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 *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 181 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 182 } 183 Value *VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) { 184 return EmitNullValue(E->getType()); 185 } 186 Value *VisitGNUNullExpr(const GNUNullExpr *E) { 187 return EmitNullValue(E->getType()); 188 } 189 Value *VisitOffsetOfExpr(OffsetOfExpr *E); 190 Value *VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E); 191 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 192 llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel()); 193 return Builder.CreateBitCast(V, ConvertType(E->getType())); 194 } 195 196 Value *VisitSizeOfPackExpr(SizeOfPackExpr *E) { 197 return llvm::ConstantInt::get(ConvertType(E->getType()),E->getPackLength()); 198 } 199 200 Value *VisitOpaqueValueExpr(OpaqueValueExpr *E) { 201 if (E->isGLValue()) 202 return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E)); 203 204 // Otherwise, assume the mapping is the scalar directly. 205 return CGF.getOpaqueRValueMapping(E).getScalarVal(); 206 } 207 208 // l-values. 209 Value *VisitDeclRefExpr(DeclRefExpr *E) { 210 Expr::EvalResult Result; 211 if (!E->Evaluate(Result, CGF.getContext())) 212 return EmitLoadOfLValue(E); 213 214 assert(!Result.HasSideEffects && "Constant declref with side-effect?!"); 215 216 llvm::Constant *C; 217 if (Result.Val.isInt()) 218 C = Builder.getInt(Result.Val.getInt()); 219 else if (Result.Val.isFloat()) 220 C = llvm::ConstantFP::get(VMContext, Result.Val.getFloat()); 221 else 222 return EmitLoadOfLValue(E); 223 224 // Make sure we emit a debug reference to the global variable. 225 if (VarDecl *VD = dyn_cast<VarDecl>(E->getDecl())) { 226 if (!CGF.getContext().DeclMustBeEmitted(VD)) 227 CGF.EmitDeclRefExprDbgValue(E, C); 228 } else if (isa<EnumConstantDecl>(E->getDecl())) { 229 CGF.EmitDeclRefExprDbgValue(E, C); 230 } 231 232 return C; 233 } 234 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 235 return CGF.EmitObjCSelectorExpr(E); 236 } 237 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 238 return CGF.EmitObjCProtocolExpr(E); 239 } 240 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 241 return EmitLoadOfLValue(E); 242 } 243 Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { 244 assert(E->getObjectKind() == OK_Ordinary && 245 "reached property reference without lvalue-to-rvalue"); 246 return EmitLoadOfLValue(E); 247 } 248 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 249 if (E->getMethodDecl() && 250 E->getMethodDecl()->getResultType()->isReferenceType()) 251 return EmitLoadOfLValue(E); 252 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 253 } 254 255 Value *VisitObjCIsaExpr(ObjCIsaExpr *E) { 256 LValue LV = CGF.EmitObjCIsaExpr(E); 257 Value *V = CGF.EmitLoadOfLValue(LV).getScalarVal(); 258 return V; 259 } 260 261 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 262 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 263 Value *VisitMemberExpr(MemberExpr *E); 264 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 265 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 266 return EmitLoadOfLValue(E); 267 } 268 269 Value *VisitInitListExpr(InitListExpr *E); 270 271 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { 272 return CGF.CGM.EmitNullConstant(E->getType()); 273 } 274 Value *VisitExplicitCastExpr(ExplicitCastExpr *E) { 275 if (E->getType()->isVariablyModifiedType()) 276 CGF.EmitVariablyModifiedType(E->getType()); 277 return VisitCastExpr(E); 278 } 279 Value *VisitCastExpr(CastExpr *E); 280 281 Value *VisitCallExpr(const CallExpr *E) { 282 if (E->getCallReturnType()->isReferenceType()) 283 return EmitLoadOfLValue(E); 284 285 return CGF.EmitCallExpr(E).getScalarVal(); 286 } 287 288 Value *VisitStmtExpr(const StmtExpr *E); 289 290 Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E); 291 292 // Unary Operators. 293 Value *VisitUnaryPostDec(const UnaryOperator *E) { 294 LValue LV = EmitLValue(E->getSubExpr()); 295 return EmitScalarPrePostIncDec(E, LV, false, false); 296 } 297 Value *VisitUnaryPostInc(const UnaryOperator *E) { 298 LValue LV = EmitLValue(E->getSubExpr()); 299 return EmitScalarPrePostIncDec(E, LV, true, false); 300 } 301 Value *VisitUnaryPreDec(const UnaryOperator *E) { 302 LValue LV = EmitLValue(E->getSubExpr()); 303 return EmitScalarPrePostIncDec(E, LV, false, true); 304 } 305 Value *VisitUnaryPreInc(const UnaryOperator *E) { 306 LValue LV = EmitLValue(E->getSubExpr()); 307 return EmitScalarPrePostIncDec(E, LV, true, true); 308 } 309 310 llvm::Value *EmitAddConsiderOverflowBehavior(const UnaryOperator *E, 311 llvm::Value *InVal, 312 llvm::Value *NextVal, 313 bool IsInc); 314 315 llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 316 bool isInc, bool isPre); 317 318 319 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 320 if (isa<MemberPointerType>(E->getType())) // never sugared 321 return CGF.CGM.getMemberPointerConstant(E); 322 323 return EmitLValue(E->getSubExpr()).getAddress(); 324 } 325 Value *VisitUnaryDeref(const UnaryOperator *E) { 326 if (E->getType()->isVoidType()) 327 return Visit(E->getSubExpr()); // the actual value should be unused 328 return EmitLoadOfLValue(E); 329 } 330 Value *VisitUnaryPlus(const UnaryOperator *E) { 331 // This differs from gcc, though, most likely due to a bug in gcc. 332 TestAndClearIgnoreResultAssign(); 333 return Visit(E->getSubExpr()); 334 } 335 Value *VisitUnaryMinus (const UnaryOperator *E); 336 Value *VisitUnaryNot (const UnaryOperator *E); 337 Value *VisitUnaryLNot (const UnaryOperator *E); 338 Value *VisitUnaryReal (const UnaryOperator *E); 339 Value *VisitUnaryImag (const UnaryOperator *E); 340 Value *VisitUnaryExtension(const UnaryOperator *E) { 341 return Visit(E->getSubExpr()); 342 } 343 344 // C++ 345 Value *VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E) { 346 return EmitLoadOfLValue(E); 347 } 348 349 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 350 return Visit(DAE->getExpr()); 351 } 352 Value *VisitCXXThisExpr(CXXThisExpr *TE) { 353 return CGF.LoadCXXThis(); 354 } 355 356 Value *VisitExprWithCleanups(ExprWithCleanups *E) { 357 return CGF.EmitExprWithCleanups(E).getScalarVal(); 358 } 359 Value *VisitCXXNewExpr(const CXXNewExpr *E) { 360 return CGF.EmitCXXNewExpr(E); 361 } 362 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { 363 CGF.EmitCXXDeleteExpr(E); 364 return 0; 365 } 366 Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) { 367 return Builder.getInt1(E->getValue()); 368 } 369 370 Value *VisitBinaryTypeTraitExpr(const BinaryTypeTraitExpr *E) { 371 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 372 } 373 374 Value *VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) { 375 return llvm::ConstantInt::get(Builder.getInt32Ty(), E->getValue()); 376 } 377 378 Value *VisitExpressionTraitExpr(const ExpressionTraitExpr *E) { 379 return llvm::ConstantInt::get(Builder.getInt1Ty(), E->getValue()); 380 } 381 382 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { 383 // C++ [expr.pseudo]p1: 384 // The result shall only be used as the operand for the function call 385 // operator (), and the result of such a call has type void. The only 386 // effect is the evaluation of the postfix-expression before the dot or 387 // arrow. 388 CGF.EmitScalarExpr(E->getBase()); 389 return 0; 390 } 391 392 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { 393 return EmitNullValue(E->getType()); 394 } 395 396 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { 397 CGF.EmitCXXThrowExpr(E); 398 return 0; 399 } 400 401 Value *VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) { 402 return Builder.getInt1(E->getValue()); 403 } 404 405 // Binary Operators. 406 Value *EmitMul(const BinOpInfo &Ops) { 407 if (Ops.Ty->isSignedIntegerOrEnumerationType()) { 408 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 409 case LangOptions::SOB_Undefined: 410 return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul"); 411 case LangOptions::SOB_Defined: 412 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 413 case LangOptions::SOB_Trapping: 414 return EmitOverflowCheckedBinOp(Ops); 415 } 416 } 417 418 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 419 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 420 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 421 } 422 bool isTrapvOverflowBehavior() { 423 return CGF.getContext().getLangOptions().getSignedOverflowBehavior() 424 == LangOptions::SOB_Trapping; 425 } 426 /// Create a binary op that checks for overflow. 427 /// Currently only supports +, - and *. 428 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 429 // Emit the overflow BB when -ftrapv option is activated. 430 void EmitOverflowBB(llvm::BasicBlock *overflowBB) { 431 Builder.SetInsertPoint(overflowBB); 432 llvm::Function *Trap = CGF.CGM.getIntrinsic(llvm::Intrinsic::trap); 433 Builder.CreateCall(Trap); 434 Builder.CreateUnreachable(); 435 } 436 // Check for undefined division and modulus behaviors. 437 void EmitUndefinedBehaviorIntegerDivAndRemCheck(const BinOpInfo &Ops, 438 llvm::Value *Zero,bool isDiv); 439 Value *EmitDiv(const BinOpInfo &Ops); 440 Value *EmitRem(const BinOpInfo &Ops); 441 Value *EmitAdd(const BinOpInfo &Ops); 442 Value *EmitSub(const BinOpInfo &Ops); 443 Value *EmitShl(const BinOpInfo &Ops); 444 Value *EmitShr(const BinOpInfo &Ops); 445 Value *EmitAnd(const BinOpInfo &Ops) { 446 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 447 } 448 Value *EmitXor(const BinOpInfo &Ops) { 449 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 450 } 451 Value *EmitOr (const BinOpInfo &Ops) { 452 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 453 } 454 455 BinOpInfo EmitBinOps(const BinaryOperator *E); 456 LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E, 457 Value *(ScalarExprEmitter::*F)(const BinOpInfo &), 458 Value *&Result); 459 460 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 461 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 462 463 // Binary operators and binary compound assignment operators. 464 #define HANDLEBINOP(OP) \ 465 Value *VisitBin ## OP(const BinaryOperator *E) { \ 466 return Emit ## OP(EmitBinOps(E)); \ 467 } \ 468 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 469 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 470 } 471 HANDLEBINOP(Mul) 472 HANDLEBINOP(Div) 473 HANDLEBINOP(Rem) 474 HANDLEBINOP(Add) 475 HANDLEBINOP(Sub) 476 HANDLEBINOP(Shl) 477 HANDLEBINOP(Shr) 478 HANDLEBINOP(And) 479 HANDLEBINOP(Xor) 480 HANDLEBINOP(Or) 481 #undef HANDLEBINOP 482 483 // Comparisons. 484 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 485 unsigned SICmpOpc, unsigned FCmpOpc); 486 #define VISITCOMP(CODE, UI, SI, FP) \ 487 Value *VisitBin##CODE(const BinaryOperator *E) { \ 488 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 489 llvm::FCmpInst::FP); } 490 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT) 491 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT) 492 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE) 493 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE) 494 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ) 495 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE) 496 #undef VISITCOMP 497 498 Value *VisitBinAssign (const BinaryOperator *E); 499 500 Value *VisitBinLAnd (const BinaryOperator *E); 501 Value *VisitBinLOr (const BinaryOperator *E); 502 Value *VisitBinComma (const BinaryOperator *E); 503 504 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } 505 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); } 506 507 // Other Operators. 508 Value *VisitBlockExpr(const BlockExpr *BE); 509 Value *VisitAbstractConditionalOperator(const AbstractConditionalOperator *); 510 Value *VisitChooseExpr(ChooseExpr *CE); 511 Value *VisitVAArgExpr(VAArgExpr *VE); 512 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 513 return CGF.EmitObjCStringLiteral(E); 514 } 515 Value *VisitAsTypeExpr(AsTypeExpr *CE); 516 Value *VisitAtomicExpr(AtomicExpr *AE); 517 }; 518 } // end anonymous namespace. 519 520 //===----------------------------------------------------------------------===// 521 // Utilities 522 //===----------------------------------------------------------------------===// 523 524 /// EmitConversionToBool - Convert the specified expression value to a 525 /// boolean (i1) truth value. This is equivalent to "Val != 0". 526 Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 527 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs"); 528 529 if (SrcType->isRealFloatingType()) 530 return EmitFloatToBoolConversion(Src); 531 532 if (const MemberPointerType *MPT = dyn_cast<MemberPointerType>(SrcType)) 533 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, Src, MPT); 534 535 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 536 "Unknown scalar type to convert"); 537 538 if (isa<llvm::IntegerType>(Src->getType())) 539 return EmitIntToBoolConversion(Src); 540 541 assert(isa<llvm::PointerType>(Src->getType())); 542 return EmitPointerToBoolConversion(Src); 543 } 544 545 /// EmitScalarConversion - Emit a conversion from the specified type to the 546 /// specified destination type, both of which are LLVM scalar types. 547 Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 548 QualType DstType) { 549 SrcType = CGF.getContext().getCanonicalType(SrcType); 550 DstType = CGF.getContext().getCanonicalType(DstType); 551 if (SrcType == DstType) return Src; 552 553 if (DstType->isVoidType()) return 0; 554 555 llvm::Type *SrcTy = Src->getType(); 556 557 // Floating casts might be a bit special: if we're doing casts to / from half 558 // FP, we should go via special intrinsics. 559 if (SrcType->isHalfType()) { 560 Src = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16), Src); 561 SrcType = CGF.getContext().FloatTy; 562 SrcTy = llvm::Type::getFloatTy(VMContext); 563 } 564 565 // Handle conversions to bool first, they are special: comparisons against 0. 566 if (DstType->isBooleanType()) 567 return EmitConversionToBool(Src, SrcType); 568 569 llvm::Type *DstTy = ConvertType(DstType); 570 571 // Ignore conversions like int -> uint. 572 if (SrcTy == DstTy) 573 return Src; 574 575 // Handle pointer conversions next: pointers can only be converted to/from 576 // other pointers and integers. Check for pointer types in terms of LLVM, as 577 // some native types (like Obj-C id) may map to a pointer type. 578 if (isa<llvm::PointerType>(DstTy)) { 579 // The source value may be an integer, or a pointer. 580 if (isa<llvm::PointerType>(SrcTy)) 581 return Builder.CreateBitCast(Src, DstTy, "conv"); 582 583 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 584 // First, convert to the correct width so that we control the kind of 585 // extension. 586 llvm::Type *MiddleTy = CGF.IntPtrTy; 587 bool InputSigned = SrcType->isSignedIntegerOrEnumerationType(); 588 llvm::Value* IntResult = 589 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 590 // Then, cast to pointer. 591 return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); 592 } 593 594 if (isa<llvm::PointerType>(SrcTy)) { 595 // Must be an ptr to int cast. 596 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 597 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 598 } 599 600 // A scalar can be splatted to an extended vector of the same element type 601 if (DstType->isExtVectorType() && !SrcType->isVectorType()) { 602 // Cast the scalar to element type 603 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType(); 604 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 605 606 // Insert the element in element zero of an undef vector 607 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 608 llvm::Value *Idx = Builder.getInt32(0); 609 UnV = Builder.CreateInsertElement(UnV, Elt, Idx); 610 611 // Splat the element across to all elements 612 SmallVector<llvm::Constant*, 16> Args; 613 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 614 for (unsigned i = 0; i != NumElements; ++i) 615 Args.push_back(Builder.getInt32(0)); 616 617 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 618 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 619 return Yay; 620 } 621 622 // Allow bitcast from vector to integer/fp of the same size. 623 if (isa<llvm::VectorType>(SrcTy) || 624 isa<llvm::VectorType>(DstTy)) 625 return Builder.CreateBitCast(Src, DstTy, "conv"); 626 627 // Finally, we have the arithmetic types: real int/float. 628 Value *Res = NULL; 629 llvm::Type *ResTy = DstTy; 630 631 // Cast to half via float 632 if (DstType->isHalfType()) 633 DstTy = llvm::Type::getFloatTy(VMContext); 634 635 if (isa<llvm::IntegerType>(SrcTy)) { 636 bool InputSigned = SrcType->isSignedIntegerOrEnumerationType(); 637 if (isa<llvm::IntegerType>(DstTy)) 638 Res = Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 639 else if (InputSigned) 640 Res = Builder.CreateSIToFP(Src, DstTy, "conv"); 641 else 642 Res = Builder.CreateUIToFP(Src, DstTy, "conv"); 643 } else if (isa<llvm::IntegerType>(DstTy)) { 644 assert(SrcTy->isFloatingPointTy() && "Unknown real conversion"); 645 if (DstType->isSignedIntegerOrEnumerationType()) 646 Res = Builder.CreateFPToSI(Src, DstTy, "conv"); 647 else 648 Res = Builder.CreateFPToUI(Src, DstTy, "conv"); 649 } else { 650 assert(SrcTy->isFloatingPointTy() && DstTy->isFloatingPointTy() && 651 "Unknown real conversion"); 652 if (DstTy->getTypeID() < SrcTy->getTypeID()) 653 Res = Builder.CreateFPTrunc(Src, DstTy, "conv"); 654 else 655 Res = Builder.CreateFPExt(Src, DstTy, "conv"); 656 } 657 658 if (DstTy != ResTy) { 659 assert(ResTy->isIntegerTy(16) && "Only half FP requires extra conversion"); 660 Res = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16), Res); 661 } 662 663 return Res; 664 } 665 666 /// EmitComplexToScalarConversion - Emit a conversion from the specified complex 667 /// type to the specified destination type, where the destination type is an 668 /// LLVM scalar type. 669 Value *ScalarExprEmitter:: 670 EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 671 QualType SrcTy, QualType DstTy) { 672 // Get the source element type. 673 SrcTy = SrcTy->getAs<ComplexType>()->getElementType(); 674 675 // Handle conversions to bool first, they are special: comparisons against 0. 676 if (DstTy->isBooleanType()) { 677 // Complex != 0 -> (Real != 0) | (Imag != 0) 678 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 679 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 680 return Builder.CreateOr(Src.first, Src.second, "tobool"); 681 } 682 683 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 684 // the imaginary part of the complex value is discarded and the value of the 685 // real part is converted according to the conversion rules for the 686 // corresponding real type. 687 return EmitScalarConversion(Src.first, SrcTy, DstTy); 688 } 689 690 Value *ScalarExprEmitter::EmitNullValue(QualType Ty) { 691 if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>()) 692 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 693 694 return llvm::Constant::getNullValue(ConvertType(Ty)); 695 } 696 697 //===----------------------------------------------------------------------===// 698 // Visitor Methods 699 //===----------------------------------------------------------------------===// 700 701 Value *ScalarExprEmitter::VisitExpr(Expr *E) { 702 CGF.ErrorUnsupported(E, "scalar expression"); 703 if (E->getType()->isVoidType()) 704 return 0; 705 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 706 } 707 708 Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 709 // Vector Mask Case 710 if (E->getNumSubExprs() == 2 || 711 (E->getNumSubExprs() == 3 && E->getExpr(2)->getType()->isVectorType())) { 712 Value *LHS = CGF.EmitScalarExpr(E->getExpr(0)); 713 Value *RHS = CGF.EmitScalarExpr(E->getExpr(1)); 714 Value *Mask; 715 716 llvm::VectorType *LTy = cast<llvm::VectorType>(LHS->getType()); 717 unsigned LHSElts = LTy->getNumElements(); 718 719 if (E->getNumSubExprs() == 3) { 720 Mask = CGF.EmitScalarExpr(E->getExpr(2)); 721 722 // Shuffle LHS & RHS into one input vector. 723 SmallVector<llvm::Constant*, 32> concat; 724 for (unsigned i = 0; i != LHSElts; ++i) { 725 concat.push_back(Builder.getInt32(2*i)); 726 concat.push_back(Builder.getInt32(2*i+1)); 727 } 728 729 Value* CV = llvm::ConstantVector::get(concat); 730 LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat"); 731 LHSElts *= 2; 732 } else { 733 Mask = RHS; 734 } 735 736 llvm::VectorType *MTy = cast<llvm::VectorType>(Mask->getType()); 737 llvm::Constant* EltMask; 738 739 // Treat vec3 like vec4. 740 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) 741 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 742 (1 << llvm::Log2_32(LHSElts+2))-1); 743 else if ((LHSElts == 3) && (E->getNumSubExprs() == 2)) 744 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 745 (1 << llvm::Log2_32(LHSElts+1))-1); 746 else 747 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 748 (1 << llvm::Log2_32(LHSElts))-1); 749 750 // Mask off the high bits of each shuffle index. 751 SmallVector<llvm::Constant *, 32> MaskV; 752 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) 753 MaskV.push_back(EltMask); 754 755 Value* MaskBits = llvm::ConstantVector::get(MaskV); 756 Mask = Builder.CreateAnd(Mask, MaskBits, "mask"); 757 758 // newv = undef 759 // mask = mask & maskbits 760 // for each elt 761 // n = extract mask i 762 // x = extract val n 763 // newv = insert newv, x, i 764 llvm::VectorType *RTy = llvm::VectorType::get(LTy->getElementType(), 765 MTy->getNumElements()); 766 Value* NewV = llvm::UndefValue::get(RTy); 767 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) { 768 Value *Indx = Builder.getInt32(i); 769 Indx = Builder.CreateExtractElement(Mask, Indx, "shuf_idx"); 770 Indx = Builder.CreateZExt(Indx, CGF.Int32Ty, "idx_zext"); 771 772 // Handle vec3 special since the index will be off by one for the RHS. 773 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) { 774 Value *cmpIndx, *newIndx; 775 cmpIndx = Builder.CreateICmpUGT(Indx, Builder.getInt32(3), 776 "cmp_shuf_idx"); 777 newIndx = Builder.CreateSub(Indx, Builder.getInt32(1), "shuf_idx_adj"); 778 Indx = Builder.CreateSelect(cmpIndx, newIndx, Indx, "sel_shuf_idx"); 779 } 780 Value *VExt = Builder.CreateExtractElement(LHS, Indx, "shuf_elt"); 781 NewV = Builder.CreateInsertElement(NewV, VExt, Indx, "shuf_ins"); 782 } 783 return NewV; 784 } 785 786 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 787 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 788 789 // Handle vec3 special since the index will be off by one for the RHS. 790 llvm::VectorType *VTy = cast<llvm::VectorType>(V1->getType()); 791 SmallVector<llvm::Constant*, 32> indices; 792 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 793 unsigned Idx = E->getShuffleMaskIdx(CGF.getContext(), i-2); 794 if (VTy->getNumElements() == 3 && Idx > 3) 795 Idx -= 1; 796 indices.push_back(Builder.getInt32(Idx)); 797 } 798 799 Value *SV = llvm::ConstantVector::get(indices); 800 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 801 } 802 Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { 803 Expr::EvalResult Result; 804 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 805 if (E->isArrow()) 806 CGF.EmitScalarExpr(E->getBase()); 807 else 808 EmitLValue(E->getBase()); 809 return Builder.getInt(Result.Val.getInt()); 810 } 811 812 // Emit debug info for aggregate now, if it was delayed to reduce 813 // debug info size. 814 CGDebugInfo *DI = CGF.getDebugInfo(); 815 if (DI && CGF.CGM.getCodeGenOpts().LimitDebugInfo) { 816 QualType PQTy = E->getBase()->IgnoreParenImpCasts()->getType(); 817 if (const PointerType * PTy = dyn_cast<PointerType>(PQTy)) 818 if (FieldDecl *M = dyn_cast<FieldDecl>(E->getMemberDecl())) 819 DI->getOrCreateRecordType(PTy->getPointeeType(), 820 M->getParent()->getLocation()); 821 } 822 return EmitLoadOfLValue(E); 823 } 824 825 Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 826 TestAndClearIgnoreResultAssign(); 827 828 // Emit subscript expressions in rvalue context's. For most cases, this just 829 // loads the lvalue formed by the subscript expr. However, we have to be 830 // careful, because the base of a vector subscript is occasionally an rvalue, 831 // so we can't get it as an lvalue. 832 if (!E->getBase()->getType()->isVectorType()) 833 return EmitLoadOfLValue(E); 834 835 // Handle the vector case. The base must be a vector, the index must be an 836 // integer value. 837 Value *Base = Visit(E->getBase()); 838 Value *Idx = Visit(E->getIdx()); 839 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerOrEnumerationType(); 840 Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vecidxcast"); 841 return Builder.CreateExtractElement(Base, Idx, "vecext"); 842 } 843 844 static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, 845 unsigned Off, llvm::Type *I32Ty) { 846 int MV = SVI->getMaskValue(Idx); 847 if (MV == -1) 848 return llvm::UndefValue::get(I32Ty); 849 return llvm::ConstantInt::get(I32Ty, Off+MV); 850 } 851 852 Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) { 853 bool Ignore = TestAndClearIgnoreResultAssign(); 854 (void)Ignore; 855 assert (Ignore == false && "init list ignored"); 856 unsigned NumInitElements = E->getNumInits(); 857 858 if (E->hadArrayRangeDesignator()) 859 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 860 861 llvm::VectorType *VType = 862 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 863 864 if (!VType) { 865 if (NumInitElements == 0) { 866 // C++11 value-initialization for the scalar. 867 return EmitNullValue(E->getType()); 868 } 869 // We have a scalar in braces. Just use the first element. 870 return Visit(E->getInit(0)); 871 } 872 873 unsigned ResElts = VType->getNumElements(); 874 875 // Loop over initializers collecting the Value for each, and remembering 876 // whether the source was swizzle (ExtVectorElementExpr). This will allow 877 // us to fold the shuffle for the swizzle into the shuffle for the vector 878 // initializer, since LLVM optimizers generally do not want to touch 879 // shuffles. 880 unsigned CurIdx = 0; 881 bool VIsUndefShuffle = false; 882 llvm::Value *V = llvm::UndefValue::get(VType); 883 for (unsigned i = 0; i != NumInitElements; ++i) { 884 Expr *IE = E->getInit(i); 885 Value *Init = Visit(IE); 886 SmallVector<llvm::Constant*, 16> Args; 887 888 llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType()); 889 890 // Handle scalar elements. If the scalar initializer is actually one 891 // element of a different vector of the same width, use shuffle instead of 892 // extract+insert. 893 if (!VVT) { 894 if (isa<ExtVectorElementExpr>(IE)) { 895 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init); 896 897 if (EI->getVectorOperandType()->getNumElements() == ResElts) { 898 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand()); 899 Value *LHS = 0, *RHS = 0; 900 if (CurIdx == 0) { 901 // insert into undef -> shuffle (src, undef) 902 Args.push_back(C); 903 for (unsigned j = 1; j != ResElts; ++j) 904 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 905 906 LHS = EI->getVectorOperand(); 907 RHS = V; 908 VIsUndefShuffle = true; 909 } else if (VIsUndefShuffle) { 910 // insert into undefshuffle && size match -> shuffle (v, src) 911 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V); 912 for (unsigned j = 0; j != CurIdx; ++j) 913 Args.push_back(getMaskElt(SVV, j, 0, CGF.Int32Ty)); 914 Args.push_back(Builder.getInt32(ResElts + C->getZExtValue())); 915 for (unsigned j = CurIdx + 1; j != ResElts; ++j) 916 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 917 918 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 919 RHS = EI->getVectorOperand(); 920 VIsUndefShuffle = false; 921 } 922 if (!Args.empty()) { 923 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 924 V = Builder.CreateShuffleVector(LHS, RHS, Mask); 925 ++CurIdx; 926 continue; 927 } 928 } 929 } 930 V = Builder.CreateInsertElement(V, Init, Builder.getInt32(CurIdx), 931 "vecinit"); 932 VIsUndefShuffle = false; 933 ++CurIdx; 934 continue; 935 } 936 937 unsigned InitElts = VVT->getNumElements(); 938 939 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's 940 // input is the same width as the vector being constructed, generate an 941 // optimized shuffle of the swizzle input into the result. 942 unsigned Offset = (CurIdx == 0) ? 0 : ResElts; 943 if (isa<ExtVectorElementExpr>(IE)) { 944 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init); 945 Value *SVOp = SVI->getOperand(0); 946 llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType()); 947 948 if (OpTy->getNumElements() == ResElts) { 949 for (unsigned j = 0; j != CurIdx; ++j) { 950 // If the current vector initializer is a shuffle with undef, merge 951 // this shuffle directly into it. 952 if (VIsUndefShuffle) { 953 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0, 954 CGF.Int32Ty)); 955 } else { 956 Args.push_back(Builder.getInt32(j)); 957 } 958 } 959 for (unsigned j = 0, je = InitElts; j != je; ++j) 960 Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty)); 961 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 962 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 963 964 if (VIsUndefShuffle) 965 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 966 967 Init = SVOp; 968 } 969 } 970 971 // Extend init to result vector length, and then shuffle its contribution 972 // to the vector initializer into V. 973 if (Args.empty()) { 974 for (unsigned j = 0; j != InitElts; ++j) 975 Args.push_back(Builder.getInt32(j)); 976 for (unsigned j = InitElts; j != ResElts; ++j) 977 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 978 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 979 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), 980 Mask, "vext"); 981 982 Args.clear(); 983 for (unsigned j = 0; j != CurIdx; ++j) 984 Args.push_back(Builder.getInt32(j)); 985 for (unsigned j = 0; j != InitElts; ++j) 986 Args.push_back(Builder.getInt32(j+Offset)); 987 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 988 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 989 } 990 991 // If V is undef, make sure it ends up on the RHS of the shuffle to aid 992 // merging subsequent shuffles into this one. 993 if (CurIdx == 0) 994 std::swap(V, Init); 995 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 996 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); 997 VIsUndefShuffle = isa<llvm::UndefValue>(Init); 998 CurIdx += InitElts; 999 } 1000 1001 // FIXME: evaluate codegen vs. shuffling against constant null vector. 1002 // Emit remaining default initializers. 1003 llvm::Type *EltTy = VType->getElementType(); 1004 1005 // Emit remaining default initializers 1006 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { 1007 Value *Idx = Builder.getInt32(CurIdx); 1008 llvm::Value *Init = llvm::Constant::getNullValue(EltTy); 1009 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 1010 } 1011 return V; 1012 } 1013 1014 static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { 1015 const Expr *E = CE->getSubExpr(); 1016 1017 if (CE->getCastKind() == CK_UncheckedDerivedToBase) 1018 return false; 1019 1020 if (isa<CXXThisExpr>(E)) { 1021 // We always assume that 'this' is never null. 1022 return false; 1023 } 1024 1025 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { 1026 // And that glvalue casts are never null. 1027 if (ICE->getValueKind() != VK_RValue) 1028 return false; 1029 } 1030 1031 return true; 1032 } 1033 1034 // VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 1035 // have to handle a more broad range of conversions than explicit casts, as they 1036 // handle things like function to ptr-to-function decay etc. 1037 Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) { 1038 Expr *E = CE->getSubExpr(); 1039 QualType DestTy = CE->getType(); 1040 CastKind Kind = CE->getCastKind(); 1041 1042 if (!DestTy->isVoidType()) 1043 TestAndClearIgnoreResultAssign(); 1044 1045 // Since almost all cast kinds apply to scalars, this switch doesn't have 1046 // a default case, so the compiler will warn on a missing case. The cases 1047 // are in the same order as in the CastKind enum. 1048 switch (Kind) { 1049 case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!"); 1050 1051 case CK_LValueBitCast: 1052 case CK_ObjCObjectLValueCast: { 1053 Value *V = EmitLValue(E).getAddress(); 1054 V = Builder.CreateBitCast(V, 1055 ConvertType(CGF.getContext().getPointerType(DestTy))); 1056 return EmitLoadOfLValue(CGF.MakeAddrLValue(V, DestTy)); 1057 } 1058 1059 case CK_CPointerToObjCPointerCast: 1060 case CK_BlockPointerToObjCPointerCast: 1061 case CK_AnyPointerToBlockPointerCast: 1062 case CK_BitCast: { 1063 Value *Src = Visit(const_cast<Expr*>(E)); 1064 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 1065 } 1066 case CK_NoOp: 1067 case CK_UserDefinedConversion: 1068 return Visit(const_cast<Expr*>(E)); 1069 1070 case CK_BaseToDerived: { 1071 const CXXRecordDecl *DerivedClassDecl = 1072 DestTy->getCXXRecordDeclForPointerType(); 1073 1074 return CGF.GetAddressOfDerivedClass(Visit(E), DerivedClassDecl, 1075 CE->path_begin(), CE->path_end(), 1076 ShouldNullCheckClassCastValue(CE)); 1077 } 1078 case CK_UncheckedDerivedToBase: 1079 case CK_DerivedToBase: { 1080 const RecordType *DerivedClassTy = 1081 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 1082 CXXRecordDecl *DerivedClassDecl = 1083 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 1084 1085 return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl, 1086 CE->path_begin(), CE->path_end(), 1087 ShouldNullCheckClassCastValue(CE)); 1088 } 1089 case CK_Dynamic: { 1090 Value *V = Visit(const_cast<Expr*>(E)); 1091 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 1092 return CGF.EmitDynamicCast(V, DCE); 1093 } 1094 1095 case CK_ArrayToPointerDecay: { 1096 assert(E->getType()->isArrayType() && 1097 "Array to pointer decay must have array source type!"); 1098 1099 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 1100 1101 // Note that VLA pointers are always decayed, so we don't need to do 1102 // anything here. 1103 if (!E->getType()->isVariableArrayType()) { 1104 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 1105 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 1106 ->getElementType()) && 1107 "Expected pointer to array"); 1108 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 1109 } 1110 1111 // Make sure the array decay ends up being the right type. This matters if 1112 // the array type was of an incomplete type. 1113 return CGF.Builder.CreateBitCast(V, ConvertType(CE->getType())); 1114 } 1115 case CK_FunctionToPointerDecay: 1116 return EmitLValue(E).getAddress(); 1117 1118 case CK_NullToPointer: 1119 if (MustVisitNullValue(E)) 1120 (void) Visit(E); 1121 1122 return llvm::ConstantPointerNull::get( 1123 cast<llvm::PointerType>(ConvertType(DestTy))); 1124 1125 case CK_NullToMemberPointer: { 1126 if (MustVisitNullValue(E)) 1127 (void) Visit(E); 1128 1129 const MemberPointerType *MPT = CE->getType()->getAs<MemberPointerType>(); 1130 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 1131 } 1132 1133 case CK_BaseToDerivedMemberPointer: 1134 case CK_DerivedToBaseMemberPointer: { 1135 Value *Src = Visit(E); 1136 1137 // Note that the AST doesn't distinguish between checked and 1138 // unchecked member pointer conversions, so we always have to 1139 // implement checked conversions here. This is inefficient when 1140 // actual control flow may be required in order to perform the 1141 // check, which it is for data member pointers (but not member 1142 // function pointers on Itanium and ARM). 1143 return CGF.CGM.getCXXABI().EmitMemberPointerConversion(CGF, CE, Src); 1144 } 1145 1146 case CK_ARCProduceObject: 1147 return CGF.EmitARCRetainScalarExpr(E); 1148 case CK_ARCConsumeObject: 1149 return CGF.EmitObjCConsumeObject(E->getType(), Visit(E)); 1150 case CK_ARCReclaimReturnedObject: { 1151 llvm::Value *value = Visit(E); 1152 value = CGF.EmitARCRetainAutoreleasedReturnValue(value); 1153 return CGF.EmitObjCConsumeObject(E->getType(), value); 1154 } 1155 case CK_ARCExtendBlockObject: 1156 return CGF.EmitARCExtendBlockObject(E); 1157 1158 case CK_FloatingRealToComplex: 1159 case CK_FloatingComplexCast: 1160 case CK_IntegralRealToComplex: 1161 case CK_IntegralComplexCast: 1162 case CK_IntegralComplexToFloatingComplex: 1163 case CK_FloatingComplexToIntegralComplex: 1164 case CK_ConstructorConversion: 1165 case CK_ToUnion: 1166 llvm_unreachable("scalar cast to non-scalar value"); 1167 break; 1168 1169 case CK_GetObjCProperty: { 1170 assert(CGF.getContext().hasSameUnqualifiedType(E->getType(), DestTy)); 1171 assert(E->isGLValue() && E->getObjectKind() == OK_ObjCProperty && 1172 "CK_GetObjCProperty for non-lvalue or non-ObjCProperty"); 1173 RValue RV = CGF.EmitLoadOfLValue(CGF.EmitLValue(E)); 1174 return RV.getScalarVal(); 1175 } 1176 1177 case CK_LValueToRValue: 1178 assert(CGF.getContext().hasSameUnqualifiedType(E->getType(), DestTy)); 1179 assert(E->isGLValue() && "lvalue-to-rvalue applied to r-value!"); 1180 return Visit(const_cast<Expr*>(E)); 1181 1182 case CK_IntegralToPointer: { 1183 Value *Src = Visit(const_cast<Expr*>(E)); 1184 1185 // First, convert to the correct width so that we control the kind of 1186 // extension. 1187 llvm::Type *MiddleTy = CGF.IntPtrTy; 1188 bool InputSigned = E->getType()->isSignedIntegerOrEnumerationType(); 1189 llvm::Value* IntResult = 1190 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 1191 1192 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 1193 } 1194 case CK_PointerToIntegral: 1195 assert(!DestTy->isBooleanType() && "bool should use PointerToBool"); 1196 return Builder.CreatePtrToInt(Visit(E), ConvertType(DestTy)); 1197 1198 case CK_ToVoid: { 1199 CGF.EmitIgnoredExpr(E); 1200 return 0; 1201 } 1202 case CK_VectorSplat: { 1203 llvm::Type *DstTy = ConvertType(DestTy); 1204 Value *Elt = Visit(const_cast<Expr*>(E)); 1205 1206 // Insert the element in element zero of an undef vector 1207 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 1208 llvm::Value *Idx = Builder.getInt32(0); 1209 UnV = Builder.CreateInsertElement(UnV, Elt, Idx); 1210 1211 // Splat the element across to all elements 1212 SmallVector<llvm::Constant*, 16> Args; 1213 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 1214 llvm::Constant *Zero = Builder.getInt32(0); 1215 for (unsigned i = 0; i < NumElements; i++) 1216 Args.push_back(Zero); 1217 1218 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 1219 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 1220 return Yay; 1221 } 1222 1223 case CK_IntegralCast: 1224 case CK_IntegralToFloating: 1225 case CK_FloatingToIntegral: 1226 case CK_FloatingCast: 1227 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 1228 case CK_IntegralToBoolean: 1229 return EmitIntToBoolConversion(Visit(E)); 1230 case CK_PointerToBoolean: 1231 return EmitPointerToBoolConversion(Visit(E)); 1232 case CK_FloatingToBoolean: 1233 return EmitFloatToBoolConversion(Visit(E)); 1234 case CK_MemberPointerToBoolean: { 1235 llvm::Value *MemPtr = Visit(E); 1236 const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>(); 1237 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT); 1238 } 1239 1240 case CK_FloatingComplexToReal: 1241 case CK_IntegralComplexToReal: 1242 return CGF.EmitComplexExpr(E, false, true).first; 1243 1244 case CK_FloatingComplexToBoolean: 1245 case CK_IntegralComplexToBoolean: { 1246 CodeGenFunction::ComplexPairTy V = CGF.EmitComplexExpr(E); 1247 1248 // TODO: kill this function off, inline appropriate case here 1249 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 1250 } 1251 1252 } 1253 1254 llvm_unreachable("unknown scalar cast"); 1255 return 0; 1256 } 1257 1258 Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 1259 CodeGenFunction::StmtExprEvaluation eval(CGF); 1260 return CGF.EmitCompoundStmt(*E->getSubStmt(), !E->getType()->isVoidType()) 1261 .getScalarVal(); 1262 } 1263 1264 Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 1265 LValue LV = CGF.EmitBlockDeclRefLValue(E); 1266 return CGF.EmitLoadOfLValue(LV).getScalarVal(); 1267 } 1268 1269 //===----------------------------------------------------------------------===// 1270 // Unary Operators 1271 //===----------------------------------------------------------------------===// 1272 1273 llvm::Value *ScalarExprEmitter:: 1274 EmitAddConsiderOverflowBehavior(const UnaryOperator *E, 1275 llvm::Value *InVal, 1276 llvm::Value *NextVal, bool IsInc) { 1277 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1278 case LangOptions::SOB_Undefined: 1279 return Builder.CreateNSWAdd(InVal, NextVal, IsInc ? "inc" : "dec"); 1280 break; 1281 case LangOptions::SOB_Defined: 1282 return Builder.CreateAdd(InVal, NextVal, IsInc ? "inc" : "dec"); 1283 break; 1284 case LangOptions::SOB_Trapping: 1285 BinOpInfo BinOp; 1286 BinOp.LHS = InVal; 1287 BinOp.RHS = NextVal; 1288 BinOp.Ty = E->getType(); 1289 BinOp.Opcode = BO_Add; 1290 BinOp.E = E; 1291 return EmitOverflowCheckedBinOp(BinOp); 1292 } 1293 llvm_unreachable("Unknown SignedOverflowBehaviorTy"); 1294 } 1295 1296 llvm::Value * 1297 ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 1298 bool isInc, bool isPre) { 1299 1300 QualType type = E->getSubExpr()->getType(); 1301 llvm::Value *value = EmitLoadOfLValue(LV); 1302 llvm::Value *input = value; 1303 1304 int amount = (isInc ? 1 : -1); 1305 1306 // Special case of integer increment that we have to check first: bool++. 1307 // Due to promotion rules, we get: 1308 // bool++ -> bool = bool + 1 1309 // -> bool = (int)bool + 1 1310 // -> bool = ((int)bool + 1 != 0) 1311 // An interesting aspect of this is that increment is always true. 1312 // Decrement does not have this property. 1313 if (isInc && type->isBooleanType()) { 1314 value = Builder.getTrue(); 1315 1316 // Most common case by far: integer increment. 1317 } else if (type->isIntegerType()) { 1318 1319 llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount); 1320 1321 // Note that signed integer inc/dec with width less than int can't 1322 // overflow because of promotion rules; we're just eliding a few steps here. 1323 if (type->isSignedIntegerOrEnumerationType() && 1324 value->getType()->getPrimitiveSizeInBits() >= 1325 CGF.IntTy->getBitWidth()) 1326 value = EmitAddConsiderOverflowBehavior(E, value, amt, isInc); 1327 else 1328 value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec"); 1329 1330 // Next most common: pointer increment. 1331 } else if (const PointerType *ptr = type->getAs<PointerType>()) { 1332 QualType type = ptr->getPointeeType(); 1333 1334 // VLA types don't have constant size. 1335 if (const VariableArrayType *vla 1336 = CGF.getContext().getAsVariableArrayType(type)) { 1337 llvm::Value *numElts = CGF.getVLASize(vla).first; 1338 if (!isInc) numElts = Builder.CreateNSWNeg(numElts, "vla.negsize"); 1339 if (CGF.getContext().getLangOptions().isSignedOverflowDefined()) 1340 value = Builder.CreateGEP(value, numElts, "vla.inc"); 1341 else 1342 value = Builder.CreateInBoundsGEP(value, numElts, "vla.inc"); 1343 1344 // Arithmetic on function pointers (!) is just +-1. 1345 } else if (type->isFunctionType()) { 1346 llvm::Value *amt = Builder.getInt32(amount); 1347 1348 value = CGF.EmitCastToVoidPtr(value); 1349 if (CGF.getContext().getLangOptions().isSignedOverflowDefined()) 1350 value = Builder.CreateGEP(value, amt, "incdec.funcptr"); 1351 else 1352 value = Builder.CreateInBoundsGEP(value, amt, "incdec.funcptr"); 1353 value = Builder.CreateBitCast(value, input->getType()); 1354 1355 // For everything else, we can just do a simple increment. 1356 } else { 1357 llvm::Value *amt = Builder.getInt32(amount); 1358 if (CGF.getContext().getLangOptions().isSignedOverflowDefined()) 1359 value = Builder.CreateGEP(value, amt, "incdec.ptr"); 1360 else 1361 value = Builder.CreateInBoundsGEP(value, amt, "incdec.ptr"); 1362 } 1363 1364 // Vector increment/decrement. 1365 } else if (type->isVectorType()) { 1366 if (type->hasIntegerRepresentation()) { 1367 llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount); 1368 1369 value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec"); 1370 } else { 1371 value = Builder.CreateFAdd( 1372 value, 1373 llvm::ConstantFP::get(value->getType(), amount), 1374 isInc ? "inc" : "dec"); 1375 } 1376 1377 // Floating point. 1378 } else if (type->isRealFloatingType()) { 1379 // Add the inc/dec to the real part. 1380 llvm::Value *amt; 1381 1382 if (type->isHalfType()) { 1383 // Another special case: half FP increment should be done via float 1384 value = 1385 Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16), 1386 input); 1387 } 1388 1389 if (value->getType()->isFloatTy()) 1390 amt = llvm::ConstantFP::get(VMContext, 1391 llvm::APFloat(static_cast<float>(amount))); 1392 else if (value->getType()->isDoubleTy()) 1393 amt = llvm::ConstantFP::get(VMContext, 1394 llvm::APFloat(static_cast<double>(amount))); 1395 else { 1396 llvm::APFloat F(static_cast<float>(amount)); 1397 bool ignored; 1398 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, 1399 &ignored); 1400 amt = llvm::ConstantFP::get(VMContext, F); 1401 } 1402 value = Builder.CreateFAdd(value, amt, isInc ? "inc" : "dec"); 1403 1404 if (type->isHalfType()) 1405 value = 1406 Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16), 1407 value); 1408 1409 // Objective-C pointer types. 1410 } else { 1411 const ObjCObjectPointerType *OPT = type->castAs<ObjCObjectPointerType>(); 1412 value = CGF.EmitCastToVoidPtr(value); 1413 1414 CharUnits size = CGF.getContext().getTypeSizeInChars(OPT->getObjectType()); 1415 if (!isInc) size = -size; 1416 llvm::Value *sizeValue = 1417 llvm::ConstantInt::get(CGF.SizeTy, size.getQuantity()); 1418 1419 if (CGF.getContext().getLangOptions().isSignedOverflowDefined()) 1420 value = Builder.CreateGEP(value, sizeValue, "incdec.objptr"); 1421 else 1422 value = Builder.CreateInBoundsGEP(value, sizeValue, "incdec.objptr"); 1423 value = Builder.CreateBitCast(value, input->getType()); 1424 } 1425 1426 // Store the updated result through the lvalue. 1427 if (LV.isBitField()) 1428 CGF.EmitStoreThroughBitfieldLValue(RValue::get(value), LV, &value); 1429 else 1430 CGF.EmitStoreThroughLValue(RValue::get(value), LV); 1431 1432 // If this is a postinc, return the value read from memory, otherwise use the 1433 // updated value. 1434 return isPre ? value : input; 1435 } 1436 1437 1438 1439 Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1440 TestAndClearIgnoreResultAssign(); 1441 // Emit unary minus with EmitSub so we handle overflow cases etc. 1442 BinOpInfo BinOp; 1443 BinOp.RHS = Visit(E->getSubExpr()); 1444 1445 if (BinOp.RHS->getType()->isFPOrFPVectorTy()) 1446 BinOp.LHS = llvm::ConstantFP::getZeroValueForNegation(BinOp.RHS->getType()); 1447 else 1448 BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType()); 1449 BinOp.Ty = E->getType(); 1450 BinOp.Opcode = BO_Sub; 1451 BinOp.E = E; 1452 return EmitSub(BinOp); 1453 } 1454 1455 Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1456 TestAndClearIgnoreResultAssign(); 1457 Value *Op = Visit(E->getSubExpr()); 1458 return Builder.CreateNot(Op, "neg"); 1459 } 1460 1461 Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1462 // Compare operand to zero. 1463 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1464 1465 // Invert value. 1466 // TODO: Could dynamically modify easy computations here. For example, if 1467 // the operand is an icmp ne, turn into icmp eq. 1468 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1469 1470 // ZExt result to the expr type. 1471 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1472 } 1473 1474 Value *ScalarExprEmitter::VisitOffsetOfExpr(OffsetOfExpr *E) { 1475 // Try folding the offsetof to a constant. 1476 Expr::EvalResult EvalResult; 1477 if (E->Evaluate(EvalResult, CGF.getContext())) 1478 return Builder.getInt(EvalResult.Val.getInt()); 1479 1480 // Loop over the components of the offsetof to compute the value. 1481 unsigned n = E->getNumComponents(); 1482 llvm::Type* ResultType = ConvertType(E->getType()); 1483 llvm::Value* Result = llvm::Constant::getNullValue(ResultType); 1484 QualType CurrentType = E->getTypeSourceInfo()->getType(); 1485 for (unsigned i = 0; i != n; ++i) { 1486 OffsetOfExpr::OffsetOfNode ON = E->getComponent(i); 1487 llvm::Value *Offset = 0; 1488 switch (ON.getKind()) { 1489 case OffsetOfExpr::OffsetOfNode::Array: { 1490 // Compute the index 1491 Expr *IdxExpr = E->getIndexExpr(ON.getArrayExprIndex()); 1492 llvm::Value* Idx = CGF.EmitScalarExpr(IdxExpr); 1493 bool IdxSigned = IdxExpr->getType()->isSignedIntegerOrEnumerationType(); 1494 Idx = Builder.CreateIntCast(Idx, ResultType, IdxSigned, "conv"); 1495 1496 // Save the element type 1497 CurrentType = 1498 CGF.getContext().getAsArrayType(CurrentType)->getElementType(); 1499 1500 // Compute the element size 1501 llvm::Value* ElemSize = llvm::ConstantInt::get(ResultType, 1502 CGF.getContext().getTypeSizeInChars(CurrentType).getQuantity()); 1503 1504 // Multiply out to compute the result 1505 Offset = Builder.CreateMul(Idx, ElemSize); 1506 break; 1507 } 1508 1509 case OffsetOfExpr::OffsetOfNode::Field: { 1510 FieldDecl *MemberDecl = ON.getField(); 1511 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1512 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1513 1514 // Compute the index of the field in its parent. 1515 unsigned i = 0; 1516 // FIXME: It would be nice if we didn't have to loop here! 1517 for (RecordDecl::field_iterator Field = RD->field_begin(), 1518 FieldEnd = RD->field_end(); 1519 Field != FieldEnd; (void)++Field, ++i) { 1520 if (*Field == MemberDecl) 1521 break; 1522 } 1523 assert(i < RL.getFieldCount() && "offsetof field in wrong type"); 1524 1525 // Compute the offset to the field 1526 int64_t OffsetInt = RL.getFieldOffset(i) / 1527 CGF.getContext().getCharWidth(); 1528 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1529 1530 // Save the element type. 1531 CurrentType = MemberDecl->getType(); 1532 break; 1533 } 1534 1535 case OffsetOfExpr::OffsetOfNode::Identifier: 1536 llvm_unreachable("dependent __builtin_offsetof"); 1537 1538 case OffsetOfExpr::OffsetOfNode::Base: { 1539 if (ON.getBase()->isVirtual()) { 1540 CGF.ErrorUnsupported(E, "virtual base in offsetof"); 1541 continue; 1542 } 1543 1544 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1545 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1546 1547 // Save the element type. 1548 CurrentType = ON.getBase()->getType(); 1549 1550 // Compute the offset to the base. 1551 const RecordType *BaseRT = CurrentType->getAs<RecordType>(); 1552 CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl()); 1553 int64_t OffsetInt = RL.getBaseClassOffsetInBits(BaseRD) / 1554 CGF.getContext().getCharWidth(); 1555 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1556 break; 1557 } 1558 } 1559 Result = Builder.CreateAdd(Result, Offset); 1560 } 1561 return Result; 1562 } 1563 1564 /// VisitUnaryExprOrTypeTraitExpr - Return the size or alignment of the type of 1565 /// argument of the sizeof expression as an integer. 1566 Value * 1567 ScalarExprEmitter::VisitUnaryExprOrTypeTraitExpr( 1568 const UnaryExprOrTypeTraitExpr *E) { 1569 QualType TypeToSize = E->getTypeOfArgument(); 1570 if (E->getKind() == UETT_SizeOf) { 1571 if (const VariableArrayType *VAT = 1572 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1573 if (E->isArgumentType()) { 1574 // sizeof(type) - make sure to emit the VLA size. 1575 CGF.EmitVariablyModifiedType(TypeToSize); 1576 } else { 1577 // C99 6.5.3.4p2: If the argument is an expression of type 1578 // VLA, it is evaluated. 1579 CGF.EmitIgnoredExpr(E->getArgumentExpr()); 1580 } 1581 1582 QualType eltType; 1583 llvm::Value *numElts; 1584 llvm::tie(numElts, eltType) = CGF.getVLASize(VAT); 1585 1586 llvm::Value *size = numElts; 1587 1588 // Scale the number of non-VLA elements by the non-VLA element size. 1589 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType); 1590 if (!eltSize.isOne()) 1591 size = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), numElts); 1592 1593 return size; 1594 } 1595 } 1596 1597 // If this isn't sizeof(vla), the result must be constant; use the constant 1598 // folding logic so we don't have to duplicate it here. 1599 Expr::EvalResult Result; 1600 E->Evaluate(Result, CGF.getContext()); 1601 return Builder.getInt(Result.Val.getInt()); 1602 } 1603 1604 Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1605 Expr *Op = E->getSubExpr(); 1606 if (Op->getType()->isAnyComplexType()) { 1607 // If it's an l-value, load through the appropriate subobject l-value. 1608 // Note that we have to ask E because Op might be an l-value that 1609 // this won't work for, e.g. an Obj-C property. 1610 if (E->isGLValue()) 1611 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E)).getScalarVal(); 1612 1613 // Otherwise, calculate and project. 1614 return CGF.EmitComplexExpr(Op, false, true).first; 1615 } 1616 1617 return Visit(Op); 1618 } 1619 1620 Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1621 Expr *Op = E->getSubExpr(); 1622 if (Op->getType()->isAnyComplexType()) { 1623 // If it's an l-value, load through the appropriate subobject l-value. 1624 // Note that we have to ask E because Op might be an l-value that 1625 // this won't work for, e.g. an Obj-C property. 1626 if (Op->isGLValue()) 1627 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E)).getScalarVal(); 1628 1629 // Otherwise, calculate and project. 1630 return CGF.EmitComplexExpr(Op, true, false).second; 1631 } 1632 1633 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1634 // effects are evaluated, but not the actual value. 1635 CGF.EmitScalarExpr(Op, true); 1636 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1637 } 1638 1639 //===----------------------------------------------------------------------===// 1640 // Binary Operators 1641 //===----------------------------------------------------------------------===// 1642 1643 BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1644 TestAndClearIgnoreResultAssign(); 1645 BinOpInfo Result; 1646 Result.LHS = Visit(E->getLHS()); 1647 Result.RHS = Visit(E->getRHS()); 1648 Result.Ty = E->getType(); 1649 Result.Opcode = E->getOpcode(); 1650 Result.E = E; 1651 return Result; 1652 } 1653 1654 LValue ScalarExprEmitter::EmitCompoundAssignLValue( 1655 const CompoundAssignOperator *E, 1656 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &), 1657 Value *&Result) { 1658 QualType LHSTy = E->getLHS()->getType(); 1659 BinOpInfo OpInfo; 1660 1661 if (E->getComputationResultType()->isAnyComplexType()) { 1662 // This needs to go through the complex expression emitter, but it's a tad 1663 // complicated to do that... I'm leaving it out for now. (Note that we do 1664 // actually need the imaginary part of the RHS for multiplication and 1665 // division.) 1666 CGF.ErrorUnsupported(E, "complex compound assignment"); 1667 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType())); 1668 return LValue(); 1669 } 1670 1671 // Emit the RHS first. __block variables need to have the rhs evaluated 1672 // first, plus this should improve codegen a little. 1673 OpInfo.RHS = Visit(E->getRHS()); 1674 OpInfo.Ty = E->getComputationResultType(); 1675 OpInfo.Opcode = E->getOpcode(); 1676 OpInfo.E = E; 1677 // Load/convert the LHS. 1678 LValue LHSLV = EmitCheckedLValue(E->getLHS()); 1679 OpInfo.LHS = EmitLoadOfLValue(LHSLV); 1680 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 1681 E->getComputationLHSType()); 1682 1683 // Expand the binary operator. 1684 Result = (this->*Func)(OpInfo); 1685 1686 // Convert the result back to the LHS type. 1687 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 1688 1689 // Store the result value into the LHS lvalue. Bit-fields are handled 1690 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 1691 // 'An assignment expression has the value of the left operand after the 1692 // assignment...'. 1693 if (LHSLV.isBitField()) 1694 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, &Result); 1695 else 1696 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV); 1697 1698 return LHSLV; 1699 } 1700 1701 Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 1702 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 1703 bool Ignore = TestAndClearIgnoreResultAssign(); 1704 Value *RHS; 1705 LValue LHS = EmitCompoundAssignLValue(E, Func, RHS); 1706 1707 // If the result is clearly ignored, return now. 1708 if (Ignore) 1709 return 0; 1710 1711 // The result of an assignment in C is the assigned r-value. 1712 if (!CGF.getContext().getLangOptions().CPlusPlus) 1713 return RHS; 1714 1715 // Objective-C property assignment never reloads the value following a store. 1716 if (LHS.isPropertyRef()) 1717 return RHS; 1718 1719 // If the lvalue is non-volatile, return the computed value of the assignment. 1720 if (!LHS.isVolatileQualified()) 1721 return RHS; 1722 1723 // Otherwise, reload the value. 1724 return EmitLoadOfLValue(LHS); 1725 } 1726 1727 void ScalarExprEmitter::EmitUndefinedBehaviorIntegerDivAndRemCheck( 1728 const BinOpInfo &Ops, 1729 llvm::Value *Zero, bool isDiv) { 1730 llvm::Function::iterator insertPt = Builder.GetInsertBlock(); 1731 llvm::BasicBlock *contBB = 1732 CGF.createBasicBlock(isDiv ? "div.cont" : "rem.cont", CGF.CurFn, 1733 llvm::next(insertPt)); 1734 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); 1735 1736 llvm::IntegerType *Ty = cast<llvm::IntegerType>(Zero->getType()); 1737 1738 if (Ops.Ty->hasSignedIntegerRepresentation()) { 1739 llvm::Value *IntMin = 1740 Builder.getInt(llvm::APInt::getSignedMinValue(Ty->getBitWidth())); 1741 llvm::Value *NegOne = llvm::ConstantInt::get(Ty, -1ULL); 1742 1743 llvm::Value *Cond1 = Builder.CreateICmpEQ(Ops.RHS, Zero); 1744 llvm::Value *LHSCmp = Builder.CreateICmpEQ(Ops.LHS, IntMin); 1745 llvm::Value *RHSCmp = Builder.CreateICmpEQ(Ops.RHS, NegOne); 1746 llvm::Value *Cond2 = Builder.CreateAnd(LHSCmp, RHSCmp, "and"); 1747 Builder.CreateCondBr(Builder.CreateOr(Cond1, Cond2, "or"), 1748 overflowBB, contBB); 1749 } else { 1750 CGF.Builder.CreateCondBr(Builder.CreateICmpEQ(Ops.RHS, Zero), 1751 overflowBB, contBB); 1752 } 1753 EmitOverflowBB(overflowBB); 1754 Builder.SetInsertPoint(contBB); 1755 } 1756 1757 Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 1758 if (isTrapvOverflowBehavior()) { 1759 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 1760 1761 if (Ops.Ty->isIntegerType()) 1762 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, true); 1763 else if (Ops.Ty->isRealFloatingType()) { 1764 llvm::Function::iterator insertPt = Builder.GetInsertBlock(); 1765 llvm::BasicBlock *DivCont = CGF.createBasicBlock("div.cont", CGF.CurFn, 1766 llvm::next(insertPt)); 1767 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", 1768 CGF.CurFn); 1769 CGF.Builder.CreateCondBr(Builder.CreateFCmpOEQ(Ops.RHS, Zero), 1770 overflowBB, DivCont); 1771 EmitOverflowBB(overflowBB); 1772 Builder.SetInsertPoint(DivCont); 1773 } 1774 } 1775 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1776 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 1777 else if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1778 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 1779 else 1780 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 1781 } 1782 1783 Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 1784 // Rem in C can't be a floating point type: C99 6.5.5p2. 1785 if (isTrapvOverflowBehavior()) { 1786 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 1787 1788 if (Ops.Ty->isIntegerType()) 1789 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, false); 1790 } 1791 1792 if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1793 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 1794 else 1795 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 1796 } 1797 1798 Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 1799 unsigned IID; 1800 unsigned OpID = 0; 1801 1802 switch (Ops.Opcode) { 1803 case BO_Add: 1804 case BO_AddAssign: 1805 OpID = 1; 1806 IID = llvm::Intrinsic::sadd_with_overflow; 1807 break; 1808 case BO_Sub: 1809 case BO_SubAssign: 1810 OpID = 2; 1811 IID = llvm::Intrinsic::ssub_with_overflow; 1812 break; 1813 case BO_Mul: 1814 case BO_MulAssign: 1815 OpID = 3; 1816 IID = llvm::Intrinsic::smul_with_overflow; 1817 break; 1818 default: 1819 llvm_unreachable("Unsupported operation for overflow detection"); 1820 IID = 0; 1821 } 1822 OpID <<= 1; 1823 OpID |= 1; 1824 1825 llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1826 1827 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, opTy); 1828 1829 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1830 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1831 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1832 1833 // Branch in case of overflow. 1834 llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); 1835 llvm::Function::iterator insertPt = initialBB; 1836 llvm::BasicBlock *continueBB = CGF.createBasicBlock("nooverflow", CGF.CurFn, 1837 llvm::next(insertPt)); 1838 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); 1839 1840 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1841 1842 // Handle overflow with llvm.trap. 1843 const std::string *handlerName = 1844 &CGF.getContext().getLangOptions().OverflowHandler; 1845 if (handlerName->empty()) { 1846 EmitOverflowBB(overflowBB); 1847 Builder.SetInsertPoint(continueBB); 1848 return result; 1849 } 1850 1851 // If an overflow handler is set, then we want to call it and then use its 1852 // result, if it returns. 1853 Builder.SetInsertPoint(overflowBB); 1854 1855 // Get the overflow handler. 1856 llvm::Type *Int8Ty = llvm::Type::getInt8Ty(VMContext); 1857 llvm::Type *argTypes[] = { CGF.Int64Ty, CGF.Int64Ty, Int8Ty, Int8Ty }; 1858 llvm::FunctionType *handlerTy = 1859 llvm::FunctionType::get(CGF.Int64Ty, argTypes, true); 1860 llvm::Value *handler = CGF.CGM.CreateRuntimeFunction(handlerTy, *handlerName); 1861 1862 // Sign extend the args to 64-bit, so that we can use the same handler for 1863 // all types of overflow. 1864 llvm::Value *lhs = Builder.CreateSExt(Ops.LHS, CGF.Int64Ty); 1865 llvm::Value *rhs = Builder.CreateSExt(Ops.RHS, CGF.Int64Ty); 1866 1867 // Call the handler with the two arguments, the operation, and the size of 1868 // the result. 1869 llvm::Value *handlerResult = Builder.CreateCall4(handler, lhs, rhs, 1870 Builder.getInt8(OpID), 1871 Builder.getInt8(cast<llvm::IntegerType>(opTy)->getBitWidth())); 1872 1873 // Truncate the result back to the desired size. 1874 handlerResult = Builder.CreateTrunc(handlerResult, opTy); 1875 Builder.CreateBr(continueBB); 1876 1877 Builder.SetInsertPoint(continueBB); 1878 llvm::PHINode *phi = Builder.CreatePHI(opTy, 2); 1879 phi->addIncoming(result, initialBB); 1880 phi->addIncoming(handlerResult, overflowBB); 1881 1882 return phi; 1883 } 1884 1885 /// Emit pointer + index arithmetic. 1886 static Value *emitPointerArithmetic(CodeGenFunction &CGF, 1887 const BinOpInfo &op, 1888 bool isSubtraction) { 1889 // Must have binary (not unary) expr here. Unary pointer 1890 // increment/decrement doesn't use this path. 1891 const BinaryOperator *expr = cast<BinaryOperator>(op.E); 1892 1893 Value *pointer = op.LHS; 1894 Expr *pointerOperand = expr->getLHS(); 1895 Value *index = op.RHS; 1896 Expr *indexOperand = expr->getRHS(); 1897 1898 // In a subtraction, the LHS is always the pointer. 1899 if (!isSubtraction && !pointer->getType()->isPointerTy()) { 1900 std::swap(pointer, index); 1901 std::swap(pointerOperand, indexOperand); 1902 } 1903 1904 unsigned width = cast<llvm::IntegerType>(index->getType())->getBitWidth(); 1905 if (width != CGF.PointerWidthInBits) { 1906 // Zero-extend or sign-extend the pointer value according to 1907 // whether the index is signed or not. 1908 bool isSigned = indexOperand->getType()->isSignedIntegerOrEnumerationType(); 1909 index = CGF.Builder.CreateIntCast(index, CGF.PtrDiffTy, isSigned, 1910 "idx.ext"); 1911 } 1912 1913 // If this is subtraction, negate the index. 1914 if (isSubtraction) 1915 index = CGF.Builder.CreateNeg(index, "idx.neg"); 1916 1917 const PointerType *pointerType 1918 = pointerOperand->getType()->getAs<PointerType>(); 1919 if (!pointerType) { 1920 QualType objectType = pointerOperand->getType() 1921 ->castAs<ObjCObjectPointerType>() 1922 ->getPointeeType(); 1923 llvm::Value *objectSize 1924 = CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(objectType)); 1925 1926 index = CGF.Builder.CreateMul(index, objectSize); 1927 1928 Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy); 1929 result = CGF.Builder.CreateGEP(result, index, "add.ptr"); 1930 return CGF.Builder.CreateBitCast(result, pointer->getType()); 1931 } 1932 1933 QualType elementType = pointerType->getPointeeType(); 1934 if (const VariableArrayType *vla 1935 = CGF.getContext().getAsVariableArrayType(elementType)) { 1936 // The element count here is the total number of non-VLA elements. 1937 llvm::Value *numElements = CGF.getVLASize(vla).first; 1938 1939 // Effectively, the multiply by the VLA size is part of the GEP. 1940 // GEP indexes are signed, and scaling an index isn't permitted to 1941 // signed-overflow, so we use the same semantics for our explicit 1942 // multiply. We suppress this if overflow is not undefined behavior. 1943 if (CGF.getLangOptions().isSignedOverflowDefined()) { 1944 index = CGF.Builder.CreateMul(index, numElements, "vla.index"); 1945 pointer = CGF.Builder.CreateGEP(pointer, index, "add.ptr"); 1946 } else { 1947 index = CGF.Builder.CreateNSWMul(index, numElements, "vla.index"); 1948 pointer = CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr"); 1949 } 1950 return pointer; 1951 } 1952 1953 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 1954 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 1955 // future proof. 1956 if (elementType->isVoidType() || elementType->isFunctionType()) { 1957 Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy); 1958 result = CGF.Builder.CreateGEP(result, index, "add.ptr"); 1959 return CGF.Builder.CreateBitCast(result, pointer->getType()); 1960 } 1961 1962 if (CGF.getLangOptions().isSignedOverflowDefined()) 1963 return CGF.Builder.CreateGEP(pointer, index, "add.ptr"); 1964 1965 return CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr"); 1966 } 1967 1968 Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &op) { 1969 if (op.LHS->getType()->isPointerTy() || 1970 op.RHS->getType()->isPointerTy()) 1971 return emitPointerArithmetic(CGF, op, /*subtraction*/ false); 1972 1973 if (op.Ty->isSignedIntegerOrEnumerationType()) { 1974 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1975 case LangOptions::SOB_Undefined: 1976 return Builder.CreateNSWAdd(op.LHS, op.RHS, "add"); 1977 case LangOptions::SOB_Defined: 1978 return Builder.CreateAdd(op.LHS, op.RHS, "add"); 1979 case LangOptions::SOB_Trapping: 1980 return EmitOverflowCheckedBinOp(op); 1981 } 1982 } 1983 1984 if (op.LHS->getType()->isFPOrFPVectorTy()) 1985 return Builder.CreateFAdd(op.LHS, op.RHS, "add"); 1986 1987 return Builder.CreateAdd(op.LHS, op.RHS, "add"); 1988 } 1989 1990 Value *ScalarExprEmitter::EmitSub(const BinOpInfo &op) { 1991 // The LHS is always a pointer if either side is. 1992 if (!op.LHS->getType()->isPointerTy()) { 1993 if (op.Ty->isSignedIntegerOrEnumerationType()) { 1994 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1995 case LangOptions::SOB_Undefined: 1996 return Builder.CreateNSWSub(op.LHS, op.RHS, "sub"); 1997 case LangOptions::SOB_Defined: 1998 return Builder.CreateSub(op.LHS, op.RHS, "sub"); 1999 case LangOptions::SOB_Trapping: 2000 return EmitOverflowCheckedBinOp(op); 2001 } 2002 } 2003 2004 if (op.LHS->getType()->isFPOrFPVectorTy()) 2005 return Builder.CreateFSub(op.LHS, op.RHS, "sub"); 2006 2007 return Builder.CreateSub(op.LHS, op.RHS, "sub"); 2008 } 2009 2010 // If the RHS is not a pointer, then we have normal pointer 2011 // arithmetic. 2012 if (!op.RHS->getType()->isPointerTy()) 2013 return emitPointerArithmetic(CGF, op, /*subtraction*/ true); 2014 2015 // Otherwise, this is a pointer subtraction. 2016 2017 // Do the raw subtraction part. 2018 llvm::Value *LHS 2019 = Builder.CreatePtrToInt(op.LHS, CGF.PtrDiffTy, "sub.ptr.lhs.cast"); 2020 llvm::Value *RHS 2021 = Builder.CreatePtrToInt(op.RHS, CGF.PtrDiffTy, "sub.ptr.rhs.cast"); 2022 Value *diffInChars = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 2023 2024 // Okay, figure out the element size. 2025 const BinaryOperator *expr = cast<BinaryOperator>(op.E); 2026 QualType elementType = expr->getLHS()->getType()->getPointeeType(); 2027 2028 llvm::Value *divisor = 0; 2029 2030 // For a variable-length array, this is going to be non-constant. 2031 if (const VariableArrayType *vla 2032 = CGF.getContext().getAsVariableArrayType(elementType)) { 2033 llvm::Value *numElements; 2034 llvm::tie(numElements, elementType) = CGF.getVLASize(vla); 2035 2036 divisor = numElements; 2037 2038 // Scale the number of non-VLA elements by the non-VLA element size. 2039 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(elementType); 2040 if (!eltSize.isOne()) 2041 divisor = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), divisor); 2042 2043 // For everything elese, we can just compute it, safe in the 2044 // assumption that Sema won't let anything through that we can't 2045 // safely compute the size of. 2046 } else { 2047 CharUnits elementSize; 2048 // Handle GCC extension for pointer arithmetic on void* and 2049 // function pointer types. 2050 if (elementType->isVoidType() || elementType->isFunctionType()) 2051 elementSize = CharUnits::One(); 2052 else 2053 elementSize = CGF.getContext().getTypeSizeInChars(elementType); 2054 2055 // Don't even emit the divide for element size of 1. 2056 if (elementSize.isOne()) 2057 return diffInChars; 2058 2059 divisor = CGF.CGM.getSize(elementSize); 2060 } 2061 2062 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 2063 // pointer difference in C is only defined in the case where both operands 2064 // are pointing to elements of an array. 2065 return Builder.CreateExactSDiv(diffInChars, divisor, "sub.ptr.div"); 2066 } 2067 2068 Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 2069 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 2070 // RHS to the same size as the LHS. 2071 Value *RHS = Ops.RHS; 2072 if (Ops.LHS->getType() != RHS->getType()) 2073 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 2074 2075 if (CGF.CatchUndefined 2076 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 2077 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 2078 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 2079 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 2080 llvm::ConstantInt::get(RHS->getType(), Width)), 2081 Cont, CGF.getTrapBB()); 2082 CGF.EmitBlock(Cont); 2083 } 2084 2085 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 2086 } 2087 2088 Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 2089 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 2090 // RHS to the same size as the LHS. 2091 Value *RHS = Ops.RHS; 2092 if (Ops.LHS->getType() != RHS->getType()) 2093 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 2094 2095 if (CGF.CatchUndefined 2096 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 2097 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 2098 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 2099 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 2100 llvm::ConstantInt::get(RHS->getType(), Width)), 2101 Cont, CGF.getTrapBB()); 2102 CGF.EmitBlock(Cont); 2103 } 2104 2105 if (Ops.Ty->hasUnsignedIntegerRepresentation()) 2106 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 2107 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 2108 } 2109 2110 enum IntrinsicType { VCMPEQ, VCMPGT }; 2111 // return corresponding comparison intrinsic for given vector type 2112 static llvm::Intrinsic::ID GetIntrinsic(IntrinsicType IT, 2113 BuiltinType::Kind ElemKind) { 2114 switch (ElemKind) { 2115 default: llvm_unreachable("unexpected element type"); 2116 case BuiltinType::Char_U: 2117 case BuiltinType::UChar: 2118 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p : 2119 llvm::Intrinsic::ppc_altivec_vcmpgtub_p; 2120 break; 2121 case BuiltinType::Char_S: 2122 case BuiltinType::SChar: 2123 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p : 2124 llvm::Intrinsic::ppc_altivec_vcmpgtsb_p; 2125 break; 2126 case BuiltinType::UShort: 2127 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p : 2128 llvm::Intrinsic::ppc_altivec_vcmpgtuh_p; 2129 break; 2130 case BuiltinType::Short: 2131 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p : 2132 llvm::Intrinsic::ppc_altivec_vcmpgtsh_p; 2133 break; 2134 case BuiltinType::UInt: 2135 case BuiltinType::ULong: 2136 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p : 2137 llvm::Intrinsic::ppc_altivec_vcmpgtuw_p; 2138 break; 2139 case BuiltinType::Int: 2140 case BuiltinType::Long: 2141 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p : 2142 llvm::Intrinsic::ppc_altivec_vcmpgtsw_p; 2143 break; 2144 case BuiltinType::Float: 2145 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpeqfp_p : 2146 llvm::Intrinsic::ppc_altivec_vcmpgtfp_p; 2147 break; 2148 } 2149 return llvm::Intrinsic::not_intrinsic; 2150 } 2151 2152 Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 2153 unsigned SICmpOpc, unsigned FCmpOpc) { 2154 TestAndClearIgnoreResultAssign(); 2155 Value *Result; 2156 QualType LHSTy = E->getLHS()->getType(); 2157 if (const MemberPointerType *MPT = LHSTy->getAs<MemberPointerType>()) { 2158 assert(E->getOpcode() == BO_EQ || 2159 E->getOpcode() == BO_NE); 2160 Value *LHS = CGF.EmitScalarExpr(E->getLHS()); 2161 Value *RHS = CGF.EmitScalarExpr(E->getRHS()); 2162 Result = CGF.CGM.getCXXABI().EmitMemberPointerComparison( 2163 CGF, LHS, RHS, MPT, E->getOpcode() == BO_NE); 2164 } else if (!LHSTy->isAnyComplexType()) { 2165 Value *LHS = Visit(E->getLHS()); 2166 Value *RHS = Visit(E->getRHS()); 2167 2168 // If AltiVec, the comparison results in a numeric type, so we use 2169 // intrinsics comparing vectors and giving 0 or 1 as a result 2170 if (LHSTy->isVectorType() && !E->getType()->isVectorType()) { 2171 // constants for mapping CR6 register bits to predicate result 2172 enum { CR6_EQ=0, CR6_EQ_REV, CR6_LT, CR6_LT_REV } CR6; 2173 2174 llvm::Intrinsic::ID ID = llvm::Intrinsic::not_intrinsic; 2175 2176 // in several cases vector arguments order will be reversed 2177 Value *FirstVecArg = LHS, 2178 *SecondVecArg = RHS; 2179 2180 QualType ElTy = LHSTy->getAs<VectorType>()->getElementType(); 2181 const BuiltinType *BTy = ElTy->getAs<BuiltinType>(); 2182 BuiltinType::Kind ElementKind = BTy->getKind(); 2183 2184 switch(E->getOpcode()) { 2185 default: llvm_unreachable("is not a comparison operation"); 2186 case BO_EQ: 2187 CR6 = CR6_LT; 2188 ID = GetIntrinsic(VCMPEQ, ElementKind); 2189 break; 2190 case BO_NE: 2191 CR6 = CR6_EQ; 2192 ID = GetIntrinsic(VCMPEQ, ElementKind); 2193 break; 2194 case BO_LT: 2195 CR6 = CR6_LT; 2196 ID = GetIntrinsic(VCMPGT, ElementKind); 2197 std::swap(FirstVecArg, SecondVecArg); 2198 break; 2199 case BO_GT: 2200 CR6 = CR6_LT; 2201 ID = GetIntrinsic(VCMPGT, ElementKind); 2202 break; 2203 case BO_LE: 2204 if (ElementKind == BuiltinType::Float) { 2205 CR6 = CR6_LT; 2206 ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p; 2207 std::swap(FirstVecArg, SecondVecArg); 2208 } 2209 else { 2210 CR6 = CR6_EQ; 2211 ID = GetIntrinsic(VCMPGT, ElementKind); 2212 } 2213 break; 2214 case BO_GE: 2215 if (ElementKind == BuiltinType::Float) { 2216 CR6 = CR6_LT; 2217 ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p; 2218 } 2219 else { 2220 CR6 = CR6_EQ; 2221 ID = GetIntrinsic(VCMPGT, ElementKind); 2222 std::swap(FirstVecArg, SecondVecArg); 2223 } 2224 break; 2225 } 2226 2227 Value *CR6Param = Builder.getInt32(CR6); 2228 llvm::Function *F = CGF.CGM.getIntrinsic(ID); 2229 Result = Builder.CreateCall3(F, CR6Param, FirstVecArg, SecondVecArg, ""); 2230 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 2231 } 2232 2233 if (LHS->getType()->isFPOrFPVectorTy()) { 2234 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 2235 LHS, RHS, "cmp"); 2236 } else if (LHSTy->hasSignedIntegerRepresentation()) { 2237 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 2238 LHS, RHS, "cmp"); 2239 } else { 2240 // Unsigned integers and pointers. 2241 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2242 LHS, RHS, "cmp"); 2243 } 2244 2245 // If this is a vector comparison, sign extend the result to the appropriate 2246 // vector integer type and return it (don't convert to bool). 2247 if (LHSTy->isVectorType()) 2248 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 2249 2250 } else { 2251 // Complex Comparison: can only be an equality comparison. 2252 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 2253 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 2254 2255 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 2256 2257 Value *ResultR, *ResultI; 2258 if (CETy->isRealFloatingType()) { 2259 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 2260 LHS.first, RHS.first, "cmp.r"); 2261 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 2262 LHS.second, RHS.second, "cmp.i"); 2263 } else { 2264 // Complex comparisons can only be equality comparisons. As such, signed 2265 // and unsigned opcodes are the same. 2266 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2267 LHS.first, RHS.first, "cmp.r"); 2268 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2269 LHS.second, RHS.second, "cmp.i"); 2270 } 2271 2272 if (E->getOpcode() == BO_EQ) { 2273 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 2274 } else { 2275 assert(E->getOpcode() == BO_NE && 2276 "Complex comparison other than == or != ?"); 2277 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 2278 } 2279 } 2280 2281 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 2282 } 2283 2284 Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 2285 bool Ignore = TestAndClearIgnoreResultAssign(); 2286 2287 Value *RHS; 2288 LValue LHS; 2289 2290 switch (E->getLHS()->getType().getObjCLifetime()) { 2291 case Qualifiers::OCL_Strong: 2292 llvm::tie(LHS, RHS) = CGF.EmitARCStoreStrong(E, Ignore); 2293 break; 2294 2295 case Qualifiers::OCL_Autoreleasing: 2296 llvm::tie(LHS,RHS) = CGF.EmitARCStoreAutoreleasing(E); 2297 break; 2298 2299 case Qualifiers::OCL_Weak: 2300 RHS = Visit(E->getRHS()); 2301 LHS = EmitCheckedLValue(E->getLHS()); 2302 RHS = CGF.EmitARCStoreWeak(LHS.getAddress(), RHS, Ignore); 2303 break; 2304 2305 // No reason to do any of these differently. 2306 case Qualifiers::OCL_None: 2307 case Qualifiers::OCL_ExplicitNone: 2308 // __block variables need to have the rhs evaluated first, plus 2309 // this should improve codegen just a little. 2310 RHS = Visit(E->getRHS()); 2311 LHS = EmitCheckedLValue(E->getLHS()); 2312 2313 // Store the value into the LHS. Bit-fields are handled specially 2314 // because the result is altered by the store, i.e., [C99 6.5.16p1] 2315 // 'An assignment expression has the value of the left operand after 2316 // the assignment...'. 2317 if (LHS.isBitField()) 2318 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, &RHS); 2319 else 2320 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS); 2321 } 2322 2323 // If the result is clearly ignored, return now. 2324 if (Ignore) 2325 return 0; 2326 2327 // The result of an assignment in C is the assigned r-value. 2328 if (!CGF.getContext().getLangOptions().CPlusPlus) 2329 return RHS; 2330 2331 // Objective-C property assignment never reloads the value following a store. 2332 if (LHS.isPropertyRef()) 2333 return RHS; 2334 2335 // If the lvalue is non-volatile, return the computed value of the assignment. 2336 if (!LHS.isVolatileQualified()) 2337 return RHS; 2338 2339 // Otherwise, reload the value. 2340 return EmitLoadOfLValue(LHS); 2341 } 2342 2343 Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 2344 llvm::Type *ResTy = ConvertType(E->getType()); 2345 2346 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 2347 // If we have 1 && X, just emit X without inserting the control flow. 2348 bool LHSCondVal; 2349 if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) { 2350 if (LHSCondVal) { // If we have 1 && X, just emit X. 2351 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2352 // ZExt result to int or bool. 2353 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 2354 } 2355 2356 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 2357 if (!CGF.ContainsLabel(E->getRHS())) 2358 return llvm::Constant::getNullValue(ResTy); 2359 } 2360 2361 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 2362 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 2363 2364 CodeGenFunction::ConditionalEvaluation eval(CGF); 2365 2366 // Branch on the LHS first. If it is false, go to the failure (cont) block. 2367 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 2368 2369 // Any edges into the ContBlock are now from an (indeterminate number of) 2370 // edges from this first condition. All of these values will be false. Start 2371 // setting up the PHI node in the Cont Block for this. 2372 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2, 2373 "", ContBlock); 2374 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 2375 PI != PE; ++PI) 2376 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 2377 2378 eval.begin(CGF); 2379 CGF.EmitBlock(RHSBlock); 2380 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2381 eval.end(CGF); 2382 2383 // Reaquire the RHS block, as there may be subblocks inserted. 2384 RHSBlock = Builder.GetInsertBlock(); 2385 2386 // Emit an unconditional branch from this block to ContBlock. Insert an entry 2387 // into the phi node for the edge with the value of RHSCond. 2388 if (CGF.getDebugInfo()) 2389 // There is no need to emit line number for unconditional branch. 2390 Builder.SetCurrentDebugLocation(llvm::DebugLoc()); 2391 CGF.EmitBlock(ContBlock); 2392 PN->addIncoming(RHSCond, RHSBlock); 2393 2394 // ZExt result to int. 2395 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); 2396 } 2397 2398 Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 2399 llvm::Type *ResTy = ConvertType(E->getType()); 2400 2401 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 2402 // If we have 0 || X, just emit X without inserting the control flow. 2403 bool LHSCondVal; 2404 if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) { 2405 if (!LHSCondVal) { // If we have 0 || X, just emit X. 2406 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2407 // ZExt result to int or bool. 2408 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 2409 } 2410 2411 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 2412 if (!CGF.ContainsLabel(E->getRHS())) 2413 return llvm::ConstantInt::get(ResTy, 1); 2414 } 2415 2416 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 2417 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 2418 2419 CodeGenFunction::ConditionalEvaluation eval(CGF); 2420 2421 // Branch on the LHS first. If it is true, go to the success (cont) block. 2422 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 2423 2424 // Any edges into the ContBlock are now from an (indeterminate number of) 2425 // edges from this first condition. All of these values will be true. Start 2426 // setting up the PHI node in the Cont Block for this. 2427 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2, 2428 "", ContBlock); 2429 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 2430 PI != PE; ++PI) 2431 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 2432 2433 eval.begin(CGF); 2434 2435 // Emit the RHS condition as a bool value. 2436 CGF.EmitBlock(RHSBlock); 2437 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2438 2439 eval.end(CGF); 2440 2441 // Reaquire the RHS block, as there may be subblocks inserted. 2442 RHSBlock = Builder.GetInsertBlock(); 2443 2444 // Emit an unconditional branch from this block to ContBlock. Insert an entry 2445 // into the phi node for the edge with the value of RHSCond. 2446 CGF.EmitBlock(ContBlock); 2447 PN->addIncoming(RHSCond, RHSBlock); 2448 2449 // ZExt result to int. 2450 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 2451 } 2452 2453 Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 2454 CGF.EmitIgnoredExpr(E->getLHS()); 2455 CGF.EnsureInsertPoint(); 2456 return Visit(E->getRHS()); 2457 } 2458 2459 //===----------------------------------------------------------------------===// 2460 // Other Operators 2461 //===----------------------------------------------------------------------===// 2462 2463 /// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 2464 /// expression is cheap enough and side-effect-free enough to evaluate 2465 /// unconditionally instead of conditionally. This is used to convert control 2466 /// flow into selects in some cases. 2467 static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 2468 CodeGenFunction &CGF) { 2469 E = E->IgnoreParens(); 2470 2471 // Anything that is an integer or floating point constant is fine. 2472 if (E->isConstantInitializer(CGF.getContext(), false)) 2473 return true; 2474 2475 // Non-volatile automatic variables too, to get "cond ? X : Y" where 2476 // X and Y are local variables. 2477 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 2478 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 2479 if (VD->hasLocalStorage() && !(CGF.getContext() 2480 .getCanonicalType(VD->getType()) 2481 .isVolatileQualified())) 2482 return true; 2483 2484 return false; 2485 } 2486 2487 2488 Value *ScalarExprEmitter:: 2489 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) { 2490 TestAndClearIgnoreResultAssign(); 2491 2492 // Bind the common expression if necessary. 2493 CodeGenFunction::OpaqueValueMapping binding(CGF, E); 2494 2495 Expr *condExpr = E->getCond(); 2496 Expr *lhsExpr = E->getTrueExpr(); 2497 Expr *rhsExpr = E->getFalseExpr(); 2498 2499 // If the condition constant folds and can be elided, try to avoid emitting 2500 // the condition and the dead arm. 2501 bool CondExprBool; 2502 if (CGF.ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) { 2503 Expr *live = lhsExpr, *dead = rhsExpr; 2504 if (!CondExprBool) std::swap(live, dead); 2505 2506 // If the dead side doesn't have labels we need, just emit the Live part. 2507 if (!CGF.ContainsLabel(dead)) { 2508 Value *Result = Visit(live); 2509 2510 // If the live part is a throw expression, it acts like it has a void 2511 // type, so evaluating it returns a null Value*. However, a conditional 2512 // with non-void type must return a non-null Value*. 2513 if (!Result && !E->getType()->isVoidType()) 2514 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType())); 2515 2516 return Result; 2517 } 2518 } 2519 2520 // OpenCL: If the condition is a vector, we can treat this condition like 2521 // the select function. 2522 if (CGF.getContext().getLangOptions().OpenCL 2523 && condExpr->getType()->isVectorType()) { 2524 llvm::Value *CondV = CGF.EmitScalarExpr(condExpr); 2525 llvm::Value *LHS = Visit(lhsExpr); 2526 llvm::Value *RHS = Visit(rhsExpr); 2527 2528 llvm::Type *condType = ConvertType(condExpr->getType()); 2529 llvm::VectorType *vecTy = cast<llvm::VectorType>(condType); 2530 2531 unsigned numElem = vecTy->getNumElements(); 2532 llvm::Type *elemType = vecTy->getElementType(); 2533 2534 std::vector<llvm::Constant*> Zvals; 2535 for (unsigned i = 0; i < numElem; ++i) 2536 Zvals.push_back(llvm::ConstantInt::get(elemType, 0)); 2537 2538 llvm::Value *zeroVec = llvm::ConstantVector::get(Zvals); 2539 llvm::Value *TestMSB = Builder.CreateICmpSLT(CondV, zeroVec); 2540 llvm::Value *tmp = Builder.CreateSExt(TestMSB, 2541 llvm::VectorType::get(elemType, 2542 numElem), 2543 "sext"); 2544 llvm::Value *tmp2 = Builder.CreateNot(tmp); 2545 2546 // Cast float to int to perform ANDs if necessary. 2547 llvm::Value *RHSTmp = RHS; 2548 llvm::Value *LHSTmp = LHS; 2549 bool wasCast = false; 2550 llvm::VectorType *rhsVTy = cast<llvm::VectorType>(RHS->getType()); 2551 if (rhsVTy->getElementType()->isFloatTy()) { 2552 RHSTmp = Builder.CreateBitCast(RHS, tmp2->getType()); 2553 LHSTmp = Builder.CreateBitCast(LHS, tmp->getType()); 2554 wasCast = true; 2555 } 2556 2557 llvm::Value *tmp3 = Builder.CreateAnd(RHSTmp, tmp2); 2558 llvm::Value *tmp4 = Builder.CreateAnd(LHSTmp, tmp); 2559 llvm::Value *tmp5 = Builder.CreateOr(tmp3, tmp4, "cond"); 2560 if (wasCast) 2561 tmp5 = Builder.CreateBitCast(tmp5, RHS->getType()); 2562 2563 return tmp5; 2564 } 2565 2566 // If this is a really simple expression (like x ? 4 : 5), emit this as a 2567 // select instead of as control flow. We can only do this if it is cheap and 2568 // safe to evaluate the LHS and RHS unconditionally. 2569 if (isCheapEnoughToEvaluateUnconditionally(lhsExpr, CGF) && 2570 isCheapEnoughToEvaluateUnconditionally(rhsExpr, CGF)) { 2571 llvm::Value *CondV = CGF.EvaluateExprAsBool(condExpr); 2572 llvm::Value *LHS = Visit(lhsExpr); 2573 llvm::Value *RHS = Visit(rhsExpr); 2574 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 2575 } 2576 2577 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 2578 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 2579 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 2580 2581 CodeGenFunction::ConditionalEvaluation eval(CGF); 2582 CGF.EmitBranchOnBoolExpr(condExpr, LHSBlock, RHSBlock); 2583 2584 CGF.EmitBlock(LHSBlock); 2585 eval.begin(CGF); 2586 Value *LHS = Visit(lhsExpr); 2587 eval.end(CGF); 2588 2589 LHSBlock = Builder.GetInsertBlock(); 2590 Builder.CreateBr(ContBlock); 2591 2592 CGF.EmitBlock(RHSBlock); 2593 eval.begin(CGF); 2594 Value *RHS = Visit(rhsExpr); 2595 eval.end(CGF); 2596 2597 RHSBlock = Builder.GetInsertBlock(); 2598 CGF.EmitBlock(ContBlock); 2599 2600 // If the LHS or RHS is a throw expression, it will be legitimately null. 2601 if (!LHS) 2602 return RHS; 2603 if (!RHS) 2604 return LHS; 2605 2606 // Create a PHI node for the real part. 2607 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), 2, "cond"); 2608 PN->addIncoming(LHS, LHSBlock); 2609 PN->addIncoming(RHS, RHSBlock); 2610 return PN; 2611 } 2612 2613 Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 2614 return Visit(E->getChosenSubExpr(CGF.getContext())); 2615 } 2616 2617 Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 2618 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 2619 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 2620 2621 // If EmitVAArg fails, we fall back to the LLVM instruction. 2622 if (!ArgPtr) 2623 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 2624 2625 // FIXME Volatility. 2626 return Builder.CreateLoad(ArgPtr); 2627 } 2628 2629 Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *block) { 2630 return CGF.EmitBlockLiteral(block); 2631 } 2632 2633 Value *ScalarExprEmitter::VisitAsTypeExpr(AsTypeExpr *E) { 2634 Value *Src = CGF.EmitScalarExpr(E->getSrcExpr()); 2635 llvm::Type *DstTy = ConvertType(E->getType()); 2636 2637 // Going from vec4->vec3 or vec3->vec4 is a special case and requires 2638 // a shuffle vector instead of a bitcast. 2639 llvm::Type *SrcTy = Src->getType(); 2640 if (isa<llvm::VectorType>(DstTy) && isa<llvm::VectorType>(SrcTy)) { 2641 unsigned numElementsDst = cast<llvm::VectorType>(DstTy)->getNumElements(); 2642 unsigned numElementsSrc = cast<llvm::VectorType>(SrcTy)->getNumElements(); 2643 if ((numElementsDst == 3 && numElementsSrc == 4) 2644 || (numElementsDst == 4 && numElementsSrc == 3)) { 2645 2646 2647 // In the case of going from int4->float3, a bitcast is needed before 2648 // doing a shuffle. 2649 llvm::Type *srcElemTy = 2650 cast<llvm::VectorType>(SrcTy)->getElementType(); 2651 llvm::Type *dstElemTy = 2652 cast<llvm::VectorType>(DstTy)->getElementType(); 2653 2654 if ((srcElemTy->isIntegerTy() && dstElemTy->isFloatTy()) 2655 || (srcElemTy->isFloatTy() && dstElemTy->isIntegerTy())) { 2656 // Create a float type of the same size as the source or destination. 2657 llvm::VectorType *newSrcTy = llvm::VectorType::get(dstElemTy, 2658 numElementsSrc); 2659 2660 Src = Builder.CreateBitCast(Src, newSrcTy, "astypeCast"); 2661 } 2662 2663 llvm::Value *UnV = llvm::UndefValue::get(Src->getType()); 2664 2665 SmallVector<llvm::Constant*, 3> Args; 2666 Args.push_back(Builder.getInt32(0)); 2667 Args.push_back(Builder.getInt32(1)); 2668 Args.push_back(Builder.getInt32(2)); 2669 2670 if (numElementsDst == 4) 2671 Args.push_back(llvm::UndefValue::get( 2672 llvm::Type::getInt32Ty(CGF.getLLVMContext()))); 2673 2674 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 2675 2676 return Builder.CreateShuffleVector(Src, UnV, Mask, "astype"); 2677 } 2678 } 2679 2680 return Builder.CreateBitCast(Src, DstTy, "astype"); 2681 } 2682 2683 Value *ScalarExprEmitter::VisitAtomicExpr(AtomicExpr *E) { 2684 return CGF.EmitAtomicExpr(E).getScalarVal(); 2685 } 2686 2687 //===----------------------------------------------------------------------===// 2688 // Entry Point into this File 2689 //===----------------------------------------------------------------------===// 2690 2691 /// EmitScalarExpr - Emit the computation of the specified expression of scalar 2692 /// type, ignoring the result. 2693 Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 2694 assert(E && !hasAggregateLLVMType(E->getType()) && 2695 "Invalid scalar expression to emit"); 2696 2697 if (isa<CXXDefaultArgExpr>(E)) 2698 disableDebugInfo(); 2699 Value *V = ScalarExprEmitter(*this, IgnoreResultAssign) 2700 .Visit(const_cast<Expr*>(E)); 2701 if (isa<CXXDefaultArgExpr>(E)) 2702 enableDebugInfo(); 2703 return V; 2704 } 2705 2706 /// EmitScalarConversion - Emit a conversion from the specified type to the 2707 /// specified destination type, both of which are LLVM scalar types. 2708 Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 2709 QualType DstTy) { 2710 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 2711 "Invalid scalar expression to emit"); 2712 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 2713 } 2714 2715 /// EmitComplexToScalarConversion - Emit a conversion from the specified complex 2716 /// type to the specified destination type, where the destination type is an 2717 /// LLVM scalar type. 2718 Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 2719 QualType SrcTy, 2720 QualType DstTy) { 2721 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 2722 "Invalid complex -> scalar conversion"); 2723 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 2724 DstTy); 2725 } 2726 2727 2728 llvm::Value *CodeGenFunction:: 2729 EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 2730 bool isInc, bool isPre) { 2731 return ScalarExprEmitter(*this).EmitScalarPrePostIncDec(E, LV, isInc, isPre); 2732 } 2733 2734 LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) { 2735 llvm::Value *V; 2736 // object->isa or (*object).isa 2737 // Generate code as for: *(Class*)object 2738 // build Class* type 2739 llvm::Type *ClassPtrTy = ConvertType(E->getType()); 2740 2741 Expr *BaseExpr = E->getBase(); 2742 if (BaseExpr->isRValue()) { 2743 V = CreateTempAlloca(ClassPtrTy, "resval"); 2744 llvm::Value *Src = EmitScalarExpr(BaseExpr); 2745 Builder.CreateStore(Src, V); 2746 V = ScalarExprEmitter(*this).EmitLoadOfLValue( 2747 MakeAddrLValue(V, E->getType())); 2748 } else { 2749 if (E->isArrow()) 2750 V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr); 2751 else 2752 V = EmitLValue(BaseExpr).getAddress(); 2753 } 2754 2755 // build Class* type 2756 ClassPtrTy = ClassPtrTy->getPointerTo(); 2757 V = Builder.CreateBitCast(V, ClassPtrTy); 2758 return MakeAddrLValue(V, E->getType()); 2759 } 2760 2761 2762 LValue CodeGenFunction::EmitCompoundAssignmentLValue( 2763 const CompoundAssignOperator *E) { 2764 ScalarExprEmitter Scalar(*this); 2765 Value *Result = 0; 2766 switch (E->getOpcode()) { 2767 #define COMPOUND_OP(Op) \ 2768 case BO_##Op##Assign: \ 2769 return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \ 2770 Result) 2771 COMPOUND_OP(Mul); 2772 COMPOUND_OP(Div); 2773 COMPOUND_OP(Rem); 2774 COMPOUND_OP(Add); 2775 COMPOUND_OP(Sub); 2776 COMPOUND_OP(Shl); 2777 COMPOUND_OP(Shr); 2778 COMPOUND_OP(And); 2779 COMPOUND_OP(Xor); 2780 COMPOUND_OP(Or); 2781 #undef COMPOUND_OP 2782 2783 case BO_PtrMemD: 2784 case BO_PtrMemI: 2785 case BO_Mul: 2786 case BO_Div: 2787 case BO_Rem: 2788 case BO_Add: 2789 case BO_Sub: 2790 case BO_Shl: 2791 case BO_Shr: 2792 case BO_LT: 2793 case BO_GT: 2794 case BO_LE: 2795 case BO_GE: 2796 case BO_EQ: 2797 case BO_NE: 2798 case BO_And: 2799 case BO_Xor: 2800 case BO_Or: 2801 case BO_LAnd: 2802 case BO_LOr: 2803 case BO_Assign: 2804 case BO_Comma: 2805 llvm_unreachable("Not valid compound assignment operators"); 2806 } 2807 2808 llvm_unreachable("Unhandled compound assignment operator"); 2809 } 2810