CGExprScalar.cpp revision 98294def01c97e127fa6d812ebd944d37212828a
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 "CGObjCRuntime.h" 17#include "CodeGenModule.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/DeclObjC.h" 20#include "clang/AST/RecordLayout.h" 21#include "clang/AST/StmtVisitor.h" 22#include "clang/Basic/TargetInfo.h" 23#include "llvm/Constants.h" 24#include "llvm/Function.h" 25#include "llvm/GlobalVariable.h" 26#include "llvm/Intrinsics.h" 27#include "llvm/Module.h" 28#include "llvm/Support/CFG.h" 29#include "llvm/Target/TargetData.h" 30#include <cstdarg> 31 32using namespace clang; 33using namespace CodeGen; 34using llvm::Value; 35 36//===----------------------------------------------------------------------===// 37// Scalar Expression Emitter 38//===----------------------------------------------------------------------===// 39 40struct BinOpInfo { 41 Value *LHS; 42 Value *RHS; 43 QualType Ty; // Computation Type. 44 BinaryOperator::Opcode Opcode; // Opcode of BinOp to perform 45 const Expr *E; // Entire expr, for error unsupported. May not be binop. 46}; 47 48namespace { 49class ScalarExprEmitter 50 : public StmtVisitor<ScalarExprEmitter, Value*> { 51 CodeGenFunction &CGF; 52 CGBuilderTy &Builder; 53 bool IgnoreResultAssign; 54 llvm::LLVMContext &VMContext; 55public: 56 57 ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false) 58 : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira), 59 VMContext(cgf.getLLVMContext()) { 60 } 61 62 //===--------------------------------------------------------------------===// 63 // Utilities 64 //===--------------------------------------------------------------------===// 65 66 bool TestAndClearIgnoreResultAssign() { 67 bool I = IgnoreResultAssign; 68 IgnoreResultAssign = false; 69 return I; 70 } 71 72 const llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); } 73 LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); } 74 LValue EmitCheckedLValue(const Expr *E) { return CGF.EmitCheckedLValue(E); } 75 76 Value *EmitLoadOfLValue(LValue LV, QualType T) { 77 return CGF.EmitLoadOfLValue(LV, T).getScalarVal(); 78 } 79 80 /// EmitLoadOfLValue - Given an expression with complex type that represents a 81 /// value l-value, this method emits the address of the l-value, then loads 82 /// and returns the result. 83 Value *EmitLoadOfLValue(const Expr *E) { 84 return EmitLoadOfLValue(EmitCheckedLValue(E), E->getType()); 85 } 86 87 /// EmitConversionToBool - Convert the specified expression value to a 88 /// boolean (i1) truth value. This is equivalent to "Val != 0". 89 Value *EmitConversionToBool(Value *Src, QualType DstTy); 90 91 /// EmitScalarConversion - Emit a conversion from the specified type to the 92 /// specified destination type, both of which are LLVM scalar types. 93 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); 94 95 /// EmitComplexToScalarConversion - Emit a conversion from the specified 96 /// complex type to the specified destination type, where the destination type 97 /// is an LLVM scalar type. 98 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 99 QualType SrcTy, QualType DstTy); 100 101 /// EmitNullValue - Emit a value that corresponds to null for the given type. 102 Value *EmitNullValue(QualType Ty); 103 104 //===--------------------------------------------------------------------===// 105 // Visitor Methods 106 //===--------------------------------------------------------------------===// 107 108 Value *VisitStmt(Stmt *S) { 109 S->dump(CGF.getContext().getSourceManager()); 110 assert(0 && "Stmt can't have complex result type!"); 111 return 0; 112 } 113 Value *VisitExpr(Expr *S); 114 115 Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); } 116 117 // Leaves. 118 Value *VisitIntegerLiteral(const IntegerLiteral *E) { 119 return llvm::ConstantInt::get(VMContext, E->getValue()); 120 } 121 Value *VisitFloatingLiteral(const FloatingLiteral *E) { 122 return llvm::ConstantFP::get(VMContext, E->getValue()); 123 } 124 Value *VisitCharacterLiteral(const CharacterLiteral *E) { 125 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 126 } 127 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 128 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 129 } 130 Value *VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) { 131 return EmitNullValue(E->getType()); 132 } 133 Value *VisitGNUNullExpr(const GNUNullExpr *E) { 134 return EmitNullValue(E->getType()); 135 } 136 Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { 137 return llvm::ConstantInt::get(ConvertType(E->getType()), 138 CGF.getContext().typesAreCompatible( 139 E->getArgType1(), E->getArgType2())); 140 } 141 Value *VisitOffsetOfExpr(OffsetOfExpr *E); 142 Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); 143 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 144 llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel()); 145 return Builder.CreateBitCast(V, ConvertType(E->getType())); 146 } 147 148 // l-values. 149 Value *VisitDeclRefExpr(DeclRefExpr *E) { 150 Expr::EvalResult Result; 151 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 152 assert(!Result.HasSideEffects && "Constant declref with side-effect?!"); 153 llvm::ConstantInt *CI 154 = llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 155 CGF.EmitDeclRefExprDbgValue(E, CI); 156 return CI; 157 } 158 return EmitLoadOfLValue(E); 159 } 160 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 161 return CGF.EmitObjCSelectorExpr(E); 162 } 163 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 164 return CGF.EmitObjCProtocolExpr(E); 165 } 166 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 167 return EmitLoadOfLValue(E); 168 } 169 Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { 170 return EmitLoadOfLValue(E); 171 } 172 Value *VisitObjCImplicitSetterGetterRefExpr( 173 ObjCImplicitSetterGetterRefExpr *E) { 174 return EmitLoadOfLValue(E); 175 } 176 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 177 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 178 } 179 180 Value *VisitObjCIsaExpr(ObjCIsaExpr *E) { 181 LValue LV = CGF.EmitObjCIsaExpr(E); 182 Value *V = CGF.EmitLoadOfLValue(LV, E->getType()).getScalarVal(); 183 return V; 184 } 185 186 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 187 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 188 Value *VisitMemberExpr(MemberExpr *E); 189 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 190 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 191 return EmitLoadOfLValue(E); 192 } 193 194 Value *VisitInitListExpr(InitListExpr *E); 195 196 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { 197 return CGF.CGM.EmitNullConstant(E->getType()); 198 } 199 Value *VisitCastExpr(CastExpr *E) { 200 // Make sure to evaluate VLA bounds now so that we have them for later. 201 if (E->getType()->isVariablyModifiedType()) 202 CGF.EmitVLASize(E->getType()); 203 204 return EmitCastExpr(E); 205 } 206 Value *EmitCastExpr(CastExpr *E); 207 208 Value *VisitCallExpr(const CallExpr *E) { 209 if (E->getCallReturnType()->isReferenceType()) 210 return EmitLoadOfLValue(E); 211 212 return CGF.EmitCallExpr(E).getScalarVal(); 213 } 214 215 Value *VisitStmtExpr(const StmtExpr *E); 216 217 Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E); 218 219 // Unary Operators. 220 Value *VisitUnaryPostDec(const UnaryOperator *E) { 221 LValue LV = EmitLValue(E->getSubExpr()); 222 return EmitScalarPrePostIncDec(E, LV, false, false); 223 } 224 Value *VisitUnaryPostInc(const UnaryOperator *E) { 225 LValue LV = EmitLValue(E->getSubExpr()); 226 return EmitScalarPrePostIncDec(E, LV, true, false); 227 } 228 Value *VisitUnaryPreDec(const UnaryOperator *E) { 229 LValue LV = EmitLValue(E->getSubExpr()); 230 return EmitScalarPrePostIncDec(E, LV, false, true); 231 } 232 Value *VisitUnaryPreInc(const UnaryOperator *E) { 233 LValue LV = EmitLValue(E->getSubExpr()); 234 return EmitScalarPrePostIncDec(E, LV, true, true); 235 } 236 237 llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 238 bool isInc, bool isPre); 239 240 241 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 242 // If the sub-expression is an instance member reference, 243 // EmitDeclRefLValue will magically emit it with the appropriate 244 // value as the "address". 245 return EmitLValue(E->getSubExpr()).getAddress(); 246 } 247 Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } 248 Value *VisitUnaryPlus(const UnaryOperator *E) { 249 // This differs from gcc, though, most likely due to a bug in gcc. 250 TestAndClearIgnoreResultAssign(); 251 return Visit(E->getSubExpr()); 252 } 253 Value *VisitUnaryMinus (const UnaryOperator *E); 254 Value *VisitUnaryNot (const UnaryOperator *E); 255 Value *VisitUnaryLNot (const UnaryOperator *E); 256 Value *VisitUnaryReal (const UnaryOperator *E); 257 Value *VisitUnaryImag (const UnaryOperator *E); 258 Value *VisitUnaryExtension(const UnaryOperator *E) { 259 return Visit(E->getSubExpr()); 260 } 261 262 // C++ 263 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 264 return Visit(DAE->getExpr()); 265 } 266 Value *VisitCXXThisExpr(CXXThisExpr *TE) { 267 return CGF.LoadCXXThis(); 268 } 269 270 Value *VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) { 271 return CGF.EmitCXXExprWithTemporaries(E).getScalarVal(); 272 } 273 Value *VisitCXXNewExpr(const CXXNewExpr *E) { 274 return CGF.EmitCXXNewExpr(E); 275 } 276 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { 277 CGF.EmitCXXDeleteExpr(E); 278 return 0; 279 } 280 Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) { 281 return llvm::ConstantInt::get(Builder.getInt1Ty(), 282 E->EvaluateTrait(CGF.getContext())); 283 } 284 285 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { 286 // C++ [expr.pseudo]p1: 287 // The result shall only be used as the operand for the function call 288 // operator (), and the result of such a call has type void. The only 289 // effect is the evaluation of the postfix-expression before the dot or 290 // arrow. 291 CGF.EmitScalarExpr(E->getBase()); 292 return 0; 293 } 294 295 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { 296 return EmitNullValue(E->getType()); 297 } 298 299 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { 300 CGF.EmitCXXThrowExpr(E); 301 return 0; 302 } 303 304 Value *VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) { 305 return llvm::ConstantInt::get(Builder.getInt1Ty(), E->getValue()); 306 } 307 308 // Binary Operators. 309 Value *EmitMul(const BinOpInfo &Ops) { 310 if (Ops.Ty->hasSignedIntegerRepresentation()) { 311 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 312 case LangOptions::SOB_Undefined: 313 return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul"); 314 case LangOptions::SOB_Defined: 315 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 316 case LangOptions::SOB_Trapping: 317 return EmitOverflowCheckedBinOp(Ops); 318 } 319 } 320 321 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 322 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 323 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 324 } 325 /// Create a binary op that checks for overflow. 326 /// Currently only supports +, - and *. 327 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 328 Value *EmitDiv(const BinOpInfo &Ops); 329 Value *EmitRem(const BinOpInfo &Ops); 330 Value *EmitAdd(const BinOpInfo &Ops); 331 Value *EmitSub(const BinOpInfo &Ops); 332 Value *EmitShl(const BinOpInfo &Ops); 333 Value *EmitShr(const BinOpInfo &Ops); 334 Value *EmitAnd(const BinOpInfo &Ops) { 335 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 336 } 337 Value *EmitXor(const BinOpInfo &Ops) { 338 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 339 } 340 Value *EmitOr (const BinOpInfo &Ops) { 341 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 342 } 343 344 BinOpInfo EmitBinOps(const BinaryOperator *E); 345 LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E, 346 Value *(ScalarExprEmitter::*F)(const BinOpInfo &), 347 Value *&Result); 348 349 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 350 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 351 352 // Binary operators and binary compound assignment operators. 353#define HANDLEBINOP(OP) \ 354 Value *VisitBin ## OP(const BinaryOperator *E) { \ 355 return Emit ## OP(EmitBinOps(E)); \ 356 } \ 357 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 358 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 359 } 360 HANDLEBINOP(Mul) 361 HANDLEBINOP(Div) 362 HANDLEBINOP(Rem) 363 HANDLEBINOP(Add) 364 HANDLEBINOP(Sub) 365 HANDLEBINOP(Shl) 366 HANDLEBINOP(Shr) 367 HANDLEBINOP(And) 368 HANDLEBINOP(Xor) 369 HANDLEBINOP(Or) 370#undef HANDLEBINOP 371 372 // Comparisons. 373 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 374 unsigned SICmpOpc, unsigned FCmpOpc); 375#define VISITCOMP(CODE, UI, SI, FP) \ 376 Value *VisitBin##CODE(const BinaryOperator *E) { \ 377 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 378 llvm::FCmpInst::FP); } 379 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT) 380 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT) 381 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE) 382 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE) 383 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ) 384 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE) 385#undef VISITCOMP 386 387 Value *VisitBinAssign (const BinaryOperator *E); 388 389 Value *VisitBinLAnd (const BinaryOperator *E); 390 Value *VisitBinLOr (const BinaryOperator *E); 391 Value *VisitBinComma (const BinaryOperator *E); 392 393 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } 394 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); } 395 396 // Other Operators. 397 Value *VisitBlockExpr(const BlockExpr *BE); 398 Value *VisitConditionalOperator(const ConditionalOperator *CO); 399 Value *VisitChooseExpr(ChooseExpr *CE); 400 Value *VisitVAArgExpr(VAArgExpr *VE); 401 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 402 return CGF.EmitObjCStringLiteral(E); 403 } 404}; 405} // end anonymous namespace. 406 407//===----------------------------------------------------------------------===// 408// Utilities 409//===----------------------------------------------------------------------===// 410 411/// EmitConversionToBool - Convert the specified expression value to a 412/// boolean (i1) truth value. This is equivalent to "Val != 0". 413Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 414 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs"); 415 416 if (SrcType->isRealFloatingType()) { 417 // Compare against 0.0 for fp scalars. 418 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 419 return Builder.CreateFCmpUNE(Src, Zero, "tobool"); 420 } 421 422 if (const MemberPointerType *MPT = dyn_cast<MemberPointerType>(SrcType)) 423 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, Src, MPT); 424 425 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 426 "Unknown scalar type to convert"); 427 428 // Because of the type rules of C, we often end up computing a logical value, 429 // then zero extending it to int, then wanting it as a logical value again. 430 // Optimize this common case. 431 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) { 432 if (ZI->getOperand(0)->getType() == 433 llvm::Type::getInt1Ty(CGF.getLLVMContext())) { 434 Value *Result = ZI->getOperand(0); 435 // If there aren't any more uses, zap the instruction to save space. 436 // Note that there can be more uses, for example if this 437 // is the result of an assignment. 438 if (ZI->use_empty()) 439 ZI->eraseFromParent(); 440 return Result; 441 } 442 } 443 444 // Compare against an integer or pointer null. 445 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 446 return Builder.CreateICmpNE(Src, Zero, "tobool"); 447} 448 449/// EmitScalarConversion - Emit a conversion from the specified type to the 450/// specified destination type, both of which are LLVM scalar types. 451Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 452 QualType DstType) { 453 SrcType = CGF.getContext().getCanonicalType(SrcType); 454 DstType = CGF.getContext().getCanonicalType(DstType); 455 if (SrcType == DstType) return Src; 456 457 if (DstType->isVoidType()) return 0; 458 459 // Handle conversions to bool first, they are special: comparisons against 0. 460 if (DstType->isBooleanType()) 461 return EmitConversionToBool(Src, SrcType); 462 463 const llvm::Type *DstTy = ConvertType(DstType); 464 465 // Ignore conversions like int -> uint. 466 if (Src->getType() == DstTy) 467 return Src; 468 469 // Handle pointer conversions next: pointers can only be converted to/from 470 // other pointers and integers. Check for pointer types in terms of LLVM, as 471 // some native types (like Obj-C id) may map to a pointer type. 472 if (isa<llvm::PointerType>(DstTy)) { 473 // The source value may be an integer, or a pointer. 474 if (isa<llvm::PointerType>(Src->getType())) 475 return Builder.CreateBitCast(Src, DstTy, "conv"); 476 477 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 478 // First, convert to the correct width so that we control the kind of 479 // extension. 480 const llvm::Type *MiddleTy = CGF.IntPtrTy; 481 bool InputSigned = SrcType->isSignedIntegerType(); 482 llvm::Value* IntResult = 483 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 484 // Then, cast to pointer. 485 return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); 486 } 487 488 if (isa<llvm::PointerType>(Src->getType())) { 489 // Must be an ptr to int cast. 490 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 491 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 492 } 493 494 // A scalar can be splatted to an extended vector of the same element type 495 if (DstType->isExtVectorType() && !SrcType->isVectorType()) { 496 // Cast the scalar to element type 497 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType(); 498 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 499 500 // Insert the element in element zero of an undef vector 501 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 502 llvm::Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, 0); 503 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 504 505 // Splat the element across to all elements 506 llvm::SmallVector<llvm::Constant*, 16> Args; 507 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 508 for (unsigned i = 0; i < NumElements; i++) 509 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 0)); 510 511 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 512 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 513 return Yay; 514 } 515 516 // Allow bitcast from vector to integer/fp of the same size. 517 if (isa<llvm::VectorType>(Src->getType()) || 518 isa<llvm::VectorType>(DstTy)) 519 return Builder.CreateBitCast(Src, DstTy, "conv"); 520 521 // Finally, we have the arithmetic types: real int/float. 522 if (isa<llvm::IntegerType>(Src->getType())) { 523 bool InputSigned = SrcType->isSignedIntegerType(); 524 if (isa<llvm::IntegerType>(DstTy)) 525 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 526 else if (InputSigned) 527 return Builder.CreateSIToFP(Src, DstTy, "conv"); 528 else 529 return Builder.CreateUIToFP(Src, DstTy, "conv"); 530 } 531 532 assert(Src->getType()->isFloatingPointTy() && "Unknown real conversion"); 533 if (isa<llvm::IntegerType>(DstTy)) { 534 if (DstType->isSignedIntegerType()) 535 return Builder.CreateFPToSI(Src, DstTy, "conv"); 536 else 537 return Builder.CreateFPToUI(Src, DstTy, "conv"); 538 } 539 540 assert(DstTy->isFloatingPointTy() && "Unknown real conversion"); 541 if (DstTy->getTypeID() < Src->getType()->getTypeID()) 542 return Builder.CreateFPTrunc(Src, DstTy, "conv"); 543 else 544 return Builder.CreateFPExt(Src, DstTy, "conv"); 545} 546 547/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 548/// type to the specified destination type, where the destination type is an 549/// LLVM scalar type. 550Value *ScalarExprEmitter:: 551EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 552 QualType SrcTy, QualType DstTy) { 553 // Get the source element type. 554 SrcTy = SrcTy->getAs<ComplexType>()->getElementType(); 555 556 // Handle conversions to bool first, they are special: comparisons against 0. 557 if (DstTy->isBooleanType()) { 558 // Complex != 0 -> (Real != 0) | (Imag != 0) 559 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 560 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 561 return Builder.CreateOr(Src.first, Src.second, "tobool"); 562 } 563 564 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 565 // the imaginary part of the complex value is discarded and the value of the 566 // real part is converted according to the conversion rules for the 567 // corresponding real type. 568 return EmitScalarConversion(Src.first, SrcTy, DstTy); 569} 570 571Value *ScalarExprEmitter::EmitNullValue(QualType Ty) { 572 if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>()) 573 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 574 575 return llvm::Constant::getNullValue(ConvertType(Ty)); 576} 577 578//===----------------------------------------------------------------------===// 579// Visitor Methods 580//===----------------------------------------------------------------------===// 581 582Value *ScalarExprEmitter::VisitExpr(Expr *E) { 583 CGF.ErrorUnsupported(E, "scalar expression"); 584 if (E->getType()->isVoidType()) 585 return 0; 586 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 587} 588 589Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 590 // Vector Mask Case 591 if (E->getNumSubExprs() == 2 || 592 (E->getNumSubExprs() == 3 && E->getExpr(2)->getType()->isVectorType())) { 593 Value *LHS = CGF.EmitScalarExpr(E->getExpr(0)); 594 Value *RHS = CGF.EmitScalarExpr(E->getExpr(1)); 595 Value *Mask; 596 597 const llvm::VectorType *LTy = cast<llvm::VectorType>(LHS->getType()); 598 unsigned LHSElts = LTy->getNumElements(); 599 600 if (E->getNumSubExprs() == 3) { 601 Mask = CGF.EmitScalarExpr(E->getExpr(2)); 602 603 // Shuffle LHS & RHS into one input vector. 604 llvm::SmallVector<llvm::Constant*, 32> concat; 605 for (unsigned i = 0; i != LHSElts; ++i) { 606 concat.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 2*i)); 607 concat.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 2*i+1)); 608 } 609 610 Value* CV = llvm::ConstantVector::get(concat.begin(), concat.size()); 611 LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat"); 612 LHSElts *= 2; 613 } else { 614 Mask = RHS; 615 } 616 617 const llvm::VectorType *MTy = cast<llvm::VectorType>(Mask->getType()); 618 llvm::Constant* EltMask; 619 620 // Treat vec3 like vec4. 621 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) 622 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 623 (1 << llvm::Log2_32(LHSElts+2))-1); 624 else if ((LHSElts == 3) && (E->getNumSubExprs() == 2)) 625 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 626 (1 << llvm::Log2_32(LHSElts+1))-1); 627 else 628 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 629 (1 << llvm::Log2_32(LHSElts))-1); 630 631 // Mask off the high bits of each shuffle index. 632 llvm::SmallVector<llvm::Constant *, 32> MaskV; 633 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) 634 MaskV.push_back(EltMask); 635 636 Value* MaskBits = llvm::ConstantVector::get(MaskV.begin(), MaskV.size()); 637 Mask = Builder.CreateAnd(Mask, MaskBits, "mask"); 638 639 // newv = undef 640 // mask = mask & maskbits 641 // for each elt 642 // n = extract mask i 643 // x = extract val n 644 // newv = insert newv, x, i 645 const llvm::VectorType *RTy = llvm::VectorType::get(LTy->getElementType(), 646 MTy->getNumElements()); 647 Value* NewV = llvm::UndefValue::get(RTy); 648 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) { 649 Value *Indx = llvm::ConstantInt::get(CGF.Int32Ty, i); 650 Indx = Builder.CreateExtractElement(Mask, Indx, "shuf_idx"); 651 Indx = Builder.CreateZExt(Indx, CGF.Int32Ty, "idx_zext"); 652 653 // Handle vec3 special since the index will be off by one for the RHS. 654 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) { 655 Value *cmpIndx, *newIndx; 656 cmpIndx = Builder.CreateICmpUGT(Indx, 657 llvm::ConstantInt::get(CGF.Int32Ty, 3), 658 "cmp_shuf_idx"); 659 newIndx = Builder.CreateSub(Indx, llvm::ConstantInt::get(CGF.Int32Ty,1), 660 "shuf_idx_adj"); 661 Indx = Builder.CreateSelect(cmpIndx, newIndx, Indx, "sel_shuf_idx"); 662 } 663 Value *VExt = Builder.CreateExtractElement(LHS, Indx, "shuf_elt"); 664 NewV = Builder.CreateInsertElement(NewV, VExt, Indx, "shuf_ins"); 665 } 666 return NewV; 667 } 668 669 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 670 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 671 672 // Handle vec3 special since the index will be off by one for the RHS. 673 llvm::SmallVector<llvm::Constant*, 32> indices; 674 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 675 llvm::Constant *C = cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i))); 676 const llvm::VectorType *VTy = cast<llvm::VectorType>(V1->getType()); 677 if (VTy->getNumElements() == 3) { 678 if (llvm::ConstantInt *CI = dyn_cast<llvm::ConstantInt>(C)) { 679 uint64_t cVal = CI->getZExtValue(); 680 if (cVal > 3) { 681 C = llvm::ConstantInt::get(C->getType(), cVal-1); 682 } 683 } 684 } 685 indices.push_back(C); 686 } 687 688 Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); 689 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 690} 691Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { 692 Expr::EvalResult Result; 693 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 694 if (E->isArrow()) 695 CGF.EmitScalarExpr(E->getBase()); 696 else 697 EmitLValue(E->getBase()); 698 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 699 } 700 return EmitLoadOfLValue(E); 701} 702 703Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 704 TestAndClearIgnoreResultAssign(); 705 706 // Emit subscript expressions in rvalue context's. For most cases, this just 707 // loads the lvalue formed by the subscript expr. However, we have to be 708 // careful, because the base of a vector subscript is occasionally an rvalue, 709 // so we can't get it as an lvalue. 710 if (!E->getBase()->getType()->isVectorType()) 711 return EmitLoadOfLValue(E); 712 713 // Handle the vector case. The base must be a vector, the index must be an 714 // integer value. 715 Value *Base = Visit(E->getBase()); 716 Value *Idx = Visit(E->getIdx()); 717 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerType(); 718 Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vecidxcast"); 719 return Builder.CreateExtractElement(Base, Idx, "vecext"); 720} 721 722static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, 723 unsigned Off, const llvm::Type *I32Ty) { 724 int MV = SVI->getMaskValue(Idx); 725 if (MV == -1) 726 return llvm::UndefValue::get(I32Ty); 727 return llvm::ConstantInt::get(I32Ty, Off+MV); 728} 729 730Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) { 731 bool Ignore = TestAndClearIgnoreResultAssign(); 732 (void)Ignore; 733 assert (Ignore == false && "init list ignored"); 734 unsigned NumInitElements = E->getNumInits(); 735 736 if (E->hadArrayRangeDesignator()) 737 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 738 739 const llvm::VectorType *VType = 740 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 741 742 // We have a scalar in braces. Just use the first element. 743 if (!VType) 744 return Visit(E->getInit(0)); 745 746 unsigned ResElts = VType->getNumElements(); 747 748 // Loop over initializers collecting the Value for each, and remembering 749 // whether the source was swizzle (ExtVectorElementExpr). This will allow 750 // us to fold the shuffle for the swizzle into the shuffle for the vector 751 // initializer, since LLVM optimizers generally do not want to touch 752 // shuffles. 753 unsigned CurIdx = 0; 754 bool VIsUndefShuffle = false; 755 llvm::Value *V = llvm::UndefValue::get(VType); 756 for (unsigned i = 0; i != NumInitElements; ++i) { 757 Expr *IE = E->getInit(i); 758 Value *Init = Visit(IE); 759 llvm::SmallVector<llvm::Constant*, 16> Args; 760 761 const llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType()); 762 763 // Handle scalar elements. If the scalar initializer is actually one 764 // element of a different vector of the same width, use shuffle instead of 765 // extract+insert. 766 if (!VVT) { 767 if (isa<ExtVectorElementExpr>(IE)) { 768 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init); 769 770 if (EI->getVectorOperandType()->getNumElements() == ResElts) { 771 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand()); 772 Value *LHS = 0, *RHS = 0; 773 if (CurIdx == 0) { 774 // insert into undef -> shuffle (src, undef) 775 Args.push_back(C); 776 for (unsigned j = 1; j != ResElts; ++j) 777 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 778 779 LHS = EI->getVectorOperand(); 780 RHS = V; 781 VIsUndefShuffle = true; 782 } else if (VIsUndefShuffle) { 783 // insert into undefshuffle && size match -> shuffle (v, src) 784 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V); 785 for (unsigned j = 0; j != CurIdx; ++j) 786 Args.push_back(getMaskElt(SVV, j, 0, CGF.Int32Ty)); 787 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 788 ResElts + C->getZExtValue())); 789 for (unsigned j = CurIdx + 1; j != ResElts; ++j) 790 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 791 792 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 793 RHS = EI->getVectorOperand(); 794 VIsUndefShuffle = false; 795 } 796 if (!Args.empty()) { 797 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 798 V = Builder.CreateShuffleVector(LHS, RHS, Mask); 799 ++CurIdx; 800 continue; 801 } 802 } 803 } 804 Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, CurIdx); 805 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 806 VIsUndefShuffle = false; 807 ++CurIdx; 808 continue; 809 } 810 811 unsigned InitElts = VVT->getNumElements(); 812 813 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's 814 // input is the same width as the vector being constructed, generate an 815 // optimized shuffle of the swizzle input into the result. 816 unsigned Offset = (CurIdx == 0) ? 0 : ResElts; 817 if (isa<ExtVectorElementExpr>(IE)) { 818 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init); 819 Value *SVOp = SVI->getOperand(0); 820 const llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType()); 821 822 if (OpTy->getNumElements() == ResElts) { 823 for (unsigned j = 0; j != CurIdx; ++j) { 824 // If the current vector initializer is a shuffle with undef, merge 825 // this shuffle directly into it. 826 if (VIsUndefShuffle) { 827 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0, 828 CGF.Int32Ty)); 829 } else { 830 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); 831 } 832 } 833 for (unsigned j = 0, je = InitElts; j != je; ++j) 834 Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty)); 835 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 836 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 837 838 if (VIsUndefShuffle) 839 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 840 841 Init = SVOp; 842 } 843 } 844 845 // Extend init to result vector length, and then shuffle its contribution 846 // to the vector initializer into V. 847 if (Args.empty()) { 848 for (unsigned j = 0; j != InitElts; ++j) 849 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); 850 for (unsigned j = InitElts; j != ResElts; ++j) 851 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 852 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 853 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), 854 Mask, "vext"); 855 856 Args.clear(); 857 for (unsigned j = 0; j != CurIdx; ++j) 858 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); 859 for (unsigned j = 0; j != InitElts; ++j) 860 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j+Offset)); 861 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 862 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 863 } 864 865 // If V is undef, make sure it ends up on the RHS of the shuffle to aid 866 // merging subsequent shuffles into this one. 867 if (CurIdx == 0) 868 std::swap(V, Init); 869 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 870 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); 871 VIsUndefShuffle = isa<llvm::UndefValue>(Init); 872 CurIdx += InitElts; 873 } 874 875 // FIXME: evaluate codegen vs. shuffling against constant null vector. 876 // Emit remaining default initializers. 877 const llvm::Type *EltTy = VType->getElementType(); 878 879 // Emit remaining default initializers 880 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { 881 Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, CurIdx); 882 llvm::Value *Init = llvm::Constant::getNullValue(EltTy); 883 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 884 } 885 return V; 886} 887 888static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { 889 const Expr *E = CE->getSubExpr(); 890 891 if (CE->getCastKind() == CK_UncheckedDerivedToBase) 892 return false; 893 894 if (isa<CXXThisExpr>(E)) { 895 // We always assume that 'this' is never null. 896 return false; 897 } 898 899 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { 900 // And that glvalue casts are never null. 901 if (ICE->getValueKind() != VK_RValue) 902 return false; 903 } 904 905 return true; 906} 907 908// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 909// have to handle a more broad range of conversions than explicit casts, as they 910// handle things like function to ptr-to-function decay etc. 911Value *ScalarExprEmitter::EmitCastExpr(CastExpr *CE) { 912 Expr *E = CE->getSubExpr(); 913 QualType DestTy = CE->getType(); 914 CastKind Kind = CE->getCastKind(); 915 916 if (!DestTy->isVoidType()) 917 TestAndClearIgnoreResultAssign(); 918 919 // Since almost all cast kinds apply to scalars, this switch doesn't have 920 // a default case, so the compiler will warn on a missing case. The cases 921 // are in the same order as in the CastKind enum. 922 switch (Kind) { 923 case CK_Unknown: 924 // FIXME: All casts should have a known kind! 925 //assert(0 && "Unknown cast kind!"); 926 break; 927 928 case CK_LValueBitCast: 929 case CK_ObjCObjectLValueCast: { 930 Value *V = EmitLValue(E).getAddress(); 931 V = Builder.CreateBitCast(V, 932 ConvertType(CGF.getContext().getPointerType(DestTy))); 933 return EmitLoadOfLValue(CGF.MakeAddrLValue(V, DestTy), DestTy); 934 } 935 936 case CK_AnyPointerToObjCPointerCast: 937 case CK_AnyPointerToBlockPointerCast: 938 case CK_BitCast: { 939 Value *Src = Visit(const_cast<Expr*>(E)); 940 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 941 } 942 case CK_NoOp: 943 case CK_UserDefinedConversion: 944 return Visit(const_cast<Expr*>(E)); 945 946 case CK_BaseToDerived: { 947 const CXXRecordDecl *DerivedClassDecl = 948 DestTy->getCXXRecordDeclForPointerType(); 949 950 return CGF.GetAddressOfDerivedClass(Visit(E), DerivedClassDecl, 951 CE->path_begin(), CE->path_end(), 952 ShouldNullCheckClassCastValue(CE)); 953 } 954 case CK_UncheckedDerivedToBase: 955 case CK_DerivedToBase: { 956 const RecordType *DerivedClassTy = 957 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 958 CXXRecordDecl *DerivedClassDecl = 959 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 960 961 return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl, 962 CE->path_begin(), CE->path_end(), 963 ShouldNullCheckClassCastValue(CE)); 964 } 965 case CK_Dynamic: { 966 Value *V = Visit(const_cast<Expr*>(E)); 967 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 968 return CGF.EmitDynamicCast(V, DCE); 969 } 970 case CK_ToUnion: 971 assert(0 && "Should be unreachable!"); 972 break; 973 974 case CK_ArrayToPointerDecay: { 975 assert(E->getType()->isArrayType() && 976 "Array to pointer decay must have array source type!"); 977 978 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 979 980 // Note that VLA pointers are always decayed, so we don't need to do 981 // anything here. 982 if (!E->getType()->isVariableArrayType()) { 983 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 984 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 985 ->getElementType()) && 986 "Expected pointer to array"); 987 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 988 } 989 990 return V; 991 } 992 case CK_FunctionToPointerDecay: 993 return EmitLValue(E).getAddress(); 994 995 case CK_NullToMemberPointer: { 996 // If the subexpression's type is the C++0x nullptr_t, emit the 997 // subexpression, which may have side effects. 998 if (E->getType()->isNullPtrType()) 999 (void) Visit(E); 1000 1001 const MemberPointerType *MPT = CE->getType()->getAs<MemberPointerType>(); 1002 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 1003 } 1004 1005 case CK_BaseToDerivedMemberPointer: 1006 case CK_DerivedToBaseMemberPointer: { 1007 Value *Src = Visit(E); 1008 1009 // Note that the AST doesn't distinguish between checked and 1010 // unchecked member pointer conversions, so we always have to 1011 // implement checked conversions here. This is inefficient when 1012 // actual control flow may be required in order to perform the 1013 // check, which it is for data member pointers (but not member 1014 // function pointers on Itanium and ARM). 1015 return CGF.CGM.getCXXABI().EmitMemberPointerConversion(CGF, CE, Src); 1016 } 1017 1018 1019 case CK_ConstructorConversion: 1020 assert(0 && "Should be unreachable!"); 1021 break; 1022 1023 case CK_IntegralToPointer: { 1024 Value *Src = Visit(const_cast<Expr*>(E)); 1025 1026 // First, convert to the correct width so that we control the kind of 1027 // extension. 1028 const llvm::Type *MiddleTy = CGF.IntPtrTy; 1029 bool InputSigned = E->getType()->isSignedIntegerType(); 1030 llvm::Value* IntResult = 1031 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 1032 1033 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 1034 } 1035 case CK_PointerToIntegral: { 1036 Value *Src = Visit(const_cast<Expr*>(E)); 1037 1038 // Handle conversion to bool correctly. 1039 if (DestTy->isBooleanType()) 1040 return EmitScalarConversion(Src, E->getType(), DestTy); 1041 1042 return Builder.CreatePtrToInt(Src, ConvertType(DestTy)); 1043 } 1044 case CK_ToVoid: { 1045 if (E->Classify(CGF.getContext()).isGLValue()) { 1046 LValue LV = CGF.EmitLValue(E); 1047 if (LV.isPropertyRef()) 1048 CGF.EmitLoadOfPropertyRefLValue(LV, E->getType()); 1049 else if (LV.isKVCRef()) 1050 CGF.EmitLoadOfKVCRefLValue(LV, E->getType()); 1051 } 1052 else 1053 CGF.EmitAnyExpr(E, 0, false, true); 1054 return 0; 1055 } 1056 case CK_VectorSplat: { 1057 const llvm::Type *DstTy = ConvertType(DestTy); 1058 Value *Elt = Visit(const_cast<Expr*>(E)); 1059 1060 // Insert the element in element zero of an undef vector 1061 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 1062 llvm::Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, 0); 1063 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 1064 1065 // Splat the element across to all elements 1066 llvm::SmallVector<llvm::Constant*, 16> Args; 1067 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 1068 for (unsigned i = 0; i < NumElements; i++) 1069 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 0)); 1070 1071 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 1072 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 1073 return Yay; 1074 } 1075 case CK_IntegralCast: 1076 case CK_IntegralToFloating: 1077 case CK_FloatingToIntegral: 1078 case CK_FloatingCast: 1079 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 1080 1081 case CK_MemberPointerToBoolean: { 1082 llvm::Value *MemPtr = Visit(E); 1083 const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>(); 1084 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT); 1085 } 1086 } 1087 1088 // Handle cases where the source is an non-complex type. 1089 1090 if (!CGF.hasAggregateLLVMType(E->getType())) { 1091 Value *Src = Visit(const_cast<Expr*>(E)); 1092 1093 // Use EmitScalarConversion to perform the conversion. 1094 return EmitScalarConversion(Src, E->getType(), DestTy); 1095 } 1096 1097 if (E->getType()->isAnyComplexType()) { 1098 // Handle cases where the source is a complex type. 1099 bool IgnoreImag = true; 1100 bool IgnoreImagAssign = true; 1101 bool IgnoreReal = IgnoreResultAssign; 1102 bool IgnoreRealAssign = IgnoreResultAssign; 1103 if (DestTy->isBooleanType()) 1104 IgnoreImagAssign = IgnoreImag = false; 1105 else if (DestTy->isVoidType()) { 1106 IgnoreReal = IgnoreImag = false; 1107 IgnoreRealAssign = IgnoreImagAssign = true; 1108 } 1109 CodeGenFunction::ComplexPairTy V 1110 = CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign, 1111 IgnoreImagAssign); 1112 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 1113 } 1114 1115 // Okay, this is a cast from an aggregate. It must be a cast to void. Just 1116 // evaluate the result and return. 1117 CGF.EmitAggExpr(E, 0, false, true); 1118 return 0; 1119} 1120 1121Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 1122 return CGF.EmitCompoundStmt(*E->getSubStmt(), 1123 !E->getType()->isVoidType()).getScalarVal(); 1124} 1125 1126Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 1127 llvm::Value *V = CGF.GetAddrOfBlockDecl(E); 1128 if (E->getType().isObjCGCWeak()) 1129 return CGF.CGM.getObjCRuntime().EmitObjCWeakRead(CGF, V); 1130 return CGF.EmitLoadOfScalar(V, false, 0, E->getType()); 1131} 1132 1133//===----------------------------------------------------------------------===// 1134// Unary Operators 1135//===----------------------------------------------------------------------===// 1136 1137llvm::Value *ScalarExprEmitter:: 1138EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 1139 bool isInc, bool isPre) { 1140 1141 QualType ValTy = E->getSubExpr()->getType(); 1142 llvm::Value *InVal = EmitLoadOfLValue(LV, ValTy); 1143 1144 int AmountVal = isInc ? 1 : -1; 1145 1146 if (ValTy->isPointerType() && 1147 ValTy->getAs<PointerType>()->isVariableArrayType()) { 1148 // The amount of the addition/subtraction needs to account for the VLA size 1149 CGF.ErrorUnsupported(E, "VLA pointer inc/dec"); 1150 } 1151 1152 llvm::Value *NextVal; 1153 if (const llvm::PointerType *PT = 1154 dyn_cast<llvm::PointerType>(InVal->getType())) { 1155 llvm::Constant *Inc = llvm::ConstantInt::get(CGF.Int32Ty, AmountVal); 1156 if (!isa<llvm::FunctionType>(PT->getElementType())) { 1157 QualType PTEE = ValTy->getPointeeType(); 1158 if (const ObjCObjectType *OIT = PTEE->getAs<ObjCObjectType>()) { 1159 // Handle interface types, which are not represented with a concrete 1160 // type. 1161 int size = CGF.getContext().getTypeSize(OIT) / 8; 1162 if (!isInc) 1163 size = -size; 1164 Inc = llvm::ConstantInt::get(Inc->getType(), size); 1165 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1166 InVal = Builder.CreateBitCast(InVal, i8Ty); 1167 NextVal = Builder.CreateGEP(InVal, Inc, "add.ptr"); 1168 llvm::Value *lhs = LV.getAddress(); 1169 lhs = Builder.CreateBitCast(lhs, llvm::PointerType::getUnqual(i8Ty)); 1170 LV = CGF.MakeAddrLValue(lhs, ValTy); 1171 } else 1172 NextVal = Builder.CreateInBoundsGEP(InVal, Inc, "ptrincdec"); 1173 } else { 1174 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1175 NextVal = Builder.CreateBitCast(InVal, i8Ty, "tmp"); 1176 NextVal = Builder.CreateGEP(NextVal, Inc, "ptrincdec"); 1177 NextVal = Builder.CreateBitCast(NextVal, InVal->getType()); 1178 } 1179 } else if (InVal->getType()->isIntegerTy(1) && isInc) { 1180 // Bool++ is an interesting case, due to promotion rules, we get: 1181 // Bool++ -> Bool = Bool+1 -> Bool = (int)Bool+1 -> 1182 // Bool = ((int)Bool+1) != 0 1183 // An interesting aspect of this is that increment is always true. 1184 // Decrement does not have this property. 1185 NextVal = llvm::ConstantInt::getTrue(VMContext); 1186 } else if (isa<llvm::IntegerType>(InVal->getType())) { 1187 NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); 1188 1189 if (!ValTy->isSignedIntegerType()) 1190 // Unsigned integer inc is always two's complement. 1191 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1192 else { 1193 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1194 case LangOptions::SOB_Undefined: 1195 NextVal = Builder.CreateNSWAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1196 break; 1197 case LangOptions::SOB_Defined: 1198 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1199 break; 1200 case LangOptions::SOB_Trapping: 1201 BinOpInfo BinOp; 1202 BinOp.LHS = InVal; 1203 BinOp.RHS = NextVal; 1204 BinOp.Ty = E->getType(); 1205 BinOp.Opcode = BO_Add; 1206 BinOp.E = E; 1207 NextVal = EmitOverflowCheckedBinOp(BinOp); 1208 break; 1209 } 1210 } 1211 } else { 1212 // Add the inc/dec to the real part. 1213 if (InVal->getType()->isFloatTy()) 1214 NextVal = 1215 llvm::ConstantFP::get(VMContext, 1216 llvm::APFloat(static_cast<float>(AmountVal))); 1217 else if (InVal->getType()->isDoubleTy()) 1218 NextVal = 1219 llvm::ConstantFP::get(VMContext, 1220 llvm::APFloat(static_cast<double>(AmountVal))); 1221 else { 1222 llvm::APFloat F(static_cast<float>(AmountVal)); 1223 bool ignored; 1224 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, 1225 &ignored); 1226 NextVal = llvm::ConstantFP::get(VMContext, F); 1227 } 1228 NextVal = Builder.CreateFAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1229 } 1230 1231 // Store the updated result through the lvalue. 1232 if (LV.isBitField()) 1233 CGF.EmitStoreThroughBitfieldLValue(RValue::get(NextVal), LV, ValTy, &NextVal); 1234 else 1235 CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV, ValTy); 1236 1237 // If this is a postinc, return the value read from memory, otherwise use the 1238 // updated value. 1239 return isPre ? NextVal : InVal; 1240} 1241 1242 1243 1244Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1245 TestAndClearIgnoreResultAssign(); 1246 // Emit unary minus with EmitSub so we handle overflow cases etc. 1247 BinOpInfo BinOp; 1248 BinOp.RHS = Visit(E->getSubExpr()); 1249 1250 if (BinOp.RHS->getType()->isFPOrFPVectorTy()) 1251 BinOp.LHS = llvm::ConstantFP::getZeroValueForNegation(BinOp.RHS->getType()); 1252 else 1253 BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType()); 1254 BinOp.Ty = E->getType(); 1255 BinOp.Opcode = BO_Sub; 1256 BinOp.E = E; 1257 return EmitSub(BinOp); 1258} 1259 1260Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1261 TestAndClearIgnoreResultAssign(); 1262 Value *Op = Visit(E->getSubExpr()); 1263 return Builder.CreateNot(Op, "neg"); 1264} 1265 1266Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1267 // Compare operand to zero. 1268 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1269 1270 // Invert value. 1271 // TODO: Could dynamically modify easy computations here. For example, if 1272 // the operand is an icmp ne, turn into icmp eq. 1273 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1274 1275 // ZExt result to the expr type. 1276 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1277} 1278 1279Value *ScalarExprEmitter::VisitOffsetOfExpr(OffsetOfExpr *E) { 1280 // Try folding the offsetof to a constant. 1281 Expr::EvalResult EvalResult; 1282 if (E->Evaluate(EvalResult, CGF.getContext())) 1283 return llvm::ConstantInt::get(VMContext, EvalResult.Val.getInt()); 1284 1285 // Loop over the components of the offsetof to compute the value. 1286 unsigned n = E->getNumComponents(); 1287 const llvm::Type* ResultType = ConvertType(E->getType()); 1288 llvm::Value* Result = llvm::Constant::getNullValue(ResultType); 1289 QualType CurrentType = E->getTypeSourceInfo()->getType(); 1290 for (unsigned i = 0; i != n; ++i) { 1291 OffsetOfExpr::OffsetOfNode ON = E->getComponent(i); 1292 llvm::Value *Offset = 0; 1293 switch (ON.getKind()) { 1294 case OffsetOfExpr::OffsetOfNode::Array: { 1295 // Compute the index 1296 Expr *IdxExpr = E->getIndexExpr(ON.getArrayExprIndex()); 1297 llvm::Value* Idx = CGF.EmitScalarExpr(IdxExpr); 1298 bool IdxSigned = IdxExpr->getType()->isSignedIntegerType(); 1299 Idx = Builder.CreateIntCast(Idx, ResultType, IdxSigned, "conv"); 1300 1301 // Save the element type 1302 CurrentType = 1303 CGF.getContext().getAsArrayType(CurrentType)->getElementType(); 1304 1305 // Compute the element size 1306 llvm::Value* ElemSize = llvm::ConstantInt::get(ResultType, 1307 CGF.getContext().getTypeSizeInChars(CurrentType).getQuantity()); 1308 1309 // Multiply out to compute the result 1310 Offset = Builder.CreateMul(Idx, ElemSize); 1311 break; 1312 } 1313 1314 case OffsetOfExpr::OffsetOfNode::Field: { 1315 FieldDecl *MemberDecl = ON.getField(); 1316 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1317 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1318 1319 // Compute the index of the field in its parent. 1320 unsigned i = 0; 1321 // FIXME: It would be nice if we didn't have to loop here! 1322 for (RecordDecl::field_iterator Field = RD->field_begin(), 1323 FieldEnd = RD->field_end(); 1324 Field != FieldEnd; (void)++Field, ++i) { 1325 if (*Field == MemberDecl) 1326 break; 1327 } 1328 assert(i < RL.getFieldCount() && "offsetof field in wrong type"); 1329 1330 // Compute the offset to the field 1331 int64_t OffsetInt = RL.getFieldOffset(i) / 1332 CGF.getContext().getCharWidth(); 1333 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1334 1335 // Save the element type. 1336 CurrentType = MemberDecl->getType(); 1337 break; 1338 } 1339 1340 case OffsetOfExpr::OffsetOfNode::Identifier: 1341 llvm_unreachable("dependent __builtin_offsetof"); 1342 1343 case OffsetOfExpr::OffsetOfNode::Base: { 1344 if (ON.getBase()->isVirtual()) { 1345 CGF.ErrorUnsupported(E, "virtual base in offsetof"); 1346 continue; 1347 } 1348 1349 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1350 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1351 1352 // Save the element type. 1353 CurrentType = ON.getBase()->getType(); 1354 1355 // Compute the offset to the base. 1356 const RecordType *BaseRT = CurrentType->getAs<RecordType>(); 1357 CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl()); 1358 int64_t OffsetInt = RL.getBaseClassOffset(BaseRD) / 1359 CGF.getContext().getCharWidth(); 1360 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1361 break; 1362 } 1363 } 1364 Result = Builder.CreateAdd(Result, Offset); 1365 } 1366 return Result; 1367} 1368 1369/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of 1370/// argument of the sizeof expression as an integer. 1371Value * 1372ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { 1373 QualType TypeToSize = E->getTypeOfArgument(); 1374 if (E->isSizeOf()) { 1375 if (const VariableArrayType *VAT = 1376 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1377 if (E->isArgumentType()) { 1378 // sizeof(type) - make sure to emit the VLA size. 1379 CGF.EmitVLASize(TypeToSize); 1380 } else { 1381 // C99 6.5.3.4p2: If the argument is an expression of type 1382 // VLA, it is evaluated. 1383 CGF.EmitAnyExpr(E->getArgumentExpr()); 1384 } 1385 1386 return CGF.GetVLASize(VAT); 1387 } 1388 } 1389 1390 // If this isn't sizeof(vla), the result must be constant; use the constant 1391 // folding logic so we don't have to duplicate it here. 1392 Expr::EvalResult Result; 1393 E->Evaluate(Result, CGF.getContext()); 1394 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 1395} 1396 1397Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1398 Expr *Op = E->getSubExpr(); 1399 if (Op->getType()->isAnyComplexType()) 1400 return CGF.EmitComplexExpr(Op, false, true, false, true).first; 1401 return Visit(Op); 1402} 1403Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1404 Expr *Op = E->getSubExpr(); 1405 if (Op->getType()->isAnyComplexType()) 1406 return CGF.EmitComplexExpr(Op, true, false, true, false).second; 1407 1408 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1409 // effects are evaluated, but not the actual value. 1410 if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) 1411 CGF.EmitLValue(Op); 1412 else 1413 CGF.EmitScalarExpr(Op, true); 1414 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1415} 1416 1417//===----------------------------------------------------------------------===// 1418// Binary Operators 1419//===----------------------------------------------------------------------===// 1420 1421BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1422 TestAndClearIgnoreResultAssign(); 1423 BinOpInfo Result; 1424 Result.LHS = Visit(E->getLHS()); 1425 Result.RHS = Visit(E->getRHS()); 1426 Result.Ty = E->getType(); 1427 Result.Opcode = E->getOpcode(); 1428 Result.E = E; 1429 return Result; 1430} 1431 1432LValue ScalarExprEmitter::EmitCompoundAssignLValue( 1433 const CompoundAssignOperator *E, 1434 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &), 1435 Value *&Result) { 1436 QualType LHSTy = E->getLHS()->getType(); 1437 BinOpInfo OpInfo; 1438 1439 if (E->getComputationResultType()->isAnyComplexType()) { 1440 // This needs to go through the complex expression emitter, but it's a tad 1441 // complicated to do that... I'm leaving it out for now. (Note that we do 1442 // actually need the imaginary part of the RHS for multiplication and 1443 // division.) 1444 CGF.ErrorUnsupported(E, "complex compound assignment"); 1445 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType())); 1446 return LValue(); 1447 } 1448 1449 // Emit the RHS first. __block variables need to have the rhs evaluated 1450 // first, plus this should improve codegen a little. 1451 OpInfo.RHS = Visit(E->getRHS()); 1452 OpInfo.Ty = E->getComputationResultType(); 1453 OpInfo.Opcode = E->getOpcode(); 1454 OpInfo.E = E; 1455 // Load/convert the LHS. 1456 LValue LHSLV = EmitCheckedLValue(E->getLHS()); 1457 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 1458 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 1459 E->getComputationLHSType()); 1460 1461 // Expand the binary operator. 1462 Result = (this->*Func)(OpInfo); 1463 1464 // Convert the result back to the LHS type. 1465 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 1466 1467 // Store the result value into the LHS lvalue. Bit-fields are handled 1468 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 1469 // 'An assignment expression has the value of the left operand after the 1470 // assignment...'. 1471 if (LHSLV.isBitField()) 1472 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, 1473 &Result); 1474 else 1475 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); 1476 1477 return LHSLV; 1478} 1479 1480Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 1481 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 1482 bool Ignore = TestAndClearIgnoreResultAssign(); 1483 Value *RHS; 1484 LValue LHS = EmitCompoundAssignLValue(E, Func, RHS); 1485 1486 // If the result is clearly ignored, return now. 1487 if (Ignore) 1488 return 0; 1489 1490 // Objective-C property assignment never reloads the value following a store. 1491 if (LHS.isPropertyRef() || LHS.isKVCRef()) 1492 return RHS; 1493 1494 // If the lvalue is non-volatile, return the computed value of the assignment. 1495 if (!LHS.isVolatileQualified()) 1496 return RHS; 1497 1498 // Otherwise, reload the value. 1499 return EmitLoadOfLValue(LHS, E->getType()); 1500} 1501 1502 1503Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 1504 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1505 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 1506 else if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1507 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 1508 else 1509 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 1510} 1511 1512Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 1513 // Rem in C can't be a floating point type: C99 6.5.5p2. 1514 if (Ops.Ty->isUnsignedIntegerType()) 1515 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 1516 else 1517 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 1518} 1519 1520Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 1521 unsigned IID; 1522 unsigned OpID = 0; 1523 1524 switch (Ops.Opcode) { 1525 case BO_Add: 1526 case BO_AddAssign: 1527 OpID = 1; 1528 IID = llvm::Intrinsic::sadd_with_overflow; 1529 break; 1530 case BO_Sub: 1531 case BO_SubAssign: 1532 OpID = 2; 1533 IID = llvm::Intrinsic::ssub_with_overflow; 1534 break; 1535 case BO_Mul: 1536 case BO_MulAssign: 1537 OpID = 3; 1538 IID = llvm::Intrinsic::smul_with_overflow; 1539 break; 1540 default: 1541 assert(false && "Unsupported operation for overflow detection"); 1542 IID = 0; 1543 } 1544 OpID <<= 1; 1545 OpID |= 1; 1546 1547 const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1548 1549 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1); 1550 1551 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1552 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1553 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1554 1555 // Branch in case of overflow. 1556 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); 1557 llvm::BasicBlock *continueBB = CGF.createBasicBlock("nooverflow", CGF.CurFn); 1558 1559 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1560 1561 // Handle overflow with llvm.trap. 1562 // TODO: it would be better to generate one of these blocks per function. 1563 Builder.SetInsertPoint(overflowBB); 1564 llvm::Function *Trap = CGF.CGM.getIntrinsic(llvm::Intrinsic::trap); 1565 Builder.CreateCall(Trap); 1566 Builder.CreateUnreachable(); 1567 1568 // Continue on. 1569 Builder.SetInsertPoint(continueBB); 1570 return result; 1571} 1572 1573Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 1574 if (!Ops.Ty->isAnyPointerType()) { 1575 if (Ops.Ty->hasSignedIntegerRepresentation()) { 1576 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1577 case LangOptions::SOB_Undefined: 1578 return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add"); 1579 case LangOptions::SOB_Defined: 1580 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1581 case LangOptions::SOB_Trapping: 1582 return EmitOverflowCheckedBinOp(Ops); 1583 } 1584 } 1585 1586 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1587 return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add"); 1588 1589 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1590 } 1591 1592 // Must have binary (not unary) expr here. Unary pointer decrement doesn't 1593 // use this path. 1594 const BinaryOperator *BinOp = cast<BinaryOperator>(Ops.E); 1595 1596 if (Ops.Ty->isPointerType() && 1597 Ops.Ty->getAs<PointerType>()->isVariableArrayType()) { 1598 // The amount of the addition needs to account for the VLA size 1599 CGF.ErrorUnsupported(BinOp, "VLA pointer addition"); 1600 } 1601 1602 Value *Ptr, *Idx; 1603 Expr *IdxExp; 1604 const PointerType *PT = BinOp->getLHS()->getType()->getAs<PointerType>(); 1605 const ObjCObjectPointerType *OPT = 1606 BinOp->getLHS()->getType()->getAs<ObjCObjectPointerType>(); 1607 if (PT || OPT) { 1608 Ptr = Ops.LHS; 1609 Idx = Ops.RHS; 1610 IdxExp = BinOp->getRHS(); 1611 } else { // int + pointer 1612 PT = BinOp->getRHS()->getType()->getAs<PointerType>(); 1613 OPT = BinOp->getRHS()->getType()->getAs<ObjCObjectPointerType>(); 1614 assert((PT || OPT) && "Invalid add expr"); 1615 Ptr = Ops.RHS; 1616 Idx = Ops.LHS; 1617 IdxExp = BinOp->getLHS(); 1618 } 1619 1620 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1621 if (Width < CGF.LLVMPointerWidth) { 1622 // Zero or sign extend the pointer value based on whether the index is 1623 // signed or not. 1624 const llvm::Type *IdxType = CGF.IntPtrTy; 1625 if (IdxExp->getType()->isSignedIntegerType()) 1626 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1627 else 1628 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1629 } 1630 const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType(); 1631 // Handle interface types, which are not represented with a concrete type. 1632 if (const ObjCObjectType *OIT = ElementType->getAs<ObjCObjectType>()) { 1633 llvm::Value *InterfaceSize = 1634 llvm::ConstantInt::get(Idx->getType(), 1635 CGF.getContext().getTypeSizeInChars(OIT).getQuantity()); 1636 Idx = Builder.CreateMul(Idx, InterfaceSize); 1637 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1638 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1639 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1640 return Builder.CreateBitCast(Res, Ptr->getType()); 1641 } 1642 1643 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 1644 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 1645 // future proof. 1646 if (ElementType->isVoidType() || ElementType->isFunctionType()) { 1647 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1648 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1649 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1650 return Builder.CreateBitCast(Res, Ptr->getType()); 1651 } 1652 1653 return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr"); 1654} 1655 1656Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 1657 if (!isa<llvm::PointerType>(Ops.LHS->getType())) { 1658 if (Ops.Ty->hasSignedIntegerRepresentation()) { 1659 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1660 case LangOptions::SOB_Undefined: 1661 return Builder.CreateNSWSub(Ops.LHS, Ops.RHS, "sub"); 1662 case LangOptions::SOB_Defined: 1663 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1664 case LangOptions::SOB_Trapping: 1665 return EmitOverflowCheckedBinOp(Ops); 1666 } 1667 } 1668 1669 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1670 return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub"); 1671 1672 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1673 } 1674 1675 // Must have binary (not unary) expr here. Unary pointer increment doesn't 1676 // use this path. 1677 const BinaryOperator *BinOp = cast<BinaryOperator>(Ops.E); 1678 1679 if (BinOp->getLHS()->getType()->isPointerType() && 1680 BinOp->getLHS()->getType()->getAs<PointerType>()->isVariableArrayType()) { 1681 // The amount of the addition needs to account for the VLA size for 1682 // ptr-int 1683 // The amount of the division needs to account for the VLA size for 1684 // ptr-ptr. 1685 CGF.ErrorUnsupported(BinOp, "VLA pointer subtraction"); 1686 } 1687 1688 const QualType LHSType = BinOp->getLHS()->getType(); 1689 const QualType LHSElementType = LHSType->getPointeeType(); 1690 if (!isa<llvm::PointerType>(Ops.RHS->getType())) { 1691 // pointer - int 1692 Value *Idx = Ops.RHS; 1693 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1694 if (Width < CGF.LLVMPointerWidth) { 1695 // Zero or sign extend the pointer value based on whether the index is 1696 // signed or not. 1697 const llvm::Type *IdxType = CGF.IntPtrTy; 1698 if (BinOp->getRHS()->getType()->isSignedIntegerType()) 1699 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1700 else 1701 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1702 } 1703 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); 1704 1705 // Handle interface types, which are not represented with a concrete type. 1706 if (const ObjCObjectType *OIT = LHSElementType->getAs<ObjCObjectType>()) { 1707 llvm::Value *InterfaceSize = 1708 llvm::ConstantInt::get(Idx->getType(), 1709 CGF.getContext(). 1710 getTypeSizeInChars(OIT).getQuantity()); 1711 Idx = Builder.CreateMul(Idx, InterfaceSize); 1712 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1713 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1714 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr"); 1715 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1716 } 1717 1718 // Explicitly handle GNU void* and function pointer arithmetic 1719 // extensions. The GNU void* casts amount to no-ops since our void* type is 1720 // i8*, but this is future proof. 1721 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1722 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1723 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1724 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); 1725 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1726 } 1727 1728 return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr"); 1729 } else { 1730 // pointer - pointer 1731 Value *LHS = Ops.LHS; 1732 Value *RHS = Ops.RHS; 1733 1734 CharUnits ElementSize; 1735 1736 // Handle GCC extension for pointer arithmetic on void* and function pointer 1737 // types. 1738 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1739 ElementSize = CharUnits::One(); 1740 } else { 1741 ElementSize = CGF.getContext().getTypeSizeInChars(LHSElementType); 1742 } 1743 1744 const llvm::Type *ResultType = ConvertType(Ops.Ty); 1745 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 1746 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 1747 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 1748 1749 // Optimize out the shift for element size of 1. 1750 if (ElementSize.isOne()) 1751 return BytesBetween; 1752 1753 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 1754 // pointer difference in C is only defined in the case where both operands 1755 // are pointing to elements of an array. 1756 Value *BytesPerElt = 1757 llvm::ConstantInt::get(ResultType, ElementSize.getQuantity()); 1758 return Builder.CreateExactSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 1759 } 1760} 1761 1762Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 1763 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1764 // RHS to the same size as the LHS. 1765 Value *RHS = Ops.RHS; 1766 if (Ops.LHS->getType() != RHS->getType()) 1767 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1768 1769 if (CGF.CatchUndefined 1770 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1771 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1772 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1773 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1774 llvm::ConstantInt::get(RHS->getType(), Width)), 1775 Cont, CGF.getTrapBB()); 1776 CGF.EmitBlock(Cont); 1777 } 1778 1779 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 1780} 1781 1782Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 1783 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1784 // RHS to the same size as the LHS. 1785 Value *RHS = Ops.RHS; 1786 if (Ops.LHS->getType() != RHS->getType()) 1787 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1788 1789 if (CGF.CatchUndefined 1790 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1791 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1792 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1793 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1794 llvm::ConstantInt::get(RHS->getType(), Width)), 1795 Cont, CGF.getTrapBB()); 1796 CGF.EmitBlock(Cont); 1797 } 1798 1799 if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1800 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 1801 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 1802} 1803 1804Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 1805 unsigned SICmpOpc, unsigned FCmpOpc) { 1806 TestAndClearIgnoreResultAssign(); 1807 Value *Result; 1808 QualType LHSTy = E->getLHS()->getType(); 1809 if (const MemberPointerType *MPT = LHSTy->getAs<MemberPointerType>()) { 1810 assert(E->getOpcode() == BO_EQ || 1811 E->getOpcode() == BO_NE); 1812 Value *LHS = CGF.EmitScalarExpr(E->getLHS()); 1813 Value *RHS = CGF.EmitScalarExpr(E->getRHS()); 1814 Result = CGF.CGM.getCXXABI().EmitMemberPointerComparison( 1815 CGF, LHS, RHS, MPT, E->getOpcode() == BO_NE); 1816 } else if (!LHSTy->isAnyComplexType()) { 1817 Value *LHS = Visit(E->getLHS()); 1818 Value *RHS = Visit(E->getRHS()); 1819 1820 if (LHS->getType()->isFPOrFPVectorTy()) { 1821 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 1822 LHS, RHS, "cmp"); 1823 } else if (LHSTy->hasSignedIntegerRepresentation()) { 1824 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 1825 LHS, RHS, "cmp"); 1826 } else { 1827 // Unsigned integers and pointers. 1828 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1829 LHS, RHS, "cmp"); 1830 } 1831 1832 // If this is a vector comparison, sign extend the result to the appropriate 1833 // vector integer type and return it (don't convert to bool). 1834 if (LHSTy->isVectorType()) 1835 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 1836 1837 } else { 1838 // Complex Comparison: can only be an equality comparison. 1839 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 1840 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 1841 1842 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 1843 1844 Value *ResultR, *ResultI; 1845 if (CETy->isRealFloatingType()) { 1846 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1847 LHS.first, RHS.first, "cmp.r"); 1848 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1849 LHS.second, RHS.second, "cmp.i"); 1850 } else { 1851 // Complex comparisons can only be equality comparisons. As such, signed 1852 // and unsigned opcodes are the same. 1853 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1854 LHS.first, RHS.first, "cmp.r"); 1855 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1856 LHS.second, RHS.second, "cmp.i"); 1857 } 1858 1859 if (E->getOpcode() == BO_EQ) { 1860 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 1861 } else { 1862 assert(E->getOpcode() == BO_NE && 1863 "Complex comparison other than == or != ?"); 1864 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 1865 } 1866 } 1867 1868 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 1869} 1870 1871Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 1872 bool Ignore = TestAndClearIgnoreResultAssign(); 1873 1874 // __block variables need to have the rhs evaluated first, plus this should 1875 // improve codegen just a little. 1876 Value *RHS = Visit(E->getRHS()); 1877 LValue LHS = EmitCheckedLValue(E->getLHS()); 1878 1879 // Store the value into the LHS. Bit-fields are handled specially 1880 // because the result is altered by the store, i.e., [C99 6.5.16p1] 1881 // 'An assignment expression has the value of the left operand after 1882 // the assignment...'. 1883 if (LHS.isBitField()) 1884 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), 1885 &RHS); 1886 else 1887 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 1888 1889 // If the result is clearly ignored, return now. 1890 if (Ignore) 1891 return 0; 1892 1893 // Objective-C property assignment never reloads the value following a store. 1894 if (LHS.isPropertyRef() || LHS.isKVCRef()) 1895 return RHS; 1896 1897 // If the lvalue is non-volatile, return the computed value of the assignment. 1898 if (!LHS.isVolatileQualified()) 1899 return RHS; 1900 1901 // Otherwise, reload the value. 1902 return EmitLoadOfLValue(LHS, E->getType()); 1903} 1904 1905Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 1906 const llvm::Type *ResTy = ConvertType(E->getType()); 1907 1908 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 1909 // If we have 1 && X, just emit X without inserting the control flow. 1910 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1911 if (Cond == 1) { // If we have 1 && X, just emit X. 1912 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1913 // ZExt result to int or bool. 1914 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 1915 } 1916 1917 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 1918 if (!CGF.ContainsLabel(E->getRHS())) 1919 return llvm::Constant::getNullValue(ResTy); 1920 } 1921 1922 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 1923 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 1924 1925 // Branch on the LHS first. If it is false, go to the failure (cont) block. 1926 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 1927 1928 // Any edges into the ContBlock are now from an (indeterminate number of) 1929 // edges from this first condition. All of these values will be false. Start 1930 // setting up the PHI node in the Cont Block for this. 1931 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1932 "", ContBlock); 1933 PN->reserveOperandSpace(2); // Normal case, two inputs. 1934 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1935 PI != PE; ++PI) 1936 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 1937 1938 CGF.BeginConditionalBranch(); 1939 CGF.EmitBlock(RHSBlock); 1940 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1941 CGF.EndConditionalBranch(); 1942 1943 // Reaquire the RHS block, as there may be subblocks inserted. 1944 RHSBlock = Builder.GetInsertBlock(); 1945 1946 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1947 // into the phi node for the edge with the value of RHSCond. 1948 CGF.EmitBlock(ContBlock); 1949 PN->addIncoming(RHSCond, RHSBlock); 1950 1951 // ZExt result to int. 1952 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); 1953} 1954 1955Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 1956 const llvm::Type *ResTy = ConvertType(E->getType()); 1957 1958 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 1959 // If we have 0 || X, just emit X without inserting the control flow. 1960 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1961 if (Cond == -1) { // If we have 0 || X, just emit X. 1962 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1963 // ZExt result to int or bool. 1964 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 1965 } 1966 1967 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 1968 if (!CGF.ContainsLabel(E->getRHS())) 1969 return llvm::ConstantInt::get(ResTy, 1); 1970 } 1971 1972 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 1973 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 1974 1975 // Branch on the LHS first. If it is true, go to the success (cont) block. 1976 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 1977 1978 // Any edges into the ContBlock are now from an (indeterminate number of) 1979 // edges from this first condition. All of these values will be true. Start 1980 // setting up the PHI node in the Cont Block for this. 1981 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1982 "", ContBlock); 1983 PN->reserveOperandSpace(2); // Normal case, two inputs. 1984 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1985 PI != PE; ++PI) 1986 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 1987 1988 CGF.BeginConditionalBranch(); 1989 1990 // Emit the RHS condition as a bool value. 1991 CGF.EmitBlock(RHSBlock); 1992 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1993 1994 CGF.EndConditionalBranch(); 1995 1996 // Reaquire the RHS block, as there may be subblocks inserted. 1997 RHSBlock = Builder.GetInsertBlock(); 1998 1999 // Emit an unconditional branch from this block to ContBlock. Insert an entry 2000 // into the phi node for the edge with the value of RHSCond. 2001 CGF.EmitBlock(ContBlock); 2002 PN->addIncoming(RHSCond, RHSBlock); 2003 2004 // ZExt result to int. 2005 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 2006} 2007 2008Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 2009 CGF.EmitStmt(E->getLHS()); 2010 CGF.EnsureInsertPoint(); 2011 return Visit(E->getRHS()); 2012} 2013 2014//===----------------------------------------------------------------------===// 2015// Other Operators 2016//===----------------------------------------------------------------------===// 2017 2018/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 2019/// expression is cheap enough and side-effect-free enough to evaluate 2020/// unconditionally instead of conditionally. This is used to convert control 2021/// flow into selects in some cases. 2022static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 2023 CodeGenFunction &CGF) { 2024 if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) 2025 return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr(), CGF); 2026 2027 // TODO: Allow anything we can constant fold to an integer or fp constant. 2028 if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || 2029 isa<FloatingLiteral>(E)) 2030 return true; 2031 2032 // Non-volatile automatic variables too, to get "cond ? X : Y" where 2033 // X and Y are local variables. 2034 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 2035 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 2036 if (VD->hasLocalStorage() && !(CGF.getContext() 2037 .getCanonicalType(VD->getType()) 2038 .isVolatileQualified())) 2039 return true; 2040 2041 return false; 2042} 2043 2044 2045Value *ScalarExprEmitter:: 2046VisitConditionalOperator(const ConditionalOperator *E) { 2047 TestAndClearIgnoreResultAssign(); 2048 // If the condition constant folds and can be elided, try to avoid emitting 2049 // the condition and the dead arm. 2050 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ 2051 Expr *Live = E->getLHS(), *Dead = E->getRHS(); 2052 if (Cond == -1) 2053 std::swap(Live, Dead); 2054 2055 // If the dead side doesn't have labels we need, and if the Live side isn't 2056 // the gnu missing ?: extension (which we could handle, but don't bother 2057 // to), just emit the Live part. 2058 if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part 2059 Live) // Live part isn't missing. 2060 return Visit(Live); 2061 } 2062 2063 2064 // If this is a really simple expression (like x ? 4 : 5), emit this as a 2065 // select instead of as control flow. We can only do this if it is cheap and 2066 // safe to evaluate the LHS and RHS unconditionally. 2067 if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS(), 2068 CGF) && 2069 isCheapEnoughToEvaluateUnconditionally(E->getRHS(), CGF)) { 2070 llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); 2071 llvm::Value *LHS = Visit(E->getLHS()); 2072 llvm::Value *RHS = Visit(E->getRHS()); 2073 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 2074 } 2075 2076 if (!E->getLHS() && CGF.getContext().getLangOptions().CPlusPlus) { 2077 // Does not support GNU missing condition extension in C++ yet (see #7726) 2078 CGF.ErrorUnsupported(E, "conditional operator with missing LHS"); 2079 return llvm::UndefValue::get(ConvertType(E->getType())); 2080 } 2081 2082 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 2083 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 2084 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 2085 Value *CondVal = 0; 2086 2087 // If we don't have the GNU missing condition extension, emit a branch on bool 2088 // the normal way. 2089 if (E->getLHS()) { 2090 // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for 2091 // the branch on bool. 2092 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); 2093 } else { 2094 // Otherwise, for the ?: extension, evaluate the conditional and then 2095 // convert it to bool the hard way. We do this explicitly because we need 2096 // the unconverted value for the missing middle value of the ?:. 2097 CondVal = CGF.EmitScalarExpr(E->getCond()); 2098 2099 // In some cases, EmitScalarConversion will delete the "CondVal" expression 2100 // if there are no extra uses (an optimization). Inhibit this by making an 2101 // extra dead use, because we're going to add a use of CondVal later. We 2102 // don't use the builder for this, because we don't want it to get optimized 2103 // away. This leaves dead code, but the ?: extension isn't common. 2104 new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", 2105 Builder.GetInsertBlock()); 2106 2107 Value *CondBoolVal = 2108 CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 2109 CGF.getContext().BoolTy); 2110 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 2111 } 2112 2113 CGF.BeginConditionalBranch(); 2114 CGF.EmitBlock(LHSBlock); 2115 2116 // Handle the GNU extension for missing LHS. 2117 Value *LHS; 2118 if (E->getLHS()) 2119 LHS = Visit(E->getLHS()); 2120 else // Perform promotions, to handle cases like "short ?: int" 2121 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); 2122 2123 CGF.EndConditionalBranch(); 2124 LHSBlock = Builder.GetInsertBlock(); 2125 CGF.EmitBranch(ContBlock); 2126 2127 CGF.BeginConditionalBranch(); 2128 CGF.EmitBlock(RHSBlock); 2129 2130 Value *RHS = Visit(E->getRHS()); 2131 CGF.EndConditionalBranch(); 2132 RHSBlock = Builder.GetInsertBlock(); 2133 CGF.EmitBranch(ContBlock); 2134 2135 CGF.EmitBlock(ContBlock); 2136 2137 // If the LHS or RHS is a throw expression, it will be legitimately null. 2138 if (!LHS) 2139 return RHS; 2140 if (!RHS) 2141 return LHS; 2142 2143 // Create a PHI node for the real part. 2144 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 2145 PN->reserveOperandSpace(2); 2146 PN->addIncoming(LHS, LHSBlock); 2147 PN->addIncoming(RHS, RHSBlock); 2148 return PN; 2149} 2150 2151Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 2152 return Visit(E->getChosenSubExpr(CGF.getContext())); 2153} 2154 2155Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 2156 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 2157 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 2158 2159 // If EmitVAArg fails, we fall back to the LLVM instruction. 2160 if (!ArgPtr) 2161 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 2162 2163 // FIXME Volatility. 2164 return Builder.CreateLoad(ArgPtr); 2165} 2166 2167Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { 2168 return CGF.BuildBlockLiteralTmp(BE); 2169} 2170 2171//===----------------------------------------------------------------------===// 2172// Entry Point into this File 2173//===----------------------------------------------------------------------===// 2174 2175/// EmitScalarExpr - Emit the computation of the specified expression of scalar 2176/// type, ignoring the result. 2177Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 2178 assert(E && !hasAggregateLLVMType(E->getType()) && 2179 "Invalid scalar expression to emit"); 2180 2181 return ScalarExprEmitter(*this, IgnoreResultAssign) 2182 .Visit(const_cast<Expr*>(E)); 2183} 2184 2185/// EmitScalarConversion - Emit a conversion from the specified type to the 2186/// specified destination type, both of which are LLVM scalar types. 2187Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 2188 QualType DstTy) { 2189 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 2190 "Invalid scalar expression to emit"); 2191 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 2192} 2193 2194/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 2195/// type to the specified destination type, where the destination type is an 2196/// LLVM scalar type. 2197Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 2198 QualType SrcTy, 2199 QualType DstTy) { 2200 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 2201 "Invalid complex -> scalar conversion"); 2202 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 2203 DstTy); 2204} 2205 2206 2207llvm::Value *CodeGenFunction:: 2208EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 2209 bool isInc, bool isPre) { 2210 return ScalarExprEmitter(*this).EmitScalarPrePostIncDec(E, LV, isInc, isPre); 2211} 2212 2213LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) { 2214 llvm::Value *V; 2215 // object->isa or (*object).isa 2216 // Generate code as for: *(Class*)object 2217 // build Class* type 2218 const llvm::Type *ClassPtrTy = ConvertType(E->getType()); 2219 2220 Expr *BaseExpr = E->getBase(); 2221 if (BaseExpr->isLvalue(getContext()) != Expr::LV_Valid) { 2222 V = CreateTempAlloca(ClassPtrTy, "resval"); 2223 llvm::Value *Src = EmitScalarExpr(BaseExpr); 2224 Builder.CreateStore(Src, V); 2225 V = ScalarExprEmitter(*this).EmitLoadOfLValue( 2226 MakeAddrLValue(V, E->getType()), E->getType()); 2227 } else { 2228 if (E->isArrow()) 2229 V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr); 2230 else 2231 V = EmitLValue(BaseExpr).getAddress(); 2232 } 2233 2234 // build Class* type 2235 ClassPtrTy = ClassPtrTy->getPointerTo(); 2236 V = Builder.CreateBitCast(V, ClassPtrTy); 2237 return MakeAddrLValue(V, E->getType()); 2238} 2239 2240 2241LValue CodeGenFunction::EmitCompoundAssignOperatorLValue( 2242 const CompoundAssignOperator *E) { 2243 ScalarExprEmitter Scalar(*this); 2244 Value *Result = 0; 2245 switch (E->getOpcode()) { 2246#define COMPOUND_OP(Op) \ 2247 case BO_##Op##Assign: \ 2248 return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \ 2249 Result) 2250 COMPOUND_OP(Mul); 2251 COMPOUND_OP(Div); 2252 COMPOUND_OP(Rem); 2253 COMPOUND_OP(Add); 2254 COMPOUND_OP(Sub); 2255 COMPOUND_OP(Shl); 2256 COMPOUND_OP(Shr); 2257 COMPOUND_OP(And); 2258 COMPOUND_OP(Xor); 2259 COMPOUND_OP(Or); 2260#undef COMPOUND_OP 2261 2262 case BO_PtrMemD: 2263 case BO_PtrMemI: 2264 case BO_Mul: 2265 case BO_Div: 2266 case BO_Rem: 2267 case BO_Add: 2268 case BO_Sub: 2269 case BO_Shl: 2270 case BO_Shr: 2271 case BO_LT: 2272 case BO_GT: 2273 case BO_LE: 2274 case BO_GE: 2275 case BO_EQ: 2276 case BO_NE: 2277 case BO_And: 2278 case BO_Xor: 2279 case BO_Or: 2280 case BO_LAnd: 2281 case BO_LOr: 2282 case BO_Assign: 2283 case BO_Comma: 2284 assert(false && "Not valid compound assignment operators"); 2285 break; 2286 } 2287 2288 llvm_unreachable("Unhandled compound assignment operator"); 2289} 2290