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, CodeGenFunction::TypeCheckKind TCK) { 84 return CGF.EmitCheckedLValue(E, TCK); 85 } 86 87 Value *EmitLoadOfLValue(LValue LV) { 88 return CGF.EmitLoadOfLValue(LV).getScalarVal(); 89 } 90 91 /// EmitLoadOfLValue - Given an expression with complex type that represents a 92 /// value l-value, this method emits the address of the l-value, then loads 93 /// and returns the result. 94 Value *EmitLoadOfLValue(const Expr *E) { 95 return EmitLoadOfLValue(EmitCheckedLValue(E, CodeGenFunction::TCK_Load)); 96 } 97 98 /// EmitConversionToBool - Convert the specified expression value to a 99 /// boolean (i1) truth value. This is equivalent to "Val != 0". 100 Value *EmitConversionToBool(Value *Src, QualType DstTy); 101 102 /// EmitScalarConversion - Emit a conversion from the specified type to the 103 /// specified destination type, both of which are LLVM scalar types. 104 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); 105 106 /// EmitComplexToScalarConversion - Emit a conversion from the specified 107 /// complex type to the specified destination type, where the destination type 108 /// is an LLVM scalar type. 109 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 110 QualType SrcTy, QualType DstTy); 111 112 /// EmitNullValue - Emit a value that corresponds to null for the given type. 113 Value *EmitNullValue(QualType Ty); 114 115 /// EmitFloatToBoolConversion - Perform an FP to boolean conversion. 116 Value *EmitFloatToBoolConversion(Value *V) { 117 // Compare against 0.0 for fp scalars. 118 llvm::Value *Zero = llvm::Constant::getNullValue(V->getType()); 119 return Builder.CreateFCmpUNE(V, Zero, "tobool"); 120 } 121 122 /// EmitPointerToBoolConversion - Perform a pointer to boolean conversion. 123 Value *EmitPointerToBoolConversion(Value *V) { 124 Value *Zero = llvm::ConstantPointerNull::get( 125 cast<llvm::PointerType>(V->getType())); 126 return Builder.CreateICmpNE(V, Zero, "tobool"); 127 } 128 129 Value *EmitIntToBoolConversion(Value *V) { 130 // Because of the type rules of C, we often end up computing a 131 // logical value, then zero extending it to int, then wanting it 132 // as a logical value again. Optimize this common case. 133 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(V)) { 134 if (ZI->getOperand(0)->getType() == Builder.getInt1Ty()) { 135 Value *Result = ZI->getOperand(0); 136 // If there aren't any more uses, zap the instruction to save space. 137 // Note that there can be more uses, for example if this 138 // is the result of an assignment. 139 if (ZI->use_empty()) 140 ZI->eraseFromParent(); 141 return Result; 142 } 143 } 144 145 return Builder.CreateIsNotNull(V, "tobool"); 146 } 147 148 //===--------------------------------------------------------------------===// 149 // Visitor Methods 150 //===--------------------------------------------------------------------===// 151 152 Value *Visit(Expr *E) { 153 return StmtVisitor<ScalarExprEmitter, Value*>::Visit(E); 154 } 155 156 Value *VisitStmt(Stmt *S) { 157 S->dump(CGF.getContext().getSourceManager()); 158 llvm_unreachable("Stmt can't have complex result type!"); 159 } 160 Value *VisitExpr(Expr *S); 161 162 Value *VisitParenExpr(ParenExpr *PE) { 163 return Visit(PE->getSubExpr()); 164 } 165 Value *VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) { 166 return Visit(E->getReplacement()); 167 } 168 Value *VisitGenericSelectionExpr(GenericSelectionExpr *GE) { 169 return Visit(GE->getResultExpr()); 170 } 171 172 // Leaves. 173 Value *VisitIntegerLiteral(const IntegerLiteral *E) { 174 return Builder.getInt(E->getValue()); 175 } 176 Value *VisitFloatingLiteral(const FloatingLiteral *E) { 177 return llvm::ConstantFP::get(VMContext, E->getValue()); 178 } 179 Value *VisitCharacterLiteral(const CharacterLiteral *E) { 180 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 181 } 182 Value *VisitObjCBoolLiteralExpr(const ObjCBoolLiteralExpr *E) { 183 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 184 } 185 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 186 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 187 } 188 Value *VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) { 189 return EmitNullValue(E->getType()); 190 } 191 Value *VisitGNUNullExpr(const GNUNullExpr *E) { 192 return EmitNullValue(E->getType()); 193 } 194 Value *VisitOffsetOfExpr(OffsetOfExpr *E); 195 Value *VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E); 196 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 197 llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel()); 198 return Builder.CreateBitCast(V, ConvertType(E->getType())); 199 } 200 201 Value *VisitSizeOfPackExpr(SizeOfPackExpr *E) { 202 return llvm::ConstantInt::get(ConvertType(E->getType()),E->getPackLength()); 203 } 204 205 Value *VisitPseudoObjectExpr(PseudoObjectExpr *E) { 206 return CGF.EmitPseudoObjectRValue(E).getScalarVal(); 207 } 208 209 Value *VisitOpaqueValueExpr(OpaqueValueExpr *E) { 210 if (E->isGLValue()) 211 return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E)); 212 213 // Otherwise, assume the mapping is the scalar directly. 214 return CGF.getOpaqueRValueMapping(E).getScalarVal(); 215 } 216 217 // l-values. 218 Value *VisitDeclRefExpr(DeclRefExpr *E) { 219 if (CodeGenFunction::ConstantEmission result = CGF.tryEmitAsConstant(E)) { 220 if (result.isReference()) 221 return EmitLoadOfLValue(result.getReferenceLValue(CGF, E)); 222 return result.getValue(); 223 } 224 return EmitLoadOfLValue(E); 225 } 226 227 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 228 return CGF.EmitObjCSelectorExpr(E); 229 } 230 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 231 return CGF.EmitObjCProtocolExpr(E); 232 } 233 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 234 return EmitLoadOfLValue(E); 235 } 236 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 237 if (E->getMethodDecl() && 238 E->getMethodDecl()->getResultType()->isReferenceType()) 239 return EmitLoadOfLValue(E); 240 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 241 } 242 243 Value *VisitObjCIsaExpr(ObjCIsaExpr *E) { 244 LValue LV = CGF.EmitObjCIsaExpr(E); 245 Value *V = CGF.EmitLoadOfLValue(LV).getScalarVal(); 246 return V; 247 } 248 249 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 250 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 251 Value *VisitMemberExpr(MemberExpr *E); 252 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 253 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 254 return EmitLoadOfLValue(E); 255 } 256 257 Value *VisitInitListExpr(InitListExpr *E); 258 259 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { 260 return CGF.CGM.EmitNullConstant(E->getType()); 261 } 262 Value *VisitExplicitCastExpr(ExplicitCastExpr *E) { 263 if (E->getType()->isVariablyModifiedType()) 264 CGF.EmitVariablyModifiedType(E->getType()); 265 return VisitCastExpr(E); 266 } 267 Value *VisitCastExpr(CastExpr *E); 268 269 Value *VisitCallExpr(const CallExpr *E) { 270 if (E->getCallReturnType()->isReferenceType()) 271 return EmitLoadOfLValue(E); 272 273 return CGF.EmitCallExpr(E).getScalarVal(); 274 } 275 276 Value *VisitStmtExpr(const StmtExpr *E); 277 278 // Unary Operators. 279 Value *VisitUnaryPostDec(const UnaryOperator *E) { 280 LValue LV = EmitLValue(E->getSubExpr()); 281 return EmitScalarPrePostIncDec(E, LV, false, false); 282 } 283 Value *VisitUnaryPostInc(const UnaryOperator *E) { 284 LValue LV = EmitLValue(E->getSubExpr()); 285 return EmitScalarPrePostIncDec(E, LV, true, false); 286 } 287 Value *VisitUnaryPreDec(const UnaryOperator *E) { 288 LValue LV = EmitLValue(E->getSubExpr()); 289 return EmitScalarPrePostIncDec(E, LV, false, true); 290 } 291 Value *VisitUnaryPreInc(const UnaryOperator *E) { 292 LValue LV = EmitLValue(E->getSubExpr()); 293 return EmitScalarPrePostIncDec(E, LV, true, true); 294 } 295 296 llvm::Value *EmitAddConsiderOverflowBehavior(const UnaryOperator *E, 297 llvm::Value *InVal, 298 llvm::Value *NextVal, 299 bool IsInc); 300 301 llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 302 bool isInc, bool isPre); 303 304 305 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 306 if (isa<MemberPointerType>(E->getType())) // never sugared 307 return CGF.CGM.getMemberPointerConstant(E); 308 309 return EmitLValue(E->getSubExpr()).getAddress(); 310 } 311 Value *VisitUnaryDeref(const UnaryOperator *E) { 312 if (E->getType()->isVoidType()) 313 return Visit(E->getSubExpr()); // the actual value should be unused 314 return EmitLoadOfLValue(E); 315 } 316 Value *VisitUnaryPlus(const UnaryOperator *E) { 317 // This differs from gcc, though, most likely due to a bug in gcc. 318 TestAndClearIgnoreResultAssign(); 319 return Visit(E->getSubExpr()); 320 } 321 Value *VisitUnaryMinus (const UnaryOperator *E); 322 Value *VisitUnaryNot (const UnaryOperator *E); 323 Value *VisitUnaryLNot (const UnaryOperator *E); 324 Value *VisitUnaryReal (const UnaryOperator *E); 325 Value *VisitUnaryImag (const UnaryOperator *E); 326 Value *VisitUnaryExtension(const UnaryOperator *E) { 327 return Visit(E->getSubExpr()); 328 } 329 330 // C++ 331 Value *VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E) { 332 return EmitLoadOfLValue(E); 333 } 334 335 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 336 return Visit(DAE->getExpr()); 337 } 338 Value *VisitCXXThisExpr(CXXThisExpr *TE) { 339 return CGF.LoadCXXThis(); 340 } 341 342 Value *VisitExprWithCleanups(ExprWithCleanups *E) { 343 CGF.enterFullExpression(E); 344 CodeGenFunction::RunCleanupsScope Scope(CGF); 345 return Visit(E->getSubExpr()); 346 } 347 Value *VisitCXXNewExpr(const CXXNewExpr *E) { 348 return CGF.EmitCXXNewExpr(E); 349 } 350 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { 351 CGF.EmitCXXDeleteExpr(E); 352 return 0; 353 } 354 Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) { 355 return Builder.getInt1(E->getValue()); 356 } 357 358 Value *VisitBinaryTypeTraitExpr(const BinaryTypeTraitExpr *E) { 359 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 360 } 361 362 Value *VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) { 363 return llvm::ConstantInt::get(Builder.getInt32Ty(), E->getValue()); 364 } 365 366 Value *VisitExpressionTraitExpr(const ExpressionTraitExpr *E) { 367 return llvm::ConstantInt::get(Builder.getInt1Ty(), E->getValue()); 368 } 369 370 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { 371 // C++ [expr.pseudo]p1: 372 // The result shall only be used as the operand for the function call 373 // operator (), and the result of such a call has type void. The only 374 // effect is the evaluation of the postfix-expression before the dot or 375 // arrow. 376 CGF.EmitScalarExpr(E->getBase()); 377 return 0; 378 } 379 380 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { 381 return EmitNullValue(E->getType()); 382 } 383 384 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { 385 CGF.EmitCXXThrowExpr(E); 386 return 0; 387 } 388 389 Value *VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) { 390 return Builder.getInt1(E->getValue()); 391 } 392 393 // Binary Operators. 394 Value *EmitMul(const BinOpInfo &Ops) { 395 if (Ops.Ty->isSignedIntegerOrEnumerationType()) { 396 switch (CGF.getContext().getLangOpts().getSignedOverflowBehavior()) { 397 case LangOptions::SOB_Defined: 398 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 399 case LangOptions::SOB_Undefined: 400 if (!CGF.CatchUndefined) 401 return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul"); 402 // Fall through. 403 case LangOptions::SOB_Trapping: 404 return EmitOverflowCheckedBinOp(Ops); 405 } 406 } 407 408 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 409 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 410 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 411 } 412 bool isTrapvOverflowBehavior() { 413 return CGF.getContext().getLangOpts().getSignedOverflowBehavior() 414 == LangOptions::SOB_Trapping || CGF.CatchUndefined; 415 } 416 /// Create a binary op that checks for overflow. 417 /// Currently only supports +, - and *. 418 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 419 420 // Check for undefined division and modulus behaviors. 421 void EmitUndefinedBehaviorIntegerDivAndRemCheck(const BinOpInfo &Ops, 422 llvm::Value *Zero,bool isDiv); 423 Value *EmitDiv(const BinOpInfo &Ops); 424 Value *EmitRem(const BinOpInfo &Ops); 425 Value *EmitAdd(const BinOpInfo &Ops); 426 Value *EmitSub(const BinOpInfo &Ops); 427 Value *EmitShl(const BinOpInfo &Ops); 428 Value *EmitShr(const BinOpInfo &Ops); 429 Value *EmitAnd(const BinOpInfo &Ops) { 430 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 431 } 432 Value *EmitXor(const BinOpInfo &Ops) { 433 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 434 } 435 Value *EmitOr (const BinOpInfo &Ops) { 436 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 437 } 438 439 BinOpInfo EmitBinOps(const BinaryOperator *E); 440 LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E, 441 Value *(ScalarExprEmitter::*F)(const BinOpInfo &), 442 Value *&Result); 443 444 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 445 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 446 447 // Binary operators and binary compound assignment operators. 448 #define HANDLEBINOP(OP) \ 449 Value *VisitBin ## OP(const BinaryOperator *E) { \ 450 return Emit ## OP(EmitBinOps(E)); \ 451 } \ 452 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 453 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 454 } 455 HANDLEBINOP(Mul) 456 HANDLEBINOP(Div) 457 HANDLEBINOP(Rem) 458 HANDLEBINOP(Add) 459 HANDLEBINOP(Sub) 460 HANDLEBINOP(Shl) 461 HANDLEBINOP(Shr) 462 HANDLEBINOP(And) 463 HANDLEBINOP(Xor) 464 HANDLEBINOP(Or) 465 #undef HANDLEBINOP 466 467 // Comparisons. 468 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 469 unsigned SICmpOpc, unsigned FCmpOpc); 470 #define VISITCOMP(CODE, UI, SI, FP) \ 471 Value *VisitBin##CODE(const BinaryOperator *E) { \ 472 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 473 llvm::FCmpInst::FP); } 474 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT) 475 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT) 476 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE) 477 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE) 478 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ) 479 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE) 480 #undef VISITCOMP 481 482 Value *VisitBinAssign (const BinaryOperator *E); 483 484 Value *VisitBinLAnd (const BinaryOperator *E); 485 Value *VisitBinLOr (const BinaryOperator *E); 486 Value *VisitBinComma (const BinaryOperator *E); 487 488 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } 489 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); } 490 491 // Other Operators. 492 Value *VisitBlockExpr(const BlockExpr *BE); 493 Value *VisitAbstractConditionalOperator(const AbstractConditionalOperator *); 494 Value *VisitChooseExpr(ChooseExpr *CE); 495 Value *VisitVAArgExpr(VAArgExpr *VE); 496 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 497 return CGF.EmitObjCStringLiteral(E); 498 } 499 Value *VisitObjCBoxedExpr(ObjCBoxedExpr *E) { 500 return CGF.EmitObjCBoxedExpr(E); 501 } 502 Value *VisitObjCArrayLiteral(ObjCArrayLiteral *E) { 503 return CGF.EmitObjCArrayLiteral(E); 504 } 505 Value *VisitObjCDictionaryLiteral(ObjCDictionaryLiteral *E) { 506 return CGF.EmitObjCDictionaryLiteral(E); 507 } 508 Value *VisitAsTypeExpr(AsTypeExpr *CE); 509 Value *VisitAtomicExpr(AtomicExpr *AE); 510 }; 511 } // end anonymous namespace. 512 513 //===----------------------------------------------------------------------===// 514 // Utilities 515 //===----------------------------------------------------------------------===// 516 517 /// EmitConversionToBool - Convert the specified expression value to a 518 /// boolean (i1) truth value. This is equivalent to "Val != 0". 519 Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 520 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs"); 521 522 if (SrcType->isRealFloatingType()) 523 return EmitFloatToBoolConversion(Src); 524 525 if (const MemberPointerType *MPT = dyn_cast<MemberPointerType>(SrcType)) 526 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, Src, MPT); 527 528 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 529 "Unknown scalar type to convert"); 530 531 if (isa<llvm::IntegerType>(Src->getType())) 532 return EmitIntToBoolConversion(Src); 533 534 assert(isa<llvm::PointerType>(Src->getType())); 535 return EmitPointerToBoolConversion(Src); 536 } 537 538 /// EmitScalarConversion - Emit a conversion from the specified type to the 539 /// specified destination type, both of which are LLVM scalar types. 540 Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 541 QualType DstType) { 542 SrcType = CGF.getContext().getCanonicalType(SrcType); 543 DstType = CGF.getContext().getCanonicalType(DstType); 544 if (SrcType == DstType) return Src; 545 546 if (DstType->isVoidType()) return 0; 547 548 llvm::Type *SrcTy = Src->getType(); 549 550 // Floating casts might be a bit special: if we're doing casts to / from half 551 // FP, we should go via special intrinsics. 552 if (SrcType->isHalfType()) { 553 Src = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16), Src); 554 SrcType = CGF.getContext().FloatTy; 555 SrcTy = CGF.FloatTy; 556 } 557 558 // Handle conversions to bool first, they are special: comparisons against 0. 559 if (DstType->isBooleanType()) 560 return EmitConversionToBool(Src, SrcType); 561 562 llvm::Type *DstTy = ConvertType(DstType); 563 564 // Ignore conversions like int -> uint. 565 if (SrcTy == DstTy) 566 return Src; 567 568 // Handle pointer conversions next: pointers can only be converted to/from 569 // other pointers and integers. Check for pointer types in terms of LLVM, as 570 // some native types (like Obj-C id) may map to a pointer type. 571 if (isa<llvm::PointerType>(DstTy)) { 572 // The source value may be an integer, or a pointer. 573 if (isa<llvm::PointerType>(SrcTy)) 574 return Builder.CreateBitCast(Src, DstTy, "conv"); 575 576 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 577 // First, convert to the correct width so that we control the kind of 578 // extension. 579 llvm::Type *MiddleTy = CGF.IntPtrTy; 580 bool InputSigned = SrcType->isSignedIntegerOrEnumerationType(); 581 llvm::Value* IntResult = 582 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 583 // Then, cast to pointer. 584 return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); 585 } 586 587 if (isa<llvm::PointerType>(SrcTy)) { 588 // Must be an ptr to int cast. 589 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 590 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 591 } 592 593 // A scalar can be splatted to an extended vector of the same element type 594 if (DstType->isExtVectorType() && !SrcType->isVectorType()) { 595 // Cast the scalar to element type 596 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType(); 597 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 598 599 // Insert the element in element zero of an undef vector 600 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 601 llvm::Value *Idx = Builder.getInt32(0); 602 UnV = Builder.CreateInsertElement(UnV, Elt, Idx); 603 604 // Splat the element across to all elements 605 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 606 llvm::Constant *Mask = llvm::ConstantVector::getSplat(NumElements, 607 Builder.getInt32(0)); 608 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 609 return Yay; 610 } 611 612 // Allow bitcast from vector to integer/fp of the same size. 613 if (isa<llvm::VectorType>(SrcTy) || 614 isa<llvm::VectorType>(DstTy)) 615 return Builder.CreateBitCast(Src, DstTy, "conv"); 616 617 // Finally, we have the arithmetic types: real int/float. 618 Value *Res = NULL; 619 llvm::Type *ResTy = DstTy; 620 621 // Cast to half via float 622 if (DstType->isHalfType()) 623 DstTy = CGF.FloatTy; 624 625 if (isa<llvm::IntegerType>(SrcTy)) { 626 bool InputSigned = SrcType->isSignedIntegerOrEnumerationType(); 627 if (isa<llvm::IntegerType>(DstTy)) 628 Res = Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 629 else if (InputSigned) 630 Res = Builder.CreateSIToFP(Src, DstTy, "conv"); 631 else 632 Res = Builder.CreateUIToFP(Src, DstTy, "conv"); 633 } else if (isa<llvm::IntegerType>(DstTy)) { 634 assert(SrcTy->isFloatingPointTy() && "Unknown real conversion"); 635 if (DstType->isSignedIntegerOrEnumerationType()) 636 Res = Builder.CreateFPToSI(Src, DstTy, "conv"); 637 else 638 Res = Builder.CreateFPToUI(Src, DstTy, "conv"); 639 } else { 640 assert(SrcTy->isFloatingPointTy() && DstTy->isFloatingPointTy() && 641 "Unknown real conversion"); 642 if (DstTy->getTypeID() < SrcTy->getTypeID()) 643 Res = Builder.CreateFPTrunc(Src, DstTy, "conv"); 644 else 645 Res = Builder.CreateFPExt(Src, DstTy, "conv"); 646 } 647 648 if (DstTy != ResTy) { 649 assert(ResTy->isIntegerTy(16) && "Only half FP requires extra conversion"); 650 Res = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16), Res); 651 } 652 653 return Res; 654 } 655 656 /// EmitComplexToScalarConversion - Emit a conversion from the specified complex 657 /// type to the specified destination type, where the destination type is an 658 /// LLVM scalar type. 659 Value *ScalarExprEmitter:: 660 EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 661 QualType SrcTy, QualType DstTy) { 662 // Get the source element type. 663 SrcTy = SrcTy->getAs<ComplexType>()->getElementType(); 664 665 // Handle conversions to bool first, they are special: comparisons against 0. 666 if (DstTy->isBooleanType()) { 667 // Complex != 0 -> (Real != 0) | (Imag != 0) 668 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 669 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 670 return Builder.CreateOr(Src.first, Src.second, "tobool"); 671 } 672 673 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 674 // the imaginary part of the complex value is discarded and the value of the 675 // real part is converted according to the conversion rules for the 676 // corresponding real type. 677 return EmitScalarConversion(Src.first, SrcTy, DstTy); 678 } 679 680 Value *ScalarExprEmitter::EmitNullValue(QualType Ty) { 681 if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>()) 682 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 683 684 return llvm::Constant::getNullValue(ConvertType(Ty)); 685 } 686 687 //===----------------------------------------------------------------------===// 688 // Visitor Methods 689 //===----------------------------------------------------------------------===// 690 691 Value *ScalarExprEmitter::VisitExpr(Expr *E) { 692 CGF.ErrorUnsupported(E, "scalar expression"); 693 if (E->getType()->isVoidType()) 694 return 0; 695 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 696 } 697 698 Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 699 // Vector Mask Case 700 if (E->getNumSubExprs() == 2 || 701 (E->getNumSubExprs() == 3 && E->getExpr(2)->getType()->isVectorType())) { 702 Value *LHS = CGF.EmitScalarExpr(E->getExpr(0)); 703 Value *RHS = CGF.EmitScalarExpr(E->getExpr(1)); 704 Value *Mask; 705 706 llvm::VectorType *LTy = cast<llvm::VectorType>(LHS->getType()); 707 unsigned LHSElts = LTy->getNumElements(); 708 709 if (E->getNumSubExprs() == 3) { 710 Mask = CGF.EmitScalarExpr(E->getExpr(2)); 711 712 // Shuffle LHS & RHS into one input vector. 713 SmallVector<llvm::Constant*, 32> concat; 714 for (unsigned i = 0; i != LHSElts; ++i) { 715 concat.push_back(Builder.getInt32(2*i)); 716 concat.push_back(Builder.getInt32(2*i+1)); 717 } 718 719 Value* CV = llvm::ConstantVector::get(concat); 720 LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat"); 721 LHSElts *= 2; 722 } else { 723 Mask = RHS; 724 } 725 726 llvm::VectorType *MTy = cast<llvm::VectorType>(Mask->getType()); 727 llvm::Constant* EltMask; 728 729 // Treat vec3 like vec4. 730 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) 731 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 732 (1 << llvm::Log2_32(LHSElts+2))-1); 733 else if ((LHSElts == 3) && (E->getNumSubExprs() == 2)) 734 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 735 (1 << llvm::Log2_32(LHSElts+1))-1); 736 else 737 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 738 (1 << llvm::Log2_32(LHSElts))-1); 739 740 // Mask off the high bits of each shuffle index. 741 Value *MaskBits = llvm::ConstantVector::getSplat(MTy->getNumElements(), 742 EltMask); 743 Mask = Builder.CreateAnd(Mask, MaskBits, "mask"); 744 745 // newv = undef 746 // mask = mask & maskbits 747 // for each elt 748 // n = extract mask i 749 // x = extract val n 750 // newv = insert newv, x, i 751 llvm::VectorType *RTy = llvm::VectorType::get(LTy->getElementType(), 752 MTy->getNumElements()); 753 Value* NewV = llvm::UndefValue::get(RTy); 754 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) { 755 Value *IIndx = Builder.getInt32(i); 756 Value *Indx = Builder.CreateExtractElement(Mask, IIndx, "shuf_idx"); 757 Indx = Builder.CreateZExt(Indx, CGF.Int32Ty, "idx_zext"); 758 759 // Handle vec3 special since the index will be off by one for the RHS. 760 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) { 761 Value *cmpIndx, *newIndx; 762 cmpIndx = Builder.CreateICmpUGT(Indx, Builder.getInt32(3), 763 "cmp_shuf_idx"); 764 newIndx = Builder.CreateSub(Indx, Builder.getInt32(1), "shuf_idx_adj"); 765 Indx = Builder.CreateSelect(cmpIndx, newIndx, Indx, "sel_shuf_idx"); 766 } 767 Value *VExt = Builder.CreateExtractElement(LHS, Indx, "shuf_elt"); 768 NewV = Builder.CreateInsertElement(NewV, VExt, IIndx, "shuf_ins"); 769 } 770 return NewV; 771 } 772 773 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 774 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 775 776 // Handle vec3 special since the index will be off by one for the RHS. 777 llvm::VectorType *VTy = cast<llvm::VectorType>(V1->getType()); 778 SmallVector<llvm::Constant*, 32> indices; 779 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 780 unsigned Idx = E->getShuffleMaskIdx(CGF.getContext(), i-2); 781 if (VTy->getNumElements() == 3 && Idx > 3) 782 Idx -= 1; 783 indices.push_back(Builder.getInt32(Idx)); 784 } 785 786 Value *SV = llvm::ConstantVector::get(indices); 787 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 788 } 789 Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { 790 llvm::APSInt Value; 791 if (E->EvaluateAsInt(Value, CGF.getContext(), Expr::SE_AllowSideEffects)) { 792 if (E->isArrow()) 793 CGF.EmitScalarExpr(E->getBase()); 794 else 795 EmitLValue(E->getBase()); 796 return Builder.getInt(Value); 797 } 798 799 // Emit debug info for aggregate now, if it was delayed to reduce 800 // debug info size. 801 CGDebugInfo *DI = CGF.getDebugInfo(); 802 if (DI && 803 CGF.CGM.getCodeGenOpts().DebugInfo == CodeGenOptions::LimitedDebugInfo) { 804 QualType PQTy = E->getBase()->IgnoreParenImpCasts()->getType(); 805 if (const PointerType * PTy = dyn_cast<PointerType>(PQTy)) 806 if (FieldDecl *M = dyn_cast<FieldDecl>(E->getMemberDecl())) 807 DI->getOrCreateRecordType(PTy->getPointeeType(), 808 M->getParent()->getLocation()); 809 } 810 return EmitLoadOfLValue(E); 811 } 812 813 Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 814 TestAndClearIgnoreResultAssign(); 815 816 // Emit subscript expressions in rvalue context's. For most cases, this just 817 // loads the lvalue formed by the subscript expr. However, we have to be 818 // careful, because the base of a vector subscript is occasionally an rvalue, 819 // so we can't get it as an lvalue. 820 if (!E->getBase()->getType()->isVectorType()) 821 return EmitLoadOfLValue(E); 822 823 // Handle the vector case. The base must be a vector, the index must be an 824 // integer value. 825 Value *Base = Visit(E->getBase()); 826 Value *Idx = Visit(E->getIdx()); 827 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerOrEnumerationType(); 828 Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vecidxcast"); 829 return Builder.CreateExtractElement(Base, Idx, "vecext"); 830 } 831 832 static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, 833 unsigned Off, llvm::Type *I32Ty) { 834 int MV = SVI->getMaskValue(Idx); 835 if (MV == -1) 836 return llvm::UndefValue::get(I32Ty); 837 return llvm::ConstantInt::get(I32Ty, Off+MV); 838 } 839 840 Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) { 841 bool Ignore = TestAndClearIgnoreResultAssign(); 842 (void)Ignore; 843 assert (Ignore == false && "init list ignored"); 844 unsigned NumInitElements = E->getNumInits(); 845 846 if (E->hadArrayRangeDesignator()) 847 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 848 849 llvm::VectorType *VType = 850 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 851 852 if (!VType) { 853 if (NumInitElements == 0) { 854 // C++11 value-initialization for the scalar. 855 return EmitNullValue(E->getType()); 856 } 857 // We have a scalar in braces. Just use the first element. 858 return Visit(E->getInit(0)); 859 } 860 861 unsigned ResElts = VType->getNumElements(); 862 863 // Loop over initializers collecting the Value for each, and remembering 864 // whether the source was swizzle (ExtVectorElementExpr). This will allow 865 // us to fold the shuffle for the swizzle into the shuffle for the vector 866 // initializer, since LLVM optimizers generally do not want to touch 867 // shuffles. 868 unsigned CurIdx = 0; 869 bool VIsUndefShuffle = false; 870 llvm::Value *V = llvm::UndefValue::get(VType); 871 for (unsigned i = 0; i != NumInitElements; ++i) { 872 Expr *IE = E->getInit(i); 873 Value *Init = Visit(IE); 874 SmallVector<llvm::Constant*, 16> Args; 875 876 llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType()); 877 878 // Handle scalar elements. If the scalar initializer is actually one 879 // element of a different vector of the same width, use shuffle instead of 880 // extract+insert. 881 if (!VVT) { 882 if (isa<ExtVectorElementExpr>(IE)) { 883 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init); 884 885 if (EI->getVectorOperandType()->getNumElements() == ResElts) { 886 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand()); 887 Value *LHS = 0, *RHS = 0; 888 if (CurIdx == 0) { 889 // insert into undef -> shuffle (src, undef) 890 Args.push_back(C); 891 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 892 893 LHS = EI->getVectorOperand(); 894 RHS = V; 895 VIsUndefShuffle = true; 896 } else if (VIsUndefShuffle) { 897 // insert into undefshuffle && size match -> shuffle (v, src) 898 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V); 899 for (unsigned j = 0; j != CurIdx; ++j) 900 Args.push_back(getMaskElt(SVV, j, 0, CGF.Int32Ty)); 901 Args.push_back(Builder.getInt32(ResElts + C->getZExtValue())); 902 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 903 904 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 905 RHS = EI->getVectorOperand(); 906 VIsUndefShuffle = false; 907 } 908 if (!Args.empty()) { 909 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 910 V = Builder.CreateShuffleVector(LHS, RHS, Mask); 911 ++CurIdx; 912 continue; 913 } 914 } 915 } 916 V = Builder.CreateInsertElement(V, Init, Builder.getInt32(CurIdx), 917 "vecinit"); 918 VIsUndefShuffle = false; 919 ++CurIdx; 920 continue; 921 } 922 923 unsigned InitElts = VVT->getNumElements(); 924 925 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's 926 // input is the same width as the vector being constructed, generate an 927 // optimized shuffle of the swizzle input into the result. 928 unsigned Offset = (CurIdx == 0) ? 0 : ResElts; 929 if (isa<ExtVectorElementExpr>(IE)) { 930 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init); 931 Value *SVOp = SVI->getOperand(0); 932 llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType()); 933 934 if (OpTy->getNumElements() == ResElts) { 935 for (unsigned j = 0; j != CurIdx; ++j) { 936 // If the current vector initializer is a shuffle with undef, merge 937 // this shuffle directly into it. 938 if (VIsUndefShuffle) { 939 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0, 940 CGF.Int32Ty)); 941 } else { 942 Args.push_back(Builder.getInt32(j)); 943 } 944 } 945 for (unsigned j = 0, je = InitElts; j != je; ++j) 946 Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty)); 947 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 948 949 if (VIsUndefShuffle) 950 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 951 952 Init = SVOp; 953 } 954 } 955 956 // Extend init to result vector length, and then shuffle its contribution 957 // to the vector initializer into V. 958 if (Args.empty()) { 959 for (unsigned j = 0; j != InitElts; ++j) 960 Args.push_back(Builder.getInt32(j)); 961 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 962 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 963 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), 964 Mask, "vext"); 965 966 Args.clear(); 967 for (unsigned j = 0; j != CurIdx; ++j) 968 Args.push_back(Builder.getInt32(j)); 969 for (unsigned j = 0; j != InitElts; ++j) 970 Args.push_back(Builder.getInt32(j+Offset)); 971 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 972 } 973 974 // If V is undef, make sure it ends up on the RHS of the shuffle to aid 975 // merging subsequent shuffles into this one. 976 if (CurIdx == 0) 977 std::swap(V, Init); 978 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 979 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); 980 VIsUndefShuffle = isa<llvm::UndefValue>(Init); 981 CurIdx += InitElts; 982 } 983 984 // FIXME: evaluate codegen vs. shuffling against constant null vector. 985 // Emit remaining default initializers. 986 llvm::Type *EltTy = VType->getElementType(); 987 988 // Emit remaining default initializers 989 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { 990 Value *Idx = Builder.getInt32(CurIdx); 991 llvm::Value *Init = llvm::Constant::getNullValue(EltTy); 992 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 993 } 994 return V; 995 } 996 997 static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { 998 const Expr *E = CE->getSubExpr(); 999 1000 if (CE->getCastKind() == CK_UncheckedDerivedToBase) 1001 return false; 1002 1003 if (isa<CXXThisExpr>(E)) { 1004 // We always assume that 'this' is never null. 1005 return false; 1006 } 1007 1008 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { 1009 // And that glvalue casts are never null. 1010 if (ICE->getValueKind() != VK_RValue) 1011 return false; 1012 } 1013 1014 return true; 1015 } 1016 1017 // VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 1018 // have to handle a more broad range of conversions than explicit casts, as they 1019 // handle things like function to ptr-to-function decay etc. 1020 Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) { 1021 Expr *E = CE->getSubExpr(); 1022 QualType DestTy = CE->getType(); 1023 CastKind Kind = CE->getCastKind(); 1024 1025 if (!DestTy->isVoidType()) 1026 TestAndClearIgnoreResultAssign(); 1027 1028 // Since almost all cast kinds apply to scalars, this switch doesn't have 1029 // a default case, so the compiler will warn on a missing case. The cases 1030 // are in the same order as in the CastKind enum. 1031 switch (Kind) { 1032 case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!"); 1033 case CK_BuiltinFnToFnPtr: 1034 llvm_unreachable("builtin functions are handled elsewhere"); 1035 1036 case CK_LValueBitCast: 1037 case CK_ObjCObjectLValueCast: { 1038 Value *V = EmitLValue(E).getAddress(); 1039 V = Builder.CreateBitCast(V, 1040 ConvertType(CGF.getContext().getPointerType(DestTy))); 1041 return EmitLoadOfLValue(CGF.MakeNaturalAlignAddrLValue(V, DestTy)); 1042 } 1043 1044 case CK_CPointerToObjCPointerCast: 1045 case CK_BlockPointerToObjCPointerCast: 1046 case CK_AnyPointerToBlockPointerCast: 1047 case CK_BitCast: { 1048 Value *Src = Visit(const_cast<Expr*>(E)); 1049 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 1050 } 1051 case CK_AtomicToNonAtomic: 1052 case CK_NonAtomicToAtomic: 1053 case CK_NoOp: 1054 case CK_UserDefinedConversion: 1055 return Visit(const_cast<Expr*>(E)); 1056 1057 case CK_BaseToDerived: { 1058 const CXXRecordDecl *DerivedClassDecl = 1059 DestTy->getCXXRecordDeclForPointerType(); 1060 1061 return CGF.GetAddressOfDerivedClass(Visit(E), DerivedClassDecl, 1062 CE->path_begin(), CE->path_end(), 1063 ShouldNullCheckClassCastValue(CE)); 1064 } 1065 case CK_UncheckedDerivedToBase: 1066 case CK_DerivedToBase: { 1067 const RecordType *DerivedClassTy = 1068 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 1069 CXXRecordDecl *DerivedClassDecl = 1070 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 1071 1072 return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl, 1073 CE->path_begin(), CE->path_end(), 1074 ShouldNullCheckClassCastValue(CE)); 1075 } 1076 case CK_Dynamic: { 1077 Value *V = Visit(const_cast<Expr*>(E)); 1078 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 1079 return CGF.EmitDynamicCast(V, DCE); 1080 } 1081 1082 case CK_ArrayToPointerDecay: { 1083 assert(E->getType()->isArrayType() && 1084 "Array to pointer decay must have array source type!"); 1085 1086 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 1087 1088 // Note that VLA pointers are always decayed, so we don't need to do 1089 // anything here. 1090 if (!E->getType()->isVariableArrayType()) { 1091 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 1092 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 1093 ->getElementType()) && 1094 "Expected pointer to array"); 1095 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 1096 } 1097 1098 // Make sure the array decay ends up being the right type. This matters if 1099 // the array type was of an incomplete type. 1100 return CGF.Builder.CreateBitCast(V, ConvertType(CE->getType())); 1101 } 1102 case CK_FunctionToPointerDecay: 1103 return EmitLValue(E).getAddress(); 1104 1105 case CK_NullToPointer: 1106 if (MustVisitNullValue(E)) 1107 (void) Visit(E); 1108 1109 return llvm::ConstantPointerNull::get( 1110 cast<llvm::PointerType>(ConvertType(DestTy))); 1111 1112 case CK_NullToMemberPointer: { 1113 if (MustVisitNullValue(E)) 1114 (void) Visit(E); 1115 1116 const MemberPointerType *MPT = CE->getType()->getAs<MemberPointerType>(); 1117 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 1118 } 1119 1120 case CK_ReinterpretMemberPointer: 1121 case CK_BaseToDerivedMemberPointer: 1122 case CK_DerivedToBaseMemberPointer: { 1123 Value *Src = Visit(E); 1124 1125 // Note that the AST doesn't distinguish between checked and 1126 // unchecked member pointer conversions, so we always have to 1127 // implement checked conversions here. This is inefficient when 1128 // actual control flow may be required in order to perform the 1129 // check, which it is for data member pointers (but not member 1130 // function pointers on Itanium and ARM). 1131 return CGF.CGM.getCXXABI().EmitMemberPointerConversion(CGF, CE, Src); 1132 } 1133 1134 case CK_ARCProduceObject: 1135 return CGF.EmitARCRetainScalarExpr(E); 1136 case CK_ARCConsumeObject: 1137 return CGF.EmitObjCConsumeObject(E->getType(), Visit(E)); 1138 case CK_ARCReclaimReturnedObject: { 1139 llvm::Value *value = Visit(E); 1140 value = CGF.EmitARCRetainAutoreleasedReturnValue(value); 1141 return CGF.EmitObjCConsumeObject(E->getType(), value); 1142 } 1143 case CK_ARCExtendBlockObject: 1144 return CGF.EmitARCExtendBlockObject(E); 1145 1146 case CK_CopyAndAutoreleaseBlockObject: 1147 return CGF.EmitBlockCopyAndAutorelease(Visit(E), E->getType()); 1148 1149 case CK_FloatingRealToComplex: 1150 case CK_FloatingComplexCast: 1151 case CK_IntegralRealToComplex: 1152 case CK_IntegralComplexCast: 1153 case CK_IntegralComplexToFloatingComplex: 1154 case CK_FloatingComplexToIntegralComplex: 1155 case CK_ConstructorConversion: 1156 case CK_ToUnion: 1157 llvm_unreachable("scalar cast to non-scalar value"); 1158 1159 case CK_LValueToRValue: 1160 assert(CGF.getContext().hasSameUnqualifiedType(E->getType(), DestTy)); 1161 assert(E->isGLValue() && "lvalue-to-rvalue applied to r-value!"); 1162 return Visit(const_cast<Expr*>(E)); 1163 1164 case CK_IntegralToPointer: { 1165 Value *Src = Visit(const_cast<Expr*>(E)); 1166 1167 // First, convert to the correct width so that we control the kind of 1168 // extension. 1169 llvm::Type *MiddleTy = CGF.IntPtrTy; 1170 bool InputSigned = E->getType()->isSignedIntegerOrEnumerationType(); 1171 llvm::Value* IntResult = 1172 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 1173 1174 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 1175 } 1176 case CK_PointerToIntegral: 1177 assert(!DestTy->isBooleanType() && "bool should use PointerToBool"); 1178 return Builder.CreatePtrToInt(Visit(E), ConvertType(DestTy)); 1179 1180 case CK_ToVoid: { 1181 CGF.EmitIgnoredExpr(E); 1182 return 0; 1183 } 1184 case CK_VectorSplat: { 1185 llvm::Type *DstTy = ConvertType(DestTy); 1186 Value *Elt = Visit(const_cast<Expr*>(E)); 1187 Elt = EmitScalarConversion(Elt, E->getType(), 1188 DestTy->getAs<VectorType>()->getElementType()); 1189 1190 // Insert the element in element zero of an undef vector 1191 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 1192 llvm::Value *Idx = Builder.getInt32(0); 1193 UnV = Builder.CreateInsertElement(UnV, Elt, Idx); 1194 1195 // Splat the element across to all elements 1196 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 1197 llvm::Constant *Zero = Builder.getInt32(0); 1198 llvm::Constant *Mask = llvm::ConstantVector::getSplat(NumElements, Zero); 1199 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 1200 return Yay; 1201 } 1202 1203 case CK_IntegralCast: 1204 case CK_IntegralToFloating: 1205 case CK_FloatingToIntegral: 1206 case CK_FloatingCast: 1207 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 1208 case CK_IntegralToBoolean: 1209 return EmitIntToBoolConversion(Visit(E)); 1210 case CK_PointerToBoolean: 1211 return EmitPointerToBoolConversion(Visit(E)); 1212 case CK_FloatingToBoolean: 1213 return EmitFloatToBoolConversion(Visit(E)); 1214 case CK_MemberPointerToBoolean: { 1215 llvm::Value *MemPtr = Visit(E); 1216 const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>(); 1217 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT); 1218 } 1219 1220 case CK_FloatingComplexToReal: 1221 case CK_IntegralComplexToReal: 1222 return CGF.EmitComplexExpr(E, false, true).first; 1223 1224 case CK_FloatingComplexToBoolean: 1225 case CK_IntegralComplexToBoolean: { 1226 CodeGenFunction::ComplexPairTy V = CGF.EmitComplexExpr(E); 1227 1228 // TODO: kill this function off, inline appropriate case here 1229 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 1230 } 1231 1232 } 1233 1234 llvm_unreachable("unknown scalar cast"); 1235 } 1236 1237 Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 1238 CodeGenFunction::StmtExprEvaluation eval(CGF); 1239 return CGF.EmitCompoundStmt(*E->getSubStmt(), !E->getType()->isVoidType()) 1240 .getScalarVal(); 1241 } 1242 1243 //===----------------------------------------------------------------------===// 1244 // Unary Operators 1245 //===----------------------------------------------------------------------===// 1246 1247 llvm::Value *ScalarExprEmitter:: 1248 EmitAddConsiderOverflowBehavior(const UnaryOperator *E, 1249 llvm::Value *InVal, 1250 llvm::Value *NextVal, bool IsInc) { 1251 switch (CGF.getContext().getLangOpts().getSignedOverflowBehavior()) { 1252 case LangOptions::SOB_Defined: 1253 return Builder.CreateAdd(InVal, NextVal, IsInc ? "inc" : "dec"); 1254 case LangOptions::SOB_Undefined: 1255 if (!CGF.CatchUndefined) 1256 return Builder.CreateNSWAdd(InVal, NextVal, IsInc ? "inc" : "dec"); 1257 // Fall through. 1258 case LangOptions::SOB_Trapping: 1259 BinOpInfo BinOp; 1260 BinOp.LHS = InVal; 1261 BinOp.RHS = NextVal; 1262 BinOp.Ty = E->getType(); 1263 BinOp.Opcode = BO_Add; 1264 BinOp.E = E; 1265 return EmitOverflowCheckedBinOp(BinOp); 1266 } 1267 llvm_unreachable("Unknown SignedOverflowBehaviorTy"); 1268 } 1269 1270 llvm::Value * 1271 ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 1272 bool isInc, bool isPre) { 1273 1274 QualType type = E->getSubExpr()->getType(); 1275 llvm::Value *value = EmitLoadOfLValue(LV); 1276 llvm::Value *input = value; 1277 llvm::PHINode *atomicPHI = 0; 1278 1279 int amount = (isInc ? 1 : -1); 1280 1281 if (const AtomicType *atomicTy = type->getAs<AtomicType>()) { 1282 llvm::BasicBlock *startBB = Builder.GetInsertBlock(); 1283 llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn); 1284 Builder.CreateBr(opBB); 1285 Builder.SetInsertPoint(opBB); 1286 atomicPHI = Builder.CreatePHI(value->getType(), 2); 1287 atomicPHI->addIncoming(value, startBB); 1288 type = atomicTy->getValueType(); 1289 value = atomicPHI; 1290 } 1291 1292 // Special case of integer increment that we have to check first: bool++. 1293 // Due to promotion rules, we get: 1294 // bool++ -> bool = bool + 1 1295 // -> bool = (int)bool + 1 1296 // -> bool = ((int)bool + 1 != 0) 1297 // An interesting aspect of this is that increment is always true. 1298 // Decrement does not have this property. 1299 if (isInc && type->isBooleanType()) { 1300 value = Builder.getTrue(); 1301 1302 // Most common case by far: integer increment. 1303 } else if (type->isIntegerType()) { 1304 1305 llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount, true); 1306 1307 // Note that signed integer inc/dec with width less than int can't 1308 // overflow because of promotion rules; we're just eliding a few steps here. 1309 if (type->isSignedIntegerOrEnumerationType() && 1310 value->getType()->getPrimitiveSizeInBits() >= 1311 CGF.IntTy->getBitWidth()) 1312 value = EmitAddConsiderOverflowBehavior(E, value, amt, isInc); 1313 else 1314 value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec"); 1315 1316 // Next most common: pointer increment. 1317 } else if (const PointerType *ptr = type->getAs<PointerType>()) { 1318 QualType type = ptr->getPointeeType(); 1319 1320 // VLA types don't have constant size. 1321 if (const VariableArrayType *vla 1322 = CGF.getContext().getAsVariableArrayType(type)) { 1323 llvm::Value *numElts = CGF.getVLASize(vla).first; 1324 if (!isInc) numElts = Builder.CreateNSWNeg(numElts, "vla.negsize"); 1325 if (CGF.getContext().getLangOpts().isSignedOverflowDefined()) 1326 value = Builder.CreateGEP(value, numElts, "vla.inc"); 1327 else 1328 value = Builder.CreateInBoundsGEP(value, numElts, "vla.inc"); 1329 1330 // Arithmetic on function pointers (!) is just +-1. 1331 } else if (type->isFunctionType()) { 1332 llvm::Value *amt = Builder.getInt32(amount); 1333 1334 value = CGF.EmitCastToVoidPtr(value); 1335 if (CGF.getContext().getLangOpts().isSignedOverflowDefined()) 1336 value = Builder.CreateGEP(value, amt, "incdec.funcptr"); 1337 else 1338 value = Builder.CreateInBoundsGEP(value, amt, "incdec.funcptr"); 1339 value = Builder.CreateBitCast(value, input->getType()); 1340 1341 // For everything else, we can just do a simple increment. 1342 } else { 1343 llvm::Value *amt = Builder.getInt32(amount); 1344 if (CGF.getContext().getLangOpts().isSignedOverflowDefined()) 1345 value = Builder.CreateGEP(value, amt, "incdec.ptr"); 1346 else 1347 value = Builder.CreateInBoundsGEP(value, amt, "incdec.ptr"); 1348 } 1349 1350 // Vector increment/decrement. 1351 } else if (type->isVectorType()) { 1352 if (type->hasIntegerRepresentation()) { 1353 llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount); 1354 1355 value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec"); 1356 } else { 1357 value = Builder.CreateFAdd( 1358 value, 1359 llvm::ConstantFP::get(value->getType(), amount), 1360 isInc ? "inc" : "dec"); 1361 } 1362 1363 // Floating point. 1364 } else if (type->isRealFloatingType()) { 1365 // Add the inc/dec to the real part. 1366 llvm::Value *amt; 1367 1368 if (type->isHalfType()) { 1369 // Another special case: half FP increment should be done via float 1370 value = 1371 Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16), 1372 input); 1373 } 1374 1375 if (value->getType()->isFloatTy()) 1376 amt = llvm::ConstantFP::get(VMContext, 1377 llvm::APFloat(static_cast<float>(amount))); 1378 else if (value->getType()->isDoubleTy()) 1379 amt = llvm::ConstantFP::get(VMContext, 1380 llvm::APFloat(static_cast<double>(amount))); 1381 else { 1382 llvm::APFloat F(static_cast<float>(amount)); 1383 bool ignored; 1384 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, 1385 &ignored); 1386 amt = llvm::ConstantFP::get(VMContext, F); 1387 } 1388 value = Builder.CreateFAdd(value, amt, isInc ? "inc" : "dec"); 1389 1390 if (type->isHalfType()) 1391 value = 1392 Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16), 1393 value); 1394 1395 // Objective-C pointer types. 1396 } else { 1397 const ObjCObjectPointerType *OPT = type->castAs<ObjCObjectPointerType>(); 1398 value = CGF.EmitCastToVoidPtr(value); 1399 1400 CharUnits size = CGF.getContext().getTypeSizeInChars(OPT->getObjectType()); 1401 if (!isInc) size = -size; 1402 llvm::Value *sizeValue = 1403 llvm::ConstantInt::get(CGF.SizeTy, size.getQuantity()); 1404 1405 if (CGF.getContext().getLangOpts().isSignedOverflowDefined()) 1406 value = Builder.CreateGEP(value, sizeValue, "incdec.objptr"); 1407 else 1408 value = Builder.CreateInBoundsGEP(value, sizeValue, "incdec.objptr"); 1409 value = Builder.CreateBitCast(value, input->getType()); 1410 } 1411 1412 if (atomicPHI) { 1413 llvm::BasicBlock *opBB = Builder.GetInsertBlock(); 1414 llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn); 1415 llvm::Value *old = Builder.CreateAtomicCmpXchg(LV.getAddress(), atomicPHI, 1416 value, llvm::SequentiallyConsistent); 1417 atomicPHI->addIncoming(old, opBB); 1418 llvm::Value *success = Builder.CreateICmpEQ(old, atomicPHI); 1419 Builder.CreateCondBr(success, contBB, opBB); 1420 Builder.SetInsertPoint(contBB); 1421 return isPre ? value : input; 1422 } 1423 1424 // Store the updated result through the lvalue. 1425 if (LV.isBitField()) 1426 CGF.EmitStoreThroughBitfieldLValue(RValue::get(value), LV, &value); 1427 else 1428 CGF.EmitStoreThroughLValue(RValue::get(value), LV); 1429 1430 // If this is a postinc, return the value read from memory, otherwise use the 1431 // updated value. 1432 return isPre ? value : input; 1433 } 1434 1435 1436 1437 Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1438 TestAndClearIgnoreResultAssign(); 1439 // Emit unary minus with EmitSub so we handle overflow cases etc. 1440 BinOpInfo BinOp; 1441 BinOp.RHS = Visit(E->getSubExpr()); 1442 1443 if (BinOp.RHS->getType()->isFPOrFPVectorTy()) 1444 BinOp.LHS = llvm::ConstantFP::getZeroValueForNegation(BinOp.RHS->getType()); 1445 else 1446 BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType()); 1447 BinOp.Ty = E->getType(); 1448 BinOp.Opcode = BO_Sub; 1449 BinOp.E = E; 1450 return EmitSub(BinOp); 1451 } 1452 1453 Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1454 TestAndClearIgnoreResultAssign(); 1455 Value *Op = Visit(E->getSubExpr()); 1456 return Builder.CreateNot(Op, "neg"); 1457 } 1458 1459 Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1460 1461 // Perform vector logical not on comparison with zero vector. 1462 if (E->getType()->isExtVectorType()) { 1463 Value *Oper = Visit(E->getSubExpr()); 1464 Value *Zero = llvm::Constant::getNullValue(Oper->getType()); 1465 Value *Result = Builder.CreateICmp(llvm::CmpInst::ICMP_EQ, Oper, Zero, "cmp"); 1466 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 1467 } 1468 1469 // Compare operand to zero. 1470 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1471 1472 // Invert value. 1473 // TODO: Could dynamically modify easy computations here. For example, if 1474 // the operand is an icmp ne, turn into icmp eq. 1475 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1476 1477 // ZExt result to the expr type. 1478 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1479 } 1480 1481 Value *ScalarExprEmitter::VisitOffsetOfExpr(OffsetOfExpr *E) { 1482 // Try folding the offsetof to a constant. 1483 llvm::APSInt Value; 1484 if (E->EvaluateAsInt(Value, CGF.getContext())) 1485 return Builder.getInt(Value); 1486 1487 // Loop over the components of the offsetof to compute the value. 1488 unsigned n = E->getNumComponents(); 1489 llvm::Type* ResultType = ConvertType(E->getType()); 1490 llvm::Value* Result = llvm::Constant::getNullValue(ResultType); 1491 QualType CurrentType = E->getTypeSourceInfo()->getType(); 1492 for (unsigned i = 0; i != n; ++i) { 1493 OffsetOfExpr::OffsetOfNode ON = E->getComponent(i); 1494 llvm::Value *Offset = 0; 1495 switch (ON.getKind()) { 1496 case OffsetOfExpr::OffsetOfNode::Array: { 1497 // Compute the index 1498 Expr *IdxExpr = E->getIndexExpr(ON.getArrayExprIndex()); 1499 llvm::Value* Idx = CGF.EmitScalarExpr(IdxExpr); 1500 bool IdxSigned = IdxExpr->getType()->isSignedIntegerOrEnumerationType(); 1501 Idx = Builder.CreateIntCast(Idx, ResultType, IdxSigned, "conv"); 1502 1503 // Save the element type 1504 CurrentType = 1505 CGF.getContext().getAsArrayType(CurrentType)->getElementType(); 1506 1507 // Compute the element size 1508 llvm::Value* ElemSize = llvm::ConstantInt::get(ResultType, 1509 CGF.getContext().getTypeSizeInChars(CurrentType).getQuantity()); 1510 1511 // Multiply out to compute the result 1512 Offset = Builder.CreateMul(Idx, ElemSize); 1513 break; 1514 } 1515 1516 case OffsetOfExpr::OffsetOfNode::Field: { 1517 FieldDecl *MemberDecl = ON.getField(); 1518 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1519 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1520 1521 // Compute the index of the field in its parent. 1522 unsigned i = 0; 1523 // FIXME: It would be nice if we didn't have to loop here! 1524 for (RecordDecl::field_iterator Field = RD->field_begin(), 1525 FieldEnd = RD->field_end(); 1526 Field != FieldEnd; ++Field, ++i) { 1527 if (*Field == MemberDecl) 1528 break; 1529 } 1530 assert(i < RL.getFieldCount() && "offsetof field in wrong type"); 1531 1532 // Compute the offset to the field 1533 int64_t OffsetInt = RL.getFieldOffset(i) / 1534 CGF.getContext().getCharWidth(); 1535 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1536 1537 // Save the element type. 1538 CurrentType = MemberDecl->getType(); 1539 break; 1540 } 1541 1542 case OffsetOfExpr::OffsetOfNode::Identifier: 1543 llvm_unreachable("dependent __builtin_offsetof"); 1544 1545 case OffsetOfExpr::OffsetOfNode::Base: { 1546 if (ON.getBase()->isVirtual()) { 1547 CGF.ErrorUnsupported(E, "virtual base in offsetof"); 1548 continue; 1549 } 1550 1551 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1552 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1553 1554 // Save the element type. 1555 CurrentType = ON.getBase()->getType(); 1556 1557 // Compute the offset to the base. 1558 const RecordType *BaseRT = CurrentType->getAs<RecordType>(); 1559 CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl()); 1560 CharUnits OffsetInt = RL.getBaseClassOffset(BaseRD); 1561 Offset = llvm::ConstantInt::get(ResultType, OffsetInt.getQuantity()); 1562 break; 1563 } 1564 } 1565 Result = Builder.CreateAdd(Result, Offset); 1566 } 1567 return Result; 1568 } 1569 1570 /// VisitUnaryExprOrTypeTraitExpr - Return the size or alignment of the type of 1571 /// argument of the sizeof expression as an integer. 1572 Value * 1573 ScalarExprEmitter::VisitUnaryExprOrTypeTraitExpr( 1574 const UnaryExprOrTypeTraitExpr *E) { 1575 QualType TypeToSize = E->getTypeOfArgument(); 1576 if (E->getKind() == UETT_SizeOf) { 1577 if (const VariableArrayType *VAT = 1578 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1579 if (E->isArgumentType()) { 1580 // sizeof(type) - make sure to emit the VLA size. 1581 CGF.EmitVariablyModifiedType(TypeToSize); 1582 } else { 1583 // C99 6.5.3.4p2: If the argument is an expression of type 1584 // VLA, it is evaluated. 1585 CGF.EmitIgnoredExpr(E->getArgumentExpr()); 1586 } 1587 1588 QualType eltType; 1589 llvm::Value *numElts; 1590 llvm::tie(numElts, eltType) = CGF.getVLASize(VAT); 1591 1592 llvm::Value *size = numElts; 1593 1594 // Scale the number of non-VLA elements by the non-VLA element size. 1595 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType); 1596 if (!eltSize.isOne()) 1597 size = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), numElts); 1598 1599 return size; 1600 } 1601 } 1602 1603 // If this isn't sizeof(vla), the result must be constant; use the constant 1604 // folding logic so we don't have to duplicate it here. 1605 return Builder.getInt(E->EvaluateKnownConstInt(CGF.getContext())); 1606 } 1607 1608 Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1609 Expr *Op = E->getSubExpr(); 1610 if (Op->getType()->isAnyComplexType()) { 1611 // If it's an l-value, load through the appropriate subobject l-value. 1612 // Note that we have to ask E because Op might be an l-value that 1613 // this won't work for, e.g. an Obj-C property. 1614 if (E->isGLValue()) 1615 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E)).getScalarVal(); 1616 1617 // Otherwise, calculate and project. 1618 return CGF.EmitComplexExpr(Op, false, true).first; 1619 } 1620 1621 return Visit(Op); 1622 } 1623 1624 Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1625 Expr *Op = E->getSubExpr(); 1626 if (Op->getType()->isAnyComplexType()) { 1627 // If it's an l-value, load through the appropriate subobject l-value. 1628 // Note that we have to ask E because Op might be an l-value that 1629 // this won't work for, e.g. an Obj-C property. 1630 if (Op->isGLValue()) 1631 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E)).getScalarVal(); 1632 1633 // Otherwise, calculate and project. 1634 return CGF.EmitComplexExpr(Op, true, false).second; 1635 } 1636 1637 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1638 // effects are evaluated, but not the actual value. 1639 if (Op->isGLValue()) 1640 CGF.EmitLValue(Op); 1641 else 1642 CGF.EmitScalarExpr(Op, true); 1643 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1644 } 1645 1646 //===----------------------------------------------------------------------===// 1647 // Binary Operators 1648 //===----------------------------------------------------------------------===// 1649 1650 BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1651 TestAndClearIgnoreResultAssign(); 1652 BinOpInfo Result; 1653 Result.LHS = Visit(E->getLHS()); 1654 Result.RHS = Visit(E->getRHS()); 1655 Result.Ty = E->getType(); 1656 Result.Opcode = E->getOpcode(); 1657 Result.E = E; 1658 return Result; 1659 } 1660 1661 LValue ScalarExprEmitter::EmitCompoundAssignLValue( 1662 const CompoundAssignOperator *E, 1663 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &), 1664 Value *&Result) { 1665 QualType LHSTy = E->getLHS()->getType(); 1666 BinOpInfo OpInfo; 1667 1668 if (E->getComputationResultType()->isAnyComplexType()) { 1669 // This needs to go through the complex expression emitter, but it's a tad 1670 // complicated to do that... I'm leaving it out for now. (Note that we do 1671 // actually need the imaginary part of the RHS for multiplication and 1672 // division.) 1673 CGF.ErrorUnsupported(E, "complex compound assignment"); 1674 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType())); 1675 return LValue(); 1676 } 1677 1678 // Emit the RHS first. __block variables need to have the rhs evaluated 1679 // first, plus this should improve codegen a little. 1680 OpInfo.RHS = Visit(E->getRHS()); 1681 OpInfo.Ty = E->getComputationResultType(); 1682 OpInfo.Opcode = E->getOpcode(); 1683 OpInfo.E = E; 1684 // Load/convert the LHS. 1685 LValue LHSLV = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store); 1686 OpInfo.LHS = EmitLoadOfLValue(LHSLV); 1687 1688 llvm::PHINode *atomicPHI = 0; 1689 if (LHSTy->isAtomicType()) { 1690 // FIXME: For floating point types, we should be saving and restoring the 1691 // floating point environment in the loop. 1692 llvm::BasicBlock *startBB = Builder.GetInsertBlock(); 1693 llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn); 1694 Builder.CreateBr(opBB); 1695 Builder.SetInsertPoint(opBB); 1696 atomicPHI = Builder.CreatePHI(OpInfo.LHS->getType(), 2); 1697 atomicPHI->addIncoming(OpInfo.LHS, startBB); 1698 OpInfo.LHS = atomicPHI; 1699 } 1700 1701 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 1702 E->getComputationLHSType()); 1703 1704 // Expand the binary operator. 1705 Result = (this->*Func)(OpInfo); 1706 1707 // Convert the result back to the LHS type. 1708 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 1709 1710 if (atomicPHI) { 1711 llvm::BasicBlock *opBB = Builder.GetInsertBlock(); 1712 llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn); 1713 llvm::Value *old = Builder.CreateAtomicCmpXchg(LHSLV.getAddress(), atomicPHI, 1714 Result, llvm::SequentiallyConsistent); 1715 atomicPHI->addIncoming(old, opBB); 1716 llvm::Value *success = Builder.CreateICmpEQ(old, atomicPHI); 1717 Builder.CreateCondBr(success, contBB, opBB); 1718 Builder.SetInsertPoint(contBB); 1719 return LHSLV; 1720 } 1721 1722 // Store the result value into the LHS lvalue. Bit-fields are handled 1723 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 1724 // 'An assignment expression has the value of the left operand after the 1725 // assignment...'. 1726 if (LHSLV.isBitField()) 1727 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, &Result); 1728 else 1729 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV); 1730 1731 return LHSLV; 1732 } 1733 1734 Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 1735 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 1736 bool Ignore = TestAndClearIgnoreResultAssign(); 1737 Value *RHS; 1738 LValue LHS = EmitCompoundAssignLValue(E, Func, RHS); 1739 1740 // If the result is clearly ignored, return now. 1741 if (Ignore) 1742 return 0; 1743 1744 // The result of an assignment in C is the assigned r-value. 1745 if (!CGF.getContext().getLangOpts().CPlusPlus) 1746 return RHS; 1747 1748 // If the lvalue is non-volatile, return the computed value of the assignment. 1749 if (!LHS.isVolatileQualified()) 1750 return RHS; 1751 1752 // Otherwise, reload the value. 1753 return EmitLoadOfLValue(LHS); 1754 } 1755 1756 void ScalarExprEmitter::EmitUndefinedBehaviorIntegerDivAndRemCheck( 1757 const BinOpInfo &Ops, llvm::Value *Zero, bool isDiv) { 1758 llvm::IntegerType *Ty = cast<llvm::IntegerType>(Zero->getType()); 1759 1760 if (Ops.Ty->hasSignedIntegerRepresentation()) { 1761 llvm::Value *IntMin = 1762 Builder.getInt(llvm::APInt::getSignedMinValue(Ty->getBitWidth())); 1763 llvm::Value *NegOne = llvm::ConstantInt::get(Ty, -1ULL); 1764 1765 llvm::Value *Cond1 = Builder.CreateICmpNE(Ops.RHS, Zero); 1766 llvm::Value *LHSCmp = Builder.CreateICmpNE(Ops.LHS, IntMin); 1767 llvm::Value *RHSCmp = Builder.CreateICmpNE(Ops.RHS, NegOne); 1768 llvm::Value *Cond2 = Builder.CreateOr(LHSCmp, RHSCmp, "or"); 1769 CGF.EmitCheck(Builder.CreateAnd(Cond1, Cond2, "and")); 1770 } else { 1771 CGF.EmitCheck(Builder.CreateICmpNE(Ops.RHS, Zero)); 1772 } 1773 } 1774 1775 Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 1776 if (isTrapvOverflowBehavior()) { 1777 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 1778 1779 if (Ops.Ty->isIntegerType()) 1780 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, true); 1781 else if (Ops.Ty->isRealFloatingType()) 1782 CGF.EmitCheck(Builder.CreateFCmpUNE(Ops.RHS, Zero)); 1783 } 1784 if (Ops.LHS->getType()->isFPOrFPVectorTy()) { 1785 llvm::Value *Val = Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 1786 if (CGF.getContext().getLangOpts().OpenCL) { 1787 // OpenCL 1.1 7.4: minimum accuracy of single precision / is 2.5ulp 1788 llvm::Type *ValTy = Val->getType(); 1789 if (ValTy->isFloatTy() || 1790 (isa<llvm::VectorType>(ValTy) && 1791 cast<llvm::VectorType>(ValTy)->getElementType()->isFloatTy())) 1792 CGF.SetFPAccuracy(Val, 2.5); 1793 } 1794 return Val; 1795 } 1796 else if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1797 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 1798 else 1799 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 1800 } 1801 1802 Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 1803 // Rem in C can't be a floating point type: C99 6.5.5p2. 1804 if (isTrapvOverflowBehavior()) { 1805 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 1806 1807 if (Ops.Ty->isIntegerType()) 1808 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, false); 1809 } 1810 1811 if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1812 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 1813 else 1814 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 1815 } 1816 1817 Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 1818 unsigned IID; 1819 unsigned OpID = 0; 1820 1821 switch (Ops.Opcode) { 1822 case BO_Add: 1823 case BO_AddAssign: 1824 OpID = 1; 1825 IID = llvm::Intrinsic::sadd_with_overflow; 1826 break; 1827 case BO_Sub: 1828 case BO_SubAssign: 1829 OpID = 2; 1830 IID = llvm::Intrinsic::ssub_with_overflow; 1831 break; 1832 case BO_Mul: 1833 case BO_MulAssign: 1834 OpID = 3; 1835 IID = llvm::Intrinsic::smul_with_overflow; 1836 break; 1837 default: 1838 llvm_unreachable("Unsupported operation for overflow detection"); 1839 } 1840 OpID <<= 1; 1841 OpID |= 1; 1842 1843 llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1844 1845 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, opTy); 1846 1847 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1848 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1849 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1850 1851 // Handle overflow with llvm.trap if no custom handler has been specified. 1852 const std::string *handlerName = 1853 &CGF.getContext().getLangOpts().OverflowHandler; 1854 if (handlerName->empty()) { 1855 CGF.EmitCheck(Builder.CreateNot(overflow)); 1856 return result; 1857 } 1858 1859 // Branch in case of overflow. 1860 llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); 1861 llvm::Function::iterator insertPt = initialBB; 1862 llvm::BasicBlock *continueBB = CGF.createBasicBlock("nooverflow", CGF.CurFn, 1863 llvm::next(insertPt)); 1864 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); 1865 1866 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1867 1868 // If an overflow handler is set, then we want to call it and then use its 1869 // result, if it returns. 1870 Builder.SetInsertPoint(overflowBB); 1871 1872 // Get the overflow handler. 1873 llvm::Type *Int8Ty = CGF.Int8Ty; 1874 llvm::Type *argTypes[] = { CGF.Int64Ty, CGF.Int64Ty, Int8Ty, Int8Ty }; 1875 llvm::FunctionType *handlerTy = 1876 llvm::FunctionType::get(CGF.Int64Ty, argTypes, true); 1877 llvm::Value *handler = CGF.CGM.CreateRuntimeFunction(handlerTy, *handlerName); 1878 1879 // Sign extend the args to 64-bit, so that we can use the same handler for 1880 // all types of overflow. 1881 llvm::Value *lhs = Builder.CreateSExt(Ops.LHS, CGF.Int64Ty); 1882 llvm::Value *rhs = Builder.CreateSExt(Ops.RHS, CGF.Int64Ty); 1883 1884 // Call the handler with the two arguments, the operation, and the size of 1885 // the result. 1886 llvm::Value *handlerResult = Builder.CreateCall4(handler, lhs, rhs, 1887 Builder.getInt8(OpID), 1888 Builder.getInt8(cast<llvm::IntegerType>(opTy)->getBitWidth())); 1889 1890 // Truncate the result back to the desired size. 1891 handlerResult = Builder.CreateTrunc(handlerResult, opTy); 1892 Builder.CreateBr(continueBB); 1893 1894 Builder.SetInsertPoint(continueBB); 1895 llvm::PHINode *phi = Builder.CreatePHI(opTy, 2); 1896 phi->addIncoming(result, initialBB); 1897 phi->addIncoming(handlerResult, overflowBB); 1898 1899 return phi; 1900 } 1901 1902 /// Emit pointer + index arithmetic. 1903 static Value *emitPointerArithmetic(CodeGenFunction &CGF, 1904 const BinOpInfo &op, 1905 bool isSubtraction) { 1906 // Must have binary (not unary) expr here. Unary pointer 1907 // increment/decrement doesn't use this path. 1908 const BinaryOperator *expr = cast<BinaryOperator>(op.E); 1909 1910 Value *pointer = op.LHS; 1911 Expr *pointerOperand = expr->getLHS(); 1912 Value *index = op.RHS; 1913 Expr *indexOperand = expr->getRHS(); 1914 1915 // In a subtraction, the LHS is always the pointer. 1916 if (!isSubtraction && !pointer->getType()->isPointerTy()) { 1917 std::swap(pointer, index); 1918 std::swap(pointerOperand, indexOperand); 1919 } 1920 1921 unsigned width = cast<llvm::IntegerType>(index->getType())->getBitWidth(); 1922 if (width != CGF.PointerWidthInBits) { 1923 // Zero-extend or sign-extend the pointer value according to 1924 // whether the index is signed or not. 1925 bool isSigned = indexOperand->getType()->isSignedIntegerOrEnumerationType(); 1926 index = CGF.Builder.CreateIntCast(index, CGF.PtrDiffTy, isSigned, 1927 "idx.ext"); 1928 } 1929 1930 // If this is subtraction, negate the index. 1931 if (isSubtraction) 1932 index = CGF.Builder.CreateNeg(index, "idx.neg"); 1933 1934 const PointerType *pointerType 1935 = pointerOperand->getType()->getAs<PointerType>(); 1936 if (!pointerType) { 1937 QualType objectType = pointerOperand->getType() 1938 ->castAs<ObjCObjectPointerType>() 1939 ->getPointeeType(); 1940 llvm::Value *objectSize 1941 = CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(objectType)); 1942 1943 index = CGF.Builder.CreateMul(index, objectSize); 1944 1945 Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy); 1946 result = CGF.Builder.CreateGEP(result, index, "add.ptr"); 1947 return CGF.Builder.CreateBitCast(result, pointer->getType()); 1948 } 1949 1950 QualType elementType = pointerType->getPointeeType(); 1951 if (const VariableArrayType *vla 1952 = CGF.getContext().getAsVariableArrayType(elementType)) { 1953 // The element count here is the total number of non-VLA elements. 1954 llvm::Value *numElements = CGF.getVLASize(vla).first; 1955 1956 // Effectively, the multiply by the VLA size is part of the GEP. 1957 // GEP indexes are signed, and scaling an index isn't permitted to 1958 // signed-overflow, so we use the same semantics for our explicit 1959 // multiply. We suppress this if overflow is not undefined behavior. 1960 if (CGF.getLangOpts().isSignedOverflowDefined()) { 1961 index = CGF.Builder.CreateMul(index, numElements, "vla.index"); 1962 pointer = CGF.Builder.CreateGEP(pointer, index, "add.ptr"); 1963 } else { 1964 index = CGF.Builder.CreateNSWMul(index, numElements, "vla.index"); 1965 pointer = CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr"); 1966 } 1967 return pointer; 1968 } 1969 1970 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 1971 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 1972 // future proof. 1973 if (elementType->isVoidType() || elementType->isFunctionType()) { 1974 Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy); 1975 result = CGF.Builder.CreateGEP(result, index, "add.ptr"); 1976 return CGF.Builder.CreateBitCast(result, pointer->getType()); 1977 } 1978 1979 if (CGF.getLangOpts().isSignedOverflowDefined()) 1980 return CGF.Builder.CreateGEP(pointer, index, "add.ptr"); 1981 1982 return CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr"); 1983 } 1984 1985 Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &op) { 1986 if (op.LHS->getType()->isPointerTy() || 1987 op.RHS->getType()->isPointerTy()) 1988 return emitPointerArithmetic(CGF, op, /*subtraction*/ false); 1989 1990 if (op.Ty->isSignedIntegerOrEnumerationType()) { 1991 switch (CGF.getContext().getLangOpts().getSignedOverflowBehavior()) { 1992 case LangOptions::SOB_Defined: 1993 return Builder.CreateAdd(op.LHS, op.RHS, "add"); 1994 case LangOptions::SOB_Undefined: 1995 if (!CGF.CatchUndefined) 1996 return Builder.CreateNSWAdd(op.LHS, op.RHS, "add"); 1997 // Fall through. 1998 case LangOptions::SOB_Trapping: 1999 return EmitOverflowCheckedBinOp(op); 2000 } 2001 } 2002 2003 if (op.LHS->getType()->isFPOrFPVectorTy()) 2004 return Builder.CreateFAdd(op.LHS, op.RHS, "add"); 2005 2006 return Builder.CreateAdd(op.LHS, op.RHS, "add"); 2007 } 2008 2009 Value *ScalarExprEmitter::EmitSub(const BinOpInfo &op) { 2010 // The LHS is always a pointer if either side is. 2011 if (!op.LHS->getType()->isPointerTy()) { 2012 if (op.Ty->isSignedIntegerOrEnumerationType()) { 2013 switch (CGF.getContext().getLangOpts().getSignedOverflowBehavior()) { 2014 case LangOptions::SOB_Defined: 2015 return Builder.CreateSub(op.LHS, op.RHS, "sub"); 2016 case LangOptions::SOB_Undefined: 2017 if (!CGF.CatchUndefined) 2018 return Builder.CreateNSWSub(op.LHS, op.RHS, "sub"); 2019 // Fall through. 2020 case LangOptions::SOB_Trapping: 2021 return EmitOverflowCheckedBinOp(op); 2022 } 2023 } 2024 2025 if (op.LHS->getType()->isFPOrFPVectorTy()) 2026 return Builder.CreateFSub(op.LHS, op.RHS, "sub"); 2027 2028 return Builder.CreateSub(op.LHS, op.RHS, "sub"); 2029 } 2030 2031 // If the RHS is not a pointer, then we have normal pointer 2032 // arithmetic. 2033 if (!op.RHS->getType()->isPointerTy()) 2034 return emitPointerArithmetic(CGF, op, /*subtraction*/ true); 2035 2036 // Otherwise, this is a pointer subtraction. 2037 2038 // Do the raw subtraction part. 2039 llvm::Value *LHS 2040 = Builder.CreatePtrToInt(op.LHS, CGF.PtrDiffTy, "sub.ptr.lhs.cast"); 2041 llvm::Value *RHS 2042 = Builder.CreatePtrToInt(op.RHS, CGF.PtrDiffTy, "sub.ptr.rhs.cast"); 2043 Value *diffInChars = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 2044 2045 // Okay, figure out the element size. 2046 const BinaryOperator *expr = cast<BinaryOperator>(op.E); 2047 QualType elementType = expr->getLHS()->getType()->getPointeeType(); 2048 2049 llvm::Value *divisor = 0; 2050 2051 // For a variable-length array, this is going to be non-constant. 2052 if (const VariableArrayType *vla 2053 = CGF.getContext().getAsVariableArrayType(elementType)) { 2054 llvm::Value *numElements; 2055 llvm::tie(numElements, elementType) = CGF.getVLASize(vla); 2056 2057 divisor = numElements; 2058 2059 // Scale the number of non-VLA elements by the non-VLA element size. 2060 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(elementType); 2061 if (!eltSize.isOne()) 2062 divisor = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), divisor); 2063 2064 // For everything elese, we can just compute it, safe in the 2065 // assumption that Sema won't let anything through that we can't 2066 // safely compute the size of. 2067 } else { 2068 CharUnits elementSize; 2069 // Handle GCC extension for pointer arithmetic on void* and 2070 // function pointer types. 2071 if (elementType->isVoidType() || elementType->isFunctionType()) 2072 elementSize = CharUnits::One(); 2073 else 2074 elementSize = CGF.getContext().getTypeSizeInChars(elementType); 2075 2076 // Don't even emit the divide for element size of 1. 2077 if (elementSize.isOne()) 2078 return diffInChars; 2079 2080 divisor = CGF.CGM.getSize(elementSize); 2081 } 2082 2083 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 2084 // pointer difference in C is only defined in the case where both operands 2085 // are pointing to elements of an array. 2086 return Builder.CreateExactSDiv(diffInChars, divisor, "sub.ptr.div"); 2087 } 2088 2089 Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 2090 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 2091 // RHS to the same size as the LHS. 2092 Value *RHS = Ops.RHS; 2093 if (Ops.LHS->getType() != RHS->getType()) 2094 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 2095 2096 if (CGF.CatchUndefined && isa<llvm::IntegerType>(Ops.LHS->getType())) { 2097 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 2098 llvm::Value *WidthMinusOne = 2099 llvm::ConstantInt::get(RHS->getType(), Width - 1); 2100 CGF.EmitCheck(Builder.CreateICmpULE(RHS, WidthMinusOne)); 2101 2102 if (Ops.Ty->hasSignedIntegerRepresentation()) { 2103 // Check whether we are shifting any non-zero bits off the top of the 2104 // integer. 2105 llvm::Value *BitsShiftedOff = 2106 Builder.CreateLShr(Ops.LHS, 2107 Builder.CreateSub(WidthMinusOne, RHS, "shl.zeros", 2108 /*NUW*/true, /*NSW*/true), 2109 "shl.check"); 2110 if (CGF.getLangOpts().CPlusPlus) { 2111 // In C99, we are not permitted to shift a 1 bit into the sign bit. 2112 // Under C++11's rules, shifting a 1 bit into the sign bit is 2113 // OK, but shifting a 1 bit out of it is not. (C89 and C++03 don't 2114 // define signed left shifts, so we use the C99 and C++11 rules there). 2115 llvm::Value *One = llvm::ConstantInt::get(BitsShiftedOff->getType(), 1); 2116 BitsShiftedOff = Builder.CreateLShr(BitsShiftedOff, One); 2117 } 2118 llvm::Value *Zero = llvm::ConstantInt::get(BitsShiftedOff->getType(), 0); 2119 CGF.EmitCheck(Builder.CreateICmpEQ(BitsShiftedOff, Zero)); 2120 } 2121 } 2122 2123 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 2124 } 2125 2126 Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 2127 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 2128 // RHS to the same size as the LHS. 2129 Value *RHS = Ops.RHS; 2130 if (Ops.LHS->getType() != RHS->getType()) 2131 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 2132 2133 if (CGF.CatchUndefined && isa<llvm::IntegerType>(Ops.LHS->getType())) { 2134 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 2135 llvm::Value *WidthVal = llvm::ConstantInt::get(RHS->getType(), Width); 2136 CGF.EmitCheck(Builder.CreateICmpULT(RHS, WidthVal)); 2137 } 2138 2139 if (Ops.Ty->hasUnsignedIntegerRepresentation()) 2140 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 2141 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 2142 } 2143 2144 enum IntrinsicType { VCMPEQ, VCMPGT }; 2145 // return corresponding comparison intrinsic for given vector type 2146 static llvm::Intrinsic::ID GetIntrinsic(IntrinsicType IT, 2147 BuiltinType::Kind ElemKind) { 2148 switch (ElemKind) { 2149 default: llvm_unreachable("unexpected element type"); 2150 case BuiltinType::Char_U: 2151 case BuiltinType::UChar: 2152 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p : 2153 llvm::Intrinsic::ppc_altivec_vcmpgtub_p; 2154 case BuiltinType::Char_S: 2155 case BuiltinType::SChar: 2156 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p : 2157 llvm::Intrinsic::ppc_altivec_vcmpgtsb_p; 2158 case BuiltinType::UShort: 2159 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p : 2160 llvm::Intrinsic::ppc_altivec_vcmpgtuh_p; 2161 case BuiltinType::Short: 2162 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p : 2163 llvm::Intrinsic::ppc_altivec_vcmpgtsh_p; 2164 case BuiltinType::UInt: 2165 case BuiltinType::ULong: 2166 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p : 2167 llvm::Intrinsic::ppc_altivec_vcmpgtuw_p; 2168 case BuiltinType::Int: 2169 case BuiltinType::Long: 2170 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p : 2171 llvm::Intrinsic::ppc_altivec_vcmpgtsw_p; 2172 case BuiltinType::Float: 2173 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpeqfp_p : 2174 llvm::Intrinsic::ppc_altivec_vcmpgtfp_p; 2175 } 2176 } 2177 2178 Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 2179 unsigned SICmpOpc, unsigned FCmpOpc) { 2180 TestAndClearIgnoreResultAssign(); 2181 Value *Result; 2182 QualType LHSTy = E->getLHS()->getType(); 2183 if (const MemberPointerType *MPT = LHSTy->getAs<MemberPointerType>()) { 2184 assert(E->getOpcode() == BO_EQ || 2185 E->getOpcode() == BO_NE); 2186 Value *LHS = CGF.EmitScalarExpr(E->getLHS()); 2187 Value *RHS = CGF.EmitScalarExpr(E->getRHS()); 2188 Result = CGF.CGM.getCXXABI().EmitMemberPointerComparison( 2189 CGF, LHS, RHS, MPT, E->getOpcode() == BO_NE); 2190 } else if (!LHSTy->isAnyComplexType()) { 2191 Value *LHS = Visit(E->getLHS()); 2192 Value *RHS = Visit(E->getRHS()); 2193 2194 // If AltiVec, the comparison results in a numeric type, so we use 2195 // intrinsics comparing vectors and giving 0 or 1 as a result 2196 if (LHSTy->isVectorType() && !E->getType()->isVectorType()) { 2197 // constants for mapping CR6 register bits to predicate result 2198 enum { CR6_EQ=0, CR6_EQ_REV, CR6_LT, CR6_LT_REV } CR6; 2199 2200 llvm::Intrinsic::ID ID = llvm::Intrinsic::not_intrinsic; 2201 2202 // in several cases vector arguments order will be reversed 2203 Value *FirstVecArg = LHS, 2204 *SecondVecArg = RHS; 2205 2206 QualType ElTy = LHSTy->getAs<VectorType>()->getElementType(); 2207 const BuiltinType *BTy = ElTy->getAs<BuiltinType>(); 2208 BuiltinType::Kind ElementKind = BTy->getKind(); 2209 2210 switch(E->getOpcode()) { 2211 default: llvm_unreachable("is not a comparison operation"); 2212 case BO_EQ: 2213 CR6 = CR6_LT; 2214 ID = GetIntrinsic(VCMPEQ, ElementKind); 2215 break; 2216 case BO_NE: 2217 CR6 = CR6_EQ; 2218 ID = GetIntrinsic(VCMPEQ, ElementKind); 2219 break; 2220 case BO_LT: 2221 CR6 = CR6_LT; 2222 ID = GetIntrinsic(VCMPGT, ElementKind); 2223 std::swap(FirstVecArg, SecondVecArg); 2224 break; 2225 case BO_GT: 2226 CR6 = CR6_LT; 2227 ID = GetIntrinsic(VCMPGT, ElementKind); 2228 break; 2229 case BO_LE: 2230 if (ElementKind == BuiltinType::Float) { 2231 CR6 = CR6_LT; 2232 ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p; 2233 std::swap(FirstVecArg, SecondVecArg); 2234 } 2235 else { 2236 CR6 = CR6_EQ; 2237 ID = GetIntrinsic(VCMPGT, ElementKind); 2238 } 2239 break; 2240 case BO_GE: 2241 if (ElementKind == BuiltinType::Float) { 2242 CR6 = CR6_LT; 2243 ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p; 2244 } 2245 else { 2246 CR6 = CR6_EQ; 2247 ID = GetIntrinsic(VCMPGT, ElementKind); 2248 std::swap(FirstVecArg, SecondVecArg); 2249 } 2250 break; 2251 } 2252 2253 Value *CR6Param = Builder.getInt32(CR6); 2254 llvm::Function *F = CGF.CGM.getIntrinsic(ID); 2255 Result = Builder.CreateCall3(F, CR6Param, FirstVecArg, SecondVecArg, ""); 2256 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 2257 } 2258 2259 if (LHS->getType()->isFPOrFPVectorTy()) { 2260 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 2261 LHS, RHS, "cmp"); 2262 } else if (LHSTy->hasSignedIntegerRepresentation()) { 2263 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 2264 LHS, RHS, "cmp"); 2265 } else { 2266 // Unsigned integers and pointers. 2267 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2268 LHS, RHS, "cmp"); 2269 } 2270 2271 // If this is a vector comparison, sign extend the result to the appropriate 2272 // vector integer type and return it (don't convert to bool). 2273 if (LHSTy->isVectorType()) 2274 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 2275 2276 } else { 2277 // Complex Comparison: can only be an equality comparison. 2278 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 2279 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 2280 2281 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 2282 2283 Value *ResultR, *ResultI; 2284 if (CETy->isRealFloatingType()) { 2285 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 2286 LHS.first, RHS.first, "cmp.r"); 2287 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 2288 LHS.second, RHS.second, "cmp.i"); 2289 } else { 2290 // Complex comparisons can only be equality comparisons. As such, signed 2291 // and unsigned opcodes are the same. 2292 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2293 LHS.first, RHS.first, "cmp.r"); 2294 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2295 LHS.second, RHS.second, "cmp.i"); 2296 } 2297 2298 if (E->getOpcode() == BO_EQ) { 2299 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 2300 } else { 2301 assert(E->getOpcode() == BO_NE && 2302 "Complex comparison other than == or != ?"); 2303 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 2304 } 2305 } 2306 2307 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 2308 } 2309 2310 Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 2311 bool Ignore = TestAndClearIgnoreResultAssign(); 2312 2313 Value *RHS; 2314 LValue LHS; 2315 2316 switch (E->getLHS()->getType().getObjCLifetime()) { 2317 case Qualifiers::OCL_Strong: 2318 llvm::tie(LHS, RHS) = CGF.EmitARCStoreStrong(E, Ignore); 2319 break; 2320 2321 case Qualifiers::OCL_Autoreleasing: 2322 llvm::tie(LHS,RHS) = CGF.EmitARCStoreAutoreleasing(E); 2323 break; 2324 2325 case Qualifiers::OCL_Weak: 2326 RHS = Visit(E->getRHS()); 2327 LHS = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store); 2328 RHS = CGF.EmitARCStoreWeak(LHS.getAddress(), RHS, Ignore); 2329 break; 2330 2331 // No reason to do any of these differently. 2332 case Qualifiers::OCL_None: 2333 case Qualifiers::OCL_ExplicitNone: 2334 // __block variables need to have the rhs evaluated first, plus 2335 // this should improve codegen just a little. 2336 RHS = Visit(E->getRHS()); 2337 LHS = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store); 2338 2339 // Store the value into the LHS. Bit-fields are handled specially 2340 // because the result is altered by the store, i.e., [C99 6.5.16p1] 2341 // 'An assignment expression has the value of the left operand after 2342 // the assignment...'. 2343 if (LHS.isBitField()) 2344 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, &RHS); 2345 else 2346 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS); 2347 } 2348 2349 // If the result is clearly ignored, return now. 2350 if (Ignore) 2351 return 0; 2352 2353 // The result of an assignment in C is the assigned r-value. 2354 if (!CGF.getContext().getLangOpts().CPlusPlus) 2355 return RHS; 2356 2357 // If the lvalue is non-volatile, return the computed value of the assignment. 2358 if (!LHS.isVolatileQualified()) 2359 return RHS; 2360 2361 // Otherwise, reload the value. 2362 return EmitLoadOfLValue(LHS); 2363 } 2364 2365 Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 2366 2367 // Perform vector logical and on comparisons with zero vectors. 2368 if (E->getType()->isVectorType()) { 2369 Value *LHS = Visit(E->getLHS()); 2370 Value *RHS = Visit(E->getRHS()); 2371 Value *Zero = llvm::ConstantAggregateZero::get(LHS->getType()); 2372 LHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, LHS, Zero, "cmp"); 2373 RHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, RHS, Zero, "cmp"); 2374 Value *And = Builder.CreateAnd(LHS, RHS); 2375 return Builder.CreateSExt(And, Zero->getType(), "sext"); 2376 } 2377 2378 llvm::Type *ResTy = ConvertType(E->getType()); 2379 2380 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 2381 // If we have 1 && X, just emit X without inserting the control flow. 2382 bool LHSCondVal; 2383 if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) { 2384 if (LHSCondVal) { // If we have 1 && X, just emit X. 2385 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2386 // ZExt result to int or bool. 2387 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 2388 } 2389 2390 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 2391 if (!CGF.ContainsLabel(E->getRHS())) 2392 return llvm::Constant::getNullValue(ResTy); 2393 } 2394 2395 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 2396 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 2397 2398 CodeGenFunction::ConditionalEvaluation eval(CGF); 2399 2400 // Branch on the LHS first. If it is false, go to the failure (cont) block. 2401 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 2402 2403 // Any edges into the ContBlock are now from an (indeterminate number of) 2404 // edges from this first condition. All of these values will be false. Start 2405 // setting up the PHI node in the Cont Block for this. 2406 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2, 2407 "", ContBlock); 2408 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 2409 PI != PE; ++PI) 2410 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 2411 2412 eval.begin(CGF); 2413 CGF.EmitBlock(RHSBlock); 2414 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2415 eval.end(CGF); 2416 2417 // Reaquire the RHS block, as there may be subblocks inserted. 2418 RHSBlock = Builder.GetInsertBlock(); 2419 2420 // Emit an unconditional branch from this block to ContBlock. Insert an entry 2421 // into the phi node for the edge with the value of RHSCond. 2422 if (CGF.getDebugInfo()) 2423 // There is no need to emit line number for unconditional branch. 2424 Builder.SetCurrentDebugLocation(llvm::DebugLoc()); 2425 CGF.EmitBlock(ContBlock); 2426 PN->addIncoming(RHSCond, RHSBlock); 2427 2428 // ZExt result to int. 2429 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); 2430 } 2431 2432 Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 2433 2434 // Perform vector logical or on comparisons with zero vectors. 2435 if (E->getType()->isVectorType()) { 2436 Value *LHS = Visit(E->getLHS()); 2437 Value *RHS = Visit(E->getRHS()); 2438 Value *Zero = llvm::ConstantAggregateZero::get(LHS->getType()); 2439 LHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, LHS, Zero, "cmp"); 2440 RHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, RHS, Zero, "cmp"); 2441 Value *Or = Builder.CreateOr(LHS, RHS); 2442 return Builder.CreateSExt(Or, Zero->getType(), "sext"); 2443 } 2444 2445 llvm::Type *ResTy = ConvertType(E->getType()); 2446 2447 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 2448 // If we have 0 || X, just emit X without inserting the control flow. 2449 bool LHSCondVal; 2450 if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) { 2451 if (!LHSCondVal) { // If we have 0 || X, just emit X. 2452 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2453 // ZExt result to int or bool. 2454 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 2455 } 2456 2457 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 2458 if (!CGF.ContainsLabel(E->getRHS())) 2459 return llvm::ConstantInt::get(ResTy, 1); 2460 } 2461 2462 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 2463 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 2464 2465 CodeGenFunction::ConditionalEvaluation eval(CGF); 2466 2467 // Branch on the LHS first. If it is true, go to the success (cont) block. 2468 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 2469 2470 // Any edges into the ContBlock are now from an (indeterminate number of) 2471 // edges from this first condition. All of these values will be true. Start 2472 // setting up the PHI node in the Cont Block for this. 2473 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2, 2474 "", ContBlock); 2475 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 2476 PI != PE; ++PI) 2477 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 2478 2479 eval.begin(CGF); 2480 2481 // Emit the RHS condition as a bool value. 2482 CGF.EmitBlock(RHSBlock); 2483 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2484 2485 eval.end(CGF); 2486 2487 // Reaquire the RHS block, as there may be subblocks inserted. 2488 RHSBlock = Builder.GetInsertBlock(); 2489 2490 // Emit an unconditional branch from this block to ContBlock. Insert an entry 2491 // into the phi node for the edge with the value of RHSCond. 2492 CGF.EmitBlock(ContBlock); 2493 PN->addIncoming(RHSCond, RHSBlock); 2494 2495 // ZExt result to int. 2496 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 2497 } 2498 2499 Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 2500 CGF.EmitIgnoredExpr(E->getLHS()); 2501 CGF.EnsureInsertPoint(); 2502 return Visit(E->getRHS()); 2503 } 2504 2505 //===----------------------------------------------------------------------===// 2506 // Other Operators 2507 //===----------------------------------------------------------------------===// 2508 2509 /// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 2510 /// expression is cheap enough and side-effect-free enough to evaluate 2511 /// unconditionally instead of conditionally. This is used to convert control 2512 /// flow into selects in some cases. 2513 static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 2514 CodeGenFunction &CGF) { 2515 E = E->IgnoreParens(); 2516 2517 // Anything that is an integer or floating point constant is fine. 2518 if (E->isConstantInitializer(CGF.getContext(), false)) 2519 return true; 2520 2521 // Non-volatile automatic variables too, to get "cond ? X : Y" where 2522 // X and Y are local variables. 2523 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 2524 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 2525 if (VD->hasLocalStorage() && !(CGF.getContext() 2526 .getCanonicalType(VD->getType()) 2527 .isVolatileQualified())) 2528 return true; 2529 2530 return false; 2531 } 2532 2533 2534 Value *ScalarExprEmitter:: 2535 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) { 2536 TestAndClearIgnoreResultAssign(); 2537 2538 // Bind the common expression if necessary. 2539 CodeGenFunction::OpaqueValueMapping binding(CGF, E); 2540 2541 Expr *condExpr = E->getCond(); 2542 Expr *lhsExpr = E->getTrueExpr(); 2543 Expr *rhsExpr = E->getFalseExpr(); 2544 2545 // If the condition constant folds and can be elided, try to avoid emitting 2546 // the condition and the dead arm. 2547 bool CondExprBool; 2548 if (CGF.ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) { 2549 Expr *live = lhsExpr, *dead = rhsExpr; 2550 if (!CondExprBool) std::swap(live, dead); 2551 2552 // If the dead side doesn't have labels we need, just emit the Live part. 2553 if (!CGF.ContainsLabel(dead)) { 2554 Value *Result = Visit(live); 2555 2556 // If the live part is a throw expression, it acts like it has a void 2557 // type, so evaluating it returns a null Value*. However, a conditional 2558 // with non-void type must return a non-null Value*. 2559 if (!Result && !E->getType()->isVoidType()) 2560 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType())); 2561 2562 return Result; 2563 } 2564 } 2565 2566 // OpenCL: If the condition is a vector, we can treat this condition like 2567 // the select function. 2568 if (CGF.getContext().getLangOpts().OpenCL 2569 && condExpr->getType()->isVectorType()) { 2570 llvm::Value *CondV = CGF.EmitScalarExpr(condExpr); 2571 llvm::Value *LHS = Visit(lhsExpr); 2572 llvm::Value *RHS = Visit(rhsExpr); 2573 2574 llvm::Type *condType = ConvertType(condExpr->getType()); 2575 llvm::VectorType *vecTy = cast<llvm::VectorType>(condType); 2576 2577 unsigned numElem = vecTy->getNumElements(); 2578 llvm::Type *elemType = vecTy->getElementType(); 2579 2580 llvm::Value *zeroVec = llvm::Constant::getNullValue(vecTy); 2581 llvm::Value *TestMSB = Builder.CreateICmpSLT(CondV, zeroVec); 2582 llvm::Value *tmp = Builder.CreateSExt(TestMSB, 2583 llvm::VectorType::get(elemType, 2584 numElem), 2585 "sext"); 2586 llvm::Value *tmp2 = Builder.CreateNot(tmp); 2587 2588 // Cast float to int to perform ANDs if necessary. 2589 llvm::Value *RHSTmp = RHS; 2590 llvm::Value *LHSTmp = LHS; 2591 bool wasCast = false; 2592 llvm::VectorType *rhsVTy = cast<llvm::VectorType>(RHS->getType()); 2593 if (rhsVTy->getElementType()->isFloatingPointTy()) { 2594 RHSTmp = Builder.CreateBitCast(RHS, tmp2->getType()); 2595 LHSTmp = Builder.CreateBitCast(LHS, tmp->getType()); 2596 wasCast = true; 2597 } 2598 2599 llvm::Value *tmp3 = Builder.CreateAnd(RHSTmp, tmp2); 2600 llvm::Value *tmp4 = Builder.CreateAnd(LHSTmp, tmp); 2601 llvm::Value *tmp5 = Builder.CreateOr(tmp3, tmp4, "cond"); 2602 if (wasCast) 2603 tmp5 = Builder.CreateBitCast(tmp5, RHS->getType()); 2604 2605 return tmp5; 2606 } 2607 2608 // If this is a really simple expression (like x ? 4 : 5), emit this as a 2609 // select instead of as control flow. We can only do this if it is cheap and 2610 // safe to evaluate the LHS and RHS unconditionally. 2611 if (isCheapEnoughToEvaluateUnconditionally(lhsExpr, CGF) && 2612 isCheapEnoughToEvaluateUnconditionally(rhsExpr, CGF)) { 2613 llvm::Value *CondV = CGF.EvaluateExprAsBool(condExpr); 2614 llvm::Value *LHS = Visit(lhsExpr); 2615 llvm::Value *RHS = Visit(rhsExpr); 2616 if (!LHS) { 2617 // If the conditional has void type, make sure we return a null Value*. 2618 assert(!RHS && "LHS and RHS types must match"); 2619 return 0; 2620 } 2621 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 2622 } 2623 2624 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 2625 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 2626 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 2627 2628 CodeGenFunction::ConditionalEvaluation eval(CGF); 2629 CGF.EmitBranchOnBoolExpr(condExpr, LHSBlock, RHSBlock); 2630 2631 CGF.EmitBlock(LHSBlock); 2632 eval.begin(CGF); 2633 Value *LHS = Visit(lhsExpr); 2634 eval.end(CGF); 2635 2636 LHSBlock = Builder.GetInsertBlock(); 2637 Builder.CreateBr(ContBlock); 2638 2639 CGF.EmitBlock(RHSBlock); 2640 eval.begin(CGF); 2641 Value *RHS = Visit(rhsExpr); 2642 eval.end(CGF); 2643 2644 RHSBlock = Builder.GetInsertBlock(); 2645 CGF.EmitBlock(ContBlock); 2646 2647 // If the LHS or RHS is a throw expression, it will be legitimately null. 2648 if (!LHS) 2649 return RHS; 2650 if (!RHS) 2651 return LHS; 2652 2653 // Create a PHI node for the real part. 2654 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), 2, "cond"); 2655 PN->addIncoming(LHS, LHSBlock); 2656 PN->addIncoming(RHS, RHSBlock); 2657 return PN; 2658 } 2659 2660 Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 2661 return Visit(E->getChosenSubExpr(CGF.getContext())); 2662 } 2663 2664 Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 2665 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 2666 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 2667 2668 // If EmitVAArg fails, we fall back to the LLVM instruction. 2669 if (!ArgPtr) 2670 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 2671 2672 // FIXME Volatility. 2673 return Builder.CreateLoad(ArgPtr); 2674 } 2675 2676 Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *block) { 2677 return CGF.EmitBlockLiteral(block); 2678 } 2679 2680 Value *ScalarExprEmitter::VisitAsTypeExpr(AsTypeExpr *E) { 2681 Value *Src = CGF.EmitScalarExpr(E->getSrcExpr()); 2682 llvm::Type *DstTy = ConvertType(E->getType()); 2683 2684 // Going from vec4->vec3 or vec3->vec4 is a special case and requires 2685 // a shuffle vector instead of a bitcast. 2686 llvm::Type *SrcTy = Src->getType(); 2687 if (isa<llvm::VectorType>(DstTy) && isa<llvm::VectorType>(SrcTy)) { 2688 unsigned numElementsDst = cast<llvm::VectorType>(DstTy)->getNumElements(); 2689 unsigned numElementsSrc = cast<llvm::VectorType>(SrcTy)->getNumElements(); 2690 if ((numElementsDst == 3 && numElementsSrc == 4) 2691 || (numElementsDst == 4 && numElementsSrc == 3)) { 2692 2693 2694 // In the case of going from int4->float3, a bitcast is needed before 2695 // doing a shuffle. 2696 llvm::Type *srcElemTy = 2697 cast<llvm::VectorType>(SrcTy)->getElementType(); 2698 llvm::Type *dstElemTy = 2699 cast<llvm::VectorType>(DstTy)->getElementType(); 2700 2701 if ((srcElemTy->isIntegerTy() && dstElemTy->isFloatTy()) 2702 || (srcElemTy->isFloatTy() && dstElemTy->isIntegerTy())) { 2703 // Create a float type of the same size as the source or destination. 2704 llvm::VectorType *newSrcTy = llvm::VectorType::get(dstElemTy, 2705 numElementsSrc); 2706 2707 Src = Builder.CreateBitCast(Src, newSrcTy, "astypeCast"); 2708 } 2709 2710 llvm::Value *UnV = llvm::UndefValue::get(Src->getType()); 2711 2712 SmallVector<llvm::Constant*, 3> Args; 2713 Args.push_back(Builder.getInt32(0)); 2714 Args.push_back(Builder.getInt32(1)); 2715 Args.push_back(Builder.getInt32(2)); 2716 2717 if (numElementsDst == 4) 2718 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 2719 2720 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 2721 2722 return Builder.CreateShuffleVector(Src, UnV, Mask, "astype"); 2723 } 2724 } 2725 2726 return Builder.CreateBitCast(Src, DstTy, "astype"); 2727 } 2728 2729 Value *ScalarExprEmitter::VisitAtomicExpr(AtomicExpr *E) { 2730 return CGF.EmitAtomicExpr(E).getScalarVal(); 2731 } 2732 2733 //===----------------------------------------------------------------------===// 2734 // Entry Point into this File 2735 //===----------------------------------------------------------------------===// 2736 2737 /// EmitScalarExpr - Emit the computation of the specified expression of scalar 2738 /// type, ignoring the result. 2739 Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 2740 assert(E && !hasAggregateLLVMType(E->getType()) && 2741 "Invalid scalar expression to emit"); 2742 2743 if (isa<CXXDefaultArgExpr>(E)) 2744 disableDebugInfo(); 2745 Value *V = ScalarExprEmitter(*this, IgnoreResultAssign) 2746 .Visit(const_cast<Expr*>(E)); 2747 if (isa<CXXDefaultArgExpr>(E)) 2748 enableDebugInfo(); 2749 return V; 2750 } 2751 2752 /// EmitScalarConversion - Emit a conversion from the specified type to the 2753 /// specified destination type, both of which are LLVM scalar types. 2754 Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 2755 QualType DstTy) { 2756 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 2757 "Invalid scalar expression to emit"); 2758 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 2759 } 2760 2761 /// EmitComplexToScalarConversion - Emit a conversion from the specified complex 2762 /// type to the specified destination type, where the destination type is an 2763 /// LLVM scalar type. 2764 Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 2765 QualType SrcTy, 2766 QualType DstTy) { 2767 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 2768 "Invalid complex -> scalar conversion"); 2769 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 2770 DstTy); 2771 } 2772 2773 2774 llvm::Value *CodeGenFunction:: 2775 EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 2776 bool isInc, bool isPre) { 2777 return ScalarExprEmitter(*this).EmitScalarPrePostIncDec(E, LV, isInc, isPre); 2778 } 2779 2780 LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) { 2781 llvm::Value *V; 2782 // object->isa or (*object).isa 2783 // Generate code as for: *(Class*)object 2784 // build Class* type 2785 llvm::Type *ClassPtrTy = ConvertType(E->getType()); 2786 2787 Expr *BaseExpr = E->getBase(); 2788 if (BaseExpr->isRValue()) { 2789 V = CreateMemTemp(E->getType(), "resval"); 2790 llvm::Value *Src = EmitScalarExpr(BaseExpr); 2791 Builder.CreateStore(Src, V); 2792 V = ScalarExprEmitter(*this).EmitLoadOfLValue( 2793 MakeNaturalAlignAddrLValue(V, E->getType())); 2794 } else { 2795 if (E->isArrow()) 2796 V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr); 2797 else 2798 V = EmitLValue(BaseExpr).getAddress(); 2799 } 2800 2801 // build Class* type 2802 ClassPtrTy = ClassPtrTy->getPointerTo(); 2803 V = Builder.CreateBitCast(V, ClassPtrTy); 2804 return MakeNaturalAlignAddrLValue(V, E->getType()); 2805 } 2806 2807 2808 LValue CodeGenFunction::EmitCompoundAssignmentLValue( 2809 const CompoundAssignOperator *E) { 2810 ScalarExprEmitter Scalar(*this); 2811 Value *Result = 0; 2812 switch (E->getOpcode()) { 2813 #define COMPOUND_OP(Op) \ 2814 case BO_##Op##Assign: \ 2815 return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \ 2816 Result) 2817 COMPOUND_OP(Mul); 2818 COMPOUND_OP(Div); 2819 COMPOUND_OP(Rem); 2820 COMPOUND_OP(Add); 2821 COMPOUND_OP(Sub); 2822 COMPOUND_OP(Shl); 2823 COMPOUND_OP(Shr); 2824 COMPOUND_OP(And); 2825 COMPOUND_OP(Xor); 2826 COMPOUND_OP(Or); 2827 #undef COMPOUND_OP 2828 2829 case BO_PtrMemD: 2830 case BO_PtrMemI: 2831 case BO_Mul: 2832 case BO_Div: 2833 case BO_Rem: 2834 case BO_Add: 2835 case BO_Sub: 2836 case BO_Shl: 2837 case BO_Shr: 2838 case BO_LT: 2839 case BO_GT: 2840 case BO_LE: 2841 case BO_GE: 2842 case BO_EQ: 2843 case BO_NE: 2844 case BO_And: 2845 case BO_Xor: 2846 case BO_Or: 2847 case BO_LAnd: 2848 case BO_LOr: 2849 case BO_Assign: 2850 case BO_Comma: 2851 llvm_unreachable("Not valid compound assignment operators"); 2852 } 2853 2854 llvm_unreachable("Unhandled compound assignment operator"); 2855 } 2856