CGExprScalar.cpp revision 252723
1//===--- CGExprScalar.cpp - Emit LLVM Code for Scalar Exprs ---------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This contains code to emit Expr nodes with scalar LLVM types as LLVM code. 11// 12//===----------------------------------------------------------------------===// 13 14#include "CodeGenFunction.h" 15#include "CGCXXABI.h" 16#include "CGDebugInfo.h" 17#include "CGObjCRuntime.h" 18#include "CodeGenModule.h" 19#include "clang/AST/ASTContext.h" 20#include "clang/AST/DeclObjC.h" 21#include "clang/AST/RecordLayout.h" 22#include "clang/AST/StmtVisitor.h" 23#include "clang/Basic/TargetInfo.h" 24#include "clang/Frontend/CodeGenOptions.h" 25#include "llvm/IR/Constants.h" 26#include "llvm/IR/DataLayout.h" 27#include "llvm/IR/Function.h" 28#include "llvm/IR/GlobalVariable.h" 29#include "llvm/IR/Intrinsics.h" 30#include "llvm/IR/Module.h" 31#include "llvm/Support/CFG.h" 32#include <cstdarg> 33 34using namespace clang; 35using namespace CodeGen; 36using llvm::Value; 37 38//===----------------------------------------------------------------------===// 39// Scalar Expression Emitter 40//===----------------------------------------------------------------------===// 41 42namespace { 43struct BinOpInfo { 44 Value *LHS; 45 Value *RHS; 46 QualType Ty; // Computation Type. 47 BinaryOperator::Opcode Opcode; // Opcode of BinOp to perform 48 bool FPContractable; 49 const Expr *E; // Entire expr, for error unsupported. May not be binop. 50}; 51 52static bool MustVisitNullValue(const Expr *E) { 53 // If a null pointer expression's type is the C++0x nullptr_t, then 54 // it's not necessarily a simple constant and it must be evaluated 55 // for its potential side effects. 56 return E->getType()->isNullPtrType(); 57} 58 59class ScalarExprEmitter 60 : public StmtVisitor<ScalarExprEmitter, Value*> { 61 CodeGenFunction &CGF; 62 CGBuilderTy &Builder; 63 bool IgnoreResultAssign; 64 llvm::LLVMContext &VMContext; 65public: 66 67 ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false) 68 : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira), 69 VMContext(cgf.getLLVMContext()) { 70 } 71 72 //===--------------------------------------------------------------------===// 73 // Utilities 74 //===--------------------------------------------------------------------===// 75 76 bool TestAndClearIgnoreResultAssign() { 77 bool I = IgnoreResultAssign; 78 IgnoreResultAssign = false; 79 return I; 80 } 81 82 llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); } 83 LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); } 84 LValue EmitCheckedLValue(const Expr *E, CodeGenFunction::TypeCheckKind TCK) { 85 return CGF.EmitCheckedLValue(E, TCK); 86 } 87 88 void EmitBinOpCheck(Value *Check, const BinOpInfo &Info); 89 90 Value *EmitLoadOfLValue(LValue LV) { 91 return CGF.EmitLoadOfLValue(LV).getScalarVal(); 92 } 93 94 /// EmitLoadOfLValue - Given an expression with complex type that represents a 95 /// value l-value, this method emits the address of the l-value, then loads 96 /// and returns the result. 97 Value *EmitLoadOfLValue(const Expr *E) { 98 return EmitLoadOfLValue(EmitCheckedLValue(E, CodeGenFunction::TCK_Load)); 99 } 100 101 /// EmitConversionToBool - Convert the specified expression value to a 102 /// boolean (i1) truth value. This is equivalent to "Val != 0". 103 Value *EmitConversionToBool(Value *Src, QualType DstTy); 104 105 /// \brief Emit a check that a conversion to or from a floating-point type 106 /// does not overflow. 107 void EmitFloatConversionCheck(Value *OrigSrc, QualType OrigSrcType, 108 Value *Src, QualType SrcType, 109 QualType DstType, llvm::Type *DstTy); 110 111 /// EmitScalarConversion - Emit a conversion from the specified type to the 112 /// specified destination type, both of which are LLVM scalar types. 113 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); 114 115 /// EmitComplexToScalarConversion - Emit a conversion from the specified 116 /// complex type to the specified destination type, where the destination type 117 /// is an LLVM scalar type. 118 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 119 QualType SrcTy, QualType DstTy); 120 121 /// EmitNullValue - Emit a value that corresponds to null for the given type. 122 Value *EmitNullValue(QualType Ty); 123 124 /// EmitFloatToBoolConversion - Perform an FP to boolean conversion. 125 Value *EmitFloatToBoolConversion(Value *V) { 126 // Compare against 0.0 for fp scalars. 127 llvm::Value *Zero = llvm::Constant::getNullValue(V->getType()); 128 return Builder.CreateFCmpUNE(V, Zero, "tobool"); 129 } 130 131 /// EmitPointerToBoolConversion - Perform a pointer to boolean conversion. 132 Value *EmitPointerToBoolConversion(Value *V) { 133 Value *Zero = llvm::ConstantPointerNull::get( 134 cast<llvm::PointerType>(V->getType())); 135 return Builder.CreateICmpNE(V, Zero, "tobool"); 136 } 137 138 Value *EmitIntToBoolConversion(Value *V) { 139 // Because of the type rules of C, we often end up computing a 140 // logical value, then zero extending it to int, then wanting it 141 // as a logical value again. Optimize this common case. 142 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(V)) { 143 if (ZI->getOperand(0)->getType() == Builder.getInt1Ty()) { 144 Value *Result = ZI->getOperand(0); 145 // If there aren't any more uses, zap the instruction to save space. 146 // Note that there can be more uses, for example if this 147 // is the result of an assignment. 148 if (ZI->use_empty()) 149 ZI->eraseFromParent(); 150 return Result; 151 } 152 } 153 154 return Builder.CreateIsNotNull(V, "tobool"); 155 } 156 157 //===--------------------------------------------------------------------===// 158 // Visitor Methods 159 //===--------------------------------------------------------------------===// 160 161 Value *Visit(Expr *E) { 162 return StmtVisitor<ScalarExprEmitter, Value*>::Visit(E); 163 } 164 165 Value *VisitStmt(Stmt *S) { 166 S->dump(CGF.getContext().getSourceManager()); 167 llvm_unreachable("Stmt can't have complex result type!"); 168 } 169 Value *VisitExpr(Expr *S); 170 171 Value *VisitParenExpr(ParenExpr *PE) { 172 return Visit(PE->getSubExpr()); 173 } 174 Value *VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) { 175 return Visit(E->getReplacement()); 176 } 177 Value *VisitGenericSelectionExpr(GenericSelectionExpr *GE) { 178 return Visit(GE->getResultExpr()); 179 } 180 181 // Leaves. 182 Value *VisitIntegerLiteral(const IntegerLiteral *E) { 183 return Builder.getInt(E->getValue()); 184 } 185 Value *VisitFloatingLiteral(const FloatingLiteral *E) { 186 return llvm::ConstantFP::get(VMContext, E->getValue()); 187 } 188 Value *VisitCharacterLiteral(const CharacterLiteral *E) { 189 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 190 } 191 Value *VisitObjCBoolLiteralExpr(const ObjCBoolLiteralExpr *E) { 192 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 193 } 194 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 195 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 196 } 197 Value *VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) { 198 return EmitNullValue(E->getType()); 199 } 200 Value *VisitGNUNullExpr(const GNUNullExpr *E) { 201 return EmitNullValue(E->getType()); 202 } 203 Value *VisitOffsetOfExpr(OffsetOfExpr *E); 204 Value *VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E); 205 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 206 llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel()); 207 return Builder.CreateBitCast(V, ConvertType(E->getType())); 208 } 209 210 Value *VisitSizeOfPackExpr(SizeOfPackExpr *E) { 211 return llvm::ConstantInt::get(ConvertType(E->getType()),E->getPackLength()); 212 } 213 214 Value *VisitPseudoObjectExpr(PseudoObjectExpr *E) { 215 return CGF.EmitPseudoObjectRValue(E).getScalarVal(); 216 } 217 218 Value *VisitOpaqueValueExpr(OpaqueValueExpr *E) { 219 if (E->isGLValue()) 220 return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E)); 221 222 // Otherwise, assume the mapping is the scalar directly. 223 return CGF.getOpaqueRValueMapping(E).getScalarVal(); 224 } 225 226 // l-values. 227 Value *VisitDeclRefExpr(DeclRefExpr *E) { 228 if (CodeGenFunction::ConstantEmission result = CGF.tryEmitAsConstant(E)) { 229 if (result.isReference()) 230 return EmitLoadOfLValue(result.getReferenceLValue(CGF, E)); 231 return result.getValue(); 232 } 233 return EmitLoadOfLValue(E); 234 } 235 236 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 237 return CGF.EmitObjCSelectorExpr(E); 238 } 239 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 240 return CGF.EmitObjCProtocolExpr(E); 241 } 242 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 243 return EmitLoadOfLValue(E); 244 } 245 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 246 if (E->getMethodDecl() && 247 E->getMethodDecl()->getResultType()->isReferenceType()) 248 return EmitLoadOfLValue(E); 249 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 250 } 251 252 Value *VisitObjCIsaExpr(ObjCIsaExpr *E) { 253 LValue LV = CGF.EmitObjCIsaExpr(E); 254 Value *V = CGF.EmitLoadOfLValue(LV).getScalarVal(); 255 return V; 256 } 257 258 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 259 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 260 Value *VisitMemberExpr(MemberExpr *E); 261 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 262 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 263 return EmitLoadOfLValue(E); 264 } 265 266 Value *VisitInitListExpr(InitListExpr *E); 267 268 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { 269 return EmitNullValue(E->getType()); 270 } 271 Value *VisitExplicitCastExpr(ExplicitCastExpr *E) { 272 if (E->getType()->isVariablyModifiedType()) 273 CGF.EmitVariablyModifiedType(E->getType()); 274 return VisitCastExpr(E); 275 } 276 Value *VisitCastExpr(CastExpr *E); 277 278 Value *VisitCallExpr(const CallExpr *E) { 279 if (E->getCallReturnType()->isReferenceType()) 280 return EmitLoadOfLValue(E); 281 282 return CGF.EmitCallExpr(E).getScalarVal(); 283 } 284 285 Value *VisitStmtExpr(const StmtExpr *E); 286 287 // Unary Operators. 288 Value *VisitUnaryPostDec(const UnaryOperator *E) { 289 LValue LV = EmitLValue(E->getSubExpr()); 290 return EmitScalarPrePostIncDec(E, LV, false, false); 291 } 292 Value *VisitUnaryPostInc(const UnaryOperator *E) { 293 LValue LV = EmitLValue(E->getSubExpr()); 294 return EmitScalarPrePostIncDec(E, LV, true, false); 295 } 296 Value *VisitUnaryPreDec(const UnaryOperator *E) { 297 LValue LV = EmitLValue(E->getSubExpr()); 298 return EmitScalarPrePostIncDec(E, LV, false, true); 299 } 300 Value *VisitUnaryPreInc(const UnaryOperator *E) { 301 LValue LV = EmitLValue(E->getSubExpr()); 302 return EmitScalarPrePostIncDec(E, LV, true, true); 303 } 304 305 llvm::Value *EmitAddConsiderOverflowBehavior(const UnaryOperator *E, 306 llvm::Value *InVal, 307 llvm::Value *NextVal, 308 bool IsInc); 309 310 llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 311 bool isInc, bool isPre); 312 313 314 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 315 if (isa<MemberPointerType>(E->getType())) // never sugared 316 return CGF.CGM.getMemberPointerConstant(E); 317 318 return EmitLValue(E->getSubExpr()).getAddress(); 319 } 320 Value *VisitUnaryDeref(const UnaryOperator *E) { 321 if (E->getType()->isVoidType()) 322 return Visit(E->getSubExpr()); // the actual value should be unused 323 return EmitLoadOfLValue(E); 324 } 325 Value *VisitUnaryPlus(const UnaryOperator *E) { 326 // This differs from gcc, though, most likely due to a bug in gcc. 327 TestAndClearIgnoreResultAssign(); 328 return Visit(E->getSubExpr()); 329 } 330 Value *VisitUnaryMinus (const UnaryOperator *E); 331 Value *VisitUnaryNot (const UnaryOperator *E); 332 Value *VisitUnaryLNot (const UnaryOperator *E); 333 Value *VisitUnaryReal (const UnaryOperator *E); 334 Value *VisitUnaryImag (const UnaryOperator *E); 335 Value *VisitUnaryExtension(const UnaryOperator *E) { 336 return Visit(E->getSubExpr()); 337 } 338 339 // C++ 340 Value *VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E) { 341 return EmitLoadOfLValue(E); 342 } 343 344 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 345 return Visit(DAE->getExpr()); 346 } 347 Value *VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) { 348 CodeGenFunction::CXXDefaultInitExprScope Scope(CGF); 349 return Visit(DIE->getExpr()); 350 } 351 Value *VisitCXXThisExpr(CXXThisExpr *TE) { 352 return CGF.LoadCXXThis(); 353 } 354 355 Value *VisitExprWithCleanups(ExprWithCleanups *E) { 356 CGF.enterFullExpression(E); 357 CodeGenFunction::RunCleanupsScope Scope(CGF); 358 return Visit(E->getSubExpr()); 359 } 360 Value *VisitCXXNewExpr(const CXXNewExpr *E) { 361 return CGF.EmitCXXNewExpr(E); 362 } 363 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { 364 CGF.EmitCXXDeleteExpr(E); 365 return 0; 366 } 367 Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) { 368 return Builder.getInt1(E->getValue()); 369 } 370 371 Value *VisitBinaryTypeTraitExpr(const BinaryTypeTraitExpr *E) { 372 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 373 } 374 375 Value *VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) { 376 return llvm::ConstantInt::get(Builder.getInt32Ty(), E->getValue()); 377 } 378 379 Value *VisitExpressionTraitExpr(const ExpressionTraitExpr *E) { 380 return llvm::ConstantInt::get(Builder.getInt1Ty(), E->getValue()); 381 } 382 383 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { 384 // C++ [expr.pseudo]p1: 385 // The result shall only be used as the operand for the function call 386 // operator (), and the result of such a call has type void. The only 387 // effect is the evaluation of the postfix-expression before the dot or 388 // arrow. 389 CGF.EmitScalarExpr(E->getBase()); 390 return 0; 391 } 392 393 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { 394 return EmitNullValue(E->getType()); 395 } 396 397 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { 398 CGF.EmitCXXThrowExpr(E); 399 return 0; 400 } 401 402 Value *VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) { 403 return Builder.getInt1(E->getValue()); 404 } 405 406 // Binary Operators. 407 Value *EmitMul(const BinOpInfo &Ops) { 408 if (Ops.Ty->isSignedIntegerOrEnumerationType()) { 409 switch (CGF.getLangOpts().getSignedOverflowBehavior()) { 410 case LangOptions::SOB_Defined: 411 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 412 case LangOptions::SOB_Undefined: 413 if (!CGF.SanOpts->SignedIntegerOverflow) 414 return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul"); 415 // Fall through. 416 case LangOptions::SOB_Trapping: 417 return EmitOverflowCheckedBinOp(Ops); 418 } 419 } 420 421 if (Ops.Ty->isUnsignedIntegerType() && CGF.SanOpts->UnsignedIntegerOverflow) 422 return EmitOverflowCheckedBinOp(Ops); 423 424 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 425 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 426 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 427 } 428 /// Create a binary op that checks for overflow. 429 /// Currently only supports +, - and *. 430 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 431 432 // Check for undefined division and modulus behaviors. 433 void EmitUndefinedBehaviorIntegerDivAndRemCheck(const BinOpInfo &Ops, 434 llvm::Value *Zero,bool isDiv); 435 // Common helper for getting how wide LHS of shift is. 436 static Value *GetWidthMinusOneValue(Value* LHS,Value* RHS); 437 Value *EmitDiv(const BinOpInfo &Ops); 438 Value *EmitRem(const BinOpInfo &Ops); 439 Value *EmitAdd(const BinOpInfo &Ops); 440 Value *EmitSub(const BinOpInfo &Ops); 441 Value *EmitShl(const BinOpInfo &Ops); 442 Value *EmitShr(const BinOpInfo &Ops); 443 Value *EmitAnd(const BinOpInfo &Ops) { 444 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 445 } 446 Value *EmitXor(const BinOpInfo &Ops) { 447 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 448 } 449 Value *EmitOr (const BinOpInfo &Ops) { 450 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 451 } 452 453 BinOpInfo EmitBinOps(const BinaryOperator *E); 454 LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E, 455 Value *(ScalarExprEmitter::*F)(const BinOpInfo &), 456 Value *&Result); 457 458 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 459 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 460 461 // Binary operators and binary compound assignment operators. 462#define HANDLEBINOP(OP) \ 463 Value *VisitBin ## OP(const BinaryOperator *E) { \ 464 return Emit ## OP(EmitBinOps(E)); \ 465 } \ 466 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 467 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 468 } 469 HANDLEBINOP(Mul) 470 HANDLEBINOP(Div) 471 HANDLEBINOP(Rem) 472 HANDLEBINOP(Add) 473 HANDLEBINOP(Sub) 474 HANDLEBINOP(Shl) 475 HANDLEBINOP(Shr) 476 HANDLEBINOP(And) 477 HANDLEBINOP(Xor) 478 HANDLEBINOP(Or) 479#undef HANDLEBINOP 480 481 // Comparisons. 482 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 483 unsigned SICmpOpc, unsigned FCmpOpc); 484#define VISITCOMP(CODE, UI, SI, FP) \ 485 Value *VisitBin##CODE(const BinaryOperator *E) { \ 486 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 487 llvm::FCmpInst::FP); } 488 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT) 489 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT) 490 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE) 491 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE) 492 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ) 493 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE) 494#undef VISITCOMP 495 496 Value *VisitBinAssign (const BinaryOperator *E); 497 498 Value *VisitBinLAnd (const BinaryOperator *E); 499 Value *VisitBinLOr (const BinaryOperator *E); 500 Value *VisitBinComma (const BinaryOperator *E); 501 502 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } 503 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); } 504 505 // Other Operators. 506 Value *VisitBlockExpr(const BlockExpr *BE); 507 Value *VisitAbstractConditionalOperator(const AbstractConditionalOperator *); 508 Value *VisitChooseExpr(ChooseExpr *CE); 509 Value *VisitVAArgExpr(VAArgExpr *VE); 510 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 511 return CGF.EmitObjCStringLiteral(E); 512 } 513 Value *VisitObjCBoxedExpr(ObjCBoxedExpr *E) { 514 return CGF.EmitObjCBoxedExpr(E); 515 } 516 Value *VisitObjCArrayLiteral(ObjCArrayLiteral *E) { 517 return CGF.EmitObjCArrayLiteral(E); 518 } 519 Value *VisitObjCDictionaryLiteral(ObjCDictionaryLiteral *E) { 520 return CGF.EmitObjCDictionaryLiteral(E); 521 } 522 Value *VisitAsTypeExpr(AsTypeExpr *CE); 523 Value *VisitAtomicExpr(AtomicExpr *AE); 524}; 525} // end anonymous namespace. 526 527//===----------------------------------------------------------------------===// 528// Utilities 529//===----------------------------------------------------------------------===// 530 531/// EmitConversionToBool - Convert the specified expression value to a 532/// boolean (i1) truth value. This is equivalent to "Val != 0". 533Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 534 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs"); 535 536 if (SrcType->isRealFloatingType()) 537 return EmitFloatToBoolConversion(Src); 538 539 if (const MemberPointerType *MPT = dyn_cast<MemberPointerType>(SrcType)) 540 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, Src, MPT); 541 542 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 543 "Unknown scalar type to convert"); 544 545 if (isa<llvm::IntegerType>(Src->getType())) 546 return EmitIntToBoolConversion(Src); 547 548 assert(isa<llvm::PointerType>(Src->getType())); 549 return EmitPointerToBoolConversion(Src); 550} 551 552void ScalarExprEmitter::EmitFloatConversionCheck(Value *OrigSrc, 553 QualType OrigSrcType, 554 Value *Src, QualType SrcType, 555 QualType DstType, 556 llvm::Type *DstTy) { 557 using llvm::APFloat; 558 using llvm::APSInt; 559 560 llvm::Type *SrcTy = Src->getType(); 561 562 llvm::Value *Check = 0; 563 if (llvm::IntegerType *IntTy = dyn_cast<llvm::IntegerType>(SrcTy)) { 564 // Integer to floating-point. This can fail for unsigned short -> __half 565 // or unsigned __int128 -> float. 566 assert(DstType->isFloatingType()); 567 bool SrcIsUnsigned = OrigSrcType->isUnsignedIntegerOrEnumerationType(); 568 569 APFloat LargestFloat = 570 APFloat::getLargest(CGF.getContext().getFloatTypeSemantics(DstType)); 571 APSInt LargestInt(IntTy->getBitWidth(), SrcIsUnsigned); 572 573 bool IsExact; 574 if (LargestFloat.convertToInteger(LargestInt, APFloat::rmTowardZero, 575 &IsExact) != APFloat::opOK) 576 // The range of representable values of this floating point type includes 577 // all values of this integer type. Don't need an overflow check. 578 return; 579 580 llvm::Value *Max = llvm::ConstantInt::get(VMContext, LargestInt); 581 if (SrcIsUnsigned) 582 Check = Builder.CreateICmpULE(Src, Max); 583 else { 584 llvm::Value *Min = llvm::ConstantInt::get(VMContext, -LargestInt); 585 llvm::Value *GE = Builder.CreateICmpSGE(Src, Min); 586 llvm::Value *LE = Builder.CreateICmpSLE(Src, Max); 587 Check = Builder.CreateAnd(GE, LE); 588 } 589 } else { 590 const llvm::fltSemantics &SrcSema = 591 CGF.getContext().getFloatTypeSemantics(OrigSrcType); 592 if (isa<llvm::IntegerType>(DstTy)) { 593 // Floating-point to integer. This has undefined behavior if the source is 594 // +-Inf, NaN, or doesn't fit into the destination type (after truncation 595 // to an integer). 596 unsigned Width = CGF.getContext().getIntWidth(DstType); 597 bool Unsigned = DstType->isUnsignedIntegerOrEnumerationType(); 598 599 APSInt Min = APSInt::getMinValue(Width, Unsigned); 600 APFloat MinSrc(SrcSema, APFloat::uninitialized); 601 if (MinSrc.convertFromAPInt(Min, !Unsigned, APFloat::rmTowardZero) & 602 APFloat::opOverflow) 603 // Don't need an overflow check for lower bound. Just check for 604 // -Inf/NaN. 605 MinSrc = APFloat::getInf(SrcSema, true); 606 else 607 // Find the largest value which is too small to represent (before 608 // truncation toward zero). 609 MinSrc.subtract(APFloat(SrcSema, 1), APFloat::rmTowardNegative); 610 611 APSInt Max = APSInt::getMaxValue(Width, Unsigned); 612 APFloat MaxSrc(SrcSema, APFloat::uninitialized); 613 if (MaxSrc.convertFromAPInt(Max, !Unsigned, APFloat::rmTowardZero) & 614 APFloat::opOverflow) 615 // Don't need an overflow check for upper bound. Just check for 616 // +Inf/NaN. 617 MaxSrc = APFloat::getInf(SrcSema, false); 618 else 619 // Find the smallest value which is too large to represent (before 620 // truncation toward zero). 621 MaxSrc.add(APFloat(SrcSema, 1), APFloat::rmTowardPositive); 622 623 // If we're converting from __half, convert the range to float to match 624 // the type of src. 625 if (OrigSrcType->isHalfType()) { 626 const llvm::fltSemantics &Sema = 627 CGF.getContext().getFloatTypeSemantics(SrcType); 628 bool IsInexact; 629 MinSrc.convert(Sema, APFloat::rmTowardZero, &IsInexact); 630 MaxSrc.convert(Sema, APFloat::rmTowardZero, &IsInexact); 631 } 632 633 llvm::Value *GE = 634 Builder.CreateFCmpOGT(Src, llvm::ConstantFP::get(VMContext, MinSrc)); 635 llvm::Value *LE = 636 Builder.CreateFCmpOLT(Src, llvm::ConstantFP::get(VMContext, MaxSrc)); 637 Check = Builder.CreateAnd(GE, LE); 638 } else { 639 // FIXME: Maybe split this sanitizer out from float-cast-overflow. 640 // 641 // Floating-point to floating-point. This has undefined behavior if the 642 // source is not in the range of representable values of the destination 643 // type. The C and C++ standards are spectacularly unclear here. We 644 // diagnose finite out-of-range conversions, but allow infinities and NaNs 645 // to convert to the corresponding value in the smaller type. 646 // 647 // C11 Annex F gives all such conversions defined behavior for IEC 60559 648 // conforming implementations. Unfortunately, LLVM's fptrunc instruction 649 // does not. 650 651 // Converting from a lower rank to a higher rank can never have 652 // undefined behavior, since higher-rank types must have a superset 653 // of values of lower-rank types. 654 if (CGF.getContext().getFloatingTypeOrder(OrigSrcType, DstType) != 1) 655 return; 656 657 assert(!OrigSrcType->isHalfType() && 658 "should not check conversion from __half, it has the lowest rank"); 659 660 const llvm::fltSemantics &DstSema = 661 CGF.getContext().getFloatTypeSemantics(DstType); 662 APFloat MinBad = APFloat::getLargest(DstSema, false); 663 APFloat MaxBad = APFloat::getInf(DstSema, false); 664 665 bool IsInexact; 666 MinBad.convert(SrcSema, APFloat::rmTowardZero, &IsInexact); 667 MaxBad.convert(SrcSema, APFloat::rmTowardZero, &IsInexact); 668 669 Value *AbsSrc = CGF.EmitNounwindRuntimeCall( 670 CGF.CGM.getIntrinsic(llvm::Intrinsic::fabs, Src->getType()), Src); 671 llvm::Value *GE = 672 Builder.CreateFCmpOGT(AbsSrc, llvm::ConstantFP::get(VMContext, MinBad)); 673 llvm::Value *LE = 674 Builder.CreateFCmpOLT(AbsSrc, llvm::ConstantFP::get(VMContext, MaxBad)); 675 Check = Builder.CreateNot(Builder.CreateAnd(GE, LE)); 676 } 677 } 678 679 // FIXME: Provide a SourceLocation. 680 llvm::Constant *StaticArgs[] = { 681 CGF.EmitCheckTypeDescriptor(OrigSrcType), 682 CGF.EmitCheckTypeDescriptor(DstType) 683 }; 684 CGF.EmitCheck(Check, "float_cast_overflow", StaticArgs, OrigSrc, 685 CodeGenFunction::CRK_Recoverable); 686} 687 688/// EmitScalarConversion - Emit a conversion from the specified type to the 689/// specified destination type, both of which are LLVM scalar types. 690Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 691 QualType DstType) { 692 SrcType = CGF.getContext().getCanonicalType(SrcType); 693 DstType = CGF.getContext().getCanonicalType(DstType); 694 if (SrcType == DstType) return Src; 695 696 if (DstType->isVoidType()) return 0; 697 698 llvm::Value *OrigSrc = Src; 699 QualType OrigSrcType = SrcType; 700 llvm::Type *SrcTy = Src->getType(); 701 702 // If casting to/from storage-only half FP, use special intrinsics. 703 if (SrcType->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) { 704 Src = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16), Src); 705 SrcType = CGF.getContext().FloatTy; 706 SrcTy = CGF.FloatTy; 707 } 708 709 // Handle conversions to bool first, they are special: comparisons against 0. 710 if (DstType->isBooleanType()) 711 return EmitConversionToBool(Src, SrcType); 712 713 llvm::Type *DstTy = ConvertType(DstType); 714 715 // Ignore conversions like int -> uint. 716 if (SrcTy == DstTy) 717 return Src; 718 719 // Handle pointer conversions next: pointers can only be converted to/from 720 // other pointers and integers. Check for pointer types in terms of LLVM, as 721 // some native types (like Obj-C id) may map to a pointer type. 722 if (isa<llvm::PointerType>(DstTy)) { 723 // The source value may be an integer, or a pointer. 724 if (isa<llvm::PointerType>(SrcTy)) 725 return Builder.CreateBitCast(Src, DstTy, "conv"); 726 727 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 728 // First, convert to the correct width so that we control the kind of 729 // extension. 730 llvm::Type *MiddleTy = CGF.IntPtrTy; 731 bool InputSigned = SrcType->isSignedIntegerOrEnumerationType(); 732 llvm::Value* IntResult = 733 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 734 // Then, cast to pointer. 735 return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); 736 } 737 738 if (isa<llvm::PointerType>(SrcTy)) { 739 // Must be an ptr to int cast. 740 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 741 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 742 } 743 744 // A scalar can be splatted to an extended vector of the same element type 745 if (DstType->isExtVectorType() && !SrcType->isVectorType()) { 746 // Cast the scalar to element type 747 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType(); 748 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 749 750 // Splat the element across to all elements 751 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 752 return Builder.CreateVectorSplat(NumElements, Elt, "splat"); 753 } 754 755 // Allow bitcast from vector to integer/fp of the same size. 756 if (isa<llvm::VectorType>(SrcTy) || 757 isa<llvm::VectorType>(DstTy)) 758 return Builder.CreateBitCast(Src, DstTy, "conv"); 759 760 // Finally, we have the arithmetic types: real int/float. 761 Value *Res = NULL; 762 llvm::Type *ResTy = DstTy; 763 764 // An overflowing conversion has undefined behavior if either the source type 765 // or the destination type is a floating-point type. 766 if (CGF.SanOpts->FloatCastOverflow && 767 (OrigSrcType->isFloatingType() || DstType->isFloatingType())) 768 EmitFloatConversionCheck(OrigSrc, OrigSrcType, Src, SrcType, DstType, 769 DstTy); 770 771 // Cast to half via float 772 if (DstType->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) 773 DstTy = CGF.FloatTy; 774 775 if (isa<llvm::IntegerType>(SrcTy)) { 776 bool InputSigned = SrcType->isSignedIntegerOrEnumerationType(); 777 if (isa<llvm::IntegerType>(DstTy)) 778 Res = Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 779 else if (InputSigned) 780 Res = Builder.CreateSIToFP(Src, DstTy, "conv"); 781 else 782 Res = Builder.CreateUIToFP(Src, DstTy, "conv"); 783 } else if (isa<llvm::IntegerType>(DstTy)) { 784 assert(SrcTy->isFloatingPointTy() && "Unknown real conversion"); 785 if (DstType->isSignedIntegerOrEnumerationType()) 786 Res = Builder.CreateFPToSI(Src, DstTy, "conv"); 787 else 788 Res = Builder.CreateFPToUI(Src, DstTy, "conv"); 789 } else { 790 assert(SrcTy->isFloatingPointTy() && DstTy->isFloatingPointTy() && 791 "Unknown real conversion"); 792 if (DstTy->getTypeID() < SrcTy->getTypeID()) 793 Res = Builder.CreateFPTrunc(Src, DstTy, "conv"); 794 else 795 Res = Builder.CreateFPExt(Src, DstTy, "conv"); 796 } 797 798 if (DstTy != ResTy) { 799 assert(ResTy->isIntegerTy(16) && "Only half FP requires extra conversion"); 800 Res = Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16), Res); 801 } 802 803 return Res; 804} 805 806/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 807/// type to the specified destination type, where the destination type is an 808/// LLVM scalar type. 809Value *ScalarExprEmitter:: 810EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 811 QualType SrcTy, QualType DstTy) { 812 // Get the source element type. 813 SrcTy = SrcTy->castAs<ComplexType>()->getElementType(); 814 815 // Handle conversions to bool first, they are special: comparisons against 0. 816 if (DstTy->isBooleanType()) { 817 // Complex != 0 -> (Real != 0) | (Imag != 0) 818 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 819 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 820 return Builder.CreateOr(Src.first, Src.second, "tobool"); 821 } 822 823 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 824 // the imaginary part of the complex value is discarded and the value of the 825 // real part is converted according to the conversion rules for the 826 // corresponding real type. 827 return EmitScalarConversion(Src.first, SrcTy, DstTy); 828} 829 830Value *ScalarExprEmitter::EmitNullValue(QualType Ty) { 831 return CGF.EmitFromMemory(CGF.CGM.EmitNullConstant(Ty), Ty); 832} 833 834/// \brief Emit a sanitization check for the given "binary" operation (which 835/// might actually be a unary increment which has been lowered to a binary 836/// operation). The check passes if \p Check, which is an \c i1, is \c true. 837void ScalarExprEmitter::EmitBinOpCheck(Value *Check, const BinOpInfo &Info) { 838 StringRef CheckName; 839 SmallVector<llvm::Constant *, 4> StaticData; 840 SmallVector<llvm::Value *, 2> DynamicData; 841 842 BinaryOperatorKind Opcode = Info.Opcode; 843 if (BinaryOperator::isCompoundAssignmentOp(Opcode)) 844 Opcode = BinaryOperator::getOpForCompoundAssignment(Opcode); 845 846 StaticData.push_back(CGF.EmitCheckSourceLocation(Info.E->getExprLoc())); 847 const UnaryOperator *UO = dyn_cast<UnaryOperator>(Info.E); 848 if (UO && UO->getOpcode() == UO_Minus) { 849 CheckName = "negate_overflow"; 850 StaticData.push_back(CGF.EmitCheckTypeDescriptor(UO->getType())); 851 DynamicData.push_back(Info.RHS); 852 } else { 853 if (BinaryOperator::isShiftOp(Opcode)) { 854 // Shift LHS negative or too large, or RHS out of bounds. 855 CheckName = "shift_out_of_bounds"; 856 const BinaryOperator *BO = cast<BinaryOperator>(Info.E); 857 StaticData.push_back( 858 CGF.EmitCheckTypeDescriptor(BO->getLHS()->getType())); 859 StaticData.push_back( 860 CGF.EmitCheckTypeDescriptor(BO->getRHS()->getType())); 861 } else if (Opcode == BO_Div || Opcode == BO_Rem) { 862 // Divide or modulo by zero, or signed overflow (eg INT_MAX / -1). 863 CheckName = "divrem_overflow"; 864 StaticData.push_back(CGF.EmitCheckTypeDescriptor(Info.Ty)); 865 } else { 866 // Signed arithmetic overflow (+, -, *). 867 switch (Opcode) { 868 case BO_Add: CheckName = "add_overflow"; break; 869 case BO_Sub: CheckName = "sub_overflow"; break; 870 case BO_Mul: CheckName = "mul_overflow"; break; 871 default: llvm_unreachable("unexpected opcode for bin op check"); 872 } 873 StaticData.push_back(CGF.EmitCheckTypeDescriptor(Info.Ty)); 874 } 875 DynamicData.push_back(Info.LHS); 876 DynamicData.push_back(Info.RHS); 877 } 878 879 CGF.EmitCheck(Check, CheckName, StaticData, DynamicData, 880 CodeGenFunction::CRK_Recoverable); 881} 882 883//===----------------------------------------------------------------------===// 884// Visitor Methods 885//===----------------------------------------------------------------------===// 886 887Value *ScalarExprEmitter::VisitExpr(Expr *E) { 888 CGF.ErrorUnsupported(E, "scalar expression"); 889 if (E->getType()->isVoidType()) 890 return 0; 891 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 892} 893 894Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 895 // Vector Mask Case 896 if (E->getNumSubExprs() == 2 || 897 (E->getNumSubExprs() == 3 && E->getExpr(2)->getType()->isVectorType())) { 898 Value *LHS = CGF.EmitScalarExpr(E->getExpr(0)); 899 Value *RHS = CGF.EmitScalarExpr(E->getExpr(1)); 900 Value *Mask; 901 902 llvm::VectorType *LTy = cast<llvm::VectorType>(LHS->getType()); 903 unsigned LHSElts = LTy->getNumElements(); 904 905 if (E->getNumSubExprs() == 3) { 906 Mask = CGF.EmitScalarExpr(E->getExpr(2)); 907 908 // Shuffle LHS & RHS into one input vector. 909 SmallVector<llvm::Constant*, 32> concat; 910 for (unsigned i = 0; i != LHSElts; ++i) { 911 concat.push_back(Builder.getInt32(2*i)); 912 concat.push_back(Builder.getInt32(2*i+1)); 913 } 914 915 Value* CV = llvm::ConstantVector::get(concat); 916 LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat"); 917 LHSElts *= 2; 918 } else { 919 Mask = RHS; 920 } 921 922 llvm::VectorType *MTy = cast<llvm::VectorType>(Mask->getType()); 923 llvm::Constant* EltMask; 924 925 // Treat vec3 like vec4. 926 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) 927 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 928 (1 << llvm::Log2_32(LHSElts+2))-1); 929 else if ((LHSElts == 3) && (E->getNumSubExprs() == 2)) 930 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 931 (1 << llvm::Log2_32(LHSElts+1))-1); 932 else 933 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 934 (1 << llvm::Log2_32(LHSElts))-1); 935 936 // Mask off the high bits of each shuffle index. 937 Value *MaskBits = llvm::ConstantVector::getSplat(MTy->getNumElements(), 938 EltMask); 939 Mask = Builder.CreateAnd(Mask, MaskBits, "mask"); 940 941 // newv = undef 942 // mask = mask & maskbits 943 // for each elt 944 // n = extract mask i 945 // x = extract val n 946 // newv = insert newv, x, i 947 llvm::VectorType *RTy = llvm::VectorType::get(LTy->getElementType(), 948 MTy->getNumElements()); 949 Value* NewV = llvm::UndefValue::get(RTy); 950 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) { 951 Value *IIndx = Builder.getInt32(i); 952 Value *Indx = Builder.CreateExtractElement(Mask, IIndx, "shuf_idx"); 953 Indx = Builder.CreateZExt(Indx, CGF.Int32Ty, "idx_zext"); 954 955 // Handle vec3 special since the index will be off by one for the RHS. 956 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) { 957 Value *cmpIndx, *newIndx; 958 cmpIndx = Builder.CreateICmpUGT(Indx, Builder.getInt32(3), 959 "cmp_shuf_idx"); 960 newIndx = Builder.CreateSub(Indx, Builder.getInt32(1), "shuf_idx_adj"); 961 Indx = Builder.CreateSelect(cmpIndx, newIndx, Indx, "sel_shuf_idx"); 962 } 963 Value *VExt = Builder.CreateExtractElement(LHS, Indx, "shuf_elt"); 964 NewV = Builder.CreateInsertElement(NewV, VExt, IIndx, "shuf_ins"); 965 } 966 return NewV; 967 } 968 969 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 970 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 971 972 // Handle vec3 special since the index will be off by one for the RHS. 973 llvm::VectorType *VTy = cast<llvm::VectorType>(V1->getType()); 974 SmallVector<llvm::Constant*, 32> indices; 975 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 976 unsigned Idx = E->getShuffleMaskIdx(CGF.getContext(), i-2); 977 if (VTy->getNumElements() == 3 && Idx > 3) 978 Idx -= 1; 979 indices.push_back(Builder.getInt32(Idx)); 980 } 981 982 Value *SV = llvm::ConstantVector::get(indices); 983 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 984} 985Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { 986 llvm::APSInt Value; 987 if (E->EvaluateAsInt(Value, CGF.getContext(), Expr::SE_AllowSideEffects)) { 988 if (E->isArrow()) 989 CGF.EmitScalarExpr(E->getBase()); 990 else 991 EmitLValue(E->getBase()); 992 return Builder.getInt(Value); 993 } 994 995 // Emit debug info for aggregate now, if it was delayed to reduce 996 // debug info size. 997 CGDebugInfo *DI = CGF.getDebugInfo(); 998 if (DI && 999 CGF.CGM.getCodeGenOpts().getDebugInfo() 1000 == CodeGenOptions::LimitedDebugInfo) { 1001 QualType PQTy = E->getBase()->IgnoreParenImpCasts()->getType(); 1002 if (const PointerType * PTy = dyn_cast<PointerType>(PQTy)) 1003 if (FieldDecl *M = dyn_cast<FieldDecl>(E->getMemberDecl())) 1004 DI->getOrCreateRecordType(PTy->getPointeeType(), 1005 M->getParent()->getLocation()); 1006 } 1007 return EmitLoadOfLValue(E); 1008} 1009 1010Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 1011 TestAndClearIgnoreResultAssign(); 1012 1013 // Emit subscript expressions in rvalue context's. For most cases, this just 1014 // loads the lvalue formed by the subscript expr. However, we have to be 1015 // careful, because the base of a vector subscript is occasionally an rvalue, 1016 // so we can't get it as an lvalue. 1017 if (!E->getBase()->getType()->isVectorType()) 1018 return EmitLoadOfLValue(E); 1019 1020 // Handle the vector case. The base must be a vector, the index must be an 1021 // integer value. 1022 Value *Base = Visit(E->getBase()); 1023 Value *Idx = Visit(E->getIdx()); 1024 QualType IdxTy = E->getIdx()->getType(); 1025 1026 if (CGF.SanOpts->Bounds) 1027 CGF.EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, /*Accessed*/true); 1028 1029 bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType(); 1030 Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vecidxcast"); 1031 return Builder.CreateExtractElement(Base, Idx, "vecext"); 1032} 1033 1034static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, 1035 unsigned Off, llvm::Type *I32Ty) { 1036 int MV = SVI->getMaskValue(Idx); 1037 if (MV == -1) 1038 return llvm::UndefValue::get(I32Ty); 1039 return llvm::ConstantInt::get(I32Ty, Off+MV); 1040} 1041 1042Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) { 1043 bool Ignore = TestAndClearIgnoreResultAssign(); 1044 (void)Ignore; 1045 assert (Ignore == false && "init list ignored"); 1046 unsigned NumInitElements = E->getNumInits(); 1047 1048 if (E->hadArrayRangeDesignator()) 1049 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 1050 1051 llvm::VectorType *VType = 1052 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 1053 1054 if (!VType) { 1055 if (NumInitElements == 0) { 1056 // C++11 value-initialization for the scalar. 1057 return EmitNullValue(E->getType()); 1058 } 1059 // We have a scalar in braces. Just use the first element. 1060 return Visit(E->getInit(0)); 1061 } 1062 1063 unsigned ResElts = VType->getNumElements(); 1064 1065 // Loop over initializers collecting the Value for each, and remembering 1066 // whether the source was swizzle (ExtVectorElementExpr). This will allow 1067 // us to fold the shuffle for the swizzle into the shuffle for the vector 1068 // initializer, since LLVM optimizers generally do not want to touch 1069 // shuffles. 1070 unsigned CurIdx = 0; 1071 bool VIsUndefShuffle = false; 1072 llvm::Value *V = llvm::UndefValue::get(VType); 1073 for (unsigned i = 0; i != NumInitElements; ++i) { 1074 Expr *IE = E->getInit(i); 1075 Value *Init = Visit(IE); 1076 SmallVector<llvm::Constant*, 16> Args; 1077 1078 llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType()); 1079 1080 // Handle scalar elements. If the scalar initializer is actually one 1081 // element of a different vector of the same width, use shuffle instead of 1082 // extract+insert. 1083 if (!VVT) { 1084 if (isa<ExtVectorElementExpr>(IE)) { 1085 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init); 1086 1087 if (EI->getVectorOperandType()->getNumElements() == ResElts) { 1088 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand()); 1089 Value *LHS = 0, *RHS = 0; 1090 if (CurIdx == 0) { 1091 // insert into undef -> shuffle (src, undef) 1092 Args.push_back(C); 1093 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 1094 1095 LHS = EI->getVectorOperand(); 1096 RHS = V; 1097 VIsUndefShuffle = true; 1098 } else if (VIsUndefShuffle) { 1099 // insert into undefshuffle && size match -> shuffle (v, src) 1100 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V); 1101 for (unsigned j = 0; j != CurIdx; ++j) 1102 Args.push_back(getMaskElt(SVV, j, 0, CGF.Int32Ty)); 1103 Args.push_back(Builder.getInt32(ResElts + C->getZExtValue())); 1104 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 1105 1106 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 1107 RHS = EI->getVectorOperand(); 1108 VIsUndefShuffle = false; 1109 } 1110 if (!Args.empty()) { 1111 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 1112 V = Builder.CreateShuffleVector(LHS, RHS, Mask); 1113 ++CurIdx; 1114 continue; 1115 } 1116 } 1117 } 1118 V = Builder.CreateInsertElement(V, Init, Builder.getInt32(CurIdx), 1119 "vecinit"); 1120 VIsUndefShuffle = false; 1121 ++CurIdx; 1122 continue; 1123 } 1124 1125 unsigned InitElts = VVT->getNumElements(); 1126 1127 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's 1128 // input is the same width as the vector being constructed, generate an 1129 // optimized shuffle of the swizzle input into the result. 1130 unsigned Offset = (CurIdx == 0) ? 0 : ResElts; 1131 if (isa<ExtVectorElementExpr>(IE)) { 1132 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init); 1133 Value *SVOp = SVI->getOperand(0); 1134 llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType()); 1135 1136 if (OpTy->getNumElements() == ResElts) { 1137 for (unsigned j = 0; j != CurIdx; ++j) { 1138 // If the current vector initializer is a shuffle with undef, merge 1139 // this shuffle directly into it. 1140 if (VIsUndefShuffle) { 1141 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0, 1142 CGF.Int32Ty)); 1143 } else { 1144 Args.push_back(Builder.getInt32(j)); 1145 } 1146 } 1147 for (unsigned j = 0, je = InitElts; j != je; ++j) 1148 Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty)); 1149 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 1150 1151 if (VIsUndefShuffle) 1152 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 1153 1154 Init = SVOp; 1155 } 1156 } 1157 1158 // Extend init to result vector length, and then shuffle its contribution 1159 // to the vector initializer into V. 1160 if (Args.empty()) { 1161 for (unsigned j = 0; j != InitElts; ++j) 1162 Args.push_back(Builder.getInt32(j)); 1163 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 1164 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 1165 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), 1166 Mask, "vext"); 1167 1168 Args.clear(); 1169 for (unsigned j = 0; j != CurIdx; ++j) 1170 Args.push_back(Builder.getInt32(j)); 1171 for (unsigned j = 0; j != InitElts; ++j) 1172 Args.push_back(Builder.getInt32(j+Offset)); 1173 Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty)); 1174 } 1175 1176 // If V is undef, make sure it ends up on the RHS of the shuffle to aid 1177 // merging subsequent shuffles into this one. 1178 if (CurIdx == 0) 1179 std::swap(V, Init); 1180 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 1181 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); 1182 VIsUndefShuffle = isa<llvm::UndefValue>(Init); 1183 CurIdx += InitElts; 1184 } 1185 1186 // FIXME: evaluate codegen vs. shuffling against constant null vector. 1187 // Emit remaining default initializers. 1188 llvm::Type *EltTy = VType->getElementType(); 1189 1190 // Emit remaining default initializers 1191 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { 1192 Value *Idx = Builder.getInt32(CurIdx); 1193 llvm::Value *Init = llvm::Constant::getNullValue(EltTy); 1194 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 1195 } 1196 return V; 1197} 1198 1199static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { 1200 const Expr *E = CE->getSubExpr(); 1201 1202 if (CE->getCastKind() == CK_UncheckedDerivedToBase) 1203 return false; 1204 1205 if (isa<CXXThisExpr>(E)) { 1206 // We always assume that 'this' is never null. 1207 return false; 1208 } 1209 1210 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { 1211 // And that glvalue casts are never null. 1212 if (ICE->getValueKind() != VK_RValue) 1213 return false; 1214 } 1215 1216 return true; 1217} 1218 1219// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 1220// have to handle a more broad range of conversions than explicit casts, as they 1221// handle things like function to ptr-to-function decay etc. 1222Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) { 1223 Expr *E = CE->getSubExpr(); 1224 QualType DestTy = CE->getType(); 1225 CastKind Kind = CE->getCastKind(); 1226 1227 if (!DestTy->isVoidType()) 1228 TestAndClearIgnoreResultAssign(); 1229 1230 // Since almost all cast kinds apply to scalars, this switch doesn't have 1231 // a default case, so the compiler will warn on a missing case. The cases 1232 // are in the same order as in the CastKind enum. 1233 switch (Kind) { 1234 case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!"); 1235 case CK_BuiltinFnToFnPtr: 1236 llvm_unreachable("builtin functions are handled elsewhere"); 1237 1238 case CK_LValueBitCast: 1239 case CK_ObjCObjectLValueCast: { 1240 Value *V = EmitLValue(E).getAddress(); 1241 V = Builder.CreateBitCast(V, 1242 ConvertType(CGF.getContext().getPointerType(DestTy))); 1243 return EmitLoadOfLValue(CGF.MakeNaturalAlignAddrLValue(V, DestTy)); 1244 } 1245 1246 case CK_CPointerToObjCPointerCast: 1247 case CK_BlockPointerToObjCPointerCast: 1248 case CK_AnyPointerToBlockPointerCast: 1249 case CK_BitCast: { 1250 Value *Src = Visit(const_cast<Expr*>(E)); 1251 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 1252 } 1253 case CK_AtomicToNonAtomic: 1254 case CK_NonAtomicToAtomic: 1255 case CK_NoOp: 1256 case CK_UserDefinedConversion: 1257 return Visit(const_cast<Expr*>(E)); 1258 1259 case CK_BaseToDerived: { 1260 const CXXRecordDecl *DerivedClassDecl = DestTy->getPointeeCXXRecordDecl(); 1261 assert(DerivedClassDecl && "BaseToDerived arg isn't a C++ object pointer!"); 1262 1263 llvm::Value *V = Visit(E); 1264 1265 // C++11 [expr.static.cast]p11: Behavior is undefined if a downcast is 1266 // performed and the object is not of the derived type. 1267 if (CGF.SanitizePerformTypeCheck) 1268 CGF.EmitTypeCheck(CodeGenFunction::TCK_DowncastPointer, CE->getExprLoc(), 1269 V, DestTy->getPointeeType()); 1270 1271 return CGF.GetAddressOfDerivedClass(V, DerivedClassDecl, 1272 CE->path_begin(), CE->path_end(), 1273 ShouldNullCheckClassCastValue(CE)); 1274 } 1275 case CK_UncheckedDerivedToBase: 1276 case CK_DerivedToBase: { 1277 const CXXRecordDecl *DerivedClassDecl = 1278 E->getType()->getPointeeCXXRecordDecl(); 1279 assert(DerivedClassDecl && "DerivedToBase arg isn't a C++ object pointer!"); 1280 1281 return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl, 1282 CE->path_begin(), CE->path_end(), 1283 ShouldNullCheckClassCastValue(CE)); 1284 } 1285 case CK_Dynamic: { 1286 Value *V = Visit(const_cast<Expr*>(E)); 1287 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 1288 return CGF.EmitDynamicCast(V, DCE); 1289 } 1290 1291 case CK_ArrayToPointerDecay: { 1292 assert(E->getType()->isArrayType() && 1293 "Array to pointer decay must have array source type!"); 1294 1295 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 1296 1297 // Note that VLA pointers are always decayed, so we don't need to do 1298 // anything here. 1299 if (!E->getType()->isVariableArrayType()) { 1300 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 1301 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 1302 ->getElementType()) && 1303 "Expected pointer to array"); 1304 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 1305 } 1306 1307 // Make sure the array decay ends up being the right type. This matters if 1308 // the array type was of an incomplete type. 1309 return CGF.Builder.CreateBitCast(V, ConvertType(CE->getType())); 1310 } 1311 case CK_FunctionToPointerDecay: 1312 return EmitLValue(E).getAddress(); 1313 1314 case CK_NullToPointer: 1315 if (MustVisitNullValue(E)) 1316 (void) Visit(E); 1317 1318 return llvm::ConstantPointerNull::get( 1319 cast<llvm::PointerType>(ConvertType(DestTy))); 1320 1321 case CK_NullToMemberPointer: { 1322 if (MustVisitNullValue(E)) 1323 (void) Visit(E); 1324 1325 const MemberPointerType *MPT = CE->getType()->getAs<MemberPointerType>(); 1326 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 1327 } 1328 1329 case CK_ReinterpretMemberPointer: 1330 case CK_BaseToDerivedMemberPointer: 1331 case CK_DerivedToBaseMemberPointer: { 1332 Value *Src = Visit(E); 1333 1334 // Note that the AST doesn't distinguish between checked and 1335 // unchecked member pointer conversions, so we always have to 1336 // implement checked conversions here. This is inefficient when 1337 // actual control flow may be required in order to perform the 1338 // check, which it is for data member pointers (but not member 1339 // function pointers on Itanium and ARM). 1340 return CGF.CGM.getCXXABI().EmitMemberPointerConversion(CGF, CE, Src); 1341 } 1342 1343 case CK_ARCProduceObject: 1344 return CGF.EmitARCRetainScalarExpr(E); 1345 case CK_ARCConsumeObject: 1346 return CGF.EmitObjCConsumeObject(E->getType(), Visit(E)); 1347 case CK_ARCReclaimReturnedObject: { 1348 llvm::Value *value = Visit(E); 1349 value = CGF.EmitARCRetainAutoreleasedReturnValue(value); 1350 return CGF.EmitObjCConsumeObject(E->getType(), value); 1351 } 1352 case CK_ARCExtendBlockObject: 1353 return CGF.EmitARCExtendBlockObject(E); 1354 1355 case CK_CopyAndAutoreleaseBlockObject: 1356 return CGF.EmitBlockCopyAndAutorelease(Visit(E), E->getType()); 1357 1358 case CK_FloatingRealToComplex: 1359 case CK_FloatingComplexCast: 1360 case CK_IntegralRealToComplex: 1361 case CK_IntegralComplexCast: 1362 case CK_IntegralComplexToFloatingComplex: 1363 case CK_FloatingComplexToIntegralComplex: 1364 case CK_ConstructorConversion: 1365 case CK_ToUnion: 1366 llvm_unreachable("scalar cast to non-scalar value"); 1367 1368 case CK_LValueToRValue: 1369 assert(CGF.getContext().hasSameUnqualifiedType(E->getType(), DestTy)); 1370 assert(E->isGLValue() && "lvalue-to-rvalue applied to r-value!"); 1371 return Visit(const_cast<Expr*>(E)); 1372 1373 case CK_IntegralToPointer: { 1374 Value *Src = Visit(const_cast<Expr*>(E)); 1375 1376 // First, convert to the correct width so that we control the kind of 1377 // extension. 1378 llvm::Type *MiddleTy = CGF.IntPtrTy; 1379 bool InputSigned = E->getType()->isSignedIntegerOrEnumerationType(); 1380 llvm::Value* IntResult = 1381 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 1382 1383 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 1384 } 1385 case CK_PointerToIntegral: 1386 assert(!DestTy->isBooleanType() && "bool should use PointerToBool"); 1387 return Builder.CreatePtrToInt(Visit(E), ConvertType(DestTy)); 1388 1389 case CK_ToVoid: { 1390 CGF.EmitIgnoredExpr(E); 1391 return 0; 1392 } 1393 case CK_VectorSplat: { 1394 llvm::Type *DstTy = ConvertType(DestTy); 1395 Value *Elt = Visit(const_cast<Expr*>(E)); 1396 Elt = EmitScalarConversion(Elt, E->getType(), 1397 DestTy->getAs<VectorType>()->getElementType()); 1398 1399 // Splat the element across to all elements 1400 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 1401 return Builder.CreateVectorSplat(NumElements, Elt, "splat");; 1402 } 1403 1404 case CK_IntegralCast: 1405 case CK_IntegralToFloating: 1406 case CK_FloatingToIntegral: 1407 case CK_FloatingCast: 1408 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 1409 case CK_IntegralToBoolean: 1410 return EmitIntToBoolConversion(Visit(E)); 1411 case CK_PointerToBoolean: 1412 return EmitPointerToBoolConversion(Visit(E)); 1413 case CK_FloatingToBoolean: 1414 return EmitFloatToBoolConversion(Visit(E)); 1415 case CK_MemberPointerToBoolean: { 1416 llvm::Value *MemPtr = Visit(E); 1417 const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>(); 1418 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT); 1419 } 1420 1421 case CK_FloatingComplexToReal: 1422 case CK_IntegralComplexToReal: 1423 return CGF.EmitComplexExpr(E, false, true).first; 1424 1425 case CK_FloatingComplexToBoolean: 1426 case CK_IntegralComplexToBoolean: { 1427 CodeGenFunction::ComplexPairTy V = CGF.EmitComplexExpr(E); 1428 1429 // TODO: kill this function off, inline appropriate case here 1430 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 1431 } 1432 1433 case CK_ZeroToOCLEvent: { 1434 assert(DestTy->isEventT() && "CK_ZeroToOCLEvent cast on non event type"); 1435 return llvm::Constant::getNullValue(ConvertType(DestTy)); 1436 } 1437 1438 } 1439 1440 llvm_unreachable("unknown scalar cast"); 1441} 1442 1443Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 1444 CodeGenFunction::StmtExprEvaluation eval(CGF); 1445 return CGF.EmitCompoundStmt(*E->getSubStmt(), !E->getType()->isVoidType()) 1446 .getScalarVal(); 1447} 1448 1449//===----------------------------------------------------------------------===// 1450// Unary Operators 1451//===----------------------------------------------------------------------===// 1452 1453llvm::Value *ScalarExprEmitter:: 1454EmitAddConsiderOverflowBehavior(const UnaryOperator *E, 1455 llvm::Value *InVal, 1456 llvm::Value *NextVal, bool IsInc) { 1457 switch (CGF.getLangOpts().getSignedOverflowBehavior()) { 1458 case LangOptions::SOB_Defined: 1459 return Builder.CreateAdd(InVal, NextVal, IsInc ? "inc" : "dec"); 1460 case LangOptions::SOB_Undefined: 1461 if (!CGF.SanOpts->SignedIntegerOverflow) 1462 return Builder.CreateNSWAdd(InVal, NextVal, IsInc ? "inc" : "dec"); 1463 // Fall through. 1464 case LangOptions::SOB_Trapping: 1465 BinOpInfo BinOp; 1466 BinOp.LHS = InVal; 1467 BinOp.RHS = NextVal; 1468 BinOp.Ty = E->getType(); 1469 BinOp.Opcode = BO_Add; 1470 BinOp.FPContractable = false; 1471 BinOp.E = E; 1472 return EmitOverflowCheckedBinOp(BinOp); 1473 } 1474 llvm_unreachable("Unknown SignedOverflowBehaviorTy"); 1475} 1476 1477llvm::Value * 1478ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 1479 bool isInc, bool isPre) { 1480 1481 QualType type = E->getSubExpr()->getType(); 1482 llvm::PHINode *atomicPHI = 0; 1483 llvm::Value *value; 1484 llvm::Value *input; 1485 1486 int amount = (isInc ? 1 : -1); 1487 1488 if (const AtomicType *atomicTy = type->getAs<AtomicType>()) { 1489 type = atomicTy->getValueType(); 1490 if (isInc && type->isBooleanType()) { 1491 llvm::Value *True = CGF.EmitToMemory(Builder.getTrue(), type); 1492 if (isPre) { 1493 Builder.Insert(new llvm::StoreInst(True, 1494 LV.getAddress(), LV.isVolatileQualified(), 1495 LV.getAlignment().getQuantity(), 1496 llvm::SequentiallyConsistent)); 1497 return Builder.getTrue(); 1498 } 1499 // For atomic bool increment, we just store true and return it for 1500 // preincrement, do an atomic swap with true for postincrement 1501 return Builder.CreateAtomicRMW(llvm::AtomicRMWInst::Xchg, 1502 LV.getAddress(), True, llvm::SequentiallyConsistent); 1503 } 1504 // Special case for atomic increment / decrement on integers, emit 1505 // atomicrmw instructions. We skip this if we want to be doing overflow 1506 // checking, and fall into the slow path with the atomic cmpxchg loop. 1507 if (!type->isBooleanType() && type->isIntegerType() && 1508 !(type->isUnsignedIntegerType() && 1509 CGF.SanOpts->UnsignedIntegerOverflow) && 1510 CGF.getLangOpts().getSignedOverflowBehavior() != 1511 LangOptions::SOB_Trapping) { 1512 llvm::AtomicRMWInst::BinOp aop = isInc ? llvm::AtomicRMWInst::Add : 1513 llvm::AtomicRMWInst::Sub; 1514 llvm::Instruction::BinaryOps op = isInc ? llvm::Instruction::Add : 1515 llvm::Instruction::Sub; 1516 llvm::Value *amt = CGF.EmitToMemory( 1517 llvm::ConstantInt::get(ConvertType(type), 1, true), type); 1518 llvm::Value *old = Builder.CreateAtomicRMW(aop, 1519 LV.getAddress(), amt, llvm::SequentiallyConsistent); 1520 return isPre ? Builder.CreateBinOp(op, old, amt) : old; 1521 } 1522 value = EmitLoadOfLValue(LV); 1523 input = value; 1524 // For every other atomic operation, we need to emit a load-op-cmpxchg loop 1525 llvm::BasicBlock *startBB = Builder.GetInsertBlock(); 1526 llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn); 1527 value = CGF.EmitToMemory(value, type); 1528 Builder.CreateBr(opBB); 1529 Builder.SetInsertPoint(opBB); 1530 atomicPHI = Builder.CreatePHI(value->getType(), 2); 1531 atomicPHI->addIncoming(value, startBB); 1532 value = atomicPHI; 1533 } else { 1534 value = EmitLoadOfLValue(LV); 1535 input = value; 1536 } 1537 1538 // Special case of integer increment that we have to check first: bool++. 1539 // Due to promotion rules, we get: 1540 // bool++ -> bool = bool + 1 1541 // -> bool = (int)bool + 1 1542 // -> bool = ((int)bool + 1 != 0) 1543 // An interesting aspect of this is that increment is always true. 1544 // Decrement does not have this property. 1545 if (isInc && type->isBooleanType()) { 1546 value = Builder.getTrue(); 1547 1548 // Most common case by far: integer increment. 1549 } else if (type->isIntegerType()) { 1550 1551 llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount, true); 1552 1553 // Note that signed integer inc/dec with width less than int can't 1554 // overflow because of promotion rules; we're just eliding a few steps here. 1555 if (value->getType()->getPrimitiveSizeInBits() >= 1556 CGF.IntTy->getBitWidth() && 1557 type->isSignedIntegerOrEnumerationType()) { 1558 value = EmitAddConsiderOverflowBehavior(E, value, amt, isInc); 1559 } else if (value->getType()->getPrimitiveSizeInBits() >= 1560 CGF.IntTy->getBitWidth() && type->isUnsignedIntegerType() && 1561 CGF.SanOpts->UnsignedIntegerOverflow) { 1562 BinOpInfo BinOp; 1563 BinOp.LHS = value; 1564 BinOp.RHS = llvm::ConstantInt::get(value->getType(), 1, false); 1565 BinOp.Ty = E->getType(); 1566 BinOp.Opcode = isInc ? BO_Add : BO_Sub; 1567 BinOp.FPContractable = false; 1568 BinOp.E = E; 1569 value = EmitOverflowCheckedBinOp(BinOp); 1570 } else 1571 value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec"); 1572 1573 // Next most common: pointer increment. 1574 } else if (const PointerType *ptr = type->getAs<PointerType>()) { 1575 QualType type = ptr->getPointeeType(); 1576 1577 // VLA types don't have constant size. 1578 if (const VariableArrayType *vla 1579 = CGF.getContext().getAsVariableArrayType(type)) { 1580 llvm::Value *numElts = CGF.getVLASize(vla).first; 1581 if (!isInc) numElts = Builder.CreateNSWNeg(numElts, "vla.negsize"); 1582 if (CGF.getLangOpts().isSignedOverflowDefined()) 1583 value = Builder.CreateGEP(value, numElts, "vla.inc"); 1584 else 1585 value = Builder.CreateInBoundsGEP(value, numElts, "vla.inc"); 1586 1587 // Arithmetic on function pointers (!) is just +-1. 1588 } else if (type->isFunctionType()) { 1589 llvm::Value *amt = Builder.getInt32(amount); 1590 1591 value = CGF.EmitCastToVoidPtr(value); 1592 if (CGF.getLangOpts().isSignedOverflowDefined()) 1593 value = Builder.CreateGEP(value, amt, "incdec.funcptr"); 1594 else 1595 value = Builder.CreateInBoundsGEP(value, amt, "incdec.funcptr"); 1596 value = Builder.CreateBitCast(value, input->getType()); 1597 1598 // For everything else, we can just do a simple increment. 1599 } else { 1600 llvm::Value *amt = Builder.getInt32(amount); 1601 if (CGF.getLangOpts().isSignedOverflowDefined()) 1602 value = Builder.CreateGEP(value, amt, "incdec.ptr"); 1603 else 1604 value = Builder.CreateInBoundsGEP(value, amt, "incdec.ptr"); 1605 } 1606 1607 // Vector increment/decrement. 1608 } else if (type->isVectorType()) { 1609 if (type->hasIntegerRepresentation()) { 1610 llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount); 1611 1612 value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec"); 1613 } else { 1614 value = Builder.CreateFAdd( 1615 value, 1616 llvm::ConstantFP::get(value->getType(), amount), 1617 isInc ? "inc" : "dec"); 1618 } 1619 1620 // Floating point. 1621 } else if (type->isRealFloatingType()) { 1622 // Add the inc/dec to the real part. 1623 llvm::Value *amt; 1624 1625 if (type->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) { 1626 // Another special case: half FP increment should be done via float 1627 value = 1628 Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_from_fp16), 1629 input); 1630 } 1631 1632 if (value->getType()->isFloatTy()) 1633 amt = llvm::ConstantFP::get(VMContext, 1634 llvm::APFloat(static_cast<float>(amount))); 1635 else if (value->getType()->isDoubleTy()) 1636 amt = llvm::ConstantFP::get(VMContext, 1637 llvm::APFloat(static_cast<double>(amount))); 1638 else { 1639 llvm::APFloat F(static_cast<float>(amount)); 1640 bool ignored; 1641 F.convert(CGF.getTarget().getLongDoubleFormat(), 1642 llvm::APFloat::rmTowardZero, &ignored); 1643 amt = llvm::ConstantFP::get(VMContext, F); 1644 } 1645 value = Builder.CreateFAdd(value, amt, isInc ? "inc" : "dec"); 1646 1647 if (type->isHalfType() && !CGF.getContext().getLangOpts().NativeHalfType) 1648 value = 1649 Builder.CreateCall(CGF.CGM.getIntrinsic(llvm::Intrinsic::convert_to_fp16), 1650 value); 1651 1652 // Objective-C pointer types. 1653 } else { 1654 const ObjCObjectPointerType *OPT = type->castAs<ObjCObjectPointerType>(); 1655 value = CGF.EmitCastToVoidPtr(value); 1656 1657 CharUnits size = CGF.getContext().getTypeSizeInChars(OPT->getObjectType()); 1658 if (!isInc) size = -size; 1659 llvm::Value *sizeValue = 1660 llvm::ConstantInt::get(CGF.SizeTy, size.getQuantity()); 1661 1662 if (CGF.getLangOpts().isSignedOverflowDefined()) 1663 value = Builder.CreateGEP(value, sizeValue, "incdec.objptr"); 1664 else 1665 value = Builder.CreateInBoundsGEP(value, sizeValue, "incdec.objptr"); 1666 value = Builder.CreateBitCast(value, input->getType()); 1667 } 1668 1669 if (atomicPHI) { 1670 llvm::BasicBlock *opBB = Builder.GetInsertBlock(); 1671 llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn); 1672 llvm::Value *old = Builder.CreateAtomicCmpXchg(LV.getAddress(), atomicPHI, 1673 CGF.EmitToMemory(value, type), llvm::SequentiallyConsistent); 1674 atomicPHI->addIncoming(old, opBB); 1675 llvm::Value *success = Builder.CreateICmpEQ(old, atomicPHI); 1676 Builder.CreateCondBr(success, contBB, opBB); 1677 Builder.SetInsertPoint(contBB); 1678 return isPre ? value : input; 1679 } 1680 1681 // Store the updated result through the lvalue. 1682 if (LV.isBitField()) 1683 CGF.EmitStoreThroughBitfieldLValue(RValue::get(value), LV, &value); 1684 else 1685 CGF.EmitStoreThroughLValue(RValue::get(value), LV); 1686 1687 // If this is a postinc, return the value read from memory, otherwise use the 1688 // updated value. 1689 return isPre ? value : input; 1690} 1691 1692 1693 1694Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1695 TestAndClearIgnoreResultAssign(); 1696 // Emit unary minus with EmitSub so we handle overflow cases etc. 1697 BinOpInfo BinOp; 1698 BinOp.RHS = Visit(E->getSubExpr()); 1699 1700 if (BinOp.RHS->getType()->isFPOrFPVectorTy()) 1701 BinOp.LHS = llvm::ConstantFP::getZeroValueForNegation(BinOp.RHS->getType()); 1702 else 1703 BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType()); 1704 BinOp.Ty = E->getType(); 1705 BinOp.Opcode = BO_Sub; 1706 BinOp.FPContractable = false; 1707 BinOp.E = E; 1708 return EmitSub(BinOp); 1709} 1710 1711Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1712 TestAndClearIgnoreResultAssign(); 1713 Value *Op = Visit(E->getSubExpr()); 1714 return Builder.CreateNot(Op, "neg"); 1715} 1716 1717Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1718 // Perform vector logical not on comparison with zero vector. 1719 if (E->getType()->isExtVectorType()) { 1720 Value *Oper = Visit(E->getSubExpr()); 1721 Value *Zero = llvm::Constant::getNullValue(Oper->getType()); 1722 Value *Result; 1723 if (Oper->getType()->isFPOrFPVectorTy()) 1724 Result = Builder.CreateFCmp(llvm::CmpInst::FCMP_OEQ, Oper, Zero, "cmp"); 1725 else 1726 Result = Builder.CreateICmp(llvm::CmpInst::ICMP_EQ, Oper, Zero, "cmp"); 1727 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 1728 } 1729 1730 // Compare operand to zero. 1731 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1732 1733 // Invert value. 1734 // TODO: Could dynamically modify easy computations here. For example, if 1735 // the operand is an icmp ne, turn into icmp eq. 1736 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1737 1738 // ZExt result to the expr type. 1739 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1740} 1741 1742Value *ScalarExprEmitter::VisitOffsetOfExpr(OffsetOfExpr *E) { 1743 // Try folding the offsetof to a constant. 1744 llvm::APSInt Value; 1745 if (E->EvaluateAsInt(Value, CGF.getContext())) 1746 return Builder.getInt(Value); 1747 1748 // Loop over the components of the offsetof to compute the value. 1749 unsigned n = E->getNumComponents(); 1750 llvm::Type* ResultType = ConvertType(E->getType()); 1751 llvm::Value* Result = llvm::Constant::getNullValue(ResultType); 1752 QualType CurrentType = E->getTypeSourceInfo()->getType(); 1753 for (unsigned i = 0; i != n; ++i) { 1754 OffsetOfExpr::OffsetOfNode ON = E->getComponent(i); 1755 llvm::Value *Offset = 0; 1756 switch (ON.getKind()) { 1757 case OffsetOfExpr::OffsetOfNode::Array: { 1758 // Compute the index 1759 Expr *IdxExpr = E->getIndexExpr(ON.getArrayExprIndex()); 1760 llvm::Value* Idx = CGF.EmitScalarExpr(IdxExpr); 1761 bool IdxSigned = IdxExpr->getType()->isSignedIntegerOrEnumerationType(); 1762 Idx = Builder.CreateIntCast(Idx, ResultType, IdxSigned, "conv"); 1763 1764 // Save the element type 1765 CurrentType = 1766 CGF.getContext().getAsArrayType(CurrentType)->getElementType(); 1767 1768 // Compute the element size 1769 llvm::Value* ElemSize = llvm::ConstantInt::get(ResultType, 1770 CGF.getContext().getTypeSizeInChars(CurrentType).getQuantity()); 1771 1772 // Multiply out to compute the result 1773 Offset = Builder.CreateMul(Idx, ElemSize); 1774 break; 1775 } 1776 1777 case OffsetOfExpr::OffsetOfNode::Field: { 1778 FieldDecl *MemberDecl = ON.getField(); 1779 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1780 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1781 1782 // Compute the index of the field in its parent. 1783 unsigned i = 0; 1784 // FIXME: It would be nice if we didn't have to loop here! 1785 for (RecordDecl::field_iterator Field = RD->field_begin(), 1786 FieldEnd = RD->field_end(); 1787 Field != FieldEnd; ++Field, ++i) { 1788 if (*Field == MemberDecl) 1789 break; 1790 } 1791 assert(i < RL.getFieldCount() && "offsetof field in wrong type"); 1792 1793 // Compute the offset to the field 1794 int64_t OffsetInt = RL.getFieldOffset(i) / 1795 CGF.getContext().getCharWidth(); 1796 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1797 1798 // Save the element type. 1799 CurrentType = MemberDecl->getType(); 1800 break; 1801 } 1802 1803 case OffsetOfExpr::OffsetOfNode::Identifier: 1804 llvm_unreachable("dependent __builtin_offsetof"); 1805 1806 case OffsetOfExpr::OffsetOfNode::Base: { 1807 if (ON.getBase()->isVirtual()) { 1808 CGF.ErrorUnsupported(E, "virtual base in offsetof"); 1809 continue; 1810 } 1811 1812 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1813 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1814 1815 // Save the element type. 1816 CurrentType = ON.getBase()->getType(); 1817 1818 // Compute the offset to the base. 1819 const RecordType *BaseRT = CurrentType->getAs<RecordType>(); 1820 CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl()); 1821 CharUnits OffsetInt = RL.getBaseClassOffset(BaseRD); 1822 Offset = llvm::ConstantInt::get(ResultType, OffsetInt.getQuantity()); 1823 break; 1824 } 1825 } 1826 Result = Builder.CreateAdd(Result, Offset); 1827 } 1828 return Result; 1829} 1830 1831/// VisitUnaryExprOrTypeTraitExpr - Return the size or alignment of the type of 1832/// argument of the sizeof expression as an integer. 1833Value * 1834ScalarExprEmitter::VisitUnaryExprOrTypeTraitExpr( 1835 const UnaryExprOrTypeTraitExpr *E) { 1836 QualType TypeToSize = E->getTypeOfArgument(); 1837 if (E->getKind() == UETT_SizeOf) { 1838 if (const VariableArrayType *VAT = 1839 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1840 if (E->isArgumentType()) { 1841 // sizeof(type) - make sure to emit the VLA size. 1842 CGF.EmitVariablyModifiedType(TypeToSize); 1843 } else { 1844 // C99 6.5.3.4p2: If the argument is an expression of type 1845 // VLA, it is evaluated. 1846 CGF.EmitIgnoredExpr(E->getArgumentExpr()); 1847 } 1848 1849 QualType eltType; 1850 llvm::Value *numElts; 1851 llvm::tie(numElts, eltType) = CGF.getVLASize(VAT); 1852 1853 llvm::Value *size = numElts; 1854 1855 // Scale the number of non-VLA elements by the non-VLA element size. 1856 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType); 1857 if (!eltSize.isOne()) 1858 size = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), numElts); 1859 1860 return size; 1861 } 1862 } 1863 1864 // If this isn't sizeof(vla), the result must be constant; use the constant 1865 // folding logic so we don't have to duplicate it here. 1866 return Builder.getInt(E->EvaluateKnownConstInt(CGF.getContext())); 1867} 1868 1869Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1870 Expr *Op = E->getSubExpr(); 1871 if (Op->getType()->isAnyComplexType()) { 1872 // If it's an l-value, load through the appropriate subobject l-value. 1873 // Note that we have to ask E because Op might be an l-value that 1874 // this won't work for, e.g. an Obj-C property. 1875 if (E->isGLValue()) 1876 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E)).getScalarVal(); 1877 1878 // Otherwise, calculate and project. 1879 return CGF.EmitComplexExpr(Op, false, true).first; 1880 } 1881 1882 return Visit(Op); 1883} 1884 1885Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1886 Expr *Op = E->getSubExpr(); 1887 if (Op->getType()->isAnyComplexType()) { 1888 // If it's an l-value, load through the appropriate subobject l-value. 1889 // Note that we have to ask E because Op might be an l-value that 1890 // this won't work for, e.g. an Obj-C property. 1891 if (Op->isGLValue()) 1892 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E)).getScalarVal(); 1893 1894 // Otherwise, calculate and project. 1895 return CGF.EmitComplexExpr(Op, true, false).second; 1896 } 1897 1898 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1899 // effects are evaluated, but not the actual value. 1900 if (Op->isGLValue()) 1901 CGF.EmitLValue(Op); 1902 else 1903 CGF.EmitScalarExpr(Op, true); 1904 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1905} 1906 1907//===----------------------------------------------------------------------===// 1908// Binary Operators 1909//===----------------------------------------------------------------------===// 1910 1911BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1912 TestAndClearIgnoreResultAssign(); 1913 BinOpInfo Result; 1914 Result.LHS = Visit(E->getLHS()); 1915 Result.RHS = Visit(E->getRHS()); 1916 Result.Ty = E->getType(); 1917 Result.Opcode = E->getOpcode(); 1918 Result.FPContractable = E->isFPContractable(); 1919 Result.E = E; 1920 return Result; 1921} 1922 1923LValue ScalarExprEmitter::EmitCompoundAssignLValue( 1924 const CompoundAssignOperator *E, 1925 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &), 1926 Value *&Result) { 1927 QualType LHSTy = E->getLHS()->getType(); 1928 BinOpInfo OpInfo; 1929 1930 if (E->getComputationResultType()->isAnyComplexType()) { 1931 // This needs to go through the complex expression emitter, but it's a tad 1932 // complicated to do that... I'm leaving it out for now. (Note that we do 1933 // actually need the imaginary part of the RHS for multiplication and 1934 // division.) 1935 CGF.ErrorUnsupported(E, "complex compound assignment"); 1936 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType())); 1937 return LValue(); 1938 } 1939 1940 // Emit the RHS first. __block variables need to have the rhs evaluated 1941 // first, plus this should improve codegen a little. 1942 OpInfo.RHS = Visit(E->getRHS()); 1943 OpInfo.Ty = E->getComputationResultType(); 1944 OpInfo.Opcode = E->getOpcode(); 1945 OpInfo.FPContractable = false; 1946 OpInfo.E = E; 1947 // Load/convert the LHS. 1948 LValue LHSLV = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store); 1949 1950 llvm::PHINode *atomicPHI = 0; 1951 if (const AtomicType *atomicTy = LHSTy->getAs<AtomicType>()) { 1952 QualType type = atomicTy->getValueType(); 1953 if (!type->isBooleanType() && type->isIntegerType() && 1954 !(type->isUnsignedIntegerType() && 1955 CGF.SanOpts->UnsignedIntegerOverflow) && 1956 CGF.getLangOpts().getSignedOverflowBehavior() != 1957 LangOptions::SOB_Trapping) { 1958 llvm::AtomicRMWInst::BinOp aop = llvm::AtomicRMWInst::BAD_BINOP; 1959 switch (OpInfo.Opcode) { 1960 // We don't have atomicrmw operands for *, %, /, <<, >> 1961 case BO_MulAssign: case BO_DivAssign: 1962 case BO_RemAssign: 1963 case BO_ShlAssign: 1964 case BO_ShrAssign: 1965 break; 1966 case BO_AddAssign: 1967 aop = llvm::AtomicRMWInst::Add; 1968 break; 1969 case BO_SubAssign: 1970 aop = llvm::AtomicRMWInst::Sub; 1971 break; 1972 case BO_AndAssign: 1973 aop = llvm::AtomicRMWInst::And; 1974 break; 1975 case BO_XorAssign: 1976 aop = llvm::AtomicRMWInst::Xor; 1977 break; 1978 case BO_OrAssign: 1979 aop = llvm::AtomicRMWInst::Or; 1980 break; 1981 default: 1982 llvm_unreachable("Invalid compound assignment type"); 1983 } 1984 if (aop != llvm::AtomicRMWInst::BAD_BINOP) { 1985 llvm::Value *amt = CGF.EmitToMemory(EmitScalarConversion(OpInfo.RHS, 1986 E->getRHS()->getType(), LHSTy), LHSTy); 1987 Builder.CreateAtomicRMW(aop, LHSLV.getAddress(), amt, 1988 llvm::SequentiallyConsistent); 1989 return LHSLV; 1990 } 1991 } 1992 // FIXME: For floating point types, we should be saving and restoring the 1993 // floating point environment in the loop. 1994 llvm::BasicBlock *startBB = Builder.GetInsertBlock(); 1995 llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn); 1996 OpInfo.LHS = EmitLoadOfLValue(LHSLV); 1997 OpInfo.LHS = CGF.EmitToMemory(OpInfo.LHS, type); 1998 Builder.CreateBr(opBB); 1999 Builder.SetInsertPoint(opBB); 2000 atomicPHI = Builder.CreatePHI(OpInfo.LHS->getType(), 2); 2001 atomicPHI->addIncoming(OpInfo.LHS, startBB); 2002 OpInfo.LHS = atomicPHI; 2003 } 2004 else 2005 OpInfo.LHS = EmitLoadOfLValue(LHSLV); 2006 2007 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 2008 E->getComputationLHSType()); 2009 2010 // Expand the binary operator. 2011 Result = (this->*Func)(OpInfo); 2012 2013 // Convert the result back to the LHS type. 2014 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 2015 2016 if (atomicPHI) { 2017 llvm::BasicBlock *opBB = Builder.GetInsertBlock(); 2018 llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn); 2019 llvm::Value *old = Builder.CreateAtomicCmpXchg(LHSLV.getAddress(), atomicPHI, 2020 CGF.EmitToMemory(Result, LHSTy), llvm::SequentiallyConsistent); 2021 atomicPHI->addIncoming(old, opBB); 2022 llvm::Value *success = Builder.CreateICmpEQ(old, atomicPHI); 2023 Builder.CreateCondBr(success, contBB, opBB); 2024 Builder.SetInsertPoint(contBB); 2025 return LHSLV; 2026 } 2027 2028 // Store the result value into the LHS lvalue. Bit-fields are handled 2029 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 2030 // 'An assignment expression has the value of the left operand after the 2031 // assignment...'. 2032 if (LHSLV.isBitField()) 2033 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, &Result); 2034 else 2035 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV); 2036 2037 return LHSLV; 2038} 2039 2040Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 2041 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 2042 bool Ignore = TestAndClearIgnoreResultAssign(); 2043 Value *RHS; 2044 LValue LHS = EmitCompoundAssignLValue(E, Func, RHS); 2045 2046 // If the result is clearly ignored, return now. 2047 if (Ignore) 2048 return 0; 2049 2050 // The result of an assignment in C is the assigned r-value. 2051 if (!CGF.getLangOpts().CPlusPlus) 2052 return RHS; 2053 2054 // If the lvalue is non-volatile, return the computed value of the assignment. 2055 if (!LHS.isVolatileQualified()) 2056 return RHS; 2057 2058 // Otherwise, reload the value. 2059 return EmitLoadOfLValue(LHS); 2060} 2061 2062void ScalarExprEmitter::EmitUndefinedBehaviorIntegerDivAndRemCheck( 2063 const BinOpInfo &Ops, llvm::Value *Zero, bool isDiv) { 2064 llvm::Value *Cond = 0; 2065 2066 if (CGF.SanOpts->IntegerDivideByZero) 2067 Cond = Builder.CreateICmpNE(Ops.RHS, Zero); 2068 2069 if (CGF.SanOpts->SignedIntegerOverflow && 2070 Ops.Ty->hasSignedIntegerRepresentation()) { 2071 llvm::IntegerType *Ty = cast<llvm::IntegerType>(Zero->getType()); 2072 2073 llvm::Value *IntMin = 2074 Builder.getInt(llvm::APInt::getSignedMinValue(Ty->getBitWidth())); 2075 llvm::Value *NegOne = llvm::ConstantInt::get(Ty, -1ULL); 2076 2077 llvm::Value *LHSCmp = Builder.CreateICmpNE(Ops.LHS, IntMin); 2078 llvm::Value *RHSCmp = Builder.CreateICmpNE(Ops.RHS, NegOne); 2079 llvm::Value *Overflow = Builder.CreateOr(LHSCmp, RHSCmp, "or"); 2080 Cond = Cond ? Builder.CreateAnd(Cond, Overflow, "and") : Overflow; 2081 } 2082 2083 if (Cond) 2084 EmitBinOpCheck(Cond, Ops); 2085} 2086 2087Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 2088 if ((CGF.SanOpts->IntegerDivideByZero || 2089 CGF.SanOpts->SignedIntegerOverflow) && 2090 Ops.Ty->isIntegerType()) { 2091 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 2092 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, true); 2093 } else if (CGF.SanOpts->FloatDivideByZero && 2094 Ops.Ty->isRealFloatingType()) { 2095 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 2096 EmitBinOpCheck(Builder.CreateFCmpUNE(Ops.RHS, Zero), Ops); 2097 } 2098 2099 if (Ops.LHS->getType()->isFPOrFPVectorTy()) { 2100 llvm::Value *Val = Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 2101 if (CGF.getLangOpts().OpenCL) { 2102 // OpenCL 1.1 7.4: minimum accuracy of single precision / is 2.5ulp 2103 llvm::Type *ValTy = Val->getType(); 2104 if (ValTy->isFloatTy() || 2105 (isa<llvm::VectorType>(ValTy) && 2106 cast<llvm::VectorType>(ValTy)->getElementType()->isFloatTy())) 2107 CGF.SetFPAccuracy(Val, 2.5); 2108 } 2109 return Val; 2110 } 2111 else if (Ops.Ty->hasUnsignedIntegerRepresentation()) 2112 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 2113 else 2114 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 2115} 2116 2117Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 2118 // Rem in C can't be a floating point type: C99 6.5.5p2. 2119 if (CGF.SanOpts->IntegerDivideByZero) { 2120 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 2121 2122 if (Ops.Ty->isIntegerType()) 2123 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, false); 2124 } 2125 2126 if (Ops.Ty->hasUnsignedIntegerRepresentation()) 2127 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 2128 else 2129 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 2130} 2131 2132Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 2133 unsigned IID; 2134 unsigned OpID = 0; 2135 2136 bool isSigned = Ops.Ty->isSignedIntegerOrEnumerationType(); 2137 switch (Ops.Opcode) { 2138 case BO_Add: 2139 case BO_AddAssign: 2140 OpID = 1; 2141 IID = isSigned ? llvm::Intrinsic::sadd_with_overflow : 2142 llvm::Intrinsic::uadd_with_overflow; 2143 break; 2144 case BO_Sub: 2145 case BO_SubAssign: 2146 OpID = 2; 2147 IID = isSigned ? llvm::Intrinsic::ssub_with_overflow : 2148 llvm::Intrinsic::usub_with_overflow; 2149 break; 2150 case BO_Mul: 2151 case BO_MulAssign: 2152 OpID = 3; 2153 IID = isSigned ? llvm::Intrinsic::smul_with_overflow : 2154 llvm::Intrinsic::umul_with_overflow; 2155 break; 2156 default: 2157 llvm_unreachable("Unsupported operation for overflow detection"); 2158 } 2159 OpID <<= 1; 2160 if (isSigned) 2161 OpID |= 1; 2162 2163 llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 2164 2165 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, opTy); 2166 2167 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 2168 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 2169 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 2170 2171 // Handle overflow with llvm.trap if no custom handler has been specified. 2172 const std::string *handlerName = 2173 &CGF.getLangOpts().OverflowHandler; 2174 if (handlerName->empty()) { 2175 // If the signed-integer-overflow sanitizer is enabled, emit a call to its 2176 // runtime. Otherwise, this is a -ftrapv check, so just emit a trap. 2177 if (!isSigned || CGF.SanOpts->SignedIntegerOverflow) 2178 EmitBinOpCheck(Builder.CreateNot(overflow), Ops); 2179 else 2180 CGF.EmitTrapCheck(Builder.CreateNot(overflow)); 2181 return result; 2182 } 2183 2184 // Branch in case of overflow. 2185 llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); 2186 llvm::Function::iterator insertPt = initialBB; 2187 llvm::BasicBlock *continueBB = CGF.createBasicBlock("nooverflow", CGF.CurFn, 2188 llvm::next(insertPt)); 2189 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); 2190 2191 Builder.CreateCondBr(overflow, overflowBB, continueBB); 2192 2193 // If an overflow handler is set, then we want to call it and then use its 2194 // result, if it returns. 2195 Builder.SetInsertPoint(overflowBB); 2196 2197 // Get the overflow handler. 2198 llvm::Type *Int8Ty = CGF.Int8Ty; 2199 llvm::Type *argTypes[] = { CGF.Int64Ty, CGF.Int64Ty, Int8Ty, Int8Ty }; 2200 llvm::FunctionType *handlerTy = 2201 llvm::FunctionType::get(CGF.Int64Ty, argTypes, true); 2202 llvm::Value *handler = CGF.CGM.CreateRuntimeFunction(handlerTy, *handlerName); 2203 2204 // Sign extend the args to 64-bit, so that we can use the same handler for 2205 // all types of overflow. 2206 llvm::Value *lhs = Builder.CreateSExt(Ops.LHS, CGF.Int64Ty); 2207 llvm::Value *rhs = Builder.CreateSExt(Ops.RHS, CGF.Int64Ty); 2208 2209 // Call the handler with the two arguments, the operation, and the size of 2210 // the result. 2211 llvm::Value *handlerArgs[] = { 2212 lhs, 2213 rhs, 2214 Builder.getInt8(OpID), 2215 Builder.getInt8(cast<llvm::IntegerType>(opTy)->getBitWidth()) 2216 }; 2217 llvm::Value *handlerResult = 2218 CGF.EmitNounwindRuntimeCall(handler, handlerArgs); 2219 2220 // Truncate the result back to the desired size. 2221 handlerResult = Builder.CreateTrunc(handlerResult, opTy); 2222 Builder.CreateBr(continueBB); 2223 2224 Builder.SetInsertPoint(continueBB); 2225 llvm::PHINode *phi = Builder.CreatePHI(opTy, 2); 2226 phi->addIncoming(result, initialBB); 2227 phi->addIncoming(handlerResult, overflowBB); 2228 2229 return phi; 2230} 2231 2232/// Emit pointer + index arithmetic. 2233static Value *emitPointerArithmetic(CodeGenFunction &CGF, 2234 const BinOpInfo &op, 2235 bool isSubtraction) { 2236 // Must have binary (not unary) expr here. Unary pointer 2237 // increment/decrement doesn't use this path. 2238 const BinaryOperator *expr = cast<BinaryOperator>(op.E); 2239 2240 Value *pointer = op.LHS; 2241 Expr *pointerOperand = expr->getLHS(); 2242 Value *index = op.RHS; 2243 Expr *indexOperand = expr->getRHS(); 2244 2245 // In a subtraction, the LHS is always the pointer. 2246 if (!isSubtraction && !pointer->getType()->isPointerTy()) { 2247 std::swap(pointer, index); 2248 std::swap(pointerOperand, indexOperand); 2249 } 2250 2251 unsigned width = cast<llvm::IntegerType>(index->getType())->getBitWidth(); 2252 if (width != CGF.PointerWidthInBits) { 2253 // Zero-extend or sign-extend the pointer value according to 2254 // whether the index is signed or not. 2255 bool isSigned = indexOperand->getType()->isSignedIntegerOrEnumerationType(); 2256 index = CGF.Builder.CreateIntCast(index, CGF.PtrDiffTy, isSigned, 2257 "idx.ext"); 2258 } 2259 2260 // If this is subtraction, negate the index. 2261 if (isSubtraction) 2262 index = CGF.Builder.CreateNeg(index, "idx.neg"); 2263 2264 if (CGF.SanOpts->Bounds) 2265 CGF.EmitBoundsCheck(op.E, pointerOperand, index, indexOperand->getType(), 2266 /*Accessed*/ false); 2267 2268 const PointerType *pointerType 2269 = pointerOperand->getType()->getAs<PointerType>(); 2270 if (!pointerType) { 2271 QualType objectType = pointerOperand->getType() 2272 ->castAs<ObjCObjectPointerType>() 2273 ->getPointeeType(); 2274 llvm::Value *objectSize 2275 = CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(objectType)); 2276 2277 index = CGF.Builder.CreateMul(index, objectSize); 2278 2279 Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy); 2280 result = CGF.Builder.CreateGEP(result, index, "add.ptr"); 2281 return CGF.Builder.CreateBitCast(result, pointer->getType()); 2282 } 2283 2284 QualType elementType = pointerType->getPointeeType(); 2285 if (const VariableArrayType *vla 2286 = CGF.getContext().getAsVariableArrayType(elementType)) { 2287 // The element count here is the total number of non-VLA elements. 2288 llvm::Value *numElements = CGF.getVLASize(vla).first; 2289 2290 // Effectively, the multiply by the VLA size is part of the GEP. 2291 // GEP indexes are signed, and scaling an index isn't permitted to 2292 // signed-overflow, so we use the same semantics for our explicit 2293 // multiply. We suppress this if overflow is not undefined behavior. 2294 if (CGF.getLangOpts().isSignedOverflowDefined()) { 2295 index = CGF.Builder.CreateMul(index, numElements, "vla.index"); 2296 pointer = CGF.Builder.CreateGEP(pointer, index, "add.ptr"); 2297 } else { 2298 index = CGF.Builder.CreateNSWMul(index, numElements, "vla.index"); 2299 pointer = CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr"); 2300 } 2301 return pointer; 2302 } 2303 2304 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 2305 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 2306 // future proof. 2307 if (elementType->isVoidType() || elementType->isFunctionType()) { 2308 Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy); 2309 result = CGF.Builder.CreateGEP(result, index, "add.ptr"); 2310 return CGF.Builder.CreateBitCast(result, pointer->getType()); 2311 } 2312 2313 if (CGF.getLangOpts().isSignedOverflowDefined()) 2314 return CGF.Builder.CreateGEP(pointer, index, "add.ptr"); 2315 2316 return CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr"); 2317} 2318 2319// Construct an fmuladd intrinsic to represent a fused mul-add of MulOp and 2320// Addend. Use negMul and negAdd to negate the first operand of the Mul or 2321// the add operand respectively. This allows fmuladd to represent a*b-c, or 2322// c-a*b. Patterns in LLVM should catch the negated forms and translate them to 2323// efficient operations. 2324static Value* buildFMulAdd(llvm::BinaryOperator *MulOp, Value *Addend, 2325 const CodeGenFunction &CGF, CGBuilderTy &Builder, 2326 bool negMul, bool negAdd) { 2327 assert(!(negMul && negAdd) && "Only one of negMul and negAdd should be set."); 2328 2329 Value *MulOp0 = MulOp->getOperand(0); 2330 Value *MulOp1 = MulOp->getOperand(1); 2331 if (negMul) { 2332 MulOp0 = 2333 Builder.CreateFSub( 2334 llvm::ConstantFP::getZeroValueForNegation(MulOp0->getType()), MulOp0, 2335 "neg"); 2336 } else if (negAdd) { 2337 Addend = 2338 Builder.CreateFSub( 2339 llvm::ConstantFP::getZeroValueForNegation(Addend->getType()), Addend, 2340 "neg"); 2341 } 2342 2343 Value *FMulAdd = 2344 Builder.CreateCall3( 2345 CGF.CGM.getIntrinsic(llvm::Intrinsic::fmuladd, Addend->getType()), 2346 MulOp0, MulOp1, Addend); 2347 MulOp->eraseFromParent(); 2348 2349 return FMulAdd; 2350} 2351 2352// Check whether it would be legal to emit an fmuladd intrinsic call to 2353// represent op and if so, build the fmuladd. 2354// 2355// Checks that (a) the operation is fusable, and (b) -ffp-contract=on. 2356// Does NOT check the type of the operation - it's assumed that this function 2357// will be called from contexts where it's known that the type is contractable. 2358static Value* tryEmitFMulAdd(const BinOpInfo &op, 2359 const CodeGenFunction &CGF, CGBuilderTy &Builder, 2360 bool isSub=false) { 2361 2362 assert((op.Opcode == BO_Add || op.Opcode == BO_AddAssign || 2363 op.Opcode == BO_Sub || op.Opcode == BO_SubAssign) && 2364 "Only fadd/fsub can be the root of an fmuladd."); 2365 2366 // Check whether this op is marked as fusable. 2367 if (!op.FPContractable) 2368 return 0; 2369 2370 // Check whether -ffp-contract=on. (If -ffp-contract=off/fast, fusing is 2371 // either disabled, or handled entirely by the LLVM backend). 2372 if (CGF.CGM.getCodeGenOpts().getFPContractMode() != CodeGenOptions::FPC_On) 2373 return 0; 2374 2375 // We have a potentially fusable op. Look for a mul on one of the operands. 2376 if (llvm::BinaryOperator* LHSBinOp = dyn_cast<llvm::BinaryOperator>(op.LHS)) { 2377 if (LHSBinOp->getOpcode() == llvm::Instruction::FMul) { 2378 assert(LHSBinOp->getNumUses() == 0 && 2379 "Operations with multiple uses shouldn't be contracted."); 2380 return buildFMulAdd(LHSBinOp, op.RHS, CGF, Builder, false, isSub); 2381 } 2382 } else if (llvm::BinaryOperator* RHSBinOp = 2383 dyn_cast<llvm::BinaryOperator>(op.RHS)) { 2384 if (RHSBinOp->getOpcode() == llvm::Instruction::FMul) { 2385 assert(RHSBinOp->getNumUses() == 0 && 2386 "Operations with multiple uses shouldn't be contracted."); 2387 return buildFMulAdd(RHSBinOp, op.LHS, CGF, Builder, isSub, false); 2388 } 2389 } 2390 2391 return 0; 2392} 2393 2394Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &op) { 2395 if (op.LHS->getType()->isPointerTy() || 2396 op.RHS->getType()->isPointerTy()) 2397 return emitPointerArithmetic(CGF, op, /*subtraction*/ false); 2398 2399 if (op.Ty->isSignedIntegerOrEnumerationType()) { 2400 switch (CGF.getLangOpts().getSignedOverflowBehavior()) { 2401 case LangOptions::SOB_Defined: 2402 return Builder.CreateAdd(op.LHS, op.RHS, "add"); 2403 case LangOptions::SOB_Undefined: 2404 if (!CGF.SanOpts->SignedIntegerOverflow) 2405 return Builder.CreateNSWAdd(op.LHS, op.RHS, "add"); 2406 // Fall through. 2407 case LangOptions::SOB_Trapping: 2408 return EmitOverflowCheckedBinOp(op); 2409 } 2410 } 2411 2412 if (op.Ty->isUnsignedIntegerType() && CGF.SanOpts->UnsignedIntegerOverflow) 2413 return EmitOverflowCheckedBinOp(op); 2414 2415 if (op.LHS->getType()->isFPOrFPVectorTy()) { 2416 // Try to form an fmuladd. 2417 if (Value *FMulAdd = tryEmitFMulAdd(op, CGF, Builder)) 2418 return FMulAdd; 2419 2420 return Builder.CreateFAdd(op.LHS, op.RHS, "add"); 2421 } 2422 2423 return Builder.CreateAdd(op.LHS, op.RHS, "add"); 2424} 2425 2426Value *ScalarExprEmitter::EmitSub(const BinOpInfo &op) { 2427 // The LHS is always a pointer if either side is. 2428 if (!op.LHS->getType()->isPointerTy()) { 2429 if (op.Ty->isSignedIntegerOrEnumerationType()) { 2430 switch (CGF.getLangOpts().getSignedOverflowBehavior()) { 2431 case LangOptions::SOB_Defined: 2432 return Builder.CreateSub(op.LHS, op.RHS, "sub"); 2433 case LangOptions::SOB_Undefined: 2434 if (!CGF.SanOpts->SignedIntegerOverflow) 2435 return Builder.CreateNSWSub(op.LHS, op.RHS, "sub"); 2436 // Fall through. 2437 case LangOptions::SOB_Trapping: 2438 return EmitOverflowCheckedBinOp(op); 2439 } 2440 } 2441 2442 if (op.Ty->isUnsignedIntegerType() && CGF.SanOpts->UnsignedIntegerOverflow) 2443 return EmitOverflowCheckedBinOp(op); 2444 2445 if (op.LHS->getType()->isFPOrFPVectorTy()) { 2446 // Try to form an fmuladd. 2447 if (Value *FMulAdd = tryEmitFMulAdd(op, CGF, Builder, true)) 2448 return FMulAdd; 2449 return Builder.CreateFSub(op.LHS, op.RHS, "sub"); 2450 } 2451 2452 return Builder.CreateSub(op.LHS, op.RHS, "sub"); 2453 } 2454 2455 // If the RHS is not a pointer, then we have normal pointer 2456 // arithmetic. 2457 if (!op.RHS->getType()->isPointerTy()) 2458 return emitPointerArithmetic(CGF, op, /*subtraction*/ true); 2459 2460 // Otherwise, this is a pointer subtraction. 2461 2462 // Do the raw subtraction part. 2463 llvm::Value *LHS 2464 = Builder.CreatePtrToInt(op.LHS, CGF.PtrDiffTy, "sub.ptr.lhs.cast"); 2465 llvm::Value *RHS 2466 = Builder.CreatePtrToInt(op.RHS, CGF.PtrDiffTy, "sub.ptr.rhs.cast"); 2467 Value *diffInChars = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 2468 2469 // Okay, figure out the element size. 2470 const BinaryOperator *expr = cast<BinaryOperator>(op.E); 2471 QualType elementType = expr->getLHS()->getType()->getPointeeType(); 2472 2473 llvm::Value *divisor = 0; 2474 2475 // For a variable-length array, this is going to be non-constant. 2476 if (const VariableArrayType *vla 2477 = CGF.getContext().getAsVariableArrayType(elementType)) { 2478 llvm::Value *numElements; 2479 llvm::tie(numElements, elementType) = CGF.getVLASize(vla); 2480 2481 divisor = numElements; 2482 2483 // Scale the number of non-VLA elements by the non-VLA element size. 2484 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(elementType); 2485 if (!eltSize.isOne()) 2486 divisor = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), divisor); 2487 2488 // For everything elese, we can just compute it, safe in the 2489 // assumption that Sema won't let anything through that we can't 2490 // safely compute the size of. 2491 } else { 2492 CharUnits elementSize; 2493 // Handle GCC extension for pointer arithmetic on void* and 2494 // function pointer types. 2495 if (elementType->isVoidType() || elementType->isFunctionType()) 2496 elementSize = CharUnits::One(); 2497 else 2498 elementSize = CGF.getContext().getTypeSizeInChars(elementType); 2499 2500 // Don't even emit the divide for element size of 1. 2501 if (elementSize.isOne()) 2502 return diffInChars; 2503 2504 divisor = CGF.CGM.getSize(elementSize); 2505 } 2506 2507 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 2508 // pointer difference in C is only defined in the case where both operands 2509 // are pointing to elements of an array. 2510 return Builder.CreateExactSDiv(diffInChars, divisor, "sub.ptr.div"); 2511} 2512 2513Value *ScalarExprEmitter::GetWidthMinusOneValue(Value* LHS,Value* RHS) { 2514 llvm::IntegerType *Ty; 2515 if (llvm::VectorType *VT = dyn_cast<llvm::VectorType>(LHS->getType())) 2516 Ty = cast<llvm::IntegerType>(VT->getElementType()); 2517 else 2518 Ty = cast<llvm::IntegerType>(LHS->getType()); 2519 return llvm::ConstantInt::get(RHS->getType(), Ty->getBitWidth() - 1); 2520} 2521 2522Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 2523 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 2524 // RHS to the same size as the LHS. 2525 Value *RHS = Ops.RHS; 2526 if (Ops.LHS->getType() != RHS->getType()) 2527 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 2528 2529 if (CGF.SanOpts->Shift && !CGF.getLangOpts().OpenCL && 2530 isa<llvm::IntegerType>(Ops.LHS->getType())) { 2531 llvm::Value *WidthMinusOne = GetWidthMinusOneValue(Ops.LHS, RHS); 2532 llvm::Value *Valid = Builder.CreateICmpULE(RHS, WidthMinusOne); 2533 2534 if (Ops.Ty->hasSignedIntegerRepresentation()) { 2535 llvm::BasicBlock *Orig = Builder.GetInsertBlock(); 2536 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 2537 llvm::BasicBlock *CheckBitsShifted = CGF.createBasicBlock("check"); 2538 Builder.CreateCondBr(Valid, CheckBitsShifted, Cont); 2539 2540 // Check whether we are shifting any non-zero bits off the top of the 2541 // integer. 2542 CGF.EmitBlock(CheckBitsShifted); 2543 llvm::Value *BitsShiftedOff = 2544 Builder.CreateLShr(Ops.LHS, 2545 Builder.CreateSub(WidthMinusOne, RHS, "shl.zeros", 2546 /*NUW*/true, /*NSW*/true), 2547 "shl.check"); 2548 if (CGF.getLangOpts().CPlusPlus) { 2549 // In C99, we are not permitted to shift a 1 bit into the sign bit. 2550 // Under C++11's rules, shifting a 1 bit into the sign bit is 2551 // OK, but shifting a 1 bit out of it is not. (C89 and C++03 don't 2552 // define signed left shifts, so we use the C99 and C++11 rules there). 2553 llvm::Value *One = llvm::ConstantInt::get(BitsShiftedOff->getType(), 1); 2554 BitsShiftedOff = Builder.CreateLShr(BitsShiftedOff, One); 2555 } 2556 llvm::Value *Zero = llvm::ConstantInt::get(BitsShiftedOff->getType(), 0); 2557 llvm::Value *SecondCheck = Builder.CreateICmpEQ(BitsShiftedOff, Zero); 2558 CGF.EmitBlock(Cont); 2559 llvm::PHINode *P = Builder.CreatePHI(Valid->getType(), 2); 2560 P->addIncoming(Valid, Orig); 2561 P->addIncoming(SecondCheck, CheckBitsShifted); 2562 Valid = P; 2563 } 2564 2565 EmitBinOpCheck(Valid, Ops); 2566 } 2567 // OpenCL 6.3j: shift values are effectively % word size of LHS. 2568 if (CGF.getLangOpts().OpenCL) 2569 RHS = Builder.CreateAnd(RHS, GetWidthMinusOneValue(Ops.LHS, RHS), "shl.mask"); 2570 2571 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 2572} 2573 2574Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 2575 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 2576 // RHS to the same size as the LHS. 2577 Value *RHS = Ops.RHS; 2578 if (Ops.LHS->getType() != RHS->getType()) 2579 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 2580 2581 if (CGF.SanOpts->Shift && !CGF.getLangOpts().OpenCL && 2582 isa<llvm::IntegerType>(Ops.LHS->getType())) 2583 EmitBinOpCheck(Builder.CreateICmpULE(RHS, GetWidthMinusOneValue(Ops.LHS, RHS)), Ops); 2584 2585 // OpenCL 6.3j: shift values are effectively % word size of LHS. 2586 if (CGF.getLangOpts().OpenCL) 2587 RHS = Builder.CreateAnd(RHS, GetWidthMinusOneValue(Ops.LHS, RHS), "shr.mask"); 2588 2589 if (Ops.Ty->hasUnsignedIntegerRepresentation()) 2590 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 2591 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 2592} 2593 2594enum IntrinsicType { VCMPEQ, VCMPGT }; 2595// return corresponding comparison intrinsic for given vector type 2596static llvm::Intrinsic::ID GetIntrinsic(IntrinsicType IT, 2597 BuiltinType::Kind ElemKind) { 2598 switch (ElemKind) { 2599 default: llvm_unreachable("unexpected element type"); 2600 case BuiltinType::Char_U: 2601 case BuiltinType::UChar: 2602 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p : 2603 llvm::Intrinsic::ppc_altivec_vcmpgtub_p; 2604 case BuiltinType::Char_S: 2605 case BuiltinType::SChar: 2606 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p : 2607 llvm::Intrinsic::ppc_altivec_vcmpgtsb_p; 2608 case BuiltinType::UShort: 2609 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p : 2610 llvm::Intrinsic::ppc_altivec_vcmpgtuh_p; 2611 case BuiltinType::Short: 2612 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p : 2613 llvm::Intrinsic::ppc_altivec_vcmpgtsh_p; 2614 case BuiltinType::UInt: 2615 case BuiltinType::ULong: 2616 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p : 2617 llvm::Intrinsic::ppc_altivec_vcmpgtuw_p; 2618 case BuiltinType::Int: 2619 case BuiltinType::Long: 2620 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p : 2621 llvm::Intrinsic::ppc_altivec_vcmpgtsw_p; 2622 case BuiltinType::Float: 2623 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpeqfp_p : 2624 llvm::Intrinsic::ppc_altivec_vcmpgtfp_p; 2625 } 2626} 2627 2628Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 2629 unsigned SICmpOpc, unsigned FCmpOpc) { 2630 TestAndClearIgnoreResultAssign(); 2631 Value *Result; 2632 QualType LHSTy = E->getLHS()->getType(); 2633 if (const MemberPointerType *MPT = LHSTy->getAs<MemberPointerType>()) { 2634 assert(E->getOpcode() == BO_EQ || 2635 E->getOpcode() == BO_NE); 2636 Value *LHS = CGF.EmitScalarExpr(E->getLHS()); 2637 Value *RHS = CGF.EmitScalarExpr(E->getRHS()); 2638 Result = CGF.CGM.getCXXABI().EmitMemberPointerComparison( 2639 CGF, LHS, RHS, MPT, E->getOpcode() == BO_NE); 2640 } else if (!LHSTy->isAnyComplexType()) { 2641 Value *LHS = Visit(E->getLHS()); 2642 Value *RHS = Visit(E->getRHS()); 2643 2644 // If AltiVec, the comparison results in a numeric type, so we use 2645 // intrinsics comparing vectors and giving 0 or 1 as a result 2646 if (LHSTy->isVectorType() && !E->getType()->isVectorType()) { 2647 // constants for mapping CR6 register bits to predicate result 2648 enum { CR6_EQ=0, CR6_EQ_REV, CR6_LT, CR6_LT_REV } CR6; 2649 2650 llvm::Intrinsic::ID ID = llvm::Intrinsic::not_intrinsic; 2651 2652 // in several cases vector arguments order will be reversed 2653 Value *FirstVecArg = LHS, 2654 *SecondVecArg = RHS; 2655 2656 QualType ElTy = LHSTy->getAs<VectorType>()->getElementType(); 2657 const BuiltinType *BTy = ElTy->getAs<BuiltinType>(); 2658 BuiltinType::Kind ElementKind = BTy->getKind(); 2659 2660 switch(E->getOpcode()) { 2661 default: llvm_unreachable("is not a comparison operation"); 2662 case BO_EQ: 2663 CR6 = CR6_LT; 2664 ID = GetIntrinsic(VCMPEQ, ElementKind); 2665 break; 2666 case BO_NE: 2667 CR6 = CR6_EQ; 2668 ID = GetIntrinsic(VCMPEQ, ElementKind); 2669 break; 2670 case BO_LT: 2671 CR6 = CR6_LT; 2672 ID = GetIntrinsic(VCMPGT, ElementKind); 2673 std::swap(FirstVecArg, SecondVecArg); 2674 break; 2675 case BO_GT: 2676 CR6 = CR6_LT; 2677 ID = GetIntrinsic(VCMPGT, ElementKind); 2678 break; 2679 case BO_LE: 2680 if (ElementKind == BuiltinType::Float) { 2681 CR6 = CR6_LT; 2682 ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p; 2683 std::swap(FirstVecArg, SecondVecArg); 2684 } 2685 else { 2686 CR6 = CR6_EQ; 2687 ID = GetIntrinsic(VCMPGT, ElementKind); 2688 } 2689 break; 2690 case BO_GE: 2691 if (ElementKind == BuiltinType::Float) { 2692 CR6 = CR6_LT; 2693 ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p; 2694 } 2695 else { 2696 CR6 = CR6_EQ; 2697 ID = GetIntrinsic(VCMPGT, ElementKind); 2698 std::swap(FirstVecArg, SecondVecArg); 2699 } 2700 break; 2701 } 2702 2703 Value *CR6Param = Builder.getInt32(CR6); 2704 llvm::Function *F = CGF.CGM.getIntrinsic(ID); 2705 Result = Builder.CreateCall3(F, CR6Param, FirstVecArg, SecondVecArg, ""); 2706 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 2707 } 2708 2709 if (LHS->getType()->isFPOrFPVectorTy()) { 2710 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 2711 LHS, RHS, "cmp"); 2712 } else if (LHSTy->hasSignedIntegerRepresentation()) { 2713 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 2714 LHS, RHS, "cmp"); 2715 } else { 2716 // Unsigned integers and pointers. 2717 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2718 LHS, RHS, "cmp"); 2719 } 2720 2721 // If this is a vector comparison, sign extend the result to the appropriate 2722 // vector integer type and return it (don't convert to bool). 2723 if (LHSTy->isVectorType()) 2724 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 2725 2726 } else { 2727 // Complex Comparison: can only be an equality comparison. 2728 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 2729 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 2730 2731 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 2732 2733 Value *ResultR, *ResultI; 2734 if (CETy->isRealFloatingType()) { 2735 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 2736 LHS.first, RHS.first, "cmp.r"); 2737 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 2738 LHS.second, RHS.second, "cmp.i"); 2739 } else { 2740 // Complex comparisons can only be equality comparisons. As such, signed 2741 // and unsigned opcodes are the same. 2742 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2743 LHS.first, RHS.first, "cmp.r"); 2744 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2745 LHS.second, RHS.second, "cmp.i"); 2746 } 2747 2748 if (E->getOpcode() == BO_EQ) { 2749 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 2750 } else { 2751 assert(E->getOpcode() == BO_NE && 2752 "Complex comparison other than == or != ?"); 2753 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 2754 } 2755 } 2756 2757 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 2758} 2759 2760Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 2761 bool Ignore = TestAndClearIgnoreResultAssign(); 2762 2763 Value *RHS; 2764 LValue LHS; 2765 2766 switch (E->getLHS()->getType().getObjCLifetime()) { 2767 case Qualifiers::OCL_Strong: 2768 llvm::tie(LHS, RHS) = CGF.EmitARCStoreStrong(E, Ignore); 2769 break; 2770 2771 case Qualifiers::OCL_Autoreleasing: 2772 llvm::tie(LHS,RHS) = CGF.EmitARCStoreAutoreleasing(E); 2773 break; 2774 2775 case Qualifiers::OCL_Weak: 2776 RHS = Visit(E->getRHS()); 2777 LHS = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store); 2778 RHS = CGF.EmitARCStoreWeak(LHS.getAddress(), RHS, Ignore); 2779 break; 2780 2781 // No reason to do any of these differently. 2782 case Qualifiers::OCL_None: 2783 case Qualifiers::OCL_ExplicitNone: 2784 // __block variables need to have the rhs evaluated first, plus 2785 // this should improve codegen just a little. 2786 RHS = Visit(E->getRHS()); 2787 LHS = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store); 2788 2789 // Store the value into the LHS. Bit-fields are handled specially 2790 // because the result is altered by the store, i.e., [C99 6.5.16p1] 2791 // 'An assignment expression has the value of the left operand after 2792 // the assignment...'. 2793 if (LHS.isBitField()) 2794 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, &RHS); 2795 else 2796 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS); 2797 } 2798 2799 // If the result is clearly ignored, return now. 2800 if (Ignore) 2801 return 0; 2802 2803 // The result of an assignment in C is the assigned r-value. 2804 if (!CGF.getLangOpts().CPlusPlus) 2805 return RHS; 2806 2807 // If the lvalue is non-volatile, return the computed value of the assignment. 2808 if (!LHS.isVolatileQualified()) 2809 return RHS; 2810 2811 // Otherwise, reload the value. 2812 return EmitLoadOfLValue(LHS); 2813} 2814 2815Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 2816 // Perform vector logical and on comparisons with zero vectors. 2817 if (E->getType()->isVectorType()) { 2818 Value *LHS = Visit(E->getLHS()); 2819 Value *RHS = Visit(E->getRHS()); 2820 Value *Zero = llvm::ConstantAggregateZero::get(LHS->getType()); 2821 if (LHS->getType()->isFPOrFPVectorTy()) { 2822 LHS = Builder.CreateFCmp(llvm::CmpInst::FCMP_UNE, LHS, Zero, "cmp"); 2823 RHS = Builder.CreateFCmp(llvm::CmpInst::FCMP_UNE, RHS, Zero, "cmp"); 2824 } else { 2825 LHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, LHS, Zero, "cmp"); 2826 RHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, RHS, Zero, "cmp"); 2827 } 2828 Value *And = Builder.CreateAnd(LHS, RHS); 2829 return Builder.CreateSExt(And, ConvertType(E->getType()), "sext"); 2830 } 2831 2832 llvm::Type *ResTy = ConvertType(E->getType()); 2833 2834 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 2835 // If we have 1 && X, just emit X without inserting the control flow. 2836 bool LHSCondVal; 2837 if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) { 2838 if (LHSCondVal) { // If we have 1 && X, just emit X. 2839 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2840 // ZExt result to int or bool. 2841 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 2842 } 2843 2844 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 2845 if (!CGF.ContainsLabel(E->getRHS())) 2846 return llvm::Constant::getNullValue(ResTy); 2847 } 2848 2849 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 2850 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 2851 2852 CodeGenFunction::ConditionalEvaluation eval(CGF); 2853 2854 // Branch on the LHS first. If it is false, go to the failure (cont) block. 2855 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 2856 2857 // Any edges into the ContBlock are now from an (indeterminate number of) 2858 // edges from this first condition. All of these values will be false. Start 2859 // setting up the PHI node in the Cont Block for this. 2860 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2, 2861 "", ContBlock); 2862 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 2863 PI != PE; ++PI) 2864 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 2865 2866 eval.begin(CGF); 2867 CGF.EmitBlock(RHSBlock); 2868 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2869 eval.end(CGF); 2870 2871 // Reaquire the RHS block, as there may be subblocks inserted. 2872 RHSBlock = Builder.GetInsertBlock(); 2873 2874 // Emit an unconditional branch from this block to ContBlock. Insert an entry 2875 // into the phi node for the edge with the value of RHSCond. 2876 if (CGF.getDebugInfo()) 2877 // There is no need to emit line number for unconditional branch. 2878 Builder.SetCurrentDebugLocation(llvm::DebugLoc()); 2879 CGF.EmitBlock(ContBlock); 2880 PN->addIncoming(RHSCond, RHSBlock); 2881 2882 // ZExt result to int. 2883 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); 2884} 2885 2886Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 2887 // Perform vector logical or on comparisons with zero vectors. 2888 if (E->getType()->isVectorType()) { 2889 Value *LHS = Visit(E->getLHS()); 2890 Value *RHS = Visit(E->getRHS()); 2891 Value *Zero = llvm::ConstantAggregateZero::get(LHS->getType()); 2892 if (LHS->getType()->isFPOrFPVectorTy()) { 2893 LHS = Builder.CreateFCmp(llvm::CmpInst::FCMP_UNE, LHS, Zero, "cmp"); 2894 RHS = Builder.CreateFCmp(llvm::CmpInst::FCMP_UNE, RHS, Zero, "cmp"); 2895 } else { 2896 LHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, LHS, Zero, "cmp"); 2897 RHS = Builder.CreateICmp(llvm::CmpInst::ICMP_NE, RHS, Zero, "cmp"); 2898 } 2899 Value *Or = Builder.CreateOr(LHS, RHS); 2900 return Builder.CreateSExt(Or, ConvertType(E->getType()), "sext"); 2901 } 2902 2903 llvm::Type *ResTy = ConvertType(E->getType()); 2904 2905 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 2906 // If we have 0 || X, just emit X without inserting the control flow. 2907 bool LHSCondVal; 2908 if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) { 2909 if (!LHSCondVal) { // If we have 0 || X, just emit X. 2910 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2911 // ZExt result to int or bool. 2912 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 2913 } 2914 2915 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 2916 if (!CGF.ContainsLabel(E->getRHS())) 2917 return llvm::ConstantInt::get(ResTy, 1); 2918 } 2919 2920 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 2921 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 2922 2923 CodeGenFunction::ConditionalEvaluation eval(CGF); 2924 2925 // Branch on the LHS first. If it is true, go to the success (cont) block. 2926 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 2927 2928 // Any edges into the ContBlock are now from an (indeterminate number of) 2929 // edges from this first condition. All of these values will be true. Start 2930 // setting up the PHI node in the Cont Block for this. 2931 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2, 2932 "", ContBlock); 2933 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 2934 PI != PE; ++PI) 2935 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 2936 2937 eval.begin(CGF); 2938 2939 // Emit the RHS condition as a bool value. 2940 CGF.EmitBlock(RHSBlock); 2941 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2942 2943 eval.end(CGF); 2944 2945 // Reaquire the RHS block, as there may be subblocks inserted. 2946 RHSBlock = Builder.GetInsertBlock(); 2947 2948 // Emit an unconditional branch from this block to ContBlock. Insert an entry 2949 // into the phi node for the edge with the value of RHSCond. 2950 CGF.EmitBlock(ContBlock); 2951 PN->addIncoming(RHSCond, RHSBlock); 2952 2953 // ZExt result to int. 2954 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 2955} 2956 2957Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 2958 CGF.EmitIgnoredExpr(E->getLHS()); 2959 CGF.EnsureInsertPoint(); 2960 return Visit(E->getRHS()); 2961} 2962 2963//===----------------------------------------------------------------------===// 2964// Other Operators 2965//===----------------------------------------------------------------------===// 2966 2967/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 2968/// expression is cheap enough and side-effect-free enough to evaluate 2969/// unconditionally instead of conditionally. This is used to convert control 2970/// flow into selects in some cases. 2971static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 2972 CodeGenFunction &CGF) { 2973 E = E->IgnoreParens(); 2974 2975 // Anything that is an integer or floating point constant is fine. 2976 if (E->isConstantInitializer(CGF.getContext(), false)) 2977 return true; 2978 2979 // Non-volatile automatic variables too, to get "cond ? X : Y" where 2980 // X and Y are local variables. 2981 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 2982 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 2983 if (VD->hasLocalStorage() && !(CGF.getContext() 2984 .getCanonicalType(VD->getType()) 2985 .isVolatileQualified())) 2986 return true; 2987 2988 return false; 2989} 2990 2991 2992Value *ScalarExprEmitter:: 2993VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) { 2994 TestAndClearIgnoreResultAssign(); 2995 2996 // Bind the common expression if necessary. 2997 CodeGenFunction::OpaqueValueMapping binding(CGF, E); 2998 2999 Expr *condExpr = E->getCond(); 3000 Expr *lhsExpr = E->getTrueExpr(); 3001 Expr *rhsExpr = E->getFalseExpr(); 3002 3003 // If the condition constant folds and can be elided, try to avoid emitting 3004 // the condition and the dead arm. 3005 bool CondExprBool; 3006 if (CGF.ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) { 3007 Expr *live = lhsExpr, *dead = rhsExpr; 3008 if (!CondExprBool) std::swap(live, dead); 3009 3010 // If the dead side doesn't have labels we need, just emit the Live part. 3011 if (!CGF.ContainsLabel(dead)) { 3012 Value *Result = Visit(live); 3013 3014 // If the live part is a throw expression, it acts like it has a void 3015 // type, so evaluating it returns a null Value*. However, a conditional 3016 // with non-void type must return a non-null Value*. 3017 if (!Result && !E->getType()->isVoidType()) 3018 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType())); 3019 3020 return Result; 3021 } 3022 } 3023 3024 // OpenCL: If the condition is a vector, we can treat this condition like 3025 // the select function. 3026 if (CGF.getLangOpts().OpenCL 3027 && condExpr->getType()->isVectorType()) { 3028 llvm::Value *CondV = CGF.EmitScalarExpr(condExpr); 3029 llvm::Value *LHS = Visit(lhsExpr); 3030 llvm::Value *RHS = Visit(rhsExpr); 3031 3032 llvm::Type *condType = ConvertType(condExpr->getType()); 3033 llvm::VectorType *vecTy = cast<llvm::VectorType>(condType); 3034 3035 unsigned numElem = vecTy->getNumElements(); 3036 llvm::Type *elemType = vecTy->getElementType(); 3037 3038 llvm::Value *zeroVec = llvm::Constant::getNullValue(vecTy); 3039 llvm::Value *TestMSB = Builder.CreateICmpSLT(CondV, zeroVec); 3040 llvm::Value *tmp = Builder.CreateSExt(TestMSB, 3041 llvm::VectorType::get(elemType, 3042 numElem), 3043 "sext"); 3044 llvm::Value *tmp2 = Builder.CreateNot(tmp); 3045 3046 // Cast float to int to perform ANDs if necessary. 3047 llvm::Value *RHSTmp = RHS; 3048 llvm::Value *LHSTmp = LHS; 3049 bool wasCast = false; 3050 llvm::VectorType *rhsVTy = cast<llvm::VectorType>(RHS->getType()); 3051 if (rhsVTy->getElementType()->isFloatingPointTy()) { 3052 RHSTmp = Builder.CreateBitCast(RHS, tmp2->getType()); 3053 LHSTmp = Builder.CreateBitCast(LHS, tmp->getType()); 3054 wasCast = true; 3055 } 3056 3057 llvm::Value *tmp3 = Builder.CreateAnd(RHSTmp, tmp2); 3058 llvm::Value *tmp4 = Builder.CreateAnd(LHSTmp, tmp); 3059 llvm::Value *tmp5 = Builder.CreateOr(tmp3, tmp4, "cond"); 3060 if (wasCast) 3061 tmp5 = Builder.CreateBitCast(tmp5, RHS->getType()); 3062 3063 return tmp5; 3064 } 3065 3066 // If this is a really simple expression (like x ? 4 : 5), emit this as a 3067 // select instead of as control flow. We can only do this if it is cheap and 3068 // safe to evaluate the LHS and RHS unconditionally. 3069 if (isCheapEnoughToEvaluateUnconditionally(lhsExpr, CGF) && 3070 isCheapEnoughToEvaluateUnconditionally(rhsExpr, CGF)) { 3071 llvm::Value *CondV = CGF.EvaluateExprAsBool(condExpr); 3072 llvm::Value *LHS = Visit(lhsExpr); 3073 llvm::Value *RHS = Visit(rhsExpr); 3074 if (!LHS) { 3075 // If the conditional has void type, make sure we return a null Value*. 3076 assert(!RHS && "LHS and RHS types must match"); 3077 return 0; 3078 } 3079 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 3080 } 3081 3082 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 3083 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 3084 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 3085 3086 CodeGenFunction::ConditionalEvaluation eval(CGF); 3087 CGF.EmitBranchOnBoolExpr(condExpr, LHSBlock, RHSBlock); 3088 3089 CGF.EmitBlock(LHSBlock); 3090 eval.begin(CGF); 3091 Value *LHS = Visit(lhsExpr); 3092 eval.end(CGF); 3093 3094 LHSBlock = Builder.GetInsertBlock(); 3095 Builder.CreateBr(ContBlock); 3096 3097 CGF.EmitBlock(RHSBlock); 3098 eval.begin(CGF); 3099 Value *RHS = Visit(rhsExpr); 3100 eval.end(CGF); 3101 3102 RHSBlock = Builder.GetInsertBlock(); 3103 CGF.EmitBlock(ContBlock); 3104 3105 // If the LHS or RHS is a throw expression, it will be legitimately null. 3106 if (!LHS) 3107 return RHS; 3108 if (!RHS) 3109 return LHS; 3110 3111 // Create a PHI node for the real part. 3112 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), 2, "cond"); 3113 PN->addIncoming(LHS, LHSBlock); 3114 PN->addIncoming(RHS, RHSBlock); 3115 return PN; 3116} 3117 3118Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 3119 return Visit(E->getChosenSubExpr(CGF.getContext())); 3120} 3121 3122Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 3123 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 3124 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 3125 3126 // If EmitVAArg fails, we fall back to the LLVM instruction. 3127 if (!ArgPtr) 3128 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 3129 3130 // FIXME Volatility. 3131 return Builder.CreateLoad(ArgPtr); 3132} 3133 3134Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *block) { 3135 return CGF.EmitBlockLiteral(block); 3136} 3137 3138Value *ScalarExprEmitter::VisitAsTypeExpr(AsTypeExpr *E) { 3139 Value *Src = CGF.EmitScalarExpr(E->getSrcExpr()); 3140 llvm::Type *DstTy = ConvertType(E->getType()); 3141 3142 // Going from vec4->vec3 or vec3->vec4 is a special case and requires 3143 // a shuffle vector instead of a bitcast. 3144 llvm::Type *SrcTy = Src->getType(); 3145 if (isa<llvm::VectorType>(DstTy) && isa<llvm::VectorType>(SrcTy)) { 3146 unsigned numElementsDst = cast<llvm::VectorType>(DstTy)->getNumElements(); 3147 unsigned numElementsSrc = cast<llvm::VectorType>(SrcTy)->getNumElements(); 3148 if ((numElementsDst == 3 && numElementsSrc == 4) 3149 || (numElementsDst == 4 && numElementsSrc == 3)) { 3150 3151 3152 // In the case of going from int4->float3, a bitcast is needed before 3153 // doing a shuffle. 3154 llvm::Type *srcElemTy = 3155 cast<llvm::VectorType>(SrcTy)->getElementType(); 3156 llvm::Type *dstElemTy = 3157 cast<llvm::VectorType>(DstTy)->getElementType(); 3158 3159 if ((srcElemTy->isIntegerTy() && dstElemTy->isFloatTy()) 3160 || (srcElemTy->isFloatTy() && dstElemTy->isIntegerTy())) { 3161 // Create a float type of the same size as the source or destination. 3162 llvm::VectorType *newSrcTy = llvm::VectorType::get(dstElemTy, 3163 numElementsSrc); 3164 3165 Src = Builder.CreateBitCast(Src, newSrcTy, "astypeCast"); 3166 } 3167 3168 llvm::Value *UnV = llvm::UndefValue::get(Src->getType()); 3169 3170 SmallVector<llvm::Constant*, 3> Args; 3171 Args.push_back(Builder.getInt32(0)); 3172 Args.push_back(Builder.getInt32(1)); 3173 Args.push_back(Builder.getInt32(2)); 3174 3175 if (numElementsDst == 4) 3176 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 3177 3178 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 3179 3180 return Builder.CreateShuffleVector(Src, UnV, Mask, "astype"); 3181 } 3182 } 3183 3184 return Builder.CreateBitCast(Src, DstTy, "astype"); 3185} 3186 3187Value *ScalarExprEmitter::VisitAtomicExpr(AtomicExpr *E) { 3188 return CGF.EmitAtomicExpr(E).getScalarVal(); 3189} 3190 3191//===----------------------------------------------------------------------===// 3192// Entry Point into this File 3193//===----------------------------------------------------------------------===// 3194 3195/// EmitScalarExpr - Emit the computation of the specified expression of scalar 3196/// type, ignoring the result. 3197Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 3198 assert(E && hasScalarEvaluationKind(E->getType()) && 3199 "Invalid scalar expression to emit"); 3200 3201 if (isa<CXXDefaultArgExpr>(E)) 3202 disableDebugInfo(); 3203 Value *V = ScalarExprEmitter(*this, IgnoreResultAssign) 3204 .Visit(const_cast<Expr*>(E)); 3205 if (isa<CXXDefaultArgExpr>(E)) 3206 enableDebugInfo(); 3207 return V; 3208} 3209 3210/// EmitScalarConversion - Emit a conversion from the specified type to the 3211/// specified destination type, both of which are LLVM scalar types. 3212Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 3213 QualType DstTy) { 3214 assert(hasScalarEvaluationKind(SrcTy) && hasScalarEvaluationKind(DstTy) && 3215 "Invalid scalar expression to emit"); 3216 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 3217} 3218 3219/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 3220/// type to the specified destination type, where the destination type is an 3221/// LLVM scalar type. 3222Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 3223 QualType SrcTy, 3224 QualType DstTy) { 3225 assert(SrcTy->isAnyComplexType() && hasScalarEvaluationKind(DstTy) && 3226 "Invalid complex -> scalar conversion"); 3227 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 3228 DstTy); 3229} 3230 3231 3232llvm::Value *CodeGenFunction:: 3233EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 3234 bool isInc, bool isPre) { 3235 return ScalarExprEmitter(*this).EmitScalarPrePostIncDec(E, LV, isInc, isPre); 3236} 3237 3238LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) { 3239 llvm::Value *V; 3240 // object->isa or (*object).isa 3241 // Generate code as for: *(Class*)object 3242 // build Class* type 3243 llvm::Type *ClassPtrTy = ConvertType(E->getType()); 3244 3245 Expr *BaseExpr = E->getBase(); 3246 if (BaseExpr->isRValue()) { 3247 V = CreateMemTemp(E->getType(), "resval"); 3248 llvm::Value *Src = EmitScalarExpr(BaseExpr); 3249 Builder.CreateStore(Src, V); 3250 V = ScalarExprEmitter(*this).EmitLoadOfLValue( 3251 MakeNaturalAlignAddrLValue(V, E->getType())); 3252 } else { 3253 if (E->isArrow()) 3254 V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr); 3255 else 3256 V = EmitLValue(BaseExpr).getAddress(); 3257 } 3258 3259 // build Class* type 3260 ClassPtrTy = ClassPtrTy->getPointerTo(); 3261 V = Builder.CreateBitCast(V, ClassPtrTy); 3262 return MakeNaturalAlignAddrLValue(V, E->getType()); 3263} 3264 3265 3266LValue CodeGenFunction::EmitCompoundAssignmentLValue( 3267 const CompoundAssignOperator *E) { 3268 ScalarExprEmitter Scalar(*this); 3269 Value *Result = 0; 3270 switch (E->getOpcode()) { 3271#define COMPOUND_OP(Op) \ 3272 case BO_##Op##Assign: \ 3273 return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \ 3274 Result) 3275 COMPOUND_OP(Mul); 3276 COMPOUND_OP(Div); 3277 COMPOUND_OP(Rem); 3278 COMPOUND_OP(Add); 3279 COMPOUND_OP(Sub); 3280 COMPOUND_OP(Shl); 3281 COMPOUND_OP(Shr); 3282 COMPOUND_OP(And); 3283 COMPOUND_OP(Xor); 3284 COMPOUND_OP(Or); 3285#undef COMPOUND_OP 3286 3287 case BO_PtrMemD: 3288 case BO_PtrMemI: 3289 case BO_Mul: 3290 case BO_Div: 3291 case BO_Rem: 3292 case BO_Add: 3293 case BO_Sub: 3294 case BO_Shl: 3295 case BO_Shr: 3296 case BO_LT: 3297 case BO_GT: 3298 case BO_LE: 3299 case BO_GE: 3300 case BO_EQ: 3301 case BO_NE: 3302 case BO_And: 3303 case BO_Xor: 3304 case BO_Or: 3305 case BO_LAnd: 3306 case BO_LOr: 3307 case BO_Assign: 3308 case BO_Comma: 3309 llvm_unreachable("Not valid compound assignment operators"); 3310 } 3311 3312 llvm_unreachable("Unhandled compound assignment operator"); 3313} 3314