;
971 bool IgnoreReal = IgnoreResultAssign;
972 bool IgnoreRealAssign = IgnoreResultAssign;
973 if (DestTy->isBooleanType())
974 IgnoreImagAssign = IgnoreImag = false;
975 else if (DestTy->isVoidType()) {
976 IgnoreReal = IgnoreImag = false;
977 IgnoreRealAssign = IgnoreImagAssign = true;
979 CodeGenFunction::ComplexPairTy V
980 = CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign,
982 return EmitComplexToScalarConversion(V, E->getType(), DestTy);
985 // Okay, this is a cast from an aggregate. It must be a cast to void. Just
986 // evaluate the result and return.
987 CGF.EmitAggExpr(E, 0, false, true);
991 Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) {
992 return CGF.EmitCompoundStmt(*E->getSubStmt(),
993 !E->getType()->isVoidType()).getScalarVal();
996 Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) {
997 llvm::Value *V = CGF.GetAddrOfBlockDecl(E);
998 if (E->getType().isObjCGCWeak())
999 return CGF.CGM.getObjCRuntime().EmitObjCWeakRead(CGF, V);
1000 return Builder.CreateLoad(V, "tmp");
1003 //===----------------------------------------------------------------------===//
1005 //===----------------------------------------------------------------------===//
1007 Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
1008 TestAndClearIgnoreResultAssign();
1009 Value *Op = Visit(E->getSubExpr());
1010 if (Op->getType()->isFPOrFPVectorTy())
1011 return Builder.CreateFNeg(Op, "neg");
1012 return Builder.CreateNeg(Op, "neg");
1015 Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
1016 TestAndClearIgnoreResultAssign();
1017 Value *Op = Visit(E->getSubExpr());
1018 return Builder.CreateNot(Op, "neg");
1021 Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) {
1022 // Compare operand to zero.
1023 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr());
1026 // TODO: Could dynamically modify easy computations here. For example, if
1027 // the operand is an icmp ne, turn into icmp eq.
1028 BoolVal = Builder.CreateNot(BoolVal, "lnot");
1030 // ZExt result to the expr type.
1031 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext");
1034 /// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of
1035 /// argument of the sizeof expression as an integer.
1037 ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) {
1038 QualType TypeToSize = E->getTypeOfArgument();
1039 if (E->isSizeOf()) {
1040 if (const VariableArrayType *VAT =
1041 CGF.getContext().getAsVariableArrayType(TypeToSize)) {
1042 if (E->isArgumentType()) {
1043 // sizeof(type) - make sure to emit the VLA size.
1044 CGF.EmitVLASize(TypeToSize);
1046 // C99 6.5.3.4p2: If the argument is an expression of type
1047 // VLA, it is evaluated.
1048 CGF.EmitAnyExpr(E->getArgumentExpr());
1051 return CGF.GetVLASize(VAT);
1055 // If this isn't sizeof(vla), the result must be constant; use the constant
1056 // folding logic so we don't have to duplicate it here.
1057 Expr::EvalResult Result;
1058 E->Evaluate(Result, CGF.getContext());
1059 return llvm::ConstantInt::get(VMContext, Result.Val.getInt());
1062 Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) {
1063 Expr *Op = E->getSubExpr();
1064 if (Op->getType()->isAnyComplexType())
1065 return CGF.EmitComplexExpr(Op, false, true, false, true).first;
1068 Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) {
1069 Expr *Op = E->getSubExpr();
1070 if (Op->getType()->isAnyComplexType())
1071 return CGF.EmitComplexExpr(Op, true, false, true, false).second;
1073 // __imag on a scalar returns zero. Emit the subexpr to ensure side
1074 // effects are evaluated, but not the actual value.
1075 if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid)
1078 CGF.EmitScalarExpr(Op, true);
1079 return llvm::Constant::getNullValue(ConvertType(E->getType()));
1082 Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) {
1083 Value* ResultAsPtr = EmitLValue(E->getSubExpr()).getAddress();
1084 const llvm::Type* ResultType = ConvertType(E->getType());
1085 return Builder.CreatePtrToInt(ResultAsPtr, ResultType, "offsetof");
1088 //===----------------------------------------------------------------------===//
1090 //===----------------------------------------------------------------------===//
1092 BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) {
1093 TestAndClearIgnoreResultAssign();
1095 Result.LHS = Visit(E->getLHS());
1096 Result.RHS = Visit(E->getRHS());
1097 Result.Ty = E->getType();
1102 Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E,
1103 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) {
1104 bool Ignore = TestAndClearIgnoreResultAssign();
1105 QualType LHSTy = E->getLHS()->getType();
1109 if (E->getComputationResultType()->isAnyComplexType()) {
1110 // This needs to go through the complex expression emitter, but it's a tad
1111 // complicated to do that... I'm leaving it out for now. (Note that we do
1112 // actually need the imaginary part of the RHS for multiplication and
1114 CGF.ErrorUnsupported(E, "complex compound assignment");
1115 return llvm::UndefValue::get(CGF.ConvertType(E->getType()));
1118 // Emit the RHS first. __block variables need to have the rhs evaluated
1119 // first, plus this should improve codegen a little.
1120 OpInfo.RHS = Visit(E->getRHS());
1121 OpInfo.Ty = E->getComputationResultType();
1123 // Load/convert the LHS.
1124 LValue LHSLV = EmitCheckedLValue(E->getLHS());
1125 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy);
1126 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy,
1127 E->getComputationLHSType());
1129 // Expand the binary operator.
1130 Value *Result = (this->*Func)(OpInfo);
1132 // Convert the result back to the LHS type.
1133 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy);
1135 // Store the result value into the LHS lvalue. Bit-fields are handled
1136 // specially because the result is altered by the store, i.e., [C99 6.5.16p1]
1137 // 'An assignment expression has the value of the left operand after the
1139 if (LHSLV.isBitfield()) {
1140 if (!LHSLV.isVolatileQualified()) {
1141 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy,
1145 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy);
1147 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy);
1150 return EmitLoadOfLValue(LHSLV, E->getType());
1154 Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) {
1155 if (Ops.LHS->getType()->isFPOrFPVectorTy())
1156 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div");
1157 else if (Ops.Ty->isUnsignedIntegerType())
1158 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div");
1160 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div");
1163 Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) {
1164 // Rem in C can't be a floating point type: C99 6.5.5p2.
1165 if (Ops.Ty->isUnsignedIntegerType())
1166 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem");
1168 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem");
1171 Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) {
1175 switch (Ops.E->getOpcode()) {
1176 case BinaryOperator::Add:
1177 case BinaryOperator::AddAssign:
1179 IID = llvm::Intrinsic::sadd_with_overflow;
1181 case BinaryOperator::Sub:
1182 case BinaryOperator::SubAssign:
1184 IID = llvm::Intrinsic::ssub_with_overflow;
1186 case BinaryOperator::Mul:
1187 case BinaryOperator::MulAssign:
1189 IID = llvm::Intrinsic::smul_with_overflow;
1192 assert(false && "Unsupported operation for overflow detection");
1198 const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty);
1200 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1);
1202 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS);
1203 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0);
1204 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1);
1206 // Branch in case of overflow.
1207 llvm::BasicBlock *initialBB = Builder.GetInsertBlock();
1208 llvm::BasicBlock *overflowBB =
1209 CGF.createBasicBlock("overflow", CGF.CurFn);
1210 llvm::BasicBlock *continueBB =
1211 CGF.createBasicBlock("overflow.continue", CGF.CurFn);
1213 Builder.CreateCondBr(overflow, overflowBB, continueBB);
1217 Builder.SetInsertPoint(overflowBB);
1220 // long long *__overflow_handler)(long long a, long long b, char op,
1222 std::vector<const llvm::Type*> handerArgTypes;
1223 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext));
1224 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext));
1225 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext));
1226 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext));
1227 llvm::FunctionType *handlerTy = llvm::FunctionType::get(
1228 llvm::Type::getInt64Ty(VMContext), handerArgTypes, false);
1229 llvm::Value *handlerFunction =
1230 CGF.CGM.getModule().getOrInsertGlobal("__overflow_handler",
1231 llvm::PointerType::getUnqual(handlerTy));
1232 handlerFunction = Builder.CreateLoad(handlerFunction);
1234 llvm::Value *handlerResult = Builder.CreateCall4(handlerFunction,
1235 Builder.CreateSExt(Ops.LHS, llvm::Type::getInt64Ty(VMContext)),
1236 Builder.CreateSExt(Ops.RHS, llvm::Type::getInt64Ty(VMContext)),
1237 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), OpID),
1238 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext),
1239 cast<llvm::IntegerType>(opTy)->getBitWidth()));
1241 handlerResult = Builder.CreateTrunc(handlerResult, opTy);
1243 Builder.CreateBr(continueBB);
1245 // Set up the continuation
1246 Builder.SetInsertPoint(continueBB);
1247 // Get the correct result
1248 llvm::PHINode *phi = Builder.CreatePHI(opTy);
1249 phi->reserveOperandSpace(2);
1250 phi->addIncoming(result, initialBB);
1251 phi->addIncoming(handlerResult, overflowBB);
1256 Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) {
1257 if (!Ops.Ty->isAnyPointerType()) {
1258 if (CGF.getContext().getLangOptions().OverflowChecking &&
1259 Ops.Ty->isSignedIntegerType())
1260 return EmitOverflowCheckedBinOp(Ops);
1262 if (Ops.LHS->getType()->isFPOrFPVectorTy())
1263 return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add");
1265 // Signed integer overflow is undefined behavior.
1266 if (Ops.Ty->isSignedIntegerType())
1267 return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add");
1269 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add");
1272 if (Ops.Ty->isPointerType() &&
1273 Ops.Ty->getAs<PointerType>()->isVariableArrayType()) {
1274 // The amount of the addition needs to account for the VLA size
1275 CGF.ErrorUnsupported(Ops.E, "VLA pointer addition");
1279 const PointerType *PT = Ops.E->getLHS()->getType()->getAs<PointerType>();
1280 const ObjCObjectPointerType *OPT =
1281 Ops.E->getLHS()->getType()->getAs<ObjCObjectPointerType>();
1285 IdxExp = Ops.E->getRHS();
1286 } else { // int + pointer
1287 PT = Ops.E->getRHS()->getType()->getAs<PointerType>();
1288 OPT = Ops.E->getRHS()->getType()->getAs<ObjCObjectPointerType>();
1289 assert((PT || OPT) && "Invalid add expr");
1292 IdxExp = Ops.E->getLHS();
1295 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth();
1296 if (Width < CGF.LLVMPointerWidth) {
1297 // Zero or sign extend the pointer value based on whether the index is
1299 const llvm::Type *IdxType =
1300 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth);
1301 if (IdxExp->getType()->isSignedIntegerType())
1302 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext");
1304 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext");
1306 const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType();
1307 // Handle interface types, which are not represented with a concrete type.
1308 if (const ObjCInterfaceType *OIT = dyn_cast<ObjCInterfaceType>(ElementType)) {
1309 llvm::Value *InterfaceSize =
1310 llvm::ConstantInt::get(Idx->getType(),
1311 CGF.getContext().getTypeSizeInChars(OIT).getQuantity());
1312 Idx = Builder.CreateMul(Idx, InterfaceSize);
1313 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext);
1314 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty);
1315 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr");
1316 return Builder.CreateBitCast(Res, Ptr->getType());
1319 // Explicitly handle GNU void* and function pointer arithmetic extensions. The
1320 // GNU void* casts amount to no-ops since our void* type is i8*, but this is
1322 if (ElementType->isVoidType() || ElementType->isFunctionType()) {
1323 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext);
1324 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty);
1325 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr");
1326 return Builder.CreateBitCast(Res, Ptr->getType());
1329 return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr");
1332 Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) {
1333 if (!isa<llvm::PointerType>(Ops.LHS->getType())) {
1334 if (CGF.getContext().getLangOptions().OverflowChecking
1335 && Ops.Ty->isSignedIntegerType())
1336 return EmitOverflowCheckedBinOp(Ops);
1338 if (Ops.LHS->getType()->isFPOrFPVectorTy())
1339 return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub");
1340 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub");
1343 if (Ops.E->getLHS()->getType()->isPointerType() &&
1344 Ops.E->getLHS()->getType()->getAs<PointerType>()->isVariableArrayType()) {
1345 // The amount of the addition needs to account for the VLA size for
1347 // The amount of the division needs to account for the VLA size for
1349 CGF.ErrorUnsupported(Ops.E, "VLA pointer subtraction");
1352 const QualType LHSType = Ops.E->getLHS()->getType();
1353 const QualType LHSElementType = LHSType->getPointeeType();
1354 if (!isa<llvm::PointerType>(Ops.RHS->getType())) {
1356 Value *Idx = Ops.RHS;
1357 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth();
1358 if (Width < CGF.LLVMPointerWidth) {
1359 // Zero or sign extend the pointer value based on whether the index is
1361 const llvm::Type *IdxType =
1362 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth);
1363 if (Ops.E->getRHS()->getType()->isSignedIntegerType())
1364 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext");
1366 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext");
1368 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg");
1370 // Handle interface types, which are not represented with a concrete type.
1371 if (const ObjCInterfaceType *OIT =
1372 dyn_cast<ObjCInterfaceType>(LHSElementType)) {
1373 llvm::Value *InterfaceSize =
1374 llvm::ConstantInt::get(Idx->getType(),
1376 getTypeSizeInChars(OIT).getQuantity());
1377 Idx = Builder.CreateMul(Idx, InterfaceSize);
1378 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext);
1379 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty);
1380 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr");
1381 return Builder.CreateBitCast(Res, Ops.LHS->getType());
1384 // Explicitly handle GNU void* and function pointer arithmetic
1385 // extensions. The GNU void* casts amount to no-ops since our void* type is
1386 // i8*, but this is future proof.
1387 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) {
1388 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext);
1389 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty);
1390 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr");
1391 return Builder.CreateBitCast(Res, Ops.LHS->getType());
1394 return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr");
1396 // pointer - pointer
1397 Value *LHS = Ops.LHS;
1398 Value *RHS = Ops.RHS;
1400 CharUnits ElementSize;
1402 // Handle GCC extension for pointer arithmetic on void* and function pointer
1404 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) {
1405 ElementSize = CharUnits::One();
1407 ElementSize = CGF.getContext().getTypeSizeInChars(LHSElementType);
1410 const llvm::Type *ResultType = ConvertType(Ops.Ty);
1411 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast");
1412 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
1413 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub");
1415 // Optimize out the shift for element size of 1.
1416 if (ElementSize.isOne())
1417 return BytesBetween;
1419 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since
1420 // pointer difference in C is only defined in the case where both operands
1421 // are pointing to elements of an array.
1422 Value *BytesPerElt =
1423 llvm::ConstantInt::get(ResultType, ElementSize.getQuantity());
1424 return Builder.CreateExactSDiv(BytesBetween, BytesPerElt, "sub.ptr.div");
1428 Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) {
1429 // LLVM requires the LHS and RHS to be the same type: promote or truncate the
1430 // RHS to the same size as the LHS.
1431 Value *RHS = Ops.RHS;
1432 if (Ops.LHS->getType() != RHS->getType())
1433 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom");
1435 if (CGF.CatchUndefined
1436 && isa<llvm::IntegerType>(Ops.LHS->getType())) {
1437 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth();
1438 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont");
1439 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS,
1440 llvm::ConstantInt::get(RHS->getType(), Width)),
1441 Cont, CGF.getTrapBB());
1442 CGF.EmitBlock(Cont);
1445 return Builder.CreateShl(Ops.LHS, RHS, "shl");
1448 Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) {
1449 // LLVM requires the LHS and RHS to be the same type: promote or truncate the
1450 // RHS to the same size as the LHS.
1451 Value *RHS = Ops.RHS;
1452 if (Ops.LHS->getType() != RHS->getType())
1453 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom");
1455 if (CGF.CatchUndefined
1456 && isa<llvm::IntegerType>(Ops.LHS->getType())) {
1457 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth();
1458 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont");
1459 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS,
1460 llvm::ConstantInt::get(RHS->getType(), Width)),
1461 Cont, CGF.getTrapBB());
1462 CGF.EmitBlock(Cont);
1465 if (Ops.Ty->isUnsignedIntegerType())
1466 return Builder.CreateLShr(Ops.LHS, RHS, "shr");
1467 return Builder.CreateAShr(Ops.LHS, RHS, "shr");
1470 Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc,
1471 unsigned SICmpOpc, unsigned FCmpOpc) {
1472 TestAndClearIgnoreResultAssign();
1474 QualType LHSTy = E->getLHS()->getType();
1475 if (LHSTy->isMemberFunctionPointerType()) {
1476 Value *LHSPtr = CGF.EmitAnyExprToTemp(E->getLHS()).getAggregateAddr();
1477 Value *RHSPtr = CGF.EmitAnyExprToTemp(E->getRHS()).getAggregateAddr();
1478 llvm::Value *LHSFunc = Builder.CreateStructGEP(LHSPtr, 0);
1479 LHSFunc = Builder.CreateLoad(LHSFunc);
1480 llvm::Value *RHSFunc = Builder.CreateStructGEP(RHSPtr, 0);
1481 RHSFunc = Builder.CreateLoad(RHSFunc);
1482 Value *ResultF = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
1483 LHSFunc, RHSFunc, "cmp.func");
1484 Value *NullPtr = llvm::Constant::getNullValue(LHSFunc->getType());
1485 Value *ResultNull = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
1486 LHSFunc, NullPtr, "cmp.null");
1487 llvm::Value *LHSAdj = Builder.CreateStructGEP(LHSPtr, 1);
1488 LHSAdj = Builder.CreateLoad(LHSAdj);
1489 llvm::Value *RHSAdj = Builder.CreateStructGEP(RHSPtr, 1);
1490 RHSAdj = Builder.CreateLoad(RHSAdj);
1491 Value *ResultA = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
1492 LHSAdj, RHSAdj, "cmp.adj");
1493 if (E->getOpcode() == BinaryOperator::EQ) {
1494 Result = Builder.CreateOr(ResultNull, ResultA, "or.na");
1495 Result = Builder.CreateAnd(Result, ResultF, "and.f");
1497 assert(E->getOpcode() == BinaryOperator::NE &&
1498 "Member pointer comparison other than == or != ?");
1499 Result = Builder.CreateAnd(ResultNull, ResultA, "and.na");
1500 Result = Builder.CreateOr(Result, ResultF, "or.f");
1502 } else if (!LHSTy->isAnyComplexType()) {
1503 Value *LHS = Visit(E->getLHS());
1504 Value *RHS = Visit(E->getRHS());
1506 if (LHS->getType()->isFPOrFPVectorTy()) {
1507 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc,
1509 } else if (LHSTy->isSignedIntegerType()) {
1510 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc,
1513 // Unsigned integers and pointers.
1514 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
1518 // If this is a vector comparison, sign extend the result to the appropriate
1519 // vector integer type and return it (don't convert to bool).
1520 if (LHSTy->isVectorType())
1521 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext");
1524 // Complex Comparison: can only be an equality comparison.
1525 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS());
1526 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS());
1528 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType();
1530 Value *ResultR, *ResultI;
1531 if (CETy->isRealFloatingType()) {
1532 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc,
1533 LHS.first, RHS.first, "cmp.r");
1534 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc,
1535 LHS.second, RHS.second, "cmp.i");
1537 // Complex comparisons can only be equality comparisons. As such, signed
1538 // and unsigned opcodes are the same.
1539 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
1540 LHS.first, RHS.first, "cmp.r");
1541 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc,
1542 LHS.second, RHS.second, "cmp.i");
1545 if (E->getOpcode() == BinaryOperator::EQ) {
1546 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri");
1548 assert(E->getOpcode() == BinaryOperator::NE &&
1549 "Complex comparison other than == or != ?");
1550 Result = Builder.CreateOr(ResultR, ResultI, "or.ri");
1554 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType());
1557 Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) {
1558 bool Ignore = TestAndClearIgnoreResultAssign();
1560 // __block variables need to have the rhs evaluated first, plus this should
1561 // improve codegen just a little.
1562 Value *RHS = Visit(E->getRHS());
1563 LValue LHS = EmitCheckedLValue(E->getLHS());
1565 // Store the value into the LHS. Bit-fields are handled specially
1566 // because the result is altered by the store, i.e., [C99 6.5.16p1]
1567 // 'An assignment expression has the value of the left operand after
1568 // the assignment...'.
1569 if (LHS.isBitfield()) {
1570 if (!LHS.isVolatileQualified()) {
1571 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(),
1575 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType());
1577 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType());
1580 return EmitLoadOfLValue(LHS, E->getType());
1583 Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) {
1584 const llvm::Type *ResTy = ConvertType(E->getType());
1586 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0.
1587 // If we have 1 && X, just emit X without inserting the control flow.
1588 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) {
1589 if (Cond == 1) { // If we have 1 && X, just emit X.
1590 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
1591 // ZExt result to int or bool.
1592 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext");
1595 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false.
1596 if (!CGF.ContainsLabel(E->getRHS()))
1597 return llvm::Constant::getNullValue(ResTy);
1600 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end");
1601 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs");
1603 // Branch on the LHS first. If it is false, go to the failure (cont) block.
1604 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock);
1606 // Any edges into the ContBlock are now from an (indeterminate number of)
1607 // edges from this first condition. All of these values will be false. Start
1608 // setting up the PHI node in the Cont Block for this.
1609 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext),
1611 PN->reserveOperandSpace(2); // Normal case, two inputs.
1612 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock);
1614 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI);
1616 CGF.BeginConditionalBranch();
1617 CGF.EmitBlock(RHSBlock);
1618 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
1619 CGF.EndConditionalBranch();
1621 // Reaquire the RHS block, as there may be subblocks inserted.
1622 RHSBlock = Builder.GetInsertBlock();
1624 // Emit an unconditional branch from this block to ContBlock. Insert an entry
1625 // into the phi node for the edge with the value of RHSCond.
1626 CGF.EmitBlock(ContBlock);
1627 PN->addIncoming(RHSCond, RHSBlock);
1629 // ZExt result to int.
1630 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext");
1633 Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) {
1634 const llvm::Type *ResTy = ConvertType(E->getType());
1636 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1.
1637 // If we have 0 || X, just emit X without inserting the control flow.
1638 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) {
1639 if (Cond == -1) { // If we have 0 || X, just emit X.
1640 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
1641 // ZExt result to int or bool.
1642 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext");
1645 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true.
1646 if (!CGF.ContainsLabel(E->getRHS()))
1647 return llvm::ConstantInt::get(ResTy, 1);
1650 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end");
1651 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs");
1653 // Branch on the LHS first. If it is true, go to the success (cont) block.
1654 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock);
1656 // Any edges into the ContBlock are now from an (indeterminate number of)
1657 // edges from this first condition. All of these values will be true. Start
1658 // setting up the PHI node in the Cont Block for this.
1659 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext),
1661 PN->reserveOperandSpace(2); // Normal case, two inputs.
1662 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock);
1664 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI);
1666 CGF.BeginConditionalBranch();
1668 // Emit the RHS condition as a bool value.
1669 CGF.EmitBlock(RHSBlock);
1670 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
1672 CGF.EndConditionalBranch();
1674 // Reaquire the RHS block, as there may be subblocks inserted.
1675 RHSBlock = Builder.GetInsertBlock();
1677 // Emit an unconditional branch from this block to ContBlock. Insert an entry
1678 // into the phi node for the edge with the value of RHSCond.
1679 CGF.EmitBlock(ContBlock);
1680 PN->addIncoming(RHSCond, RHSBlock);
1682 // ZExt result to int.
1683 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext");
1686 Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) {
1687 CGF.EmitStmt(E->getLHS());
1688 CGF.EnsureInsertPoint();
1689 return Visit(E->getRHS());
1692 //===----------------------------------------------------------------------===//
1694 //===----------------------------------------------------------------------===//
1696 /// isCheapEnoughToEvaluateUnconditionally - Return true if the specified
1697 /// expression is cheap enough and side-effect-free enough to evaluate
1698 /// unconditionally instead of conditionally. This is used to convert control
1699 /// flow into selects in some cases.
1700 static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E,
1701 CodeGenFunction &CGF) {
1702 if (const ParenExpr *PE = dyn_cast<ParenExpr>(E))
1703 return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr(), CGF);
1705 // TODO: Allow anything we can constant fold to an integer or fp constant.
1706 if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) ||
1707 isa<FloatingLiteral>(E))
1710 // Non-volatile automatic variables too, to get "cond ? X : Y" where
1711 // X and Y are local variables.
1712 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
1713 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl()))
1714 if (VD->hasLocalStorage() && !(CGF.getContext()
1715 .getCanonicalType(VD->getType())
1716 .isVolatileQualified()))
1723 Value *ScalarExprEmitter::
1724 VisitConditionalOperator(const ConditionalOperator *E) {
1725 TestAndClearIgnoreResultAssign();
1726 // If the condition constant folds and can be elided, try to avoid emitting
1727 // the condition and the dead arm.
1728 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){
1729 Expr *Live = E->getLHS(), *Dead = E->getRHS();
1731 std::swap(Live, Dead);
1733 // If the dead side doesn't have labels we need, and if the Live side isn't
1734 // the gnu missing ?: extension (which we could handle, but don't bother
1735 // to), just emit the Live part.
1736 if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part
1737 Live) // Live part isn't missing.
1742 // If this is a really simple expression (like x ? 4 : 5), emit this as a
1743 // select instead of as control flow. We can only do this if it is cheap and
1744 // safe to evaluate the LHS and RHS unconditionally.
1745 if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS(),
1747 isCheapEnoughToEvaluateUnconditionally(E->getRHS(), CGF)) {
1748 llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond());
1749 llvm::Value *LHS = Visit(E->getLHS());
1750 llvm::Value *RHS = Visit(E->getRHS());
1751 return Builder.CreateSelect(CondV, LHS, RHS, "cond");
1755 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
1756 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
1757 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
1760 // If we don't have the GNU missing condition extension, emit a branch on bool
1763 // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for
1764 // the branch on bool.
1765 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
1767 // Otherwise, for the ?: extension, evaluate the conditional and then
1768 // convert it to bool the hard way. We do this explicitly because we need
1769 // the unconverted value for the missing middle value of the ?:.
1770 CondVal = CGF.EmitScalarExpr(E->getCond());
1772 // In some cases, EmitScalarConversion will delete the "CondVal" expression
1773 // if there are no extra uses (an optimization). Inhibit this by making an
1774 // extra dead use, because we're going to add a use of CondVal later. We
1775 // don't use the builder for this, because we don't want it to get optimized
1776 // away. This leaves dead code, but the ?: extension isn't common.
1777 new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder",
1778 Builder.GetInsertBlock());
1780 Value *CondBoolVal =
1781 CGF.EmitScalarConversion(CondVal, E->getCond()->getType(),
1782 CGF.getContext().BoolTy);
1783 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock);
1786 CGF.BeginConditionalBranch();
1787 CGF.EmitBlock(LHSBlock);
1789 // Handle the GNU extension for missing LHS.
1792 LHS = Visit(E->getLHS());
1793 else // Perform promotions, to handle cases like "short ?: int"
1794 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType());
1796 CGF.EndConditionalBranch();
1797 LHSBlock = Builder.GetInsertBlock();
1798 CGF.EmitBranch(ContBlock);
1800 CGF.BeginConditionalBranch();
1801 CGF.EmitBlock(RHSBlock);
1803 Value *RHS = Visit(E->getRHS());
1804 CGF.EndConditionalBranch();
1805 RHSBlock = Builder.GetInsertBlock();
1806 CGF.EmitBranch(ContBlock);
1808 CGF.EmitBlock(ContBlock);
1810 // If the LHS or RHS is a throw expression, it will be legitimately null.
1816 // Create a PHI node for the real part.
1817 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond");
1818 PN->reserveOperandSpace(2);
1819 PN->addIncoming(LHS, LHSBlock);
1820 PN->addIncoming(RHS, RHSBlock);
1824 Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) {
1825 return Visit(E->getChosenSubExpr(CGF.getContext()));
1828 Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) {
1829 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr());
1830 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType());
1832 // If EmitVAArg fails, we fall back to the LLVM instruction.
1834 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType()));
1836 // FIXME Volatility.
1837 return Builder.CreateLoad(ArgPtr);
1840 Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) {
1841 return CGF.BuildBlockLiteralTmp(BE);
1844 //===----------------------------------------------------------------------===//
1845 // Entry Point into this File
1846 //===----------------------------------------------------------------------===//
1848 /// EmitScalarExpr - Emit the computation of the specified expression of scalar
1849 /// type, ignoring the result.
1850 Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) {
1851 assert(E && !hasAggregateLLVMType(E->getType()) &&
1852 "Invalid scalar expression to emit");
1854 return ScalarExprEmitter(*this, IgnoreResultAssign)
1855 .Visit(const_cast<Expr*>(E));
1858 /// EmitScalarConversion - Emit a conversion from the specified type to the
1859 /// specified destination type, both of which are LLVM scalar types.
1860 Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy,
1862 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) &&
1863 "Invalid scalar expression to emit");
1864 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy);
1867 /// EmitComplexToScalarConversion - Emit a conversion from the specified complex
1868 /// type to the specified destination type, where the destination type is an
1869 /// LLVM scalar type.
1870 Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src,
1873 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) &&
1874 "Invalid complex -> scalar conversion");
1875 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy,
1879 LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) {
1881 // object->isa or (*object).isa
1882 // Generate code as for: *(Class*)object
1883 // build Class* type
1884 const llvm::Type *ClassPtrTy = ConvertType(E->getType());
1886 Expr *BaseExpr = E->getBase();
1887 if (BaseExpr->isLvalue(getContext()) != Expr::LV_Valid) {
1888 V = CreateTempAlloca(ClassPtrTy, "resval");
1889 llvm::Value *Src = EmitScalarExpr(BaseExpr);
1890 Builder.CreateStore(Src, V);
1894 V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr);
1896 V = EmitLValue(BaseExpr).getAddress();
1899 // build Class* type
1900 ClassPtrTy = ClassPtrTy->getPointerTo();
1901 V = Builder.CreateBitCast(V, ClassPtrTy);
1902 LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType()));