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 "CGCleanup.h"
17 #include "CGDebugInfo.h"
18 #include "CGObjCRuntime.h"
19 #include "CodeGenModule.h"
20 #include "TargetInfo.h"
21 #include "clang/AST/ASTContext.h"
22 #include "clang/AST/DeclObjC.h"
23 #include "clang/AST/Expr.h"
24 #include "clang/AST/RecordLayout.h"
25 #include "clang/AST/StmtVisitor.h"
26 #include "clang/Basic/TargetInfo.h"
27 #include "clang/Frontend/CodeGenOptions.h"
28 #include "llvm/ADT/Optional.h"
29 #include "llvm/IR/CFG.h"
30 #include "llvm/IR/Constants.h"
31 #include "llvm/IR/DataLayout.h"
32 #include "llvm/IR/Function.h"
33 #include "llvm/IR/GetElementPtrTypeIterator.h"
34 #include "llvm/IR/GlobalVariable.h"
35 #include "llvm/IR/Intrinsics.h"
36 #include "llvm/IR/Module.h"
39 using namespace clang;
40 using namespace CodeGen;
43 //===----------------------------------------------------------------------===//
44 // Scalar Expression Emitter
45 //===----------------------------------------------------------------------===//
49 /// Determine whether the given binary operation may overflow.
50 /// Sets \p Result to the value of the operation for BO_Add, BO_Sub, BO_Mul,
51 /// and signed BO_{Div,Rem}. For these opcodes, and for unsigned BO_{Div,Rem},
52 /// the returned overflow check is precise. The returned value is 'true' for
53 /// all other opcodes, to be conservative.
54 bool mayHaveIntegerOverflow(llvm::ConstantInt *LHS, llvm::ConstantInt *RHS,
55 BinaryOperator::Opcode Opcode, bool Signed,
56 llvm::APInt &Result) {
57 // Assume overflow is possible, unless we can prove otherwise.
59 const auto &LHSAP = LHS->getValue();
60 const auto &RHSAP = RHS->getValue();
61 if (Opcode == BO_Add) {
63 Result = LHSAP.sadd_ov(RHSAP, Overflow);
65 Result = LHSAP.uadd_ov(RHSAP, Overflow);
66 } else if (Opcode == BO_Sub) {
68 Result = LHSAP.ssub_ov(RHSAP, Overflow);
70 Result = LHSAP.usub_ov(RHSAP, Overflow);
71 } else if (Opcode == BO_Mul) {
73 Result = LHSAP.smul_ov(RHSAP, Overflow);
75 Result = LHSAP.umul_ov(RHSAP, Overflow);
76 } else if (Opcode == BO_Div || Opcode == BO_Rem) {
77 if (Signed && !RHS->isZero())
78 Result = LHSAP.sdiv_ov(RHSAP, Overflow);
88 QualType Ty; // Computation Type.
89 BinaryOperator::Opcode Opcode; // Opcode of BinOp to perform
91 const Expr *E; // Entire expr, for error unsupported. May not be binop.
93 /// Check if the binop can result in integer overflow.
94 bool mayHaveIntegerOverflow() const {
95 // Without constant input, we can't rule out overflow.
96 auto *LHSCI = dyn_cast<llvm::ConstantInt>(LHS);
97 auto *RHSCI = dyn_cast<llvm::ConstantInt>(RHS);
102 return ::mayHaveIntegerOverflow(
103 LHSCI, RHSCI, Opcode, Ty->hasSignedIntegerRepresentation(), Result);
106 /// Check if the binop computes a division or a remainder.
107 bool isDivremOp() const {
108 return Opcode == BO_Div || Opcode == BO_Rem || Opcode == BO_DivAssign ||
109 Opcode == BO_RemAssign;
112 /// Check if the binop can result in an integer division by zero.
113 bool mayHaveIntegerDivisionByZero() const {
115 if (auto *CI = dyn_cast<llvm::ConstantInt>(RHS))
120 /// Check if the binop can result in a float division by zero.
121 bool mayHaveFloatDivisionByZero() const {
123 if (auto *CFP = dyn_cast<llvm::ConstantFP>(RHS))
124 return CFP->isZero();
129 static bool MustVisitNullValue(const Expr *E) {
130 // If a null pointer expression's type is the C++0x nullptr_t, then
131 // it's not necessarily a simple constant and it must be evaluated
132 // for its potential side effects.
133 return E->getType()->isNullPtrType();
136 /// If \p E is a widened promoted integer, get its base (unpromoted) type.
137 static llvm::Optional<QualType> getUnwidenedIntegerType(const ASTContext &Ctx,
139 const Expr *Base = E->IgnoreImpCasts();
143 QualType BaseTy = Base->getType();
144 if (!BaseTy->isPromotableIntegerType() ||
145 Ctx.getTypeSize(BaseTy) >= Ctx.getTypeSize(E->getType()))
151 /// Check if \p E is a widened promoted integer.
152 static bool IsWidenedIntegerOp(const ASTContext &Ctx, const Expr *E) {
153 return getUnwidenedIntegerType(Ctx, E).hasValue();
156 /// Check if we can skip the overflow check for \p Op.
157 static bool CanElideOverflowCheck(const ASTContext &Ctx, const BinOpInfo &Op) {
158 assert((isa<UnaryOperator>(Op.E) || isa<BinaryOperator>(Op.E)) &&
159 "Expected a unary or binary operator");
161 // If the binop has constant inputs and we can prove there is no overflow,
162 // we can elide the overflow check.
163 if (!Op.mayHaveIntegerOverflow())
166 // If a unary op has a widened operand, the op cannot overflow.
167 if (const auto *UO = dyn_cast<UnaryOperator>(Op.E))
168 return IsWidenedIntegerOp(Ctx, UO->getSubExpr());
170 // We usually don't need overflow checks for binops with widened operands.
171 // Multiplication with promoted unsigned operands is a special case.
172 const auto *BO = cast<BinaryOperator>(Op.E);
173 auto OptionalLHSTy = getUnwidenedIntegerType(Ctx, BO->getLHS());
177 auto OptionalRHSTy = getUnwidenedIntegerType(Ctx, BO->getRHS());
181 QualType LHSTy = *OptionalLHSTy;
182 QualType RHSTy = *OptionalRHSTy;
184 // This is the simple case: binops without unsigned multiplication, and with
185 // widened operands. No overflow check is needed here.
186 if ((Op.Opcode != BO_Mul && Op.Opcode != BO_MulAssign) ||
187 !LHSTy->isUnsignedIntegerType() || !RHSTy->isUnsignedIntegerType())
190 // For unsigned multiplication the overflow check can be elided if either one
191 // of the unpromoted types are less than half the size of the promoted type.
192 unsigned PromotedSize = Ctx.getTypeSize(Op.E->getType());
193 return (2 * Ctx.getTypeSize(LHSTy)) < PromotedSize ||
194 (2 * Ctx.getTypeSize(RHSTy)) < PromotedSize;
197 /// Update the FastMathFlags of LLVM IR from the FPOptions in LangOptions.
198 static void updateFastMathFlags(llvm::FastMathFlags &FMF,
199 FPOptions FPFeatures) {
200 FMF.setAllowContract(FPFeatures.allowFPContractAcrossStatement());
203 /// Propagate fast-math flags from \p Op to the instruction in \p V.
204 static Value *propagateFMFlags(Value *V, const BinOpInfo &Op) {
205 if (auto *I = dyn_cast<llvm::Instruction>(V)) {
206 llvm::FastMathFlags FMF = I->getFastMathFlags();
207 updateFastMathFlags(FMF, Op.FPFeatures);
208 I->setFastMathFlags(FMF);
213 class ScalarExprEmitter
214 : public StmtVisitor<ScalarExprEmitter, Value*> {
215 CodeGenFunction &CGF;
216 CGBuilderTy &Builder;
217 bool IgnoreResultAssign;
218 llvm::LLVMContext &VMContext;
221 ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false)
222 : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira),
223 VMContext(cgf.getLLVMContext()) {
226 //===--------------------------------------------------------------------===//
228 //===--------------------------------------------------------------------===//
230 bool TestAndClearIgnoreResultAssign() {
231 bool I = IgnoreResultAssign;
232 IgnoreResultAssign = false;
236 llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); }
237 LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); }
238 LValue EmitCheckedLValue(const Expr *E, CodeGenFunction::TypeCheckKind TCK) {
239 return CGF.EmitCheckedLValue(E, TCK);
242 void EmitBinOpCheck(ArrayRef<std::pair<Value *, SanitizerMask>> Checks,
243 const BinOpInfo &Info);
245 Value *EmitLoadOfLValue(LValue LV, SourceLocation Loc) {
246 return CGF.EmitLoadOfLValue(LV, Loc).getScalarVal();
249 void EmitLValueAlignmentAssumption(const Expr *E, Value *V) {
250 const AlignValueAttr *AVAttr = nullptr;
251 if (const auto *DRE = dyn_cast<DeclRefExpr>(E)) {
252 const ValueDecl *VD = DRE->getDecl();
254 if (VD->getType()->isReferenceType()) {
255 if (const auto *TTy =
256 dyn_cast<TypedefType>(VD->getType().getNonReferenceType()))
257 AVAttr = TTy->getDecl()->getAttr<AlignValueAttr>();
259 // Assumptions for function parameters are emitted at the start of the
260 // function, so there is no need to repeat that here.
261 if (isa<ParmVarDecl>(VD))
264 AVAttr = VD->getAttr<AlignValueAttr>();
269 if (const auto *TTy =
270 dyn_cast<TypedefType>(E->getType()))
271 AVAttr = TTy->getDecl()->getAttr<AlignValueAttr>();
276 Value *AlignmentValue = CGF.EmitScalarExpr(AVAttr->getAlignment());
277 llvm::ConstantInt *AlignmentCI = cast<llvm::ConstantInt>(AlignmentValue);
278 CGF.EmitAlignmentAssumption(V, AlignmentCI->getZExtValue());
281 /// EmitLoadOfLValue - Given an expression with complex type that represents a
282 /// value l-value, this method emits the address of the l-value, then loads
283 /// and returns the result.
284 Value *EmitLoadOfLValue(const Expr *E) {
285 Value *V = EmitLoadOfLValue(EmitCheckedLValue(E, CodeGenFunction::TCK_Load),
288 EmitLValueAlignmentAssumption(E, V);
292 /// EmitConversionToBool - Convert the specified expression value to a
293 /// boolean (i1) truth value. This is equivalent to "Val != 0".
294 Value *EmitConversionToBool(Value *Src, QualType DstTy);
296 /// Emit a check that a conversion to or from a floating-point type does not
298 void EmitFloatConversionCheck(Value *OrigSrc, QualType OrigSrcType,
299 Value *Src, QualType SrcType, QualType DstType,
300 llvm::Type *DstTy, SourceLocation Loc);
302 /// Emit a conversion from the specified type to the specified destination
303 /// type, both of which are LLVM scalar types.
304 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy,
307 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy,
308 SourceLocation Loc, bool TreatBooleanAsSigned);
310 /// Emit a conversion from the specified complex type to the specified
311 /// destination type, where the destination type is an LLVM scalar type.
312 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src,
313 QualType SrcTy, QualType DstTy,
316 /// EmitNullValue - Emit a value that corresponds to null for the given type.
317 Value *EmitNullValue(QualType Ty);
319 /// EmitFloatToBoolConversion - Perform an FP to boolean conversion.
320 Value *EmitFloatToBoolConversion(Value *V) {
321 // Compare against 0.0 for fp scalars.
322 llvm::Value *Zero = llvm::Constant::getNullValue(V->getType());
323 return Builder.CreateFCmpUNE(V, Zero, "tobool");
326 /// EmitPointerToBoolConversion - Perform a pointer to boolean conversion.
327 Value *EmitPointerToBoolConversion(Value *V, QualType QT) {
328 Value *Zero = CGF.CGM.getNullPointer(cast<llvm::PointerType>(V->getType()), QT);
330 return Builder.CreateICmpNE(V, Zero, "tobool");
333 Value *EmitIntToBoolConversion(Value *V) {
334 // Because of the type rules of C, we often end up computing a
335 // logical value, then zero extending it to int, then wanting it
336 // as a logical value again. Optimize this common case.
337 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(V)) {
338 if (ZI->getOperand(0)->getType() == Builder.getInt1Ty()) {
339 Value *Result = ZI->getOperand(0);
340 // If there aren't any more uses, zap the instruction to save space.
341 // Note that there can be more uses, for example if this
342 // is the result of an assignment.
344 ZI->eraseFromParent();
349 return Builder.CreateIsNotNull(V, "tobool");
352 //===--------------------------------------------------------------------===//
354 //===--------------------------------------------------------------------===//
356 Value *Visit(Expr *E) {
357 ApplyDebugLocation DL(CGF, E);
358 return StmtVisitor<ScalarExprEmitter, Value*>::Visit(E);
361 Value *VisitStmt(Stmt *S) {
362 S->dump(CGF.getContext().getSourceManager());
363 llvm_unreachable("Stmt can't have complex result type!");
365 Value *VisitExpr(Expr *S);
367 Value *VisitParenExpr(ParenExpr *PE) {
368 return Visit(PE->getSubExpr());
370 Value *VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) {
371 return Visit(E->getReplacement());
373 Value *VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
374 return Visit(GE->getResultExpr());
376 Value *VisitCoawaitExpr(CoawaitExpr *S) {
377 return CGF.EmitCoawaitExpr(*S).getScalarVal();
379 Value *VisitCoyieldExpr(CoyieldExpr *S) {
380 return CGF.EmitCoyieldExpr(*S).getScalarVal();
382 Value *VisitUnaryCoawait(const UnaryOperator *E) {
383 return Visit(E->getSubExpr());
387 Value *VisitIntegerLiteral(const IntegerLiteral *E) {
388 return Builder.getInt(E->getValue());
390 Value *VisitFloatingLiteral(const FloatingLiteral *E) {
391 return llvm::ConstantFP::get(VMContext, E->getValue());
393 Value *VisitCharacterLiteral(const CharacterLiteral *E) {
394 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
396 Value *VisitObjCBoolLiteralExpr(const ObjCBoolLiteralExpr *E) {
397 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
399 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) {
400 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
402 Value *VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) {
403 return EmitNullValue(E->getType());
405 Value *VisitGNUNullExpr(const GNUNullExpr *E) {
406 return EmitNullValue(E->getType());
408 Value *VisitOffsetOfExpr(OffsetOfExpr *E);
409 Value *VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E);
410 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) {
411 llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel());
412 return Builder.CreateBitCast(V, ConvertType(E->getType()));
415 Value *VisitSizeOfPackExpr(SizeOfPackExpr *E) {
416 return llvm::ConstantInt::get(ConvertType(E->getType()),E->getPackLength());
419 Value *VisitPseudoObjectExpr(PseudoObjectExpr *E) {
420 return CGF.EmitPseudoObjectRValue(E).getScalarVal();
423 Value *VisitOpaqueValueExpr(OpaqueValueExpr *E) {
425 return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E), E->getExprLoc());
427 // Otherwise, assume the mapping is the scalar directly.
428 return CGF.getOpaqueRValueMapping(E).getScalarVal();
431 Value *emitConstant(const CodeGenFunction::ConstantEmission &Constant,
433 assert(Constant && "not a constant");
434 if (Constant.isReference())
435 return EmitLoadOfLValue(Constant.getReferenceLValue(CGF, E),
437 return Constant.getValue();
441 Value *VisitDeclRefExpr(DeclRefExpr *E) {
442 if (CodeGenFunction::ConstantEmission Constant = CGF.tryEmitAsConstant(E))
443 return emitConstant(Constant, E);
444 return EmitLoadOfLValue(E);
447 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) {
448 return CGF.EmitObjCSelectorExpr(E);
450 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) {
451 return CGF.EmitObjCProtocolExpr(E);
453 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
454 return EmitLoadOfLValue(E);
456 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) {
457 if (E->getMethodDecl() &&
458 E->getMethodDecl()->getReturnType()->isReferenceType())
459 return EmitLoadOfLValue(E);
460 return CGF.EmitObjCMessageExpr(E).getScalarVal();
463 Value *VisitObjCIsaExpr(ObjCIsaExpr *E) {
464 LValue LV = CGF.EmitObjCIsaExpr(E);
465 Value *V = CGF.EmitLoadOfLValue(LV, E->getExprLoc()).getScalarVal();
469 Value *VisitObjCAvailabilityCheckExpr(ObjCAvailabilityCheckExpr *E) {
470 VersionTuple Version = E->getVersion();
472 // If we're checking for a platform older than our minimum deployment
473 // target, we can fold the check away.
474 if (Version <= CGF.CGM.getTarget().getPlatformMinVersion())
475 return llvm::ConstantInt::get(Builder.getInt1Ty(), 1);
477 Optional<unsigned> Min = Version.getMinor(), SMin = Version.getSubminor();
478 llvm::Value *Args[] = {
479 llvm::ConstantInt::get(CGF.CGM.Int32Ty, Version.getMajor()),
480 llvm::ConstantInt::get(CGF.CGM.Int32Ty, Min ? *Min : 0),
481 llvm::ConstantInt::get(CGF.CGM.Int32Ty, SMin ? *SMin : 0),
484 return CGF.EmitBuiltinAvailable(Args);
487 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E);
488 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E);
489 Value *VisitConvertVectorExpr(ConvertVectorExpr *E);
490 Value *VisitMemberExpr(MemberExpr *E);
491 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); }
492 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
493 return EmitLoadOfLValue(E);
496 Value *VisitInitListExpr(InitListExpr *E);
498 Value *VisitArrayInitIndexExpr(ArrayInitIndexExpr *E) {
499 assert(CGF.getArrayInitIndex() &&
500 "ArrayInitIndexExpr not inside an ArrayInitLoopExpr?");
501 return CGF.getArrayInitIndex();
504 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) {
505 return EmitNullValue(E->getType());
507 Value *VisitExplicitCastExpr(ExplicitCastExpr *E) {
508 CGF.CGM.EmitExplicitCastExprType(E, &CGF);
509 return VisitCastExpr(E);
511 Value *VisitCastExpr(CastExpr *E);
513 Value *VisitCallExpr(const CallExpr *E) {
514 if (E->getCallReturnType(CGF.getContext())->isReferenceType())
515 return EmitLoadOfLValue(E);
517 Value *V = CGF.EmitCallExpr(E).getScalarVal();
519 EmitLValueAlignmentAssumption(E, V);
523 Value *VisitStmtExpr(const StmtExpr *E);
526 Value *VisitUnaryPostDec(const UnaryOperator *E) {
527 LValue LV = EmitLValue(E->getSubExpr());
528 return EmitScalarPrePostIncDec(E, LV, false, false);
530 Value *VisitUnaryPostInc(const UnaryOperator *E) {
531 LValue LV = EmitLValue(E->getSubExpr());
532 return EmitScalarPrePostIncDec(E, LV, true, false);
534 Value *VisitUnaryPreDec(const UnaryOperator *E) {
535 LValue LV = EmitLValue(E->getSubExpr());
536 return EmitScalarPrePostIncDec(E, LV, false, true);
538 Value *VisitUnaryPreInc(const UnaryOperator *E) {
539 LValue LV = EmitLValue(E->getSubExpr());
540 return EmitScalarPrePostIncDec(E, LV, true, true);
543 llvm::Value *EmitIncDecConsiderOverflowBehavior(const UnaryOperator *E,
547 llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
548 bool isInc, bool isPre);
551 Value *VisitUnaryAddrOf(const UnaryOperator *E) {
552 if (isa<MemberPointerType>(E->getType())) // never sugared
553 return CGF.CGM.getMemberPointerConstant(E);
555 return EmitLValue(E->getSubExpr()).getPointer();
557 Value *VisitUnaryDeref(const UnaryOperator *E) {
558 if (E->getType()->isVoidType())
559 return Visit(E->getSubExpr()); // the actual value should be unused
560 return EmitLoadOfLValue(E);
562 Value *VisitUnaryPlus(const UnaryOperator *E) {
563 // This differs from gcc, though, most likely due to a bug in gcc.
564 TestAndClearIgnoreResultAssign();
565 return Visit(E->getSubExpr());
567 Value *VisitUnaryMinus (const UnaryOperator *E);
568 Value *VisitUnaryNot (const UnaryOperator *E);
569 Value *VisitUnaryLNot (const UnaryOperator *E);
570 Value *VisitUnaryReal (const UnaryOperator *E);
571 Value *VisitUnaryImag (const UnaryOperator *E);
572 Value *VisitUnaryExtension(const UnaryOperator *E) {
573 return Visit(E->getSubExpr());
577 Value *VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E) {
578 return EmitLoadOfLValue(E);
581 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
582 return Visit(DAE->getExpr());
584 Value *VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
585 CodeGenFunction::CXXDefaultInitExprScope Scope(CGF);
586 return Visit(DIE->getExpr());
588 Value *VisitCXXThisExpr(CXXThisExpr *TE) {
589 return CGF.LoadCXXThis();
592 Value *VisitExprWithCleanups(ExprWithCleanups *E);
593 Value *VisitCXXNewExpr(const CXXNewExpr *E) {
594 return CGF.EmitCXXNewExpr(E);
596 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) {
597 CGF.EmitCXXDeleteExpr(E);
601 Value *VisitTypeTraitExpr(const TypeTraitExpr *E) {
602 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue());
605 Value *VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) {
606 return llvm::ConstantInt::get(Builder.getInt32Ty(), E->getValue());
609 Value *VisitExpressionTraitExpr(const ExpressionTraitExpr *E) {
610 return llvm::ConstantInt::get(Builder.getInt1Ty(), E->getValue());
613 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) {
614 // C++ [expr.pseudo]p1:
615 // The result shall only be used as the operand for the function call
616 // operator (), and the result of such a call has type void. The only
617 // effect is the evaluation of the postfix-expression before the dot or
619 CGF.EmitScalarExpr(E->getBase());
623 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) {
624 return EmitNullValue(E->getType());
627 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) {
628 CGF.EmitCXXThrowExpr(E);
632 Value *VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) {
633 return Builder.getInt1(E->getValue());
637 Value *EmitMul(const BinOpInfo &Ops) {
638 if (Ops.Ty->isSignedIntegerOrEnumerationType()) {
639 switch (CGF.getLangOpts().getSignedOverflowBehavior()) {
640 case LangOptions::SOB_Defined:
641 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul");
642 case LangOptions::SOB_Undefined:
643 if (!CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow))
644 return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul");
646 case LangOptions::SOB_Trapping:
647 if (CanElideOverflowCheck(CGF.getContext(), Ops))
648 return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul");
649 return EmitOverflowCheckedBinOp(Ops);
653 if (Ops.Ty->isUnsignedIntegerType() &&
654 CGF.SanOpts.has(SanitizerKind::UnsignedIntegerOverflow) &&
655 !CanElideOverflowCheck(CGF.getContext(), Ops))
656 return EmitOverflowCheckedBinOp(Ops);
658 if (Ops.LHS->getType()->isFPOrFPVectorTy()) {
659 Value *V = Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul");
660 return propagateFMFlags(V, Ops);
662 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul");
664 /// Create a binary op that checks for overflow.
665 /// Currently only supports +, - and *.
666 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops);
668 // Check for undefined division and modulus behaviors.
669 void EmitUndefinedBehaviorIntegerDivAndRemCheck(const BinOpInfo &Ops,
670 llvm::Value *Zero,bool isDiv);
671 // Common helper for getting how wide LHS of shift is.
672 static Value *GetWidthMinusOneValue(Value* LHS,Value* RHS);
673 Value *EmitDiv(const BinOpInfo &Ops);
674 Value *EmitRem(const BinOpInfo &Ops);
675 Value *EmitAdd(const BinOpInfo &Ops);
676 Value *EmitSub(const BinOpInfo &Ops);
677 Value *EmitShl(const BinOpInfo &Ops);
678 Value *EmitShr(const BinOpInfo &Ops);
679 Value *EmitAnd(const BinOpInfo &Ops) {
680 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and");
682 Value *EmitXor(const BinOpInfo &Ops) {
683 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor");
685 Value *EmitOr (const BinOpInfo &Ops) {
686 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or");
689 BinOpInfo EmitBinOps(const BinaryOperator *E);
690 LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
691 Value *(ScalarExprEmitter::*F)(const BinOpInfo &),
694 Value *EmitCompoundAssign(const CompoundAssignOperator *E,
695 Value *(ScalarExprEmitter::*F)(const BinOpInfo &));
697 // Binary operators and binary compound assignment operators.
698 #define HANDLEBINOP(OP) \
699 Value *VisitBin ## OP(const BinaryOperator *E) { \
700 return Emit ## OP(EmitBinOps(E)); \
702 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \
703 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \
718 Value *EmitCompare(const BinaryOperator *E, llvm::CmpInst::Predicate UICmpOpc,
719 llvm::CmpInst::Predicate SICmpOpc,
720 llvm::CmpInst::Predicate FCmpOpc);
721 #define VISITCOMP(CODE, UI, SI, FP) \
722 Value *VisitBin##CODE(const BinaryOperator *E) { \
723 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \
724 llvm::FCmpInst::FP); }
725 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT)
726 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT)
727 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE)
728 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE)
729 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ)
730 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE)
733 Value *VisitBinAssign (const BinaryOperator *E);
735 Value *VisitBinLAnd (const BinaryOperator *E);
736 Value *VisitBinLOr (const BinaryOperator *E);
737 Value *VisitBinComma (const BinaryOperator *E);
739 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); }
740 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); }
743 Value *VisitBlockExpr(const BlockExpr *BE);
744 Value *VisitAbstractConditionalOperator(const AbstractConditionalOperator *);
745 Value *VisitChooseExpr(ChooseExpr *CE);
746 Value *VisitVAArgExpr(VAArgExpr *VE);
747 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) {
748 return CGF.EmitObjCStringLiteral(E);
750 Value *VisitObjCBoxedExpr(ObjCBoxedExpr *E) {
751 return CGF.EmitObjCBoxedExpr(E);
753 Value *VisitObjCArrayLiteral(ObjCArrayLiteral *E) {
754 return CGF.EmitObjCArrayLiteral(E);
756 Value *VisitObjCDictionaryLiteral(ObjCDictionaryLiteral *E) {
757 return CGF.EmitObjCDictionaryLiteral(E);
759 Value *VisitAsTypeExpr(AsTypeExpr *CE);
760 Value *VisitAtomicExpr(AtomicExpr *AE);
762 } // end anonymous namespace.
764 //===----------------------------------------------------------------------===//
766 //===----------------------------------------------------------------------===//
768 /// EmitConversionToBool - Convert the specified expression value to a
769 /// boolean (i1) truth value. This is equivalent to "Val != 0".
770 Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) {
771 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs");
773 if (SrcType->isRealFloatingType())
774 return EmitFloatToBoolConversion(Src);
776 if (const MemberPointerType *MPT = dyn_cast<MemberPointerType>(SrcType))
777 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, Src, MPT);
779 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) &&
780 "Unknown scalar type to convert");
782 if (isa<llvm::IntegerType>(Src->getType()))
783 return EmitIntToBoolConversion(Src);
785 assert(isa<llvm::PointerType>(Src->getType()));
786 return EmitPointerToBoolConversion(Src, SrcType);
789 void ScalarExprEmitter::EmitFloatConversionCheck(
790 Value *OrigSrc, QualType OrigSrcType, Value *Src, QualType SrcType,
791 QualType DstType, llvm::Type *DstTy, SourceLocation Loc) {
792 CodeGenFunction::SanitizerScope SanScope(&CGF);
796 llvm::Type *SrcTy = Src->getType();
798 llvm::Value *Check = nullptr;
799 if (llvm::IntegerType *IntTy = dyn_cast<llvm::IntegerType>(SrcTy)) {
800 // Integer to floating-point. This can fail for unsigned short -> __half
801 // or unsigned __int128 -> float.
802 assert(DstType->isFloatingType());
803 bool SrcIsUnsigned = OrigSrcType->isUnsignedIntegerOrEnumerationType();
805 APFloat LargestFloat =
806 APFloat::getLargest(CGF.getContext().getFloatTypeSemantics(DstType));
807 APSInt LargestInt(IntTy->getBitWidth(), SrcIsUnsigned);
810 if (LargestFloat.convertToInteger(LargestInt, APFloat::rmTowardZero,
811 &IsExact) != APFloat::opOK)
812 // The range of representable values of this floating point type includes
813 // all values of this integer type. Don't need an overflow check.
816 llvm::Value *Max = llvm::ConstantInt::get(VMContext, LargestInt);
818 Check = Builder.CreateICmpULE(Src, Max);
820 llvm::Value *Min = llvm::ConstantInt::get(VMContext, -LargestInt);
821 llvm::Value *GE = Builder.CreateICmpSGE(Src, Min);
822 llvm::Value *LE = Builder.CreateICmpSLE(Src, Max);
823 Check = Builder.CreateAnd(GE, LE);
826 const llvm::fltSemantics &SrcSema =
827 CGF.getContext().getFloatTypeSemantics(OrigSrcType);
828 if (isa<llvm::IntegerType>(DstTy)) {
829 // Floating-point to integer. This has undefined behavior if the source is
830 // +-Inf, NaN, or doesn't fit into the destination type (after truncation
832 unsigned Width = CGF.getContext().getIntWidth(DstType);
833 bool Unsigned = DstType->isUnsignedIntegerOrEnumerationType();
835 APSInt Min = APSInt::getMinValue(Width, Unsigned);
836 APFloat MinSrc(SrcSema, APFloat::uninitialized);
837 if (MinSrc.convertFromAPInt(Min, !Unsigned, APFloat::rmTowardZero) &
839 // Don't need an overflow check for lower bound. Just check for
841 MinSrc = APFloat::getInf(SrcSema, true);
843 // Find the largest value which is too small to represent (before
844 // truncation toward zero).
845 MinSrc.subtract(APFloat(SrcSema, 1), APFloat::rmTowardNegative);
847 APSInt Max = APSInt::getMaxValue(Width, Unsigned);
848 APFloat MaxSrc(SrcSema, APFloat::uninitialized);
849 if (MaxSrc.convertFromAPInt(Max, !Unsigned, APFloat::rmTowardZero) &
851 // Don't need an overflow check for upper bound. Just check for
853 MaxSrc = APFloat::getInf(SrcSema, false);
855 // Find the smallest value which is too large to represent (before
856 // truncation toward zero).
857 MaxSrc.add(APFloat(SrcSema, 1), APFloat::rmTowardPositive);
859 // If we're converting from __half, convert the range to float to match
861 if (OrigSrcType->isHalfType()) {
862 const llvm::fltSemantics &Sema =
863 CGF.getContext().getFloatTypeSemantics(SrcType);
865 MinSrc.convert(Sema, APFloat::rmTowardZero, &IsInexact);
866 MaxSrc.convert(Sema, APFloat::rmTowardZero, &IsInexact);
870 Builder.CreateFCmpOGT(Src, llvm::ConstantFP::get(VMContext, MinSrc));
872 Builder.CreateFCmpOLT(Src, llvm::ConstantFP::get(VMContext, MaxSrc));
873 Check = Builder.CreateAnd(GE, LE);
875 // FIXME: Maybe split this sanitizer out from float-cast-overflow.
877 // Floating-point to floating-point. This has undefined behavior if the
878 // source is not in the range of representable values of the destination
879 // type. The C and C++ standards are spectacularly unclear here. We
880 // diagnose finite out-of-range conversions, but allow infinities and NaNs
881 // to convert to the corresponding value in the smaller type.
883 // C11 Annex F gives all such conversions defined behavior for IEC 60559
884 // conforming implementations. Unfortunately, LLVM's fptrunc instruction
887 // Converting from a lower rank to a higher rank can never have
888 // undefined behavior, since higher-rank types must have a superset
889 // of values of lower-rank types.
890 if (CGF.getContext().getFloatingTypeOrder(OrigSrcType, DstType) != 1)
893 assert(!OrigSrcType->isHalfType() &&
894 "should not check conversion from __half, it has the lowest rank");
896 const llvm::fltSemantics &DstSema =
897 CGF.getContext().getFloatTypeSemantics(DstType);
898 APFloat MinBad = APFloat::getLargest(DstSema, false);
899 APFloat MaxBad = APFloat::getInf(DstSema, false);
902 MinBad.convert(SrcSema, APFloat::rmTowardZero, &IsInexact);
903 MaxBad.convert(SrcSema, APFloat::rmTowardZero, &IsInexact);
905 Value *AbsSrc = CGF.EmitNounwindRuntimeCall(
906 CGF.CGM.getIntrinsic(llvm::Intrinsic::fabs, Src->getType()), Src);
908 Builder.CreateFCmpOGT(AbsSrc, llvm::ConstantFP::get(VMContext, MinBad));
910 Builder.CreateFCmpOLT(AbsSrc, llvm::ConstantFP::get(VMContext, MaxBad));
911 Check = Builder.CreateNot(Builder.CreateAnd(GE, LE));
915 llvm::Constant *StaticArgs[] = {CGF.EmitCheckSourceLocation(Loc),
916 CGF.EmitCheckTypeDescriptor(OrigSrcType),
917 CGF.EmitCheckTypeDescriptor(DstType)};
918 CGF.EmitCheck(std::make_pair(Check, SanitizerKind::FloatCastOverflow),
919 SanitizerHandler::FloatCastOverflow, StaticArgs, OrigSrc);
922 /// Emit a conversion from the specified type to the specified destination type,
923 /// both of which are LLVM scalar types.
924 Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType,
926 SourceLocation Loc) {
927 return EmitScalarConversion(Src, SrcType, DstType, Loc, false);
930 Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType,
933 bool TreatBooleanAsSigned) {
934 SrcType = CGF.getContext().getCanonicalType(SrcType);
935 DstType = CGF.getContext().getCanonicalType(DstType);
936 if (SrcType == DstType) return Src;
938 if (DstType->isVoidType()) return nullptr;
940 llvm::Value *OrigSrc = Src;
941 QualType OrigSrcType = SrcType;
942 llvm::Type *SrcTy = Src->getType();
944 // Handle conversions to bool first, they are special: comparisons against 0.
945 if (DstType->isBooleanType())
946 return EmitConversionToBool(Src, SrcType);
948 llvm::Type *DstTy = ConvertType(DstType);
950 // Cast from half through float if half isn't a native type.
951 if (SrcType->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) {
952 // Cast to FP using the intrinsic if the half type itself isn't supported.
953 if (DstTy->isFloatingPointTy()) {
954 if (CGF.getContext().getTargetInfo().useFP16ConversionIntrinsics())
955 return Builder.CreateCall(
956 CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16, DstTy),
959 // Cast to other types through float, using either the intrinsic or FPExt,
960 // depending on whether the half type itself is supported
961 // (as opposed to operations on half, available with NativeHalfType).
962 if (CGF.getContext().getTargetInfo().useFP16ConversionIntrinsics()) {
963 Src = Builder.CreateCall(
964 CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16,
968 Src = Builder.CreateFPExt(Src, CGF.CGM.FloatTy, "conv");
970 SrcType = CGF.getContext().FloatTy;
975 // Ignore conversions like int -> uint.
979 // Handle pointer conversions next: pointers can only be converted to/from
980 // other pointers and integers. Check for pointer types in terms of LLVM, as
981 // some native types (like Obj-C id) may map to a pointer type.
982 if (auto DstPT = dyn_cast<llvm::PointerType>(DstTy)) {
983 // The source value may be an integer, or a pointer.
984 if (isa<llvm::PointerType>(SrcTy))
985 return Builder.CreateBitCast(Src, DstTy, "conv");
987 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?");
988 // First, convert to the correct width so that we control the kind of
990 llvm::Type *MiddleTy = CGF.CGM.getDataLayout().getIntPtrType(DstPT);
991 bool InputSigned = SrcType->isSignedIntegerOrEnumerationType();
992 llvm::Value* IntResult =
993 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv");
994 // Then, cast to pointer.
995 return Builder.CreateIntToPtr(IntResult, DstTy, "conv");
998 if (isa<llvm::PointerType>(SrcTy)) {
999 // Must be an ptr to int cast.
1000 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?");
1001 return Builder.CreatePtrToInt(Src, DstTy, "conv");
1004 // A scalar can be splatted to an extended vector of the same element type
1005 if (DstType->isExtVectorType() && !SrcType->isVectorType()) {
1006 // Sema should add casts to make sure that the source expression's type is
1007 // the same as the vector's element type (sans qualifiers)
1008 assert(DstType->castAs<ExtVectorType>()->getElementType().getTypePtr() ==
1009 SrcType.getTypePtr() &&
1010 "Splatted expr doesn't match with vector element type?");
1012 // Splat the element across to all elements
1013 unsigned NumElements = DstTy->getVectorNumElements();
1014 return Builder.CreateVectorSplat(NumElements, Src, "splat");
1017 if (isa<llvm::VectorType>(SrcTy) || isa<llvm::VectorType>(DstTy)) {
1018 // Allow bitcast from vector to integer/fp of the same size.
1019 unsigned SrcSize = SrcTy->getPrimitiveSizeInBits();
1020 unsigned DstSize = DstTy->getPrimitiveSizeInBits();
1021 if (SrcSize == DstSize)
1022 return Builder.CreateBitCast(Src, DstTy, "conv");
1024 // Conversions between vectors of different sizes are not allowed except
1025 // when vectors of half are involved. Operations on storage-only half
1026 // vectors require promoting half vector operands to float vectors and
1027 // truncating the result, which is either an int or float vector, to a
1028 // short or half vector.
1030 // Source and destination are both expected to be vectors.
1031 llvm::Type *SrcElementTy = SrcTy->getVectorElementType();
1032 llvm::Type *DstElementTy = DstTy->getVectorElementType();
1035 assert(((SrcElementTy->isIntegerTy() &&
1036 DstElementTy->isIntegerTy()) ||
1037 (SrcElementTy->isFloatingPointTy() &&
1038 DstElementTy->isFloatingPointTy())) &&
1039 "unexpected conversion between a floating-point vector and an "
1042 // Truncate an i32 vector to an i16 vector.
1043 if (SrcElementTy->isIntegerTy())
1044 return Builder.CreateIntCast(Src, DstTy, false, "conv");
1046 // Truncate a float vector to a half vector.
1047 if (SrcSize > DstSize)
1048 return Builder.CreateFPTrunc(Src, DstTy, "conv");
1050 // Promote a half vector to a float vector.
1051 return Builder.CreateFPExt(Src, DstTy, "conv");
1054 // Finally, we have the arithmetic types: real int/float.
1055 Value *Res = nullptr;
1056 llvm::Type *ResTy = DstTy;
1058 // An overflowing conversion has undefined behavior if either the source type
1059 // or the destination type is a floating-point type.
1060 if (CGF.SanOpts.has(SanitizerKind::FloatCastOverflow) &&
1061 (OrigSrcType->isFloatingType() || DstType->isFloatingType()))
1062 EmitFloatConversionCheck(OrigSrc, OrigSrcType, Src, SrcType, DstType, DstTy,
1065 // Cast to half through float if half isn't a native type.
1066 if (DstType->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) {
1067 // Make sure we cast in a single step if from another FP type.
1068 if (SrcTy->isFloatingPointTy()) {
1069 // Use the intrinsic if the half type itself isn't supported
1070 // (as opposed to operations on half, available with NativeHalfType).
1071 if (CGF.getContext().getTargetInfo().useFP16ConversionIntrinsics())
1072 return Builder.CreateCall(
1073 CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16, SrcTy), Src);
1074 // If the half type is supported, just use an fptrunc.
1075 return Builder.CreateFPTrunc(Src, DstTy);
1077 DstTy = CGF.FloatTy;
1080 if (isa<llvm::IntegerType>(SrcTy)) {
1081 bool InputSigned = SrcType->isSignedIntegerOrEnumerationType();
1082 if (SrcType->isBooleanType() && TreatBooleanAsSigned) {
1085 if (isa<llvm::IntegerType>(DstTy))
1086 Res = Builder.CreateIntCast(Src, DstTy, InputSigned, "conv");
1087 else if (InputSigned)
1088 Res = Builder.CreateSIToFP(Src, DstTy, "conv");
1090 Res = Builder.CreateUIToFP(Src, DstTy, "conv");
1091 } else if (isa<llvm::IntegerType>(DstTy)) {
1092 assert(SrcTy->isFloatingPointTy() && "Unknown real conversion");
1093 if (DstType->isSignedIntegerOrEnumerationType())
1094 Res = Builder.CreateFPToSI(Src, DstTy, "conv");
1096 Res = Builder.CreateFPToUI(Src, DstTy, "conv");
1098 assert(SrcTy->isFloatingPointTy() && DstTy->isFloatingPointTy() &&
1099 "Unknown real conversion");
1100 if (DstTy->getTypeID() < SrcTy->getTypeID())
1101 Res = Builder.CreateFPTrunc(Src, DstTy, "conv");
1103 Res = Builder.CreateFPExt(Src, DstTy, "conv");
1106 if (DstTy != ResTy) {
1107 if (CGF.getContext().getTargetInfo().useFP16ConversionIntrinsics()) {
1108 assert(ResTy->isIntegerTy(16) && "Only half FP requires extra conversion");
1109 Res = Builder.CreateCall(
1110 CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16, CGF.CGM.FloatTy),
1113 Res = Builder.CreateFPTrunc(Res, ResTy, "conv");
1120 /// Emit a conversion from the specified complex type to the specified
1121 /// destination type, where the destination type is an LLVM scalar type.
1122 Value *ScalarExprEmitter::EmitComplexToScalarConversion(
1123 CodeGenFunction::ComplexPairTy Src, QualType SrcTy, QualType DstTy,
1124 SourceLocation Loc) {
1125 // Get the source element type.
1126 SrcTy = SrcTy->castAs<ComplexType>()->getElementType();
1128 // Handle conversions to bool first, they are special: comparisons against 0.
1129 if (DstTy->isBooleanType()) {
1130 // Complex != 0 -> (Real != 0) | (Imag != 0)
1131 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy, Loc);
1132 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy, Loc);
1133 return Builder.CreateOr(Src.first, Src.second, "tobool");
1136 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type,
1137 // the imaginary part of the complex value is discarded and the value of the
1138 // real part is converted according to the conversion rules for the
1139 // corresponding real type.
1140 return EmitScalarConversion(Src.first, SrcTy, DstTy, Loc);
1143 Value *ScalarExprEmitter::EmitNullValue(QualType Ty) {
1144 return CGF.EmitFromMemory(CGF.CGM.EmitNullConstant(Ty), Ty);
1147 /// \brief Emit a sanitization check for the given "binary" operation (which
1148 /// might actually be a unary increment which has been lowered to a binary
1149 /// operation). The check passes if all values in \p Checks (which are \c i1),
1151 void ScalarExprEmitter::EmitBinOpCheck(
1152 ArrayRef<std::pair<Value *, SanitizerMask>> Checks, const BinOpInfo &Info) {
1153 assert(CGF.IsSanitizerScope);
1154 SanitizerHandler Check;
1155 SmallVector<llvm::Constant *, 4> StaticData;
1156 SmallVector<llvm::Value *, 2> DynamicData;
1158 BinaryOperatorKind Opcode = Info.Opcode;
1159 if (BinaryOperator::isCompoundAssignmentOp(Opcode))
1160 Opcode = BinaryOperator::getOpForCompoundAssignment(Opcode);
1162 StaticData.push_back(CGF.EmitCheckSourceLocation(Info.E->getExprLoc()));
1163 const UnaryOperator *UO = dyn_cast<UnaryOperator>(Info.E);
1164 if (UO && UO->getOpcode() == UO_Minus) {
1165 Check = SanitizerHandler::NegateOverflow;
1166 StaticData.push_back(CGF.EmitCheckTypeDescriptor(UO->getType()));
1167 DynamicData.push_back(Info.RHS);
1169 if (BinaryOperator::isShiftOp(Opcode)) {
1170 // Shift LHS negative or too large, or RHS out of bounds.
1171 Check = SanitizerHandler::ShiftOutOfBounds;
1172 const BinaryOperator *BO = cast<BinaryOperator>(Info.E);
1173 StaticData.push_back(
1174 CGF.EmitCheckTypeDescriptor(BO->getLHS()->getType()));
1175 StaticData.push_back(
1176 CGF.EmitCheckTypeDescriptor(BO->getRHS()->getType()));
1177 } else if (Opcode == BO_Div || Opcode == BO_Rem) {
1178 // Divide or modulo by zero, or signed overflow (eg INT_MAX / -1).
1179 Check = SanitizerHandler::DivremOverflow;
1180 StaticData.push_back(CGF.EmitCheckTypeDescriptor(Info.Ty));
1182 // Arithmetic overflow (+, -, *).
1184 case BO_Add: Check = SanitizerHandler::AddOverflow; break;
1185 case BO_Sub: Check = SanitizerHandler::SubOverflow; break;
1186 case BO_Mul: Check = SanitizerHandler::MulOverflow; break;
1187 default: llvm_unreachable("unexpected opcode for bin op check");
1189 StaticData.push_back(CGF.EmitCheckTypeDescriptor(Info.Ty));
1191 DynamicData.push_back(Info.LHS);
1192 DynamicData.push_back(Info.RHS);
1195 CGF.EmitCheck(Checks, Check, StaticData, DynamicData);
1198 //===----------------------------------------------------------------------===//
1200 //===----------------------------------------------------------------------===//
1202 Value *ScalarExprEmitter::VisitExpr(Expr *E) {
1203 CGF.ErrorUnsupported(E, "scalar expression");
1204 if (E->getType()->isVoidType())
1206 return llvm::UndefValue::get(CGF.ConvertType(E->getType()));
1209 Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) {
1211 if (E->getNumSubExprs() == 2) {
1212 Value *LHS = CGF.EmitScalarExpr(E->getExpr(0));
1213 Value *RHS = CGF.EmitScalarExpr(E->getExpr(1));
1216 llvm::VectorType *LTy = cast<llvm::VectorType>(LHS->getType());
1217 unsigned LHSElts = LTy->getNumElements();
1221 llvm::VectorType *MTy = cast<llvm::VectorType>(Mask->getType());
1223 // Mask off the high bits of each shuffle index.
1225 llvm::ConstantInt::get(MTy, llvm::NextPowerOf2(LHSElts - 1) - 1);
1226 Mask = Builder.CreateAnd(Mask, MaskBits, "mask");
1229 // mask = mask & maskbits
1231 // n = extract mask i
1232 // x = extract val n
1233 // newv = insert newv, x, i
1234 llvm::VectorType *RTy = llvm::VectorType::get(LTy->getElementType(),
1235 MTy->getNumElements());
1236 Value* NewV = llvm::UndefValue::get(RTy);
1237 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) {
1238 Value *IIndx = llvm::ConstantInt::get(CGF.SizeTy, i);
1239 Value *Indx = Builder.CreateExtractElement(Mask, IIndx, "shuf_idx");
1241 Value *VExt = Builder.CreateExtractElement(LHS, Indx, "shuf_elt");
1242 NewV = Builder.CreateInsertElement(NewV, VExt, IIndx, "shuf_ins");
1247 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0));
1248 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1));
1250 SmallVector<llvm::Constant*, 32> indices;
1251 for (unsigned i = 2; i < E->getNumSubExprs(); ++i) {
1252 llvm::APSInt Idx = E->getShuffleMaskIdx(CGF.getContext(), i-2);
1253 // Check for -1 and output it as undef in the IR.
1254 if (Idx.isSigned() && Idx.isAllOnesValue())
1255 indices.push_back(llvm::UndefValue::get(CGF.Int32Ty));
1257 indices.push_back(Builder.getInt32(Idx.getZExtValue()));
1260 Value *SV = llvm::ConstantVector::get(indices);
1261 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle");
1264 Value *ScalarExprEmitter::VisitConvertVectorExpr(ConvertVectorExpr *E) {
1265 QualType SrcType = E->getSrcExpr()->getType(),
1266 DstType = E->getType();
1268 Value *Src = CGF.EmitScalarExpr(E->getSrcExpr());
1270 SrcType = CGF.getContext().getCanonicalType(SrcType);
1271 DstType = CGF.getContext().getCanonicalType(DstType);
1272 if (SrcType == DstType) return Src;
1274 assert(SrcType->isVectorType() &&
1275 "ConvertVector source type must be a vector");
1276 assert(DstType->isVectorType() &&
1277 "ConvertVector destination type must be a vector");
1279 llvm::Type *SrcTy = Src->getType();
1280 llvm::Type *DstTy = ConvertType(DstType);
1282 // Ignore conversions like int -> uint.
1286 QualType SrcEltType = SrcType->getAs<VectorType>()->getElementType(),
1287 DstEltType = DstType->getAs<VectorType>()->getElementType();
1289 assert(SrcTy->isVectorTy() &&
1290 "ConvertVector source IR type must be a vector");
1291 assert(DstTy->isVectorTy() &&
1292 "ConvertVector destination IR type must be a vector");
1294 llvm::Type *SrcEltTy = SrcTy->getVectorElementType(),
1295 *DstEltTy = DstTy->getVectorElementType();
1297 if (DstEltType->isBooleanType()) {
1298 assert((SrcEltTy->isFloatingPointTy() ||
1299 isa<llvm::IntegerType>(SrcEltTy)) && "Unknown boolean conversion");
1301 llvm::Value *Zero = llvm::Constant::getNullValue(SrcTy);
1302 if (SrcEltTy->isFloatingPointTy()) {
1303 return Builder.CreateFCmpUNE(Src, Zero, "tobool");
1305 return Builder.CreateICmpNE(Src, Zero, "tobool");
1309 // We have the arithmetic types: real int/float.
1310 Value *Res = nullptr;
1312 if (isa<llvm::IntegerType>(SrcEltTy)) {
1313 bool InputSigned = SrcEltType->isSignedIntegerOrEnumerationType();
1314 if (isa<llvm::IntegerType>(DstEltTy))
1315 Res = Builder.CreateIntCast(Src, DstTy, InputSigned, "conv");
1316 else if (InputSigned)
1317 Res = Builder.CreateSIToFP(Src, DstTy, "conv");
1319 Res = Builder.CreateUIToFP(Src, DstTy, "conv");
1320 } else if (isa<llvm::IntegerType>(DstEltTy)) {
1321 assert(SrcEltTy->isFloatingPointTy() && "Unknown real conversion");
1322 if (DstEltType->isSignedIntegerOrEnumerationType())
1323 Res = Builder.CreateFPToSI(Src, DstTy, "conv");
1325 Res = Builder.CreateFPToUI(Src, DstTy, "conv");
1327 assert(SrcEltTy->isFloatingPointTy() && DstEltTy->isFloatingPointTy() &&
1328 "Unknown real conversion");
1329 if (DstEltTy->getTypeID() < SrcEltTy->getTypeID())
1330 Res = Builder.CreateFPTrunc(Src, DstTy, "conv");
1332 Res = Builder.CreateFPExt(Src, DstTy, "conv");
1338 Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) {
1339 if (CodeGenFunction::ConstantEmission Constant = CGF.tryEmitAsConstant(E)) {
1340 CGF.EmitIgnoredExpr(E->getBase());
1341 return emitConstant(Constant, E);
1344 if (E->EvaluateAsInt(Value, CGF.getContext(), Expr::SE_AllowSideEffects)) {
1345 CGF.EmitIgnoredExpr(E->getBase());
1346 return Builder.getInt(Value);
1350 return EmitLoadOfLValue(E);
1353 Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
1354 TestAndClearIgnoreResultAssign();
1356 // Emit subscript expressions in rvalue context's. For most cases, this just
1357 // loads the lvalue formed by the subscript expr. However, we have to be
1358 // careful, because the base of a vector subscript is occasionally an rvalue,
1359 // so we can't get it as an lvalue.
1360 if (!E->getBase()->getType()->isVectorType())
1361 return EmitLoadOfLValue(E);
1363 // Handle the vector case. The base must be a vector, the index must be an
1365 Value *Base = Visit(E->getBase());
1366 Value *Idx = Visit(E->getIdx());
1367 QualType IdxTy = E->getIdx()->getType();
1369 if (CGF.SanOpts.has(SanitizerKind::ArrayBounds))
1370 CGF.EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, /*Accessed*/true);
1372 return Builder.CreateExtractElement(Base, Idx, "vecext");
1375 static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx,
1376 unsigned Off, llvm::Type *I32Ty) {
1377 int MV = SVI->getMaskValue(Idx);
1379 return llvm::UndefValue::get(I32Ty);
1380 return llvm::ConstantInt::get(I32Ty, Off+MV);
1383 static llvm::Constant *getAsInt32(llvm::ConstantInt *C, llvm::Type *I32Ty) {
1384 if (C->getBitWidth() != 32) {
1385 assert(llvm::ConstantInt::isValueValidForType(I32Ty,
1386 C->getZExtValue()) &&
1387 "Index operand too large for shufflevector mask!");
1388 return llvm::ConstantInt::get(I32Ty, C->getZExtValue());
1393 Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) {
1394 bool Ignore = TestAndClearIgnoreResultAssign();
1396 assert (Ignore == false && "init list ignored");
1397 unsigned NumInitElements = E->getNumInits();
1399 if (E->hadArrayRangeDesignator())
1400 CGF.ErrorUnsupported(E, "GNU array range designator extension");
1402 llvm::VectorType *VType =
1403 dyn_cast<llvm::VectorType>(ConvertType(E->getType()));
1406 if (NumInitElements == 0) {
1407 // C++11 value-initialization for the scalar.
1408 return EmitNullValue(E->getType());
1410 // We have a scalar in braces. Just use the first element.
1411 return Visit(E->getInit(0));
1414 unsigned ResElts = VType->getNumElements();
1416 // Loop over initializers collecting the Value for each, and remembering
1417 // whether the source was swizzle (ExtVectorElementExpr). This will allow
1418 // us to fold the shuffle for the swizzle into the shuffle for the vector
1419 // initializer, since LLVM optimizers generally do not want to touch
1421 unsigned CurIdx = 0;
1422 bool VIsUndefShuffle = false;
1423 llvm::Value *V = llvm::UndefValue::get(VType);
1424 for (unsigned i = 0; i != NumInitElements; ++i) {
1425 Expr *IE = E->getInit(i);
1426 Value *Init = Visit(IE);
1427 SmallVector<llvm::Constant*, 16> Args;
1429 llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType());
1431 // Handle scalar elements. If the scalar initializer is actually one
1432 // element of a different vector of the same width, use shuffle instead of
1435 if (isa<ExtVectorElementExpr>(IE)) {
1436 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init);
1438 if (EI->getVectorOperandType()->getNumElements() == ResElts) {
1439 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand());
1440 Value *LHS = nullptr, *RHS = nullptr;
1442 // insert into undef -> shuffle (src, undef)
1443 // shufflemask must use an i32
1444 Args.push_back(getAsInt32(C, CGF.Int32Ty));
1445 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
1447 LHS = EI->getVectorOperand();
1449 VIsUndefShuffle = true;
1450 } else if (VIsUndefShuffle) {
1451 // insert into undefshuffle && size match -> shuffle (v, src)
1452 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V);
1453 for (unsigned j = 0; j != CurIdx; ++j)
1454 Args.push_back(getMaskElt(SVV, j, 0, CGF.Int32Ty));
1455 Args.push_back(Builder.getInt32(ResElts + C->getZExtValue()));
1456 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
1458 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0);
1459 RHS = EI->getVectorOperand();
1460 VIsUndefShuffle = false;
1462 if (!Args.empty()) {
1463 llvm::Constant *Mask = llvm::ConstantVector::get(Args);
1464 V = Builder.CreateShuffleVector(LHS, RHS, Mask);
1470 V = Builder.CreateInsertElement(V, Init, Builder.getInt32(CurIdx),
1472 VIsUndefShuffle = false;
1477 unsigned InitElts = VVT->getNumElements();
1479 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's
1480 // input is the same width as the vector being constructed, generate an
1481 // optimized shuffle of the swizzle input into the result.
1482 unsigned Offset = (CurIdx == 0) ? 0 : ResElts;
1483 if (isa<ExtVectorElementExpr>(IE)) {
1484 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init);
1485 Value *SVOp = SVI->getOperand(0);
1486 llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType());
1488 if (OpTy->getNumElements() == ResElts) {
1489 for (unsigned j = 0; j != CurIdx; ++j) {
1490 // If the current vector initializer is a shuffle with undef, merge
1491 // this shuffle directly into it.
1492 if (VIsUndefShuffle) {
1493 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0,
1496 Args.push_back(Builder.getInt32(j));
1499 for (unsigned j = 0, je = InitElts; j != je; ++j)
1500 Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty));
1501 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
1503 if (VIsUndefShuffle)
1504 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0);
1510 // Extend init to result vector length, and then shuffle its contribution
1511 // to the vector initializer into V.
1513 for (unsigned j = 0; j != InitElts; ++j)
1514 Args.push_back(Builder.getInt32(j));
1515 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
1516 llvm::Constant *Mask = llvm::ConstantVector::get(Args);
1517 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT),
1521 for (unsigned j = 0; j != CurIdx; ++j)
1522 Args.push_back(Builder.getInt32(j));
1523 for (unsigned j = 0; j != InitElts; ++j)
1524 Args.push_back(Builder.getInt32(j+Offset));
1525 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
1528 // If V is undef, make sure it ends up on the RHS of the shuffle to aid
1529 // merging subsequent shuffles into this one.
1532 llvm::Constant *Mask = llvm::ConstantVector::get(Args);
1533 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit");
1534 VIsUndefShuffle = isa<llvm::UndefValue>(Init);
1538 // FIXME: evaluate codegen vs. shuffling against constant null vector.
1539 // Emit remaining default initializers.
1540 llvm::Type *EltTy = VType->getElementType();
1542 // Emit remaining default initializers
1543 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) {
1544 Value *Idx = Builder.getInt32(CurIdx);
1545 llvm::Value *Init = llvm::Constant::getNullValue(EltTy);
1546 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit");
1551 bool CodeGenFunction::ShouldNullCheckClassCastValue(const CastExpr *CE) {
1552 const Expr *E = CE->getSubExpr();
1554 if (CE->getCastKind() == CK_UncheckedDerivedToBase)
1557 if (isa<CXXThisExpr>(E->IgnoreParens())) {
1558 // We always assume that 'this' is never null.
1562 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) {
1563 // And that glvalue casts are never null.
1564 if (ICE->getValueKind() != VK_RValue)
1571 // VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts
1572 // have to handle a more broad range of conversions than explicit casts, as they
1573 // handle things like function to ptr-to-function decay etc.
1574 Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) {
1575 Expr *E = CE->getSubExpr();
1576 QualType DestTy = CE->getType();
1577 CastKind Kind = CE->getCastKind();
1579 // These cases are generally not written to ignore the result of
1580 // evaluating their sub-expressions, so we clear this now.
1581 bool Ignored = TestAndClearIgnoreResultAssign();
1583 // Since almost all cast kinds apply to scalars, this switch doesn't have
1584 // a default case, so the compiler will warn on a missing case. The cases
1585 // are in the same order as in the CastKind enum.
1587 case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!");
1588 case CK_BuiltinFnToFnPtr:
1589 llvm_unreachable("builtin functions are handled elsewhere");
1591 case CK_LValueBitCast:
1592 case CK_ObjCObjectLValueCast: {
1593 Address Addr = EmitLValue(E).getAddress();
1594 Addr = Builder.CreateElementBitCast(Addr, CGF.ConvertTypeForMem(DestTy));
1595 LValue LV = CGF.MakeAddrLValue(Addr, DestTy);
1596 return EmitLoadOfLValue(LV, CE->getExprLoc());
1599 case CK_CPointerToObjCPointerCast:
1600 case CK_BlockPointerToObjCPointerCast:
1601 case CK_AnyPointerToBlockPointerCast:
1603 Value *Src = Visit(const_cast<Expr*>(E));
1604 llvm::Type *SrcTy = Src->getType();
1605 llvm::Type *DstTy = ConvertType(DestTy);
1606 if (SrcTy->isPtrOrPtrVectorTy() && DstTy->isPtrOrPtrVectorTy() &&
1607 SrcTy->getPointerAddressSpace() != DstTy->getPointerAddressSpace()) {
1608 llvm_unreachable("wrong cast for pointers in different address spaces"
1609 "(must be an address space cast)!");
1612 if (CGF.SanOpts.has(SanitizerKind::CFIUnrelatedCast)) {
1613 if (auto PT = DestTy->getAs<PointerType>())
1614 CGF.EmitVTablePtrCheckForCast(PT->getPointeeType(), Src,
1616 CodeGenFunction::CFITCK_UnrelatedCast,
1620 return Builder.CreateBitCast(Src, DstTy);
1622 case CK_AddressSpaceConversion: {
1623 Expr::EvalResult Result;
1624 if (E->EvaluateAsRValue(Result, CGF.getContext()) &&
1625 Result.Val.isNullPointer()) {
1626 // If E has side effect, it is emitted even if its final result is a
1627 // null pointer. In that case, a DCE pass should be able to
1628 // eliminate the useless instructions emitted during translating E.
1629 if (Result.HasSideEffects)
1631 return CGF.CGM.getNullPointer(cast<llvm::PointerType>(
1632 ConvertType(DestTy)), DestTy);
1634 // Since target may map different address spaces in AST to the same address
1635 // space, an address space conversion may end up as a bitcast.
1636 return CGF.CGM.getTargetCodeGenInfo().performAddrSpaceCast(
1637 CGF, Visit(E), E->getType()->getPointeeType().getAddressSpace(),
1638 DestTy->getPointeeType().getAddressSpace(), ConvertType(DestTy));
1640 case CK_AtomicToNonAtomic:
1641 case CK_NonAtomicToAtomic:
1643 case CK_UserDefinedConversion:
1644 return Visit(const_cast<Expr*>(E));
1646 case CK_BaseToDerived: {
1647 const CXXRecordDecl *DerivedClassDecl = DestTy->getPointeeCXXRecordDecl();
1648 assert(DerivedClassDecl && "BaseToDerived arg isn't a C++ object pointer!");
1650 Address Base = CGF.EmitPointerWithAlignment(E);
1652 CGF.GetAddressOfDerivedClass(Base, DerivedClassDecl,
1653 CE->path_begin(), CE->path_end(),
1654 CGF.ShouldNullCheckClassCastValue(CE));
1656 // C++11 [expr.static.cast]p11: Behavior is undefined if a downcast is
1657 // performed and the object is not of the derived type.
1658 if (CGF.sanitizePerformTypeCheck())
1659 CGF.EmitTypeCheck(CodeGenFunction::TCK_DowncastPointer, CE->getExprLoc(),
1660 Derived.getPointer(), DestTy->getPointeeType());
1662 if (CGF.SanOpts.has(SanitizerKind::CFIDerivedCast))
1663 CGF.EmitVTablePtrCheckForCast(DestTy->getPointeeType(),
1664 Derived.getPointer(),
1666 CodeGenFunction::CFITCK_DerivedCast,
1669 return Derived.getPointer();
1671 case CK_UncheckedDerivedToBase:
1672 case CK_DerivedToBase: {
1673 // The EmitPointerWithAlignment path does this fine; just discard
1675 return CGF.EmitPointerWithAlignment(CE).getPointer();
1679 Address V = CGF.EmitPointerWithAlignment(E);
1680 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE);
1681 return CGF.EmitDynamicCast(V, DCE);
1684 case CK_ArrayToPointerDecay:
1685 return CGF.EmitArrayToPointerDecay(E).getPointer();
1686 case CK_FunctionToPointerDecay:
1687 return EmitLValue(E).getPointer();
1689 case CK_NullToPointer:
1690 if (MustVisitNullValue(E))
1693 return CGF.CGM.getNullPointer(cast<llvm::PointerType>(ConvertType(DestTy)),
1696 case CK_NullToMemberPointer: {
1697 if (MustVisitNullValue(E))
1700 const MemberPointerType *MPT = CE->getType()->getAs<MemberPointerType>();
1701 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT);
1704 case CK_ReinterpretMemberPointer:
1705 case CK_BaseToDerivedMemberPointer:
1706 case CK_DerivedToBaseMemberPointer: {
1707 Value *Src = Visit(E);
1709 // Note that the AST doesn't distinguish between checked and
1710 // unchecked member pointer conversions, so we always have to
1711 // implement checked conversions here. This is inefficient when
1712 // actual control flow may be required in order to perform the
1713 // check, which it is for data member pointers (but not member
1714 // function pointers on Itanium and ARM).
1715 return CGF.CGM.getCXXABI().EmitMemberPointerConversion(CGF, CE, Src);
1718 case CK_ARCProduceObject:
1719 return CGF.EmitARCRetainScalarExpr(E);
1720 case CK_ARCConsumeObject:
1721 return CGF.EmitObjCConsumeObject(E->getType(), Visit(E));
1722 case CK_ARCReclaimReturnedObject:
1723 return CGF.EmitARCReclaimReturnedObject(E, /*allowUnsafe*/ Ignored);
1724 case CK_ARCExtendBlockObject:
1725 return CGF.EmitARCExtendBlockObject(E);
1727 case CK_CopyAndAutoreleaseBlockObject:
1728 return CGF.EmitBlockCopyAndAutorelease(Visit(E), E->getType());
1730 case CK_FloatingRealToComplex:
1731 case CK_FloatingComplexCast:
1732 case CK_IntegralRealToComplex:
1733 case CK_IntegralComplexCast:
1734 case CK_IntegralComplexToFloatingComplex:
1735 case CK_FloatingComplexToIntegralComplex:
1736 case CK_ConstructorConversion:
1738 llvm_unreachable("scalar cast to non-scalar value");
1740 case CK_LValueToRValue:
1741 assert(CGF.getContext().hasSameUnqualifiedType(E->getType(), DestTy));
1742 assert(E->isGLValue() && "lvalue-to-rvalue applied to r-value!");
1743 return Visit(const_cast<Expr*>(E));
1745 case CK_IntegralToPointer: {
1746 Value *Src = Visit(const_cast<Expr*>(E));
1748 // First, convert to the correct width so that we control the kind of
1750 auto DestLLVMTy = ConvertType(DestTy);
1751 llvm::Type *MiddleTy = CGF.CGM.getDataLayout().getIntPtrType(DestLLVMTy);
1752 bool InputSigned = E->getType()->isSignedIntegerOrEnumerationType();
1753 llvm::Value* IntResult =
1754 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv");
1756 return Builder.CreateIntToPtr(IntResult, DestLLVMTy);
1758 case CK_PointerToIntegral:
1759 assert(!DestTy->isBooleanType() && "bool should use PointerToBool");
1760 return Builder.CreatePtrToInt(Visit(E), ConvertType(DestTy));
1763 CGF.EmitIgnoredExpr(E);
1766 case CK_VectorSplat: {
1767 llvm::Type *DstTy = ConvertType(DestTy);
1768 Value *Elt = Visit(const_cast<Expr*>(E));
1769 // Splat the element across to all elements
1770 unsigned NumElements = DstTy->getVectorNumElements();
1771 return Builder.CreateVectorSplat(NumElements, Elt, "splat");
1774 case CK_IntegralCast:
1775 case CK_IntegralToFloating:
1776 case CK_FloatingToIntegral:
1777 case CK_FloatingCast:
1778 return EmitScalarConversion(Visit(E), E->getType(), DestTy,
1780 case CK_BooleanToSignedIntegral:
1781 return EmitScalarConversion(Visit(E), E->getType(), DestTy,
1783 /*TreatBooleanAsSigned=*/true);
1784 case CK_IntegralToBoolean:
1785 return EmitIntToBoolConversion(Visit(E));
1786 case CK_PointerToBoolean:
1787 return EmitPointerToBoolConversion(Visit(E), E->getType());
1788 case CK_FloatingToBoolean:
1789 return EmitFloatToBoolConversion(Visit(E));
1790 case CK_MemberPointerToBoolean: {
1791 llvm::Value *MemPtr = Visit(E);
1792 const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>();
1793 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT);
1796 case CK_FloatingComplexToReal:
1797 case CK_IntegralComplexToReal:
1798 return CGF.EmitComplexExpr(E, false, true).first;
1800 case CK_FloatingComplexToBoolean:
1801 case CK_IntegralComplexToBoolean: {
1802 CodeGenFunction::ComplexPairTy V = CGF.EmitComplexExpr(E);
1804 // TODO: kill this function off, inline appropriate case here
1805 return EmitComplexToScalarConversion(V, E->getType(), DestTy,
1809 case CK_ZeroToOCLEvent: {
1810 assert(DestTy->isEventT() && "CK_ZeroToOCLEvent cast on non-event type");
1811 return llvm::Constant::getNullValue(ConvertType(DestTy));
1814 case CK_ZeroToOCLQueue: {
1815 assert(DestTy->isQueueT() && "CK_ZeroToOCLQueue cast on non queue_t type");
1816 return llvm::Constant::getNullValue(ConvertType(DestTy));
1819 case CK_IntToOCLSampler:
1820 return CGF.CGM.createOpenCLIntToSamplerConversion(E, CGF);
1824 llvm_unreachable("unknown scalar cast");
1827 Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) {
1828 CodeGenFunction::StmtExprEvaluation eval(CGF);
1829 Address RetAlloca = CGF.EmitCompoundStmt(*E->getSubStmt(),
1830 !E->getType()->isVoidType());
1831 if (!RetAlloca.isValid())
1833 return CGF.EmitLoadOfScalar(CGF.MakeAddrLValue(RetAlloca, E->getType()),
1837 Value *ScalarExprEmitter::VisitExprWithCleanups(ExprWithCleanups *E) {
1838 CGF.enterFullExpression(E);
1839 CodeGenFunction::RunCleanupsScope Scope(CGF);
1840 Value *V = Visit(E->getSubExpr());
1841 // Defend against dominance problems caused by jumps out of expression
1842 // evaluation through the shared cleanup block.
1843 Scope.ForceCleanup({&V});
1847 //===----------------------------------------------------------------------===//
1849 //===----------------------------------------------------------------------===//
1851 static BinOpInfo createBinOpInfoFromIncDec(const UnaryOperator *E,
1852 llvm::Value *InVal, bool IsInc) {
1855 BinOp.RHS = llvm::ConstantInt::get(InVal->getType(), 1, false);
1856 BinOp.Ty = E->getType();
1857 BinOp.Opcode = IsInc ? BO_Add : BO_Sub;
1858 // FIXME: once UnaryOperator carries FPFeatures, copy it here.
1863 llvm::Value *ScalarExprEmitter::EmitIncDecConsiderOverflowBehavior(
1864 const UnaryOperator *E, llvm::Value *InVal, bool IsInc) {
1865 llvm::Value *Amount =
1866 llvm::ConstantInt::get(InVal->getType(), IsInc ? 1 : -1, true);
1867 StringRef Name = IsInc ? "inc" : "dec";
1868 switch (CGF.getLangOpts().getSignedOverflowBehavior()) {
1869 case LangOptions::SOB_Defined:
1870 return Builder.CreateAdd(InVal, Amount, Name);
1871 case LangOptions::SOB_Undefined:
1872 if (!CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow))
1873 return Builder.CreateNSWAdd(InVal, Amount, Name);
1875 case LangOptions::SOB_Trapping:
1876 if (IsWidenedIntegerOp(CGF.getContext(), E->getSubExpr()))
1877 return Builder.CreateNSWAdd(InVal, Amount, Name);
1878 return EmitOverflowCheckedBinOp(createBinOpInfoFromIncDec(E, InVal, IsInc));
1880 llvm_unreachable("Unknown SignedOverflowBehaviorTy");
1884 ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
1885 bool isInc, bool isPre) {
1887 QualType type = E->getSubExpr()->getType();
1888 llvm::PHINode *atomicPHI = nullptr;
1892 int amount = (isInc ? 1 : -1);
1893 bool isSubtraction = !isInc;
1895 if (const AtomicType *atomicTy = type->getAs<AtomicType>()) {
1896 type = atomicTy->getValueType();
1897 if (isInc && type->isBooleanType()) {
1898 llvm::Value *True = CGF.EmitToMemory(Builder.getTrue(), type);
1900 Builder.CreateStore(True, LV.getAddress(), LV.isVolatileQualified())
1901 ->setAtomic(llvm::AtomicOrdering::SequentiallyConsistent);
1902 return Builder.getTrue();
1904 // For atomic bool increment, we just store true and return it for
1905 // preincrement, do an atomic swap with true for postincrement
1906 return Builder.CreateAtomicRMW(
1907 llvm::AtomicRMWInst::Xchg, LV.getPointer(), True,
1908 llvm::AtomicOrdering::SequentiallyConsistent);
1910 // Special case for atomic increment / decrement on integers, emit
1911 // atomicrmw instructions. We skip this if we want to be doing overflow
1912 // checking, and fall into the slow path with the atomic cmpxchg loop.
1913 if (!type->isBooleanType() && type->isIntegerType() &&
1914 !(type->isUnsignedIntegerType() &&
1915 CGF.SanOpts.has(SanitizerKind::UnsignedIntegerOverflow)) &&
1916 CGF.getLangOpts().getSignedOverflowBehavior() !=
1917 LangOptions::SOB_Trapping) {
1918 llvm::AtomicRMWInst::BinOp aop = isInc ? llvm::AtomicRMWInst::Add :
1919 llvm::AtomicRMWInst::Sub;
1920 llvm::Instruction::BinaryOps op = isInc ? llvm::Instruction::Add :
1921 llvm::Instruction::Sub;
1922 llvm::Value *amt = CGF.EmitToMemory(
1923 llvm::ConstantInt::get(ConvertType(type), 1, true), type);
1924 llvm::Value *old = Builder.CreateAtomicRMW(aop,
1925 LV.getPointer(), amt, llvm::AtomicOrdering::SequentiallyConsistent);
1926 return isPre ? Builder.CreateBinOp(op, old, amt) : old;
1928 value = EmitLoadOfLValue(LV, E->getExprLoc());
1930 // For every other atomic operation, we need to emit a load-op-cmpxchg loop
1931 llvm::BasicBlock *startBB = Builder.GetInsertBlock();
1932 llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn);
1933 value = CGF.EmitToMemory(value, type);
1934 Builder.CreateBr(opBB);
1935 Builder.SetInsertPoint(opBB);
1936 atomicPHI = Builder.CreatePHI(value->getType(), 2);
1937 atomicPHI->addIncoming(value, startBB);
1940 value = EmitLoadOfLValue(LV, E->getExprLoc());
1944 // Special case of integer increment that we have to check first: bool++.
1945 // Due to promotion rules, we get:
1946 // bool++ -> bool = bool + 1
1947 // -> bool = (int)bool + 1
1948 // -> bool = ((int)bool + 1 != 0)
1949 // An interesting aspect of this is that increment is always true.
1950 // Decrement does not have this property.
1951 if (isInc && type->isBooleanType()) {
1952 value = Builder.getTrue();
1954 // Most common case by far: integer increment.
1955 } else if (type->isIntegerType()) {
1956 // Note that signed integer inc/dec with width less than int can't
1957 // overflow because of promotion rules; we're just eliding a few steps here.
1958 bool CanOverflow = value->getType()->getIntegerBitWidth() >=
1959 CGF.IntTy->getIntegerBitWidth();
1960 if (CanOverflow && type->isSignedIntegerOrEnumerationType()) {
1961 value = EmitIncDecConsiderOverflowBehavior(E, value, isInc);
1962 } else if (CanOverflow && type->isUnsignedIntegerType() &&
1963 CGF.SanOpts.has(SanitizerKind::UnsignedIntegerOverflow)) {
1965 EmitOverflowCheckedBinOp(createBinOpInfoFromIncDec(E, value, isInc));
1967 llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount, true);
1968 value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec");
1971 // Next most common: pointer increment.
1972 } else if (const PointerType *ptr = type->getAs<PointerType>()) {
1973 QualType type = ptr->getPointeeType();
1975 // VLA types don't have constant size.
1976 if (const VariableArrayType *vla
1977 = CGF.getContext().getAsVariableArrayType(type)) {
1978 llvm::Value *numElts = CGF.getVLASize(vla).first;
1979 if (!isInc) numElts = Builder.CreateNSWNeg(numElts, "vla.negsize");
1980 if (CGF.getLangOpts().isSignedOverflowDefined())
1981 value = Builder.CreateGEP(value, numElts, "vla.inc");
1983 value = CGF.EmitCheckedInBoundsGEP(
1984 value, numElts, /*SignedIndices=*/false, isSubtraction,
1985 E->getExprLoc(), "vla.inc");
1987 // Arithmetic on function pointers (!) is just +-1.
1988 } else if (type->isFunctionType()) {
1989 llvm::Value *amt = Builder.getInt32(amount);
1991 value = CGF.EmitCastToVoidPtr(value);
1992 if (CGF.getLangOpts().isSignedOverflowDefined())
1993 value = Builder.CreateGEP(value, amt, "incdec.funcptr");
1995 value = CGF.EmitCheckedInBoundsGEP(value, amt, /*SignedIndices=*/false,
1996 isSubtraction, E->getExprLoc(),
1998 value = Builder.CreateBitCast(value, input->getType());
2000 // For everything else, we can just do a simple increment.
2002 llvm::Value *amt = Builder.getInt32(amount);
2003 if (CGF.getLangOpts().isSignedOverflowDefined())
2004 value = Builder.CreateGEP(value, amt, "incdec.ptr");
2006 value = CGF.EmitCheckedInBoundsGEP(value, amt, /*SignedIndices=*/false,
2007 isSubtraction, E->getExprLoc(),
2011 // Vector increment/decrement.
2012 } else if (type->isVectorType()) {
2013 if (type->hasIntegerRepresentation()) {
2014 llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount);
2016 value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec");
2018 value = Builder.CreateFAdd(
2020 llvm::ConstantFP::get(value->getType(), amount),
2021 isInc ? "inc" : "dec");
2025 } else if (type->isRealFloatingType()) {
2026 // Add the inc/dec to the real part.
2029 if (type->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) {
2030 // Another special case: half FP increment should be done via float
2031 if (CGF.getContext().getTargetInfo().useFP16ConversionIntrinsics()) {
2032 value = Builder.CreateCall(
2033 CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16,
2035 input, "incdec.conv");
2037 value = Builder.CreateFPExt(input, CGF.CGM.FloatTy, "incdec.conv");
2041 if (value->getType()->isFloatTy())
2042 amt = llvm::ConstantFP::get(VMContext,
2043 llvm::APFloat(static_cast<float>(amount)));
2044 else if (value->getType()->isDoubleTy())
2045 amt = llvm::ConstantFP::get(VMContext,
2046 llvm::APFloat(static_cast<double>(amount)));
2048 // Remaining types are Half, LongDouble or __float128. Convert from float.
2049 llvm::APFloat F(static_cast<float>(amount));
2051 const llvm::fltSemantics *FS;
2052 // Don't use getFloatTypeSemantics because Half isn't
2053 // necessarily represented using the "half" LLVM type.
2054 if (value->getType()->isFP128Ty())
2055 FS = &CGF.getTarget().getFloat128Format();
2056 else if (value->getType()->isHalfTy())
2057 FS = &CGF.getTarget().getHalfFormat();
2059 FS = &CGF.getTarget().getLongDoubleFormat();
2060 F.convert(*FS, llvm::APFloat::rmTowardZero, &ignored);
2061 amt = llvm::ConstantFP::get(VMContext, F);
2063 value = Builder.CreateFAdd(value, amt, isInc ? "inc" : "dec");
2065 if (type->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) {
2066 if (CGF.getContext().getTargetInfo().useFP16ConversionIntrinsics()) {
2067 value = Builder.CreateCall(
2068 CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16,
2070 value, "incdec.conv");
2072 value = Builder.CreateFPTrunc(value, input->getType(), "incdec.conv");
2076 // Objective-C pointer types.
2078 const ObjCObjectPointerType *OPT = type->castAs<ObjCObjectPointerType>();
2079 value = CGF.EmitCastToVoidPtr(value);
2081 CharUnits size = CGF.getContext().getTypeSizeInChars(OPT->getObjectType());
2082 if (!isInc) size = -size;
2083 llvm::Value *sizeValue =
2084 llvm::ConstantInt::get(CGF.SizeTy, size.getQuantity());
2086 if (CGF.getLangOpts().isSignedOverflowDefined())
2087 value = Builder.CreateGEP(value, sizeValue, "incdec.objptr");
2089 value = CGF.EmitCheckedInBoundsGEP(value, sizeValue,
2090 /*SignedIndices=*/false, isSubtraction,
2091 E->getExprLoc(), "incdec.objptr");
2092 value = Builder.CreateBitCast(value, input->getType());
2096 llvm::BasicBlock *opBB = Builder.GetInsertBlock();
2097 llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn);
2098 auto Pair = CGF.EmitAtomicCompareExchange(
2099 LV, RValue::get(atomicPHI), RValue::get(value), E->getExprLoc());
2100 llvm::Value *old = CGF.EmitToMemory(Pair.first.getScalarVal(), type);
2101 llvm::Value *success = Pair.second;
2102 atomicPHI->addIncoming(old, opBB);
2103 Builder.CreateCondBr(success, contBB, opBB);
2104 Builder.SetInsertPoint(contBB);
2105 return isPre ? value : input;
2108 // Store the updated result through the lvalue.
2109 if (LV.isBitField())
2110 CGF.EmitStoreThroughBitfieldLValue(RValue::get(value), LV, &value);
2112 CGF.EmitStoreThroughLValue(RValue::get(value), LV);
2114 // If this is a postinc, return the value read from memory, otherwise use the
2116 return isPre ? value : input;
2121 Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
2122 TestAndClearIgnoreResultAssign();
2123 // Emit unary minus with EmitSub so we handle overflow cases etc.
2125 BinOp.RHS = Visit(E->getSubExpr());
2127 if (BinOp.RHS->getType()->isFPOrFPVectorTy())
2128 BinOp.LHS = llvm::ConstantFP::getZeroValueForNegation(BinOp.RHS->getType());
2130 BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType());
2131 BinOp.Ty = E->getType();
2132 BinOp.Opcode = BO_Sub;
2133 // FIXME: once UnaryOperator carries FPFeatures, copy it here.
2135 return EmitSub(BinOp);
2138 Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
2139 TestAndClearIgnoreResultAssign();
2140 Value *Op = Visit(E->getSubExpr());
2141 return Builder.CreateNot(Op, "neg");
2144 Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) {
2145 // Perform vector logical not on comparison with zero vector.
2146 if (E->getType()->isExtVectorType()) {
2147 Value *Oper = Visit(E->getSubExpr());
2148 Value *Zero = llvm::Constant::getNullValue(Oper->getType());
2150 if (Oper->getType()->isFPOrFPVectorTy())
2151 Result = Builder.CreateFCmp(llvm::CmpInst::FCMP_OEQ, Oper, Zero, "cmp");
2153 Result = Builder.CreateICmp(llvm::CmpInst::ICMP_EQ, Oper, Zero, "cmp");
2154 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext");
2157 // Compare operand to zero.
2158 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr());
2161 // TODO: Could dynamically modify easy computations here. For example, if
2162 // the operand is an icmp ne, turn into icmp eq.
2163 BoolVal = Builder.CreateNot(BoolVal, "lnot");
2165 // ZExt result to the expr type.
2166 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext");
2169 Value *ScalarExprEmitter::VisitOffsetOfExpr(OffsetOfExpr *E) {
2170 // Try folding the offsetof to a constant.
2172 if (E->EvaluateAsInt(Value, CGF.getContext()))
2173 return Builder.getInt(Value);
2175 // Loop over the components of the offsetof to compute the value.
2176 unsigned n = E->getNumComponents();
2177 llvm::Type* ResultType = ConvertType(E->getType());
2178 llvm::Value* Result = llvm::Constant::getNullValue(ResultType);
2179 QualType CurrentType = E->getTypeSourceInfo()->getType();
2180 for (unsigned i = 0; i != n; ++i) {
2181 OffsetOfNode ON = E->getComponent(i);
2182 llvm::Value *Offset = nullptr;
2183 switch (ON.getKind()) {
2184 case OffsetOfNode::Array: {
2185 // Compute the index
2186 Expr *IdxExpr = E->getIndexExpr(ON.getArrayExprIndex());
2187 llvm::Value* Idx = CGF.EmitScalarExpr(IdxExpr);
2188 bool IdxSigned = IdxExpr->getType()->isSignedIntegerOrEnumerationType();
2189 Idx = Builder.CreateIntCast(Idx, ResultType, IdxSigned, "conv");
2191 // Save the element type
2193 CGF.getContext().getAsArrayType(CurrentType)->getElementType();
2195 // Compute the element size
2196 llvm::Value* ElemSize = llvm::ConstantInt::get(ResultType,
2197 CGF.getContext().getTypeSizeInChars(CurrentType).getQuantity());
2199 // Multiply out to compute the result
2200 Offset = Builder.CreateMul(Idx, ElemSize);
2204 case OffsetOfNode::Field: {
2205 FieldDecl *MemberDecl = ON.getField();
2206 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl();
2207 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD);
2209 // Compute the index of the field in its parent.
2211 // FIXME: It would be nice if we didn't have to loop here!
2212 for (RecordDecl::field_iterator Field = RD->field_begin(),
2213 FieldEnd = RD->field_end();
2214 Field != FieldEnd; ++Field, ++i) {
2215 if (*Field == MemberDecl)
2218 assert(i < RL.getFieldCount() && "offsetof field in wrong type");
2220 // Compute the offset to the field
2221 int64_t OffsetInt = RL.getFieldOffset(i) /
2222 CGF.getContext().getCharWidth();
2223 Offset = llvm::ConstantInt::get(ResultType, OffsetInt);
2225 // Save the element type.
2226 CurrentType = MemberDecl->getType();
2230 case OffsetOfNode::Identifier:
2231 llvm_unreachable("dependent __builtin_offsetof");
2233 case OffsetOfNode::Base: {
2234 if (ON.getBase()->isVirtual()) {
2235 CGF.ErrorUnsupported(E, "virtual base in offsetof");
2239 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl();
2240 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD);
2242 // Save the element type.
2243 CurrentType = ON.getBase()->getType();
2245 // Compute the offset to the base.
2246 const RecordType *BaseRT = CurrentType->getAs<RecordType>();
2247 CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl());
2248 CharUnits OffsetInt = RL.getBaseClassOffset(BaseRD);
2249 Offset = llvm::ConstantInt::get(ResultType, OffsetInt.getQuantity());
2253 Result = Builder.CreateAdd(Result, Offset);
2258 /// VisitUnaryExprOrTypeTraitExpr - Return the size or alignment of the type of
2259 /// argument of the sizeof expression as an integer.
2261 ScalarExprEmitter::VisitUnaryExprOrTypeTraitExpr(
2262 const UnaryExprOrTypeTraitExpr *E) {
2263 QualType TypeToSize = E->getTypeOfArgument();
2264 if (E->getKind() == UETT_SizeOf) {
2265 if (const VariableArrayType *VAT =
2266 CGF.getContext().getAsVariableArrayType(TypeToSize)) {
2267 if (E->isArgumentType()) {
2268 // sizeof(type) - make sure to emit the VLA size.
2269 CGF.EmitVariablyModifiedType(TypeToSize);
2271 // C99 6.5.3.4p2: If the argument is an expression of type
2272 // VLA, it is evaluated.
2273 CGF.EmitIgnoredExpr(E->getArgumentExpr());
2277 llvm::Value *numElts;
2278 std::tie(numElts, eltType) = CGF.getVLASize(VAT);
2280 llvm::Value *size = numElts;
2282 // Scale the number of non-VLA elements by the non-VLA element size.
2283 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
2284 if (!eltSize.isOne())
2285 size = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), numElts);
2289 } else if (E->getKind() == UETT_OpenMPRequiredSimdAlign) {
2292 .toCharUnitsFromBits(CGF.getContext().getOpenMPDefaultSimdAlign(
2293 E->getTypeOfArgument()->getPointeeType()))
2295 return llvm::ConstantInt::get(CGF.SizeTy, Alignment);
2298 // If this isn't sizeof(vla), the result must be constant; use the constant
2299 // folding logic so we don't have to duplicate it here.
2300 return Builder.getInt(E->EvaluateKnownConstInt(CGF.getContext()));
2303 Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) {
2304 Expr *Op = E->getSubExpr();
2305 if (Op->getType()->isAnyComplexType()) {
2306 // If it's an l-value, load through the appropriate subobject l-value.
2307 // Note that we have to ask E because Op might be an l-value that
2308 // this won't work for, e.g. an Obj-C property.
2310 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E),
2311 E->getExprLoc()).getScalarVal();
2313 // Otherwise, calculate and project.
2314 return CGF.EmitComplexExpr(Op, false, true).first;
2320 Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) {
2321 Expr *Op = E->getSubExpr();
2322 if (Op->getType()->isAnyComplexType()) {
2323 // If it's an l-value, load through the appropriate subobject l-value.
2324 // Note that we have to ask E because Op might be an l-value that
2325 // this won't work for, e.g. an Obj-C property.
2326 if (Op->isGLValue())
2327 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E),
2328 E->getExprLoc()).getScalarVal();
2330 // Otherwise, calculate and project.
2331 return CGF.EmitComplexExpr(Op, true, false).second;
2334 // __imag on a scalar returns zero. Emit the subexpr to ensure side
2335 // effects are evaluated, but not the actual value.
2336 if (Op->isGLValue())
2339 CGF.EmitScalarExpr(Op, true);
2340 return llvm::Constant::getNullValue(ConvertType(E->getType()));
2343 //===----------------------------------------------------------------------===//
2345 //===----------------------------------------------------------------------===//
2347 BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) {
2348 TestAndClearIgnoreResultAssign();
2350 Result.LHS = Visit(E->getLHS());
2351 Result.RHS = Visit(E->getRHS());
2352 Result.Ty = E->getType();
2353 Result.Opcode = E->getOpcode();
2354 Result.FPFeatures = E->getFPFeatures();
2359 LValue ScalarExprEmitter::EmitCompoundAssignLValue(
2360 const CompoundAssignOperator *E,
2361 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &),
2363 QualType LHSTy = E->getLHS()->getType();
2366 if (E->getComputationResultType()->isAnyComplexType())
2367 return CGF.EmitScalarCompoundAssignWithComplex(E, Result);
2369 // Emit the RHS first. __block variables need to have the rhs evaluated
2370 // first, plus this should improve codegen a little.
2371 OpInfo.RHS = Visit(E->getRHS());
2372 OpInfo.Ty = E->getComputationResultType();
2373 OpInfo.Opcode = E->getOpcode();
2374 OpInfo.FPFeatures = E->getFPFeatures();
2376 // Load/convert the LHS.
2377 LValue LHSLV = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store);
2379 llvm::PHINode *atomicPHI = nullptr;
2380 if (const AtomicType *atomicTy = LHSTy->getAs<AtomicType>()) {
2381 QualType type = atomicTy->getValueType();
2382 if (!type->isBooleanType() && type->isIntegerType() &&
2383 !(type->isUnsignedIntegerType() &&
2384 CGF.SanOpts.has(SanitizerKind::UnsignedIntegerOverflow)) &&
2385 CGF.getLangOpts().getSignedOverflowBehavior() !=
2386 LangOptions::SOB_Trapping) {
2387 llvm::AtomicRMWInst::BinOp aop = llvm::AtomicRMWInst::BAD_BINOP;
2388 switch (OpInfo.Opcode) {
2389 // We don't have atomicrmw operands for *, %, /, <<, >>
2390 case BO_MulAssign: case BO_DivAssign:
2396 aop = llvm::AtomicRMWInst::Add;
2399 aop = llvm::AtomicRMWInst::Sub;
2402 aop = llvm::AtomicRMWInst::And;
2405 aop = llvm::AtomicRMWInst::Xor;
2408 aop = llvm::AtomicRMWInst::Or;
2411 llvm_unreachable("Invalid compound assignment type");
2413 if (aop != llvm::AtomicRMWInst::BAD_BINOP) {
2414 llvm::Value *amt = CGF.EmitToMemory(
2415 EmitScalarConversion(OpInfo.RHS, E->getRHS()->getType(), LHSTy,
2418 Builder.CreateAtomicRMW(aop, LHSLV.getPointer(), amt,
2419 llvm::AtomicOrdering::SequentiallyConsistent);
2423 // FIXME: For floating point types, we should be saving and restoring the
2424 // floating point environment in the loop.
2425 llvm::BasicBlock *startBB = Builder.GetInsertBlock();
2426 llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn);
2427 OpInfo.LHS = EmitLoadOfLValue(LHSLV, E->getExprLoc());
2428 OpInfo.LHS = CGF.EmitToMemory(OpInfo.LHS, type);
2429 Builder.CreateBr(opBB);
2430 Builder.SetInsertPoint(opBB);
2431 atomicPHI = Builder.CreatePHI(OpInfo.LHS->getType(), 2);
2432 atomicPHI->addIncoming(OpInfo.LHS, startBB);
2433 OpInfo.LHS = atomicPHI;
2436 OpInfo.LHS = EmitLoadOfLValue(LHSLV, E->getExprLoc());
2438 SourceLocation Loc = E->getExprLoc();
2440 EmitScalarConversion(OpInfo.LHS, LHSTy, E->getComputationLHSType(), Loc);
2442 // Expand the binary operator.
2443 Result = (this->*Func)(OpInfo);
2445 // Convert the result back to the LHS type.
2447 EmitScalarConversion(Result, E->getComputationResultType(), LHSTy, Loc);
2450 llvm::BasicBlock *opBB = Builder.GetInsertBlock();
2451 llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn);
2452 auto Pair = CGF.EmitAtomicCompareExchange(
2453 LHSLV, RValue::get(atomicPHI), RValue::get(Result), E->getExprLoc());
2454 llvm::Value *old = CGF.EmitToMemory(Pair.first.getScalarVal(), LHSTy);
2455 llvm::Value *success = Pair.second;
2456 atomicPHI->addIncoming(old, opBB);
2457 Builder.CreateCondBr(success, contBB, opBB);
2458 Builder.SetInsertPoint(contBB);
2462 // Store the result value into the LHS lvalue. Bit-fields are handled
2463 // specially because the result is altered by the store, i.e., [C99 6.5.16p1]
2464 // 'An assignment expression has the value of the left operand after the
2466 if (LHSLV.isBitField())
2467 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, &Result);
2469 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV);
2474 Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E,
2475 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) {
2476 bool Ignore = TestAndClearIgnoreResultAssign();
2478 LValue LHS = EmitCompoundAssignLValue(E, Func, RHS);
2480 // If the result is clearly ignored, return now.
2484 // The result of an assignment in C is the assigned r-value.
2485 if (!CGF.getLangOpts().CPlusPlus)
2488 // If the lvalue is non-volatile, return the computed value of the assignment.
2489 if (!LHS.isVolatileQualified())
2492 // Otherwise, reload the value.
2493 return EmitLoadOfLValue(LHS, E->getExprLoc());
2496 void ScalarExprEmitter::EmitUndefinedBehaviorIntegerDivAndRemCheck(
2497 const BinOpInfo &Ops, llvm::Value *Zero, bool isDiv) {
2498 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 2> Checks;
2500 if (CGF.SanOpts.has(SanitizerKind::IntegerDivideByZero)) {
2501 Checks.push_back(std::make_pair(Builder.CreateICmpNE(Ops.RHS, Zero),
2502 SanitizerKind::IntegerDivideByZero));
2505 const auto *BO = cast<BinaryOperator>(Ops.E);
2506 if (CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow) &&
2507 Ops.Ty->hasSignedIntegerRepresentation() &&
2508 !IsWidenedIntegerOp(CGF.getContext(), BO->getLHS()) &&
2509 Ops.mayHaveIntegerOverflow()) {
2510 llvm::IntegerType *Ty = cast<llvm::IntegerType>(Zero->getType());
2512 llvm::Value *IntMin =
2513 Builder.getInt(llvm::APInt::getSignedMinValue(Ty->getBitWidth()));
2514 llvm::Value *NegOne = llvm::ConstantInt::get(Ty, -1ULL);
2516 llvm::Value *LHSCmp = Builder.CreateICmpNE(Ops.LHS, IntMin);
2517 llvm::Value *RHSCmp = Builder.CreateICmpNE(Ops.RHS, NegOne);
2518 llvm::Value *NotOverflow = Builder.CreateOr(LHSCmp, RHSCmp, "or");
2520 std::make_pair(NotOverflow, SanitizerKind::SignedIntegerOverflow));
2523 if (Checks.size() > 0)
2524 EmitBinOpCheck(Checks, Ops);
2527 Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) {
2529 CodeGenFunction::SanitizerScope SanScope(&CGF);
2530 if ((CGF.SanOpts.has(SanitizerKind::IntegerDivideByZero) ||
2531 CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow)) &&
2532 Ops.Ty->isIntegerType() &&
2533 (Ops.mayHaveIntegerDivisionByZero() || Ops.mayHaveIntegerOverflow())) {
2534 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty));
2535 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, true);
2536 } else if (CGF.SanOpts.has(SanitizerKind::FloatDivideByZero) &&
2537 Ops.Ty->isRealFloatingType() &&
2538 Ops.mayHaveFloatDivisionByZero()) {
2539 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty));
2540 llvm::Value *NonZero = Builder.CreateFCmpUNE(Ops.RHS, Zero);
2541 EmitBinOpCheck(std::make_pair(NonZero, SanitizerKind::FloatDivideByZero),
2546 if (Ops.LHS->getType()->isFPOrFPVectorTy()) {
2547 llvm::Value *Val = Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div");
2548 if (CGF.getLangOpts().OpenCL &&
2549 !CGF.CGM.getCodeGenOpts().CorrectlyRoundedDivSqrt) {
2550 // OpenCL v1.1 s7.4: minimum accuracy of single precision / is 2.5ulp
2551 // OpenCL v1.2 s5.6.4.2: The -cl-fp32-correctly-rounded-divide-sqrt
2552 // build option allows an application to specify that single precision
2553 // floating-point divide (x/y and 1/x) and sqrt used in the program
2554 // source are correctly rounded.
2555 llvm::Type *ValTy = Val->getType();
2556 if (ValTy->isFloatTy() ||
2557 (isa<llvm::VectorType>(ValTy) &&
2558 cast<llvm::VectorType>(ValTy)->getElementType()->isFloatTy()))
2559 CGF.SetFPAccuracy(Val, 2.5);
2563 else if (Ops.Ty->hasUnsignedIntegerRepresentation())
2564 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div");
2566 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div");
2569 Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) {
2570 // Rem in C can't be a floating point type: C99 6.5.5p2.
2571 if ((CGF.SanOpts.has(SanitizerKind::IntegerDivideByZero) ||
2572 CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow)) &&
2573 Ops.Ty->isIntegerType() &&
2574 (Ops.mayHaveIntegerDivisionByZero() || Ops.mayHaveIntegerOverflow())) {
2575 CodeGenFunction::SanitizerScope SanScope(&CGF);
2576 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty));
2577 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, false);
2580 if (Ops.Ty->hasUnsignedIntegerRepresentation())
2581 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem");
2583 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem");
2586 Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) {
2590 bool isSigned = Ops.Ty->isSignedIntegerOrEnumerationType();
2591 switch (Ops.Opcode) {
2595 IID = isSigned ? llvm::Intrinsic::sadd_with_overflow :
2596 llvm::Intrinsic::uadd_with_overflow;
2601 IID = isSigned ? llvm::Intrinsic::ssub_with_overflow :
2602 llvm::Intrinsic::usub_with_overflow;
2607 IID = isSigned ? llvm::Intrinsic::smul_with_overflow :
2608 llvm::Intrinsic::umul_with_overflow;
2611 llvm_unreachable("Unsupported operation for overflow detection");
2617 CodeGenFunction::SanitizerScope SanScope(&CGF);
2618 llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty);
2620 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, opTy);
2622 Value *resultAndOverflow = Builder.CreateCall(intrinsic, {Ops.LHS, Ops.RHS});
2623 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0);
2624 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1);
2626 // Handle overflow with llvm.trap if no custom handler has been specified.
2627 const std::string *handlerName =
2628 &CGF.getLangOpts().OverflowHandler;
2629 if (handlerName->empty()) {
2630 // If the signed-integer-overflow sanitizer is enabled, emit a call to its
2631 // runtime. Otherwise, this is a -ftrapv check, so just emit a trap.
2632 if (!isSigned || CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow)) {
2633 llvm::Value *NotOverflow = Builder.CreateNot(overflow);
2634 SanitizerMask Kind = isSigned ? SanitizerKind::SignedIntegerOverflow
2635 : SanitizerKind::UnsignedIntegerOverflow;
2636 EmitBinOpCheck(std::make_pair(NotOverflow, Kind), Ops);
2638 CGF.EmitTrapCheck(Builder.CreateNot(overflow));
2642 // Branch in case of overflow.
2643 llvm::BasicBlock *initialBB = Builder.GetInsertBlock();
2644 llvm::BasicBlock *continueBB =
2645 CGF.createBasicBlock("nooverflow", CGF.CurFn, initialBB->getNextNode());
2646 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn);
2648 Builder.CreateCondBr(overflow, overflowBB, continueBB);
2650 // If an overflow handler is set, then we want to call it and then use its
2651 // result, if it returns.
2652 Builder.SetInsertPoint(overflowBB);
2654 // Get the overflow handler.
2655 llvm::Type *Int8Ty = CGF.Int8Ty;
2656 llvm::Type *argTypes[] = { CGF.Int64Ty, CGF.Int64Ty, Int8Ty, Int8Ty };
2657 llvm::FunctionType *handlerTy =
2658 llvm::FunctionType::get(CGF.Int64Ty, argTypes, true);
2659 llvm::Value *handler = CGF.CGM.CreateRuntimeFunction(handlerTy, *handlerName);
2661 // Sign extend the args to 64-bit, so that we can use the same handler for
2662 // all types of overflow.
2663 llvm::Value *lhs = Builder.CreateSExt(Ops.LHS, CGF.Int64Ty);
2664 llvm::Value *rhs = Builder.CreateSExt(Ops.RHS, CGF.Int64Ty);
2666 // Call the handler with the two arguments, the operation, and the size of
2668 llvm::Value *handlerArgs[] = {
2671 Builder.getInt8(OpID),
2672 Builder.getInt8(cast<llvm::IntegerType>(opTy)->getBitWidth())
2674 llvm::Value *handlerResult =
2675 CGF.EmitNounwindRuntimeCall(handler, handlerArgs);
2677 // Truncate the result back to the desired size.
2678 handlerResult = Builder.CreateTrunc(handlerResult, opTy);
2679 Builder.CreateBr(continueBB);
2681 Builder.SetInsertPoint(continueBB);
2682 llvm::PHINode *phi = Builder.CreatePHI(opTy, 2);
2683 phi->addIncoming(result, initialBB);
2684 phi->addIncoming(handlerResult, overflowBB);
2689 /// Emit pointer + index arithmetic.
2690 static Value *emitPointerArithmetic(CodeGenFunction &CGF,
2691 const BinOpInfo &op,
2692 bool isSubtraction) {
2693 // Must have binary (not unary) expr here. Unary pointer
2694 // increment/decrement doesn't use this path.
2695 const BinaryOperator *expr = cast<BinaryOperator>(op.E);
2697 Value *pointer = op.LHS;
2698 Expr *pointerOperand = expr->getLHS();
2699 Value *index = op.RHS;
2700 Expr *indexOperand = expr->getRHS();
2702 // In a subtraction, the LHS is always the pointer.
2703 if (!isSubtraction && !pointer->getType()->isPointerTy()) {
2704 std::swap(pointer, index);
2705 std::swap(pointerOperand, indexOperand);
2708 bool isSigned = indexOperand->getType()->isSignedIntegerOrEnumerationType();
2710 unsigned width = cast<llvm::IntegerType>(index->getType())->getBitWidth();
2711 auto &DL = CGF.CGM.getDataLayout();
2712 auto PtrTy = cast<llvm::PointerType>(pointer->getType());
2714 // Some versions of glibc and gcc use idioms (particularly in their malloc
2715 // routines) that add a pointer-sized integer (known to be a pointer value)
2716 // to a null pointer in order to cast the value back to an integer or as
2717 // part of a pointer alignment algorithm. This is undefined behavior, but
2718 // we'd like to be able to compile programs that use it.
2720 // Normally, we'd generate a GEP with a null-pointer base here in response
2721 // to that code, but it's also UB to dereference a pointer created that
2722 // way. Instead (as an acknowledged hack to tolerate the idiom) we will
2723 // generate a direct cast of the integer value to a pointer.
2725 // The idiom (p = nullptr + N) is not met if any of the following are true:
2727 // The operation is subtraction.
2728 // The index is not pointer-sized.
2729 // The pointer type is not byte-sized.
2731 if (BinaryOperator::isNullPointerArithmeticExtension(CGF.getContext(),
2735 return CGF.Builder.CreateIntToPtr(index, pointer->getType());
2737 if (width != DL.getTypeSizeInBits(PtrTy)) {
2738 // Zero-extend or sign-extend the pointer value according to
2739 // whether the index is signed or not.
2740 index = CGF.Builder.CreateIntCast(index, DL.getIntPtrType(PtrTy), isSigned,
2744 // If this is subtraction, negate the index.
2746 index = CGF.Builder.CreateNeg(index, "idx.neg");
2748 if (CGF.SanOpts.has(SanitizerKind::ArrayBounds))
2749 CGF.EmitBoundsCheck(op.E, pointerOperand, index, indexOperand->getType(),
2750 /*Accessed*/ false);
2752 const PointerType *pointerType
2753 = pointerOperand->getType()->getAs<PointerType>();
2755 QualType objectType = pointerOperand->getType()
2756 ->castAs<ObjCObjectPointerType>()
2758 llvm::Value *objectSize
2759 = CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(objectType));
2761 index = CGF.Builder.CreateMul(index, objectSize);
2763 Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy);
2764 result = CGF.Builder.CreateGEP(result, index, "add.ptr");
2765 return CGF.Builder.CreateBitCast(result, pointer->getType());
2768 QualType elementType = pointerType->getPointeeType();
2769 if (const VariableArrayType *vla
2770 = CGF.getContext().getAsVariableArrayType(elementType)) {
2771 // The element count here is the total number of non-VLA elements.
2772 llvm::Value *numElements = CGF.getVLASize(vla).first;
2774 // Effectively, the multiply by the VLA size is part of the GEP.
2775 // GEP indexes are signed, and scaling an index isn't permitted to
2776 // signed-overflow, so we use the same semantics for our explicit
2777 // multiply. We suppress this if overflow is not undefined behavior.
2778 if (CGF.getLangOpts().isSignedOverflowDefined()) {
2779 index = CGF.Builder.CreateMul(index, numElements, "vla.index");
2780 pointer = CGF.Builder.CreateGEP(pointer, index, "add.ptr");
2782 index = CGF.Builder.CreateNSWMul(index, numElements, "vla.index");
2784 CGF.EmitCheckedInBoundsGEP(pointer, index, isSigned, isSubtraction,
2785 op.E->getExprLoc(), "add.ptr");
2790 // Explicitly handle GNU void* and function pointer arithmetic extensions. The
2791 // GNU void* casts amount to no-ops since our void* type is i8*, but this is
2793 if (elementType->isVoidType() || elementType->isFunctionType()) {
2794 Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy);
2795 result = CGF.Builder.CreateGEP(result, index, "add.ptr");
2796 return CGF.Builder.CreateBitCast(result, pointer->getType());
2799 if (CGF.getLangOpts().isSignedOverflowDefined())
2800 return CGF.Builder.CreateGEP(pointer, index, "add.ptr");
2802 return CGF.EmitCheckedInBoundsGEP(pointer, index, isSigned, isSubtraction,
2803 op.E->getExprLoc(), "add.ptr");
2806 // Construct an fmuladd intrinsic to represent a fused mul-add of MulOp and
2807 // Addend. Use negMul and negAdd to negate the first operand of the Mul or
2808 // the add operand respectively. This allows fmuladd to represent a*b-c, or
2809 // c-a*b. Patterns in LLVM should catch the negated forms and translate them to
2810 // efficient operations.
2811 static Value* buildFMulAdd(llvm::BinaryOperator *MulOp, Value *Addend,
2812 const CodeGenFunction &CGF, CGBuilderTy &Builder,
2813 bool negMul, bool negAdd) {
2814 assert(!(negMul && negAdd) && "Only one of negMul and negAdd should be set.");
2816 Value *MulOp0 = MulOp->getOperand(0);
2817 Value *MulOp1 = MulOp->getOperand(1);
2821 llvm::ConstantFP::getZeroValueForNegation(MulOp0->getType()), MulOp0,
2823 } else if (negAdd) {
2826 llvm::ConstantFP::getZeroValueForNegation(Addend->getType()), Addend,
2830 Value *FMulAdd = Builder.CreateCall(
2831 CGF.CGM.getIntrinsic(llvm::Intrinsic::fmuladd, Addend->getType()),
2832 {MulOp0, MulOp1, Addend});
2833 MulOp->eraseFromParent();
2838 // Check whether it would be legal to emit an fmuladd intrinsic call to
2839 // represent op and if so, build the fmuladd.
2841 // Checks that (a) the operation is fusable, and (b) -ffp-contract=on.
2842 // Does NOT check the type of the operation - it's assumed that this function
2843 // will be called from contexts where it's known that the type is contractable.
2844 static Value* tryEmitFMulAdd(const BinOpInfo &op,
2845 const CodeGenFunction &CGF, CGBuilderTy &Builder,
2848 assert((op.Opcode == BO_Add || op.Opcode == BO_AddAssign ||
2849 op.Opcode == BO_Sub || op.Opcode == BO_SubAssign) &&
2850 "Only fadd/fsub can be the root of an fmuladd.");
2852 // Check whether this op is marked as fusable.
2853 if (!op.FPFeatures.allowFPContractWithinStatement())
2856 // We have a potentially fusable op. Look for a mul on one of the operands.
2857 // Also, make sure that the mul result isn't used directly. In that case,
2858 // there's no point creating a muladd operation.
2859 if (auto *LHSBinOp = dyn_cast<llvm::BinaryOperator>(op.LHS)) {
2860 if (LHSBinOp->getOpcode() == llvm::Instruction::FMul &&
2861 LHSBinOp->use_empty())
2862 return buildFMulAdd(LHSBinOp, op.RHS, CGF, Builder, false, isSub);
2864 if (auto *RHSBinOp = dyn_cast<llvm::BinaryOperator>(op.RHS)) {
2865 if (RHSBinOp->getOpcode() == llvm::Instruction::FMul &&
2866 RHSBinOp->use_empty())
2867 return buildFMulAdd(RHSBinOp, op.LHS, CGF, Builder, isSub, false);
2873 Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &op) {
2874 if (op.LHS->getType()->isPointerTy() ||
2875 op.RHS->getType()->isPointerTy())
2876 return emitPointerArithmetic(CGF, op, CodeGenFunction::NotSubtraction);
2878 if (op.Ty->isSignedIntegerOrEnumerationType()) {
2879 switch (CGF.getLangOpts().getSignedOverflowBehavior()) {
2880 case LangOptions::SOB_Defined:
2881 return Builder.CreateAdd(op.LHS, op.RHS, "add");
2882 case LangOptions::SOB_Undefined:
2883 if (!CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow))
2884 return Builder.CreateNSWAdd(op.LHS, op.RHS, "add");
2886 case LangOptions::SOB_Trapping:
2887 if (CanElideOverflowCheck(CGF.getContext(), op))
2888 return Builder.CreateNSWAdd(op.LHS, op.RHS, "add");
2889 return EmitOverflowCheckedBinOp(op);
2893 if (op.Ty->isUnsignedIntegerType() &&
2894 CGF.SanOpts.has(SanitizerKind::UnsignedIntegerOverflow) &&
2895 !CanElideOverflowCheck(CGF.getContext(), op))
2896 return EmitOverflowCheckedBinOp(op);
2898 if (op.LHS->getType()->isFPOrFPVectorTy()) {
2899 // Try to form an fmuladd.
2900 if (Value *FMulAdd = tryEmitFMulAdd(op, CGF, Builder))
2903 Value *V = Builder.CreateFAdd(op.LHS, op.RHS, "add");
2904 return propagateFMFlags(V, op);
2907 return Builder.CreateAdd(op.LHS, op.RHS, "add");
2910 Value *ScalarExprEmitter::EmitSub(const BinOpInfo &op) {
2911 // The LHS is always a pointer if either side is.
2912 if (!op.LHS->getType()->isPointerTy()) {
2913 if (op.Ty->isSignedIntegerOrEnumerationType()) {
2914 switch (CGF.getLangOpts().getSignedOverflowBehavior()) {
2915 case LangOptions::SOB_Defined:
2916 return Builder.CreateSub(op.LHS, op.RHS, "sub");
2917 case LangOptions::SOB_Undefined:
2918 if (!CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow))
2919 return Builder.CreateNSWSub(op.LHS, op.RHS, "sub");
2921 case LangOptions::SOB_Trapping:
2922 if (CanElideOverflowCheck(CGF.getContext(), op))
2923 return Builder.CreateNSWSub(op.LHS, op.RHS, "sub");
2924 return EmitOverflowCheckedBinOp(op);
2928 if (op.Ty->isUnsignedIntegerType() &&
2929 CGF.SanOpts.has(SanitizerKind::UnsignedIntegerOverflow) &&
2930 !CanElideOverflowCheck(CGF.getContext(), op))
2931 return EmitOverflowCheckedBinOp(op);
2933 if (op.LHS->getType()->isFPOrFPVectorTy()) {
2934 // Try to form an fmuladd.
2935 if (Value *FMulAdd = tryEmitFMulAdd(op, CGF, Builder, true))
2937 Value *V = Builder.CreateFSub(op.LHS, op.RHS, "sub");
2938 return propagateFMFlags(V, op);
2941 return Builder.CreateSub(op.LHS, op.RHS, "sub");
2944 // If the RHS is not a pointer, then we have normal pointer
2946 if (!op.RHS->getType()->isPointerTy())
2947 return emitPointerArithmetic(CGF, op, CodeGenFunction::IsSubtraction);
2949 // Otherwise, this is a pointer subtraction.
2951 // Do the raw subtraction part.
2953 = Builder.CreatePtrToInt(op.LHS, CGF.PtrDiffTy, "sub.ptr.lhs.cast");
2955 = Builder.CreatePtrToInt(op.RHS, CGF.PtrDiffTy, "sub.ptr.rhs.cast");
2956 Value *diffInChars = Builder.CreateSub(LHS, RHS, "sub.ptr.sub");
2958 // Okay, figure out the element size.
2959 const BinaryOperator *expr = cast<BinaryOperator>(op.E);
2960 QualType elementType = expr->getLHS()->getType()->getPointeeType();
2962 llvm::Value *divisor = nullptr;
2964 // For a variable-length array, this is going to be non-constant.
2965 if (const VariableArrayType *vla
2966 = CGF.getContext().getAsVariableArrayType(elementType)) {
2967 llvm::Value *numElements;
2968 std::tie(numElements, elementType) = CGF.getVLASize(vla);
2970 divisor = numElements;
2972 // Scale the number of non-VLA elements by the non-VLA element size.
2973 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(elementType);
2974 if (!eltSize.isOne())
2975 divisor = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), divisor);
2977 // For everything elese, we can just compute it, safe in the
2978 // assumption that Sema won't let anything through that we can't
2979 // safely compute the size of.
2981 CharUnits elementSize;
2982 // Handle GCC extension for pointer arithmetic on void* and
2983 // function pointer types.
2984 if (elementType->isVoidType() || elementType->isFunctionType())
2985 elementSize = CharUnits::One();
2987 elementSize = CGF.getContext().getTypeSizeInChars(elementType);
2989 // Don't even emit the divide for element size of 1.
2990 if (elementSize.isOne())
2993 divisor = CGF.CGM.getSize(elementSize);
2996 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since
2997 // pointer difference in C is only defined in the case where both operands
2998 // are pointing to elements of an array.
2999 return Builder.CreateExactSDiv(diffInChars, divisor, "sub.ptr.div");
3002 Value *ScalarExprEmitter::GetWidthMinusOneValue(Value* LHS,Value* RHS) {
3003 llvm::IntegerType *Ty;
3004 if (llvm::VectorType *VT = dyn_cast<llvm::VectorType>(LHS->getType()))
3005 Ty = cast<llvm::IntegerType>(VT->getElementType());
3007 Ty = cast<llvm::IntegerType>(LHS->getType());
3008 return llvm::ConstantInt::get(RHS->getType(), Ty->getBitWidth() - 1);
3011 Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) {
3012 // LLVM requires the LHS and RHS to be the same type: promote or truncate the
3013 // RHS to the same size as the LHS.
3014 Value *RHS = Ops.RHS;
3015 if (Ops.LHS->getType() != RHS->getType())
3016 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom");
3018 bool SanitizeBase = CGF.SanOpts.has(SanitizerKind::ShiftBase) &&
3019 Ops.Ty->hasSignedIntegerRepresentation() &&
3020 !CGF.getLangOpts().isSignedOverflowDefined();
3021 bool SanitizeExponent = CGF.SanOpts.has(SanitizerKind::ShiftExponent);
3022 // OpenCL 6.3j: shift values are effectively % word size of LHS.
3023 if (CGF.getLangOpts().OpenCL)
3025 Builder.CreateAnd(RHS, GetWidthMinusOneValue(Ops.LHS, RHS), "shl.mask");
3026 else if ((SanitizeBase || SanitizeExponent) &&
3027 isa<llvm::IntegerType>(Ops.LHS->getType())) {
3028 CodeGenFunction::SanitizerScope SanScope(&CGF);
3029 SmallVector<std::pair<Value *, SanitizerMask>, 2> Checks;
3030 llvm::Value *WidthMinusOne = GetWidthMinusOneValue(Ops.LHS, Ops.RHS);
3031 llvm::Value *ValidExponent = Builder.CreateICmpULE(Ops.RHS, WidthMinusOne);
3033 if (SanitizeExponent) {
3035 std::make_pair(ValidExponent, SanitizerKind::ShiftExponent));
3039 // Check whether we are shifting any non-zero bits off the top of the
3040 // integer. We only emit this check if exponent is valid - otherwise
3041 // instructions below will have undefined behavior themselves.
3042 llvm::BasicBlock *Orig = Builder.GetInsertBlock();
3043 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont");
3044 llvm::BasicBlock *CheckShiftBase = CGF.createBasicBlock("check");
3045 Builder.CreateCondBr(ValidExponent, CheckShiftBase, Cont);
3046 llvm::Value *PromotedWidthMinusOne =
3047 (RHS == Ops.RHS) ? WidthMinusOne
3048 : GetWidthMinusOneValue(Ops.LHS, RHS);
3049 CGF.EmitBlock(CheckShiftBase);
3050 llvm::Value *BitsShiftedOff = Builder.CreateLShr(
3051 Ops.LHS, Builder.CreateSub(PromotedWidthMinusOne, RHS, "shl.zeros",
3052 /*NUW*/ true, /*NSW*/ true),
3054 if (CGF.getLangOpts().CPlusPlus) {
3055 // In C99, we are not permitted to shift a 1 bit into the sign bit.
3056 // Under C++11's rules, shifting a 1 bit into the sign bit is
3057 // OK, but shifting a 1 bit out of it is not. (C89 and C++03 don't
3058 // define signed left shifts, so we use the C99 and C++11 rules there).
3059 llvm::Value *One = llvm::ConstantInt::get(BitsShiftedOff->getType(), 1);
3060 BitsShiftedOff = Builder.CreateLShr(BitsShiftedOff, One);
3062 llvm::Value *Zero = llvm::ConstantInt::get(BitsShiftedOff->getType(), 0);
3063 llvm::Value *ValidBase = Builder.CreateICmpEQ(BitsShiftedOff, Zero);
3064 CGF.EmitBlock(Cont);
3065 llvm::PHINode *BaseCheck = Builder.CreatePHI(ValidBase->getType(), 2);
3066 BaseCheck->addIncoming(Builder.getTrue(), Orig);
3067 BaseCheck->addIncoming(ValidBase, CheckShiftBase);
3068 Checks.push_back(std::make_pair(BaseCheck, SanitizerKind::ShiftBase));
3071 assert(!Checks.empty());
3072 EmitBinOpCheck(Checks, Ops);
3075 return Builder.CreateShl(Ops.LHS, RHS, "shl");
3078 Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) {
3079 // LLVM requires the LHS and RHS to be the same type: promote or truncate the
3080 // RHS to the same size as the LHS.
3081 Value *RHS = Ops.RHS;
3082 if (Ops.LHS->getType() != RHS->getType())
3083 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom");
3085 // OpenCL 6.3j: shift values are effectively % word size of LHS.
3086 if (CGF.getLangOpts().OpenCL)
3088 Builder.CreateAnd(RHS, GetWidthMinusOneValue(Ops.LHS, RHS), "shr.mask");
3089 else if (CGF.SanOpts.has(SanitizerKind::ShiftExponent) &&
3090 isa<llvm::IntegerType>(Ops.LHS->getType())) {
3091 CodeGenFunction::SanitizerScope SanScope(&CGF);
3092 llvm::Value *Valid =
3093 Builder.CreateICmpULE(RHS, GetWidthMinusOneValue(Ops.LHS, RHS));
3094 EmitBinOpCheck(std::make_pair(Valid, SanitizerKind::ShiftExponent), Ops);
3097 if (Ops.Ty->hasUnsignedIntegerRepresentation())
3098 return Builder.CreateLShr(Ops.LHS, RHS, "shr");
3099 return Builder.CreateAShr(Ops.LHS, RHS, "shr");
3102 enum IntrinsicType { VCMPEQ, VCMPGT };
3103 // return corresponding comparison intrinsic for given vector type
3104 static llvm::Intrinsic::ID GetIntrinsic(IntrinsicType IT,
3105 BuiltinType::Kind ElemKind) {
3107 default: llvm_unreachable("unexpected element type");
3108 case BuiltinType::Char_U:
3109 case BuiltinType::UChar:
3110 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p :
3111 llvm::Intrinsic::ppc_altivec_vcmpgtub_p;
3112 case BuiltinType::Char_S:
3113 case BuiltinType::SChar:
3114 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p :
3115 llvm::Intrinsic::ppc_altivec_vcmpgtsb_p;
3116 case BuiltinType::UShort:
3117 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p :
3118 llvm::Intrinsic::ppc_altivec_vcmpgtuh_p;
3119 case BuiltinType::Short:
3120 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p :
3121 llvm::Intrinsic::ppc_altivec_vcmpgtsh_p;
3122 case BuiltinType::UInt:
3123 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p :
3124 llvm::Intrinsic::ppc_altivec_vcmpgtuw_p;
3125 case BuiltinType::Int:
3126 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p :
3127 llvm::Intrinsic::ppc_altivec_vcmpgtsw_p;
3128 case BuiltinType::ULong:
3129 case BuiltinType::ULongLong:
3130 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequd_p :
3131 llvm::Intrinsic::ppc_altivec_vcmpgtud_p;
3132 case BuiltinType::Long:
3133 case BuiltinType::LongLong:
3134 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequd_p :
3135 llvm::Intrinsic::ppc_altivec_vcmpgtsd_p;
3136 case BuiltinType::Float:
3137 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpeqfp_p :
3138 llvm::Intrinsic::ppc_altivec_vcmpgtfp_p;
3139 case BuiltinType::Double:
3140 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_vsx_xvcmpeqdp_p :
3141 llvm::Intrinsic::ppc_vsx_xvcmpgtdp_p;
3145 Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,
3146 llvm::CmpInst::Predicate UICmpOpc,
3147 llvm::CmpInst::Predicate SICmpOpc,
3148 llvm::CmpInst::Predicate FCmpOpc) {
3149 TestAndClearIgnoreResultAssign();
3151 QualType LHSTy = E->getLHS()->getType();
3152 QualType RHSTy = E->getRHS()->getType();
3153 if (const MemberPointerType *MPT = LHSTy->getAs<MemberPointerType>()) {
3154 assert(E->getOpcode() == BO_EQ ||
3155 E->getOpcode() == BO_NE);
3156 Value *LHS = CGF.EmitScalarExpr(E->getLHS());
3157 Value *RHS = CGF.EmitScalarExpr(E->getRHS());
3158 Result = CGF.CGM.getCXXABI().EmitMemberPointerComparison(
3159 CGF, LHS, RHS, MPT, E->getOpcode() == BO_NE);
3160 } else if (!LHSTy->isAnyComplexType() && !RHSTy->isAnyComplexType()) {
3161 Value *LHS = Visit(E->getLHS());
3162 Value *RHS = Visit(E->getRHS());
3164 // If AltiVec, the comparison results in a numeric type, so we use
3165 // intrinsics comparing vectors and giving 0 or 1 as a result
3166 if (LHSTy->isVectorType() && !E->getType()->isVectorType()) {
3167 // constants for mapping CR6 register bits to predicate result
3168 enum { CR6_EQ=0, CR6_EQ_REV, CR6_LT, CR6_LT_REV } CR6;
3170 llvm::Intrinsic::ID ID = llvm::Intrinsic::not_intrinsic;
3172 // in several cases vector arguments order will be reversed
3173 Value *FirstVecArg = LHS,
3174 *SecondVecArg = RHS;
3176 QualType ElTy = LHSTy->getAs<VectorType>()->getElementType();
3177 const BuiltinType *BTy = ElTy->getAs<BuiltinType>();
3178 BuiltinType::Kind ElementKind = BTy->getKind();
3180 switch(E->getOpcode()) {
3181 default: llvm_unreachable("is not a comparison operation");
3184 ID = GetIntrinsic(VCMPEQ, ElementKind);
3188 ID = GetIntrinsic(VCMPEQ, ElementKind);
3192 ID = GetIntrinsic(VCMPGT, ElementKind);
3193 std::swap(FirstVecArg, SecondVecArg);
3197 ID = GetIntrinsic(VCMPGT, ElementKind);
3200 if (ElementKind == BuiltinType::Float) {
3202 ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p;
3203 std::swap(FirstVecArg, SecondVecArg);
3207 ID = GetIntrinsic(VCMPGT, ElementKind);
3211 if (ElementKind == BuiltinType::Float) {
3213 ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p;
3217 ID = GetIntrinsic(VCMPGT, ElementKind);
3218 std::swap(FirstVecArg, SecondVecArg);
3223 Value *CR6Param = Builder.getInt32(CR6);
3224 llvm::Function *F = CGF.CGM.getIntrinsic(ID);
3225 Result = Builder.CreateCall(F, {CR6Param, FirstVecArg, SecondVecArg});
3227 // The result type of intrinsic may not be same as E->getType().
3228 // If E->getType() is not BoolTy, EmitScalarConversion will do the
3229 // conversion work. If E->getType() is BoolTy, EmitScalarConversion will
3230 // do nothing, if ResultTy is not i1 at the same time, it will cause
3232 llvm::IntegerType *ResultTy = cast<llvm::IntegerType>(Result->getType());
3233 if (ResultTy->getBitWidth() > 1 &&
3234 E->getType() == CGF.getContext().BoolTy)
3235 Result = Builder.CreateTrunc(Result, Builder.getInt1Ty());
3236 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType(),
3240 if (LHS->getType()->isFPOrFPVectorTy()) {
3241 Result = Builder.CreateFCmp(FCmpOpc, LHS, RHS, "cmp");
3242 } else if (LHSTy->hasSignedIntegerRepresentation()) {
3243 Result = Builder.CreateICmp(SICmpOpc, LHS, RHS, "cmp");
3245 // Unsigned integers and pointers.
3246 Result = Builder.CreateICmp(UICmpOpc, LHS, RHS, "cmp");
3249 // If this is a vector comparison, sign extend the result to the appropriate
3250 // vector integer type and return it (don't convert to bool).
3251 if (LHSTy->isVectorType())
3252 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext");
3255 // Complex Comparison: can only be an equality comparison.
3256 CodeGenFunction::ComplexPairTy LHS, RHS;
3258 if (auto *CTy = LHSTy->getAs<ComplexType>()) {
3259 LHS = CGF.EmitComplexExpr(E->getLHS());
3260 CETy = CTy->getElementType();
3262 LHS.first = Visit(E->getLHS());
3263 LHS.second = llvm::Constant::getNullValue(LHS.first->getType());
3266 if (auto *CTy = RHSTy->getAs<ComplexType>()) {
3267 RHS = CGF.EmitComplexExpr(E->getRHS());
3268 assert(CGF.getContext().hasSameUnqualifiedType(CETy,
3269 CTy->getElementType()) &&
3270 "The element types must always match.");
3273 RHS.first = Visit(E->getRHS());
3274 RHS.second = llvm::Constant::getNullValue(RHS.first->getType());
3275 assert(CGF.getContext().hasSameUnqualifiedType(CETy, RHSTy) &&
3276 "The element types must always match.");
3279 Value *ResultR, *ResultI;
3280 if (CETy->isRealFloatingType()) {
3281 ResultR = Builder.CreateFCmp(FCmpOpc, LHS.first, RHS.first, "cmp.r");
3282 ResultI = Builder.CreateFCmp(FCmpOpc, LHS.second, RHS.second, "cmp.i");
3284 // Complex comparisons can only be equality comparisons. As such, signed
3285 // and unsigned opcodes are the same.
3286 ResultR = Builder.CreateICmp(UICmpOpc, LHS.first, RHS.first, "cmp.r");
3287 ResultI = Builder.CreateICmp(UICmpOpc, LHS.second, RHS.second, "cmp.i");
3290 if (E->getOpcode() == BO_EQ) {
3291 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri");
3293 assert(E->getOpcode() == BO_NE &&
3294 "Complex comparison other than == or != ?");
3295 Result = Builder.CreateOr(ResultR, ResultI, "or.ri");
3299 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType(),
3303 Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) {
3304 bool Ignore = TestAndClearIgnoreResultAssign();
3309 switch (E->getLHS()->getType().getObjCLifetime()) {
3310 case Qualifiers::OCL_Strong:
3311 std::tie(LHS, RHS) = CGF.EmitARCStoreStrong(E, Ignore);
3314 case Qualifiers::OCL_Autoreleasing:
3315 std::tie(LHS, RHS) = CGF.EmitARCStoreAutoreleasing(E);
3318 case Qualifiers::OCL_ExplicitNone:
3319 std::tie(LHS, RHS) = CGF.EmitARCStoreUnsafeUnretained(E, Ignore);
3322 case Qualifiers::OCL_Weak:
3323 RHS = Visit(E->getRHS());
3324 LHS = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store);
3325 RHS = CGF.EmitARCStoreWeak(LHS.getAddress(), RHS, Ignore);
3328 case Qualifiers::OCL_None:
3329 // __block variables need to have the rhs evaluated first, plus
3330 // this should improve codegen just a little.
3331 RHS = Visit(E->getRHS());
3332 LHS = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store);
3334 // Store the value into the LHS. Bit-fields are handled specially
3335 // because the result is altered by the store, i.e., [C99 6.5.16p1]
3336 // 'An assignment expression has the value of the left operand after
3337 // the assignment...'.
3338 if (LHS.isBitField()) {
3339 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, &RHS);
3341 CGF.EmitNullabilityCheck(LHS, RHS, E->getExprLoc());
3342 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS);
3346 // If the result is clearly ignored, return now.
3350 // The result of an assignment in C is the assigned r-value.
3351 if (!CGF.getLangOpts().CPlusPlus)
3354 // If the lvalue is non-volatile, return the computed value of the assignment.
3355 if (!LHS.isVolatileQualified())
3358 // Otherwise, reload the value.
3359 return EmitLoadOfLValue(LHS, E->getExprLoc());
3362 Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) {
3363 // Perform vector logical and on comparisons with zero vectors.
3364 if (E->getType()->isVectorType()) {
3365 CGF.incrementProfileCounter(E);
3367 Value *LHS = Visit(E->getLHS());
3368 Value *RHS = Visit(E->getRHS());
3369 Value *Zero = llvm::ConstantAggregateZero::get(LHS->getType());
3370 if (LHS->getType()->isFPOrFPVectorTy()) {
3371 LHS = Builder.CreateFCmp(llvm::CmpInst::FCMP_UNE, LHS, Zero, "cmp");
3372 RHS = Builder.CreateFCmp(llvm::CmpInst::FCMP_UNE, RHS, Zero, "cmp");
3374 LHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, LHS, Zero, "cmp");
3375 RHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, RHS, Zero, "cmp");
3377 Value *And = Builder.CreateAnd(LHS, RHS);
3378 return Builder.CreateSExt(And, ConvertType(E->getType()), "sext");
3381 llvm::Type *ResTy = ConvertType(E->getType());
3383 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0.
3384 // If we have 1 && X, just emit X without inserting the control flow.
3386 if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) {
3387 if (LHSCondVal) { // If we have 1 && X, just emit X.
3388 CGF.incrementProfileCounter(E);
3390 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
3391 // ZExt result to int or bool.
3392 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext");
3395 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false.
3396 if (!CGF.ContainsLabel(E->getRHS()))
3397 return llvm::Constant::getNullValue(ResTy);
3400 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end");
3401 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs");
3403 CodeGenFunction::ConditionalEvaluation eval(CGF);
3405 // Branch on the LHS first. If it is false, go to the failure (cont) block.
3406 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock,
3407 CGF.getProfileCount(E->getRHS()));
3409 // Any edges into the ContBlock are now from an (indeterminate number of)
3410 // edges from this first condition. All of these values will be false. Start
3411 // setting up the PHI node in the Cont Block for this.
3412 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2,
3414 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock);
3416 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI);
3419 CGF.EmitBlock(RHSBlock);
3420 CGF.incrementProfileCounter(E);
3421 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
3424 // Reaquire the RHS block, as there may be subblocks inserted.
3425 RHSBlock = Builder.GetInsertBlock();
3427 // Emit an unconditional branch from this block to ContBlock.
3429 // There is no need to emit line number for unconditional branch.
3430 auto NL = ApplyDebugLocation::CreateEmpty(CGF);
3431 CGF.EmitBlock(ContBlock);
3433 // Insert an entry into the phi node for the edge with the value of RHSCond.
3434 PN->addIncoming(RHSCond, RHSBlock);
3436 // ZExt result to int.
3437 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext");
3440 Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) {
3441 // Perform vector logical or on comparisons with zero vectors.
3442 if (E->getType()->isVectorType()) {
3443 CGF.incrementProfileCounter(E);
3445 Value *LHS = Visit(E->getLHS());
3446 Value *RHS = Visit(E->getRHS());
3447 Value *Zero = llvm::ConstantAggregateZero::get(LHS->getType());
3448 if (LHS->getType()->isFPOrFPVectorTy()) {
3449 LHS = Builder.CreateFCmp(llvm::CmpInst::FCMP_UNE, LHS, Zero, "cmp");
3450 RHS = Builder.CreateFCmp(llvm::CmpInst::FCMP_UNE, RHS, Zero, "cmp");
3452 LHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, LHS, Zero, "cmp");
3453 RHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, RHS, Zero, "cmp");
3455 Value *Or = Builder.CreateOr(LHS, RHS);
3456 return Builder.CreateSExt(Or, ConvertType(E->getType()), "sext");
3459 llvm::Type *ResTy = ConvertType(E->getType());
3461 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1.
3462 // If we have 0 || X, just emit X without inserting the control flow.
3464 if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) {
3465 if (!LHSCondVal) { // If we have 0 || X, just emit X.
3466 CGF.incrementProfileCounter(E);
3468 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
3469 // ZExt result to int or bool.
3470 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext");
3473 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true.
3474 if (!CGF.ContainsLabel(E->getRHS()))
3475 return llvm::ConstantInt::get(ResTy, 1);
3478 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end");
3479 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs");
3481 CodeGenFunction::ConditionalEvaluation eval(CGF);
3483 // Branch on the LHS first. If it is true, go to the success (cont) block.
3484 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock,
3485 CGF.getCurrentProfileCount() -
3486 CGF.getProfileCount(E->getRHS()));
3488 // Any edges into the ContBlock are now from an (indeterminate number of)
3489 // edges from this first condition. All of these values will be true. Start
3490 // setting up the PHI node in the Cont Block for this.
3491 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2,
3493 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock);
3495 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI);
3499 // Emit the RHS condition as a bool value.
3500 CGF.EmitBlock(RHSBlock);
3501 CGF.incrementProfileCounter(E);
3502 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
3506 // Reaquire the RHS block, as there may be subblocks inserted.
3507 RHSBlock = Builder.GetInsertBlock();
3509 // Emit an unconditional branch from this block to ContBlock. Insert an entry
3510 // into the phi node for the edge with the value of RHSCond.
3511 CGF.EmitBlock(ContBlock);
3512 PN->addIncoming(RHSCond, RHSBlock);
3514 // ZExt result to int.
3515 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext");
3518 Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) {
3519 CGF.EmitIgnoredExpr(E->getLHS());
3520 CGF.EnsureInsertPoint();
3521 return Visit(E->getRHS());
3524 //===----------------------------------------------------------------------===//
3526 //===----------------------------------------------------------------------===//
3528 /// isCheapEnoughToEvaluateUnconditionally - Return true if the specified
3529 /// expression is cheap enough and side-effect-free enough to evaluate
3530 /// unconditionally instead of conditionally. This is used to convert control
3531 /// flow into selects in some cases.
3532 static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E,
3533 CodeGenFunction &CGF) {
3534 // Anything that is an integer or floating point constant is fine.
3535 return E->IgnoreParens()->isEvaluatable(CGF.getContext());
3537 // Even non-volatile automatic variables can't be evaluated unconditionally.
3538 // Referencing a thread_local may cause non-trivial initialization work to
3539 // occur. If we're inside a lambda and one of the variables is from the scope
3540 // outside the lambda, that function may have returned already. Reading its
3541 // locals is a bad idea. Also, these reads may introduce races there didn't
3542 // exist in the source-level program.
3546 Value *ScalarExprEmitter::
3547 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
3548 TestAndClearIgnoreResultAssign();
3550 // Bind the common expression if necessary.
3551 CodeGenFunction::OpaqueValueMapping binding(CGF, E);
3553 Expr *condExpr = E->getCond();
3554 Expr *lhsExpr = E->getTrueExpr();
3555 Expr *rhsExpr = E->getFalseExpr();
3557 // If the condition constant folds and can be elided, try to avoid emitting
3558 // the condition and the dead arm.
3560 if (CGF.ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
3561 Expr *live = lhsExpr, *dead = rhsExpr;
3562 if (!CondExprBool) std::swap(live, dead);
3564 // If the dead side doesn't have labels we need, just emit the Live part.
3565 if (!CGF.ContainsLabel(dead)) {
3567 CGF.incrementProfileCounter(E);
3568 Value *Result = Visit(live);
3570 // If the live part is a throw expression, it acts like it has a void
3571 // type, so evaluating it returns a null Value*. However, a conditional
3572 // with non-void type must return a non-null Value*.
3573 if (!Result && !E->getType()->isVoidType())
3574 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType()));
3580 // OpenCL: If the condition is a vector, we can treat this condition like
3581 // the select function.
3582 if (CGF.getLangOpts().OpenCL
3583 && condExpr->getType()->isVectorType()) {
3584 CGF.incrementProfileCounter(E);
3586 llvm::Value *CondV = CGF.EmitScalarExpr(condExpr);
3587 llvm::Value *LHS = Visit(lhsExpr);
3588 llvm::Value *RHS = Visit(rhsExpr);
3590 llvm::Type *condType = ConvertType(condExpr->getType());
3591 llvm::VectorType *vecTy = cast<llvm::VectorType>(condType);
3593 unsigned numElem = vecTy->getNumElements();
3594 llvm::Type *elemType = vecTy->getElementType();
3596 llvm::Value *zeroVec = llvm::Constant::getNullValue(vecTy);
3597 llvm::Value *TestMSB = Builder.CreateICmpSLT(CondV, zeroVec);
3598 llvm::Value *tmp = Builder.CreateSExt(TestMSB,
3599 llvm::VectorType::get(elemType,
3602 llvm::Value *tmp2 = Builder.CreateNot(tmp);
3604 // Cast float to int to perform ANDs if necessary.
3605 llvm::Value *RHSTmp = RHS;
3606 llvm::Value *LHSTmp = LHS;
3607 bool wasCast = false;
3608 llvm::VectorType *rhsVTy = cast<llvm::VectorType>(RHS->getType());
3609 if (rhsVTy->getElementType()->isFloatingPointTy()) {
3610 RHSTmp = Builder.CreateBitCast(RHS, tmp2->getType());
3611 LHSTmp = Builder.CreateBitCast(LHS, tmp->getType());
3615 llvm::Value *tmp3 = Builder.CreateAnd(RHSTmp, tmp2);
3616 llvm::Value *tmp4 = Builder.CreateAnd(LHSTmp, tmp);
3617 llvm::Value *tmp5 = Builder.CreateOr(tmp3, tmp4, "cond");
3619 tmp5 = Builder.CreateBitCast(tmp5, RHS->getType());
3624 // If this is a really simple expression (like x ? 4 : 5), emit this as a
3625 // select instead of as control flow. We can only do this if it is cheap and
3626 // safe to evaluate the LHS and RHS unconditionally.
3627 if (isCheapEnoughToEvaluateUnconditionally(lhsExpr, CGF) &&
3628 isCheapEnoughToEvaluateUnconditionally(rhsExpr, CGF)) {
3629 llvm::Value *CondV = CGF.EvaluateExprAsBool(condExpr);
3630 llvm::Value *StepV = Builder.CreateZExtOrBitCast(CondV, CGF.Int64Ty);
3632 CGF.incrementProfileCounter(E, StepV);
3634 llvm::Value *LHS = Visit(lhsExpr);
3635 llvm::Value *RHS = Visit(rhsExpr);
3637 // If the conditional has void type, make sure we return a null Value*.
3638 assert(!RHS && "LHS and RHS types must match");
3641 return Builder.CreateSelect(CondV, LHS, RHS, "cond");
3644 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
3645 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
3646 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
3648 CodeGenFunction::ConditionalEvaluation eval(CGF);
3649 CGF.EmitBranchOnBoolExpr(condExpr, LHSBlock, RHSBlock,
3650 CGF.getProfileCount(lhsExpr));
3652 CGF.EmitBlock(LHSBlock);
3653 CGF.incrementProfileCounter(E);
3655 Value *LHS = Visit(lhsExpr);
3658 LHSBlock = Builder.GetInsertBlock();
3659 Builder.CreateBr(ContBlock);
3661 CGF.EmitBlock(RHSBlock);
3663 Value *RHS = Visit(rhsExpr);
3666 RHSBlock = Builder.GetInsertBlock();
3667 CGF.EmitBlock(ContBlock);
3669 // If the LHS or RHS is a throw expression, it will be legitimately null.
3675 // Create a PHI node for the real part.
3676 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), 2, "cond");
3677 PN->addIncoming(LHS, LHSBlock);
3678 PN->addIncoming(RHS, RHSBlock);
3682 Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) {
3683 return Visit(E->getChosenSubExpr());
3686 Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) {
3687 QualType Ty = VE->getType();
3689 if (Ty->isVariablyModifiedType())
3690 CGF.EmitVariablyModifiedType(Ty);
3692 Address ArgValue = Address::invalid();
3693 Address ArgPtr = CGF.EmitVAArg(VE, ArgValue);
3695 llvm::Type *ArgTy = ConvertType(VE->getType());
3697 // If EmitVAArg fails, emit an error.
3698 if (!ArgPtr.isValid()) {
3699 CGF.ErrorUnsupported(VE, "va_arg expression");
3700 return llvm::UndefValue::get(ArgTy);
3703 // FIXME Volatility.
3704 llvm::Value *Val = Builder.CreateLoad(ArgPtr);
3706 // If EmitVAArg promoted the type, we must truncate it.
3707 if (ArgTy != Val->getType()) {
3708 if (ArgTy->isPointerTy() && !Val->getType()->isPointerTy())
3709 Val = Builder.CreateIntToPtr(Val, ArgTy);
3711 Val = Builder.CreateTrunc(Val, ArgTy);
3717 Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *block) {
3718 return CGF.EmitBlockLiteral(block);
3721 // Convert a vec3 to vec4, or vice versa.
3722 static Value *ConvertVec3AndVec4(CGBuilderTy &Builder, CodeGenFunction &CGF,
3723 Value *Src, unsigned NumElementsDst) {
3724 llvm::Value *UnV = llvm::UndefValue::get(Src->getType());
3725 SmallVector<llvm::Constant*, 4> Args;
3726 Args.push_back(Builder.getInt32(0));
3727 Args.push_back(Builder.getInt32(1));
3728 Args.push_back(Builder.getInt32(2));
3729 if (NumElementsDst == 4)
3730 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty));
3731 llvm::Constant *Mask = llvm::ConstantVector::get(Args);
3732 return Builder.CreateShuffleVector(Src, UnV, Mask);
3735 // Create cast instructions for converting LLVM value \p Src to LLVM type \p
3736 // DstTy. \p Src has the same size as \p DstTy. Both are single value types
3737 // but could be scalar or vectors of different lengths, and either can be
3739 // There are 4 cases:
3740 // 1. non-pointer -> non-pointer : needs 1 bitcast
3741 // 2. pointer -> pointer : needs 1 bitcast or addrspacecast
3742 // 3. pointer -> non-pointer
3743 // a) pointer -> intptr_t : needs 1 ptrtoint
3744 // b) pointer -> non-intptr_t : needs 1 ptrtoint then 1 bitcast
3745 // 4. non-pointer -> pointer
3746 // a) intptr_t -> pointer : needs 1 inttoptr
3747 // b) non-intptr_t -> pointer : needs 1 bitcast then 1 inttoptr
3748 // Note: for cases 3b and 4b two casts are required since LLVM casts do not
3749 // allow casting directly between pointer types and non-integer non-pointer
3751 static Value *createCastsForTypeOfSameSize(CGBuilderTy &Builder,
3752 const llvm::DataLayout &DL,
3753 Value *Src, llvm::Type *DstTy,
3754 StringRef Name = "") {
3755 auto SrcTy = Src->getType();
3758 if (!SrcTy->isPointerTy() && !DstTy->isPointerTy())
3759 return Builder.CreateBitCast(Src, DstTy, Name);
3762 if (SrcTy->isPointerTy() && DstTy->isPointerTy())
3763 return Builder.CreatePointerBitCastOrAddrSpaceCast(Src, DstTy, Name);
3766 if (SrcTy->isPointerTy() && !DstTy->isPointerTy()) {
3768 if (!DstTy->isIntegerTy())
3769 Src = Builder.CreatePtrToInt(Src, DL.getIntPtrType(SrcTy));
3771 return Builder.CreateBitOrPointerCast(Src, DstTy, Name);
3775 if (!SrcTy->isIntegerTy())
3776 Src = Builder.CreateBitCast(Src, DL.getIntPtrType(DstTy));
3778 return Builder.CreateIntToPtr(Src, DstTy, Name);
3781 Value *ScalarExprEmitter::VisitAsTypeExpr(AsTypeExpr *E) {
3782 Value *Src = CGF.EmitScalarExpr(E->getSrcExpr());
3783 llvm::Type *DstTy = ConvertType(E->getType());
3785 llvm::Type *SrcTy = Src->getType();
3786 unsigned NumElementsSrc = isa<llvm::VectorType>(SrcTy) ?
3787 cast<llvm::VectorType>(SrcTy)->getNumElements() : 0;
3788 unsigned NumElementsDst = isa<llvm::VectorType>(DstTy) ?
3789 cast<llvm::VectorType>(DstTy)->getNumElements() : 0;
3791 // Going from vec3 to non-vec3 is a special case and requires a shuffle
3792 // vector to get a vec4, then a bitcast if the target type is different.
3793 if (NumElementsSrc == 3 && NumElementsDst != 3) {
3794 Src = ConvertVec3AndVec4(Builder, CGF, Src, 4);
3796 if (!CGF.CGM.getCodeGenOpts().PreserveVec3Type) {
3797 Src = createCastsForTypeOfSameSize(Builder, CGF.CGM.getDataLayout(), Src,
3801 Src->setName("astype");
3805 // Going from non-vec3 to vec3 is a special case and requires a bitcast
3806 // to vec4 if the original type is not vec4, then a shuffle vector to
3808 if (NumElementsSrc != 3 && NumElementsDst == 3) {
3809 if (!CGF.CGM.getCodeGenOpts().PreserveVec3Type) {
3810 auto Vec4Ty = llvm::VectorType::get(DstTy->getVectorElementType(), 4);
3811 Src = createCastsForTypeOfSameSize(Builder, CGF.CGM.getDataLayout(), Src,
3815 Src = ConvertVec3AndVec4(Builder, CGF, Src, 3);
3816 Src->setName("astype");
3820 return Src = createCastsForTypeOfSameSize(Builder, CGF.CGM.getDataLayout(),
3821 Src, DstTy, "astype");
3824 Value *ScalarExprEmitter::VisitAtomicExpr(AtomicExpr *E) {
3825 return CGF.EmitAtomicExpr(E).getScalarVal();
3828 //===----------------------------------------------------------------------===//
3829 // Entry Point into this File
3830 //===----------------------------------------------------------------------===//
3832 /// Emit the computation of the specified expression of scalar type, ignoring
3834 Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) {
3835 assert(E && hasScalarEvaluationKind(E->getType()) &&
3836 "Invalid scalar expression to emit");
3838 return ScalarExprEmitter(*this, IgnoreResultAssign)
3839 .Visit(const_cast<Expr *>(E));
3842 /// Emit a conversion from the specified type to the specified destination type,
3843 /// both of which are LLVM scalar types.
3844 Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy,
3846 SourceLocation Loc) {
3847 assert(hasScalarEvaluationKind(SrcTy) && hasScalarEvaluationKind(DstTy) &&
3848 "Invalid scalar expression to emit");
3849 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy, Loc);
3852 /// Emit a conversion from the specified complex type to the specified
3853 /// destination type, where the destination type is an LLVM scalar type.
3854 Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src,
3857 SourceLocation Loc) {
3858 assert(SrcTy->isAnyComplexType() && hasScalarEvaluationKind(DstTy) &&
3859 "Invalid complex -> scalar conversion");
3860 return ScalarExprEmitter(*this)
3861 .EmitComplexToScalarConversion(Src, SrcTy, DstTy, Loc);
3865 llvm::Value *CodeGenFunction::
3866 EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
3867 bool isInc, bool isPre) {
3868 return ScalarExprEmitter(*this).EmitScalarPrePostIncDec(E, LV, isInc, isPre);
3871 LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) {
3872 // object->isa or (*object).isa
3873 // Generate code as for: *(Class*)object
3875 Expr *BaseExpr = E->getBase();
3876 Address Addr = Address::invalid();
3877 if (BaseExpr->isRValue()) {
3878 Addr = Address(EmitScalarExpr(BaseExpr), getPointerAlign());
3880 Addr = EmitLValue(BaseExpr).getAddress();
3883 // Cast the address to Class*.
3884 Addr = Builder.CreateElementBitCast(Addr, ConvertType(E->getType()));
3885 return MakeAddrLValue(Addr, E->getType());
3889 LValue CodeGenFunction::EmitCompoundAssignmentLValue(
3890 const CompoundAssignOperator *E) {
3891 ScalarExprEmitter Scalar(*this);
3892 Value *Result = nullptr;
3893 switch (E->getOpcode()) {
3894 #define COMPOUND_OP(Op) \
3895 case BO_##Op##Assign: \
3896 return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \
3933 llvm_unreachable("Not valid compound assignment operators");
3936 llvm_unreachable("Unhandled compound assignment operator");
3939 Value *CodeGenFunction::EmitCheckedInBoundsGEP(Value *Ptr,
3940 ArrayRef<Value *> IdxList,
3944 const Twine &Name) {
3945 Value *GEPVal = Builder.CreateInBoundsGEP(Ptr, IdxList, Name);
3947 // If the pointer overflow sanitizer isn't enabled, do nothing.
3948 if (!SanOpts.has(SanitizerKind::PointerOverflow))
3951 // If the GEP has already been reduced to a constant, leave it be.
3952 if (isa<llvm::Constant>(GEPVal))
3955 // Only check for overflows in the default address space.
3956 if (GEPVal->getType()->getPointerAddressSpace())
3959 auto *GEP = cast<llvm::GEPOperator>(GEPVal);
3960 assert(GEP->isInBounds() && "Expected inbounds GEP");
3962 SanitizerScope SanScope(this);
3963 auto &VMContext = getLLVMContext();
3964 const auto &DL = CGM.getDataLayout();
3965 auto *IntPtrTy = DL.getIntPtrType(GEP->getPointerOperandType());
3967 // Grab references to the signed add/mul overflow intrinsics for intptr_t.
3968 auto *Zero = llvm::ConstantInt::getNullValue(IntPtrTy);
3969 auto *SAddIntrinsic =
3970 CGM.getIntrinsic(llvm::Intrinsic::sadd_with_overflow, IntPtrTy);
3971 auto *SMulIntrinsic =
3972 CGM.getIntrinsic(llvm::Intrinsic::smul_with_overflow, IntPtrTy);
3974 // The total (signed) byte offset for the GEP.
3975 llvm::Value *TotalOffset = nullptr;
3976 // The offset overflow flag - true if the total offset overflows.
3977 llvm::Value *OffsetOverflows = Builder.getFalse();
3979 /// Return the result of the given binary operation.
3980 auto eval = [&](BinaryOperator::Opcode Opcode, llvm::Value *LHS,
3981 llvm::Value *RHS) -> llvm::Value * {
3982 assert((Opcode == BO_Add || Opcode == BO_Mul) && "Can't eval binop");
3984 // If the operands are constants, return a constant result.
3985 if (auto *LHSCI = dyn_cast<llvm::ConstantInt>(LHS)) {
3986 if (auto *RHSCI = dyn_cast<llvm::ConstantInt>(RHS)) {
3988 bool HasOverflow = mayHaveIntegerOverflow(LHSCI, RHSCI, Opcode,
3989 /*Signed=*/true, N);
3991 OffsetOverflows = Builder.getTrue();
3992 return llvm::ConstantInt::get(VMContext, N);
3996 // Otherwise, compute the result with checked arithmetic.
3997 auto *ResultAndOverflow = Builder.CreateCall(
3998 (Opcode == BO_Add) ? SAddIntrinsic : SMulIntrinsic, {LHS, RHS});
3999 OffsetOverflows = Builder.CreateOr(
4000 Builder.CreateExtractValue(ResultAndOverflow, 1), OffsetOverflows);
4001 return Builder.CreateExtractValue(ResultAndOverflow, 0);
4004 // Determine the total byte offset by looking at each GEP operand.
4005 for (auto GTI = llvm::gep_type_begin(GEP), GTE = llvm::gep_type_end(GEP);
4006 GTI != GTE; ++GTI) {
4007 llvm::Value *LocalOffset;
4008 auto *Index = GTI.getOperand();
4009 // Compute the local offset contributed by this indexing step:
4010 if (auto *STy = GTI.getStructTypeOrNull()) {
4011 // For struct indexing, the local offset is the byte position of the
4013 unsigned FieldNo = cast<llvm::ConstantInt>(Index)->getZExtValue();
4014 LocalOffset = llvm::ConstantInt::get(
4015 IntPtrTy, DL.getStructLayout(STy)->getElementOffset(FieldNo));
4017 // Otherwise this is array-like indexing. The local offset is the index
4018 // multiplied by the element size.
4019 auto *ElementSize = llvm::ConstantInt::get(
4020 IntPtrTy, DL.getTypeAllocSize(GTI.getIndexedType()));
4021 auto *IndexS = Builder.CreateIntCast(Index, IntPtrTy, /*isSigned=*/true);
4022 LocalOffset = eval(BO_Mul, ElementSize, IndexS);
4025 // If this is the first offset, set it as the total offset. Otherwise, add
4026 // the local offset into the running total.
4027 if (!TotalOffset || TotalOffset == Zero)
4028 TotalOffset = LocalOffset;
4030 TotalOffset = eval(BO_Add, TotalOffset, LocalOffset);
4033 // Common case: if the total offset is zero, don't emit a check.
4034 if (TotalOffset == Zero)
4037 // Now that we've computed the total offset, add it to the base pointer (with
4038 // wrapping semantics).
4039 auto *IntPtr = Builder.CreatePtrToInt(GEP->getPointerOperand(), IntPtrTy);
4040 auto *ComputedGEP = Builder.CreateAdd(IntPtr, TotalOffset);
4042 // The GEP is valid if:
4043 // 1) The total offset doesn't overflow, and
4044 // 2) The sign of the difference between the computed address and the base
4045 // pointer matches the sign of the total offset.
4046 llvm::Value *ValidGEP;
4047 auto *NoOffsetOverflow = Builder.CreateNot(OffsetOverflows);
4048 if (SignedIndices) {
4049 auto *PosOrZeroValid = Builder.CreateICmpUGE(ComputedGEP, IntPtr);
4050 auto *PosOrZeroOffset = Builder.CreateICmpSGE(TotalOffset, Zero);
4051 llvm::Value *NegValid = Builder.CreateICmpULT(ComputedGEP, IntPtr);
4052 ValidGEP = Builder.CreateAnd(
4053 Builder.CreateSelect(PosOrZeroOffset, PosOrZeroValid, NegValid),
4055 } else if (!SignedIndices && !IsSubtraction) {
4056 auto *PosOrZeroValid = Builder.CreateICmpUGE(ComputedGEP, IntPtr);
4057 ValidGEP = Builder.CreateAnd(PosOrZeroValid, NoOffsetOverflow);
4059 auto *NegOrZeroValid = Builder.CreateICmpULE(ComputedGEP, IntPtr);
4060 ValidGEP = Builder.CreateAnd(NegOrZeroValid, NoOffsetOverflow);
4063 llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc)};
4064 // Pass the computed GEP to the runtime to avoid emitting poisoned arguments.
4065 llvm::Value *DynamicArgs[] = {IntPtr, ComputedGEP};
4066 EmitCheck(std::make_pair(ValidGEP, SanitizerKind::PointerOverflow),
4067 SanitizerHandler::PointerOverflow, StaticArgs, DynamicArgs);