1//===--- CGExprScalar.cpp - Emit LLVM Code for Scalar Exprs ---------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This contains code to emit Expr nodes with scalar LLVM types as LLVM code. 11// 12//===----------------------------------------------------------------------===// 13 14#include "CodeGenFunction.h" 15#include "CGCXXABI.h" 16#include "CGDebugInfo.h" 17#include "CGObjCRuntime.h" 18#include "CodeGenModule.h" 19#include "clang/AST/ASTContext.h" 20#include "clang/AST/DeclObjC.h" 21#include "clang/AST/RecordLayout.h" 22#include "clang/AST/StmtVisitor.h" 23#include "clang/Basic/TargetInfo.h" 24#include "clang/Frontend/CodeGenOptions.h" 25#include "llvm/IR/Constants.h" 26#include "llvm/IR/DataLayout.h" 27#include "llvm/IR/Function.h" 28#include "llvm/IR/GlobalVariable.h" 29#include "llvm/IR/Intrinsics.h" 30#include "llvm/IR/Module.h" 31#include "llvm/Support/CFG.h" 32#include <cstdarg> 33 34using namespace clang; 35using namespace CodeGen; 36using llvm::Value; 37 38//===----------------------------------------------------------------------===// 39// Scalar Expression Emitter 40//===----------------------------------------------------------------------===// 41 42namespace { 43struct BinOpInfo { 44 Value *LHS; 45 Value *RHS; 46 QualType Ty; // Computation Type. 47 BinaryOperator::Opcode Opcode; // Opcode of BinOp to perform 48 bool FPContractable; 49 const Expr *E; // Entire expr, for error unsupported. May not be binop. 50}; 51 52static bool MustVisitNullValue(const Expr *E) { 53 // If a null pointer expression's type is the C++0x nullptr_t, then 54 // it's not necessarily a simple constant and it must be evaluated 55 // for its potential side effects. 56 return E->getType()->isNullPtrType(); 57} 58 59class ScalarExprEmitter 60 : public StmtVisitor<ScalarExprEmitter, Value*> { 61 CodeGenFunction &CGF; 62 CGBuilderTy &Builder; 63 bool IgnoreResultAssign; 64 llvm::LLVMContext &VMContext; 65public: 66 67 ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false) 68 : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira), 69 VMContext(cgf.getLLVMContext()) { 70 } 71 72 //===--------------------------------------------------------------------===// 73 // Utilities 74 //===--------------------------------------------------------------------===// 75 76 bool TestAndClearIgnoreResultAssign() { 77 bool I = IgnoreResultAssign; 78 IgnoreResultAssign = false; 79 return I; 80 } 81 82 llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); } 83 LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); } 84 LValue EmitCheckedLValue(const Expr *E, CodeGenFunction::TypeCheckKind TCK) { 85 return CGF.EmitCheckedLValue(E, TCK); 86 } 87 88 void EmitBinOpCheck(Value *Check, const BinOpInfo &Info); 89 90 Value *EmitLoadOfLValue(LValue LV, SourceLocation Loc) { 91 return CGF.EmitLoadOfLValue(LV, Loc).getScalarVal(); 92 } 93 94 /// EmitLoadOfLValue - Given an expression with complex type that represents a 95 /// value l-value, this method emits the address of the l-value, then loads 96 /// and returns the result. 97 Value *EmitLoadOfLValue(const Expr *E) { 98 return EmitLoadOfLValue(EmitCheckedLValue(E, CodeGenFunction::TCK_Load), 99 E->getExprLoc()); 100 } 101 102 /// EmitConversionToBool - Convert the specified expression value to a 103 /// boolean (i1) truth value. This is equivalent to "Val != 0". 104 Value *EmitConversionToBool(Value *Src, QualType DstTy); 105 106 /// \brief Emit a check that a conversion to or from a floating-point type 107 /// does not overflow. 108 void EmitFloatConversionCheck(Value *OrigSrc, QualType OrigSrcType, 109 Value *Src, QualType SrcType, 110 QualType DstType, llvm::Type *DstTy); 111 112 /// EmitScalarConversion - Emit a conversion from the specified type to the 113 /// specified destination type, both of which are LLVM scalar types. 114 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); 115 116 /// EmitComplexToScalarConversion - Emit a conversion from the specified 117 /// complex type to the specified destination type, where the destination type 118 /// is an LLVM scalar type. 119 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 120 QualType SrcTy, QualType DstTy); 121 122 /// EmitNullValue - Emit a value that corresponds to null for the given type. 123 Value *EmitNullValue(QualType Ty); 124 125 /// EmitFloatToBoolConversion - Perform an FP to boolean conversion. 126 Value *EmitFloatToBoolConversion(Value *V) { 127 // Compare against 0.0 for fp scalars. 128 llvm::Value *Zero = llvm::Constant::getNullValue(V->getType()); 129 return Builder.CreateFCmpUNE(V, Zero, "tobool"); 130 } 131 132 /// EmitPointerToBoolConversion - Perform a pointer to boolean conversion. 133 Value *EmitPointerToBoolConversion(Value *V) { 134 Value *Zero = llvm::ConstantPointerNull::get( 135 cast<llvm::PointerType>(V->getType())); 136 return Builder.CreateICmpNE(V, Zero, "tobool"); 137 } 138 139 Value *EmitIntToBoolConversion(Value *V) { 140 // Because of the type rules of C, we often end up computing a 141 // logical value, then zero extending it to int, then wanting it 142 // as a logical value again. Optimize this common case. 143 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(V)) { 144 if (ZI->getOperand(0)->getType() == Builder.getInt1Ty()) { 145 Value *Result = ZI->getOperand(0); 146 // If there aren't any more uses, zap the instruction to save space. 147 // Note that there can be more uses, for example if this 148 // is the result of an assignment. 149 if (ZI->use_empty()) 150 ZI->eraseFromParent(); 151 return Result; 152 } 153 } 154 155 return Builder.CreateIsNotNull(V, "tobool"); 156 } 157 158 //===--------------------------------------------------------------------===// 159 // Visitor Methods 160 //===--------------------------------------------------------------------===// 161 162 Value *Visit(Expr *E) { 163 return StmtVisitor<ScalarExprEmitter, Value*>::Visit(E); 164 } 165 166 Value *VisitStmt(Stmt *S) { 167 S->dump(CGF.getContext().getSourceManager()); 168 llvm_unreachable("Stmt can't have complex result type!"); 169 } 170 Value *VisitExpr(Expr *S); 171 172 Value *VisitParenExpr(ParenExpr *PE) { 173 return Visit(PE->getSubExpr()); 174 } 175 Value *VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) { 176 return Visit(E->getReplacement()); 177 } 178 Value *VisitGenericSelectionExpr(GenericSelectionExpr *GE) { 179 return Visit(GE->getResultExpr()); 180 } 181 182 // Leaves. 183 Value *VisitIntegerLiteral(const IntegerLiteral *E) { 184 return Builder.getInt(E->getValue()); 185 } 186 Value *VisitFloatingLiteral(const FloatingLiteral *E) { 187 return llvm::ConstantFP::get(VMContext, E->getValue()); 188 } 189 Value *VisitCharacterLiteral(const CharacterLiteral *E) { 190 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 191 } 192 Value *VisitObjCBoolLiteralExpr(const ObjCBoolLiteralExpr *E) { 193 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 194 } 195 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 196 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 197 } 198 Value *VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) { 199 return EmitNullValue(E->getType()); 200 } 201 Value *VisitGNUNullExpr(const GNUNullExpr *E) { 202 return EmitNullValue(E->getType()); 203 } 204 Value *VisitOffsetOfExpr(OffsetOfExpr *E); 205 Value *VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E); 206 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 207 llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel()); 208 return Builder.CreateBitCast(V, ConvertType(E->getType())); 209 } 210 211 Value *VisitSizeOfPackExpr(SizeOfPackExpr *E) { 212 return llvm::ConstantInt::get(ConvertType(E->getType()),E->getPackLength()); 213 } 214 215 Value *VisitPseudoObjectExpr(PseudoObjectExpr *E) { 216 return CGF.EmitPseudoObjectRValue(E).getScalarVal(); 217 } 218 219 Value *VisitOpaqueValueExpr(OpaqueValueExpr *E) { 220 if (E->isGLValue()) 221 return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E), E->getExprLoc()); 222 223 // Otherwise, assume the mapping is the scalar directly. 224 return CGF.getOpaqueRValueMapping(E).getScalarVal(); 225 } 226 227 // l-values. 228 Value *VisitDeclRefExpr(DeclRefExpr *E) { 229 if (CodeGenFunction::ConstantEmission result = CGF.tryEmitAsConstant(E)) { 230 if (result.isReference()) 231 return EmitLoadOfLValue(result.getReferenceLValue(CGF, E), 232 E->getExprLoc()); 233 return result.getValue(); 234 } 235 return EmitLoadOfLValue(E); 236 } 237 238 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 239 return CGF.EmitObjCSelectorExpr(E); 240 } 241 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 242 return CGF.EmitObjCProtocolExpr(E); 243 } 244 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 245 return EmitLoadOfLValue(E); 246 } 247 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 248 if (E->getMethodDecl() && 249 E->getMethodDecl()->getResultType()->isReferenceType()) 250 return EmitLoadOfLValue(E); 251 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 252 } 253 254 Value *VisitObjCIsaExpr(ObjCIsaExpr *E) { 255 LValue LV = CGF.EmitObjCIsaExpr(E); 256 Value *V = CGF.EmitLoadOfLValue(LV, E->getExprLoc()).getScalarVal(); 257 return V; 258 } 259 260 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 261 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 262 Value *VisitConvertVectorExpr(ConvertVectorExpr *E); 263 Value *VisitMemberExpr(MemberExpr *E); 264 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 265 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 266 return EmitLoadOfLValue(E); 267 } 268 269 Value *VisitInitListExpr(InitListExpr *E); 270 271 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { 272 return EmitNullValue(E->getType()); 273 } 274 Value *VisitExplicitCastExpr(ExplicitCastExpr *E) { 275 if (E->getType()->isVariablyModifiedType()) 276 CGF.EmitVariablyModifiedType(E->getType()); 277 return VisitCastExpr(E); 278 } 279 Value *VisitCastExpr(CastExpr *E); 280 281 Value *VisitCallExpr(const CallExpr *E) { 282 if (E->getCallReturnType()->isReferenceType()) 283 return EmitLoadOfLValue(E); 284 285 return CGF.EmitCallExpr(E).getScalarVal(); 286 } 287 288 Value *VisitStmtExpr(const StmtExpr *E); 289 290 // Unary Operators. 291 Value *VisitUnaryPostDec(const UnaryOperator *E) { 292 LValue LV = EmitLValue(E->getSubExpr()); 293 return EmitScalarPrePostIncDec(E, LV, false, false); 294 } 295 Value *VisitUnaryPostInc(const UnaryOperator *E) { 296 LValue LV = EmitLValue(E->getSubExpr()); 297 return EmitScalarPrePostIncDec(E, LV, true, false); 298 } 299 Value *VisitUnaryPreDec(const UnaryOperator *E) { 300 LValue LV = EmitLValue(E->getSubExpr()); 301 return EmitScalarPrePostIncDec(E, LV, false, true); 302 } 303 Value *VisitUnaryPreInc(const UnaryOperator *E) { 304 LValue LV = EmitLValue(E->getSubExpr()); 305 return EmitScalarPrePostIncDec(E, LV, true, true); 306 } 307 308 llvm::Value *EmitAddConsiderOverflowBehavior(const UnaryOperator *E, 309 llvm::Value *InVal, 310 llvm::Value *NextVal, 311 bool IsInc); 312 313 llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 314 bool isInc, bool isPre); 315 316 317 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 318 if (isa<MemberPointerType>(E->getType())) // never sugared 319 return CGF.CGM.getMemberPointerConstant(E); 320 321 return EmitLValue(E->getSubExpr()).getAddress(); 322 } 323 Value *VisitUnaryDeref(const UnaryOperator *E) { 324 if (E->getType()->isVoidType()) 325 return Visit(E->getSubExpr()); // the actual value should be unused 326 return EmitLoadOfLValue(E); 327 } 328 Value *VisitUnaryPlus(const UnaryOperator *E) { 329 // This differs from gcc, though, most likely due to a bug in gcc. 330 TestAndClearIgnoreResultAssign(); 331 return Visit(E->getSubExpr()); 332 } 333 Value *VisitUnaryMinus (const UnaryOperator *E); 334 Value *VisitUnaryNot (const UnaryOperator *E); 335 Value *VisitUnaryLNot (const UnaryOperator *E); 336 Value *VisitUnaryReal (const UnaryOperator *E); 337 Value *VisitUnaryImag (const UnaryOperator *E); 338 Value *VisitUnaryExtension(const UnaryOperator *E) { 339 return Visit(E->getSubExpr()); 340 } 341 342 // C++ 343 Value *VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E) { 344 return EmitLoadOfLValue(E); 345 } 346 347 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 348 return Visit(DAE->getExpr()); 349 } 350 Value *VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) { 351 CodeGenFunction::CXXDefaultInitExprScope Scope(CGF); 352 return Visit(DIE->getExpr()); 353 } 354 Value *VisitCXXThisExpr(CXXThisExpr *TE) { 355 return CGF.LoadCXXThis(); 356 } 357 358 Value *VisitExprWithCleanups(ExprWithCleanups *E) { 359 CGF.enterFullExpression(E); 360 CodeGenFunction::RunCleanupsScope Scope(CGF); 361 return Visit(E->getSubExpr()); 362 } 363 Value *VisitCXXNewExpr(const CXXNewExpr *E) { 364 return CGF.EmitCXXNewExpr(E); 365 } 366 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { 367 CGF.EmitCXXDeleteExpr(E); 368 return 0; 369 } 370 Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) { 371 return Builder.getInt1(E->getValue()); 372 } 373 374 Value *VisitBinaryTypeTraitExpr(const BinaryTypeTraitExpr *E) { 375 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 376 } 377 378 Value *VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) { 379 return llvm::ConstantInt::get(Builder.getInt32Ty(), E->getValue()); 380 } 381 382 Value *VisitExpressionTraitExpr(const ExpressionTraitExpr *E) { 383 return llvm::ConstantInt::get(Builder.getInt1Ty(), E->getValue()); 384 } 385 386 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { 387 // C++ [expr.pseudo]p1: 388 // The result shall only be used as the operand for the function call 389 // operator (), and the result of such a call has type void. The only 390 // effect is the evaluation of the postfix-expression before the dot or 391 // arrow. 392 CGF.EmitScalarExpr(E->getBase()); 393 return 0; 394 } 395 396 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { 397 return EmitNullValue(E->getType()); 398 } 399 400 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { 401 CGF.EmitCXXThrowExpr(E); 402 return 0; 403 } 404 405 Value *VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) { 406 return Builder.getInt1(E->getValue()); 407 } 408 409 // Binary Operators. 410 Value *EmitMul(const BinOpInfo &Ops) { 411 if (Ops.Ty->isSignedIntegerOrEnumerationType()) { 412 switch (CGF.getLangOpts().getSignedOverflowBehavior()) { 413 case LangOptions::SOB_Defined: 414 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 415 case LangOptions::SOB_Undefined: 416 if (!CGF.SanOpts->SignedIntegerOverflow) 417 return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul"); 418 // Fall through. 419 case LangOptions::SOB_Trapping: 420 return EmitOverflowCheckedBinOp(Ops); 421 } 422 } 423 424 if (Ops.Ty->isUnsignedIntegerType() && CGF.SanOpts->UnsignedIntegerOverflow) 425 return EmitOverflowCheckedBinOp(Ops); 426 427 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 428 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 429 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 430 } 431 /// Create a binary op that checks for overflow. 432 /// Currently only supports +, - and *. 433 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 434 435 // Check for undefined division and modulus behaviors. 436 void EmitUndefinedBehaviorIntegerDivAndRemCheck(const BinOpInfo &Ops, 437 llvm::Value *Zero,bool isDiv); 438 // Common helper for getting how wide LHS of shift is. 439 static Value *GetWidthMinusOneValue(Value* LHS,Value* RHS); 440 Value *EmitDiv(const BinOpInfo &Ops); 441 Value *EmitRem(const BinOpInfo &Ops); 442 Value *EmitAdd(const BinOpInfo &Ops); 443 Value *EmitSub(const BinOpInfo &Ops); 444 Value *EmitShl(const BinOpInfo &Ops); 445 Value *EmitShr(const BinOpInfo &Ops); 446 Value *EmitAnd(const BinOpInfo &Ops) { 447 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 448 } 449 Value *EmitXor(const BinOpInfo &Ops) { 450 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 451 } 452 Value *EmitOr (const BinOpInfo &Ops) { 453 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 454 } 455 456 BinOpInfo EmitBinOps(const BinaryOperator *E); 457 LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E, 458 Value *(ScalarExprEmitter::*F)(const BinOpInfo &), 459 Value *&Result); 460 461 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 462 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 463 464 // Binary operators and binary compound assignment operators. 465#define HANDLEBINOP(OP) \ 466 Value *VisitBin ## OP(const BinaryOperator *E) { \ 467 return Emit ## OP(EmitBinOps(E)); \ 468 } \ 469 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 470 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 471 } 472 HANDLEBINOP(Mul) 473 HANDLEBINOP(Div) 474 HANDLEBINOP(Rem) 475 HANDLEBINOP(Add) 476 HANDLEBINOP(Sub) 477 HANDLEBINOP(Shl) 478 HANDLEBINOP(Shr) 479 HANDLEBINOP(And) 480 HANDLEBINOP(Xor) 481 HANDLEBINOP(Or) 482#undef HANDLEBINOP 483 484 // Comparisons. 485 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 486 unsigned SICmpOpc, unsigned FCmpOpc); 487#define VISITCOMP(CODE, UI, SI, FP) \ 488 Value *VisitBin##CODE(const BinaryOperator *E) { \ 489 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 490 llvm::FCmpInst::FP); } 491 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT) 492 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT) 493 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE) 494 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE) 495 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ) 496 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE) 497#undef VISITCOMP 498 499 Value *VisitBinAssign (const BinaryOperator *E); 500 501 Value *VisitBinLAnd (const BinaryOperator *E); 502 Value *VisitBinLOr (const BinaryOperator *E); 503 Value *VisitBinComma (const BinaryOperator *E); 504 505 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } 506 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); } 507 508 // Other Operators. 509 Value *VisitBlockExpr(const BlockExpr *BE); 510 Value *VisitAbstractConditionalOperator(const AbstractConditionalOperator *); 511 Value *VisitChooseExpr(ChooseExpr *CE); 512 Value *VisitVAArgExpr(VAArgExpr *VE); 513 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 514 return CGF.EmitObjCStringLiteral(E); 515 } 516 Value *VisitObjCBoxedExpr(ObjCBoxedExpr *E) { 517 return CGF.EmitObjCBoxedExpr(E); 518 } 519 Value *VisitObjCArrayLiteral(ObjCArrayLiteral *E) { 520 return CGF.EmitObjCArrayLiteral(E); 521 } 522 Value *VisitObjCDictionaryLiteral(ObjCDictionaryLiteral *E) { 523 return CGF.EmitObjCDictionaryLiteral(E); 524 } 525 Value *VisitAsTypeExpr(AsTypeExpr *CE); 526 Value *VisitAtomicExpr(AtomicExpr *AE); 527}; 528} // end anonymous namespace. 529 530//===----------------------------------------------------------------------===// 531// Utilities 532//===----------------------------------------------------------------------===// 533 534/// EmitConversionToBool - Convert the specified expression value to a 535/// boolean (i1) truth value. This is equivalent to "Val != 0". 536Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 537 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs"); 538 539 if (SrcType->isRealFloatingType()) 540 return EmitFloatToBoolConversion(Src); 541 542 if (const MemberPointerType *MPT = dyn_cast<MemberPointerType>(SrcType)) 543 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, Src, MPT); 544 545 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 546 "Unknown scalar type to convert"); 547 548 if (isa<llvm::IntegerType>(Src->getType())) 549 return EmitIntToBoolConversion(Src); 550 551 assert(isa<llvm::PointerType>(Src->getType())); 552 return EmitPointerToBoolConversion(Src); 553} 554 555void ScalarExprEmitter::EmitFloatConversionCheck(Value *OrigSrc, 556 QualType OrigSrcType, 557 Value *Src, QualType SrcType, 558 QualType DstType, 559 llvm::Type *DstTy) { 560 using llvm::APFloat; 561 using llvm::APSInt; 562 563 llvm::Type *SrcTy = Src->getType(); 564 565 llvm::Value *Check = 0; 566 if (llvm::IntegerType *IntTy = dyn_cast<llvm::IntegerType>(SrcTy)) { 567 // Integer to floating-point. This can fail for unsigned short -> __half 568 // or unsigned __int128 -> float. 569 assert(DstType->isFloatingType()); 570 bool SrcIsUnsigned = OrigSrcType->isUnsignedIntegerOrEnumerationType(); 571 572 APFloat LargestFloat = 573 APFloat::getLargest(CGF.getContext().getFloatTypeSemantics(DstType)); 574 APSInt LargestInt(IntTy->getBitWidth(), SrcIsUnsigned); 575 576 bool IsExact; 577 if (LargestFloat.convertToInteger(LargestInt, APFloat::rmTowardZero, 578 &IsExact) != APFloat::opOK) 579 // The range of representable values of this floating point type includes 580 // all values of this integer type. Don't need an overflow check. 581 return; 582 583 llvm::Value *Max = llvm::ConstantInt::get(VMContext, LargestInt); 584 if (SrcIsUnsigned) 585 Check = Builder.CreateICmpULE(Src, Max); 586 else { 587 llvm::Value *Min = llvm::ConstantInt::get(VMContext, -LargestInt); 588 llvm::Value *GE = Builder.CreateICmpSGE(Src, Min); 589 llvm::Value *LE = Builder.CreateICmpSLE(Src, Max); 590 Check = Builder.CreateAnd(GE, LE); 591 } 592 } else { 593 const llvm::fltSemantics &SrcSema = 594 CGF.getContext().getFloatTypeSemantics(OrigSrcType); 595 if (isa<llvm::IntegerType>(DstTy)) { 596 // Floating-point to integer. This has undefined behavior if the source is 597 // +-Inf, NaN, or doesn't fit into the destination type (after truncation 598 // to an integer). 599 unsigned Width = CGF.getContext().getIntWidth(DstType); 600 bool Unsigned = DstType->isUnsignedIntegerOrEnumerationType(); 601 602 APSInt Min = APSInt::getMinValue(Width, Unsigned); 603 APFloat MinSrc(SrcSema, APFloat::uninitialized); 604 if (MinSrc.convertFromAPInt(Min, !Unsigned, APFloat::rmTowardZero) & 605 APFloat::opOverflow) 606 // Don't need an overflow check for lower bound. Just check for 607 // -Inf/NaN. 608 MinSrc = APFloat::getInf(SrcSema, true); 609 else 610 // Find the largest value which is too small to represent (before 611 // truncation toward zero). 612 MinSrc.subtract(APFloat(SrcSema, 1), APFloat::rmTowardNegative); 613 614 APSInt Max = APSInt::getMaxValue(Width, Unsigned); 615 APFloat MaxSrc(SrcSema, APFloat::uninitialized); 616 if (MaxSrc.convertFromAPInt(Max, !Unsigned, APFloat::rmTowardZero) & 617 APFloat::opOverflow) 618 // Don't need an overflow check for upper bound. Just check for 619 // +Inf/NaN. 620 MaxSrc = APFloat::getInf(SrcSema, false); 621 else 622 // Find the smallest value which is too large to represent (before 623 // truncation toward zero). 624 MaxSrc.add(APFloat(SrcSema, 1), APFloat::rmTowardPositive); 625 626 // If we're converting from __half, convert the range to float to match 627 // the type of src. 628 if (OrigSrcType->isHalfType()) { 629 const llvm::fltSemantics &Sema = 630 CGF.getContext().getFloatTypeSemantics(SrcType); 631 bool IsInexact; 632 MinSrc.convert(Sema, APFloat::rmTowardZero, &IsInexact); 633 MaxSrc.convert(Sema, APFloat::rmTowardZero, &IsInexact); 634 } 635 636 llvm::Value *GE = 637 Builder.CreateFCmpOGT(Src, llvm::ConstantFP::get(VMContext, MinSrc)); 638 llvm::Value *LE = 639 Builder.CreateFCmpOLT(Src, llvm::ConstantFP::get(VMContext, MaxSrc)); 640 Check = Builder.CreateAnd(GE, LE); 641 } else { 642 // FIXME: Maybe split this sanitizer out from float-cast-overflow. 643 // 644 // Floating-point to floating-point. This has undefined behavior if the 645 // source is not in the range of representable values of the destination 646 // type. The C and C++ standards are spectacularly unclear here. We 647 // diagnose finite out-of-range conversions, but allow infinities and NaNs 648 // to convert to the corresponding value in the smaller type. 649 // 650 // C11 Annex F gives all such conversions defined behavior for IEC 60559 651 // conforming implementations. Unfortunately, LLVM's fptrunc instruction 652 // does not. 653 654 // Converting from a lower rank to a higher rank can never have 655 // undefined behavior, since higher-rank types must have a superset 656 // of values of lower-rank types. 657 if (CGF.getContext().getFloatingTypeOrder(OrigSrcType, DstType) != 1) 658 return; 659 660 assert(!OrigSrcType->isHalfType() && 661 "should not check conversion from __half, it has the lowest rank"); 662 663 const llvm::fltSemantics &DstSema = 664 CGF.getContext().getFloatTypeSemantics(DstType); 665 APFloat MinBad = APFloat::getLargest(DstSema, false); 666 APFloat MaxBad = APFloat::getInf(DstSema, false); 667 668 bool IsInexact; 669 MinBad.convert(SrcSema, APFloat::rmTowardZero, &IsInexact); 670 MaxBad.convert(SrcSema, APFloat::rmTowardZero, &IsInexact); 671 672 Value *AbsSrc = CGF.EmitNounwindRuntimeCall( 673 CGF.CGM.getIntrinsic(llvm::Intrinsic::fabs, Src->getType()), Src); 674 llvm::Value *GE = 675 Builder.CreateFCmpOGT(AbsSrc, llvm::ConstantFP::get(VMContext, MinBad)); 676 llvm::Value *LE = 677 Builder.CreateFCmpOLT(AbsSrc, llvm::ConstantFP::get(VMContext, MaxBad)); 678 Check = Builder.CreateNot(Builder.CreateAnd(GE, LE)); 679 } 680 } 681 682 // FIXME: Provide a SourceLocation. 683 llvm::Constant *StaticArgs[] = { 684 CGF.EmitCheckTypeDescriptor(OrigSrcType), 685 CGF.EmitCheckTypeDescriptor(DstType) 686 }; 687 CGF.EmitCheck(Check, "float_cast_overflow", StaticArgs, OrigSrc, 688 CodeGenFunction::CRK_Recoverable); 689} 690 691/// EmitScalarConversion - Emit a conversion from the specified type to the 692/// specified destination type, both of which are LLVM scalar types. 693Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 694 QualType DstType) { 695 SrcType = CGF.getContext().getCanonicalType(SrcType); 696 DstType = CGF.getContext().getCanonicalType(DstType); 697 if (SrcType == DstType) return Src; 698 699 if (DstType->isVoidType()) return 0; 700 701 llvm::Value *OrigSrc = Src; 702 QualType OrigSrcType = SrcType; 703 llvm::Type *SrcTy = Src->getType(); 704 705 // If casting to/from storage-only half FP, use special intrinsics. 706 if (SrcType->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) { 707 Src = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16), Src); 708 SrcType = CGF.getContext().FloatTy; 709 SrcTy = CGF.FloatTy; 710 } 711 712 // Handle conversions to bool first, they are special: comparisons against 0. 713 if (DstType->isBooleanType()) 714 return EmitConversionToBool(Src, SrcType); 715 716 llvm::Type *DstTy = ConvertType(DstType); 717 718 // Ignore conversions like int -> uint. 719 if (SrcTy == DstTy) 720 return Src; 721 722 // Handle pointer conversions next: pointers can only be converted to/from 723 // other pointers and integers. Check for pointer types in terms of LLVM, as 724 // some native types (like Obj-C id) may map to a pointer type. 725 if (isa<llvm::PointerType>(DstTy)) { 726 // The source value may be an integer, or a pointer. 727 if (isa<llvm::PointerType>(SrcTy)) 728 return Builder.CreateBitCast(Src, DstTy, "conv"); 729 730 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 731 // First, convert to the correct width so that we control the kind of 732 // extension. 733 llvm::Type *MiddleTy = CGF.IntPtrTy; 734 bool InputSigned = SrcType->isSignedIntegerOrEnumerationType(); 735 llvm::Value* IntResult = 736 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 737 // Then, cast to pointer. 738 return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); 739 } 740 741 if (isa<llvm::PointerType>(SrcTy)) { 742 // Must be an ptr to int cast. 743 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 744 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 745 } 746 747 // A scalar can be splatted to an extended vector of the same element type 748 if (DstType->isExtVectorType() && !SrcType->isVectorType()) { 749 // Cast the scalar to element type 750 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType(); 751 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 752 753 // Splat the element across to all elements 754 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 755 return Builder.CreateVectorSplat(NumElements, Elt, "splat"); 756 } 757 758 // Allow bitcast from vector to integer/fp of the same size. 759 if (isa<llvm::VectorType>(SrcTy) || 760 isa<llvm::VectorType>(DstTy)) 761 return Builder.CreateBitCast(Src, DstTy, "conv"); 762 763 // Finally, we have the arithmetic types: real int/float. 764 Value *Res = NULL; 765 llvm::Type *ResTy = DstTy; 766 767 // An overflowing conversion has undefined behavior if either the source type 768 // or the destination type is a floating-point type. 769 if (CGF.SanOpts->FloatCastOverflow && 770 (OrigSrcType->isFloatingType() || DstType->isFloatingType())) 771 EmitFloatConversionCheck(OrigSrc, OrigSrcType, Src, SrcType, DstType, 772 DstTy); 773 774 // Cast to half via float 775 if (DstType->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) 776 DstTy = CGF.FloatTy; 777 778 if (isa<llvm::IntegerType>(SrcTy)) { 779 bool InputSigned = SrcType->isSignedIntegerOrEnumerationType(); 780 if (isa<llvm::IntegerType>(DstTy)) 781 Res = Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 782 else if (InputSigned) 783 Res = Builder.CreateSIToFP(Src, DstTy, "conv"); 784 else 785 Res = Builder.CreateUIToFP(Src, DstTy, "conv"); 786 } else if (isa<llvm::IntegerType>(DstTy)) { 787 assert(SrcTy->isFloatingPointTy() && "Unknown real conversion"); 788 if (DstType->isSignedIntegerOrEnumerationType()) 789 Res = Builder.CreateFPToSI(Src, DstTy, "conv"); 790 else 791 Res = Builder.CreateFPToUI(Src, DstTy, "conv"); 792 } else { 793 assert(SrcTy->isFloatingPointTy() && DstTy->isFloatingPointTy() && 794 "Unknown real conversion"); 795 if (DstTy->getTypeID() < SrcTy->getTypeID()) 796 Res = Builder.CreateFPTrunc(Src, DstTy, "conv"); 797 else 798 Res = Builder.CreateFPExt(Src, DstTy, "conv"); 799 } 800 801 if (DstTy != ResTy) { 802 assert(ResTy->isIntegerTy(16) && "Only half FP requires extra conversion"); 803 Res = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16), Res); 804 } 805 806 return Res; 807} 808 809/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 810/// type to the specified destination type, where the destination type is an 811/// LLVM scalar type. 812Value *ScalarExprEmitter:: 813EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 814 QualType SrcTy, QualType DstTy) { 815 // Get the source element type. 816 SrcTy = SrcTy->castAs<ComplexType>()->getElementType(); 817 818 // Handle conversions to bool first, they are special: comparisons against 0. 819 if (DstTy->isBooleanType()) { 820 // Complex != 0 -> (Real != 0) | (Imag != 0) 821 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 822 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 823 return Builder.CreateOr(Src.first, Src.second, "tobool"); 824 } 825 826 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 827 // the imaginary part of the complex value is discarded and the value of the 828 // real part is converted according to the conversion rules for the 829 // corresponding real type. 830 return EmitScalarConversion(Src.first, SrcTy, DstTy); 831} 832 833Value *ScalarExprEmitter::EmitNullValue(QualType Ty) { 834 return CGF.EmitFromMemory(CGF.CGM.EmitNullConstant(Ty), Ty); 835} 836 837/// \brief Emit a sanitization check for the given "binary" operation (which 838/// might actually be a unary increment which has been lowered to a binary 839/// operation). The check passes if \p Check, which is an \c i1, is \c true. 840void ScalarExprEmitter::EmitBinOpCheck(Value *Check, const BinOpInfo &Info) { 841 StringRef CheckName; 842 SmallVector<llvm::Constant *, 4> StaticData; 843 SmallVector<llvm::Value *, 2> DynamicData; 844 845 BinaryOperatorKind Opcode = Info.Opcode; 846 if (BinaryOperator::isCompoundAssignmentOp(Opcode)) 847 Opcode = BinaryOperator::getOpForCompoundAssignment(Opcode); 848 849 StaticData.push_back(CGF.EmitCheckSourceLocation(Info.E->getExprLoc())); 850 const UnaryOperator *UO = dyn_cast<UnaryOperator>(Info.E); 851 if (UO && UO->getOpcode() == UO_Minus) { 852 CheckName = "negate_overflow"; 853 StaticData.push_back(CGF.EmitCheckTypeDescriptor(UO->getType())); 854 DynamicData.push_back(Info.RHS); 855 } else { 856 if (BinaryOperator::isShiftOp(Opcode)) { 857 // Shift LHS negative or too large, or RHS out of bounds. 858 CheckName = "shift_out_of_bounds"; 859 const BinaryOperator *BO = cast<BinaryOperator>(Info.E); 860 StaticData.push_back( 861 CGF.EmitCheckTypeDescriptor(BO->getLHS()->getType())); 862 StaticData.push_back( 863 CGF.EmitCheckTypeDescriptor(BO->getRHS()->getType())); 864 } else if (Opcode == BO_Div || Opcode == BO_Rem) { 865 // Divide or modulo by zero, or signed overflow (eg INT_MAX / -1). 866 CheckName = "divrem_overflow"; 867 StaticData.push_back(CGF.EmitCheckTypeDescriptor(Info.Ty)); 868 } else { 869 // Signed arithmetic overflow (+, -, *). 870 switch (Opcode) { 871 case BO_Add: CheckName = "add_overflow"; break; 872 case BO_Sub: CheckName = "sub_overflow"; break; 873 case BO_Mul: CheckName = "mul_overflow"; break; 874 default: llvm_unreachable("unexpected opcode for bin op check"); 875 } 876 StaticData.push_back(CGF.EmitCheckTypeDescriptor(Info.Ty)); 877 } 878 DynamicData.push_back(Info.LHS); 879 DynamicData.push_back(Info.RHS); 880 } 881 882 CGF.EmitCheck(Check, CheckName, StaticData, DynamicData, 883 CodeGenFunction::CRK_Recoverable); 884} 885 886//===----------------------------------------------------------------------===// 887// Visitor Methods 888//===----------------------------------------------------------------------===// 889 890Value *ScalarExprEmitter::VisitExpr(Expr *E) { 891 CGF.ErrorUnsupported(E, "scalar expression"); 892 if (E->getType()->isVoidType()) 893 return 0; 894 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 895} 896 897Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 898 // Vector Mask Case 899 if (E->getNumSubExprs() == 2 || 900 (E->getNumSubExprs() == 3 && E->getExpr(2)->getType()->isVectorType())) { 901 Value *LHS = CGF.EmitScalarExpr(E->getExpr(0)); 902 Value *RHS = CGF.EmitScalarExpr(E->getExpr(1)); 903 Value *Mask; 904 905 llvm::VectorType *LTy = cast<llvm::VectorType>(LHS->getType()); 906 unsigned LHSElts = LTy->getNumElements(); 907 908 if (E->getNumSubExprs() == 3) { 909 Mask = CGF.EmitScalarExpr(E->getExpr(2)); 910 911 // Shuffle LHS & RHS into one input vector. 912 SmallVector<llvm::Constant*, 32> concat; 913 for (unsigned i = 0; i != LHSElts; ++i) { 914 concat.push_back(Builder.getInt32(2*i)); 915 concat.push_back(Builder.getInt32(2*i+1)); 916 } 917 918 Value* CV = llvm::ConstantVector::get(concat); 919 LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat"); 920 LHSElts *= 2; 921 } else { 922 Mask = RHS; 923 } 924 925 llvm::VectorType *MTy = cast<llvm::VectorType>(Mask->getType()); 926 llvm::Constant* EltMask; 927 928 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 929 llvm::NextPowerOf2(LHSElts-1)-1); 930 931 // Mask off the high bits of each shuffle index. 932 Value *MaskBits = llvm::ConstantVector::getSplat(MTy->getNumElements(), 933 EltMask); 934 Mask = Builder.CreateAnd(Mask, MaskBits, "mask"); 935 936 // newv = undef 937 // mask = mask & maskbits 938 // for each elt 939 // n = extract mask i 940 // x = extract val n 941 // newv = insert newv, x, i 942 llvm::VectorType *RTy = llvm::VectorType::get(LTy->getElementType(), 943 MTy->getNumElements()); 944 Value* NewV = llvm::UndefValue::get(RTy); 945 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) { 946 Value *IIndx = Builder.getInt32(i); 947 Value *Indx = Builder.CreateExtractElement(Mask, IIndx, "shuf_idx"); 948 Indx = Builder.CreateZExt(Indx, CGF.Int32Ty, "idx_zext"); 949 950 Value *VExt = Builder.CreateExtractElement(LHS, Indx, "shuf_elt"); 951 NewV = Builder.CreateInsertElement(NewV, VExt, IIndx, "shuf_ins"); 952 } 953 return NewV; 954 } 955 956 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 957 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 958 959 SmallVector<llvm::Constant*, 32> indices; 960 for (unsigned i = 2; i < E->getNumSubExprs(); ++i) { 961 llvm::APSInt Idx = E->getShuffleMaskIdx(CGF.getContext(), i-2); 962 // Check for -1 and output it as undef in the IR. 963 if (Idx.isSigned() && Idx.isAllOnesValue()) 964 indices.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 965 else 966 indices.push_back(Builder.getInt32(Idx.getZExtValue())); 967 } 968 969 Value *SV = llvm::ConstantVector::get(indices); 970 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 971} 972 973Value *ScalarExprEmitter::VisitConvertVectorExpr(ConvertVectorExpr *E) { 974 QualType SrcType = E->getSrcExpr()->getType(), 975 DstType = E->getType(); 976 977 Value *Src = CGF.EmitScalarExpr(E->getSrcExpr()); 978 979 SrcType = CGF.getContext().getCanonicalType(SrcType); 980 DstType = CGF.getContext().getCanonicalType(DstType); 981 if (SrcType == DstType) return Src; 982 983 assert(SrcType->isVectorType() && 984 "ConvertVector source type must be a vector"); 985 assert(DstType->isVectorType() && 986 "ConvertVector destination type must be a vector"); 987 988 llvm::Type *SrcTy = Src->getType(); 989 llvm::Type *DstTy = ConvertType(DstType); 990 991 // Ignore conversions like int -> uint. 992 if (SrcTy == DstTy) 993 return Src; 994 995 QualType SrcEltType = SrcType->getAs<VectorType>()->getElementType(), 996 DstEltType = DstType->getAs<VectorType>()->getElementType(); 997 998 assert(SrcTy->isVectorTy() && 999 "ConvertVector source IR type must be a vector"); 1000 assert(DstTy->isVectorTy() && 1001 "ConvertVector destination IR type must be a vector"); 1002 1003 llvm::Type *SrcEltTy = SrcTy->getVectorElementType(), 1004 *DstEltTy = DstTy->getVectorElementType(); 1005 1006 if (DstEltType->isBooleanType()) { 1007 assert((SrcEltTy->isFloatingPointTy() || 1008 isa<llvm::IntegerType>(SrcEltTy)) && "Unknown boolean conversion"); 1009 1010 llvm::Value *Zero = llvm::Constant::getNullValue(SrcTy); 1011 if (SrcEltTy->isFloatingPointTy()) { 1012 return Builder.CreateFCmpUNE(Src, Zero, "tobool"); 1013 } else { 1014 return Builder.CreateICmpNE(Src, Zero, "tobool"); 1015 } 1016 } 1017 1018 // We have the arithmetic types: real int/float. 1019 Value *Res = NULL; 1020 1021 if (isa<llvm::IntegerType>(SrcEltTy)) { 1022 bool InputSigned = SrcEltType->isSignedIntegerOrEnumerationType(); 1023 if (isa<llvm::IntegerType>(DstEltTy)) 1024 Res = Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 1025 else if (InputSigned) 1026 Res = Builder.CreateSIToFP(Src, DstTy, "conv"); 1027 else 1028 Res = Builder.CreateUIToFP(Src, DstTy, "conv"); 1029 } else if (isa<llvm::IntegerType>(DstEltTy)) { 1030 assert(SrcEltTy->isFloatingPointTy() && "Unknown real conversion"); 1031 if (DstEltType->isSignedIntegerOrEnumerationType()) 1032 Res = Builder.CreateFPToSI(Src, DstTy, "conv"); 1033 else 1034 Res = Builder.CreateFPToUI(Src, DstTy, "conv"); 1035 } else { 1036 assert(SrcEltTy->isFloatingPointTy() && DstEltTy->isFloatingPointTy() && 1037 "Unknown real conversion"); 1038 if (DstEltTy->getTypeID() < SrcEltTy->getTypeID()) 1039 Res = Builder.CreateFPTrunc(Src, DstTy, "conv"); 1040 else 1041 Res = Builder.CreateFPExt(Src, DstTy, "conv"); 1042 } 1043 1044 return Res; 1045} 1046 1047Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { 1048 llvm::APSInt Value; 1049 if (E->EvaluateAsInt(Value, CGF.getContext(), Expr::SE_AllowSideEffects)) { 1050 if (E->isArrow()) 1051 CGF.EmitScalarExpr(E->getBase()); 1052 else 1053 EmitLValue(E->getBase()); 1054 return Builder.getInt(Value); 1055 } 1056 1057 return EmitLoadOfLValue(E); 1058} 1059 1060Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 1061 TestAndClearIgnoreResultAssign(); 1062 1063 // Emit subscript expressions in rvalue context's. For most cases, this just 1064 // loads the lvalue formed by the subscript expr. However, we have to be 1065 // careful, because the base of a vector subscript is occasionally an rvalue, 1066 // so we can't get it as an lvalue. 1067 if (!E->getBase()->getType()->isVectorType()) 1068 return EmitLoadOfLValue(E); 1069 1070 // Handle the vector case. The base must be a vector, the index must be an 1071 // integer value. 1072 Value *Base = Visit(E->getBase()); 1073 Value *Idx = Visit(E->getIdx()); 1074 QualType IdxTy = E->getIdx()->getType(); 1075 1076 if (CGF.SanOpts->ArrayBounds) 1077 CGF.EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, /*Accessed*/true); 1078 1079 bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType(); 1080 Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vecidxcast"); 1081 return Builder.CreateExtractElement(Base, Idx, "vecext"); 1082} 1083 1084static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, 1085 unsigned Off, llvm::Type *I32Ty) { 1086 int MV = SVI->getMaskValue(Idx); 1087 if (MV == -1) 1088 return llvm::UndefValue::get(I32Ty); 1089 return llvm::ConstantInt::get(I32Ty, Off+MV); 1090} 1091 1092Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) { 1093 bool Ignore = TestAndClearIgnoreResultAssign(); 1094 (void)Ignore; 1095 assert (Ignore == false && "init list ignored"); 1096 unsigned NumInitElements = E->getNumInits(); 1097 1098 if (E->hadArrayRangeDesignator()) 1099 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 1100 1101 llvm::VectorType *VType = 1102 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 1103 1104 if (!VType) { 1105 if (NumInitElements == 0) { 1106 // C++11 value-initialization for the scalar. 1107 return EmitNullValue(E->getType()); 1108 } 1109 // We have a scalar in braces. Just use the first element. 1110 return Visit(E->getInit(0)); 1111 } 1112 1113 unsigned ResElts = VType->getNumElements(); 1114 1115 // Loop over initializers collecting the Value for each, and remembering 1116 // whether the source was swizzle (ExtVectorElementExpr). This will allow 1117 // us to fold the shuffle for the swizzle into the shuffle for the vector 1118 // initializer, since LLVM optimizers generally do not want to touch 1119 // shuffles. 1120 unsigned CurIdx = 0; 1121 bool VIsUndefShuffle = false; 1122 llvm::Value *V = llvm::UndefValue::get(VType); 1123 for (unsigned i = 0; i != NumInitElements; ++i) { 1124 Expr *IE = E->getInit(i); 1125 Value *Init = Visit(IE); 1126 SmallVector<llvm::Constant*, 16> Args; 1127 1128 llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType()); 1129 1130 // Handle scalar elements. If the scalar initializer is actually one 1131 // element of a different vector of the same width, use shuffle instead of 1132 // extract+insert. 1133 if (!VVT) { 1134 if (isa<ExtVectorElementExpr>(IE)) { 1135 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init); 1136 1137 if (EI->getVectorOperandType()->getNumElements() == ResElts) { 1138 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand()); 1139 Value *LHS = 0, *RHS = 0; 1140 if (CurIdx == 0) { 1141 // insert into undef -> shuffle (src, undef) 1142 Args.push_back(C); 1143 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 1144 1145 LHS = EI->getVectorOperand(); 1146 RHS = V; 1147 VIsUndefShuffle = true; 1148 } else if (VIsUndefShuffle) { 1149 // insert into undefshuffle && size match -> shuffle (v, src) 1150 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V); 1151 for (unsigned j = 0; j != CurIdx; ++j) 1152 Args.push_back(getMaskElt(SVV, j, 0, CGF.Int32Ty)); 1153 Args.push_back(Builder.getInt32(ResElts + C->getZExtValue())); 1154 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 1155 1156 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 1157 RHS = EI->getVectorOperand(); 1158 VIsUndefShuffle = false; 1159 } 1160 if (!Args.empty()) { 1161 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 1162 V = Builder.CreateShuffleVector(LHS, RHS, Mask); 1163 ++CurIdx; 1164 continue; 1165 } 1166 } 1167 } 1168 V = Builder.CreateInsertElement(V, Init, Builder.getInt32(CurIdx), 1169 "vecinit"); 1170 VIsUndefShuffle = false; 1171 ++CurIdx; 1172 continue; 1173 } 1174 1175 unsigned InitElts = VVT->getNumElements(); 1176 1177 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's 1178 // input is the same width as the vector being constructed, generate an 1179 // optimized shuffle of the swizzle input into the result. 1180 unsigned Offset = (CurIdx == 0) ? 0 : ResElts; 1181 if (isa<ExtVectorElementExpr>(IE)) { 1182 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init); 1183 Value *SVOp = SVI->getOperand(0); 1184 llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType()); 1185 1186 if (OpTy->getNumElements() == ResElts) { 1187 for (unsigned j = 0; j != CurIdx; ++j) { 1188 // If the current vector initializer is a shuffle with undef, merge 1189 // this shuffle directly into it. 1190 if (VIsUndefShuffle) { 1191 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0, 1192 CGF.Int32Ty)); 1193 } else { 1194 Args.push_back(Builder.getInt32(j)); 1195 } 1196 } 1197 for (unsigned j = 0, je = InitElts; j != je; ++j) 1198 Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty)); 1199 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 1200 1201 if (VIsUndefShuffle) 1202 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 1203 1204 Init = SVOp; 1205 } 1206 } 1207 1208 // Extend init to result vector length, and then shuffle its contribution 1209 // to the vector initializer into V. 1210 if (Args.empty()) { 1211 for (unsigned j = 0; j != InitElts; ++j) 1212 Args.push_back(Builder.getInt32(j)); 1213 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 1214 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 1215 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), 1216 Mask, "vext"); 1217 1218 Args.clear(); 1219 for (unsigned j = 0; j != CurIdx; ++j) 1220 Args.push_back(Builder.getInt32(j)); 1221 for (unsigned j = 0; j != InitElts; ++j) 1222 Args.push_back(Builder.getInt32(j+Offset)); 1223 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 1224 } 1225 1226 // If V is undef, make sure it ends up on the RHS of the shuffle to aid 1227 // merging subsequent shuffles into this one. 1228 if (CurIdx == 0) 1229 std::swap(V, Init); 1230 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 1231 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); 1232 VIsUndefShuffle = isa<llvm::UndefValue>(Init); 1233 CurIdx += InitElts; 1234 } 1235 1236 // FIXME: evaluate codegen vs. shuffling against constant null vector. 1237 // Emit remaining default initializers. 1238 llvm::Type *EltTy = VType->getElementType(); 1239 1240 // Emit remaining default initializers 1241 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { 1242 Value *Idx = Builder.getInt32(CurIdx); 1243 llvm::Value *Init = llvm::Constant::getNullValue(EltTy); 1244 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 1245 } 1246 return V; 1247} 1248 1249static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { 1250 const Expr *E = CE->getSubExpr(); 1251 1252 if (CE->getCastKind() == CK_UncheckedDerivedToBase) 1253 return false; 1254 1255 if (isa<CXXThisExpr>(E)) { 1256 // We always assume that 'this' is never null. 1257 return false; 1258 } 1259 1260 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { 1261 // And that glvalue casts are never null. 1262 if (ICE->getValueKind() != VK_RValue) 1263 return false; 1264 } 1265 1266 return true; 1267} 1268 1269// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 1270// have to handle a more broad range of conversions than explicit casts, as they 1271// handle things like function to ptr-to-function decay etc. 1272Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) { 1273 Expr *E = CE->getSubExpr(); 1274 QualType DestTy = CE->getType(); 1275 CastKind Kind = CE->getCastKind(); 1276 1277 if (!DestTy->isVoidType()) 1278 TestAndClearIgnoreResultAssign(); 1279 1280 // Since almost all cast kinds apply to scalars, this switch doesn't have 1281 // a default case, so the compiler will warn on a missing case. The cases 1282 // are in the same order as in the CastKind enum. 1283 switch (Kind) { 1284 case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!"); 1285 case CK_BuiltinFnToFnPtr: 1286 llvm_unreachable("builtin functions are handled elsewhere"); 1287 1288 case CK_LValueBitCast: 1289 case CK_ObjCObjectLValueCast: { 1290 Value *V = EmitLValue(E).getAddress(); 1291 V = Builder.CreateBitCast(V, 1292 ConvertType(CGF.getContext().getPointerType(DestTy))); 1293 return EmitLoadOfLValue(CGF.MakeNaturalAlignAddrLValue(V, DestTy), 1294 CE->getExprLoc()); 1295 } 1296 1297 case CK_CPointerToObjCPointerCast: 1298 case CK_BlockPointerToObjCPointerCast: 1299 case CK_AnyPointerToBlockPointerCast: 1300 case CK_BitCast: { 1301 Value *Src = Visit(const_cast<Expr*>(E)); 1302 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 1303 } 1304 case CK_AtomicToNonAtomic: 1305 case CK_NonAtomicToAtomic: 1306 case CK_NoOp: 1307 case CK_UserDefinedConversion: 1308 return Visit(const_cast<Expr*>(E)); 1309 1310 case CK_BaseToDerived: { 1311 const CXXRecordDecl *DerivedClassDecl = DestTy->getPointeeCXXRecordDecl(); 1312 assert(DerivedClassDecl && "BaseToDerived arg isn't a C++ object pointer!"); 1313 1314 llvm::Value *V = Visit(E); 1315 1316 llvm::Value *Derived = 1317 CGF.GetAddressOfDerivedClass(V, DerivedClassDecl, 1318 CE->path_begin(), CE->path_end(), 1319 ShouldNullCheckClassCastValue(CE)); 1320 1321 // C++11 [expr.static.cast]p11: Behavior is undefined if a downcast is 1322 // performed and the object is not of the derived type. 1323 if (CGF.SanitizePerformTypeCheck) 1324 CGF.EmitTypeCheck(CodeGenFunction::TCK_DowncastPointer, CE->getExprLoc(), 1325 Derived, DestTy->getPointeeType()); 1326 1327 return Derived; 1328 } 1329 case CK_UncheckedDerivedToBase: 1330 case CK_DerivedToBase: { 1331 const CXXRecordDecl *DerivedClassDecl = 1332 E->getType()->getPointeeCXXRecordDecl(); 1333 assert(DerivedClassDecl && "DerivedToBase arg isn't a C++ object pointer!"); 1334 1335 return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl, 1336 CE->path_begin(), CE->path_end(), 1337 ShouldNullCheckClassCastValue(CE)); 1338 } 1339 case CK_Dynamic: { 1340 Value *V = Visit(const_cast<Expr*>(E)); 1341 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 1342 return CGF.EmitDynamicCast(V, DCE); 1343 } 1344 1345 case CK_ArrayToPointerDecay: { 1346 assert(E->getType()->isArrayType() && 1347 "Array to pointer decay must have array source type!"); 1348 1349 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 1350 1351 // Note that VLA pointers are always decayed, so we don't need to do 1352 // anything here. 1353 if (!E->getType()->isVariableArrayType()) { 1354 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 1355 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 1356 ->getElementType()) && 1357 "Expected pointer to array"); 1358 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 1359 } 1360 1361 // Make sure the array decay ends up being the right type. This matters if 1362 // the array type was of an incomplete type. 1363 return CGF.Builder.CreateBitCast(V, ConvertType(CE->getType())); 1364 } 1365 case CK_FunctionToPointerDecay: 1366 return EmitLValue(E).getAddress(); 1367 1368 case CK_NullToPointer: 1369 if (MustVisitNullValue(E)) 1370 (void) Visit(E); 1371 1372 return llvm::ConstantPointerNull::get( 1373 cast<llvm::PointerType>(ConvertType(DestTy))); 1374 1375 case CK_NullToMemberPointer: { 1376 if (MustVisitNullValue(E)) 1377 (void) Visit(E); 1378 1379 const MemberPointerType *MPT = CE->getType()->getAs<MemberPointerType>(); 1380 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 1381 } 1382 1383 case CK_ReinterpretMemberPointer: 1384 case CK_BaseToDerivedMemberPointer: 1385 case CK_DerivedToBaseMemberPointer: { 1386 Value *Src = Visit(E); 1387 1388 // Note that the AST doesn't distinguish between checked and 1389 // unchecked member pointer conversions, so we always have to 1390 // implement checked conversions here. This is inefficient when 1391 // actual control flow may be required in order to perform the 1392 // check, which it is for data member pointers (but not member 1393 // function pointers on Itanium and ARM). 1394 return CGF.CGM.getCXXABI().EmitMemberPointerConversion(CGF, CE, Src); 1395 } 1396 1397 case CK_ARCProduceObject: 1398 return CGF.EmitARCRetainScalarExpr(E); 1399 case CK_ARCConsumeObject: 1400 return CGF.EmitObjCConsumeObject(E->getType(), Visit(E)); 1401 case CK_ARCReclaimReturnedObject: { 1402 llvm::Value *value = Visit(E); 1403 value = CGF.EmitARCRetainAutoreleasedReturnValue(value); 1404 return CGF.EmitObjCConsumeObject(E->getType(), value); 1405 } 1406 case CK_ARCExtendBlockObject: 1407 return CGF.EmitARCExtendBlockObject(E); 1408 1409 case CK_CopyAndAutoreleaseBlockObject: 1410 return CGF.EmitBlockCopyAndAutorelease(Visit(E), E->getType()); 1411 1412 case CK_FloatingRealToComplex: 1413 case CK_FloatingComplexCast: 1414 case CK_IntegralRealToComplex: 1415 case CK_IntegralComplexCast: 1416 case CK_IntegralComplexToFloatingComplex: 1417 case CK_FloatingComplexToIntegralComplex: 1418 case CK_ConstructorConversion: 1419 case CK_ToUnion: 1420 llvm_unreachable("scalar cast to non-scalar value"); 1421 1422 case CK_LValueToRValue: 1423 assert(CGF.getContext().hasSameUnqualifiedType(E->getType(), DestTy)); 1424 assert(E->isGLValue() && "lvalue-to-rvalue applied to r-value!"); 1425 return Visit(const_cast<Expr*>(E)); 1426 1427 case CK_IntegralToPointer: { 1428 Value *Src = Visit(const_cast<Expr*>(E)); 1429 1430 // First, convert to the correct width so that we control the kind of 1431 // extension. 1432 llvm::Type *MiddleTy = CGF.IntPtrTy; 1433 bool InputSigned = E->getType()->isSignedIntegerOrEnumerationType(); 1434 llvm::Value* IntResult = 1435 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 1436 1437 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 1438 } 1439 case CK_PointerToIntegral: 1440 assert(!DestTy->isBooleanType() && "bool should use PointerToBool"); 1441 return Builder.CreatePtrToInt(Visit(E), ConvertType(DestTy)); 1442 1443 case CK_ToVoid: { 1444 CGF.EmitIgnoredExpr(E); 1445 return 0; 1446 } 1447 case CK_VectorSplat: { 1448 llvm::Type *DstTy = ConvertType(DestTy); 1449 Value *Elt = Visit(const_cast<Expr*>(E)); 1450 Elt = EmitScalarConversion(Elt, E->getType(), 1451 DestTy->getAs<VectorType>()->getElementType()); 1452 1453 // Splat the element across to all elements 1454 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 1455 return Builder.CreateVectorSplat(NumElements, Elt, "splat");; 1456 } 1457 1458 case CK_IntegralCast: 1459 case CK_IntegralToFloating: 1460 case CK_FloatingToIntegral: 1461 case CK_FloatingCast: 1462 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 1463 case CK_IntegralToBoolean: 1464 return EmitIntToBoolConversion(Visit(E)); 1465 case CK_PointerToBoolean: 1466 return EmitPointerToBoolConversion(Visit(E)); 1467 case CK_FloatingToBoolean: 1468 return EmitFloatToBoolConversion(Visit(E)); 1469 case CK_MemberPointerToBoolean: { 1470 llvm::Value *MemPtr = Visit(E); 1471 const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>(); 1472 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT); 1473 } 1474 1475 case CK_FloatingComplexToReal: 1476 case CK_IntegralComplexToReal: 1477 return CGF.EmitComplexExpr(E, false, true).first; 1478 1479 case CK_FloatingComplexToBoolean: 1480 case CK_IntegralComplexToBoolean: { 1481 CodeGenFunction::ComplexPairTy V = CGF.EmitComplexExpr(E); 1482 1483 // TODO: kill this function off, inline appropriate case here 1484 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 1485 } 1486 1487 case CK_ZeroToOCLEvent: { 1488 assert(DestTy->isEventT() && "CK_ZeroToOCLEvent cast on non event type"); 1489 return llvm::Constant::getNullValue(ConvertType(DestTy)); 1490 } 1491 1492 } 1493 1494 llvm_unreachable("unknown scalar cast"); 1495} 1496 1497Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 1498 CodeGenFunction::StmtExprEvaluation eval(CGF); 1499 llvm::Value *RetAlloca = CGF.EmitCompoundStmt(*E->getSubStmt(), 1500 !E->getType()->isVoidType()); 1501 if (!RetAlloca) 1502 return 0; 1503 return CGF.EmitLoadOfScalar(CGF.MakeAddrLValue(RetAlloca, E->getType()), 1504 E->getExprLoc()); 1505} 1506 1507//===----------------------------------------------------------------------===// 1508// Unary Operators 1509//===----------------------------------------------------------------------===// 1510 1511llvm::Value *ScalarExprEmitter:: 1512EmitAddConsiderOverflowBehavior(const UnaryOperator *E, 1513 llvm::Value *InVal, 1514 llvm::Value *NextVal, bool IsInc) { 1515 switch (CGF.getLangOpts().getSignedOverflowBehavior()) { 1516 case LangOptions::SOB_Defined: 1517 return Builder.CreateAdd(InVal, NextVal, IsInc ? "inc" : "dec"); 1518 case LangOptions::SOB_Undefined: 1519 if (!CGF.SanOpts->SignedIntegerOverflow) 1520 return Builder.CreateNSWAdd(InVal, NextVal, IsInc ? "inc" : "dec"); 1521 // Fall through. 1522 case LangOptions::SOB_Trapping: 1523 BinOpInfo BinOp; 1524 BinOp.LHS = InVal; 1525 BinOp.RHS = NextVal; 1526 BinOp.Ty = E->getType(); 1527 BinOp.Opcode = BO_Add; 1528 BinOp.FPContractable = false; 1529 BinOp.E = E; 1530 return EmitOverflowCheckedBinOp(BinOp); 1531 } 1532 llvm_unreachable("Unknown SignedOverflowBehaviorTy"); 1533} 1534 1535llvm::Value * 1536ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 1537 bool isInc, bool isPre) { 1538 1539 QualType type = E->getSubExpr()->getType(); 1540 llvm::PHINode *atomicPHI = 0; 1541 llvm::Value *value; 1542 llvm::Value *input; 1543 1544 int amount = (isInc ? 1 : -1); 1545 1546 if (const AtomicType *atomicTy = type->getAs<AtomicType>()) { 1547 type = atomicTy->getValueType(); 1548 if (isInc && type->isBooleanType()) { 1549 llvm::Value *True = CGF.EmitToMemory(Builder.getTrue(), type); 1550 if (isPre) { 1551 Builder.Insert(new llvm::StoreInst(True, 1552 LV.getAddress(), LV.isVolatileQualified(), 1553 LV.getAlignment().getQuantity(), 1554 llvm::SequentiallyConsistent)); 1555 return Builder.getTrue(); 1556 } 1557 // For atomic bool increment, we just store true and return it for 1558 // preincrement, do an atomic swap with true for postincrement 1559 return Builder.CreateAtomicRMW(llvm::AtomicRMWInst::Xchg, 1560 LV.getAddress(), True, llvm::SequentiallyConsistent); 1561 } 1562 // Special case for atomic increment / decrement on integers, emit 1563 // atomicrmw instructions. We skip this if we want to be doing overflow 1564 // checking, and fall into the slow path with the atomic cmpxchg loop. 1565 if (!type->isBooleanType() && type->isIntegerType() && 1566 !(type->isUnsignedIntegerType() && 1567 CGF.SanOpts->UnsignedIntegerOverflow) && 1568 CGF.getLangOpts().getSignedOverflowBehavior() != 1569 LangOptions::SOB_Trapping) { 1570 llvm::AtomicRMWInst::BinOp aop = isInc ? llvm::AtomicRMWInst::Add : 1571 llvm::AtomicRMWInst::Sub; 1572 llvm::Instruction::BinaryOps op = isInc ? llvm::Instruction::Add : 1573 llvm::Instruction::Sub; 1574 llvm::Value *amt = CGF.EmitToMemory( 1575 llvm::ConstantInt::get(ConvertType(type), 1, true), type); 1576 llvm::Value *old = Builder.CreateAtomicRMW(aop, 1577 LV.getAddress(), amt, llvm::SequentiallyConsistent); 1578 return isPre ? Builder.CreateBinOp(op, old, amt) : old; 1579 } 1580 value = EmitLoadOfLValue(LV, E->getExprLoc()); 1581 input = value; 1582 // For every other atomic operation, we need to emit a load-op-cmpxchg loop 1583 llvm::BasicBlock *startBB = Builder.GetInsertBlock(); 1584 llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn); 1585 value = CGF.EmitToMemory(value, type); 1586 Builder.CreateBr(opBB); 1587 Builder.SetInsertPoint(opBB); 1588 atomicPHI = Builder.CreatePHI(value->getType(), 2); 1589 atomicPHI->addIncoming(value, startBB); 1590 value = atomicPHI; 1591 } else { 1592 value = EmitLoadOfLValue(LV, E->getExprLoc()); 1593 input = value; 1594 } 1595 1596 // Special case of integer increment that we have to check first: bool++. 1597 // Due to promotion rules, we get: 1598 // bool++ -> bool = bool + 1 1599 // -> bool = (int)bool + 1 1600 // -> bool = ((int)bool + 1 != 0) 1601 // An interesting aspect of this is that increment is always true. 1602 // Decrement does not have this property. 1603 if (isInc && type->isBooleanType()) { 1604 value = Builder.getTrue(); 1605 1606 // Most common case by far: integer increment. 1607 } else if (type->isIntegerType()) { 1608 1609 llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount, true); 1610 1611 // Note that signed integer inc/dec with width less than int can't 1612 // overflow because of promotion rules; we're just eliding a few steps here. 1613 if (value->getType()->getPrimitiveSizeInBits() >= 1614 CGF.IntTy->getBitWidth() && 1615 type->isSignedIntegerOrEnumerationType()) { 1616 value = EmitAddConsiderOverflowBehavior(E, value, amt, isInc); 1617 } else if (value->getType()->getPrimitiveSizeInBits() >= 1618 CGF.IntTy->getBitWidth() && type->isUnsignedIntegerType() && 1619 CGF.SanOpts->UnsignedIntegerOverflow) { 1620 BinOpInfo BinOp; 1621 BinOp.LHS = value; 1622 BinOp.RHS = llvm::ConstantInt::get(value->getType(), 1, false); 1623 BinOp.Ty = E->getType(); 1624 BinOp.Opcode = isInc ? BO_Add : BO_Sub; 1625 BinOp.FPContractable = false; 1626 BinOp.E = E; 1627 value = EmitOverflowCheckedBinOp(BinOp); 1628 } else 1629 value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec"); 1630 1631 // Next most common: pointer increment. 1632 } else if (const PointerType *ptr = type->getAs<PointerType>()) { 1633 QualType type = ptr->getPointeeType(); 1634 1635 // VLA types don't have constant size. 1636 if (const VariableArrayType *vla 1637 = CGF.getContext().getAsVariableArrayType(type)) { 1638 llvm::Value *numElts = CGF.getVLASize(vla).first; 1639 if (!isInc) numElts = Builder.CreateNSWNeg(numElts, "vla.negsize"); 1640 if (CGF.getLangOpts().isSignedOverflowDefined()) 1641 value = Builder.CreateGEP(value, numElts, "vla.inc"); 1642 else 1643 value = Builder.CreateInBoundsGEP(value, numElts, "vla.inc"); 1644 1645 // Arithmetic on function pointers (!) is just +-1. 1646 } else if (type->isFunctionType()) { 1647 llvm::Value *amt = Builder.getInt32(amount); 1648 1649 value = CGF.EmitCastToVoidPtr(value); 1650 if (CGF.getLangOpts().isSignedOverflowDefined()) 1651 value = Builder.CreateGEP(value, amt, "incdec.funcptr"); 1652 else 1653 value = Builder.CreateInBoundsGEP(value, amt, "incdec.funcptr"); 1654 value = Builder.CreateBitCast(value, input->getType()); 1655 1656 // For everything else, we can just do a simple increment. 1657 } else { 1658 llvm::Value *amt = Builder.getInt32(amount); 1659 if (CGF.getLangOpts().isSignedOverflowDefined()) 1660 value = Builder.CreateGEP(value, amt, "incdec.ptr"); 1661 else 1662 value = Builder.CreateInBoundsGEP(value, amt, "incdec.ptr"); 1663 } 1664 1665 // Vector increment/decrement. 1666 } else if (type->isVectorType()) { 1667 if (type->hasIntegerRepresentation()) { 1668 llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount); 1669 1670 value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec"); 1671 } else { 1672 value = Builder.CreateFAdd( 1673 value, 1674 llvm::ConstantFP::get(value->getType(), amount), 1675 isInc ? "inc" : "dec"); 1676 } 1677 1678 // Floating point. 1679 } else if (type->isRealFloatingType()) { 1680 // Add the inc/dec to the real part. 1681 llvm::Value *amt; 1682 1683 if (type->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) { 1684 // Another special case: half FP increment should be done via float 1685 value = 1686 Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16), 1687 input); 1688 } 1689 1690 if (value->getType()->isFloatTy()) 1691 amt = llvm::ConstantFP::get(VMContext, 1692 llvm::APFloat(static_cast<float>(amount))); 1693 else if (value->getType()->isDoubleTy()) 1694 amt = llvm::ConstantFP::get(VMContext, 1695 llvm::APFloat(static_cast<double>(amount))); 1696 else { 1697 llvm::APFloat F(static_cast<float>(amount)); 1698 bool ignored; 1699 F.convert(CGF.getTarget().getLongDoubleFormat(), 1700 llvm::APFloat::rmTowardZero, &ignored); 1701 amt = llvm::ConstantFP::get(VMContext, F); 1702 } 1703 value = Builder.CreateFAdd(value, amt, isInc ? "inc" : "dec"); 1704 1705 if (type->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) 1706 value = 1707 Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16), 1708 value); 1709 1710 // Objective-C pointer types. 1711 } else { 1712 const ObjCObjectPointerType *OPT = type->castAs<ObjCObjectPointerType>(); 1713 value = CGF.EmitCastToVoidPtr(value); 1714 1715 CharUnits size = CGF.getContext().getTypeSizeInChars(OPT->getObjectType()); 1716 if (!isInc) size = -size; 1717 llvm::Value *sizeValue = 1718 llvm::ConstantInt::get(CGF.SizeTy, size.getQuantity()); 1719 1720 if (CGF.getLangOpts().isSignedOverflowDefined()) 1721 value = Builder.CreateGEP(value, sizeValue, "incdec.objptr"); 1722 else 1723 value = Builder.CreateInBoundsGEP(value, sizeValue, "incdec.objptr"); 1724 value = Builder.CreateBitCast(value, input->getType()); 1725 } 1726 1727 if (atomicPHI) { 1728 llvm::BasicBlock *opBB = Builder.GetInsertBlock(); 1729 llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn); 1730 llvm::Value *old = Builder.CreateAtomicCmpXchg(LV.getAddress(), atomicPHI, 1731 CGF.EmitToMemory(value, type), llvm::SequentiallyConsistent); 1732 atomicPHI->addIncoming(old, opBB); 1733 llvm::Value *success = Builder.CreateICmpEQ(old, atomicPHI); 1734 Builder.CreateCondBr(success, contBB, opBB); 1735 Builder.SetInsertPoint(contBB); 1736 return isPre ? value : input; 1737 } 1738 1739 // Store the updated result through the lvalue. 1740 if (LV.isBitField()) 1741 CGF.EmitStoreThroughBitfieldLValue(RValue::get(value), LV, &value); 1742 else 1743 CGF.EmitStoreThroughLValue(RValue::get(value), LV); 1744 1745 // If this is a postinc, return the value read from memory, otherwise use the 1746 // updated value. 1747 return isPre ? value : input; 1748} 1749 1750 1751 1752Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1753 TestAndClearIgnoreResultAssign(); 1754 // Emit unary minus with EmitSub so we handle overflow cases etc. 1755 BinOpInfo BinOp; 1756 BinOp.RHS = Visit(E->getSubExpr()); 1757 1758 if (BinOp.RHS->getType()->isFPOrFPVectorTy()) 1759 BinOp.LHS = llvm::ConstantFP::getZeroValueForNegation(BinOp.RHS->getType()); 1760 else 1761 BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType()); 1762 BinOp.Ty = E->getType(); 1763 BinOp.Opcode = BO_Sub; 1764 BinOp.FPContractable = false; 1765 BinOp.E = E; 1766 return EmitSub(BinOp); 1767} 1768 1769Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1770 TestAndClearIgnoreResultAssign(); 1771 Value *Op = Visit(E->getSubExpr()); 1772 return Builder.CreateNot(Op, "neg"); 1773} 1774 1775Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1776 // Perform vector logical not on comparison with zero vector. 1777 if (E->getType()->isExtVectorType()) { 1778 Value *Oper = Visit(E->getSubExpr()); 1779 Value *Zero = llvm::Constant::getNullValue(Oper->getType()); 1780 Value *Result; 1781 if (Oper->getType()->isFPOrFPVectorTy()) 1782 Result = Builder.CreateFCmp(llvm::CmpInst::FCMP_OEQ, Oper, Zero, "cmp"); 1783 else 1784 Result = Builder.CreateICmp(llvm::CmpInst::ICMP_EQ, Oper, Zero, "cmp"); 1785 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 1786 } 1787 1788 // Compare operand to zero. 1789 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1790 1791 // Invert value. 1792 // TODO: Could dynamically modify easy computations here. For example, if 1793 // the operand is an icmp ne, turn into icmp eq. 1794 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1795 1796 // ZExt result to the expr type. 1797 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1798} 1799 1800Value *ScalarExprEmitter::VisitOffsetOfExpr(OffsetOfExpr *E) { 1801 // Try folding the offsetof to a constant. 1802 llvm::APSInt Value; 1803 if (E->EvaluateAsInt(Value, CGF.getContext())) 1804 return Builder.getInt(Value); 1805 1806 // Loop over the components of the offsetof to compute the value. 1807 unsigned n = E->getNumComponents(); 1808 llvm::Type* ResultType = ConvertType(E->getType()); 1809 llvm::Value* Result = llvm::Constant::getNullValue(ResultType); 1810 QualType CurrentType = E->getTypeSourceInfo()->getType(); 1811 for (unsigned i = 0; i != n; ++i) { 1812 OffsetOfExpr::OffsetOfNode ON = E->getComponent(i); 1813 llvm::Value *Offset = 0; 1814 switch (ON.getKind()) { 1815 case OffsetOfExpr::OffsetOfNode::Array: { 1816 // Compute the index 1817 Expr *IdxExpr = E->getIndexExpr(ON.getArrayExprIndex()); 1818 llvm::Value* Idx = CGF.EmitScalarExpr(IdxExpr); 1819 bool IdxSigned = IdxExpr->getType()->isSignedIntegerOrEnumerationType(); 1820 Idx = Builder.CreateIntCast(Idx, ResultType, IdxSigned, "conv"); 1821 1822 // Save the element type 1823 CurrentType = 1824 CGF.getContext().getAsArrayType(CurrentType)->getElementType(); 1825 1826 // Compute the element size 1827 llvm::Value* ElemSize = llvm::ConstantInt::get(ResultType, 1828 CGF.getContext().getTypeSizeInChars(CurrentType).getQuantity()); 1829 1830 // Multiply out to compute the result 1831 Offset = Builder.CreateMul(Idx, ElemSize); 1832 break; 1833 } 1834 1835 case OffsetOfExpr::OffsetOfNode::Field: { 1836 FieldDecl *MemberDecl = ON.getField(); 1837 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1838 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1839 1840 // Compute the index of the field in its parent. 1841 unsigned i = 0; 1842 // FIXME: It would be nice if we didn't have to loop here! 1843 for (RecordDecl::field_iterator Field = RD->field_begin(), 1844 FieldEnd = RD->field_end(); 1845 Field != FieldEnd; ++Field, ++i) { 1846 if (*Field == MemberDecl) 1847 break; 1848 } 1849 assert(i < RL.getFieldCount() && "offsetof field in wrong type"); 1850 1851 // Compute the offset to the field 1852 int64_t OffsetInt = RL.getFieldOffset(i) / 1853 CGF.getContext().getCharWidth(); 1854 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1855 1856 // Save the element type. 1857 CurrentType = MemberDecl->getType(); 1858 break; 1859 } 1860 1861 case OffsetOfExpr::OffsetOfNode::Identifier: 1862 llvm_unreachable("dependent __builtin_offsetof"); 1863 1864 case OffsetOfExpr::OffsetOfNode::Base: { 1865 if (ON.getBase()->isVirtual()) { 1866 CGF.ErrorUnsupported(E, "virtual base in offsetof"); 1867 continue; 1868 } 1869 1870 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1871 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1872 1873 // Save the element type. 1874 CurrentType = ON.getBase()->getType(); 1875 1876 // Compute the offset to the base. 1877 const RecordType *BaseRT = CurrentType->getAs<RecordType>(); 1878 CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl()); 1879 CharUnits OffsetInt = RL.getBaseClassOffset(BaseRD); 1880 Offset = llvm::ConstantInt::get(ResultType, OffsetInt.getQuantity()); 1881 break; 1882 } 1883 } 1884 Result = Builder.CreateAdd(Result, Offset); 1885 } 1886 return Result; 1887} 1888 1889/// VisitUnaryExprOrTypeTraitExpr - Return the size or alignment of the type of 1890/// argument of the sizeof expression as an integer. 1891Value * 1892ScalarExprEmitter::VisitUnaryExprOrTypeTraitExpr( 1893 const UnaryExprOrTypeTraitExpr *E) { 1894 QualType TypeToSize = E->getTypeOfArgument(); 1895 if (E->getKind() == UETT_SizeOf) { 1896 if (const VariableArrayType *VAT = 1897 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1898 if (E->isArgumentType()) { 1899 // sizeof(type) - make sure to emit the VLA size. 1900 CGF.EmitVariablyModifiedType(TypeToSize); 1901 } else { 1902 // C99 6.5.3.4p2: If the argument is an expression of type 1903 // VLA, it is evaluated. 1904 CGF.EmitIgnoredExpr(E->getArgumentExpr()); 1905 } 1906 1907 QualType eltType; 1908 llvm::Value *numElts; 1909 llvm::tie(numElts, eltType) = CGF.getVLASize(VAT); 1910 1911 llvm::Value *size = numElts; 1912 1913 // Scale the number of non-VLA elements by the non-VLA element size. 1914 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType); 1915 if (!eltSize.isOne()) 1916 size = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), numElts); 1917 1918 return size; 1919 } 1920 } 1921 1922 // If this isn't sizeof(vla), the result must be constant; use the constant 1923 // folding logic so we don't have to duplicate it here. 1924 return Builder.getInt(E->EvaluateKnownConstInt(CGF.getContext())); 1925} 1926 1927Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1928 Expr *Op = E->getSubExpr(); 1929 if (Op->getType()->isAnyComplexType()) { 1930 // If it's an l-value, load through the appropriate subobject l-value. 1931 // Note that we have to ask E because Op might be an l-value that 1932 // this won't work for, e.g. an Obj-C property. 1933 if (E->isGLValue()) 1934 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E), 1935 E->getExprLoc()).getScalarVal(); 1936 1937 // Otherwise, calculate and project. 1938 return CGF.EmitComplexExpr(Op, false, true).first; 1939 } 1940 1941 return Visit(Op); 1942} 1943 1944Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1945 Expr *Op = E->getSubExpr(); 1946 if (Op->getType()->isAnyComplexType()) { 1947 // If it's an l-value, load through the appropriate subobject l-value. 1948 // Note that we have to ask E because Op might be an l-value that 1949 // this won't work for, e.g. an Obj-C property. 1950 if (Op->isGLValue()) 1951 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E), 1952 E->getExprLoc()).getScalarVal(); 1953 1954 // Otherwise, calculate and project. 1955 return CGF.EmitComplexExpr(Op, true, false).second; 1956 } 1957 1958 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1959 // effects are evaluated, but not the actual value. 1960 if (Op->isGLValue()) 1961 CGF.EmitLValue(Op); 1962 else 1963 CGF.EmitScalarExpr(Op, true); 1964 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1965} 1966 1967//===----------------------------------------------------------------------===// 1968// Binary Operators 1969//===----------------------------------------------------------------------===// 1970 1971BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1972 TestAndClearIgnoreResultAssign(); 1973 BinOpInfo Result; 1974 Result.LHS = Visit(E->getLHS()); 1975 Result.RHS = Visit(E->getRHS()); 1976 Result.Ty = E->getType(); 1977 Result.Opcode = E->getOpcode(); 1978 Result.FPContractable = E->isFPContractable(); 1979 Result.E = E; 1980 return Result; 1981} 1982 1983LValue ScalarExprEmitter::EmitCompoundAssignLValue( 1984 const CompoundAssignOperator *E, 1985 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &), 1986 Value *&Result) { 1987 QualType LHSTy = E->getLHS()->getType(); 1988 BinOpInfo OpInfo; 1989 1990 if (E->getComputationResultType()->isAnyComplexType()) 1991 return CGF.EmitScalarCompooundAssignWithComplex(E, Result); 1992 1993 // Emit the RHS first. __block variables need to have the rhs evaluated 1994 // first, plus this should improve codegen a little. 1995 OpInfo.RHS = Visit(E->getRHS()); 1996 OpInfo.Ty = E->getComputationResultType(); 1997 OpInfo.Opcode = E->getOpcode(); 1998 OpInfo.FPContractable = false; 1999 OpInfo.E = E; 2000 // Load/convert the LHS. 2001 LValue LHSLV = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store); 2002 2003 llvm::PHINode *atomicPHI = 0; 2004 if (const AtomicType *atomicTy = LHSTy->getAs<AtomicType>()) { 2005 QualType type = atomicTy->getValueType(); 2006 if (!type->isBooleanType() && type->isIntegerType() && 2007 !(type->isUnsignedIntegerType() && 2008 CGF.SanOpts->UnsignedIntegerOverflow) && 2009 CGF.getLangOpts().getSignedOverflowBehavior() != 2010 LangOptions::SOB_Trapping) { 2011 llvm::AtomicRMWInst::BinOp aop = llvm::AtomicRMWInst::BAD_BINOP; 2012 switch (OpInfo.Opcode) { 2013 // We don't have atomicrmw operands for *, %, /, <<, >> 2014 case BO_MulAssign: case BO_DivAssign: 2015 case BO_RemAssign: 2016 case BO_ShlAssign: 2017 case BO_ShrAssign: 2018 break; 2019 case BO_AddAssign: 2020 aop = llvm::AtomicRMWInst::Add; 2021 break; 2022 case BO_SubAssign: 2023 aop = llvm::AtomicRMWInst::Sub; 2024 break; 2025 case BO_AndAssign: 2026 aop = llvm::AtomicRMWInst::And; 2027 break; 2028 case BO_XorAssign: 2029 aop = llvm::AtomicRMWInst::Xor; 2030 break; 2031 case BO_OrAssign: 2032 aop = llvm::AtomicRMWInst::Or; 2033 break; 2034 default: 2035 llvm_unreachable("Invalid compound assignment type"); 2036 } 2037 if (aop != llvm::AtomicRMWInst::BAD_BINOP) { 2038 llvm::Value *amt = CGF.EmitToMemory(EmitScalarConversion(OpInfo.RHS, 2039 E->getRHS()->getType(), LHSTy), LHSTy); 2040 Builder.CreateAtomicRMW(aop, LHSLV.getAddress(), amt, 2041 llvm::SequentiallyConsistent); 2042 return LHSLV; 2043 } 2044 } 2045 // FIXME: For floating point types, we should be saving and restoring the 2046 // floating point environment in the loop. 2047 llvm::BasicBlock *startBB = Builder.GetInsertBlock(); 2048 llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn); 2049 OpInfo.LHS = EmitLoadOfLValue(LHSLV, E->getExprLoc()); 2050 OpInfo.LHS = CGF.EmitToMemory(OpInfo.LHS, type); 2051 Builder.CreateBr(opBB); 2052 Builder.SetInsertPoint(opBB); 2053 atomicPHI = Builder.CreatePHI(OpInfo.LHS->getType(), 2); 2054 atomicPHI->addIncoming(OpInfo.LHS, startBB); 2055 OpInfo.LHS = atomicPHI; 2056 } 2057 else 2058 OpInfo.LHS = EmitLoadOfLValue(LHSLV, E->getExprLoc()); 2059 2060 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 2061 E->getComputationLHSType()); 2062 2063 // Expand the binary operator. 2064 Result = (this->*Func)(OpInfo); 2065 2066 // Convert the result back to the LHS type. 2067 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 2068 2069 if (atomicPHI) { 2070 llvm::BasicBlock *opBB = Builder.GetInsertBlock(); 2071 llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn); 2072 llvm::Value *old = Builder.CreateAtomicCmpXchg(LHSLV.getAddress(), atomicPHI, 2073 CGF.EmitToMemory(Result, LHSTy), llvm::SequentiallyConsistent); 2074 atomicPHI->addIncoming(old, opBB); 2075 llvm::Value *success = Builder.CreateICmpEQ(old, atomicPHI); 2076 Builder.CreateCondBr(success, contBB, opBB); 2077 Builder.SetInsertPoint(contBB); 2078 return LHSLV; 2079 } 2080 2081 // Store the result value into the LHS lvalue. Bit-fields are handled 2082 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 2083 // 'An assignment expression has the value of the left operand after the 2084 // assignment...'. 2085 if (LHSLV.isBitField()) 2086 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, &Result); 2087 else 2088 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV); 2089 2090 return LHSLV; 2091} 2092 2093Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 2094 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 2095 bool Ignore = TestAndClearIgnoreResultAssign(); 2096 Value *RHS; 2097 LValue LHS = EmitCompoundAssignLValue(E, Func, RHS); 2098 2099 // If the result is clearly ignored, return now. 2100 if (Ignore) 2101 return 0; 2102 2103 // The result of an assignment in C is the assigned r-value. 2104 if (!CGF.getLangOpts().CPlusPlus) 2105 return RHS; 2106 2107 // If the lvalue is non-volatile, return the computed value of the assignment. 2108 if (!LHS.isVolatileQualified()) 2109 return RHS; 2110 2111 // Otherwise, reload the value. 2112 return EmitLoadOfLValue(LHS, E->getExprLoc()); 2113} 2114 2115void ScalarExprEmitter::EmitUndefinedBehaviorIntegerDivAndRemCheck( 2116 const BinOpInfo &Ops, llvm::Value *Zero, bool isDiv) { 2117 llvm::Value *Cond = 0; 2118 2119 if (CGF.SanOpts->IntegerDivideByZero) 2120 Cond = Builder.CreateICmpNE(Ops.RHS, Zero); 2121 2122 if (CGF.SanOpts->SignedIntegerOverflow && 2123 Ops.Ty->hasSignedIntegerRepresentation()) { 2124 llvm::IntegerType *Ty = cast<llvm::IntegerType>(Zero->getType()); 2125 2126 llvm::Value *IntMin = 2127 Builder.getInt(llvm::APInt::getSignedMinValue(Ty->getBitWidth())); 2128 llvm::Value *NegOne = llvm::ConstantInt::get(Ty, -1ULL); 2129 2130 llvm::Value *LHSCmp = Builder.CreateICmpNE(Ops.LHS, IntMin); 2131 llvm::Value *RHSCmp = Builder.CreateICmpNE(Ops.RHS, NegOne); 2132 llvm::Value *Overflow = Builder.CreateOr(LHSCmp, RHSCmp, "or"); 2133 Cond = Cond ? Builder.CreateAnd(Cond, Overflow, "and") : Overflow; 2134 } 2135 2136 if (Cond) 2137 EmitBinOpCheck(Cond, Ops); 2138} 2139 2140Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 2141 if ((CGF.SanOpts->IntegerDivideByZero || 2142 CGF.SanOpts->SignedIntegerOverflow) && 2143 Ops.Ty->isIntegerType()) { 2144 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 2145 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, true); 2146 } else if (CGF.SanOpts->FloatDivideByZero && 2147 Ops.Ty->isRealFloatingType()) { 2148 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 2149 EmitBinOpCheck(Builder.CreateFCmpUNE(Ops.RHS, Zero), Ops); 2150 } 2151 2152 if (Ops.LHS->getType()->isFPOrFPVectorTy()) { 2153 llvm::Value *Val = Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 2154 if (CGF.getLangOpts().OpenCL) { 2155 // OpenCL 1.1 7.4: minimum accuracy of single precision / is 2.5ulp 2156 llvm::Type *ValTy = Val->getType(); 2157 if (ValTy->isFloatTy() || 2158 (isa<llvm::VectorType>(ValTy) && 2159 cast<llvm::VectorType>(ValTy)->getElementType()->isFloatTy())) 2160 CGF.SetFPAccuracy(Val, 2.5); 2161 } 2162 return Val; 2163 } 2164 else if (Ops.Ty->hasUnsignedIntegerRepresentation()) 2165 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 2166 else 2167 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 2168} 2169 2170Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 2171 // Rem in C can't be a floating point type: C99 6.5.5p2. 2172 if (CGF.SanOpts->IntegerDivideByZero) { 2173 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 2174 2175 if (Ops.Ty->isIntegerType()) 2176 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, false); 2177 } 2178 2179 if (Ops.Ty->hasUnsignedIntegerRepresentation()) 2180 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 2181 else 2182 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 2183} 2184 2185Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 2186 unsigned IID; 2187 unsigned OpID = 0; 2188 2189 bool isSigned = Ops.Ty->isSignedIntegerOrEnumerationType(); 2190 switch (Ops.Opcode) { 2191 case BO_Add: 2192 case BO_AddAssign: 2193 OpID = 1; 2194 IID = isSigned ? llvm::Intrinsic::sadd_with_overflow : 2195 llvm::Intrinsic::uadd_with_overflow; 2196 break; 2197 case BO_Sub: 2198 case BO_SubAssign: 2199 OpID = 2; 2200 IID = isSigned ? llvm::Intrinsic::ssub_with_overflow : 2201 llvm::Intrinsic::usub_with_overflow; 2202 break; 2203 case BO_Mul: 2204 case BO_MulAssign: 2205 OpID = 3; 2206 IID = isSigned ? llvm::Intrinsic::smul_with_overflow : 2207 llvm::Intrinsic::umul_with_overflow; 2208 break; 2209 default: 2210 llvm_unreachable("Unsupported operation for overflow detection"); 2211 } 2212 OpID <<= 1; 2213 if (isSigned) 2214 OpID |= 1; 2215 2216 llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 2217 2218 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, opTy); 2219 2220 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 2221 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 2222 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 2223 2224 // Handle overflow with llvm.trap if no custom handler has been specified. 2225 const std::string *handlerName = 2226 &CGF.getLangOpts().OverflowHandler; 2227 if (handlerName->empty()) { 2228 // If the signed-integer-overflow sanitizer is enabled, emit a call to its 2229 // runtime. Otherwise, this is a -ftrapv check, so just emit a trap. 2230 if (!isSigned || CGF.SanOpts->SignedIntegerOverflow) 2231 EmitBinOpCheck(Builder.CreateNot(overflow), Ops); 2232 else 2233 CGF.EmitTrapCheck(Builder.CreateNot(overflow)); 2234 return result; 2235 } 2236 2237 // Branch in case of overflow. 2238 llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); 2239 llvm::Function::iterator insertPt = initialBB; 2240 llvm::BasicBlock *continueBB = CGF.createBasicBlock("nooverflow", CGF.CurFn, 2241 llvm::next(insertPt)); 2242 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); 2243 2244 Builder.CreateCondBr(overflow, overflowBB, continueBB); 2245 2246 // If an overflow handler is set, then we want to call it and then use its 2247 // result, if it returns. 2248 Builder.SetInsertPoint(overflowBB); 2249 2250 // Get the overflow handler. 2251 llvm::Type *Int8Ty = CGF.Int8Ty; 2252 llvm::Type *argTypes[] = { CGF.Int64Ty, CGF.Int64Ty, Int8Ty, Int8Ty }; 2253 llvm::FunctionType *handlerTy = 2254 llvm::FunctionType::get(CGF.Int64Ty, argTypes, true); 2255 llvm::Value *handler = CGF.CGM.CreateRuntimeFunction(handlerTy, *handlerName); 2256 2257 // Sign extend the args to 64-bit, so that we can use the same handler for 2258 // all types of overflow. 2259 llvm::Value *lhs = Builder.CreateSExt(Ops.LHS, CGF.Int64Ty); 2260 llvm::Value *rhs = Builder.CreateSExt(Ops.RHS, CGF.Int64Ty); 2261 2262 // Call the handler with the two arguments, the operation, and the size of 2263 // the result. 2264 llvm::Value *handlerArgs[] = { 2265 lhs, 2266 rhs, 2267 Builder.getInt8(OpID), 2268 Builder.getInt8(cast<llvm::IntegerType>(opTy)->getBitWidth()) 2269 }; 2270 llvm::Value *handlerResult = 2271 CGF.EmitNounwindRuntimeCall(handler, handlerArgs); 2272 2273 // Truncate the result back to the desired size. 2274 handlerResult = Builder.CreateTrunc(handlerResult, opTy); 2275 Builder.CreateBr(continueBB); 2276 2277 Builder.SetInsertPoint(continueBB); 2278 llvm::PHINode *phi = Builder.CreatePHI(opTy, 2); 2279 phi->addIncoming(result, initialBB); 2280 phi->addIncoming(handlerResult, overflowBB); 2281 2282 return phi; 2283} 2284 2285/// Emit pointer + index arithmetic. 2286static Value *emitPointerArithmetic(CodeGenFunction &CGF, 2287 const BinOpInfo &op, 2288 bool isSubtraction) { 2289 // Must have binary (not unary) expr here. Unary pointer 2290 // increment/decrement doesn't use this path. 2291 const BinaryOperator *expr = cast<BinaryOperator>(op.E); 2292 2293 Value *pointer = op.LHS; 2294 Expr *pointerOperand = expr->getLHS(); 2295 Value *index = op.RHS; 2296 Expr *indexOperand = expr->getRHS(); 2297 2298 // In a subtraction, the LHS is always the pointer. 2299 if (!isSubtraction && !pointer->getType()->isPointerTy()) { 2300 std::swap(pointer, index); 2301 std::swap(pointerOperand, indexOperand); 2302 } 2303 2304 unsigned width = cast<llvm::IntegerType>(index->getType())->getBitWidth(); 2305 if (width != CGF.PointerWidthInBits) { 2306 // Zero-extend or sign-extend the pointer value according to 2307 // whether the index is signed or not. 2308 bool isSigned = indexOperand->getType()->isSignedIntegerOrEnumerationType(); 2309 index = CGF.Builder.CreateIntCast(index, CGF.PtrDiffTy, isSigned, 2310 "idx.ext"); 2311 } 2312 2313 // If this is subtraction, negate the index. 2314 if (isSubtraction) 2315 index = CGF.Builder.CreateNeg(index, "idx.neg"); 2316 2317 if (CGF.SanOpts->ArrayBounds) 2318 CGF.EmitBoundsCheck(op.E, pointerOperand, index, indexOperand->getType(), 2319 /*Accessed*/ false); 2320 2321 const PointerType *pointerType 2322 = pointerOperand->getType()->getAs<PointerType>(); 2323 if (!pointerType) { 2324 QualType objectType = pointerOperand->getType() 2325 ->castAs<ObjCObjectPointerType>() 2326 ->getPointeeType(); 2327 llvm::Value *objectSize 2328 = CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(objectType)); 2329 2330 index = CGF.Builder.CreateMul(index, objectSize); 2331 2332 Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy); 2333 result = CGF.Builder.CreateGEP(result, index, "add.ptr"); 2334 return CGF.Builder.CreateBitCast(result, pointer->getType()); 2335 } 2336 2337 QualType elementType = pointerType->getPointeeType(); 2338 if (const VariableArrayType *vla 2339 = CGF.getContext().getAsVariableArrayType(elementType)) { 2340 // The element count here is the total number of non-VLA elements. 2341 llvm::Value *numElements = CGF.getVLASize(vla).first; 2342 2343 // Effectively, the multiply by the VLA size is part of the GEP. 2344 // GEP indexes are signed, and scaling an index isn't permitted to 2345 // signed-overflow, so we use the same semantics for our explicit 2346 // multiply. We suppress this if overflow is not undefined behavior. 2347 if (CGF.getLangOpts().isSignedOverflowDefined()) { 2348 index = CGF.Builder.CreateMul(index, numElements, "vla.index"); 2349 pointer = CGF.Builder.CreateGEP(pointer, index, "add.ptr"); 2350 } else { 2351 index = CGF.Builder.CreateNSWMul(index, numElements, "vla.index"); 2352 pointer = CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr"); 2353 } 2354 return pointer; 2355 } 2356 2357 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 2358 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 2359 // future proof. 2360 if (elementType->isVoidType() || elementType->isFunctionType()) { 2361 Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy); 2362 result = CGF.Builder.CreateGEP(result, index, "add.ptr"); 2363 return CGF.Builder.CreateBitCast(result, pointer->getType()); 2364 } 2365 2366 if (CGF.getLangOpts().isSignedOverflowDefined()) 2367 return CGF.Builder.CreateGEP(pointer, index, "add.ptr"); 2368 2369 return CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr"); 2370} 2371 2372// Construct an fmuladd intrinsic to represent a fused mul-add of MulOp and 2373// Addend. Use negMul and negAdd to negate the first operand of the Mul or 2374// the add operand respectively. This allows fmuladd to represent a*b-c, or 2375// c-a*b. Patterns in LLVM should catch the negated forms and translate them to 2376// efficient operations. 2377static Value* buildFMulAdd(llvm::BinaryOperator *MulOp, Value *Addend, 2378 const CodeGenFunction &CGF, CGBuilderTy &Builder, 2379 bool negMul, bool negAdd) { 2380 assert(!(negMul && negAdd) && "Only one of negMul and negAdd should be set."); 2381 2382 Value *MulOp0 = MulOp->getOperand(0); 2383 Value *MulOp1 = MulOp->getOperand(1); 2384 if (negMul) { 2385 MulOp0 = 2386 Builder.CreateFSub( 2387 llvm::ConstantFP::getZeroValueForNegation(MulOp0->getType()), MulOp0, 2388 "neg"); 2389 } else if (negAdd) { 2390 Addend = 2391 Builder.CreateFSub( 2392 llvm::ConstantFP::getZeroValueForNegation(Addend->getType()), Addend, 2393 "neg"); 2394 } 2395 2396 Value *FMulAdd = 2397 Builder.CreateCall3( 2398 CGF.CGM.getIntrinsic(llvm::Intrinsic::fmuladd, Addend->getType()), 2399 MulOp0, MulOp1, Addend); 2400 MulOp->eraseFromParent(); 2401 2402 return FMulAdd; 2403} 2404 2405// Check whether it would be legal to emit an fmuladd intrinsic call to 2406// represent op and if so, build the fmuladd. 2407// 2408// Checks that (a) the operation is fusable, and (b) -ffp-contract=on. 2409// Does NOT check the type of the operation - it's assumed that this function 2410// will be called from contexts where it's known that the type is contractable. 2411static Value* tryEmitFMulAdd(const BinOpInfo &op, 2412 const CodeGenFunction &CGF, CGBuilderTy &Builder, 2413 bool isSub=false) { 2414 2415 assert((op.Opcode == BO_Add || op.Opcode == BO_AddAssign || 2416 op.Opcode == BO_Sub || op.Opcode == BO_SubAssign) && 2417 "Only fadd/fsub can be the root of an fmuladd."); 2418 2419 // Check whether this op is marked as fusable. 2420 if (!op.FPContractable) 2421 return 0; 2422 2423 // Check whether -ffp-contract=on. (If -ffp-contract=off/fast, fusing is 2424 // either disabled, or handled entirely by the LLVM backend). 2425 if (CGF.CGM.getCodeGenOpts().getFPContractMode() != CodeGenOptions::FPC_On) 2426 return 0; 2427 2428 // We have a potentially fusable op. Look for a mul on one of the operands. 2429 if (llvm::BinaryOperator* LHSBinOp = dyn_cast<llvm::BinaryOperator>(op.LHS)) { 2430 if (LHSBinOp->getOpcode() == llvm::Instruction::FMul) { 2431 assert(LHSBinOp->getNumUses() == 0 && 2432 "Operations with multiple uses shouldn't be contracted."); 2433 return buildFMulAdd(LHSBinOp, op.RHS, CGF, Builder, false, isSub); 2434 } 2435 } else if (llvm::BinaryOperator* RHSBinOp = 2436 dyn_cast<llvm::BinaryOperator>(op.RHS)) { 2437 if (RHSBinOp->getOpcode() == llvm::Instruction::FMul) { 2438 assert(RHSBinOp->getNumUses() == 0 && 2439 "Operations with multiple uses shouldn't be contracted."); 2440 return buildFMulAdd(RHSBinOp, op.LHS, CGF, Builder, isSub, false); 2441 } 2442 } 2443 2444 return 0; 2445} 2446 2447Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &op) { 2448 if (op.LHS->getType()->isPointerTy() || 2449 op.RHS->getType()->isPointerTy()) 2450 return emitPointerArithmetic(CGF, op, /*subtraction*/ false); 2451 2452 if (op.Ty->isSignedIntegerOrEnumerationType()) { 2453 switch (CGF.getLangOpts().getSignedOverflowBehavior()) { 2454 case LangOptions::SOB_Defined: 2455 return Builder.CreateAdd(op.LHS, op.RHS, "add"); 2456 case LangOptions::SOB_Undefined: 2457 if (!CGF.SanOpts->SignedIntegerOverflow) 2458 return Builder.CreateNSWAdd(op.LHS, op.RHS, "add"); 2459 // Fall through. 2460 case LangOptions::SOB_Trapping: 2461 return EmitOverflowCheckedBinOp(op); 2462 } 2463 } 2464 2465 if (op.Ty->isUnsignedIntegerType() && CGF.SanOpts->UnsignedIntegerOverflow) 2466 return EmitOverflowCheckedBinOp(op); 2467 2468 if (op.LHS->getType()->isFPOrFPVectorTy()) { 2469 // Try to form an fmuladd. 2470 if (Value *FMulAdd = tryEmitFMulAdd(op, CGF, Builder)) 2471 return FMulAdd; 2472 2473 return Builder.CreateFAdd(op.LHS, op.RHS, "add"); 2474 } 2475 2476 return Builder.CreateAdd(op.LHS, op.RHS, "add"); 2477} 2478 2479Value *ScalarExprEmitter::EmitSub(const BinOpInfo &op) { 2480 // The LHS is always a pointer if either side is. 2481 if (!op.LHS->getType()->isPointerTy()) { 2482 if (op.Ty->isSignedIntegerOrEnumerationType()) { 2483 switch (CGF.getLangOpts().getSignedOverflowBehavior()) { 2484 case LangOptions::SOB_Defined: 2485 return Builder.CreateSub(op.LHS, op.RHS, "sub"); 2486 case LangOptions::SOB_Undefined: 2487 if (!CGF.SanOpts->SignedIntegerOverflow) 2488 return Builder.CreateNSWSub(op.LHS, op.RHS, "sub"); 2489 // Fall through. 2490 case LangOptions::SOB_Trapping: 2491 return EmitOverflowCheckedBinOp(op); 2492 } 2493 } 2494 2495 if (op.Ty->isUnsignedIntegerType() && CGF.SanOpts->UnsignedIntegerOverflow) 2496 return EmitOverflowCheckedBinOp(op); 2497 2498 if (op.LHS->getType()->isFPOrFPVectorTy()) { 2499 // Try to form an fmuladd. 2500 if (Value *FMulAdd = tryEmitFMulAdd(op, CGF, Builder, true)) 2501 return FMulAdd; 2502 return Builder.CreateFSub(op.LHS, op.RHS, "sub"); 2503 } 2504 2505 return Builder.CreateSub(op.LHS, op.RHS, "sub"); 2506 } 2507 2508 // If the RHS is not a pointer, then we have normal pointer 2509 // arithmetic. 2510 if (!op.RHS->getType()->isPointerTy()) 2511 return emitPointerArithmetic(CGF, op, /*subtraction*/ true); 2512 2513 // Otherwise, this is a pointer subtraction. 2514 2515 // Do the raw subtraction part. 2516 llvm::Value *LHS 2517 = Builder.CreatePtrToInt(op.LHS, CGF.PtrDiffTy, "sub.ptr.lhs.cast"); 2518 llvm::Value *RHS 2519 = Builder.CreatePtrToInt(op.RHS, CGF.PtrDiffTy, "sub.ptr.rhs.cast"); 2520 Value *diffInChars = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 2521 2522 // Okay, figure out the element size. 2523 const BinaryOperator *expr = cast<BinaryOperator>(op.E); 2524 QualType elementType = expr->getLHS()->getType()->getPointeeType(); 2525 2526 llvm::Value *divisor = 0; 2527 2528 // For a variable-length array, this is going to be non-constant. 2529 if (const VariableArrayType *vla 2530 = CGF.getContext().getAsVariableArrayType(elementType)) { 2531 llvm::Value *numElements; 2532 llvm::tie(numElements, elementType) = CGF.getVLASize(vla); 2533 2534 divisor = numElements; 2535 2536 // Scale the number of non-VLA elements by the non-VLA element size. 2537 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(elementType); 2538 if (!eltSize.isOne()) 2539 divisor = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), divisor); 2540 2541 // For everything elese, we can just compute it, safe in the 2542 // assumption that Sema won't let anything through that we can't 2543 // safely compute the size of. 2544 } else { 2545 CharUnits elementSize; 2546 // Handle GCC extension for pointer arithmetic on void* and 2547 // function pointer types. 2548 if (elementType->isVoidType() || elementType->isFunctionType()) 2549 elementSize = CharUnits::One(); 2550 else 2551 elementSize = CGF.getContext().getTypeSizeInChars(elementType); 2552 2553 // Don't even emit the divide for element size of 1. 2554 if (elementSize.isOne()) 2555 return diffInChars; 2556 2557 divisor = CGF.CGM.getSize(elementSize); 2558 } 2559 2560 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 2561 // pointer difference in C is only defined in the case where both operands 2562 // are pointing to elements of an array. 2563 return Builder.CreateExactSDiv(diffInChars, divisor, "sub.ptr.div"); 2564} 2565 2566Value *ScalarExprEmitter::GetWidthMinusOneValue(Value* LHS,Value* RHS) { 2567 llvm::IntegerType *Ty; 2568 if (llvm::VectorType *VT = dyn_cast<llvm::VectorType>(LHS->getType())) 2569 Ty = cast<llvm::IntegerType>(VT->getElementType()); 2570 else 2571 Ty = cast<llvm::IntegerType>(LHS->getType()); 2572 return llvm::ConstantInt::get(RHS->getType(), Ty->getBitWidth() - 1); 2573} 2574 2575Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 2576 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 2577 // RHS to the same size as the LHS. 2578 Value *RHS = Ops.RHS; 2579 if (Ops.LHS->getType() != RHS->getType()) 2580 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 2581 2582 if (CGF.SanOpts->Shift && !CGF.getLangOpts().OpenCL && 2583 isa<llvm::IntegerType>(Ops.LHS->getType())) { 2584 llvm::Value *WidthMinusOne = GetWidthMinusOneValue(Ops.LHS, RHS); 2585 llvm::Value *Valid = Builder.CreateICmpULE(RHS, WidthMinusOne); 2586 2587 if (Ops.Ty->hasSignedIntegerRepresentation()) { 2588 llvm::BasicBlock *Orig = Builder.GetInsertBlock(); 2589 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 2590 llvm::BasicBlock *CheckBitsShifted = CGF.createBasicBlock("check"); 2591 Builder.CreateCondBr(Valid, CheckBitsShifted, Cont); 2592 2593 // Check whether we are shifting any non-zero bits off the top of the 2594 // integer. 2595 CGF.EmitBlock(CheckBitsShifted); 2596 llvm::Value *BitsShiftedOff = 2597 Builder.CreateLShr(Ops.LHS, 2598 Builder.CreateSub(WidthMinusOne, RHS, "shl.zeros", 2599 /*NUW*/true, /*NSW*/true), 2600 "shl.check"); 2601 if (CGF.getLangOpts().CPlusPlus) { 2602 // In C99, we are not permitted to shift a 1 bit into the sign bit. 2603 // Under C++11's rules, shifting a 1 bit into the sign bit is 2604 // OK, but shifting a 1 bit out of it is not. (C89 and C++03 don't 2605 // define signed left shifts, so we use the C99 and C++11 rules there). 2606 llvm::Value *One = llvm::ConstantInt::get(BitsShiftedOff->getType(), 1); 2607 BitsShiftedOff = Builder.CreateLShr(BitsShiftedOff, One); 2608 } 2609 llvm::Value *Zero = llvm::ConstantInt::get(BitsShiftedOff->getType(), 0); 2610 llvm::Value *SecondCheck = Builder.CreateICmpEQ(BitsShiftedOff, Zero); 2611 CGF.EmitBlock(Cont); 2612 llvm::PHINode *P = Builder.CreatePHI(Valid->getType(), 2); 2613 P->addIncoming(Valid, Orig); 2614 P->addIncoming(SecondCheck, CheckBitsShifted); 2615 Valid = P; 2616 } 2617 2618 EmitBinOpCheck(Valid, Ops); 2619 } 2620 // OpenCL 6.3j: shift values are effectively % word size of LHS. 2621 if (CGF.getLangOpts().OpenCL) 2622 RHS = Builder.CreateAnd(RHS, GetWidthMinusOneValue(Ops.LHS, RHS), "shl.mask"); 2623 2624 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 2625} 2626 2627Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 2628 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 2629 // RHS to the same size as the LHS. 2630 Value *RHS = Ops.RHS; 2631 if (Ops.LHS->getType() != RHS->getType()) 2632 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 2633 2634 if (CGF.SanOpts->Shift && !CGF.getLangOpts().OpenCL && 2635 isa<llvm::IntegerType>(Ops.LHS->getType())) 2636 EmitBinOpCheck(Builder.CreateICmpULE(RHS, GetWidthMinusOneValue(Ops.LHS, RHS)), Ops); 2637 2638 // OpenCL 6.3j: shift values are effectively % word size of LHS. 2639 if (CGF.getLangOpts().OpenCL) 2640 RHS = Builder.CreateAnd(RHS, GetWidthMinusOneValue(Ops.LHS, RHS), "shr.mask"); 2641 2642 if (Ops.Ty->hasUnsignedIntegerRepresentation()) 2643 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 2644 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 2645} 2646 2647enum IntrinsicType { VCMPEQ, VCMPGT }; 2648// return corresponding comparison intrinsic for given vector type 2649static llvm::Intrinsic::ID GetIntrinsic(IntrinsicType IT, 2650 BuiltinType::Kind ElemKind) { 2651 switch (ElemKind) { 2652 default: llvm_unreachable("unexpected element type"); 2653 case BuiltinType::Char_U: 2654 case BuiltinType::UChar: 2655 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p : 2656 llvm::Intrinsic::ppc_altivec_vcmpgtub_p; 2657 case BuiltinType::Char_S: 2658 case BuiltinType::SChar: 2659 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p : 2660 llvm::Intrinsic::ppc_altivec_vcmpgtsb_p; 2661 case BuiltinType::UShort: 2662 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p : 2663 llvm::Intrinsic::ppc_altivec_vcmpgtuh_p; 2664 case BuiltinType::Short: 2665 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p : 2666 llvm::Intrinsic::ppc_altivec_vcmpgtsh_p; 2667 case BuiltinType::UInt: 2668 case BuiltinType::ULong: 2669 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p : 2670 llvm::Intrinsic::ppc_altivec_vcmpgtuw_p; 2671 case BuiltinType::Int: 2672 case BuiltinType::Long: 2673 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p : 2674 llvm::Intrinsic::ppc_altivec_vcmpgtsw_p; 2675 case BuiltinType::Float: 2676 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpeqfp_p : 2677 llvm::Intrinsic::ppc_altivec_vcmpgtfp_p; 2678 } 2679} 2680 2681Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 2682 unsigned SICmpOpc, unsigned FCmpOpc) { 2683 TestAndClearIgnoreResultAssign(); 2684 Value *Result; 2685 QualType LHSTy = E->getLHS()->getType(); 2686 if (const MemberPointerType *MPT = LHSTy->getAs<MemberPointerType>()) { 2687 assert(E->getOpcode() == BO_EQ || 2688 E->getOpcode() == BO_NE); 2689 Value *LHS = CGF.EmitScalarExpr(E->getLHS()); 2690 Value *RHS = CGF.EmitScalarExpr(E->getRHS()); 2691 Result = CGF.CGM.getCXXABI().EmitMemberPointerComparison( 2692 CGF, LHS, RHS, MPT, E->getOpcode() == BO_NE); 2693 } else if (!LHSTy->isAnyComplexType()) { 2694 Value *LHS = Visit(E->getLHS()); 2695 Value *RHS = Visit(E->getRHS()); 2696 2697 // If AltiVec, the comparison results in a numeric type, so we use 2698 // intrinsics comparing vectors and giving 0 or 1 as a result 2699 if (LHSTy->isVectorType() && !E->getType()->isVectorType()) { 2700 // constants for mapping CR6 register bits to predicate result 2701 enum { CR6_EQ=0, CR6_EQ_REV, CR6_LT, CR6_LT_REV } CR6; 2702 2703 llvm::Intrinsic::ID ID = llvm::Intrinsic::not_intrinsic; 2704 2705 // in several cases vector arguments order will be reversed 2706 Value *FirstVecArg = LHS, 2707 *SecondVecArg = RHS; 2708 2709 QualType ElTy = LHSTy->getAs<VectorType>()->getElementType(); 2710 const BuiltinType *BTy = ElTy->getAs<BuiltinType>(); 2711 BuiltinType::Kind ElementKind = BTy->getKind(); 2712 2713 switch(E->getOpcode()) { 2714 default: llvm_unreachable("is not a comparison operation"); 2715 case BO_EQ: 2716 CR6 = CR6_LT; 2717 ID = GetIntrinsic(VCMPEQ, ElementKind); 2718 break; 2719 case BO_NE: 2720 CR6 = CR6_EQ; 2721 ID = GetIntrinsic(VCMPEQ, ElementKind); 2722 break; 2723 case BO_LT: 2724 CR6 = CR6_LT; 2725 ID = GetIntrinsic(VCMPGT, ElementKind); 2726 std::swap(FirstVecArg, SecondVecArg); 2727 break; 2728 case BO_GT: 2729 CR6 = CR6_LT; 2730 ID = GetIntrinsic(VCMPGT, ElementKind); 2731 break; 2732 case BO_LE: 2733 if (ElementKind == BuiltinType::Float) { 2734 CR6 = CR6_LT; 2735 ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p; 2736 std::swap(FirstVecArg, SecondVecArg); 2737 } 2738 else { 2739 CR6 = CR6_EQ; 2740 ID = GetIntrinsic(VCMPGT, ElementKind); 2741 } 2742 break; 2743 case BO_GE: 2744 if (ElementKind == BuiltinType::Float) { 2745 CR6 = CR6_LT; 2746 ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p; 2747 } 2748 else { 2749 CR6 = CR6_EQ; 2750 ID = GetIntrinsic(VCMPGT, ElementKind); 2751 std::swap(FirstVecArg, SecondVecArg); 2752 } 2753 break; 2754 } 2755 2756 Value *CR6Param = Builder.getInt32(CR6); 2757 llvm::Function *F = CGF.CGM.getIntrinsic(ID); 2758 Result = Builder.CreateCall3(F, CR6Param, FirstVecArg, SecondVecArg, ""); 2759 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 2760 } 2761 2762 if (LHS->getType()->isFPOrFPVectorTy()) { 2763 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 2764 LHS, RHS, "cmp"); 2765 } else if (LHSTy->hasSignedIntegerRepresentation()) { 2766 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 2767 LHS, RHS, "cmp"); 2768 } else { 2769 // Unsigned integers and pointers. 2770 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2771 LHS, RHS, "cmp"); 2772 } 2773 2774 // If this is a vector comparison, sign extend the result to the appropriate 2775 // vector integer type and return it (don't convert to bool). 2776 if (LHSTy->isVectorType()) 2777 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 2778 2779 } else { 2780 // Complex Comparison: can only be an equality comparison. 2781 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 2782 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 2783 2784 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 2785 2786 Value *ResultR, *ResultI; 2787 if (CETy->isRealFloatingType()) { 2788 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 2789 LHS.first, RHS.first, "cmp.r"); 2790 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 2791 LHS.second, RHS.second, "cmp.i"); 2792 } else { 2793 // Complex comparisons can only be equality comparisons. As such, signed 2794 // and unsigned opcodes are the same. 2795 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2796 LHS.first, RHS.first, "cmp.r"); 2797 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2798 LHS.second, RHS.second, "cmp.i"); 2799 } 2800 2801 if (E->getOpcode() == BO_EQ) { 2802 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 2803 } else { 2804 assert(E->getOpcode() == BO_NE && 2805 "Complex comparison other than == or != ?"); 2806 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 2807 } 2808 } 2809 2810 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 2811} 2812 2813Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 2814 bool Ignore = TestAndClearIgnoreResultAssign(); 2815 2816 Value *RHS; 2817 LValue LHS; 2818 2819 switch (E->getLHS()->getType().getObjCLifetime()) { 2820 case Qualifiers::OCL_Strong: 2821 llvm::tie(LHS, RHS) = CGF.EmitARCStoreStrong(E, Ignore); 2822 break; 2823 2824 case Qualifiers::OCL_Autoreleasing: 2825 llvm::tie(LHS,RHS) = CGF.EmitARCStoreAutoreleasing(E); 2826 break; 2827 2828 case Qualifiers::OCL_Weak: 2829 RHS = Visit(E->getRHS()); 2830 LHS = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store); 2831 RHS = CGF.EmitARCStoreWeak(LHS.getAddress(), RHS, Ignore); 2832 break; 2833 2834 // No reason to do any of these differently. 2835 case Qualifiers::OCL_None: 2836 case Qualifiers::OCL_ExplicitNone: 2837 // __block variables need to have the rhs evaluated first, plus 2838 // this should improve codegen just a little. 2839 RHS = Visit(E->getRHS()); 2840 LHS = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store); 2841 2842 // Store the value into the LHS. Bit-fields are handled specially 2843 // because the result is altered by the store, i.e., [C99 6.5.16p1] 2844 // 'An assignment expression has the value of the left operand after 2845 // the assignment...'. 2846 if (LHS.isBitField()) 2847 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, &RHS); 2848 else 2849 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS); 2850 } 2851 2852 // If the result is clearly ignored, return now. 2853 if (Ignore) 2854 return 0; 2855 2856 // The result of an assignment in C is the assigned r-value. 2857 if (!CGF.getLangOpts().CPlusPlus) 2858 return RHS; 2859 2860 // If the lvalue is non-volatile, return the computed value of the assignment. 2861 if (!LHS.isVolatileQualified()) 2862 return RHS; 2863 2864 // Otherwise, reload the value. 2865 return EmitLoadOfLValue(LHS, E->getExprLoc()); 2866} 2867 2868Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 2869 // Perform vector logical and on comparisons with zero vectors. 2870 if (E->getType()->isVectorType()) { 2871 Value *LHS = Visit(E->getLHS()); 2872 Value *RHS = Visit(E->getRHS()); 2873 Value *Zero = llvm::ConstantAggregateZero::get(LHS->getType()); 2874 if (LHS->getType()->isFPOrFPVectorTy()) { 2875 LHS = Builder.CreateFCmp(llvm::CmpInst::FCMP_UNE, LHS, Zero, "cmp"); 2876 RHS = Builder.CreateFCmp(llvm::CmpInst::FCMP_UNE, RHS, Zero, "cmp"); 2877 } else { 2878 LHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, LHS, Zero, "cmp"); 2879 RHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, RHS, Zero, "cmp"); 2880 } 2881 Value *And = Builder.CreateAnd(LHS, RHS); 2882 return Builder.CreateSExt(And, ConvertType(E->getType()), "sext"); 2883 } 2884 2885 llvm::Type *ResTy = ConvertType(E->getType()); 2886 2887 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 2888 // If we have 1 && X, just emit X without inserting the control flow. 2889 bool LHSCondVal; 2890 if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) { 2891 if (LHSCondVal) { // If we have 1 && X, just emit X. 2892 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2893 // ZExt result to int or bool. 2894 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 2895 } 2896 2897 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 2898 if (!CGF.ContainsLabel(E->getRHS())) 2899 return llvm::Constant::getNullValue(ResTy); 2900 } 2901 2902 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 2903 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 2904 2905 CodeGenFunction::ConditionalEvaluation eval(CGF); 2906 2907 // Branch on the LHS first. If it is false, go to the failure (cont) block. 2908 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 2909 2910 // Any edges into the ContBlock are now from an (indeterminate number of) 2911 // edges from this first condition. All of these values will be false. Start 2912 // setting up the PHI node in the Cont Block for this. 2913 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2, 2914 "", ContBlock); 2915 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 2916 PI != PE; ++PI) 2917 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 2918 2919 eval.begin(CGF); 2920 CGF.EmitBlock(RHSBlock); 2921 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2922 eval.end(CGF); 2923 2924 // Reaquire the RHS block, as there may be subblocks inserted. 2925 RHSBlock = Builder.GetInsertBlock(); 2926 2927 // Emit an unconditional branch from this block to ContBlock. Insert an entry 2928 // into the phi node for the edge with the value of RHSCond. 2929 if (CGF.getDebugInfo()) 2930 // There is no need to emit line number for unconditional branch. 2931 Builder.SetCurrentDebugLocation(llvm::DebugLoc()); 2932 CGF.EmitBlock(ContBlock); 2933 PN->addIncoming(RHSCond, RHSBlock); 2934 2935 // ZExt result to int. 2936 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); 2937} 2938 2939Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 2940 // Perform vector logical or on comparisons with zero vectors. 2941 if (E->getType()->isVectorType()) { 2942 Value *LHS = Visit(E->getLHS()); 2943 Value *RHS = Visit(E->getRHS()); 2944 Value *Zero = llvm::ConstantAggregateZero::get(LHS->getType()); 2945 if (LHS->getType()->isFPOrFPVectorTy()) { 2946 LHS = Builder.CreateFCmp(llvm::CmpInst::FCMP_UNE, LHS, Zero, "cmp"); 2947 RHS = Builder.CreateFCmp(llvm::CmpInst::FCMP_UNE, RHS, Zero, "cmp"); 2948 } else { 2949 LHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, LHS, Zero, "cmp"); 2950 RHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, RHS, Zero, "cmp"); 2951 } 2952 Value *Or = Builder.CreateOr(LHS, RHS); 2953 return Builder.CreateSExt(Or, ConvertType(E->getType()), "sext"); 2954 } 2955 2956 llvm::Type *ResTy = ConvertType(E->getType()); 2957 2958 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 2959 // If we have 0 || X, just emit X without inserting the control flow. 2960 bool LHSCondVal; 2961 if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) { 2962 if (!LHSCondVal) { // If we have 0 || X, just emit X. 2963 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2964 // ZExt result to int or bool. 2965 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 2966 } 2967 2968 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 2969 if (!CGF.ContainsLabel(E->getRHS())) 2970 return llvm::ConstantInt::get(ResTy, 1); 2971 } 2972 2973 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 2974 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 2975 2976 CodeGenFunction::ConditionalEvaluation eval(CGF); 2977 2978 // Branch on the LHS first. If it is true, go to the success (cont) block. 2979 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 2980 2981 // Any edges into the ContBlock are now from an (indeterminate number of) 2982 // edges from this first condition. All of these values will be true. Start 2983 // setting up the PHI node in the Cont Block for this. 2984 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2, 2985 "", ContBlock); 2986 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 2987 PI != PE; ++PI) 2988 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 2989 2990 eval.begin(CGF); 2991 2992 // Emit the RHS condition as a bool value. 2993 CGF.EmitBlock(RHSBlock); 2994 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2995 2996 eval.end(CGF); 2997 2998 // Reaquire the RHS block, as there may be subblocks inserted. 2999 RHSBlock = Builder.GetInsertBlock(); 3000 3001 // Emit an unconditional branch from this block to ContBlock. Insert an entry 3002 // into the phi node for the edge with the value of RHSCond. 3003 CGF.EmitBlock(ContBlock); 3004 PN->addIncoming(RHSCond, RHSBlock); 3005 3006 // ZExt result to int. 3007 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 3008} 3009 3010Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 3011 CGF.EmitIgnoredExpr(E->getLHS()); 3012 CGF.EnsureInsertPoint(); 3013 return Visit(E->getRHS()); 3014} 3015 3016//===----------------------------------------------------------------------===// 3017// Other Operators 3018//===----------------------------------------------------------------------===// 3019 3020/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 3021/// expression is cheap enough and side-effect-free enough to evaluate 3022/// unconditionally instead of conditionally. This is used to convert control 3023/// flow into selects in some cases. 3024static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 3025 CodeGenFunction &CGF) { 3026 // Anything that is an integer or floating point constant is fine. 3027 return E->IgnoreParens()->isEvaluatable(CGF.getContext()); 3028 3029 // Even non-volatile automatic variables can't be evaluated unconditionally. 3030 // Referencing a thread_local may cause non-trivial initialization work to 3031 // occur. If we're inside a lambda and one of the variables is from the scope 3032 // outside the lambda, that function may have returned already. Reading its 3033 // locals is a bad idea. Also, these reads may introduce races there didn't 3034 // exist in the source-level program. 3035} 3036 3037 3038Value *ScalarExprEmitter:: 3039VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) { 3040 TestAndClearIgnoreResultAssign(); 3041 3042 // Bind the common expression if necessary. 3043 CodeGenFunction::OpaqueValueMapping binding(CGF, E); 3044 3045 Expr *condExpr = E->getCond(); 3046 Expr *lhsExpr = E->getTrueExpr(); 3047 Expr *rhsExpr = E->getFalseExpr(); 3048 3049 // If the condition constant folds and can be elided, try to avoid emitting 3050 // the condition and the dead arm. 3051 bool CondExprBool; 3052 if (CGF.ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) { 3053 Expr *live = lhsExpr, *dead = rhsExpr; 3054 if (!CondExprBool) std::swap(live, dead); 3055 3056 // If the dead side doesn't have labels we need, just emit the Live part. 3057 if (!CGF.ContainsLabel(dead)) { 3058 Value *Result = Visit(live); 3059 3060 // If the live part is a throw expression, it acts like it has a void 3061 // type, so evaluating it returns a null Value*. However, a conditional 3062 // with non-void type must return a non-null Value*. 3063 if (!Result && !E->getType()->isVoidType()) 3064 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType())); 3065 3066 return Result; 3067 } 3068 } 3069 3070 // OpenCL: If the condition is a vector, we can treat this condition like 3071 // the select function. 3072 if (CGF.getLangOpts().OpenCL 3073 && condExpr->getType()->isVectorType()) { 3074 llvm::Value *CondV = CGF.EmitScalarExpr(condExpr); 3075 llvm::Value *LHS = Visit(lhsExpr); 3076 llvm::Value *RHS = Visit(rhsExpr); 3077 3078 llvm::Type *condType = ConvertType(condExpr->getType()); 3079 llvm::VectorType *vecTy = cast<llvm::VectorType>(condType); 3080 3081 unsigned numElem = vecTy->getNumElements(); 3082 llvm::Type *elemType = vecTy->getElementType(); 3083 3084 llvm::Value *zeroVec = llvm::Constant::getNullValue(vecTy); 3085 llvm::Value *TestMSB = Builder.CreateICmpSLT(CondV, zeroVec); 3086 llvm::Value *tmp = Builder.CreateSExt(TestMSB, 3087 llvm::VectorType::get(elemType, 3088 numElem), 3089 "sext"); 3090 llvm::Value *tmp2 = Builder.CreateNot(tmp); 3091 3092 // Cast float to int to perform ANDs if necessary. 3093 llvm::Value *RHSTmp = RHS; 3094 llvm::Value *LHSTmp = LHS; 3095 bool wasCast = false; 3096 llvm::VectorType *rhsVTy = cast<llvm::VectorType>(RHS->getType()); 3097 if (rhsVTy->getElementType()->isFloatingPointTy()) { 3098 RHSTmp = Builder.CreateBitCast(RHS, tmp2->getType()); 3099 LHSTmp = Builder.CreateBitCast(LHS, tmp->getType()); 3100 wasCast = true; 3101 } 3102 3103 llvm::Value *tmp3 = Builder.CreateAnd(RHSTmp, tmp2); 3104 llvm::Value *tmp4 = Builder.CreateAnd(LHSTmp, tmp); 3105 llvm::Value *tmp5 = Builder.CreateOr(tmp3, tmp4, "cond"); 3106 if (wasCast) 3107 tmp5 = Builder.CreateBitCast(tmp5, RHS->getType()); 3108 3109 return tmp5; 3110 } 3111 3112 // If this is a really simple expression (like x ? 4 : 5), emit this as a 3113 // select instead of as control flow. We can only do this if it is cheap and 3114 // safe to evaluate the LHS and RHS unconditionally. 3115 if (isCheapEnoughToEvaluateUnconditionally(lhsExpr, CGF) && 3116 isCheapEnoughToEvaluateUnconditionally(rhsExpr, CGF)) { 3117 llvm::Value *CondV = CGF.EvaluateExprAsBool(condExpr); 3118 llvm::Value *LHS = Visit(lhsExpr); 3119 llvm::Value *RHS = Visit(rhsExpr); 3120 if (!LHS) { 3121 // If the conditional has void type, make sure we return a null Value*. 3122 assert(!RHS && "LHS and RHS types must match"); 3123 return 0; 3124 } 3125 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 3126 } 3127 3128 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 3129 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 3130 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 3131 3132 CodeGenFunction::ConditionalEvaluation eval(CGF); 3133 CGF.EmitBranchOnBoolExpr(condExpr, LHSBlock, RHSBlock); 3134 3135 CGF.EmitBlock(LHSBlock); 3136 eval.begin(CGF); 3137 Value *LHS = Visit(lhsExpr); 3138 eval.end(CGF); 3139 3140 LHSBlock = Builder.GetInsertBlock(); 3141 Builder.CreateBr(ContBlock); 3142 3143 CGF.EmitBlock(RHSBlock); 3144 eval.begin(CGF); 3145 Value *RHS = Visit(rhsExpr); 3146 eval.end(CGF); 3147 3148 RHSBlock = Builder.GetInsertBlock(); 3149 CGF.EmitBlock(ContBlock); 3150 3151 // If the LHS or RHS is a throw expression, it will be legitimately null. 3152 if (!LHS) 3153 return RHS; 3154 if (!RHS) 3155 return LHS; 3156 3157 // Create a PHI node for the real part. 3158 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), 2, "cond"); 3159 PN->addIncoming(LHS, LHSBlock); 3160 PN->addIncoming(RHS, RHSBlock); 3161 return PN; 3162} 3163 3164Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 3165 return Visit(E->getChosenSubExpr()); 3166} 3167 3168Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 3169 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 3170 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 3171 3172 // If EmitVAArg fails, we fall back to the LLVM instruction. 3173 if (!ArgPtr) 3174 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 3175 3176 // FIXME Volatility. 3177 return Builder.CreateLoad(ArgPtr); 3178} 3179 3180Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *block) { 3181 return CGF.EmitBlockLiteral(block); 3182} 3183 3184Value *ScalarExprEmitter::VisitAsTypeExpr(AsTypeExpr *E) { 3185 Value *Src = CGF.EmitScalarExpr(E->getSrcExpr()); 3186 llvm::Type *DstTy = ConvertType(E->getType()); 3187 3188 // Going from vec4->vec3 or vec3->vec4 is a special case and requires 3189 // a shuffle vector instead of a bitcast. 3190 llvm::Type *SrcTy = Src->getType(); 3191 if (isa<llvm::VectorType>(DstTy) && isa<llvm::VectorType>(SrcTy)) { 3192 unsigned numElementsDst = cast<llvm::VectorType>(DstTy)->getNumElements(); 3193 unsigned numElementsSrc = cast<llvm::VectorType>(SrcTy)->getNumElements(); 3194 if ((numElementsDst == 3 && numElementsSrc == 4) 3195 || (numElementsDst == 4 && numElementsSrc == 3)) { 3196 3197 3198 // In the case of going from int4->float3, a bitcast is needed before 3199 // doing a shuffle. 3200 llvm::Type *srcElemTy = 3201 cast<llvm::VectorType>(SrcTy)->getElementType(); 3202 llvm::Type *dstElemTy = 3203 cast<llvm::VectorType>(DstTy)->getElementType(); 3204 3205 if ((srcElemTy->isIntegerTy() && dstElemTy->isFloatTy()) 3206 || (srcElemTy->isFloatTy() && dstElemTy->isIntegerTy())) { 3207 // Create a float type of the same size as the source or destination. 3208 llvm::VectorType *newSrcTy = llvm::VectorType::get(dstElemTy, 3209 numElementsSrc); 3210 3211 Src = Builder.CreateBitCast(Src, newSrcTy, "astypeCast"); 3212 } 3213 3214 llvm::Value *UnV = llvm::UndefValue::get(Src->getType()); 3215 3216 SmallVector<llvm::Constant*, 3> Args; 3217 Args.push_back(Builder.getInt32(0)); 3218 Args.push_back(Builder.getInt32(1)); 3219 Args.push_back(Builder.getInt32(2)); 3220 3221 if (numElementsDst == 4) 3222 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 3223 3224 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 3225 3226 return Builder.CreateShuffleVector(Src, UnV, Mask, "astype"); 3227 } 3228 } 3229 3230 return Builder.CreateBitCast(Src, DstTy, "astype"); 3231} 3232 3233Value *ScalarExprEmitter::VisitAtomicExpr(AtomicExpr *E) { 3234 return CGF.EmitAtomicExpr(E).getScalarVal(); 3235} 3236 3237//===----------------------------------------------------------------------===// 3238// Entry Point into this File 3239//===----------------------------------------------------------------------===// 3240 3241/// EmitScalarExpr - Emit the computation of the specified expression of scalar 3242/// type, ignoring the result. 3243Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 3244 assert(E && hasScalarEvaluationKind(E->getType()) && 3245 "Invalid scalar expression to emit"); 3246 3247 if (isa<CXXDefaultArgExpr>(E)) 3248 disableDebugInfo(); 3249 Value *V = ScalarExprEmitter(*this, IgnoreResultAssign) 3250 .Visit(const_cast<Expr*>(E)); 3251 if (isa<CXXDefaultArgExpr>(E)) 3252 enableDebugInfo(); 3253 return V; 3254} 3255 3256/// EmitScalarConversion - Emit a conversion from the specified type to the 3257/// specified destination type, both of which are LLVM scalar types. 3258Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 3259 QualType DstTy) { 3260 assert(hasScalarEvaluationKind(SrcTy) && hasScalarEvaluationKind(DstTy) && 3261 "Invalid scalar expression to emit"); 3262 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 3263} 3264 3265/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 3266/// type to the specified destination type, where the destination type is an 3267/// LLVM scalar type. 3268Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 3269 QualType SrcTy, 3270 QualType DstTy) { 3271 assert(SrcTy->isAnyComplexType() && hasScalarEvaluationKind(DstTy) && 3272 "Invalid complex -> scalar conversion"); 3273 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 3274 DstTy); 3275} 3276 3277 3278llvm::Value *CodeGenFunction:: 3279EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 3280 bool isInc, bool isPre) { 3281 return ScalarExprEmitter(*this).EmitScalarPrePostIncDec(E, LV, isInc, isPre); 3282} 3283 3284LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) { 3285 llvm::Value *V; 3286 // object->isa or (*object).isa 3287 // Generate code as for: *(Class*)object 3288 // build Class* type 3289 llvm::Type *ClassPtrTy = ConvertType(E->getType()); 3290 3291 Expr *BaseExpr = E->getBase(); 3292 if (BaseExpr->isRValue()) { 3293 V = CreateMemTemp(E->getType(), "resval"); 3294 llvm::Value *Src = EmitScalarExpr(BaseExpr); 3295 Builder.CreateStore(Src, V); 3296 V = ScalarExprEmitter(*this).EmitLoadOfLValue( 3297 MakeNaturalAlignAddrLValue(V, E->getType()), E->getExprLoc()); 3298 } else { 3299 if (E->isArrow()) 3300 V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr); 3301 else 3302 V = EmitLValue(BaseExpr).getAddress(); 3303 } 3304 3305 // build Class* type 3306 ClassPtrTy = ClassPtrTy->getPointerTo(); 3307 V = Builder.CreateBitCast(V, ClassPtrTy); 3308 return MakeNaturalAlignAddrLValue(V, E->getType()); 3309} 3310 3311 3312LValue CodeGenFunction::EmitCompoundAssignmentLValue( 3313 const CompoundAssignOperator *E) { 3314 ScalarExprEmitter Scalar(*this); 3315 Value *Result = 0; 3316 switch (E->getOpcode()) { 3317#define COMPOUND_OP(Op) \ 3318 case BO_##Op##Assign: \ 3319 return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \ 3320 Result) 3321 COMPOUND_OP(Mul); 3322 COMPOUND_OP(Div); 3323 COMPOUND_OP(Rem); 3324 COMPOUND_OP(Add); 3325 COMPOUND_OP(Sub); 3326 COMPOUND_OP(Shl); 3327 COMPOUND_OP(Shr); 3328 COMPOUND_OP(And); 3329 COMPOUND_OP(Xor); 3330 COMPOUND_OP(Or); 3331#undef COMPOUND_OP 3332 3333 case BO_PtrMemD: 3334 case BO_PtrMemI: 3335 case BO_Mul: 3336 case BO_Div: 3337 case BO_Rem: 3338 case BO_Add: 3339 case BO_Sub: 3340 case BO_Shl: 3341 case BO_Shr: 3342 case BO_LT: 3343 case BO_GT: 3344 case BO_LE: 3345 case BO_GE: 3346 case BO_EQ: 3347 case BO_NE: 3348 case BO_And: 3349 case BO_Xor: 3350 case BO_Or: 3351 case BO_LAnd: 3352 case BO_LOr: 3353 case BO_Assign: 3354 case BO_Comma: 3355 llvm_unreachable("Not valid compound assignment operators"); 3356 } 3357 3358 llvm_unreachable("Unhandled compound assignment operator"); 3359} 3360