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 "clang/Frontend/CodeGenOptions.h" 15 #include "CodeGenFunction.h" 16 #include "CGCXXABI.h" 17 #include "CGObjCRuntime.h" 18 #include "CodeGenModule.h" 19 #include "CGDebugInfo.h" 20 #include "clang/AST/ASTContext.h" 21 #include "clang/AST/DeclObjC.h" 22 #include "clang/AST/RecordLayout.h" 23 #include "clang/AST/StmtVisitor.h" 24 #include "clang/Basic/TargetInfo.h" 25 #include "llvm/Constants.h" 26 #include "llvm/Function.h" 27 #include "llvm/GlobalVariable.h" 28 #include "llvm/Intrinsics.h" 29 #include "llvm/Module.h" 30 #include "llvm/Support/CFG.h" 31 #include "llvm/Target/TargetData.h" 32 #include <cstdarg> 33 34 using namespace clang; 35 using namespace CodeGen; 36 using llvm::Value; 37 38 //===----------------------------------------------------------------------===// 39 // Scalar Expression Emitter 40 //===----------------------------------------------------------------------===// 41 42 namespace { 43 struct BinOpInfo { 44 Value *LHS; 45 Value *RHS; 46 QualType Ty; // Computation Type. 47 BinaryOperator::Opcode Opcode; // Opcode of BinOp to perform 48 const Expr *E; // Entire expr, for error unsupported. May not be binop. 49 }; 50 51 static bool MustVisitNullValue(const Expr *E) { 52 // If a null pointer expression's type is the C++0x nullptr_t, then 53 // it's not necessarily a simple constant and it must be evaluated 54 // for its potential side effects. 55 return E->getType()->isNullPtrType(); 56 } 57 58 class ScalarExprEmitter 59 : public StmtVisitor<ScalarExprEmitter, Value*> { 60 CodeGenFunction &CGF; 61 CGBuilderTy &Builder; 62 bool IgnoreResultAssign; 63 llvm::LLVMContext &VMContext; 64 public: 65 66 ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false) 67 : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira), 68 VMContext(cgf.getLLVMContext()) { 69 } 70 71 //===--------------------------------------------------------------------===// 72 // Utilities 73 //===--------------------------------------------------------------------===// 74 75 bool TestAndClearIgnoreResultAssign() { 76 bool I = IgnoreResultAssign; 77 IgnoreResultAssign = false; 78 return I; 79 } 80 81 llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); } 82 LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); } 83 LValue EmitCheckedLValue(const Expr *E) { return CGF.EmitCheckedLValue(E); } 84 85 Value *EmitLoadOfLValue(LValue LV) { 86 return CGF.EmitLoadOfLValue(LV).getScalarVal(); 87 } 88 89 /// EmitLoadOfLValue - Given an expression with complex type that represents a 90 /// value l-value, this method emits the address of the l-value, then loads 91 /// and returns the result. 92 Value *EmitLoadOfLValue(const Expr *E) { 93 return EmitLoadOfLValue(EmitCheckedLValue(E)); 94 } 95 96 /// EmitConversionToBool - Convert the specified expression value to a 97 /// boolean (i1) truth value. This is equivalent to "Val != 0". 98 Value *EmitConversionToBool(Value *Src, QualType DstTy); 99 100 /// EmitScalarConversion - Emit a conversion from the specified type to the 101 /// specified destination type, both of which are LLVM scalar types. 102 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); 103 104 /// EmitComplexToScalarConversion - Emit a conversion from the specified 105 /// complex type to the specified destination type, where the destination type 106 /// is an LLVM scalar type. 107 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 108 QualType SrcTy, QualType DstTy); 109 110 /// EmitNullValue - Emit a value that corresponds to null for the given type. 111 Value *EmitNullValue(QualType Ty); 112 113 /// EmitFloatToBoolConversion - Perform an FP to boolean conversion. 114 Value *EmitFloatToBoolConversion(Value *V) { 115 // Compare against 0.0 for fp scalars. 116 llvm::Value *Zero = llvm::Constant::getNullValue(V->getType()); 117 return Builder.CreateFCmpUNE(V, Zero, "tobool"); 118 } 119 120 /// EmitPointerToBoolConversion - Perform a pointer to boolean conversion. 121 Value *EmitPointerToBoolConversion(Value *V) { 122 Value *Zero = llvm::ConstantPointerNull::get( 123 cast<llvm::PointerType>(V->getType())); 124 return Builder.CreateICmpNE(V, Zero, "tobool"); 125 } 126 127 Value *EmitIntToBoolConversion(Value *V) { 128 // Because of the type rules of C, we often end up computing a 129 // logical value, then zero extending it to int, then wanting it 130 // as a logical value again. Optimize this common case. 131 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(V)) { 132 if (ZI->getOperand(0)->getType() == Builder.getInt1Ty()) { 133 Value *Result = ZI->getOperand(0); 134 // If there aren't any more uses, zap the instruction to save space. 135 // Note that there can be more uses, for example if this 136 // is the result of an assignment. 137 if (ZI->use_empty()) 138 ZI->eraseFromParent(); 139 return Result; 140 } 141 } 142 143 return Builder.CreateIsNotNull(V, "tobool"); 144 } 145 146 //===--------------------------------------------------------------------===// 147 // Visitor Methods 148 //===--------------------------------------------------------------------===// 149 150 Value *Visit(Expr *E) { 151 return StmtVisitor<ScalarExprEmitter, Value*>::Visit(E); 152 } 153 154 Value *VisitStmt(Stmt *S) { 155 S->dump(CGF.getContext().getSourceManager()); 156 llvm_unreachable("Stmt can't have complex result type!"); 157 } 158 Value *VisitExpr(Expr *S); 159 160 Value *VisitParenExpr(ParenExpr *PE) { 161 return Visit(PE->getSubExpr()); 162 } 163 Value *VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) { 164 return Visit(E->getReplacement()); 165 } 166 Value *VisitGenericSelectionExpr(GenericSelectionExpr *GE) { 167 return Visit(GE->getResultExpr()); 168 } 169 170 // Leaves. 171 Value *VisitIntegerLiteral(const IntegerLiteral *E) { 172 return Builder.getInt(E->getValue()); 173 } 174 Value *VisitFloatingLiteral(const FloatingLiteral *E) { 175 return llvm::ConstantFP::get(VMContext, E->getValue()); 176 } 177 Value *VisitCharacterLiteral(const CharacterLiteral *E) { 178 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 179 } 180 Value *VisitObjCBoolLiteralExpr(const ObjCBoolLiteralExpr *E) { 181 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 182 } 183 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 184 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 185 } 186 Value *VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) { 187 return EmitNullValue(E->getType()); 188 } 189 Value *VisitGNUNullExpr(const GNUNullExpr *E) { 190 return EmitNullValue(E->getType()); 191 } 192 Value *VisitOffsetOfExpr(OffsetOfExpr *E); 193 Value *VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E); 194 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 195 llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel()); 196 return Builder.CreateBitCast(V, ConvertType(E->getType())); 197 } 198 199 Value *VisitSizeOfPackExpr(SizeOfPackExpr *E) { 200 return llvm::ConstantInt::get(ConvertType(E->getType()),E->getPackLength()); 201 } 202 203 Value *VisitPseudoObjectExpr(PseudoObjectExpr *E) { 204 return CGF.EmitPseudoObjectRValue(E).getScalarVal(); 205 } 206 207 Value *VisitOpaqueValueExpr(OpaqueValueExpr *E) { 208 if (E->isGLValue()) 209 return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E)); 210 211 // Otherwise, assume the mapping is the scalar directly. 212 return CGF.getOpaqueRValueMapping(E).getScalarVal(); 213 } 214 215 // l-values. 216 Value *VisitDeclRefExpr(DeclRefExpr *E) { 217 if (CodeGenFunction::ConstantEmission result = CGF.tryEmitAsConstant(E)) { 218 if (result.isReference()) 219 return EmitLoadOfLValue(result.getReferenceLValue(CGF, E)); 220 return result.getValue(); 221 } 222 return EmitLoadOfLValue(E); 223 } 224 225 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 226 return CGF.EmitObjCSelectorExpr(E); 227 } 228 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 229 return CGF.EmitObjCProtocolExpr(E); 230 } 231 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 232 return EmitLoadOfLValue(E); 233 } 234 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 235 if (E->getMethodDecl() && 236 E->getMethodDecl()->getResultType()->isReferenceType()) 237 return EmitLoadOfLValue(E); 238 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 239 } 240 241 Value *VisitObjCIsaExpr(ObjCIsaExpr *E) { 242 LValue LV = CGF.EmitObjCIsaExpr(E); 243 Value *V = CGF.EmitLoadOfLValue(LV).getScalarVal(); 244 return V; 245 } 246 247 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 248 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 249 Value *VisitMemberExpr(MemberExpr *E); 250 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 251 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 252 return EmitLoadOfLValue(E); 253 } 254 255 Value *VisitInitListExpr(InitListExpr *E); 256 257 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { 258 return CGF.CGM.EmitNullConstant(E->getType()); 259 } 260 Value *VisitExplicitCastExpr(ExplicitCastExpr *E) { 261 if (E->getType()->isVariablyModifiedType()) 262 CGF.EmitVariablyModifiedType(E->getType()); 263 return VisitCastExpr(E); 264 } 265 Value *VisitCastExpr(CastExpr *E); 266 267 Value *VisitCallExpr(const CallExpr *E) { 268 if (E->getCallReturnType()->isReferenceType()) 269 return EmitLoadOfLValue(E); 270 271 return CGF.EmitCallExpr(E).getScalarVal(); 272 } 273 274 Value *VisitStmtExpr(const StmtExpr *E); 275 276 // Unary Operators. 277 Value *VisitUnaryPostDec(const UnaryOperator *E) { 278 LValue LV = EmitLValue(E->getSubExpr()); 279 return EmitScalarPrePostIncDec(E, LV, false, false); 280 } 281 Value *VisitUnaryPostInc(const UnaryOperator *E) { 282 LValue LV = EmitLValue(E->getSubExpr()); 283 return EmitScalarPrePostIncDec(E, LV, true, false); 284 } 285 Value *VisitUnaryPreDec(const UnaryOperator *E) { 286 LValue LV = EmitLValue(E->getSubExpr()); 287 return EmitScalarPrePostIncDec(E, LV, false, true); 288 } 289 Value *VisitUnaryPreInc(const UnaryOperator *E) { 290 LValue LV = EmitLValue(E->getSubExpr()); 291 return EmitScalarPrePostIncDec(E, LV, true, true); 292 } 293 294 llvm::Value *EmitAddConsiderOverflowBehavior(const UnaryOperator *E, 295 llvm::Value *InVal, 296 llvm::Value *NextVal, 297 bool IsInc); 298 299 llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 300 bool isInc, bool isPre); 301 302 303 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 304 if (isa<MemberPointerType>(E->getType())) // never sugared 305 return CGF.CGM.getMemberPointerConstant(E); 306 307 return EmitLValue(E->getSubExpr()).getAddress(); 308 } 309 Value *VisitUnaryDeref(const UnaryOperator *E) { 310 if (E->getType()->isVoidType()) 311 return Visit(E->getSubExpr()); // the actual value should be unused 312 return EmitLoadOfLValue(E); 313 } 314 Value *VisitUnaryPlus(const UnaryOperator *E) { 315 // This differs from gcc, though, most likely due to a bug in gcc. 316 TestAndClearIgnoreResultAssign(); 317 return Visit(E->getSubExpr()); 318 } 319 Value *VisitUnaryMinus (const UnaryOperator *E); 320 Value *VisitUnaryNot (const UnaryOperator *E); 321 Value *VisitUnaryLNot (const UnaryOperator *E); 322 Value *VisitUnaryReal (const UnaryOperator *E); 323 Value *VisitUnaryImag (const UnaryOperator *E); 324 Value *VisitUnaryExtension(const UnaryOperator *E) { 325 return Visit(E->getSubExpr()); 326 } 327 328 // C++ 329 Value *VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E) { 330 return EmitLoadOfLValue(E); 331 } 332 333 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 334 return Visit(DAE->getExpr()); 335 } 336 Value *VisitCXXThisExpr(CXXThisExpr *TE) { 337 return CGF.LoadCXXThis(); 338 } 339 340 Value *VisitExprWithCleanups(ExprWithCleanups *E) { 341 CGF.enterFullExpression(E); 342 CodeGenFunction::RunCleanupsScope Scope(CGF); 343 return Visit(E->getSubExpr()); 344 } 345 Value *VisitCXXNewExpr(const CXXNewExpr *E) { 346 return CGF.EmitCXXNewExpr(E); 347 } 348 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { 349 CGF.EmitCXXDeleteExpr(E); 350 return 0; 351 } 352 Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) { 353 return Builder.getInt1(E->getValue()); 354 } 355 356 Value *VisitBinaryTypeTraitExpr(const BinaryTypeTraitExpr *E) { 357 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 358 } 359 360 Value *VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) { 361 return llvm::ConstantInt::get(Builder.getInt32Ty(), E->getValue()); 362 } 363 364 Value *VisitExpressionTraitExpr(const ExpressionTraitExpr *E) { 365 return llvm::ConstantInt::get(Builder.getInt1Ty(), E->getValue()); 366 } 367 368 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { 369 // C++ [expr.pseudo]p1: 370 // The result shall only be used as the operand for the function call 371 // operator (), and the result of such a call has type void. The only 372 // effect is the evaluation of the postfix-expression before the dot or 373 // arrow. 374 CGF.EmitScalarExpr(E->getBase()); 375 return 0; 376 } 377 378 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { 379 return EmitNullValue(E->getType()); 380 } 381 382 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { 383 CGF.EmitCXXThrowExpr(E); 384 return 0; 385 } 386 387 Value *VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) { 388 return Builder.getInt1(E->getValue()); 389 } 390 391 // Binary Operators. 392 Value *EmitMul(const BinOpInfo &Ops) { 393 if (Ops.Ty->isSignedIntegerOrEnumerationType()) { 394 switch (CGF.getContext().getLangOpts().getSignedOverflowBehavior()) { 395 case LangOptions::SOB_Undefined: 396 return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul"); 397 case LangOptions::SOB_Defined: 398 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 399 case LangOptions::SOB_Trapping: 400 return EmitOverflowCheckedBinOp(Ops); 401 } 402 } 403 404 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 405 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 406 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 407 } 408 bool isTrapvOverflowBehavior() { 409 return CGF.getContext().getLangOpts().getSignedOverflowBehavior() 410 == LangOptions::SOB_Trapping; 411 } 412 /// Create a binary op that checks for overflow. 413 /// Currently only supports +, - and *. 414 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 415 // Emit the overflow BB when -ftrapv option is activated. 416 void EmitOverflowBB(llvm::BasicBlock *overflowBB) { 417 Builder.SetInsertPoint(overflowBB); 418 llvm::Function *Trap = CGF.CGM.getIntrinsic(llvm::Intrinsic::trap); 419 Builder.CreateCall(Trap); 420 Builder.CreateUnreachable(); 421 } 422 // Check for undefined division and modulus behaviors. 423 void EmitUndefinedBehaviorIntegerDivAndRemCheck(const BinOpInfo &Ops, 424 llvm::Value *Zero,bool isDiv); 425 Value *EmitDiv(const BinOpInfo &Ops); 426 Value *EmitRem(const BinOpInfo &Ops); 427 Value *EmitAdd(const BinOpInfo &Ops); 428 Value *EmitSub(const BinOpInfo &Ops); 429 Value *EmitShl(const BinOpInfo &Ops); 430 Value *EmitShr(const BinOpInfo &Ops); 431 Value *EmitAnd(const BinOpInfo &Ops) { 432 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 433 } 434 Value *EmitXor(const BinOpInfo &Ops) { 435 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 436 } 437 Value *EmitOr (const BinOpInfo &Ops) { 438 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 439 } 440 441 BinOpInfo EmitBinOps(const BinaryOperator *E); 442 LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E, 443 Value *(ScalarExprEmitter::*F)(const BinOpInfo &), 444 Value *&Result); 445 446 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 447 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 448 449 // Binary operators and binary compound assignment operators. 450 #define HANDLEBINOP(OP) \ 451 Value *VisitBin ## OP(const BinaryOperator *E) { \ 452 return Emit ## OP(EmitBinOps(E)); \ 453 } \ 454 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 455 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 456 } 457 HANDLEBINOP(Mul) 458 HANDLEBINOP(Div) 459 HANDLEBINOP(Rem) 460 HANDLEBINOP(Add) 461 HANDLEBINOP(Sub) 462 HANDLEBINOP(Shl) 463 HANDLEBINOP(Shr) 464 HANDLEBINOP(And) 465 HANDLEBINOP(Xor) 466 HANDLEBINOP(Or) 467 #undef HANDLEBINOP 468 469 // Comparisons. 470 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 471 unsigned SICmpOpc, unsigned FCmpOpc); 472 #define VISITCOMP(CODE, UI, SI, FP) \ 473 Value *VisitBin##CODE(const BinaryOperator *E) { \ 474 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 475 llvm::FCmpInst::FP); } 476 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT) 477 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT) 478 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE) 479 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE) 480 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ) 481 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE) 482 #undef VISITCOMP 483 484 Value *VisitBinAssign (const BinaryOperator *E); 485 486 Value *VisitBinLAnd (const BinaryOperator *E); 487 Value *VisitBinLOr (const BinaryOperator *E); 488 Value *VisitBinComma (const BinaryOperator *E); 489 490 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } 491 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); } 492 493 // Other Operators. 494 Value *VisitBlockExpr(const BlockExpr *BE); 495 Value *VisitAbstractConditionalOperator(const AbstractConditionalOperator *); 496 Value *VisitChooseExpr(ChooseExpr *CE); 497 Value *VisitVAArgExpr(VAArgExpr *VE); 498 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 499 return CGF.EmitObjCStringLiteral(E); 500 } 501 Value *VisitObjCBoxedExpr(ObjCBoxedExpr *E) { 502 return CGF.EmitObjCBoxedExpr(E); 503 } 504 Value *VisitObjCArrayLiteral(ObjCArrayLiteral *E) { 505 return CGF.EmitObjCArrayLiteral(E); 506 } 507 Value *VisitObjCDictionaryLiteral(ObjCDictionaryLiteral *E) { 508 return CGF.EmitObjCDictionaryLiteral(E); 509 } 510 Value *VisitAsTypeExpr(AsTypeExpr *CE); 511 Value *VisitAtomicExpr(AtomicExpr *AE); 512 }; 513 } // end anonymous namespace. 514 515 //===----------------------------------------------------------------------===// 516 // Utilities 517 //===----------------------------------------------------------------------===// 518 519 /// EmitConversionToBool - Convert the specified expression value to a 520 /// boolean (i1) truth value. This is equivalent to "Val != 0". 521 Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 522 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs"); 523 524 if (SrcType->isRealFloatingType()) 525 return EmitFloatToBoolConversion(Src); 526 527 if (const MemberPointerType *MPT = dyn_cast<MemberPointerType>(SrcType)) 528 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, Src, MPT); 529 530 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 531 "Unknown scalar type to convert"); 532 533 if (isa<llvm::IntegerType>(Src->getType())) 534 return EmitIntToBoolConversion(Src); 535 536 assert(isa<llvm::PointerType>(Src->getType())); 537 return EmitPointerToBoolConversion(Src); 538 } 539 540 /// EmitScalarConversion - Emit a conversion from the specified type to the 541 /// specified destination type, both of which are LLVM scalar types. 542 Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 543 QualType DstType) { 544 SrcType = CGF.getContext().getCanonicalType(SrcType); 545 DstType = CGF.getContext().getCanonicalType(DstType); 546 if (SrcType == DstType) return Src; 547 548 if (DstType->isVoidType()) return 0; 549 550 llvm::Type *SrcTy = Src->getType(); 551 552 // Floating casts might be a bit special: if we're doing casts to / from half 553 // FP, we should go via special intrinsics. 554 if (SrcType->isHalfType()) { 555 Src = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16), Src); 556 SrcType = CGF.getContext().FloatTy; 557 SrcTy = CGF.FloatTy; 558 } 559 560 // Handle conversions to bool first, they are special: comparisons against 0. 561 if (DstType->isBooleanType()) 562 return EmitConversionToBool(Src, SrcType); 563 564 llvm::Type *DstTy = ConvertType(DstType); 565 566 // Ignore conversions like int -> uint. 567 if (SrcTy == DstTy) 568 return Src; 569 570 // Handle pointer conversions next: pointers can only be converted to/from 571 // other pointers and integers. Check for pointer types in terms of LLVM, as 572 // some native types (like Obj-C id) may map to a pointer type. 573 if (isa<llvm::PointerType>(DstTy)) { 574 // The source value may be an integer, or a pointer. 575 if (isa<llvm::PointerType>(SrcTy)) 576 return Builder.CreateBitCast(Src, DstTy, "conv"); 577 578 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 579 // First, convert to the correct width so that we control the kind of 580 // extension. 581 llvm::Type *MiddleTy = CGF.IntPtrTy; 582 bool InputSigned = SrcType->isSignedIntegerOrEnumerationType(); 583 llvm::Value* IntResult = 584 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 585 // Then, cast to pointer. 586 return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); 587 } 588 589 if (isa<llvm::PointerType>(SrcTy)) { 590 // Must be an ptr to int cast. 591 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 592 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 593 } 594 595 // A scalar can be splatted to an extended vector of the same element type 596 if (DstType->isExtVectorType() && !SrcType->isVectorType()) { 597 // Cast the scalar to element type 598 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType(); 599 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 600 601 // Insert the element in element zero of an undef vector 602 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 603 llvm::Value *Idx = Builder.getInt32(0); 604 UnV = Builder.CreateInsertElement(UnV, Elt, Idx); 605 606 // Splat the element across to all elements 607 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 608 llvm::Constant *Mask = llvm::ConstantVector::getSplat(NumElements, 609 Builder.getInt32(0)); 610 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 611 return Yay; 612 } 613 614 // Allow bitcast from vector to integer/fp of the same size. 615 if (isa<llvm::VectorType>(SrcTy) || 616 isa<llvm::VectorType>(DstTy)) 617 return Builder.CreateBitCast(Src, DstTy, "conv"); 618 619 // Finally, we have the arithmetic types: real int/float. 620 Value *Res = NULL; 621 llvm::Type *ResTy = DstTy; 622 623 // Cast to half via float 624 if (DstType->isHalfType()) 625 DstTy = CGF.FloatTy; 626 627 if (isa<llvm::IntegerType>(SrcTy)) { 628 bool InputSigned = SrcType->isSignedIntegerOrEnumerationType(); 629 if (isa<llvm::IntegerType>(DstTy)) 630 Res = Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 631 else if (InputSigned) 632 Res = Builder.CreateSIToFP(Src, DstTy, "conv"); 633 else 634 Res = Builder.CreateUIToFP(Src, DstTy, "conv"); 635 } else if (isa<llvm::IntegerType>(DstTy)) { 636 assert(SrcTy->isFloatingPointTy() && "Unknown real conversion"); 637 if (DstType->isSignedIntegerOrEnumerationType()) 638 Res = Builder.CreateFPToSI(Src, DstTy, "conv"); 639 else 640 Res = Builder.CreateFPToUI(Src, DstTy, "conv"); 641 } else { 642 assert(SrcTy->isFloatingPointTy() && DstTy->isFloatingPointTy() && 643 "Unknown real conversion"); 644 if (DstTy->getTypeID() < SrcTy->getTypeID()) 645 Res = Builder.CreateFPTrunc(Src, DstTy, "conv"); 646 else 647 Res = Builder.CreateFPExt(Src, DstTy, "conv"); 648 } 649 650 if (DstTy != ResTy) { 651 assert(ResTy->isIntegerTy(16) && "Only half FP requires extra conversion"); 652 Res = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16), Res); 653 } 654 655 return Res; 656 } 657 658 /// EmitComplexToScalarConversion - Emit a conversion from the specified complex 659 /// type to the specified destination type, where the destination type is an 660 /// LLVM scalar type. 661 Value *ScalarExprEmitter:: 662 EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 663 QualType SrcTy, QualType DstTy) { 664 // Get the source element type. 665 SrcTy = SrcTy->getAs<ComplexType>()->getElementType(); 666 667 // Handle conversions to bool first, they are special: comparisons against 0. 668 if (DstTy->isBooleanType()) { 669 // Complex != 0 -> (Real != 0) | (Imag != 0) 670 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 671 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 672 return Builder.CreateOr(Src.first, Src.second, "tobool"); 673 } 674 675 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 676 // the imaginary part of the complex value is discarded and the value of the 677 // real part is converted according to the conversion rules for the 678 // corresponding real type. 679 return EmitScalarConversion(Src.first, SrcTy, DstTy); 680 } 681 682 Value *ScalarExprEmitter::EmitNullValue(QualType Ty) { 683 if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>()) 684 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 685 686 return llvm::Constant::getNullValue(ConvertType(Ty)); 687 } 688 689 //===----------------------------------------------------------------------===// 690 // Visitor Methods 691 //===----------------------------------------------------------------------===// 692 693 Value *ScalarExprEmitter::VisitExpr(Expr *E) { 694 CGF.ErrorUnsupported(E, "scalar expression"); 695 if (E->getType()->isVoidType()) 696 return 0; 697 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 698 } 699 700 Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 701 // Vector Mask Case 702 if (E->getNumSubExprs() == 2 || 703 (E->getNumSubExprs() == 3 && E->getExpr(2)->getType()->isVectorType())) { 704 Value *LHS = CGF.EmitScalarExpr(E->getExpr(0)); 705 Value *RHS = CGF.EmitScalarExpr(E->getExpr(1)); 706 Value *Mask; 707 708 llvm::VectorType *LTy = cast<llvm::VectorType>(LHS->getType()); 709 unsigned LHSElts = LTy->getNumElements(); 710 711 if (E->getNumSubExprs() == 3) { 712 Mask = CGF.EmitScalarExpr(E->getExpr(2)); 713 714 // Shuffle LHS & RHS into one input vector. 715 SmallVector<llvm::Constant*, 32> concat; 716 for (unsigned i = 0; i != LHSElts; ++i) { 717 concat.push_back(Builder.getInt32(2*i)); 718 concat.push_back(Builder.getInt32(2*i+1)); 719 } 720 721 Value* CV = llvm::ConstantVector::get(concat); 722 LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat"); 723 LHSElts *= 2; 724 } else { 725 Mask = RHS; 726 } 727 728 llvm::VectorType *MTy = cast<llvm::VectorType>(Mask->getType()); 729 llvm::Constant* EltMask; 730 731 // Treat vec3 like vec4. 732 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) 733 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 734 (1 << llvm::Log2_32(LHSElts+2))-1); 735 else if ((LHSElts == 3) && (E->getNumSubExprs() == 2)) 736 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 737 (1 << llvm::Log2_32(LHSElts+1))-1); 738 else 739 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 740 (1 << llvm::Log2_32(LHSElts))-1); 741 742 // Mask off the high bits of each shuffle index. 743 Value *MaskBits = llvm::ConstantVector::getSplat(MTy->getNumElements(), 744 EltMask); 745 Mask = Builder.CreateAnd(Mask, MaskBits, "mask"); 746 747 // newv = undef 748 // mask = mask & maskbits 749 // for each elt 750 // n = extract mask i 751 // x = extract val n 752 // newv = insert newv, x, i 753 llvm::VectorType *RTy = llvm::VectorType::get(LTy->getElementType(), 754 MTy->getNumElements()); 755 Value* NewV = llvm::UndefValue::get(RTy); 756 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) { 757 Value *IIndx = Builder.getInt32(i); 758 Value *Indx = Builder.CreateExtractElement(Mask, IIndx, "shuf_idx"); 759 Indx = Builder.CreateZExt(Indx, CGF.Int32Ty, "idx_zext"); 760 761 // Handle vec3 special since the index will be off by one for the RHS. 762 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) { 763 Value *cmpIndx, *newIndx; 764 cmpIndx = Builder.CreateICmpUGT(Indx, Builder.getInt32(3), 765 "cmp_shuf_idx"); 766 newIndx = Builder.CreateSub(Indx, Builder.getInt32(1), "shuf_idx_adj"); 767 Indx = Builder.CreateSelect(cmpIndx, newIndx, Indx, "sel_shuf_idx"); 768 } 769 Value *VExt = Builder.CreateExtractElement(LHS, Indx, "shuf_elt"); 770 NewV = Builder.CreateInsertElement(NewV, VExt, IIndx, "shuf_ins"); 771 } 772 return NewV; 773 } 774 775 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 776 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 777 778 // Handle vec3 special since the index will be off by one for the RHS. 779 llvm::VectorType *VTy = cast<llvm::VectorType>(V1->getType()); 780 SmallVector<llvm::Constant*, 32> indices; 781 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 782 unsigned Idx = E->getShuffleMaskIdx(CGF.getContext(), i-2); 783 if (VTy->getNumElements() == 3 && Idx > 3) 784 Idx -= 1; 785 indices.push_back(Builder.getInt32(Idx)); 786 } 787 788 Value *SV = llvm::ConstantVector::get(indices); 789 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 790 } 791 Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { 792 llvm::APSInt Value; 793 if (E->EvaluateAsInt(Value, CGF.getContext(), Expr::SE_AllowSideEffects)) { 794 if (E->isArrow()) 795 CGF.EmitScalarExpr(E->getBase()); 796 else 797 EmitLValue(E->getBase()); 798 return Builder.getInt(Value); 799 } 800 801 // Emit debug info for aggregate now, if it was delayed to reduce 802 // debug info size. 803 CGDebugInfo *DI = CGF.getDebugInfo(); 804 if (DI && CGF.CGM.getCodeGenOpts().LimitDebugInfo) { 805 QualType PQTy = E->getBase()->IgnoreParenImpCasts()->getType(); 806 if (const PointerType * PTy = dyn_cast<PointerType>(PQTy)) 807 if (FieldDecl *M = dyn_cast<FieldDecl>(E->getMemberDecl())) 808 DI->getOrCreateRecordType(PTy->getPointeeType(), 809 M->getParent()->getLocation()); 810 } 811 return EmitLoadOfLValue(E); 812 } 813 814 Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 815 TestAndClearIgnoreResultAssign(); 816 817 // Emit subscript expressions in rvalue context's. For most cases, this just 818 // loads the lvalue formed by the subscript expr. However, we have to be 819 // careful, because the base of a vector subscript is occasionally an rvalue, 820 // so we can't get it as an lvalue. 821 if (!E->getBase()->getType()->isVectorType()) 822 return EmitLoadOfLValue(E); 823 824 // Handle the vector case. The base must be a vector, the index must be an 825 // integer value. 826 Value *Base = Visit(E->getBase()); 827 Value *Idx = Visit(E->getIdx()); 828 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerOrEnumerationType(); 829 Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vecidxcast"); 830 return Builder.CreateExtractElement(Base, Idx, "vecext"); 831 } 832 833 static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, 834 unsigned Off, llvm::Type *I32Ty) { 835 int MV = SVI->getMaskValue(Idx); 836 if (MV == -1) 837 return llvm::UndefValue::get(I32Ty); 838 return llvm::ConstantInt::get(I32Ty, Off+MV); 839 } 840 841 Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) { 842 bool Ignore = TestAndClearIgnoreResultAssign(); 843 (void)Ignore; 844 assert (Ignore == false && "init list ignored"); 845 unsigned NumInitElements = E->getNumInits(); 846 847 if (E->hadArrayRangeDesignator()) 848 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 849 850 llvm::VectorType *VType = 851 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 852 853 if (!VType) { 854 if (NumInitElements == 0) { 855 // C++11 value-initialization for the scalar. 856 return EmitNullValue(E->getType()); 857 } 858 // We have a scalar in braces. Just use the first element. 859 return Visit(E->getInit(0)); 860 } 861 862 unsigned ResElts = VType->getNumElements(); 863 864 // Loop over initializers collecting the Value for each, and remembering 865 // whether the source was swizzle (ExtVectorElementExpr). This will allow 866 // us to fold the shuffle for the swizzle into the shuffle for the vector 867 // initializer, since LLVM optimizers generally do not want to touch 868 // shuffles. 869 unsigned CurIdx = 0; 870 bool VIsUndefShuffle = false; 871 llvm::Value *V = llvm::UndefValue::get(VType); 872 for (unsigned i = 0; i != NumInitElements; ++i) { 873 Expr *IE = E->getInit(i); 874 Value *Init = Visit(IE); 875 SmallVector<llvm::Constant*, 16> Args; 876 877 llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType()); 878 879 // Handle scalar elements. If the scalar initializer is actually one 880 // element of a different vector of the same width, use shuffle instead of 881 // extract+insert. 882 if (!VVT) { 883 if (isa<ExtVectorElementExpr>(IE)) { 884 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init); 885 886 if (EI->getVectorOperandType()->getNumElements() == ResElts) { 887 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand()); 888 Value *LHS = 0, *RHS = 0; 889 if (CurIdx == 0) { 890 // insert into undef -> shuffle (src, undef) 891 Args.push_back(C); 892 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 893 894 LHS = EI->getVectorOperand(); 895 RHS = V; 896 VIsUndefShuffle = true; 897 } else if (VIsUndefShuffle) { 898 // insert into undefshuffle && size match -> shuffle (v, src) 899 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V); 900 for (unsigned j = 0; j != CurIdx; ++j) 901 Args.push_back(getMaskElt(SVV, j, 0, CGF.Int32Ty)); 902 Args.push_back(Builder.getInt32(ResElts + C->getZExtValue())); 903 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 904 905 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 906 RHS = EI->getVectorOperand(); 907 VIsUndefShuffle = false; 908 } 909 if (!Args.empty()) { 910 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 911 V = Builder.CreateShuffleVector(LHS, RHS, Mask); 912 ++CurIdx; 913 continue; 914 } 915 } 916 } 917 V = Builder.CreateInsertElement(V, Init, Builder.getInt32(CurIdx), 918 "vecinit"); 919 VIsUndefShuffle = false; 920 ++CurIdx; 921 continue; 922 } 923 924 unsigned InitElts = VVT->getNumElements(); 925 926 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's 927 // input is the same width as the vector being constructed, generate an 928 // optimized shuffle of the swizzle input into the result. 929 unsigned Offset = (CurIdx == 0) ? 0 : ResElts; 930 if (isa<ExtVectorElementExpr>(IE)) { 931 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init); 932 Value *SVOp = SVI->getOperand(0); 933 llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType()); 934 935 if (OpTy->getNumElements() == ResElts) { 936 for (unsigned j = 0; j != CurIdx; ++j) { 937 // If the current vector initializer is a shuffle with undef, merge 938 // this shuffle directly into it. 939 if (VIsUndefShuffle) { 940 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0, 941 CGF.Int32Ty)); 942 } else { 943 Args.push_back(Builder.getInt32(j)); 944 } 945 } 946 for (unsigned j = 0, je = InitElts; j != je; ++j) 947 Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty)); 948 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 949 950 if (VIsUndefShuffle) 951 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 952 953 Init = SVOp; 954 } 955 } 956 957 // Extend init to result vector length, and then shuffle its contribution 958 // to the vector initializer into V. 959 if (Args.empty()) { 960 for (unsigned j = 0; j != InitElts; ++j) 961 Args.push_back(Builder.getInt32(j)); 962 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 963 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 964 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), 965 Mask, "vext"); 966 967 Args.clear(); 968 for (unsigned j = 0; j != CurIdx; ++j) 969 Args.push_back(Builder.getInt32(j)); 970 for (unsigned j = 0; j != InitElts; ++j) 971 Args.push_back(Builder.getInt32(j+Offset)); 972 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 973 } 974 975 // If V is undef, make sure it ends up on the RHS of the shuffle to aid 976 // merging subsequent shuffles into this one. 977 if (CurIdx == 0) 978 std::swap(V, Init); 979 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 980 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); 981 VIsUndefShuffle = isa<llvm::UndefValue>(Init); 982 CurIdx += InitElts; 983 } 984 985 // FIXME: evaluate codegen vs. shuffling against constant null vector. 986 // Emit remaining default initializers. 987 llvm::Type *EltTy = VType->getElementType(); 988 989 // Emit remaining default initializers 990 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { 991 Value *Idx = Builder.getInt32(CurIdx); 992 llvm::Value *Init = llvm::Constant::getNullValue(EltTy); 993 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 994 } 995 return V; 996 } 997 998 static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { 999 const Expr *E = CE->getSubExpr(); 1000 1001 if (CE->getCastKind() == CK_UncheckedDerivedToBase) 1002 return false; 1003 1004 if (isa<CXXThisExpr>(E)) { 1005 // We always assume that 'this' is never null. 1006 return false; 1007 } 1008 1009 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { 1010 // And that glvalue casts are never null. 1011 if (ICE->getValueKind() != VK_RValue) 1012 return false; 1013 } 1014 1015 return true; 1016 } 1017 1018 // VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 1019 // have to handle a more broad range of conversions than explicit casts, as they 1020 // handle things like function to ptr-to-function decay etc. 1021 Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) { 1022 Expr *E = CE->getSubExpr(); 1023 QualType DestTy = CE->getType(); 1024 CastKind Kind = CE->getCastKind(); 1025 1026 if (!DestTy->isVoidType()) 1027 TestAndClearIgnoreResultAssign(); 1028 1029 // Since almost all cast kinds apply to scalars, this switch doesn't have 1030 // a default case, so the compiler will warn on a missing case. The cases 1031 // are in the same order as in the CastKind enum. 1032 switch (Kind) { 1033 case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!"); 1034 1035 case CK_LValueBitCast: 1036 case CK_ObjCObjectLValueCast: { 1037 Value *V = EmitLValue(E).getAddress(); 1038 V = Builder.CreateBitCast(V, 1039 ConvertType(CGF.getContext().getPointerType(DestTy))); 1040 return EmitLoadOfLValue(CGF.MakeNaturalAlignAddrLValue(V, DestTy)); 1041 } 1042 1043 case CK_CPointerToObjCPointerCast: 1044 case CK_BlockPointerToObjCPointerCast: 1045 case CK_AnyPointerToBlockPointerCast: 1046 case CK_BitCast: { 1047 Value *Src = Visit(const_cast<Expr*>(E)); 1048 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 1049 } 1050 case CK_AtomicToNonAtomic: 1051 case CK_NonAtomicToAtomic: 1052 case CK_NoOp: 1053 case CK_UserDefinedConversion: 1054 return Visit(const_cast<Expr*>(E)); 1055 1056 case CK_BaseToDerived: { 1057 const CXXRecordDecl *DerivedClassDecl = 1058 DestTy->getCXXRecordDeclForPointerType(); 1059 1060 return CGF.GetAddressOfDerivedClass(Visit(E), DerivedClassDecl, 1061 CE->path_begin(), CE->path_end(), 1062 ShouldNullCheckClassCastValue(CE)); 1063 } 1064 case CK_UncheckedDerivedToBase: 1065 case CK_DerivedToBase: { 1066 const RecordType *DerivedClassTy = 1067 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 1068 CXXRecordDecl *DerivedClassDecl = 1069 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 1070 1071 return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl, 1072 CE->path_begin(), CE->path_end(), 1073 ShouldNullCheckClassCastValue(CE)); 1074 } 1075 case CK_Dynamic: { 1076 Value *V = Visit(const_cast<Expr*>(E)); 1077 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 1078 return CGF.EmitDynamicCast(V, DCE); 1079 } 1080 1081 case CK_ArrayToPointerDecay: { 1082 assert(E->getType()->isArrayType() && 1083 "Array to pointer decay must have array source type!"); 1084 1085 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 1086 1087 // Note that VLA pointers are always decayed, so we don't need to do 1088 // anything here. 1089 if (!E->getType()->isVariableArrayType()) { 1090 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 1091 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 1092 ->getElementType()) && 1093 "Expected pointer to array"); 1094 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 1095 } 1096 1097 // Make sure the array decay ends up being the right type. This matters if 1098 // the array type was of an incomplete type. 1099 return CGF.Builder.CreateBitCast(V, ConvertType(CE->getType())); 1100 } 1101 case CK_FunctionToPointerDecay: 1102 return EmitLValue(E).getAddress(); 1103 1104 case CK_NullToPointer: 1105 if (MustVisitNullValue(E)) 1106 (void) Visit(E); 1107 1108 return llvm::ConstantPointerNull::get( 1109 cast<llvm::PointerType>(ConvertType(DestTy))); 1110 1111 case CK_NullToMemberPointer: { 1112 if (MustVisitNullValue(E)) 1113 (void) Visit(E); 1114 1115 const MemberPointerType *MPT = CE->getType()->getAs<MemberPointerType>(); 1116 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 1117 } 1118 1119 case CK_ReinterpretMemberPointer: 1120 case CK_BaseToDerivedMemberPointer: 1121 case CK_DerivedToBaseMemberPointer: { 1122 Value *Src = Visit(E); 1123 1124 // Note that the AST doesn't distinguish between checked and 1125 // unchecked member pointer conversions, so we always have to 1126 // implement checked conversions here. This is inefficient when 1127 // actual control flow may be required in order to perform the 1128 // check, which it is for data member pointers (but not member 1129 // function pointers on Itanium and ARM). 1130 return CGF.CGM.getCXXABI().EmitMemberPointerConversion(CGF, CE, Src); 1131 } 1132 1133 case CK_ARCProduceObject: 1134 return CGF.EmitARCRetainScalarExpr(E); 1135 case CK_ARCConsumeObject: 1136 return CGF.EmitObjCConsumeObject(E->getType(), Visit(E)); 1137 case CK_ARCReclaimReturnedObject: { 1138 llvm::Value *value = Visit(E); 1139 value = CGF.EmitARCRetainAutoreleasedReturnValue(value); 1140 return CGF.EmitObjCConsumeObject(E->getType(), value); 1141 } 1142 case CK_ARCExtendBlockObject: 1143 return CGF.EmitARCExtendBlockObject(E); 1144 1145 case CK_CopyAndAutoreleaseBlockObject: 1146 return CGF.EmitBlockCopyAndAutorelease(Visit(E), E->getType()); 1147 1148 case CK_FloatingRealToComplex: 1149 case CK_FloatingComplexCast: 1150 case CK_IntegralRealToComplex: 1151 case CK_IntegralComplexCast: 1152 case CK_IntegralComplexToFloatingComplex: 1153 case CK_FloatingComplexToIntegralComplex: 1154 case CK_ConstructorConversion: 1155 case CK_ToUnion: 1156 llvm_unreachable("scalar cast to non-scalar value"); 1157 1158 case CK_LValueToRValue: 1159 assert(CGF.getContext().hasSameUnqualifiedType(E->getType(), DestTy)); 1160 assert(E->isGLValue() && "lvalue-to-rvalue applied to r-value!"); 1161 return Visit(const_cast<Expr*>(E)); 1162 1163 case CK_IntegralToPointer: { 1164 Value *Src = Visit(const_cast<Expr*>(E)); 1165 1166 // First, convert to the correct width so that we control the kind of 1167 // extension. 1168 llvm::Type *MiddleTy = CGF.IntPtrTy; 1169 bool InputSigned = E->getType()->isSignedIntegerOrEnumerationType(); 1170 llvm::Value* IntResult = 1171 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 1172 1173 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 1174 } 1175 case CK_PointerToIntegral: 1176 assert(!DestTy->isBooleanType() && "bool should use PointerToBool"); 1177 return Builder.CreatePtrToInt(Visit(E), ConvertType(DestTy)); 1178 1179 case CK_ToVoid: { 1180 CGF.EmitIgnoredExpr(E); 1181 return 0; 1182 } 1183 case CK_VectorSplat: { 1184 llvm::Type *DstTy = ConvertType(DestTy); 1185 Value *Elt = Visit(const_cast<Expr*>(E)); 1186 Elt = EmitScalarConversion(Elt, E->getType(), 1187 DestTy->getAs<VectorType>()->getElementType()); 1188 1189 // Insert the element in element zero of an undef vector 1190 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 1191 llvm::Value *Idx = Builder.getInt32(0); 1192 UnV = Builder.CreateInsertElement(UnV, Elt, Idx); 1193 1194 // Splat the element across to all elements 1195 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 1196 llvm::Constant *Zero = Builder.getInt32(0); 1197 llvm::Constant *Mask = llvm::ConstantVector::getSplat(NumElements, Zero); 1198 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 1199 return Yay; 1200 } 1201 1202 case CK_IntegralCast: 1203 case CK_IntegralToFloating: 1204 case CK_FloatingToIntegral: 1205 case CK_FloatingCast: 1206 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 1207 case CK_IntegralToBoolean: 1208 return EmitIntToBoolConversion(Visit(E)); 1209 case CK_PointerToBoolean: 1210 return EmitPointerToBoolConversion(Visit(E)); 1211 case CK_FloatingToBoolean: 1212 return EmitFloatToBoolConversion(Visit(E)); 1213 case CK_MemberPointerToBoolean: { 1214 llvm::Value *MemPtr = Visit(E); 1215 const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>(); 1216 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT); 1217 } 1218 1219 case CK_FloatingComplexToReal: 1220 case CK_IntegralComplexToReal: 1221 return CGF.EmitComplexExpr(E, false, true).first; 1222 1223 case CK_FloatingComplexToBoolean: 1224 case CK_IntegralComplexToBoolean: { 1225 CodeGenFunction::ComplexPairTy V = CGF.EmitComplexExpr(E); 1226 1227 // TODO: kill this function off, inline appropriate case here 1228 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 1229 } 1230 1231 } 1232 1233 llvm_unreachable("unknown scalar cast"); 1234 } 1235 1236 Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 1237 CodeGenFunction::StmtExprEvaluation eval(CGF); 1238 return CGF.EmitCompoundStmt(*E->getSubStmt(), !E->getType()->isVoidType()) 1239 .getScalarVal(); 1240 } 1241 1242 //===----------------------------------------------------------------------===// 1243 // Unary Operators 1244 //===----------------------------------------------------------------------===// 1245 1246 llvm::Value *ScalarExprEmitter:: 1247 EmitAddConsiderOverflowBehavior(const UnaryOperator *E, 1248 llvm::Value *InVal, 1249 llvm::Value *NextVal, bool IsInc) { 1250 switch (CGF.getContext().getLangOpts().getSignedOverflowBehavior()) { 1251 case LangOptions::SOB_Undefined: 1252 return Builder.CreateNSWAdd(InVal, NextVal, IsInc ? "inc" : "dec"); 1253 case LangOptions::SOB_Defined: 1254 return Builder.CreateAdd(InVal, NextVal, IsInc ? "inc" : "dec"); 1255 case LangOptions::SOB_Trapping: 1256 BinOpInfo BinOp; 1257 BinOp.LHS = InVal; 1258 BinOp.RHS = NextVal; 1259 BinOp.Ty = E->getType(); 1260 BinOp.Opcode = BO_Add; 1261 BinOp.E = E; 1262 return EmitOverflowCheckedBinOp(BinOp); 1263 } 1264 llvm_unreachable("Unknown SignedOverflowBehaviorTy"); 1265 } 1266 1267 llvm::Value * 1268 ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 1269 bool isInc, bool isPre) { 1270 1271 QualType type = E->getSubExpr()->getType(); 1272 llvm::Value *value = EmitLoadOfLValue(LV); 1273 llvm::Value *input = value; 1274 llvm::PHINode *atomicPHI = 0; 1275 1276 int amount = (isInc ? 1 : -1); 1277 1278 if (const AtomicType *atomicTy = type->getAs<AtomicType>()) { 1279 llvm::BasicBlock *startBB = Builder.GetInsertBlock(); 1280 llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn); 1281 Builder.CreateBr(opBB); 1282 Builder.SetInsertPoint(opBB); 1283 atomicPHI = Builder.CreatePHI(value->getType(), 2); 1284 atomicPHI->addIncoming(value, startBB); 1285 type = atomicTy->getValueType(); 1286 value = atomicPHI; 1287 } 1288 1289 // Special case of integer increment that we have to check first: bool++. 1290 // Due to promotion rules, we get: 1291 // bool++ -> bool = bool + 1 1292 // -> bool = (int)bool + 1 1293 // -> bool = ((int)bool + 1 != 0) 1294 // An interesting aspect of this is that increment is always true. 1295 // Decrement does not have this property. 1296 if (isInc && type->isBooleanType()) { 1297 value = Builder.getTrue(); 1298 1299 // Most common case by far: integer increment. 1300 } else if (type->isIntegerType()) { 1301 1302 llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount); 1303 1304 // Note that signed integer inc/dec with width less than int can't 1305 // overflow because of promotion rules; we're just eliding a few steps here. 1306 if (type->isSignedIntegerOrEnumerationType() && 1307 value->getType()->getPrimitiveSizeInBits() >= 1308 CGF.IntTy->getBitWidth()) 1309 value = EmitAddConsiderOverflowBehavior(E, value, amt, isInc); 1310 else 1311 value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec"); 1312 1313 // Next most common: pointer increment. 1314 } else if (const PointerType *ptr = type->getAs<PointerType>()) { 1315 QualType type = ptr->getPointeeType(); 1316 1317 // VLA types don't have constant size. 1318 if (const VariableArrayType *vla 1319 = CGF.getContext().getAsVariableArrayType(type)) { 1320 llvm::Value *numElts = CGF.getVLASize(vla).first; 1321 if (!isInc) numElts = Builder.CreateNSWNeg(numElts, "vla.negsize"); 1322 if (CGF.getContext().getLangOpts().isSignedOverflowDefined()) 1323 value = Builder.CreateGEP(value, numElts, "vla.inc"); 1324 else 1325 value = Builder.CreateInBoundsGEP(value, numElts, "vla.inc"); 1326 1327 // Arithmetic on function pointers (!) is just +-1. 1328 } else if (type->isFunctionType()) { 1329 llvm::Value *amt = Builder.getInt32(amount); 1330 1331 value = CGF.EmitCastToVoidPtr(value); 1332 if (CGF.getContext().getLangOpts().isSignedOverflowDefined()) 1333 value = Builder.CreateGEP(value, amt, "incdec.funcptr"); 1334 else 1335 value = Builder.CreateInBoundsGEP(value, amt, "incdec.funcptr"); 1336 value = Builder.CreateBitCast(value, input->getType()); 1337 1338 // For everything else, we can just do a simple increment. 1339 } else { 1340 llvm::Value *amt = Builder.getInt32(amount); 1341 if (CGF.getContext().getLangOpts().isSignedOverflowDefined()) 1342 value = Builder.CreateGEP(value, amt, "incdec.ptr"); 1343 else 1344 value = Builder.CreateInBoundsGEP(value, amt, "incdec.ptr"); 1345 } 1346 1347 // Vector increment/decrement. 1348 } else if (type->isVectorType()) { 1349 if (type->hasIntegerRepresentation()) { 1350 llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount); 1351 1352 value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec"); 1353 } else { 1354 value = Builder.CreateFAdd( 1355 value, 1356 llvm::ConstantFP::get(value->getType(), amount), 1357 isInc ? "inc" : "dec"); 1358 } 1359 1360 // Floating point. 1361 } else if (type->isRealFloatingType()) { 1362 // Add the inc/dec to the real part. 1363 llvm::Value *amt; 1364 1365 if (type->isHalfType()) { 1366 // Another special case: half FP increment should be done via float 1367 value = 1368 Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16), 1369 input); 1370 } 1371 1372 if (value->getType()->isFloatTy()) 1373 amt = llvm::ConstantFP::get(VMContext, 1374 llvm::APFloat(static_cast<float>(amount))); 1375 else if (value->getType()->isDoubleTy()) 1376 amt = llvm::ConstantFP::get(VMContext, 1377 llvm::APFloat(static_cast<double>(amount))); 1378 else { 1379 llvm::APFloat F(static_cast<float>(amount)); 1380 bool ignored; 1381 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, 1382 &ignored); 1383 amt = llvm::ConstantFP::get(VMContext, F); 1384 } 1385 value = Builder.CreateFAdd(value, amt, isInc ? "inc" : "dec"); 1386 1387 if (type->isHalfType()) 1388 value = 1389 Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16), 1390 value); 1391 1392 // Objective-C pointer types. 1393 } else { 1394 const ObjCObjectPointerType *OPT = type->castAs<ObjCObjectPointerType>(); 1395 value = CGF.EmitCastToVoidPtr(value); 1396 1397 CharUnits size = CGF.getContext().getTypeSizeInChars(OPT->getObjectType()); 1398 if (!isInc) size = -size; 1399 llvm::Value *sizeValue = 1400 llvm::ConstantInt::get(CGF.SizeTy, size.getQuantity()); 1401 1402 if (CGF.getContext().getLangOpts().isSignedOverflowDefined()) 1403 value = Builder.CreateGEP(value, sizeValue, "incdec.objptr"); 1404 else 1405 value = Builder.CreateInBoundsGEP(value, sizeValue, "incdec.objptr"); 1406 value = Builder.CreateBitCast(value, input->getType()); 1407 } 1408 1409 if (atomicPHI) { 1410 llvm::BasicBlock *opBB = Builder.GetInsertBlock(); 1411 llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn); 1412 llvm::Value *old = Builder.CreateAtomicCmpXchg(LV.getAddress(), atomicPHI, 1413 value, llvm::SequentiallyConsistent); 1414 atomicPHI->addIncoming(old, opBB); 1415 llvm::Value *success = Builder.CreateICmpEQ(old, atomicPHI); 1416 Builder.CreateCondBr(success, contBB, opBB); 1417 Builder.SetInsertPoint(contBB); 1418 return isPre ? value : input; 1419 } 1420 1421 // Store the updated result through the lvalue. 1422 if (LV.isBitField()) 1423 CGF.EmitStoreThroughBitfieldLValue(RValue::get(value), LV, &value); 1424 else 1425 CGF.EmitStoreThroughLValue(RValue::get(value), LV); 1426 1427 // If this is a postinc, return the value read from memory, otherwise use the 1428 // updated value. 1429 return isPre ? value : input; 1430 } 1431 1432 1433 1434 Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1435 TestAndClearIgnoreResultAssign(); 1436 // Emit unary minus with EmitSub so we handle overflow cases etc. 1437 BinOpInfo BinOp; 1438 BinOp.RHS = Visit(E->getSubExpr()); 1439 1440 if (BinOp.RHS->getType()->isFPOrFPVectorTy()) 1441 BinOp.LHS = llvm::ConstantFP::getZeroValueForNegation(BinOp.RHS->getType()); 1442 else 1443 BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType()); 1444 BinOp.Ty = E->getType(); 1445 BinOp.Opcode = BO_Sub; 1446 BinOp.E = E; 1447 return EmitSub(BinOp); 1448 } 1449 1450 Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1451 TestAndClearIgnoreResultAssign(); 1452 Value *Op = Visit(E->getSubExpr()); 1453 return Builder.CreateNot(Op, "neg"); 1454 } 1455 1456 Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1457 1458 // Perform vector logical not on comparison with zero vector. 1459 if (E->getType()->isExtVectorType()) { 1460 Value *Oper = Visit(E->getSubExpr()); 1461 Value *Zero = llvm::Constant::getNullValue(Oper->getType()); 1462 Value *Result = Builder.CreateICmp(llvm::CmpInst::ICMP_EQ, Oper, Zero, "cmp"); 1463 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 1464 } 1465 1466 // Compare operand to zero. 1467 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1468 1469 // Invert value. 1470 // TODO: Could dynamically modify easy computations here. For example, if 1471 // the operand is an icmp ne, turn into icmp eq. 1472 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1473 1474 // ZExt result to the expr type. 1475 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1476 } 1477 1478 Value *ScalarExprEmitter::VisitOffsetOfExpr(OffsetOfExpr *E) { 1479 // Try folding the offsetof to a constant. 1480 llvm::APSInt Value; 1481 if (E->EvaluateAsInt(Value, CGF.getContext())) 1482 return Builder.getInt(Value); 1483 1484 // Loop over the components of the offsetof to compute the value. 1485 unsigned n = E->getNumComponents(); 1486 llvm::Type* ResultType = ConvertType(E->getType()); 1487 llvm::Value* Result = llvm::Constant::getNullValue(ResultType); 1488 QualType CurrentType = E->getTypeSourceInfo()->getType(); 1489 for (unsigned i = 0; i != n; ++i) { 1490 OffsetOfExpr::OffsetOfNode ON = E->getComponent(i); 1491 llvm::Value *Offset = 0; 1492 switch (ON.getKind()) { 1493 case OffsetOfExpr::OffsetOfNode::Array: { 1494 // Compute the index 1495 Expr *IdxExpr = E->getIndexExpr(ON.getArrayExprIndex()); 1496 llvm::Value* Idx = CGF.EmitScalarExpr(IdxExpr); 1497 bool IdxSigned = IdxExpr->getType()->isSignedIntegerOrEnumerationType(); 1498 Idx = Builder.CreateIntCast(Idx, ResultType, IdxSigned, "conv"); 1499 1500 // Save the element type 1501 CurrentType = 1502 CGF.getContext().getAsArrayType(CurrentType)->getElementType(); 1503 1504 // Compute the element size 1505 llvm::Value* ElemSize = llvm::ConstantInt::get(ResultType, 1506 CGF.getContext().getTypeSizeInChars(CurrentType).getQuantity()); 1507 1508 // Multiply out to compute the result 1509 Offset = Builder.CreateMul(Idx, ElemSize); 1510 break; 1511 } 1512 1513 case OffsetOfExpr::OffsetOfNode::Field: { 1514 FieldDecl *MemberDecl = ON.getField(); 1515 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1516 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1517 1518 // Compute the index of the field in its parent. 1519 unsigned i = 0; 1520 // FIXME: It would be nice if we didn't have to loop here! 1521 for (RecordDecl::field_iterator Field = RD->field_begin(), 1522 FieldEnd = RD->field_end(); 1523 Field != FieldEnd; (void)++Field, ++i) { 1524 if (*Field == MemberDecl) 1525 break; 1526 } 1527 assert(i < RL.getFieldCount() && "offsetof field in wrong type"); 1528 1529 // Compute the offset to the field 1530 int64_t OffsetInt = RL.getFieldOffset(i) / 1531 CGF.getContext().getCharWidth(); 1532 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1533 1534 // Save the element type. 1535 CurrentType = MemberDecl->getType(); 1536 break; 1537 } 1538 1539 case OffsetOfExpr::OffsetOfNode::Identifier: 1540 llvm_unreachable("dependent __builtin_offsetof"); 1541 1542 case OffsetOfExpr::OffsetOfNode::Base: { 1543 if (ON.getBase()->isVirtual()) { 1544 CGF.ErrorUnsupported(E, "virtual base in offsetof"); 1545 continue; 1546 } 1547 1548 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1549 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1550 1551 // Save the element type. 1552 CurrentType = ON.getBase()->getType(); 1553 1554 // Compute the offset to the base. 1555 const RecordType *BaseRT = CurrentType->getAs<RecordType>(); 1556 CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl()); 1557 int64_t OffsetInt = RL.getBaseClassOffsetInBits(BaseRD) / 1558 CGF.getContext().getCharWidth(); 1559 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1560 break; 1561 } 1562 } 1563 Result = Builder.CreateAdd(Result, Offset); 1564 } 1565 return Result; 1566 } 1567 1568 /// VisitUnaryExprOrTypeTraitExpr - Return the size or alignment of the type of 1569 /// argument of the sizeof expression as an integer. 1570 Value * 1571 ScalarExprEmitter::VisitUnaryExprOrTypeTraitExpr( 1572 const UnaryExprOrTypeTraitExpr *E) { 1573 QualType TypeToSize = E->getTypeOfArgument(); 1574 if (E->getKind() == UETT_SizeOf) { 1575 if (const VariableArrayType *VAT = 1576 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1577 if (E->isArgumentType()) { 1578 // sizeof(type) - make sure to emit the VLA size. 1579 CGF.EmitVariablyModifiedType(TypeToSize); 1580 } else { 1581 // C99 6.5.3.4p2: If the argument is an expression of type 1582 // VLA, it is evaluated. 1583 CGF.EmitIgnoredExpr(E->getArgumentExpr()); 1584 } 1585 1586 QualType eltType; 1587 llvm::Value *numElts; 1588 llvm::tie(numElts, eltType) = CGF.getVLASize(VAT); 1589 1590 llvm::Value *size = numElts; 1591 1592 // Scale the number of non-VLA elements by the non-VLA element size. 1593 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType); 1594 if (!eltSize.isOne()) 1595 size = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), numElts); 1596 1597 return size; 1598 } 1599 } 1600 1601 // If this isn't sizeof(vla), the result must be constant; use the constant 1602 // folding logic so we don't have to duplicate it here. 1603 return Builder.getInt(E->EvaluateKnownConstInt(CGF.getContext())); 1604 } 1605 1606 Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1607 Expr *Op = E->getSubExpr(); 1608 if (Op->getType()->isAnyComplexType()) { 1609 // If it's an l-value, load through the appropriate subobject l-value. 1610 // Note that we have to ask E because Op might be an l-value that 1611 // this won't work for, e.g. an Obj-C property. 1612 if (E->isGLValue()) 1613 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E)).getScalarVal(); 1614 1615 // Otherwise, calculate and project. 1616 return CGF.EmitComplexExpr(Op, false, true).first; 1617 } 1618 1619 return Visit(Op); 1620 } 1621 1622 Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1623 Expr *Op = E->getSubExpr(); 1624 if (Op->getType()->isAnyComplexType()) { 1625 // If it's an l-value, load through the appropriate subobject l-value. 1626 // Note that we have to ask E because Op might be an l-value that 1627 // this won't work for, e.g. an Obj-C property. 1628 if (Op->isGLValue()) 1629 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E)).getScalarVal(); 1630 1631 // Otherwise, calculate and project. 1632 return CGF.EmitComplexExpr(Op, true, false).second; 1633 } 1634 1635 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1636 // effects are evaluated, but not the actual value. 1637 if (Op->isGLValue()) 1638 CGF.EmitLValue(Op); 1639 else 1640 CGF.EmitScalarExpr(Op, true); 1641 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1642 } 1643 1644 //===----------------------------------------------------------------------===// 1645 // Binary Operators 1646 //===----------------------------------------------------------------------===// 1647 1648 BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1649 TestAndClearIgnoreResultAssign(); 1650 BinOpInfo Result; 1651 Result.LHS = Visit(E->getLHS()); 1652 Result.RHS = Visit(E->getRHS()); 1653 Result.Ty = E->getType(); 1654 Result.Opcode = E->getOpcode(); 1655 Result.E = E; 1656 return Result; 1657 } 1658 1659 LValue ScalarExprEmitter::EmitCompoundAssignLValue( 1660 const CompoundAssignOperator *E, 1661 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &), 1662 Value *&Result) { 1663 QualType LHSTy = E->getLHS()->getType(); 1664 BinOpInfo OpInfo; 1665 1666 if (E->getComputationResultType()->isAnyComplexType()) { 1667 // This needs to go through the complex expression emitter, but it's a tad 1668 // complicated to do that... I'm leaving it out for now. (Note that we do 1669 // actually need the imaginary part of the RHS for multiplication and 1670 // division.) 1671 CGF.ErrorUnsupported(E, "complex compound assignment"); 1672 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType())); 1673 return LValue(); 1674 } 1675 1676 // Emit the RHS first. __block variables need to have the rhs evaluated 1677 // first, plus this should improve codegen a little. 1678 OpInfo.RHS = Visit(E->getRHS()); 1679 OpInfo.Ty = E->getComputationResultType(); 1680 OpInfo.Opcode = E->getOpcode(); 1681 OpInfo.E = E; 1682 // Load/convert the LHS. 1683 LValue LHSLV = EmitCheckedLValue(E->getLHS()); 1684 OpInfo.LHS = EmitLoadOfLValue(LHSLV); 1685 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 1686 E->getComputationLHSType()); 1687 1688 llvm::PHINode *atomicPHI = 0; 1689 if (const AtomicType *atomicTy = OpInfo.Ty->getAs<AtomicType>()) { 1690 // FIXME: For floating point types, we should be saving and restoring the 1691 // floating point environment in the loop. 1692 llvm::BasicBlock *startBB = Builder.GetInsertBlock(); 1693 llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn); 1694 Builder.CreateBr(opBB); 1695 Builder.SetInsertPoint(opBB); 1696 atomicPHI = Builder.CreatePHI(OpInfo.LHS->getType(), 2); 1697 atomicPHI->addIncoming(OpInfo.LHS, startBB); 1698 OpInfo.Ty = atomicTy->getValueType(); 1699 OpInfo.LHS = atomicPHI; 1700 } 1701 1702 // Expand the binary operator. 1703 Result = (this->*Func)(OpInfo); 1704 1705 // Convert the result back to the LHS type. 1706 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 1707 1708 if (atomicPHI) { 1709 llvm::BasicBlock *opBB = Builder.GetInsertBlock(); 1710 llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn); 1711 llvm::Value *old = Builder.CreateAtomicCmpXchg(LHSLV.getAddress(), atomicPHI, 1712 Result, llvm::SequentiallyConsistent); 1713 atomicPHI->addIncoming(old, opBB); 1714 llvm::Value *success = Builder.CreateICmpEQ(old, atomicPHI); 1715 Builder.CreateCondBr(success, contBB, opBB); 1716 Builder.SetInsertPoint(contBB); 1717 return LHSLV; 1718 } 1719 1720 // Store the result value into the LHS lvalue. Bit-fields are handled 1721 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 1722 // 'An assignment expression has the value of the left operand after the 1723 // assignment...'. 1724 if (LHSLV.isBitField()) 1725 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, &Result); 1726 else 1727 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV); 1728 1729 return LHSLV; 1730 } 1731 1732 Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 1733 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 1734 bool Ignore = TestAndClearIgnoreResultAssign(); 1735 Value *RHS; 1736 LValue LHS = EmitCompoundAssignLValue(E, Func, RHS); 1737 1738 // If the result is clearly ignored, return now. 1739 if (Ignore) 1740 return 0; 1741 1742 // The result of an assignment in C is the assigned r-value. 1743 if (!CGF.getContext().getLangOpts().CPlusPlus) 1744 return RHS; 1745 1746 // If the lvalue is non-volatile, return the computed value of the assignment. 1747 if (!LHS.isVolatileQualified()) 1748 return RHS; 1749 1750 // Otherwise, reload the value. 1751 return EmitLoadOfLValue(LHS); 1752 } 1753 1754 void ScalarExprEmitter::EmitUndefinedBehaviorIntegerDivAndRemCheck( 1755 const BinOpInfo &Ops, 1756 llvm::Value *Zero, bool isDiv) { 1757 llvm::Function::iterator insertPt = Builder.GetInsertBlock(); 1758 llvm::BasicBlock *contBB = 1759 CGF.createBasicBlock(isDiv ? "div.cont" : "rem.cont", CGF.CurFn, 1760 llvm::next(insertPt)); 1761 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); 1762 1763 llvm::IntegerType *Ty = cast<llvm::IntegerType>(Zero->getType()); 1764 1765 if (Ops.Ty->hasSignedIntegerRepresentation()) { 1766 llvm::Value *IntMin = 1767 Builder.getInt(llvm::APInt::getSignedMinValue(Ty->getBitWidth())); 1768 llvm::Value *NegOne = llvm::ConstantInt::get(Ty, -1ULL); 1769 1770 llvm::Value *Cond1 = Builder.CreateICmpEQ(Ops.RHS, Zero); 1771 llvm::Value *LHSCmp = Builder.CreateICmpEQ(Ops.LHS, IntMin); 1772 llvm::Value *RHSCmp = Builder.CreateICmpEQ(Ops.RHS, NegOne); 1773 llvm::Value *Cond2 = Builder.CreateAnd(LHSCmp, RHSCmp, "and"); 1774 Builder.CreateCondBr(Builder.CreateOr(Cond1, Cond2, "or"), 1775 overflowBB, contBB); 1776 } else { 1777 CGF.Builder.CreateCondBr(Builder.CreateICmpEQ(Ops.RHS, Zero), 1778 overflowBB, contBB); 1779 } 1780 EmitOverflowBB(overflowBB); 1781 Builder.SetInsertPoint(contBB); 1782 } 1783 1784 Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 1785 if (isTrapvOverflowBehavior()) { 1786 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 1787 1788 if (Ops.Ty->isIntegerType()) 1789 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, true); 1790 else if (Ops.Ty->isRealFloatingType()) { 1791 llvm::Function::iterator insertPt = Builder.GetInsertBlock(); 1792 llvm::BasicBlock *DivCont = CGF.createBasicBlock("div.cont", CGF.CurFn, 1793 llvm::next(insertPt)); 1794 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", 1795 CGF.CurFn); 1796 CGF.Builder.CreateCondBr(Builder.CreateFCmpOEQ(Ops.RHS, Zero), 1797 overflowBB, DivCont); 1798 EmitOverflowBB(overflowBB); 1799 Builder.SetInsertPoint(DivCont); 1800 } 1801 } 1802 if (Ops.LHS->getType()->isFPOrFPVectorTy()) { 1803 llvm::Value *Val = Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 1804 if (CGF.getContext().getLangOpts().OpenCL) { 1805 // OpenCL 1.1 7.4: minimum accuracy of single precision / is 2.5ulp 1806 llvm::Type *ValTy = Val->getType(); 1807 if (ValTy->isFloatTy() || 1808 (isa<llvm::VectorType>(ValTy) && 1809 cast<llvm::VectorType>(ValTy)->getElementType()->isFloatTy())) 1810 CGF.SetFPAccuracy(Val, 2.5); 1811 } 1812 return Val; 1813 } 1814 else if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1815 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 1816 else 1817 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 1818 } 1819 1820 Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 1821 // Rem in C can't be a floating point type: C99 6.5.5p2. 1822 if (isTrapvOverflowBehavior()) { 1823 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 1824 1825 if (Ops.Ty->isIntegerType()) 1826 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, false); 1827 } 1828 1829 if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1830 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 1831 else 1832 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 1833 } 1834 1835 Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 1836 unsigned IID; 1837 unsigned OpID = 0; 1838 1839 switch (Ops.Opcode) { 1840 case BO_Add: 1841 case BO_AddAssign: 1842 OpID = 1; 1843 IID = llvm::Intrinsic::sadd_with_overflow; 1844 break; 1845 case BO_Sub: 1846 case BO_SubAssign: 1847 OpID = 2; 1848 IID = llvm::Intrinsic::ssub_with_overflow; 1849 break; 1850 case BO_Mul: 1851 case BO_MulAssign: 1852 OpID = 3; 1853 IID = llvm::Intrinsic::smul_with_overflow; 1854 break; 1855 default: 1856 llvm_unreachable("Unsupported operation for overflow detection"); 1857 } 1858 OpID <<= 1; 1859 OpID |= 1; 1860 1861 llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1862 1863 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, opTy); 1864 1865 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1866 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1867 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1868 1869 // Branch in case of overflow. 1870 llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); 1871 llvm::Function::iterator insertPt = initialBB; 1872 llvm::BasicBlock *continueBB = CGF.createBasicBlock("nooverflow", CGF.CurFn, 1873 llvm::next(insertPt)); 1874 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); 1875 1876 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1877 1878 // Handle overflow with llvm.trap. 1879 const std::string *handlerName = 1880 &CGF.getContext().getLangOpts().OverflowHandler; 1881 if (handlerName->empty()) { 1882 EmitOverflowBB(overflowBB); 1883 Builder.SetInsertPoint(continueBB); 1884 return result; 1885 } 1886 1887 // If an overflow handler is set, then we want to call it and then use its 1888 // result, if it returns. 1889 Builder.SetInsertPoint(overflowBB); 1890 1891 // Get the overflow handler. 1892 llvm::Type *Int8Ty = CGF.Int8Ty; 1893 llvm::Type *argTypes[] = { CGF.Int64Ty, CGF.Int64Ty, Int8Ty, Int8Ty }; 1894 llvm::FunctionType *handlerTy = 1895 llvm::FunctionType::get(CGF.Int64Ty, argTypes, true); 1896 llvm::Value *handler = CGF.CGM.CreateRuntimeFunction(handlerTy, *handlerName); 1897 1898 // Sign extend the args to 64-bit, so that we can use the same handler for 1899 // all types of overflow. 1900 llvm::Value *lhs = Builder.CreateSExt(Ops.LHS, CGF.Int64Ty); 1901 llvm::Value *rhs = Builder.CreateSExt(Ops.RHS, CGF.Int64Ty); 1902 1903 // Call the handler with the two arguments, the operation, and the size of 1904 // the result. 1905 llvm::Value *handlerResult = Builder.CreateCall4(handler, lhs, rhs, 1906 Builder.getInt8(OpID), 1907 Builder.getInt8(cast<llvm::IntegerType>(opTy)->getBitWidth())); 1908 1909 // Truncate the result back to the desired size. 1910 handlerResult = Builder.CreateTrunc(handlerResult, opTy); 1911 Builder.CreateBr(continueBB); 1912 1913 Builder.SetInsertPoint(continueBB); 1914 llvm::PHINode *phi = Builder.CreatePHI(opTy, 2); 1915 phi->addIncoming(result, initialBB); 1916 phi->addIncoming(handlerResult, overflowBB); 1917 1918 return phi; 1919 } 1920 1921 /// Emit pointer + index arithmetic. 1922 static Value *emitPointerArithmetic(CodeGenFunction &CGF, 1923 const BinOpInfo &op, 1924 bool isSubtraction) { 1925 // Must have binary (not unary) expr here. Unary pointer 1926 // increment/decrement doesn't use this path. 1927 const BinaryOperator *expr = cast<BinaryOperator>(op.E); 1928 1929 Value *pointer = op.LHS; 1930 Expr *pointerOperand = expr->getLHS(); 1931 Value *index = op.RHS; 1932 Expr *indexOperand = expr->getRHS(); 1933 1934 // In a subtraction, the LHS is always the pointer. 1935 if (!isSubtraction && !pointer->getType()->isPointerTy()) { 1936 std::swap(pointer, index); 1937 std::swap(pointerOperand, indexOperand); 1938 } 1939 1940 unsigned width = cast<llvm::IntegerType>(index->getType())->getBitWidth(); 1941 if (width != CGF.PointerWidthInBits) { 1942 // Zero-extend or sign-extend the pointer value according to 1943 // whether the index is signed or not. 1944 bool isSigned = indexOperand->getType()->isSignedIntegerOrEnumerationType(); 1945 index = CGF.Builder.CreateIntCast(index, CGF.PtrDiffTy, isSigned, 1946 "idx.ext"); 1947 } 1948 1949 // If this is subtraction, negate the index. 1950 if (isSubtraction) 1951 index = CGF.Builder.CreateNeg(index, "idx.neg"); 1952 1953 const PointerType *pointerType 1954 = pointerOperand->getType()->getAs<PointerType>(); 1955 if (!pointerType) { 1956 QualType objectType = pointerOperand->getType() 1957 ->castAs<ObjCObjectPointerType>() 1958 ->getPointeeType(); 1959 llvm::Value *objectSize 1960 = CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(objectType)); 1961 1962 index = CGF.Builder.CreateMul(index, objectSize); 1963 1964 Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy); 1965 result = CGF.Builder.CreateGEP(result, index, "add.ptr"); 1966 return CGF.Builder.CreateBitCast(result, pointer->getType()); 1967 } 1968 1969 QualType elementType = pointerType->getPointeeType(); 1970 if (const VariableArrayType *vla 1971 = CGF.getContext().getAsVariableArrayType(elementType)) { 1972 // The element count here is the total number of non-VLA elements. 1973 llvm::Value *numElements = CGF.getVLASize(vla).first; 1974 1975 // Effectively, the multiply by the VLA size is part of the GEP. 1976 // GEP indexes are signed, and scaling an index isn't permitted to 1977 // signed-overflow, so we use the same semantics for our explicit 1978 // multiply. We suppress this if overflow is not undefined behavior. 1979 if (CGF.getLangOpts().isSignedOverflowDefined()) { 1980 index = CGF.Builder.CreateMul(index, numElements, "vla.index"); 1981 pointer = CGF.Builder.CreateGEP(pointer, index, "add.ptr"); 1982 } else { 1983 index = CGF.Builder.CreateNSWMul(index, numElements, "vla.index"); 1984 pointer = CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr"); 1985 } 1986 return pointer; 1987 } 1988 1989 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 1990 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 1991 // future proof. 1992 if (elementType->isVoidType() || elementType->isFunctionType()) { 1993 Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy); 1994 result = CGF.Builder.CreateGEP(result, index, "add.ptr"); 1995 return CGF.Builder.CreateBitCast(result, pointer->getType()); 1996 } 1997 1998 if (CGF.getLangOpts().isSignedOverflowDefined()) 1999 return CGF.Builder.CreateGEP(pointer, index, "add.ptr"); 2000 2001 return CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr"); 2002 } 2003 2004 Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &op) { 2005 if (op.LHS->getType()->isPointerTy() || 2006 op.RHS->getType()->isPointerTy()) 2007 return emitPointerArithmetic(CGF, op, /*subtraction*/ false); 2008 2009 if (op.Ty->isSignedIntegerOrEnumerationType()) { 2010 switch (CGF.getContext().getLangOpts().getSignedOverflowBehavior()) { 2011 case LangOptions::SOB_Undefined: 2012 return Builder.CreateNSWAdd(op.LHS, op.RHS, "add"); 2013 case LangOptions::SOB_Defined: 2014 return Builder.CreateAdd(op.LHS, op.RHS, "add"); 2015 case LangOptions::SOB_Trapping: 2016 return EmitOverflowCheckedBinOp(op); 2017 } 2018 } 2019 2020 if (op.LHS->getType()->isFPOrFPVectorTy()) 2021 return Builder.CreateFAdd(op.LHS, op.RHS, "add"); 2022 2023 return Builder.CreateAdd(op.LHS, op.RHS, "add"); 2024 } 2025 2026 Value *ScalarExprEmitter::EmitSub(const BinOpInfo &op) { 2027 // The LHS is always a pointer if either side is. 2028 if (!op.LHS->getType()->isPointerTy()) { 2029 if (op.Ty->isSignedIntegerOrEnumerationType()) { 2030 switch (CGF.getContext().getLangOpts().getSignedOverflowBehavior()) { 2031 case LangOptions::SOB_Undefined: 2032 return Builder.CreateNSWSub(op.LHS, op.RHS, "sub"); 2033 case LangOptions::SOB_Defined: 2034 return Builder.CreateSub(op.LHS, op.RHS, "sub"); 2035 case LangOptions::SOB_Trapping: 2036 return EmitOverflowCheckedBinOp(op); 2037 } 2038 } 2039 2040 if (op.LHS->getType()->isFPOrFPVectorTy()) 2041 return Builder.CreateFSub(op.LHS, op.RHS, "sub"); 2042 2043 return Builder.CreateSub(op.LHS, op.RHS, "sub"); 2044 } 2045 2046 // If the RHS is not a pointer, then we have normal pointer 2047 // arithmetic. 2048 if (!op.RHS->getType()->isPointerTy()) 2049 return emitPointerArithmetic(CGF, op, /*subtraction*/ true); 2050 2051 // Otherwise, this is a pointer subtraction. 2052 2053 // Do the raw subtraction part. 2054 llvm::Value *LHS 2055 = Builder.CreatePtrToInt(op.LHS, CGF.PtrDiffTy, "sub.ptr.lhs.cast"); 2056 llvm::Value *RHS 2057 = Builder.CreatePtrToInt(op.RHS, CGF.PtrDiffTy, "sub.ptr.rhs.cast"); 2058 Value *diffInChars = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 2059 2060 // Okay, figure out the element size. 2061 const BinaryOperator *expr = cast<BinaryOperator>(op.E); 2062 QualType elementType = expr->getLHS()->getType()->getPointeeType(); 2063 2064 llvm::Value *divisor = 0; 2065 2066 // For a variable-length array, this is going to be non-constant. 2067 if (const VariableArrayType *vla 2068 = CGF.getContext().getAsVariableArrayType(elementType)) { 2069 llvm::Value *numElements; 2070 llvm::tie(numElements, elementType) = CGF.getVLASize(vla); 2071 2072 divisor = numElements; 2073 2074 // Scale the number of non-VLA elements by the non-VLA element size. 2075 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(elementType); 2076 if (!eltSize.isOne()) 2077 divisor = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), divisor); 2078 2079 // For everything elese, we can just compute it, safe in the 2080 // assumption that Sema won't let anything through that we can't 2081 // safely compute the size of. 2082 } else { 2083 CharUnits elementSize; 2084 // Handle GCC extension for pointer arithmetic on void* and 2085 // function pointer types. 2086 if (elementType->isVoidType() || elementType->isFunctionType()) 2087 elementSize = CharUnits::One(); 2088 else 2089 elementSize = CGF.getContext().getTypeSizeInChars(elementType); 2090 2091 // Don't even emit the divide for element size of 1. 2092 if (elementSize.isOne()) 2093 return diffInChars; 2094 2095 divisor = CGF.CGM.getSize(elementSize); 2096 } 2097 2098 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 2099 // pointer difference in C is only defined in the case where both operands 2100 // are pointing to elements of an array. 2101 return Builder.CreateExactSDiv(diffInChars, divisor, "sub.ptr.div"); 2102 } 2103 2104 Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 2105 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 2106 // RHS to the same size as the LHS. 2107 Value *RHS = Ops.RHS; 2108 if (Ops.LHS->getType() != RHS->getType()) 2109 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 2110 2111 if (CGF.CatchUndefined 2112 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 2113 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 2114 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 2115 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 2116 llvm::ConstantInt::get(RHS->getType(), Width)), 2117 Cont, CGF.getTrapBB()); 2118 CGF.EmitBlock(Cont); 2119 } 2120 2121 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 2122 } 2123 2124 Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 2125 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 2126 // RHS to the same size as the LHS. 2127 Value *RHS = Ops.RHS; 2128 if (Ops.LHS->getType() != RHS->getType()) 2129 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 2130 2131 if (CGF.CatchUndefined 2132 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 2133 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 2134 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 2135 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 2136 llvm::ConstantInt::get(RHS->getType(), Width)), 2137 Cont, CGF.getTrapBB()); 2138 CGF.EmitBlock(Cont); 2139 } 2140 2141 if (Ops.Ty->hasUnsignedIntegerRepresentation()) 2142 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 2143 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 2144 } 2145 2146 enum IntrinsicType { VCMPEQ, VCMPGT }; 2147 // return corresponding comparison intrinsic for given vector type 2148 static llvm::Intrinsic::ID GetIntrinsic(IntrinsicType IT, 2149 BuiltinType::Kind ElemKind) { 2150 switch (ElemKind) { 2151 default: llvm_unreachable("unexpected element type"); 2152 case BuiltinType::Char_U: 2153 case BuiltinType::UChar: 2154 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p : 2155 llvm::Intrinsic::ppc_altivec_vcmpgtub_p; 2156 case BuiltinType::Char_S: 2157 case BuiltinType::SChar: 2158 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p : 2159 llvm::Intrinsic::ppc_altivec_vcmpgtsb_p; 2160 case BuiltinType::UShort: 2161 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p : 2162 llvm::Intrinsic::ppc_altivec_vcmpgtuh_p; 2163 case BuiltinType::Short: 2164 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p : 2165 llvm::Intrinsic::ppc_altivec_vcmpgtsh_p; 2166 case BuiltinType::UInt: 2167 case BuiltinType::ULong: 2168 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p : 2169 llvm::Intrinsic::ppc_altivec_vcmpgtuw_p; 2170 case BuiltinType::Int: 2171 case BuiltinType::Long: 2172 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p : 2173 llvm::Intrinsic::ppc_altivec_vcmpgtsw_p; 2174 case BuiltinType::Float: 2175 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpeqfp_p : 2176 llvm::Intrinsic::ppc_altivec_vcmpgtfp_p; 2177 } 2178 } 2179 2180 Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 2181 unsigned SICmpOpc, unsigned FCmpOpc) { 2182 TestAndClearIgnoreResultAssign(); 2183 Value *Result; 2184 QualType LHSTy = E->getLHS()->getType(); 2185 if (const MemberPointerType *MPT = LHSTy->getAs<MemberPointerType>()) { 2186 assert(E->getOpcode() == BO_EQ || 2187 E->getOpcode() == BO_NE); 2188 Value *LHS = CGF.EmitScalarExpr(E->getLHS()); 2189 Value *RHS = CGF.EmitScalarExpr(E->getRHS()); 2190 Result = CGF.CGM.getCXXABI().EmitMemberPointerComparison( 2191 CGF, LHS, RHS, MPT, E->getOpcode() == BO_NE); 2192 } else if (!LHSTy->isAnyComplexType()) { 2193 Value *LHS = Visit(E->getLHS()); 2194 Value *RHS = Visit(E->getRHS()); 2195 2196 // If AltiVec, the comparison results in a numeric type, so we use 2197 // intrinsics comparing vectors and giving 0 or 1 as a result 2198 if (LHSTy->isVectorType() && !E->getType()->isVectorType()) { 2199 // constants for mapping CR6 register bits to predicate result 2200 enum { CR6_EQ=0, CR6_EQ_REV, CR6_LT, CR6_LT_REV } CR6; 2201 2202 llvm::Intrinsic::ID ID = llvm::Intrinsic::not_intrinsic; 2203 2204 // in several cases vector arguments order will be reversed 2205 Value *FirstVecArg = LHS, 2206 *SecondVecArg = RHS; 2207 2208 QualType ElTy = LHSTy->getAs<VectorType>()->getElementType(); 2209 const BuiltinType *BTy = ElTy->getAs<BuiltinType>(); 2210 BuiltinType::Kind ElementKind = BTy->getKind(); 2211 2212 switch(E->getOpcode()) { 2213 default: llvm_unreachable("is not a comparison operation"); 2214 case BO_EQ: 2215 CR6 = CR6_LT; 2216 ID = GetIntrinsic(VCMPEQ, ElementKind); 2217 break; 2218 case BO_NE: 2219 CR6 = CR6_EQ; 2220 ID = GetIntrinsic(VCMPEQ, ElementKind); 2221 break; 2222 case BO_LT: 2223 CR6 = CR6_LT; 2224 ID = GetIntrinsic(VCMPGT, ElementKind); 2225 std::swap(FirstVecArg, SecondVecArg); 2226 break; 2227 case BO_GT: 2228 CR6 = CR6_LT; 2229 ID = GetIntrinsic(VCMPGT, ElementKind); 2230 break; 2231 case BO_LE: 2232 if (ElementKind == BuiltinType::Float) { 2233 CR6 = CR6_LT; 2234 ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p; 2235 std::swap(FirstVecArg, SecondVecArg); 2236 } 2237 else { 2238 CR6 = CR6_EQ; 2239 ID = GetIntrinsic(VCMPGT, ElementKind); 2240 } 2241 break; 2242 case BO_GE: 2243 if (ElementKind == BuiltinType::Float) { 2244 CR6 = CR6_LT; 2245 ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p; 2246 } 2247 else { 2248 CR6 = CR6_EQ; 2249 ID = GetIntrinsic(VCMPGT, ElementKind); 2250 std::swap(FirstVecArg, SecondVecArg); 2251 } 2252 break; 2253 } 2254 2255 Value *CR6Param = Builder.getInt32(CR6); 2256 llvm::Function *F = CGF.CGM.getIntrinsic(ID); 2257 Result = Builder.CreateCall3(F, CR6Param, FirstVecArg, SecondVecArg, ""); 2258 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 2259 } 2260 2261 if (LHS->getType()->isFPOrFPVectorTy()) { 2262 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 2263 LHS, RHS, "cmp"); 2264 } else if (LHSTy->hasSignedIntegerRepresentation()) { 2265 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 2266 LHS, RHS, "cmp"); 2267 } else { 2268 // Unsigned integers and pointers. 2269 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2270 LHS, RHS, "cmp"); 2271 } 2272 2273 // If this is a vector comparison, sign extend the result to the appropriate 2274 // vector integer type and return it (don't convert to bool). 2275 if (LHSTy->isVectorType()) 2276 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 2277 2278 } else { 2279 // Complex Comparison: can only be an equality comparison. 2280 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 2281 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 2282 2283 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 2284 2285 Value *ResultR, *ResultI; 2286 if (CETy->isRealFloatingType()) { 2287 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 2288 LHS.first, RHS.first, "cmp.r"); 2289 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 2290 LHS.second, RHS.second, "cmp.i"); 2291 } else { 2292 // Complex comparisons can only be equality comparisons. As such, signed 2293 // and unsigned opcodes are the same. 2294 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2295 LHS.first, RHS.first, "cmp.r"); 2296 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2297 LHS.second, RHS.second, "cmp.i"); 2298 } 2299 2300 if (E->getOpcode() == BO_EQ) { 2301 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 2302 } else { 2303 assert(E->getOpcode() == BO_NE && 2304 "Complex comparison other than == or != ?"); 2305 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 2306 } 2307 } 2308 2309 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 2310 } 2311 2312 Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 2313 bool Ignore = TestAndClearIgnoreResultAssign(); 2314 2315 Value *RHS; 2316 LValue LHS; 2317 2318 switch (E->getLHS()->getType().getObjCLifetime()) { 2319 case Qualifiers::OCL_Strong: 2320 llvm::tie(LHS, RHS) = CGF.EmitARCStoreStrong(E, Ignore); 2321 break; 2322 2323 case Qualifiers::OCL_Autoreleasing: 2324 llvm::tie(LHS,RHS) = CGF.EmitARCStoreAutoreleasing(E); 2325 break; 2326 2327 case Qualifiers::OCL_Weak: 2328 RHS = Visit(E->getRHS()); 2329 LHS = EmitCheckedLValue(E->getLHS()); 2330 RHS = CGF.EmitARCStoreWeak(LHS.getAddress(), RHS, Ignore); 2331 break; 2332 2333 // No reason to do any of these differently. 2334 case Qualifiers::OCL_None: 2335 case Qualifiers::OCL_ExplicitNone: 2336 // __block variables need to have the rhs evaluated first, plus 2337 // this should improve codegen just a little. 2338 RHS = Visit(E->getRHS()); 2339 LHS = EmitCheckedLValue(E->getLHS()); 2340 2341 // Store the value into the LHS. Bit-fields are handled specially 2342 // because the result is altered by the store, i.e., [C99 6.5.16p1] 2343 // 'An assignment expression has the value of the left operand after 2344 // the assignment...'. 2345 if (LHS.isBitField()) 2346 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, &RHS); 2347 else 2348 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS); 2349 } 2350 2351 // If the result is clearly ignored, return now. 2352 if (Ignore) 2353 return 0; 2354 2355 // The result of an assignment in C is the assigned r-value. 2356 if (!CGF.getContext().getLangOpts().CPlusPlus) 2357 return RHS; 2358 2359 // If the lvalue is non-volatile, return the computed value of the assignment. 2360 if (!LHS.isVolatileQualified()) 2361 return RHS; 2362 2363 // Otherwise, reload the value. 2364 return EmitLoadOfLValue(LHS); 2365 } 2366 2367 Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 2368 2369 // Perform vector logical and on comparisons with zero vectors. 2370 if (E->getType()->isVectorType()) { 2371 Value *LHS = Visit(E->getLHS()); 2372 Value *RHS = Visit(E->getRHS()); 2373 Value *Zero = llvm::ConstantAggregateZero::get(LHS->getType()); 2374 LHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, LHS, Zero, "cmp"); 2375 RHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, RHS, Zero, "cmp"); 2376 Value *And = Builder.CreateAnd(LHS, RHS); 2377 return Builder.CreateSExt(And, Zero->getType(), "sext"); 2378 } 2379 2380 llvm::Type *ResTy = ConvertType(E->getType()); 2381 2382 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 2383 // If we have 1 && X, just emit X without inserting the control flow. 2384 bool LHSCondVal; 2385 if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) { 2386 if (LHSCondVal) { // If we have 1 && X, just emit X. 2387 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2388 // ZExt result to int or bool. 2389 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 2390 } 2391 2392 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 2393 if (!CGF.ContainsLabel(E->getRHS())) 2394 return llvm::Constant::getNullValue(ResTy); 2395 } 2396 2397 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 2398 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 2399 2400 CodeGenFunction::ConditionalEvaluation eval(CGF); 2401 2402 // Branch on the LHS first. If it is false, go to the failure (cont) block. 2403 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 2404 2405 // Any edges into the ContBlock are now from an (indeterminate number of) 2406 // edges from this first condition. All of these values will be false. Start 2407 // setting up the PHI node in the Cont Block for this. 2408 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2, 2409 "", ContBlock); 2410 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 2411 PI != PE; ++PI) 2412 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 2413 2414 eval.begin(CGF); 2415 CGF.EmitBlock(RHSBlock); 2416 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2417 eval.end(CGF); 2418 2419 // Reaquire the RHS block, as there may be subblocks inserted. 2420 RHSBlock = Builder.GetInsertBlock(); 2421 2422 // Emit an unconditional branch from this block to ContBlock. Insert an entry 2423 // into the phi node for the edge with the value of RHSCond. 2424 if (CGF.getDebugInfo()) 2425 // There is no need to emit line number for unconditional branch. 2426 Builder.SetCurrentDebugLocation(llvm::DebugLoc()); 2427 CGF.EmitBlock(ContBlock); 2428 PN->addIncoming(RHSCond, RHSBlock); 2429 2430 // ZExt result to int. 2431 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); 2432 } 2433 2434 Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 2435 2436 // Perform vector logical or on comparisons with zero vectors. 2437 if (E->getType()->isVectorType()) { 2438 Value *LHS = Visit(E->getLHS()); 2439 Value *RHS = Visit(E->getRHS()); 2440 Value *Zero = llvm::ConstantAggregateZero::get(LHS->getType()); 2441 LHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, LHS, Zero, "cmp"); 2442 RHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, RHS, Zero, "cmp"); 2443 Value *Or = Builder.CreateOr(LHS, RHS); 2444 return Builder.CreateSExt(Or, Zero->getType(), "sext"); 2445 } 2446 2447 llvm::Type *ResTy = ConvertType(E->getType()); 2448 2449 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 2450 // If we have 0 || X, just emit X without inserting the control flow. 2451 bool LHSCondVal; 2452 if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) { 2453 if (!LHSCondVal) { // If we have 0 || X, just emit X. 2454 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2455 // ZExt result to int or bool. 2456 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 2457 } 2458 2459 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 2460 if (!CGF.ContainsLabel(E->getRHS())) 2461 return llvm::ConstantInt::get(ResTy, 1); 2462 } 2463 2464 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 2465 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 2466 2467 CodeGenFunction::ConditionalEvaluation eval(CGF); 2468 2469 // Branch on the LHS first. If it is true, go to the success (cont) block. 2470 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 2471 2472 // Any edges into the ContBlock are now from an (indeterminate number of) 2473 // edges from this first condition. All of these values will be true. Start 2474 // setting up the PHI node in the Cont Block for this. 2475 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2, 2476 "", ContBlock); 2477 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 2478 PI != PE; ++PI) 2479 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 2480 2481 eval.begin(CGF); 2482 2483 // Emit the RHS condition as a bool value. 2484 CGF.EmitBlock(RHSBlock); 2485 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2486 2487 eval.end(CGF); 2488 2489 // Reaquire the RHS block, as there may be subblocks inserted. 2490 RHSBlock = Builder.GetInsertBlock(); 2491 2492 // Emit an unconditional branch from this block to ContBlock. Insert an entry 2493 // into the phi node for the edge with the value of RHSCond. 2494 CGF.EmitBlock(ContBlock); 2495 PN->addIncoming(RHSCond, RHSBlock); 2496 2497 // ZExt result to int. 2498 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 2499 } 2500 2501 Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 2502 CGF.EmitIgnoredExpr(E->getLHS()); 2503 CGF.EnsureInsertPoint(); 2504 return Visit(E->getRHS()); 2505 } 2506 2507 //===----------------------------------------------------------------------===// 2508 // Other Operators 2509 //===----------------------------------------------------------------------===// 2510 2511 /// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 2512 /// expression is cheap enough and side-effect-free enough to evaluate 2513 /// unconditionally instead of conditionally. This is used to convert control 2514 /// flow into selects in some cases. 2515 static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 2516 CodeGenFunction &CGF) { 2517 E = E->IgnoreParens(); 2518 2519 // Anything that is an integer or floating point constant is fine. 2520 if (E->isConstantInitializer(CGF.getContext(), false)) 2521 return true; 2522 2523 // Non-volatile automatic variables too, to get "cond ? X : Y" where 2524 // X and Y are local variables. 2525 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 2526 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 2527 if (VD->hasLocalStorage() && !(CGF.getContext() 2528 .getCanonicalType(VD->getType()) 2529 .isVolatileQualified())) 2530 return true; 2531 2532 return false; 2533 } 2534 2535 2536 Value *ScalarExprEmitter:: 2537 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) { 2538 TestAndClearIgnoreResultAssign(); 2539 2540 // Bind the common expression if necessary. 2541 CodeGenFunction::OpaqueValueMapping binding(CGF, E); 2542 2543 Expr *condExpr = E->getCond(); 2544 Expr *lhsExpr = E->getTrueExpr(); 2545 Expr *rhsExpr = E->getFalseExpr(); 2546 2547 // If the condition constant folds and can be elided, try to avoid emitting 2548 // the condition and the dead arm. 2549 bool CondExprBool; 2550 if (CGF.ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) { 2551 Expr *live = lhsExpr, *dead = rhsExpr; 2552 if (!CondExprBool) std::swap(live, dead); 2553 2554 // If the dead side doesn't have labels we need, just emit the Live part. 2555 if (!CGF.ContainsLabel(dead)) { 2556 Value *Result = Visit(live); 2557 2558 // If the live part is a throw expression, it acts like it has a void 2559 // type, so evaluating it returns a null Value*. However, a conditional 2560 // with non-void type must return a non-null Value*. 2561 if (!Result && !E->getType()->isVoidType()) 2562 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType())); 2563 2564 return Result; 2565 } 2566 } 2567 2568 // OpenCL: If the condition is a vector, we can treat this condition like 2569 // the select function. 2570 if (CGF.getContext().getLangOpts().OpenCL 2571 && condExpr->getType()->isVectorType()) { 2572 llvm::Value *CondV = CGF.EmitScalarExpr(condExpr); 2573 llvm::Value *LHS = Visit(lhsExpr); 2574 llvm::Value *RHS = Visit(rhsExpr); 2575 2576 llvm::Type *condType = ConvertType(condExpr->getType()); 2577 llvm::VectorType *vecTy = cast<llvm::VectorType>(condType); 2578 2579 unsigned numElem = vecTy->getNumElements(); 2580 llvm::Type *elemType = vecTy->getElementType(); 2581 2582 llvm::Value *zeroVec = llvm::Constant::getNullValue(vecTy); 2583 llvm::Value *TestMSB = Builder.CreateICmpSLT(CondV, zeroVec); 2584 llvm::Value *tmp = Builder.CreateSExt(TestMSB, 2585 llvm::VectorType::get(elemType, 2586 numElem), 2587 "sext"); 2588 llvm::Value *tmp2 = Builder.CreateNot(tmp); 2589 2590 // Cast float to int to perform ANDs if necessary. 2591 llvm::Value *RHSTmp = RHS; 2592 llvm::Value *LHSTmp = LHS; 2593 bool wasCast = false; 2594 llvm::VectorType *rhsVTy = cast<llvm::VectorType>(RHS->getType()); 2595 if (rhsVTy->getElementType()->isFloatTy()) { 2596 RHSTmp = Builder.CreateBitCast(RHS, tmp2->getType()); 2597 LHSTmp = Builder.CreateBitCast(LHS, tmp->getType()); 2598 wasCast = true; 2599 } 2600 2601 llvm::Value *tmp3 = Builder.CreateAnd(RHSTmp, tmp2); 2602 llvm::Value *tmp4 = Builder.CreateAnd(LHSTmp, tmp); 2603 llvm::Value *tmp5 = Builder.CreateOr(tmp3, tmp4, "cond"); 2604 if (wasCast) 2605 tmp5 = Builder.CreateBitCast(tmp5, RHS->getType()); 2606 2607 return tmp5; 2608 } 2609 2610 // If this is a really simple expression (like x ? 4 : 5), emit this as a 2611 // select instead of as control flow. We can only do this if it is cheap and 2612 // safe to evaluate the LHS and RHS unconditionally. 2613 if (isCheapEnoughToEvaluateUnconditionally(lhsExpr, CGF) && 2614 isCheapEnoughToEvaluateUnconditionally(rhsExpr, CGF)) { 2615 llvm::Value *CondV = CGF.EvaluateExprAsBool(condExpr); 2616 llvm::Value *LHS = Visit(lhsExpr); 2617 llvm::Value *RHS = Visit(rhsExpr); 2618 if (!LHS) { 2619 // If the conditional has void type, make sure we return a null Value*. 2620 assert(!RHS && "LHS and RHS types must match"); 2621 return 0; 2622 } 2623 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 2624 } 2625 2626 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 2627 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 2628 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 2629 2630 CodeGenFunction::ConditionalEvaluation eval(CGF); 2631 CGF.EmitBranchOnBoolExpr(condExpr, LHSBlock, RHSBlock); 2632 2633 CGF.EmitBlock(LHSBlock); 2634 eval.begin(CGF); 2635 Value *LHS = Visit(lhsExpr); 2636 eval.end(CGF); 2637 2638 LHSBlock = Builder.GetInsertBlock(); 2639 Builder.CreateBr(ContBlock); 2640 2641 CGF.EmitBlock(RHSBlock); 2642 eval.begin(CGF); 2643 Value *RHS = Visit(rhsExpr); 2644 eval.end(CGF); 2645 2646 RHSBlock = Builder.GetInsertBlock(); 2647 CGF.EmitBlock(ContBlock); 2648 2649 // If the LHS or RHS is a throw expression, it will be legitimately null. 2650 if (!LHS) 2651 return RHS; 2652 if (!RHS) 2653 return LHS; 2654 2655 // Create a PHI node for the real part. 2656 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), 2, "cond"); 2657 PN->addIncoming(LHS, LHSBlock); 2658 PN->addIncoming(RHS, RHSBlock); 2659 return PN; 2660 } 2661 2662 Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 2663 return Visit(E->getChosenSubExpr(CGF.getContext())); 2664 } 2665 2666 Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 2667 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 2668 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 2669 2670 // If EmitVAArg fails, we fall back to the LLVM instruction. 2671 if (!ArgPtr) 2672 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 2673 2674 // FIXME Volatility. 2675 return Builder.CreateLoad(ArgPtr); 2676 } 2677 2678 Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *block) { 2679 return CGF.EmitBlockLiteral(block); 2680 } 2681 2682 Value *ScalarExprEmitter::VisitAsTypeExpr(AsTypeExpr *E) { 2683 Value *Src = CGF.EmitScalarExpr(E->getSrcExpr()); 2684 llvm::Type *DstTy = ConvertType(E->getType()); 2685 2686 // Going from vec4->vec3 or vec3->vec4 is a special case and requires 2687 // a shuffle vector instead of a bitcast. 2688 llvm::Type *SrcTy = Src->getType(); 2689 if (isa<llvm::VectorType>(DstTy) && isa<llvm::VectorType>(SrcTy)) { 2690 unsigned numElementsDst = cast<llvm::VectorType>(DstTy)->getNumElements(); 2691 unsigned numElementsSrc = cast<llvm::VectorType>(SrcTy)->getNumElements(); 2692 if ((numElementsDst == 3 && numElementsSrc == 4) 2693 || (numElementsDst == 4 && numElementsSrc == 3)) { 2694 2695 2696 // In the case of going from int4->float3, a bitcast is needed before 2697 // doing a shuffle. 2698 llvm::Type *srcElemTy = 2699 cast<llvm::VectorType>(SrcTy)->getElementType(); 2700 llvm::Type *dstElemTy = 2701 cast<llvm::VectorType>(DstTy)->getElementType(); 2702 2703 if ((srcElemTy->isIntegerTy() && dstElemTy->isFloatTy()) 2704 || (srcElemTy->isFloatTy() && dstElemTy->isIntegerTy())) { 2705 // Create a float type of the same size as the source or destination. 2706 llvm::VectorType *newSrcTy = llvm::VectorType::get(dstElemTy, 2707 numElementsSrc); 2708 2709 Src = Builder.CreateBitCast(Src, newSrcTy, "astypeCast"); 2710 } 2711 2712 llvm::Value *UnV = llvm::UndefValue::get(Src->getType()); 2713 2714 SmallVector<llvm::Constant*, 3> Args; 2715 Args.push_back(Builder.getInt32(0)); 2716 Args.push_back(Builder.getInt32(1)); 2717 Args.push_back(Builder.getInt32(2)); 2718 2719 if (numElementsDst == 4) 2720 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 2721 2722 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 2723 2724 return Builder.CreateShuffleVector(Src, UnV, Mask, "astype"); 2725 } 2726 } 2727 2728 return Builder.CreateBitCast(Src, DstTy, "astype"); 2729 } 2730 2731 Value *ScalarExprEmitter::VisitAtomicExpr(AtomicExpr *E) { 2732 return CGF.EmitAtomicExpr(E).getScalarVal(); 2733 } 2734 2735 //===----------------------------------------------------------------------===// 2736 // Entry Point into this File 2737 //===----------------------------------------------------------------------===// 2738 2739 /// EmitScalarExpr - Emit the computation of the specified expression of scalar 2740 /// type, ignoring the result. 2741 Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 2742 assert(E && !hasAggregateLLVMType(E->getType()) && 2743 "Invalid scalar expression to emit"); 2744 2745 if (isa<CXXDefaultArgExpr>(E)) 2746 disableDebugInfo(); 2747 Value *V = ScalarExprEmitter(*this, IgnoreResultAssign) 2748 .Visit(const_cast<Expr*>(E)); 2749 if (isa<CXXDefaultArgExpr>(E)) 2750 enableDebugInfo(); 2751 return V; 2752 } 2753 2754 /// EmitScalarConversion - Emit a conversion from the specified type to the 2755 /// specified destination type, both of which are LLVM scalar types. 2756 Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 2757 QualType DstTy) { 2758 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 2759 "Invalid scalar expression to emit"); 2760 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 2761 } 2762 2763 /// EmitComplexToScalarConversion - Emit a conversion from the specified complex 2764 /// type to the specified destination type, where the destination type is an 2765 /// LLVM scalar type. 2766 Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 2767 QualType SrcTy, 2768 QualType DstTy) { 2769 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 2770 "Invalid complex -> scalar conversion"); 2771 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 2772 DstTy); 2773 } 2774 2775 2776 llvm::Value *CodeGenFunction:: 2777 EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 2778 bool isInc, bool isPre) { 2779 return ScalarExprEmitter(*this).EmitScalarPrePostIncDec(E, LV, isInc, isPre); 2780 } 2781 2782 LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) { 2783 llvm::Value *V; 2784 // object->isa or (*object).isa 2785 // Generate code as for: *(Class*)object 2786 // build Class* type 2787 llvm::Type *ClassPtrTy = ConvertType(E->getType()); 2788 2789 Expr *BaseExpr = E->getBase(); 2790 if (BaseExpr->isRValue()) { 2791 V = CreateMemTemp(E->getType(), "resval"); 2792 llvm::Value *Src = EmitScalarExpr(BaseExpr); 2793 Builder.CreateStore(Src, V); 2794 V = ScalarExprEmitter(*this).EmitLoadOfLValue( 2795 MakeNaturalAlignAddrLValue(V, E->getType())); 2796 } else { 2797 if (E->isArrow()) 2798 V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr); 2799 else 2800 V = EmitLValue(BaseExpr).getAddress(); 2801 } 2802 2803 // build Class* type 2804 ClassPtrTy = ClassPtrTy->getPointerTo(); 2805 V = Builder.CreateBitCast(V, ClassPtrTy); 2806 return MakeNaturalAlignAddrLValue(V, E->getType()); 2807 } 2808 2809 2810 LValue CodeGenFunction::EmitCompoundAssignmentLValue( 2811 const CompoundAssignOperator *E) { 2812 ScalarExprEmitter Scalar(*this); 2813 Value *Result = 0; 2814 switch (E->getOpcode()) { 2815 #define COMPOUND_OP(Op) \ 2816 case BO_##Op##Assign: \ 2817 return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \ 2818 Result) 2819 COMPOUND_OP(Mul); 2820 COMPOUND_OP(Div); 2821 COMPOUND_OP(Rem); 2822 COMPOUND_OP(Add); 2823 COMPOUND_OP(Sub); 2824 COMPOUND_OP(Shl); 2825 COMPOUND_OP(Shr); 2826 COMPOUND_OP(And); 2827 COMPOUND_OP(Xor); 2828 COMPOUND_OP(Or); 2829 #undef COMPOUND_OP 2830 2831 case BO_PtrMemD: 2832 case BO_PtrMemI: 2833 case BO_Mul: 2834 case BO_Div: 2835 case BO_Rem: 2836 case BO_Add: 2837 case BO_Sub: 2838 case BO_Shl: 2839 case BO_Shr: 2840 case BO_LT: 2841 case BO_GT: 2842 case BO_LE: 2843 case BO_GE: 2844 case BO_EQ: 2845 case BO_NE: 2846 case BO_And: 2847 case BO_Xor: 2848 case BO_Or: 2849 case BO_LAnd: 2850 case BO_LOr: 2851 case BO_Assign: 2852 case BO_Comma: 2853 llvm_unreachable("Not valid compound assignment operators"); 2854 } 2855 2856 llvm_unreachable("Unhandled compound assignment operator"); 2857 } 2858