CGExprScalar.cpp revision 5d743fa747281dbecbc0d557035ca44f8a26a342
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 "CGObjCRuntime.h" 16#include "CodeGenModule.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/AST/DeclObjC.h" 19#include "clang/AST/RecordLayout.h" 20#include "clang/AST/StmtVisitor.h" 21#include "clang/Basic/TargetInfo.h" 22#include "llvm/Constants.h" 23#include "llvm/Function.h" 24#include "llvm/GlobalVariable.h" 25#include "llvm/Intrinsics.h" 26#include "llvm/Module.h" 27#include "llvm/Support/CFG.h" 28#include "llvm/Target/TargetData.h" 29#include <cstdarg> 30 31using namespace clang; 32using namespace CodeGen; 33using llvm::Value; 34 35//===----------------------------------------------------------------------===// 36// Scalar Expression Emitter 37//===----------------------------------------------------------------------===// 38 39struct BinOpInfo { 40 Value *LHS; 41 Value *RHS; 42 QualType Ty; // Computation Type. 43 BinaryOperator::Opcode Opcode; // Opcode of BinOp to perform 44 const Expr *E; // Entire expr, for error unsupported. May not be binop. 45}; 46 47namespace { 48class ScalarExprEmitter 49 : public StmtVisitor<ScalarExprEmitter, Value*> { 50 CodeGenFunction &CGF; 51 CGBuilderTy &Builder; 52 bool IgnoreResultAssign; 53 llvm::LLVMContext &VMContext; 54public: 55 56 ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false) 57 : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira), 58 VMContext(cgf.getLLVMContext()) { 59 } 60 61 //===--------------------------------------------------------------------===// 62 // Utilities 63 //===--------------------------------------------------------------------===// 64 65 bool TestAndClearIgnoreResultAssign() { 66 bool I = IgnoreResultAssign; 67 IgnoreResultAssign = false; 68 return I; 69 } 70 71 const llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); } 72 LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); } 73 LValue EmitCheckedLValue(const Expr *E) { return CGF.EmitCheckedLValue(E); } 74 75 Value *EmitLoadOfLValue(LValue LV, QualType T) { 76 return CGF.EmitLoadOfLValue(LV, T).getScalarVal(); 77 } 78 79 /// EmitLoadOfLValue - Given an expression with complex type that represents a 80 /// value l-value, this method emits the address of the l-value, then loads 81 /// and returns the result. 82 Value *EmitLoadOfLValue(const Expr *E) { 83 return EmitLoadOfLValue(EmitCheckedLValue(E), E->getType()); 84 } 85 86 /// EmitConversionToBool - Convert the specified expression value to a 87 /// boolean (i1) truth value. This is equivalent to "Val != 0". 88 Value *EmitConversionToBool(Value *Src, QualType DstTy); 89 90 /// EmitScalarConversion - Emit a conversion from the specified type to the 91 /// specified destination type, both of which are LLVM scalar types. 92 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); 93 94 /// EmitComplexToScalarConversion - Emit a conversion from the specified 95 /// complex type to the specified destination type, where the destination type 96 /// is an LLVM scalar type. 97 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 98 QualType SrcTy, QualType DstTy); 99 100 /// EmitNullValue - Emit a value that corresponds to null for the given type. 101 Value *EmitNullValue(QualType Ty); 102 103 //===--------------------------------------------------------------------===// 104 // Visitor Methods 105 //===--------------------------------------------------------------------===// 106 107 Value *VisitStmt(Stmt *S) { 108 S->dump(CGF.getContext().getSourceManager()); 109 assert(0 && "Stmt can't have complex result type!"); 110 return 0; 111 } 112 Value *VisitExpr(Expr *S); 113 114 Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); } 115 116 // Leaves. 117 Value *VisitIntegerLiteral(const IntegerLiteral *E) { 118 return llvm::ConstantInt::get(VMContext, E->getValue()); 119 } 120 Value *VisitFloatingLiteral(const FloatingLiteral *E) { 121 return llvm::ConstantFP::get(VMContext, E->getValue()); 122 } 123 Value *VisitCharacterLiteral(const CharacterLiteral *E) { 124 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 125 } 126 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 127 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 128 } 129 Value *VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) { 130 return EmitNullValue(E->getType()); 131 } 132 Value *VisitGNUNullExpr(const GNUNullExpr *E) { 133 return EmitNullValue(E->getType()); 134 } 135 Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { 136 return llvm::ConstantInt::get(ConvertType(E->getType()), 137 CGF.getContext().typesAreCompatible( 138 E->getArgType1(), E->getArgType2())); 139 } 140 Value *VisitOffsetOfExpr(OffsetOfExpr *E); 141 Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); 142 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 143 llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel()); 144 return Builder.CreateBitCast(V, ConvertType(E->getType())); 145 } 146 147 // l-values. 148 Value *VisitDeclRefExpr(DeclRefExpr *E) { 149 Expr::EvalResult Result; 150 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 151 assert(!Result.HasSideEffects && "Constant declref with side-effect?!"); 152 llvm::ConstantInt *CI 153 = llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 154 CGF.EmitDeclRefExprDbgValue(E, CI); 155 return CI; 156 } 157 return EmitLoadOfLValue(E); 158 } 159 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 160 return CGF.EmitObjCSelectorExpr(E); 161 } 162 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 163 return CGF.EmitObjCProtocolExpr(E); 164 } 165 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 166 return EmitLoadOfLValue(E); 167 } 168 Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { 169 return EmitLoadOfLValue(E); 170 } 171 Value *VisitObjCImplicitSetterGetterRefExpr( 172 ObjCImplicitSetterGetterRefExpr *E) { 173 return EmitLoadOfLValue(E); 174 } 175 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 176 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 177 } 178 179 Value *VisitObjCIsaExpr(ObjCIsaExpr *E) { 180 LValue LV = CGF.EmitObjCIsaExpr(E); 181 Value *V = CGF.EmitLoadOfLValue(LV, E->getType()).getScalarVal(); 182 return V; 183 } 184 185 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 186 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 187 Value *VisitMemberExpr(MemberExpr *E); 188 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 189 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 190 return EmitLoadOfLValue(E); 191 } 192 193 Value *VisitInitListExpr(InitListExpr *E); 194 195 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { 196 return CGF.CGM.EmitNullConstant(E->getType()); 197 } 198 Value *VisitCastExpr(CastExpr *E) { 199 // Make sure to evaluate VLA bounds now so that we have them for later. 200 if (E->getType()->isVariablyModifiedType()) 201 CGF.EmitVLASize(E->getType()); 202 203 return EmitCastExpr(E); 204 } 205 Value *EmitCastExpr(CastExpr *E); 206 207 Value *VisitCallExpr(const CallExpr *E) { 208 if (E->getCallReturnType()->isReferenceType()) 209 return EmitLoadOfLValue(E); 210 211 return CGF.EmitCallExpr(E).getScalarVal(); 212 } 213 214 Value *VisitStmtExpr(const StmtExpr *E); 215 216 Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E); 217 218 // Unary Operators. 219 Value *VisitUnaryPostDec(const UnaryOperator *E) { 220 LValue LV = EmitLValue(E->getSubExpr()); 221 return EmitScalarPrePostIncDec(E, LV, false, false); 222 } 223 Value *VisitUnaryPostInc(const UnaryOperator *E) { 224 LValue LV = EmitLValue(E->getSubExpr()); 225 return EmitScalarPrePostIncDec(E, LV, true, false); 226 } 227 Value *VisitUnaryPreDec(const UnaryOperator *E) { 228 LValue LV = EmitLValue(E->getSubExpr()); 229 return EmitScalarPrePostIncDec(E, LV, false, true); 230 } 231 Value *VisitUnaryPreInc(const UnaryOperator *E) { 232 LValue LV = EmitLValue(E->getSubExpr()); 233 return EmitScalarPrePostIncDec(E, LV, true, true); 234 } 235 236 llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 237 bool isInc, bool isPre); 238 239 240 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 241 // If the sub-expression is an instance member reference, 242 // EmitDeclRefLValue will magically emit it with the appropriate 243 // value as the "address". 244 return EmitLValue(E->getSubExpr()).getAddress(); 245 } 246 Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } 247 Value *VisitUnaryPlus(const UnaryOperator *E) { 248 // This differs from gcc, though, most likely due to a bug in gcc. 249 TestAndClearIgnoreResultAssign(); 250 return Visit(E->getSubExpr()); 251 } 252 Value *VisitUnaryMinus (const UnaryOperator *E); 253 Value *VisitUnaryNot (const UnaryOperator *E); 254 Value *VisitUnaryLNot (const UnaryOperator *E); 255 Value *VisitUnaryReal (const UnaryOperator *E); 256 Value *VisitUnaryImag (const UnaryOperator *E); 257 Value *VisitUnaryExtension(const UnaryOperator *E) { 258 return Visit(E->getSubExpr()); 259 } 260 261 // C++ 262 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 263 return Visit(DAE->getExpr()); 264 } 265 Value *VisitCXXThisExpr(CXXThisExpr *TE) { 266 return CGF.LoadCXXThis(); 267 } 268 269 Value *VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) { 270 return CGF.EmitCXXExprWithTemporaries(E).getScalarVal(); 271 } 272 Value *VisitCXXNewExpr(const CXXNewExpr *E) { 273 return CGF.EmitCXXNewExpr(E); 274 } 275 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { 276 CGF.EmitCXXDeleteExpr(E); 277 return 0; 278 } 279 Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) { 280 return llvm::ConstantInt::get(Builder.getInt1Ty(), 281 E->EvaluateTrait(CGF.getContext())); 282 } 283 284 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { 285 // C++ [expr.pseudo]p1: 286 // The result shall only be used as the operand for the function call 287 // operator (), and the result of such a call has type void. The only 288 // effect is the evaluation of the postfix-expression before the dot or 289 // arrow. 290 CGF.EmitScalarExpr(E->getBase()); 291 return 0; 292 } 293 294 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { 295 return EmitNullValue(E->getType()); 296 } 297 298 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { 299 CGF.EmitCXXThrowExpr(E); 300 return 0; 301 } 302 303 // Binary Operators. 304 Value *EmitMul(const BinOpInfo &Ops) { 305 if (Ops.Ty->hasSignedIntegerRepresentation()) { 306 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 307 case LangOptions::SOB_Undefined: 308 return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul"); 309 case LangOptions::SOB_Defined: 310 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 311 case LangOptions::SOB_Trapping: 312 return EmitOverflowCheckedBinOp(Ops); 313 } 314 } 315 316 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 317 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 318 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 319 } 320 /// Create a binary op that checks for overflow. 321 /// Currently only supports +, - and *. 322 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 323 Value *EmitDiv(const BinOpInfo &Ops); 324 Value *EmitRem(const BinOpInfo &Ops); 325 Value *EmitAdd(const BinOpInfo &Ops); 326 Value *EmitSub(const BinOpInfo &Ops); 327 Value *EmitShl(const BinOpInfo &Ops); 328 Value *EmitShr(const BinOpInfo &Ops); 329 Value *EmitAnd(const BinOpInfo &Ops) { 330 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 331 } 332 Value *EmitXor(const BinOpInfo &Ops) { 333 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 334 } 335 Value *EmitOr (const BinOpInfo &Ops) { 336 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 337 } 338 339 BinOpInfo EmitBinOps(const BinaryOperator *E); 340 LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E, 341 Value *(ScalarExprEmitter::*F)(const BinOpInfo &), 342 Value *&Result); 343 344 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 345 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 346 347 // Binary operators and binary compound assignment operators. 348#define HANDLEBINOP(OP) \ 349 Value *VisitBin ## OP(const BinaryOperator *E) { \ 350 return Emit ## OP(EmitBinOps(E)); \ 351 } \ 352 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 353 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 354 } 355 HANDLEBINOP(Mul) 356 HANDLEBINOP(Div) 357 HANDLEBINOP(Rem) 358 HANDLEBINOP(Add) 359 HANDLEBINOP(Sub) 360 HANDLEBINOP(Shl) 361 HANDLEBINOP(Shr) 362 HANDLEBINOP(And) 363 HANDLEBINOP(Xor) 364 HANDLEBINOP(Or) 365#undef HANDLEBINOP 366 367 // Comparisons. 368 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 369 unsigned SICmpOpc, unsigned FCmpOpc); 370#define VISITCOMP(CODE, UI, SI, FP) \ 371 Value *VisitBin##CODE(const BinaryOperator *E) { \ 372 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 373 llvm::FCmpInst::FP); } 374 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT) 375 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT) 376 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE) 377 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE) 378 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ) 379 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE) 380#undef VISITCOMP 381 382 Value *VisitBinAssign (const BinaryOperator *E); 383 384 Value *VisitBinLAnd (const BinaryOperator *E); 385 Value *VisitBinLOr (const BinaryOperator *E); 386 Value *VisitBinComma (const BinaryOperator *E); 387 388 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } 389 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); } 390 391 // Other Operators. 392 Value *VisitBlockExpr(const BlockExpr *BE); 393 Value *VisitConditionalOperator(const ConditionalOperator *CO); 394 Value *VisitChooseExpr(ChooseExpr *CE); 395 Value *VisitVAArgExpr(VAArgExpr *VE); 396 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 397 return CGF.EmitObjCStringLiteral(E); 398 } 399}; 400} // end anonymous namespace. 401 402//===----------------------------------------------------------------------===// 403// Utilities 404//===----------------------------------------------------------------------===// 405 406/// EmitConversionToBool - Convert the specified expression value to a 407/// boolean (i1) truth value. This is equivalent to "Val != 0". 408Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 409 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs"); 410 411 if (SrcType->isRealFloatingType()) { 412 // Compare against 0.0 for fp scalars. 413 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 414 return Builder.CreateFCmpUNE(Src, Zero, "tobool"); 415 } 416 417 if (const MemberPointerType *MPT = dyn_cast<MemberPointerType>(SrcType)) 418 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, Src, MPT); 419 420 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 421 "Unknown scalar type to convert"); 422 423 // Because of the type rules of C, we often end up computing a logical value, 424 // then zero extending it to int, then wanting it as a logical value again. 425 // Optimize this common case. 426 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) { 427 if (ZI->getOperand(0)->getType() == 428 llvm::Type::getInt1Ty(CGF.getLLVMContext())) { 429 Value *Result = ZI->getOperand(0); 430 // If there aren't any more uses, zap the instruction to save space. 431 // Note that there can be more uses, for example if this 432 // is the result of an assignment. 433 if (ZI->use_empty()) 434 ZI->eraseFromParent(); 435 return Result; 436 } 437 } 438 439 // Compare against an integer or pointer null. 440 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 441 return Builder.CreateICmpNE(Src, Zero, "tobool"); 442} 443 444/// EmitScalarConversion - Emit a conversion from the specified type to the 445/// specified destination type, both of which are LLVM scalar types. 446Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 447 QualType DstType) { 448 SrcType = CGF.getContext().getCanonicalType(SrcType); 449 DstType = CGF.getContext().getCanonicalType(DstType); 450 if (SrcType == DstType) return Src; 451 452 if (DstType->isVoidType()) return 0; 453 454 // Handle conversions to bool first, they are special: comparisons against 0. 455 if (DstType->isBooleanType()) 456 return EmitConversionToBool(Src, SrcType); 457 458 const llvm::Type *DstTy = ConvertType(DstType); 459 460 // Ignore conversions like int -> uint. 461 if (Src->getType() == DstTy) 462 return Src; 463 464 // Handle pointer conversions next: pointers can only be converted to/from 465 // other pointers and integers. Check for pointer types in terms of LLVM, as 466 // some native types (like Obj-C id) may map to a pointer type. 467 if (isa<llvm::PointerType>(DstTy)) { 468 // The source value may be an integer, or a pointer. 469 if (isa<llvm::PointerType>(Src->getType())) 470 return Builder.CreateBitCast(Src, DstTy, "conv"); 471 472 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 473 // First, convert to the correct width so that we control the kind of 474 // extension. 475 const llvm::Type *MiddleTy = CGF.IntPtrTy; 476 bool InputSigned = SrcType->isSignedIntegerType(); 477 llvm::Value* IntResult = 478 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 479 // Then, cast to pointer. 480 return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); 481 } 482 483 if (isa<llvm::PointerType>(Src->getType())) { 484 // Must be an ptr to int cast. 485 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 486 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 487 } 488 489 // A scalar can be splatted to an extended vector of the same element type 490 if (DstType->isExtVectorType() && !SrcType->isVectorType()) { 491 // Cast the scalar to element type 492 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType(); 493 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 494 495 // Insert the element in element zero of an undef vector 496 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 497 llvm::Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, 0); 498 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 499 500 // Splat the element across to all elements 501 llvm::SmallVector<llvm::Constant*, 16> Args; 502 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 503 for (unsigned i = 0; i < NumElements; i++) 504 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 0)); 505 506 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 507 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 508 return Yay; 509 } 510 511 // Allow bitcast from vector to integer/fp of the same size. 512 if (isa<llvm::VectorType>(Src->getType()) || 513 isa<llvm::VectorType>(DstTy)) 514 return Builder.CreateBitCast(Src, DstTy, "conv"); 515 516 // Finally, we have the arithmetic types: real int/float. 517 if (isa<llvm::IntegerType>(Src->getType())) { 518 bool InputSigned = SrcType->isSignedIntegerType(); 519 if (isa<llvm::IntegerType>(DstTy)) 520 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 521 else if (InputSigned) 522 return Builder.CreateSIToFP(Src, DstTy, "conv"); 523 else 524 return Builder.CreateUIToFP(Src, DstTy, "conv"); 525 } 526 527 assert(Src->getType()->isFloatingPointTy() && "Unknown real conversion"); 528 if (isa<llvm::IntegerType>(DstTy)) { 529 if (DstType->isSignedIntegerType()) 530 return Builder.CreateFPToSI(Src, DstTy, "conv"); 531 else 532 return Builder.CreateFPToUI(Src, DstTy, "conv"); 533 } 534 535 assert(DstTy->isFloatingPointTy() && "Unknown real conversion"); 536 if (DstTy->getTypeID() < Src->getType()->getTypeID()) 537 return Builder.CreateFPTrunc(Src, DstTy, "conv"); 538 else 539 return Builder.CreateFPExt(Src, DstTy, "conv"); 540} 541 542/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 543/// type to the specified destination type, where the destination type is an 544/// LLVM scalar type. 545Value *ScalarExprEmitter:: 546EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 547 QualType SrcTy, QualType DstTy) { 548 // Get the source element type. 549 SrcTy = SrcTy->getAs<ComplexType>()->getElementType(); 550 551 // Handle conversions to bool first, they are special: comparisons against 0. 552 if (DstTy->isBooleanType()) { 553 // Complex != 0 -> (Real != 0) | (Imag != 0) 554 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 555 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 556 return Builder.CreateOr(Src.first, Src.second, "tobool"); 557 } 558 559 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 560 // the imaginary part of the complex value is discarded and the value of the 561 // real part is converted according to the conversion rules for the 562 // corresponding real type. 563 return EmitScalarConversion(Src.first, SrcTy, DstTy); 564} 565 566Value *ScalarExprEmitter::EmitNullValue(QualType Ty) { 567 if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>()) 568 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 569 570 return llvm::Constant::getNullValue(ConvertType(Ty)); 571} 572 573//===----------------------------------------------------------------------===// 574// Visitor Methods 575//===----------------------------------------------------------------------===// 576 577Value *ScalarExprEmitter::VisitExpr(Expr *E) { 578 CGF.ErrorUnsupported(E, "scalar expression"); 579 if (E->getType()->isVoidType()) 580 return 0; 581 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 582} 583 584Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 585 // Vector Mask Case 586 if (E->getNumSubExprs() == 2 || 587 (E->getNumSubExprs() == 3 && E->getExpr(2)->getType()->isVectorType())) { 588 Value *LHS = CGF.EmitScalarExpr(E->getExpr(0)); 589 Value *RHS = CGF.EmitScalarExpr(E->getExpr(1)); 590 Value *Mask; 591 592 const llvm::VectorType *LTy = cast<llvm::VectorType>(LHS->getType()); 593 unsigned LHSElts = LTy->getNumElements(); 594 595 if (E->getNumSubExprs() == 3) { 596 Mask = CGF.EmitScalarExpr(E->getExpr(2)); 597 598 // Shuffle LHS & RHS into one input vector. 599 llvm::SmallVector<llvm::Constant*, 32> concat; 600 for (unsigned i = 0; i != LHSElts; ++i) { 601 concat.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 2*i)); 602 concat.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 2*i+1)); 603 } 604 605 Value* CV = llvm::ConstantVector::get(concat.begin(), concat.size()); 606 LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat"); 607 LHSElts *= 2; 608 } else { 609 Mask = RHS; 610 } 611 612 const llvm::VectorType *MTy = cast<llvm::VectorType>(Mask->getType()); 613 llvm::Constant* EltMask; 614 615 // Treat vec3 like vec4. 616 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) 617 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 618 (1 << llvm::Log2_32(LHSElts+2))-1); 619 else if ((LHSElts == 3) && (E->getNumSubExprs() == 2)) 620 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 621 (1 << llvm::Log2_32(LHSElts+1))-1); 622 else 623 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 624 (1 << llvm::Log2_32(LHSElts))-1); 625 626 // Mask off the high bits of each shuffle index. 627 llvm::SmallVector<llvm::Constant *, 32> MaskV; 628 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) 629 MaskV.push_back(EltMask); 630 631 Value* MaskBits = llvm::ConstantVector::get(MaskV.begin(), MaskV.size()); 632 Mask = Builder.CreateAnd(Mask, MaskBits, "mask"); 633 634 // newv = undef 635 // mask = mask & maskbits 636 // for each elt 637 // n = extract mask i 638 // x = extract val n 639 // newv = insert newv, x, i 640 const llvm::VectorType *RTy = llvm::VectorType::get(LTy->getElementType(), 641 MTy->getNumElements()); 642 Value* NewV = llvm::UndefValue::get(RTy); 643 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) { 644 Value *Indx = llvm::ConstantInt::get(CGF.Int32Ty, i); 645 Indx = Builder.CreateExtractElement(Mask, Indx, "shuf_idx"); 646 Indx = Builder.CreateZExt(Indx, CGF.Int32Ty, "idx_zext"); 647 648 // Handle vec3 special since the index will be off by one for the RHS. 649 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) { 650 Value *cmpIndx, *newIndx; 651 cmpIndx = Builder.CreateICmpUGT(Indx, 652 llvm::ConstantInt::get(CGF.Int32Ty, 3), 653 "cmp_shuf_idx"); 654 newIndx = Builder.CreateSub(Indx, llvm::ConstantInt::get(CGF.Int32Ty,1), 655 "shuf_idx_adj"); 656 Indx = Builder.CreateSelect(cmpIndx, newIndx, Indx, "sel_shuf_idx"); 657 } 658 Value *VExt = Builder.CreateExtractElement(LHS, Indx, "shuf_elt"); 659 NewV = Builder.CreateInsertElement(NewV, VExt, Indx, "shuf_ins"); 660 } 661 return NewV; 662 } 663 664 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 665 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 666 667 // Handle vec3 special since the index will be off by one for the RHS. 668 llvm::SmallVector<llvm::Constant*, 32> indices; 669 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 670 llvm::Constant *C = cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i))); 671 const llvm::VectorType *VTy = cast<llvm::VectorType>(V1->getType()); 672 if (VTy->getNumElements() == 3) { 673 if (llvm::ConstantInt *CI = dyn_cast<llvm::ConstantInt>(C)) { 674 uint64_t cVal = CI->getZExtValue(); 675 if (cVal > 3) { 676 C = llvm::ConstantInt::get(C->getType(), cVal-1); 677 } 678 } 679 } 680 indices.push_back(C); 681 } 682 683 Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); 684 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 685} 686Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { 687 Expr::EvalResult Result; 688 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 689 if (E->isArrow()) 690 CGF.EmitScalarExpr(E->getBase()); 691 else 692 EmitLValue(E->getBase()); 693 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 694 } 695 return EmitLoadOfLValue(E); 696} 697 698Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 699 TestAndClearIgnoreResultAssign(); 700 701 // Emit subscript expressions in rvalue context's. For most cases, this just 702 // loads the lvalue formed by the subscript expr. However, we have to be 703 // careful, because the base of a vector subscript is occasionally an rvalue, 704 // so we can't get it as an lvalue. 705 if (!E->getBase()->getType()->isVectorType()) 706 return EmitLoadOfLValue(E); 707 708 // Handle the vector case. The base must be a vector, the index must be an 709 // integer value. 710 Value *Base = Visit(E->getBase()); 711 Value *Idx = Visit(E->getIdx()); 712 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerType(); 713 Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vecidxcast"); 714 return Builder.CreateExtractElement(Base, Idx, "vecext"); 715} 716 717static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, 718 unsigned Off, const llvm::Type *I32Ty) { 719 int MV = SVI->getMaskValue(Idx); 720 if (MV == -1) 721 return llvm::UndefValue::get(I32Ty); 722 return llvm::ConstantInt::get(I32Ty, Off+MV); 723} 724 725Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) { 726 bool Ignore = TestAndClearIgnoreResultAssign(); 727 (void)Ignore; 728 assert (Ignore == false && "init list ignored"); 729 unsigned NumInitElements = E->getNumInits(); 730 731 if (E->hadArrayRangeDesignator()) 732 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 733 734 const llvm::VectorType *VType = 735 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 736 737 // We have a scalar in braces. Just use the first element. 738 if (!VType) 739 return Visit(E->getInit(0)); 740 741 unsigned ResElts = VType->getNumElements(); 742 743 // Loop over initializers collecting the Value for each, and remembering 744 // whether the source was swizzle (ExtVectorElementExpr). This will allow 745 // us to fold the shuffle for the swizzle into the shuffle for the vector 746 // initializer, since LLVM optimizers generally do not want to touch 747 // shuffles. 748 unsigned CurIdx = 0; 749 bool VIsUndefShuffle = false; 750 llvm::Value *V = llvm::UndefValue::get(VType); 751 for (unsigned i = 0; i != NumInitElements; ++i) { 752 Expr *IE = E->getInit(i); 753 Value *Init = Visit(IE); 754 llvm::SmallVector<llvm::Constant*, 16> Args; 755 756 const llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType()); 757 758 // Handle scalar elements. If the scalar initializer is actually one 759 // element of a different vector of the same width, use shuffle instead of 760 // extract+insert. 761 if (!VVT) { 762 if (isa<ExtVectorElementExpr>(IE)) { 763 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init); 764 765 if (EI->getVectorOperandType()->getNumElements() == ResElts) { 766 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand()); 767 Value *LHS = 0, *RHS = 0; 768 if (CurIdx == 0) { 769 // insert into undef -> shuffle (src, undef) 770 Args.push_back(C); 771 for (unsigned j = 1; j != ResElts; ++j) 772 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 773 774 LHS = EI->getVectorOperand(); 775 RHS = V; 776 VIsUndefShuffle = true; 777 } else if (VIsUndefShuffle) { 778 // insert into undefshuffle && size match -> shuffle (v, src) 779 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V); 780 for (unsigned j = 0; j != CurIdx; ++j) 781 Args.push_back(getMaskElt(SVV, j, 0, CGF.Int32Ty)); 782 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 783 ResElts + C->getZExtValue())); 784 for (unsigned j = CurIdx + 1; j != ResElts; ++j) 785 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 786 787 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 788 RHS = EI->getVectorOperand(); 789 VIsUndefShuffle = false; 790 } 791 if (!Args.empty()) { 792 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 793 V = Builder.CreateShuffleVector(LHS, RHS, Mask); 794 ++CurIdx; 795 continue; 796 } 797 } 798 } 799 Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, CurIdx); 800 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 801 VIsUndefShuffle = false; 802 ++CurIdx; 803 continue; 804 } 805 806 unsigned InitElts = VVT->getNumElements(); 807 808 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's 809 // input is the same width as the vector being constructed, generate an 810 // optimized shuffle of the swizzle input into the result. 811 unsigned Offset = (CurIdx == 0) ? 0 : ResElts; 812 if (isa<ExtVectorElementExpr>(IE)) { 813 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init); 814 Value *SVOp = SVI->getOperand(0); 815 const llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType()); 816 817 if (OpTy->getNumElements() == ResElts) { 818 for (unsigned j = 0; j != CurIdx; ++j) { 819 // If the current vector initializer is a shuffle with undef, merge 820 // this shuffle directly into it. 821 if (VIsUndefShuffle) { 822 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0, 823 CGF.Int32Ty)); 824 } else { 825 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); 826 } 827 } 828 for (unsigned j = 0, je = InitElts; j != je; ++j) 829 Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty)); 830 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 831 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 832 833 if (VIsUndefShuffle) 834 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 835 836 Init = SVOp; 837 } 838 } 839 840 // Extend init to result vector length, and then shuffle its contribution 841 // to the vector initializer into V. 842 if (Args.empty()) { 843 for (unsigned j = 0; j != InitElts; ++j) 844 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); 845 for (unsigned j = InitElts; j != ResElts; ++j) 846 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 847 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 848 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), 849 Mask, "vext"); 850 851 Args.clear(); 852 for (unsigned j = 0; j != CurIdx; ++j) 853 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); 854 for (unsigned j = 0; j != InitElts; ++j) 855 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j+Offset)); 856 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 857 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 858 } 859 860 // If V is undef, make sure it ends up on the RHS of the shuffle to aid 861 // merging subsequent shuffles into this one. 862 if (CurIdx == 0) 863 std::swap(V, Init); 864 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 865 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); 866 VIsUndefShuffle = isa<llvm::UndefValue>(Init); 867 CurIdx += InitElts; 868 } 869 870 // FIXME: evaluate codegen vs. shuffling against constant null vector. 871 // Emit remaining default initializers. 872 const llvm::Type *EltTy = VType->getElementType(); 873 874 // Emit remaining default initializers 875 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { 876 Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, CurIdx); 877 llvm::Value *Init = llvm::Constant::getNullValue(EltTy); 878 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 879 } 880 return V; 881} 882 883static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { 884 const Expr *E = CE->getSubExpr(); 885 886 if (CE->getCastKind() == CastExpr::CK_UncheckedDerivedToBase) 887 return false; 888 889 if (isa<CXXThisExpr>(E)) { 890 // We always assume that 'this' is never null. 891 return false; 892 } 893 894 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { 895 // And that glvalue casts are never null. 896 if (ICE->getCategory() != ImplicitCastExpr::RValue) 897 return false; 898 } 899 900 return true; 901} 902 903// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 904// have to handle a more broad range of conversions than explicit casts, as they 905// handle things like function to ptr-to-function decay etc. 906Value *ScalarExprEmitter::EmitCastExpr(CastExpr *CE) { 907 Expr *E = CE->getSubExpr(); 908 QualType DestTy = CE->getType(); 909 CastExpr::CastKind Kind = CE->getCastKind(); 910 911 if (!DestTy->isVoidType()) 912 TestAndClearIgnoreResultAssign(); 913 914 // Since almost all cast kinds apply to scalars, this switch doesn't have 915 // a default case, so the compiler will warn on a missing case. The cases 916 // are in the same order as in the CastKind enum. 917 switch (Kind) { 918 case CastExpr::CK_Unknown: 919 // FIXME: All casts should have a known kind! 920 //assert(0 && "Unknown cast kind!"); 921 break; 922 923 case CastExpr::CK_LValueBitCast: 924 case CastExpr::CK_ObjCObjectLValueCast: { 925 Value *V = EmitLValue(E).getAddress(); 926 V = Builder.CreateBitCast(V, 927 ConvertType(CGF.getContext().getPointerType(DestTy))); 928 return EmitLoadOfLValue(CGF.MakeAddrLValue(V, DestTy), DestTy); 929 } 930 931 case CastExpr::CK_AnyPointerToObjCPointerCast: 932 case CastExpr::CK_AnyPointerToBlockPointerCast: 933 case CastExpr::CK_BitCast: { 934 Value *Src = Visit(const_cast<Expr*>(E)); 935 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 936 } 937 case CastExpr::CK_NoOp: 938 case CastExpr::CK_UserDefinedConversion: 939 return Visit(const_cast<Expr*>(E)); 940 941 case CastExpr::CK_BaseToDerived: { 942 const CXXRecordDecl *DerivedClassDecl = 943 DestTy->getCXXRecordDeclForPointerType(); 944 945 return CGF.GetAddressOfDerivedClass(Visit(E), DerivedClassDecl, 946 CE->path_begin(), CE->path_end(), 947 ShouldNullCheckClassCastValue(CE)); 948 } 949 case CastExpr::CK_UncheckedDerivedToBase: 950 case CastExpr::CK_DerivedToBase: { 951 const RecordType *DerivedClassTy = 952 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 953 CXXRecordDecl *DerivedClassDecl = 954 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 955 956 return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl, 957 CE->path_begin(), CE->path_end(), 958 ShouldNullCheckClassCastValue(CE)); 959 } 960 case CastExpr::CK_Dynamic: { 961 Value *V = Visit(const_cast<Expr*>(E)); 962 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 963 return CGF.EmitDynamicCast(V, DCE); 964 } 965 case CastExpr::CK_ToUnion: 966 assert(0 && "Should be unreachable!"); 967 break; 968 969 case CastExpr::CK_ArrayToPointerDecay: { 970 assert(E->getType()->isArrayType() && 971 "Array to pointer decay must have array source type!"); 972 973 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 974 975 // Note that VLA pointers are always decayed, so we don't need to do 976 // anything here. 977 if (!E->getType()->isVariableArrayType()) { 978 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 979 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 980 ->getElementType()) && 981 "Expected pointer to array"); 982 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 983 } 984 985 return V; 986 } 987 case CastExpr::CK_FunctionToPointerDecay: 988 return EmitLValue(E).getAddress(); 989 990 case CastExpr::CK_NullToMemberPointer: { 991 // If the subexpression's type is the C++0x nullptr_t, emit the 992 // subexpression, which may have side effects. 993 if (E->getType()->isNullPtrType()) 994 (void) Visit(E); 995 996 const MemberPointerType *MPT = CE->getType()->getAs<MemberPointerType>(); 997 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 998 } 999 1000 case CastExpr::CK_BaseToDerivedMemberPointer: 1001 case CastExpr::CK_DerivedToBaseMemberPointer: { 1002 Value *Src = Visit(E); 1003 1004 // Note that the AST doesn't distinguish between checked and 1005 // unchecked member pointer conversions, so we always have to 1006 // implement checked conversions here. This is inefficient when 1007 // actual control flow may be required in order to perform the 1008 // check, which it is for data member pointers (but not member 1009 // function pointers on Itanium and ARM). 1010 return CGF.CGM.getCXXABI().EmitMemberPointerConversion(CGF, CE, Src); 1011 } 1012 1013 1014 case CastExpr::CK_ConstructorConversion: 1015 assert(0 && "Should be unreachable!"); 1016 break; 1017 1018 case CastExpr::CK_IntegralToPointer: { 1019 Value *Src = Visit(const_cast<Expr*>(E)); 1020 1021 // First, convert to the correct width so that we control the kind of 1022 // extension. 1023 const llvm::Type *MiddleTy = CGF.IntPtrTy; 1024 bool InputSigned = E->getType()->isSignedIntegerType(); 1025 llvm::Value* IntResult = 1026 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 1027 1028 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 1029 } 1030 case CastExpr::CK_PointerToIntegral: { 1031 Value *Src = Visit(const_cast<Expr*>(E)); 1032 return Builder.CreatePtrToInt(Src, ConvertType(DestTy)); 1033 } 1034 case CastExpr::CK_ToVoid: { 1035 if (E->Classify(CGF.getContext()).isGLValue()) 1036 CGF.EmitLValue(E); 1037 else 1038 CGF.EmitAnyExpr(E, 0, false, true); 1039 return 0; 1040 } 1041 case CastExpr::CK_VectorSplat: { 1042 const llvm::Type *DstTy = ConvertType(DestTy); 1043 Value *Elt = Visit(const_cast<Expr*>(E)); 1044 1045 // Insert the element in element zero of an undef vector 1046 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 1047 llvm::Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, 0); 1048 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 1049 1050 // Splat the element across to all elements 1051 llvm::SmallVector<llvm::Constant*, 16> Args; 1052 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 1053 for (unsigned i = 0; i < NumElements; i++) 1054 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 0)); 1055 1056 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 1057 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 1058 return Yay; 1059 } 1060 case CastExpr::CK_IntegralCast: 1061 case CastExpr::CK_IntegralToFloating: 1062 case CastExpr::CK_FloatingToIntegral: 1063 case CastExpr::CK_FloatingCast: 1064 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 1065 1066 case CastExpr::CK_MemberPointerToBoolean: { 1067 llvm::Value *MemPtr = Visit(E); 1068 const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>(); 1069 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT); 1070 } 1071 } 1072 1073 // Handle cases where the source is an non-complex type. 1074 1075 if (!CGF.hasAggregateLLVMType(E->getType())) { 1076 Value *Src = Visit(const_cast<Expr*>(E)); 1077 1078 // Use EmitScalarConversion to perform the conversion. 1079 return EmitScalarConversion(Src, E->getType(), DestTy); 1080 } 1081 1082 if (E->getType()->isAnyComplexType()) { 1083 // Handle cases where the source is a complex type. 1084 bool IgnoreImag = true; 1085 bool IgnoreImagAssign = true; 1086 bool IgnoreReal = IgnoreResultAssign; 1087 bool IgnoreRealAssign = IgnoreResultAssign; 1088 if (DestTy->isBooleanType()) 1089 IgnoreImagAssign = IgnoreImag = false; 1090 else if (DestTy->isVoidType()) { 1091 IgnoreReal = IgnoreImag = false; 1092 IgnoreRealAssign = IgnoreImagAssign = true; 1093 } 1094 CodeGenFunction::ComplexPairTy V 1095 = CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign, 1096 IgnoreImagAssign); 1097 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 1098 } 1099 1100 // Okay, this is a cast from an aggregate. It must be a cast to void. Just 1101 // evaluate the result and return. 1102 CGF.EmitAggExpr(E, 0, false, true); 1103 return 0; 1104} 1105 1106Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 1107 return CGF.EmitCompoundStmt(*E->getSubStmt(), 1108 !E->getType()->isVoidType()).getScalarVal(); 1109} 1110 1111Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 1112 llvm::Value *V = CGF.GetAddrOfBlockDecl(E); 1113 if (E->getType().isObjCGCWeak()) 1114 return CGF.CGM.getObjCRuntime().EmitObjCWeakRead(CGF, V); 1115 return Builder.CreateLoad(V, "tmp"); 1116} 1117 1118//===----------------------------------------------------------------------===// 1119// Unary Operators 1120//===----------------------------------------------------------------------===// 1121 1122llvm::Value *ScalarExprEmitter:: 1123EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 1124 bool isInc, bool isPre) { 1125 1126 QualType ValTy = E->getSubExpr()->getType(); 1127 llvm::Value *InVal = EmitLoadOfLValue(LV, ValTy); 1128 1129 int AmountVal = isInc ? 1 : -1; 1130 1131 if (ValTy->isPointerType() && 1132 ValTy->getAs<PointerType>()->isVariableArrayType()) { 1133 // The amount of the addition/subtraction needs to account for the VLA size 1134 CGF.ErrorUnsupported(E, "VLA pointer inc/dec"); 1135 } 1136 1137 llvm::Value *NextVal; 1138 if (const llvm::PointerType *PT = 1139 dyn_cast<llvm::PointerType>(InVal->getType())) { 1140 llvm::Constant *Inc = llvm::ConstantInt::get(CGF.Int32Ty, AmountVal); 1141 if (!isa<llvm::FunctionType>(PT->getElementType())) { 1142 QualType PTEE = ValTy->getPointeeType(); 1143 if (const ObjCObjectType *OIT = PTEE->getAs<ObjCObjectType>()) { 1144 // Handle interface types, which are not represented with a concrete 1145 // type. 1146 int size = CGF.getContext().getTypeSize(OIT) / 8; 1147 if (!isInc) 1148 size = -size; 1149 Inc = llvm::ConstantInt::get(Inc->getType(), size); 1150 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1151 InVal = Builder.CreateBitCast(InVal, i8Ty); 1152 NextVal = Builder.CreateGEP(InVal, Inc, "add.ptr"); 1153 llvm::Value *lhs = LV.getAddress(); 1154 lhs = Builder.CreateBitCast(lhs, llvm::PointerType::getUnqual(i8Ty)); 1155 LV = CGF.MakeAddrLValue(lhs, ValTy); 1156 } else 1157 NextVal = Builder.CreateInBoundsGEP(InVal, Inc, "ptrincdec"); 1158 } else { 1159 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1160 NextVal = Builder.CreateBitCast(InVal, i8Ty, "tmp"); 1161 NextVal = Builder.CreateGEP(NextVal, Inc, "ptrincdec"); 1162 NextVal = Builder.CreateBitCast(NextVal, InVal->getType()); 1163 } 1164 } else if (InVal->getType()->isIntegerTy(1) && isInc) { 1165 // Bool++ is an interesting case, due to promotion rules, we get: 1166 // Bool++ -> Bool = Bool+1 -> Bool = (int)Bool+1 -> 1167 // Bool = ((int)Bool+1) != 0 1168 // An interesting aspect of this is that increment is always true. 1169 // Decrement does not have this property. 1170 NextVal = llvm::ConstantInt::getTrue(VMContext); 1171 } else if (isa<llvm::IntegerType>(InVal->getType())) { 1172 NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); 1173 1174 if (!ValTy->isSignedIntegerType()) 1175 // Unsigned integer inc is always two's complement. 1176 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1177 else { 1178 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1179 case LangOptions::SOB_Undefined: 1180 NextVal = Builder.CreateNSWAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1181 break; 1182 case LangOptions::SOB_Defined: 1183 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1184 break; 1185 case LangOptions::SOB_Trapping: 1186 BinOpInfo BinOp; 1187 BinOp.LHS = InVal; 1188 BinOp.RHS = NextVal; 1189 BinOp.Ty = E->getType(); 1190 BinOp.Opcode = BinaryOperator::Add; 1191 BinOp.E = E; 1192 NextVal = EmitOverflowCheckedBinOp(BinOp); 1193 break; 1194 } 1195 } 1196 } else { 1197 // Add the inc/dec to the real part. 1198 if (InVal->getType()->isFloatTy()) 1199 NextVal = 1200 llvm::ConstantFP::get(VMContext, 1201 llvm::APFloat(static_cast<float>(AmountVal))); 1202 else if (InVal->getType()->isDoubleTy()) 1203 NextVal = 1204 llvm::ConstantFP::get(VMContext, 1205 llvm::APFloat(static_cast<double>(AmountVal))); 1206 else { 1207 llvm::APFloat F(static_cast<float>(AmountVal)); 1208 bool ignored; 1209 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, 1210 &ignored); 1211 NextVal = llvm::ConstantFP::get(VMContext, F); 1212 } 1213 NextVal = Builder.CreateFAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1214 } 1215 1216 // Store the updated result through the lvalue. 1217 if (LV.isBitField()) 1218 CGF.EmitStoreThroughBitfieldLValue(RValue::get(NextVal), LV, ValTy, &NextVal); 1219 else 1220 CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV, ValTy); 1221 1222 // If this is a postinc, return the value read from memory, otherwise use the 1223 // updated value. 1224 return isPre ? NextVal : InVal; 1225} 1226 1227 1228 1229Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1230 TestAndClearIgnoreResultAssign(); 1231 // Emit unary minus with EmitSub so we handle overflow cases etc. 1232 BinOpInfo BinOp; 1233 BinOp.RHS = Visit(E->getSubExpr()); 1234 1235 if (BinOp.RHS->getType()->isFPOrFPVectorTy()) 1236 BinOp.LHS = llvm::ConstantFP::getZeroValueForNegation(BinOp.RHS->getType()); 1237 else 1238 BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType()); 1239 BinOp.Ty = E->getType(); 1240 BinOp.Opcode = BinaryOperator::Sub; 1241 BinOp.E = E; 1242 return EmitSub(BinOp); 1243} 1244 1245Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1246 TestAndClearIgnoreResultAssign(); 1247 Value *Op = Visit(E->getSubExpr()); 1248 return Builder.CreateNot(Op, "neg"); 1249} 1250 1251Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1252 // Compare operand to zero. 1253 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1254 1255 // Invert value. 1256 // TODO: Could dynamically modify easy computations here. For example, if 1257 // the operand is an icmp ne, turn into icmp eq. 1258 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1259 1260 // ZExt result to the expr type. 1261 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1262} 1263 1264Value *ScalarExprEmitter::VisitOffsetOfExpr(OffsetOfExpr *E) { 1265 // Try folding the offsetof to a constant. 1266 Expr::EvalResult EvalResult; 1267 if (E->Evaluate(EvalResult, CGF.getContext())) 1268 return llvm::ConstantInt::get(VMContext, EvalResult.Val.getInt()); 1269 1270 // Loop over the components of the offsetof to compute the value. 1271 unsigned n = E->getNumComponents(); 1272 const llvm::Type* ResultType = ConvertType(E->getType()); 1273 llvm::Value* Result = llvm::Constant::getNullValue(ResultType); 1274 QualType CurrentType = E->getTypeSourceInfo()->getType(); 1275 for (unsigned i = 0; i != n; ++i) { 1276 OffsetOfExpr::OffsetOfNode ON = E->getComponent(i); 1277 llvm::Value *Offset = 0; 1278 switch (ON.getKind()) { 1279 case OffsetOfExpr::OffsetOfNode::Array: { 1280 // Compute the index 1281 Expr *IdxExpr = E->getIndexExpr(ON.getArrayExprIndex()); 1282 llvm::Value* Idx = CGF.EmitScalarExpr(IdxExpr); 1283 bool IdxSigned = IdxExpr->getType()->isSignedIntegerType(); 1284 Idx = Builder.CreateIntCast(Idx, ResultType, IdxSigned, "conv"); 1285 1286 // Save the element type 1287 CurrentType = 1288 CGF.getContext().getAsArrayType(CurrentType)->getElementType(); 1289 1290 // Compute the element size 1291 llvm::Value* ElemSize = llvm::ConstantInt::get(ResultType, 1292 CGF.getContext().getTypeSizeInChars(CurrentType).getQuantity()); 1293 1294 // Multiply out to compute the result 1295 Offset = Builder.CreateMul(Idx, ElemSize); 1296 break; 1297 } 1298 1299 case OffsetOfExpr::OffsetOfNode::Field: { 1300 FieldDecl *MemberDecl = ON.getField(); 1301 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1302 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1303 1304 // Compute the index of the field in its parent. 1305 unsigned i = 0; 1306 // FIXME: It would be nice if we didn't have to loop here! 1307 for (RecordDecl::field_iterator Field = RD->field_begin(), 1308 FieldEnd = RD->field_end(); 1309 Field != FieldEnd; (void)++Field, ++i) { 1310 if (*Field == MemberDecl) 1311 break; 1312 } 1313 assert(i < RL.getFieldCount() && "offsetof field in wrong type"); 1314 1315 // Compute the offset to the field 1316 int64_t OffsetInt = RL.getFieldOffset(i) / 1317 CGF.getContext().getCharWidth(); 1318 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1319 1320 // Save the element type. 1321 CurrentType = MemberDecl->getType(); 1322 break; 1323 } 1324 1325 case OffsetOfExpr::OffsetOfNode::Identifier: 1326 llvm_unreachable("dependent __builtin_offsetof"); 1327 1328 case OffsetOfExpr::OffsetOfNode::Base: { 1329 if (ON.getBase()->isVirtual()) { 1330 CGF.ErrorUnsupported(E, "virtual base in offsetof"); 1331 continue; 1332 } 1333 1334 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1335 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1336 1337 // Save the element type. 1338 CurrentType = ON.getBase()->getType(); 1339 1340 // Compute the offset to the base. 1341 const RecordType *BaseRT = CurrentType->getAs<RecordType>(); 1342 CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl()); 1343 int64_t OffsetInt = RL.getBaseClassOffset(BaseRD) / 1344 CGF.getContext().getCharWidth(); 1345 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1346 break; 1347 } 1348 } 1349 Result = Builder.CreateAdd(Result, Offset); 1350 } 1351 return Result; 1352} 1353 1354/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of 1355/// argument of the sizeof expression as an integer. 1356Value * 1357ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { 1358 QualType TypeToSize = E->getTypeOfArgument(); 1359 if (E->isSizeOf()) { 1360 if (const VariableArrayType *VAT = 1361 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1362 if (E->isArgumentType()) { 1363 // sizeof(type) - make sure to emit the VLA size. 1364 CGF.EmitVLASize(TypeToSize); 1365 } else { 1366 // C99 6.5.3.4p2: If the argument is an expression of type 1367 // VLA, it is evaluated. 1368 CGF.EmitAnyExpr(E->getArgumentExpr()); 1369 } 1370 1371 return CGF.GetVLASize(VAT); 1372 } 1373 } 1374 1375 // If this isn't sizeof(vla), the result must be constant; use the constant 1376 // folding logic so we don't have to duplicate it here. 1377 Expr::EvalResult Result; 1378 E->Evaluate(Result, CGF.getContext()); 1379 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 1380} 1381 1382Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1383 Expr *Op = E->getSubExpr(); 1384 if (Op->getType()->isAnyComplexType()) 1385 return CGF.EmitComplexExpr(Op, false, true, false, true).first; 1386 return Visit(Op); 1387} 1388Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1389 Expr *Op = E->getSubExpr(); 1390 if (Op->getType()->isAnyComplexType()) 1391 return CGF.EmitComplexExpr(Op, true, false, true, false).second; 1392 1393 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1394 // effects are evaluated, but not the actual value. 1395 if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) 1396 CGF.EmitLValue(Op); 1397 else 1398 CGF.EmitScalarExpr(Op, true); 1399 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1400} 1401 1402//===----------------------------------------------------------------------===// 1403// Binary Operators 1404//===----------------------------------------------------------------------===// 1405 1406BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1407 TestAndClearIgnoreResultAssign(); 1408 BinOpInfo Result; 1409 Result.LHS = Visit(E->getLHS()); 1410 Result.RHS = Visit(E->getRHS()); 1411 Result.Ty = E->getType(); 1412 Result.Opcode = E->getOpcode(); 1413 Result.E = E; 1414 return Result; 1415} 1416 1417LValue ScalarExprEmitter::EmitCompoundAssignLValue( 1418 const CompoundAssignOperator *E, 1419 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &), 1420 Value *&Result) { 1421 QualType LHSTy = E->getLHS()->getType(); 1422 BinOpInfo OpInfo; 1423 1424 if (E->getComputationResultType()->isAnyComplexType()) { 1425 // This needs to go through the complex expression emitter, but it's a tad 1426 // complicated to do that... I'm leaving it out for now. (Note that we do 1427 // actually need the imaginary part of the RHS for multiplication and 1428 // division.) 1429 CGF.ErrorUnsupported(E, "complex compound assignment"); 1430 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType())); 1431 return LValue(); 1432 } 1433 1434 // Emit the RHS first. __block variables need to have the rhs evaluated 1435 // first, plus this should improve codegen a little. 1436 OpInfo.RHS = Visit(E->getRHS()); 1437 OpInfo.Ty = E->getComputationResultType(); 1438 OpInfo.Opcode = E->getOpcode(); 1439 OpInfo.E = E; 1440 // Load/convert the LHS. 1441 LValue LHSLV = EmitCheckedLValue(E->getLHS()); 1442 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 1443 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 1444 E->getComputationLHSType()); 1445 1446 // Expand the binary operator. 1447 Result = (this->*Func)(OpInfo); 1448 1449 // Convert the result back to the LHS type. 1450 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 1451 1452 // Store the result value into the LHS lvalue. Bit-fields are handled 1453 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 1454 // 'An assignment expression has the value of the left operand after the 1455 // assignment...'. 1456 if (LHSLV.isBitField()) 1457 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, 1458 &Result); 1459 else 1460 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); 1461 1462 return LHSLV; 1463} 1464 1465Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 1466 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 1467 bool Ignore = TestAndClearIgnoreResultAssign(); 1468 Value *RHS; 1469 LValue LHS = EmitCompoundAssignLValue(E, Func, RHS); 1470 1471 // If the result is clearly ignored, return now. 1472 if (Ignore) 1473 return 0; 1474 1475 // Objective-C property assignment never reloads the value following a store. 1476 if (LHS.isPropertyRef() || LHS.isKVCRef()) 1477 return RHS; 1478 1479 // If the lvalue is non-volatile, return the computed value of the assignment. 1480 if (!LHS.isVolatileQualified()) 1481 return RHS; 1482 1483 // Otherwise, reload the value. 1484 return EmitLoadOfLValue(LHS, E->getType()); 1485} 1486 1487 1488Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 1489 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1490 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 1491 else if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1492 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 1493 else 1494 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 1495} 1496 1497Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 1498 // Rem in C can't be a floating point type: C99 6.5.5p2. 1499 if (Ops.Ty->isUnsignedIntegerType()) 1500 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 1501 else 1502 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 1503} 1504 1505Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 1506 unsigned IID; 1507 unsigned OpID = 0; 1508 1509 switch (Ops.Opcode) { 1510 case BinaryOperator::Add: 1511 case BinaryOperator::AddAssign: 1512 OpID = 1; 1513 IID = llvm::Intrinsic::sadd_with_overflow; 1514 break; 1515 case BinaryOperator::Sub: 1516 case BinaryOperator::SubAssign: 1517 OpID = 2; 1518 IID = llvm::Intrinsic::ssub_with_overflow; 1519 break; 1520 case BinaryOperator::Mul: 1521 case BinaryOperator::MulAssign: 1522 OpID = 3; 1523 IID = llvm::Intrinsic::smul_with_overflow; 1524 break; 1525 default: 1526 assert(false && "Unsupported operation for overflow detection"); 1527 IID = 0; 1528 } 1529 OpID <<= 1; 1530 OpID |= 1; 1531 1532 const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1533 1534 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1); 1535 1536 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1537 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1538 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1539 1540 // Branch in case of overflow. 1541 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); 1542 llvm::BasicBlock *continueBB = CGF.createBasicBlock("nooverflow", CGF.CurFn); 1543 1544 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1545 1546 // Handle overflow with llvm.trap. 1547 // TODO: it would be better to generate one of these blocks per function. 1548 Builder.SetInsertPoint(overflowBB); 1549 llvm::Function *Trap = CGF.CGM.getIntrinsic(llvm::Intrinsic::trap); 1550 Builder.CreateCall(Trap); 1551 Builder.CreateUnreachable(); 1552 1553 // Continue on. 1554 Builder.SetInsertPoint(continueBB); 1555 return result; 1556} 1557 1558Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 1559 if (!Ops.Ty->isAnyPointerType()) { 1560 if (Ops.Ty->hasSignedIntegerRepresentation()) { 1561 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1562 case LangOptions::SOB_Undefined: 1563 return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add"); 1564 case LangOptions::SOB_Defined: 1565 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1566 case LangOptions::SOB_Trapping: 1567 return EmitOverflowCheckedBinOp(Ops); 1568 } 1569 } 1570 1571 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1572 return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add"); 1573 1574 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1575 } 1576 1577 // Must have binary (not unary) expr here. Unary pointer decrement doesn't 1578 // use this path. 1579 const BinaryOperator *BinOp = cast<BinaryOperator>(Ops.E); 1580 1581 if (Ops.Ty->isPointerType() && 1582 Ops.Ty->getAs<PointerType>()->isVariableArrayType()) { 1583 // The amount of the addition needs to account for the VLA size 1584 CGF.ErrorUnsupported(BinOp, "VLA pointer addition"); 1585 } 1586 1587 Value *Ptr, *Idx; 1588 Expr *IdxExp; 1589 const PointerType *PT = BinOp->getLHS()->getType()->getAs<PointerType>(); 1590 const ObjCObjectPointerType *OPT = 1591 BinOp->getLHS()->getType()->getAs<ObjCObjectPointerType>(); 1592 if (PT || OPT) { 1593 Ptr = Ops.LHS; 1594 Idx = Ops.RHS; 1595 IdxExp = BinOp->getRHS(); 1596 } else { // int + pointer 1597 PT = BinOp->getRHS()->getType()->getAs<PointerType>(); 1598 OPT = BinOp->getRHS()->getType()->getAs<ObjCObjectPointerType>(); 1599 assert((PT || OPT) && "Invalid add expr"); 1600 Ptr = Ops.RHS; 1601 Idx = Ops.LHS; 1602 IdxExp = BinOp->getLHS(); 1603 } 1604 1605 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1606 if (Width < CGF.LLVMPointerWidth) { 1607 // Zero or sign extend the pointer value based on whether the index is 1608 // signed or not. 1609 const llvm::Type *IdxType = CGF.IntPtrTy; 1610 if (IdxExp->getType()->isSignedIntegerType()) 1611 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1612 else 1613 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1614 } 1615 const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType(); 1616 // Handle interface types, which are not represented with a concrete type. 1617 if (const ObjCObjectType *OIT = ElementType->getAs<ObjCObjectType>()) { 1618 llvm::Value *InterfaceSize = 1619 llvm::ConstantInt::get(Idx->getType(), 1620 CGF.getContext().getTypeSizeInChars(OIT).getQuantity()); 1621 Idx = Builder.CreateMul(Idx, InterfaceSize); 1622 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1623 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1624 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1625 return Builder.CreateBitCast(Res, Ptr->getType()); 1626 } 1627 1628 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 1629 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 1630 // future proof. 1631 if (ElementType->isVoidType() || ElementType->isFunctionType()) { 1632 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1633 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1634 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1635 return Builder.CreateBitCast(Res, Ptr->getType()); 1636 } 1637 1638 return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr"); 1639} 1640 1641Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 1642 if (!isa<llvm::PointerType>(Ops.LHS->getType())) { 1643 if (Ops.Ty->hasSignedIntegerRepresentation()) { 1644 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1645 case LangOptions::SOB_Undefined: 1646 return Builder.CreateNSWSub(Ops.LHS, Ops.RHS, "sub"); 1647 case LangOptions::SOB_Defined: 1648 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1649 case LangOptions::SOB_Trapping: 1650 return EmitOverflowCheckedBinOp(Ops); 1651 } 1652 } 1653 1654 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1655 return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub"); 1656 1657 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1658 } 1659 1660 // Must have binary (not unary) expr here. Unary pointer increment doesn't 1661 // use this path. 1662 const BinaryOperator *BinOp = cast<BinaryOperator>(Ops.E); 1663 1664 if (BinOp->getLHS()->getType()->isPointerType() && 1665 BinOp->getLHS()->getType()->getAs<PointerType>()->isVariableArrayType()) { 1666 // The amount of the addition needs to account for the VLA size for 1667 // ptr-int 1668 // The amount of the division needs to account for the VLA size for 1669 // ptr-ptr. 1670 CGF.ErrorUnsupported(BinOp, "VLA pointer subtraction"); 1671 } 1672 1673 const QualType LHSType = BinOp->getLHS()->getType(); 1674 const QualType LHSElementType = LHSType->getPointeeType(); 1675 if (!isa<llvm::PointerType>(Ops.RHS->getType())) { 1676 // pointer - int 1677 Value *Idx = Ops.RHS; 1678 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1679 if (Width < CGF.LLVMPointerWidth) { 1680 // Zero or sign extend the pointer value based on whether the index is 1681 // signed or not. 1682 const llvm::Type *IdxType = CGF.IntPtrTy; 1683 if (BinOp->getRHS()->getType()->isSignedIntegerType()) 1684 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1685 else 1686 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1687 } 1688 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); 1689 1690 // Handle interface types, which are not represented with a concrete type. 1691 if (const ObjCObjectType *OIT = LHSElementType->getAs<ObjCObjectType>()) { 1692 llvm::Value *InterfaceSize = 1693 llvm::ConstantInt::get(Idx->getType(), 1694 CGF.getContext(). 1695 getTypeSizeInChars(OIT).getQuantity()); 1696 Idx = Builder.CreateMul(Idx, InterfaceSize); 1697 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1698 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1699 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr"); 1700 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1701 } 1702 1703 // Explicitly handle GNU void* and function pointer arithmetic 1704 // extensions. The GNU void* casts amount to no-ops since our void* type is 1705 // i8*, but this is future proof. 1706 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1707 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1708 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1709 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); 1710 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1711 } 1712 1713 return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr"); 1714 } else { 1715 // pointer - pointer 1716 Value *LHS = Ops.LHS; 1717 Value *RHS = Ops.RHS; 1718 1719 CharUnits ElementSize; 1720 1721 // Handle GCC extension for pointer arithmetic on void* and function pointer 1722 // types. 1723 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1724 ElementSize = CharUnits::One(); 1725 } else { 1726 ElementSize = CGF.getContext().getTypeSizeInChars(LHSElementType); 1727 } 1728 1729 const llvm::Type *ResultType = ConvertType(Ops.Ty); 1730 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 1731 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 1732 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 1733 1734 // Optimize out the shift for element size of 1. 1735 if (ElementSize.isOne()) 1736 return BytesBetween; 1737 1738 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 1739 // pointer difference in C is only defined in the case where both operands 1740 // are pointing to elements of an array. 1741 Value *BytesPerElt = 1742 llvm::ConstantInt::get(ResultType, ElementSize.getQuantity()); 1743 return Builder.CreateExactSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 1744 } 1745} 1746 1747Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 1748 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1749 // RHS to the same size as the LHS. 1750 Value *RHS = Ops.RHS; 1751 if (Ops.LHS->getType() != RHS->getType()) 1752 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1753 1754 if (CGF.CatchUndefined 1755 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1756 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1757 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1758 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1759 llvm::ConstantInt::get(RHS->getType(), Width)), 1760 Cont, CGF.getTrapBB()); 1761 CGF.EmitBlock(Cont); 1762 } 1763 1764 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 1765} 1766 1767Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 1768 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1769 // RHS to the same size as the LHS. 1770 Value *RHS = Ops.RHS; 1771 if (Ops.LHS->getType() != RHS->getType()) 1772 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1773 1774 if (CGF.CatchUndefined 1775 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1776 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1777 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1778 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1779 llvm::ConstantInt::get(RHS->getType(), Width)), 1780 Cont, CGF.getTrapBB()); 1781 CGF.EmitBlock(Cont); 1782 } 1783 1784 if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1785 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 1786 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 1787} 1788 1789Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 1790 unsigned SICmpOpc, unsigned FCmpOpc) { 1791 TestAndClearIgnoreResultAssign(); 1792 Value *Result; 1793 QualType LHSTy = E->getLHS()->getType(); 1794 if (const MemberPointerType *MPT = LHSTy->getAs<MemberPointerType>()) { 1795 assert(E->getOpcode() == BinaryOperator::EQ || 1796 E->getOpcode() == BinaryOperator::NE); 1797 Value *LHS = CGF.EmitScalarExpr(E->getLHS()); 1798 Value *RHS = CGF.EmitScalarExpr(E->getRHS()); 1799 Result = CGF.CGM.getCXXABI().EmitMemberPointerComparison( 1800 CGF, LHS, RHS, MPT, E->getOpcode() == BinaryOperator::NE); 1801 } else if (!LHSTy->isAnyComplexType()) { 1802 Value *LHS = Visit(E->getLHS()); 1803 Value *RHS = Visit(E->getRHS()); 1804 1805 if (LHS->getType()->isFPOrFPVectorTy()) { 1806 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 1807 LHS, RHS, "cmp"); 1808 } else if (LHSTy->hasSignedIntegerRepresentation()) { 1809 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 1810 LHS, RHS, "cmp"); 1811 } else { 1812 // Unsigned integers and pointers. 1813 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1814 LHS, RHS, "cmp"); 1815 } 1816 1817 // If this is a vector comparison, sign extend the result to the appropriate 1818 // vector integer type and return it (don't convert to bool). 1819 if (LHSTy->isVectorType()) 1820 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 1821 1822 } else { 1823 // Complex Comparison: can only be an equality comparison. 1824 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 1825 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 1826 1827 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 1828 1829 Value *ResultR, *ResultI; 1830 if (CETy->isRealFloatingType()) { 1831 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1832 LHS.first, RHS.first, "cmp.r"); 1833 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1834 LHS.second, RHS.second, "cmp.i"); 1835 } else { 1836 // Complex comparisons can only be equality comparisons. As such, signed 1837 // and unsigned opcodes are the same. 1838 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1839 LHS.first, RHS.first, "cmp.r"); 1840 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1841 LHS.second, RHS.second, "cmp.i"); 1842 } 1843 1844 if (E->getOpcode() == BinaryOperator::EQ) { 1845 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 1846 } else { 1847 assert(E->getOpcode() == BinaryOperator::NE && 1848 "Complex comparison other than == or != ?"); 1849 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 1850 } 1851 } 1852 1853 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 1854} 1855 1856Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 1857 bool Ignore = TestAndClearIgnoreResultAssign(); 1858 1859 // __block variables need to have the rhs evaluated first, plus this should 1860 // improve codegen just a little. 1861 Value *RHS = Visit(E->getRHS()); 1862 LValue LHS = EmitCheckedLValue(E->getLHS()); 1863 1864 // Store the value into the LHS. Bit-fields are handled specially 1865 // because the result is altered by the store, i.e., [C99 6.5.16p1] 1866 // 'An assignment expression has the value of the left operand after 1867 // the assignment...'. 1868 if (LHS.isBitField()) 1869 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), 1870 &RHS); 1871 else 1872 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 1873 1874 // If the result is clearly ignored, return now. 1875 if (Ignore) 1876 return 0; 1877 1878 // Objective-C property assignment never reloads the value following a store. 1879 if (LHS.isPropertyRef() || LHS.isKVCRef()) 1880 return RHS; 1881 1882 // If the lvalue is non-volatile, return the computed value of the assignment. 1883 if (!LHS.isVolatileQualified()) 1884 return RHS; 1885 1886 // Otherwise, reload the value. 1887 return EmitLoadOfLValue(LHS, E->getType()); 1888} 1889 1890Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 1891 const llvm::Type *ResTy = ConvertType(E->getType()); 1892 1893 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 1894 // If we have 1 && X, just emit X without inserting the control flow. 1895 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1896 if (Cond == 1) { // If we have 1 && X, just emit X. 1897 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1898 // ZExt result to int or bool. 1899 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 1900 } 1901 1902 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 1903 if (!CGF.ContainsLabel(E->getRHS())) 1904 return llvm::Constant::getNullValue(ResTy); 1905 } 1906 1907 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 1908 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 1909 1910 // Branch on the LHS first. If it is false, go to the failure (cont) block. 1911 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 1912 1913 // Any edges into the ContBlock are now from an (indeterminate number of) 1914 // edges from this first condition. All of these values will be false. Start 1915 // setting up the PHI node in the Cont Block for this. 1916 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1917 "", ContBlock); 1918 PN->reserveOperandSpace(2); // Normal case, two inputs. 1919 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1920 PI != PE; ++PI) 1921 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 1922 1923 CGF.BeginConditionalBranch(); 1924 CGF.EmitBlock(RHSBlock); 1925 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1926 CGF.EndConditionalBranch(); 1927 1928 // Reaquire the RHS block, as there may be subblocks inserted. 1929 RHSBlock = Builder.GetInsertBlock(); 1930 1931 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1932 // into the phi node for the edge with the value of RHSCond. 1933 CGF.EmitBlock(ContBlock); 1934 PN->addIncoming(RHSCond, RHSBlock); 1935 1936 // ZExt result to int. 1937 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); 1938} 1939 1940Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 1941 const llvm::Type *ResTy = ConvertType(E->getType()); 1942 1943 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 1944 // If we have 0 || X, just emit X without inserting the control flow. 1945 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1946 if (Cond == -1) { // If we have 0 || X, just emit X. 1947 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1948 // ZExt result to int or bool. 1949 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 1950 } 1951 1952 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 1953 if (!CGF.ContainsLabel(E->getRHS())) 1954 return llvm::ConstantInt::get(ResTy, 1); 1955 } 1956 1957 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 1958 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 1959 1960 // Branch on the LHS first. If it is true, go to the success (cont) block. 1961 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 1962 1963 // Any edges into the ContBlock are now from an (indeterminate number of) 1964 // edges from this first condition. All of these values will be true. Start 1965 // setting up the PHI node in the Cont Block for this. 1966 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1967 "", ContBlock); 1968 PN->reserveOperandSpace(2); // Normal case, two inputs. 1969 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1970 PI != PE; ++PI) 1971 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 1972 1973 CGF.BeginConditionalBranch(); 1974 1975 // Emit the RHS condition as a bool value. 1976 CGF.EmitBlock(RHSBlock); 1977 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1978 1979 CGF.EndConditionalBranch(); 1980 1981 // Reaquire the RHS block, as there may be subblocks inserted. 1982 RHSBlock = Builder.GetInsertBlock(); 1983 1984 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1985 // into the phi node for the edge with the value of RHSCond. 1986 CGF.EmitBlock(ContBlock); 1987 PN->addIncoming(RHSCond, RHSBlock); 1988 1989 // ZExt result to int. 1990 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 1991} 1992 1993Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 1994 CGF.EmitStmt(E->getLHS()); 1995 CGF.EnsureInsertPoint(); 1996 return Visit(E->getRHS()); 1997} 1998 1999//===----------------------------------------------------------------------===// 2000// Other Operators 2001//===----------------------------------------------------------------------===// 2002 2003/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 2004/// expression is cheap enough and side-effect-free enough to evaluate 2005/// unconditionally instead of conditionally. This is used to convert control 2006/// flow into selects in some cases. 2007static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 2008 CodeGenFunction &CGF) { 2009 if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) 2010 return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr(), CGF); 2011 2012 // TODO: Allow anything we can constant fold to an integer or fp constant. 2013 if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || 2014 isa<FloatingLiteral>(E)) 2015 return true; 2016 2017 // Non-volatile automatic variables too, to get "cond ? X : Y" where 2018 // X and Y are local variables. 2019 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 2020 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 2021 if (VD->hasLocalStorage() && !(CGF.getContext() 2022 .getCanonicalType(VD->getType()) 2023 .isVolatileQualified())) 2024 return true; 2025 2026 return false; 2027} 2028 2029 2030Value *ScalarExprEmitter:: 2031VisitConditionalOperator(const ConditionalOperator *E) { 2032 TestAndClearIgnoreResultAssign(); 2033 // If the condition constant folds and can be elided, try to avoid emitting 2034 // the condition and the dead arm. 2035 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ 2036 Expr *Live = E->getLHS(), *Dead = E->getRHS(); 2037 if (Cond == -1) 2038 std::swap(Live, Dead); 2039 2040 // If the dead side doesn't have labels we need, and if the Live side isn't 2041 // the gnu missing ?: extension (which we could handle, but don't bother 2042 // to), just emit the Live part. 2043 if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part 2044 Live) // Live part isn't missing. 2045 return Visit(Live); 2046 } 2047 2048 2049 // If this is a really simple expression (like x ? 4 : 5), emit this as a 2050 // select instead of as control flow. We can only do this if it is cheap and 2051 // safe to evaluate the LHS and RHS unconditionally. 2052 if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS(), 2053 CGF) && 2054 isCheapEnoughToEvaluateUnconditionally(E->getRHS(), CGF)) { 2055 llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); 2056 llvm::Value *LHS = Visit(E->getLHS()); 2057 llvm::Value *RHS = Visit(E->getRHS()); 2058 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 2059 } 2060 2061 if (!E->getLHS() && CGF.getContext().getLangOptions().CPlusPlus) { 2062 // Does not support GNU missing condition extension in C++ yet (see #7726) 2063 CGF.ErrorUnsupported(E, "conditional operator with missing LHS"); 2064 return llvm::UndefValue::get(ConvertType(E->getType())); 2065 } 2066 2067 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 2068 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 2069 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 2070 Value *CondVal = 0; 2071 2072 // If we don't have the GNU missing condition extension, emit a branch on bool 2073 // the normal way. 2074 if (E->getLHS()) { 2075 // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for 2076 // the branch on bool. 2077 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); 2078 } else { 2079 // Otherwise, for the ?: extension, evaluate the conditional and then 2080 // convert it to bool the hard way. We do this explicitly because we need 2081 // the unconverted value for the missing middle value of the ?:. 2082 CondVal = CGF.EmitScalarExpr(E->getCond()); 2083 2084 // In some cases, EmitScalarConversion will delete the "CondVal" expression 2085 // if there are no extra uses (an optimization). Inhibit this by making an 2086 // extra dead use, because we're going to add a use of CondVal later. We 2087 // don't use the builder for this, because we don't want it to get optimized 2088 // away. This leaves dead code, but the ?: extension isn't common. 2089 new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", 2090 Builder.GetInsertBlock()); 2091 2092 Value *CondBoolVal = 2093 CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 2094 CGF.getContext().BoolTy); 2095 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 2096 } 2097 2098 CGF.BeginConditionalBranch(); 2099 CGF.EmitBlock(LHSBlock); 2100 2101 // Handle the GNU extension for missing LHS. 2102 Value *LHS; 2103 if (E->getLHS()) 2104 LHS = Visit(E->getLHS()); 2105 else // Perform promotions, to handle cases like "short ?: int" 2106 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); 2107 2108 CGF.EndConditionalBranch(); 2109 LHSBlock = Builder.GetInsertBlock(); 2110 CGF.EmitBranch(ContBlock); 2111 2112 CGF.BeginConditionalBranch(); 2113 CGF.EmitBlock(RHSBlock); 2114 2115 Value *RHS = Visit(E->getRHS()); 2116 CGF.EndConditionalBranch(); 2117 RHSBlock = Builder.GetInsertBlock(); 2118 CGF.EmitBranch(ContBlock); 2119 2120 CGF.EmitBlock(ContBlock); 2121 2122 // If the LHS or RHS is a throw expression, it will be legitimately null. 2123 if (!LHS) 2124 return RHS; 2125 if (!RHS) 2126 return LHS; 2127 2128 // Create a PHI node for the real part. 2129 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 2130 PN->reserveOperandSpace(2); 2131 PN->addIncoming(LHS, LHSBlock); 2132 PN->addIncoming(RHS, RHSBlock); 2133 return PN; 2134} 2135 2136Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 2137 return Visit(E->getChosenSubExpr(CGF.getContext())); 2138} 2139 2140Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 2141 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 2142 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 2143 2144 // If EmitVAArg fails, we fall back to the LLVM instruction. 2145 if (!ArgPtr) 2146 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 2147 2148 // FIXME Volatility. 2149 return Builder.CreateLoad(ArgPtr); 2150} 2151 2152Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { 2153 return CGF.BuildBlockLiteralTmp(BE); 2154} 2155 2156//===----------------------------------------------------------------------===// 2157// Entry Point into this File 2158//===----------------------------------------------------------------------===// 2159 2160/// EmitScalarExpr - Emit the computation of the specified expression of scalar 2161/// type, ignoring the result. 2162Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 2163 assert(E && !hasAggregateLLVMType(E->getType()) && 2164 "Invalid scalar expression to emit"); 2165 2166 return ScalarExprEmitter(*this, IgnoreResultAssign) 2167 .Visit(const_cast<Expr*>(E)); 2168} 2169 2170/// EmitScalarConversion - Emit a conversion from the specified type to the 2171/// specified destination type, both of which are LLVM scalar types. 2172Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 2173 QualType DstTy) { 2174 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 2175 "Invalid scalar expression to emit"); 2176 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 2177} 2178 2179/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 2180/// type to the specified destination type, where the destination type is an 2181/// LLVM scalar type. 2182Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 2183 QualType SrcTy, 2184 QualType DstTy) { 2185 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 2186 "Invalid complex -> scalar conversion"); 2187 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 2188 DstTy); 2189} 2190 2191 2192llvm::Value *CodeGenFunction:: 2193EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 2194 bool isInc, bool isPre) { 2195 return ScalarExprEmitter(*this).EmitScalarPrePostIncDec(E, LV, isInc, isPre); 2196} 2197 2198LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) { 2199 llvm::Value *V; 2200 // object->isa or (*object).isa 2201 // Generate code as for: *(Class*)object 2202 // build Class* type 2203 const llvm::Type *ClassPtrTy = ConvertType(E->getType()); 2204 2205 Expr *BaseExpr = E->getBase(); 2206 if (BaseExpr->isLvalue(getContext()) != Expr::LV_Valid) { 2207 V = CreateTempAlloca(ClassPtrTy, "resval"); 2208 llvm::Value *Src = EmitScalarExpr(BaseExpr); 2209 Builder.CreateStore(Src, V); 2210 V = ScalarExprEmitter(*this).EmitLoadOfLValue( 2211 MakeAddrLValue(V, E->getType()), E->getType()); 2212 } else { 2213 if (E->isArrow()) 2214 V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr); 2215 else 2216 V = EmitLValue(BaseExpr).getAddress(); 2217 } 2218 2219 // build Class* type 2220 ClassPtrTy = ClassPtrTy->getPointerTo(); 2221 V = Builder.CreateBitCast(V, ClassPtrTy); 2222 return MakeAddrLValue(V, E->getType()); 2223} 2224 2225 2226LValue CodeGenFunction::EmitCompoundAssignOperatorLValue( 2227 const CompoundAssignOperator *E) { 2228 ScalarExprEmitter Scalar(*this); 2229 Value *Result = 0; 2230 switch (E->getOpcode()) { 2231#define COMPOUND_OP(Op) \ 2232 case BinaryOperator::Op##Assign: \ 2233 return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \ 2234 Result) 2235 COMPOUND_OP(Mul); 2236 COMPOUND_OP(Div); 2237 COMPOUND_OP(Rem); 2238 COMPOUND_OP(Add); 2239 COMPOUND_OP(Sub); 2240 COMPOUND_OP(Shl); 2241 COMPOUND_OP(Shr); 2242 COMPOUND_OP(And); 2243 COMPOUND_OP(Xor); 2244 COMPOUND_OP(Or); 2245#undef COMPOUND_OP 2246 2247 case BinaryOperator::PtrMemD: 2248 case BinaryOperator::PtrMemI: 2249 case BinaryOperator::Mul: 2250 case BinaryOperator::Div: 2251 case BinaryOperator::Rem: 2252 case BinaryOperator::Add: 2253 case BinaryOperator::Sub: 2254 case BinaryOperator::Shl: 2255 case BinaryOperator::Shr: 2256 case BinaryOperator::LT: 2257 case BinaryOperator::GT: 2258 case BinaryOperator::LE: 2259 case BinaryOperator::GE: 2260 case BinaryOperator::EQ: 2261 case BinaryOperator::NE: 2262 case BinaryOperator::And: 2263 case BinaryOperator::Xor: 2264 case BinaryOperator::Or: 2265 case BinaryOperator::LAnd: 2266 case BinaryOperator::LOr: 2267 case BinaryOperator::Assign: 2268 case BinaryOperator::Comma: 2269 assert(false && "Not valid compound assignment operators"); 2270 break; 2271 } 2272 2273 llvm_unreachable("Unhandled compound assignment operator"); 2274} 2275