CGExprScalar.cpp revision e9776247577715ad3a19461769a3488a445a8cbd
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 "CodeGenModule.h" 16#include "clang/AST/ASTContext.h" 17#include "clang/AST/DeclObjC.h" 18#include "clang/AST/RecordLayout.h" 19#include "clang/AST/StmtVisitor.h" 20#include "clang/Basic/TargetInfo.h" 21#include "llvm/Constants.h" 22#include "llvm/Function.h" 23#include "llvm/GlobalVariable.h" 24#include "llvm/Intrinsics.h" 25#include "llvm/Module.h" 26#include "llvm/Support/Compiler.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 const BinaryOperator *E; 44}; 45 46namespace { 47class VISIBILITY_HIDDEN ScalarExprEmitter 48 : public StmtVisitor<ScalarExprEmitter, Value*> { 49 CodeGenFunction &CGF; 50 CGBuilderTy &Builder; 51 bool IgnoreResultAssign; 52 llvm::LLVMContext &VMContext; 53public: 54 55 ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false) 56 : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira), 57 VMContext(cgf.getLLVMContext()) { 58 } 59 60 //===--------------------------------------------------------------------===// 61 // Utilities 62 //===--------------------------------------------------------------------===// 63 64 bool TestAndClearIgnoreResultAssign() { 65 bool I = IgnoreResultAssign; 66 IgnoreResultAssign = false; 67 return I; 68 } 69 70 const llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); } 71 LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); } 72 73 Value *EmitLoadOfLValue(LValue LV, QualType T) { 74 return CGF.EmitLoadOfLValue(LV, T).getScalarVal(); 75 } 76 77 /// EmitLoadOfLValue - Given an expression with complex type that represents a 78 /// value l-value, this method emits the address of the l-value, then loads 79 /// and returns the result. 80 Value *EmitLoadOfLValue(const Expr *E) { 81 return EmitLoadOfLValue(EmitLValue(E), E->getType()); 82 } 83 84 /// EmitConversionToBool - Convert the specified expression value to a 85 /// boolean (i1) truth value. This is equivalent to "Val != 0". 86 Value *EmitConversionToBool(Value *Src, QualType DstTy); 87 88 /// EmitScalarConversion - Emit a conversion from the specified type to the 89 /// specified destination type, both of which are LLVM scalar types. 90 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); 91 92 /// EmitComplexToScalarConversion - Emit a conversion from the specified 93 /// complex type to the specified destination type, where the destination 94 /// type is an LLVM scalar type. 95 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 96 QualType SrcTy, QualType DstTy); 97 98 //===--------------------------------------------------------------------===// 99 // Visitor Methods 100 //===--------------------------------------------------------------------===// 101 102 Value *VisitStmt(Stmt *S) { 103 S->dump(CGF.getContext().getSourceManager()); 104 assert(0 && "Stmt can't have complex result type!"); 105 return 0; 106 } 107 Value *VisitExpr(Expr *S); 108 Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); } 109 110 // Leaves. 111 Value *VisitIntegerLiteral(const IntegerLiteral *E) { 112 return llvm::ConstantInt::get(VMContext, E->getValue()); 113 } 114 Value *VisitFloatingLiteral(const FloatingLiteral *E) { 115 return llvm::ConstantFP::get(VMContext, E->getValue()); 116 } 117 Value *VisitCharacterLiteral(const CharacterLiteral *E) { 118 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 119 } 120 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 121 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 122 } 123 Value *VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) { 124 return llvm::Constant::getNullValue(ConvertType(E->getType())); 125 } 126 Value *VisitGNUNullExpr(const GNUNullExpr *E) { 127 return llvm::Constant::getNullValue(ConvertType(E->getType())); 128 } 129 Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { 130 return llvm::ConstantInt::get(ConvertType(E->getType()), 131 CGF.getContext().typesAreCompatible( 132 E->getArgType1(), E->getArgType2())); 133 } 134 Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); 135 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 136 llvm::Value *V = 137 llvm::ConstantInt::get(llvm::Type::getInt32Ty(CGF.getLLVMContext()), 138 CGF.GetIDForAddrOfLabel(E->getLabel())); 139 140 return Builder.CreateIntToPtr(V, ConvertType(E->getType())); 141 } 142 143 // l-values. 144 Value *VisitDeclRefExpr(DeclRefExpr *E) { 145 if (const EnumConstantDecl *EC = dyn_cast<EnumConstantDecl>(E->getDecl())) 146 return llvm::ConstantInt::get(VMContext, EC->getInitVal()); 147 return EmitLoadOfLValue(E); 148 } 149 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 150 return CGF.EmitObjCSelectorExpr(E); 151 } 152 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 153 return CGF.EmitObjCProtocolExpr(E); 154 } 155 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 156 return EmitLoadOfLValue(E); 157 } 158 Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { 159 return EmitLoadOfLValue(E); 160 } 161 Value *VisitObjCImplicitSetterGetterRefExpr( 162 ObjCImplicitSetterGetterRefExpr *E) { 163 return EmitLoadOfLValue(E); 164 } 165 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 166 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 167 } 168 169 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 170 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 171 Value *VisitMemberExpr(Expr *E) { return EmitLoadOfLValue(E); } 172 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 173 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 174 return EmitLoadOfLValue(E); 175 } 176 Value *VisitStringLiteral(Expr *E) { return EmitLValue(E).getAddress(); } 177 Value *VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { 178 return EmitLValue(E).getAddress(); 179 } 180 181 Value *VisitPredefinedExpr(Expr *E) { return EmitLValue(E).getAddress(); } 182 183 Value *VisitInitListExpr(InitListExpr *E) { 184 bool Ignore = TestAndClearIgnoreResultAssign(); 185 (void)Ignore; 186 assert (Ignore == false && "init list ignored"); 187 unsigned NumInitElements = E->getNumInits(); 188 189 if (E->hadArrayRangeDesignator()) { 190 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 191 } 192 193 const llvm::VectorType *VType = 194 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 195 196 // We have a scalar in braces. Just use the first element. 197 if (!VType) 198 return Visit(E->getInit(0)); 199 200 unsigned NumVectorElements = VType->getNumElements(); 201 const llvm::Type *ElementType = VType->getElementType(); 202 203 // Emit individual vector element stores. 204 llvm::Value *V = llvm::UndefValue::get(VType); 205 206 // Emit initializers 207 unsigned i; 208 for (i = 0; i < NumInitElements; ++i) { 209 Value *NewV = Visit(E->getInit(i)); 210 Value *Idx = 211 llvm::ConstantInt::get(llvm::Type::getInt32Ty(CGF.getLLVMContext()), i); 212 V = Builder.CreateInsertElement(V, NewV, Idx); 213 } 214 215 // Emit remaining default initializers 216 for (/* Do not initialize i*/; i < NumVectorElements; ++i) { 217 Value *Idx = 218 llvm::ConstantInt::get(llvm::Type::getInt32Ty(CGF.getLLVMContext()), i); 219 llvm::Value *NewV = llvm::Constant::getNullValue(ElementType); 220 V = Builder.CreateInsertElement(V, NewV, Idx); 221 } 222 223 return V; 224 } 225 226 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { 227 return llvm::Constant::getNullValue(ConvertType(E->getType())); 228 } 229 Value *VisitImplicitCastExpr(const ImplicitCastExpr *E); 230 Value *VisitCastExpr(const CastExpr *E) { 231 // Make sure to evaluate VLA bounds now so that we have them for later. 232 if (E->getType()->isVariablyModifiedType()) 233 CGF.EmitVLASize(E->getType()); 234 235 return EmitCastExpr(E->getSubExpr(), E->getType(), E->getCastKind()); 236 } 237 Value *EmitCastExpr(const Expr *E, QualType T, CastExpr::CastKind Kind); 238 239 Value *VisitCallExpr(const CallExpr *E) { 240 if (E->getCallReturnType()->isReferenceType()) 241 return EmitLoadOfLValue(E); 242 243 return CGF.EmitCallExpr(E).getScalarVal(); 244 } 245 246 Value *VisitStmtExpr(const StmtExpr *E); 247 248 Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E); 249 250 // Unary Operators. 251 Value *VisitPrePostIncDec(const UnaryOperator *E, bool isInc, bool isPre); 252 Value *VisitUnaryPostDec(const UnaryOperator *E) { 253 return VisitPrePostIncDec(E, false, false); 254 } 255 Value *VisitUnaryPostInc(const UnaryOperator *E) { 256 return VisitPrePostIncDec(E, true, false); 257 } 258 Value *VisitUnaryPreDec(const UnaryOperator *E) { 259 return VisitPrePostIncDec(E, false, true); 260 } 261 Value *VisitUnaryPreInc(const UnaryOperator *E) { 262 return VisitPrePostIncDec(E, true, true); 263 } 264 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 265 return EmitLValue(E->getSubExpr()).getAddress(); 266 } 267 Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } 268 Value *VisitUnaryPlus(const UnaryOperator *E) { 269 // This differs from gcc, though, most likely due to a bug in gcc. 270 TestAndClearIgnoreResultAssign(); 271 return Visit(E->getSubExpr()); 272 } 273 Value *VisitUnaryMinus (const UnaryOperator *E); 274 Value *VisitUnaryNot (const UnaryOperator *E); 275 Value *VisitUnaryLNot (const UnaryOperator *E); 276 Value *VisitUnaryReal (const UnaryOperator *E); 277 Value *VisitUnaryImag (const UnaryOperator *E); 278 Value *VisitUnaryExtension(const UnaryOperator *E) { 279 return Visit(E->getSubExpr()); 280 } 281 Value *VisitUnaryOffsetOf(const UnaryOperator *E); 282 283 // C++ 284 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 285 return Visit(DAE->getExpr()); 286 } 287 Value *VisitCXXThisExpr(CXXThisExpr *TE) { 288 return CGF.LoadCXXThis(); 289 } 290 291 Value *VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) { 292 return CGF.EmitCXXExprWithTemporaries(E).getScalarVal(); 293 } 294 Value *VisitCXXNewExpr(const CXXNewExpr *E) { 295 return CGF.EmitCXXNewExpr(E); 296 } 297 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { 298 CGF.EmitCXXDeleteExpr(E); 299 return 0; 300 } 301 302 // Binary Operators. 303 Value *EmitMul(const BinOpInfo &Ops) { 304 if (CGF.getContext().getLangOptions().OverflowChecking 305 && Ops.Ty->isSignedIntegerType()) 306 return EmitOverflowCheckedBinOp(Ops); 307 if (Ops.LHS->getType()->isFPOrFPVector()) 308 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 309 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 310 } 311 /// Create a binary op that checks for overflow. 312 /// Currently only supports +, - and *. 313 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 314 Value *EmitDiv(const BinOpInfo &Ops); 315 Value *EmitRem(const BinOpInfo &Ops); 316 Value *EmitAdd(const BinOpInfo &Ops); 317 Value *EmitSub(const BinOpInfo &Ops); 318 Value *EmitShl(const BinOpInfo &Ops); 319 Value *EmitShr(const BinOpInfo &Ops); 320 Value *EmitAnd(const BinOpInfo &Ops) { 321 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 322 } 323 Value *EmitXor(const BinOpInfo &Ops) { 324 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 325 } 326 Value *EmitOr (const BinOpInfo &Ops) { 327 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 328 } 329 330 BinOpInfo EmitBinOps(const BinaryOperator *E); 331 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 332 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 333 334 // Binary operators and binary compound assignment operators. 335#define HANDLEBINOP(OP) \ 336 Value *VisitBin ## OP(const BinaryOperator *E) { \ 337 return Emit ## OP(EmitBinOps(E)); \ 338 } \ 339 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 340 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 341 } 342 HANDLEBINOP(Mul); 343 HANDLEBINOP(Div); 344 HANDLEBINOP(Rem); 345 HANDLEBINOP(Add); 346 HANDLEBINOP(Sub); 347 HANDLEBINOP(Shl); 348 HANDLEBINOP(Shr); 349 HANDLEBINOP(And); 350 HANDLEBINOP(Xor); 351 HANDLEBINOP(Or); 352#undef HANDLEBINOP 353 354 // Comparisons. 355 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 356 unsigned SICmpOpc, unsigned FCmpOpc); 357#define VISITCOMP(CODE, UI, SI, FP) \ 358 Value *VisitBin##CODE(const BinaryOperator *E) { \ 359 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 360 llvm::FCmpInst::FP); } 361 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT); 362 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT); 363 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE); 364 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE); 365 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ); 366 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE); 367#undef VISITCOMP 368 369 Value *VisitBinAssign (const BinaryOperator *E); 370 371 Value *VisitBinLAnd (const BinaryOperator *E); 372 Value *VisitBinLOr (const BinaryOperator *E); 373 Value *VisitBinComma (const BinaryOperator *E); 374 375 // Other Operators. 376 Value *VisitBlockExpr(const BlockExpr *BE); 377 Value *VisitConditionalOperator(const ConditionalOperator *CO); 378 Value *VisitChooseExpr(ChooseExpr *CE); 379 Value *VisitVAArgExpr(VAArgExpr *VE); 380 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 381 return CGF.EmitObjCStringLiteral(E); 382 } 383}; 384} // end anonymous namespace. 385 386//===----------------------------------------------------------------------===// 387// Utilities 388//===----------------------------------------------------------------------===// 389 390/// EmitConversionToBool - Convert the specified expression value to a 391/// boolean (i1) truth value. This is equivalent to "Val != 0". 392Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 393 assert(SrcType->isCanonical() && "EmitScalarConversion strips typedefs"); 394 395 if (SrcType->isRealFloatingType()) { 396 // Compare against 0.0 for fp scalars. 397 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 398 return Builder.CreateFCmpUNE(Src, Zero, "tobool"); 399 } 400 401 if (SrcType->isMemberPointerType()) { 402 // FIXME: This is ABI specific. 403 404 // Compare against -1. 405 llvm::Value *NegativeOne = llvm::Constant::getAllOnesValue(Src->getType()); 406 return Builder.CreateICmpNE(Src, NegativeOne, "tobool"); 407 } 408 409 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 410 "Unknown scalar type to convert"); 411 412 // Because of the type rules of C, we often end up computing a logical value, 413 // then zero extending it to int, then wanting it as a logical value again. 414 // Optimize this common case. 415 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) { 416 if (ZI->getOperand(0)->getType() == 417 llvm::Type::getInt1Ty(CGF.getLLVMContext())) { 418 Value *Result = ZI->getOperand(0); 419 // If there aren't any more uses, zap the instruction to save space. 420 // Note that there can be more uses, for example if this 421 // is the result of an assignment. 422 if (ZI->use_empty()) 423 ZI->eraseFromParent(); 424 return Result; 425 } 426 } 427 428 // Compare against an integer or pointer null. 429 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 430 return Builder.CreateICmpNE(Src, Zero, "tobool"); 431} 432 433/// EmitScalarConversion - Emit a conversion from the specified type to the 434/// specified destination type, both of which are LLVM scalar types. 435Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 436 QualType DstType) { 437 SrcType = CGF.getContext().getCanonicalType(SrcType); 438 DstType = CGF.getContext().getCanonicalType(DstType); 439 if (SrcType == DstType) return Src; 440 441 if (DstType->isVoidType()) return 0; 442 443 llvm::LLVMContext &VMContext = CGF.getLLVMContext(); 444 445 // Handle conversions to bool first, they are special: comparisons against 0. 446 if (DstType->isBooleanType()) 447 return EmitConversionToBool(Src, SrcType); 448 449 const llvm::Type *DstTy = ConvertType(DstType); 450 451 // Ignore conversions like int -> uint. 452 if (Src->getType() == DstTy) 453 return Src; 454 455 // Handle pointer conversions next: pointers can only be converted 456 // to/from other pointers and integers. Check for pointer types in 457 // terms of LLVM, as some native types (like Obj-C id) may map to a 458 // pointer type. 459 if (isa<llvm::PointerType>(DstTy)) { 460 // The source value may be an integer, or a pointer. 461 if (isa<llvm::PointerType>(Src->getType())) { 462 // Some heavy lifting for derived to base conversion. 463 if (const CXXRecordDecl *ClassDecl = 464 SrcType->getCXXRecordDeclForPointerType()) 465 if (const CXXRecordDecl *BaseClassDecl = 466 DstType->getCXXRecordDeclForPointerType()) 467 Src = CGF.AddressCXXOfBaseClass(Src, ClassDecl, BaseClassDecl); 468 return Builder.CreateBitCast(Src, DstTy, "conv"); 469 } 470 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 471 // First, convert to the correct width so that we control the kind of 472 // extension. 473 const llvm::Type *MiddleTy = 474 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 475 bool InputSigned = SrcType->isSignedIntegerType(); 476 llvm::Value* IntResult = 477 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 478 // Then, cast to pointer. 479 return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); 480 } 481 482 if (isa<llvm::PointerType>(Src->getType())) { 483 // Must be an ptr to int cast. 484 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 485 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 486 } 487 488 // A scalar can be splatted to an extended vector of the same element type 489 if (DstType->isExtVectorType() && !SrcType->isVectorType()) { 490 // Cast the scalar to element type 491 QualType EltTy = DstType->getAsExtVectorType()->getElementType(); 492 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 493 494 // Insert the element in element zero of an undef vector 495 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 496 llvm::Value *Idx = 497 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 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( 505 llvm::Type::getInt32Ty(VMContext), 0)); 506 507 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 508 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 509 return Yay; 510 } 511 512 // Allow bitcast from vector to integer/fp of the same size. 513 if (isa<llvm::VectorType>(Src->getType()) || 514 isa<llvm::VectorType>(DstTy)) 515 return Builder.CreateBitCast(Src, DstTy, "conv"); 516 517 // Finally, we have the arithmetic types: real int/float. 518 if (isa<llvm::IntegerType>(Src->getType())) { 519 bool InputSigned = SrcType->isSignedIntegerType(); 520 if (isa<llvm::IntegerType>(DstTy)) 521 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 522 else if (InputSigned) 523 return Builder.CreateSIToFP(Src, DstTy, "conv"); 524 else 525 return Builder.CreateUIToFP(Src, DstTy, "conv"); 526 } 527 528 assert(Src->getType()->isFloatingPoint() && "Unknown real conversion"); 529 if (isa<llvm::IntegerType>(DstTy)) { 530 if (DstType->isSignedIntegerType()) 531 return Builder.CreateFPToSI(Src, DstTy, "conv"); 532 else 533 return Builder.CreateFPToUI(Src, DstTy, "conv"); 534 } 535 536 assert(DstTy->isFloatingPoint() && "Unknown real conversion"); 537 if (DstTy->getTypeID() < Src->getType()->getTypeID()) 538 return Builder.CreateFPTrunc(Src, DstTy, "conv"); 539 else 540 return Builder.CreateFPExt(Src, DstTy, "conv"); 541} 542 543/// EmitComplexToScalarConversion - Emit a conversion from the specified 544/// complex type to the specified destination type, where the destination 545/// type is an LLVM scalar type. 546Value *ScalarExprEmitter:: 547EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 548 QualType SrcTy, QualType DstTy) { 549 // Get the source element type. 550 SrcTy = SrcTy->getAsComplexType()->getElementType(); 551 552 // Handle conversions to bool first, they are special: comparisons against 0. 553 if (DstTy->isBooleanType()) { 554 // Complex != 0 -> (Real != 0) | (Imag != 0) 555 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 556 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 557 return Builder.CreateOr(Src.first, Src.second, "tobool"); 558 } 559 560 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 561 // the imaginary part of the complex value is discarded and the value of the 562 // real part is converted according to the conversion rules for the 563 // corresponding real type. 564 return EmitScalarConversion(Src.first, SrcTy, DstTy); 565} 566 567 568//===----------------------------------------------------------------------===// 569// Visitor Methods 570//===----------------------------------------------------------------------===// 571 572Value *ScalarExprEmitter::VisitExpr(Expr *E) { 573 CGF.ErrorUnsupported(E, "scalar expression"); 574 if (E->getType()->isVoidType()) 575 return 0; 576 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 577} 578 579Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 580 llvm::SmallVector<llvm::Constant*, 32> indices; 581 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 582 indices.push_back(cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i)))); 583 } 584 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 585 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 586 Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); 587 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 588} 589 590Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 591 TestAndClearIgnoreResultAssign(); 592 593 // Emit subscript expressions in rvalue context's. For most cases, this just 594 // loads the lvalue formed by the subscript expr. However, we have to be 595 // careful, because the base of a vector subscript is occasionally an rvalue, 596 // so we can't get it as an lvalue. 597 if (!E->getBase()->getType()->isVectorType()) 598 return EmitLoadOfLValue(E); 599 600 // Handle the vector case. The base must be a vector, the index must be an 601 // integer value. 602 Value *Base = Visit(E->getBase()); 603 Value *Idx = Visit(E->getIdx()); 604 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerType(); 605 Idx = Builder.CreateIntCast(Idx, 606 llvm::Type::getInt32Ty(CGF.getLLVMContext()), 607 IdxSigned, 608 "vecidxcast"); 609 return Builder.CreateExtractElement(Base, Idx, "vecext"); 610} 611 612/// VisitImplicitCastExpr - Implicit casts are the same as normal casts, but 613/// also handle things like function to pointer-to-function decay, and array to 614/// pointer decay. 615Value *ScalarExprEmitter::VisitImplicitCastExpr(const ImplicitCastExpr *E) { 616 const Expr *Op = E->getSubExpr(); 617 618 // If this is due to array->pointer conversion, emit the array expression as 619 // an l-value. 620 if (Op->getType()->isArrayType()) { 621 assert(E->getCastKind() == CastExpr::CK_ArrayToPointerDecay); 622 Value *V = EmitLValue(Op).getAddress(); // Bitfields can't be arrays. 623 624 // Note that VLA pointers are always decayed, so we don't need to do 625 // anything here. 626 if (!Op->getType()->isVariableArrayType()) { 627 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 628 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 629 ->getElementType()) && 630 "Expected pointer to array"); 631 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 632 } 633 634 // The resultant pointer type can be implicitly casted to other pointer 635 // types as well (e.g. void*) and can be implicitly converted to integer. 636 const llvm::Type *DestTy = ConvertType(E->getType()); 637 if (V->getType() != DestTy) { 638 if (isa<llvm::PointerType>(DestTy)) 639 V = Builder.CreateBitCast(V, DestTy, "ptrconv"); 640 else { 641 assert(isa<llvm::IntegerType>(DestTy) && "Unknown array decay"); 642 V = Builder.CreatePtrToInt(V, DestTy, "ptrconv"); 643 } 644 } 645 return V; 646 } 647 648 return EmitCastExpr(Op, E->getType(), E->getCastKind()); 649} 650 651 652// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 653// have to handle a more broad range of conversions than explicit casts, as they 654// handle things like function to ptr-to-function decay etc. 655Value *ScalarExprEmitter::EmitCastExpr(const Expr *E, QualType DestTy, 656 CastExpr::CastKind Kind) { 657 if (!DestTy->isVoidType()) 658 TestAndClearIgnoreResultAssign(); 659 660 switch (Kind) { 661 default: 662 break; 663 case CastExpr::CK_NullToMemberPointer: 664 return CGF.CGM.EmitNullConstant(DestTy); 665 } 666 667 // Handle cases where the source is an non-complex type. 668 669 if (!CGF.hasAggregateLLVMType(E->getType())) { 670 Value *Src = Visit(const_cast<Expr*>(E)); 671 672 // Use EmitScalarConversion to perform the conversion. 673 return EmitScalarConversion(Src, E->getType(), DestTy); 674 } 675 676 if (E->getType()->isAnyComplexType()) { 677 // Handle cases where the source is a complex type. 678 bool IgnoreImag = true; 679 bool IgnoreImagAssign = true; 680 bool IgnoreReal = IgnoreResultAssign; 681 bool IgnoreRealAssign = IgnoreResultAssign; 682 if (DestTy->isBooleanType()) 683 IgnoreImagAssign = IgnoreImag = false; 684 else if (DestTy->isVoidType()) { 685 IgnoreReal = IgnoreImag = false; 686 IgnoreRealAssign = IgnoreImagAssign = true; 687 } 688 CodeGenFunction::ComplexPairTy V 689 = CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign, 690 IgnoreImagAssign); 691 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 692 } 693 694 // Okay, this is a cast from an aggregate. It must be a cast to void. Just 695 // evaluate the result and return. 696 CGF.EmitAggExpr(E, 0, false, true); 697 return 0; 698} 699 700Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 701 return CGF.EmitCompoundStmt(*E->getSubStmt(), 702 !E->getType()->isVoidType()).getScalarVal(); 703} 704 705Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 706 return Builder.CreateLoad(CGF.GetAddrOfBlockDecl(E), false, "tmp"); 707} 708 709//===----------------------------------------------------------------------===// 710// Unary Operators 711//===----------------------------------------------------------------------===// 712 713Value *ScalarExprEmitter::VisitPrePostIncDec(const UnaryOperator *E, 714 bool isInc, bool isPre) { 715 LValue LV = EmitLValue(E->getSubExpr()); 716 QualType ValTy = E->getSubExpr()->getType(); 717 Value *InVal = CGF.EmitLoadOfLValue(LV, ValTy).getScalarVal(); 718 719 llvm::LLVMContext &VMContext = CGF.getLLVMContext(); 720 721 int AmountVal = isInc ? 1 : -1; 722 723 if (ValTy->isPointerType() && 724 ValTy->getAs<PointerType>()->isVariableArrayType()) { 725 // The amount of the addition/subtraction needs to account for the VLA size 726 CGF.ErrorUnsupported(E, "VLA pointer inc/dec"); 727 } 728 729 Value *NextVal; 730 if (const llvm::PointerType *PT = 731 dyn_cast<llvm::PointerType>(InVal->getType())) { 732 llvm::Constant *Inc = 733 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), AmountVal); 734 if (!isa<llvm::FunctionType>(PT->getElementType())) { 735 QualType PTEE = ValTy->getPointeeType(); 736 if (const ObjCInterfaceType *OIT = 737 dyn_cast<ObjCInterfaceType>(PTEE)) { 738 // Handle interface types, which are not represented with a concrete type. 739 int size = CGF.getContext().getTypeSize(OIT) / 8; 740 if (!isInc) 741 size = -size; 742 Inc = llvm::ConstantInt::get(Inc->getType(), size); 743 const llvm::Type *i8Ty = 744 llvm::PointerType::getUnqual(llvm::Type::getInt8Ty(VMContext)); 745 InVal = Builder.CreateBitCast(InVal, i8Ty); 746 NextVal = Builder.CreateGEP(InVal, Inc, "add.ptr"); 747 llvm::Value *lhs = LV.getAddress(); 748 lhs = Builder.CreateBitCast(lhs, llvm::PointerType::getUnqual(i8Ty)); 749 LV = LValue::MakeAddr(lhs, ValTy.getCVRQualifiers(), 750 CGF.getContext().getObjCGCAttrKind(ValTy)); 751 } else 752 NextVal = Builder.CreateInBoundsGEP(InVal, Inc, "ptrincdec"); 753 } else { 754 const llvm::Type *i8Ty = 755 llvm::PointerType::getUnqual(llvm::Type::getInt8Ty(VMContext)); 756 NextVal = Builder.CreateBitCast(InVal, i8Ty, "tmp"); 757 NextVal = Builder.CreateGEP(NextVal, Inc, "ptrincdec"); 758 NextVal = Builder.CreateBitCast(NextVal, InVal->getType()); 759 } 760 } else if (InVal->getType() == llvm::Type::getInt1Ty(VMContext) && isInc) { 761 // Bool++ is an interesting case, due to promotion rules, we get: 762 // Bool++ -> Bool = Bool+1 -> Bool = (int)Bool+1 -> 763 // Bool = ((int)Bool+1) != 0 764 // An interesting aspect of this is that increment is always true. 765 // Decrement does not have this property. 766 NextVal = llvm::ConstantInt::getTrue(VMContext); 767 } else if (isa<llvm::IntegerType>(InVal->getType())) { 768 NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); 769 770 // Signed integer overflow is undefined behavior. 771 if (ValTy->isSignedIntegerType()) 772 NextVal = Builder.CreateNSWAdd(InVal, NextVal, isInc ? "inc" : "dec"); 773 else 774 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 775 } else { 776 // Add the inc/dec to the real part. 777 if (InVal->getType() == llvm::Type::getFloatTy(VMContext)) 778 NextVal = 779 llvm::ConstantFP::get(VMContext, 780 llvm::APFloat(static_cast<float>(AmountVal))); 781 else if (InVal->getType() == llvm::Type::getDoubleTy(VMContext)) 782 NextVal = 783 llvm::ConstantFP::get(VMContext, 784 llvm::APFloat(static_cast<double>(AmountVal))); 785 else { 786 llvm::APFloat F(static_cast<float>(AmountVal)); 787 bool ignored; 788 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, 789 &ignored); 790 NextVal = llvm::ConstantFP::get(VMContext, F); 791 } 792 NextVal = Builder.CreateFAdd(InVal, NextVal, isInc ? "inc" : "dec"); 793 } 794 795 // Store the updated result through the lvalue. 796 if (LV.isBitfield()) 797 CGF.EmitStoreThroughBitfieldLValue(RValue::get(NextVal), LV, ValTy, 798 &NextVal); 799 else 800 CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV, ValTy); 801 802 // If this is a postinc, return the value read from memory, otherwise use the 803 // updated value. 804 return isPre ? NextVal : InVal; 805} 806 807 808Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 809 TestAndClearIgnoreResultAssign(); 810 Value *Op = Visit(E->getSubExpr()); 811 if (Op->getType()->isFPOrFPVector()) 812 return Builder.CreateFNeg(Op, "neg"); 813 return Builder.CreateNeg(Op, "neg"); 814} 815 816Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 817 TestAndClearIgnoreResultAssign(); 818 Value *Op = Visit(E->getSubExpr()); 819 return Builder.CreateNot(Op, "neg"); 820} 821 822Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 823 // Compare operand to zero. 824 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 825 826 // Invert value. 827 // TODO: Could dynamically modify easy computations here. For example, if 828 // the operand is an icmp ne, turn into icmp eq. 829 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 830 831 // ZExt result to the expr type. 832 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 833} 834 835/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of 836/// argument of the sizeof expression as an integer. 837Value * 838ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { 839 QualType TypeToSize = E->getTypeOfArgument(); 840 if (E->isSizeOf()) { 841 if (const VariableArrayType *VAT = 842 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 843 if (E->isArgumentType()) { 844 // sizeof(type) - make sure to emit the VLA size. 845 CGF.EmitVLASize(TypeToSize); 846 } else { 847 // C99 6.5.3.4p2: If the argument is an expression of type 848 // VLA, it is evaluated. 849 CGF.EmitAnyExpr(E->getArgumentExpr()); 850 } 851 852 return CGF.GetVLASize(VAT); 853 } 854 } 855 856 // If this isn't sizeof(vla), the result must be constant; use the 857 // constant folding logic so we don't have to duplicate it here. 858 Expr::EvalResult Result; 859 E->Evaluate(Result, CGF.getContext()); 860 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 861} 862 863Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 864 Expr *Op = E->getSubExpr(); 865 if (Op->getType()->isAnyComplexType()) 866 return CGF.EmitComplexExpr(Op, false, true, false, true).first; 867 return Visit(Op); 868} 869Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 870 Expr *Op = E->getSubExpr(); 871 if (Op->getType()->isAnyComplexType()) 872 return CGF.EmitComplexExpr(Op, true, false, true, false).second; 873 874 // __imag on a scalar returns zero. Emit the subexpr to ensure side 875 // effects are evaluated, but not the actual value. 876 if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) 877 CGF.EmitLValue(Op); 878 else 879 CGF.EmitScalarExpr(Op, true); 880 return llvm::Constant::getNullValue(ConvertType(E->getType())); 881} 882 883Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) 884{ 885 Value* ResultAsPtr = EmitLValue(E->getSubExpr()).getAddress(); 886 const llvm::Type* ResultType = ConvertType(E->getType()); 887 return Builder.CreatePtrToInt(ResultAsPtr, ResultType, "offsetof"); 888} 889 890//===----------------------------------------------------------------------===// 891// Binary Operators 892//===----------------------------------------------------------------------===// 893 894BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 895 TestAndClearIgnoreResultAssign(); 896 BinOpInfo Result; 897 Result.LHS = Visit(E->getLHS()); 898 Result.RHS = Visit(E->getRHS()); 899 Result.Ty = E->getType(); 900 Result.E = E; 901 return Result; 902} 903 904Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 905 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 906 bool Ignore = TestAndClearIgnoreResultAssign(); 907 QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType(); 908 909 BinOpInfo OpInfo; 910 911 if (E->getComputationResultType()->isAnyComplexType()) { 912 // This needs to go through the complex expression emitter, but 913 // it's a tad complicated to do that... I'm leaving it out for now. 914 // (Note that we do actually need the imaginary part of the RHS for 915 // multiplication and division.) 916 CGF.ErrorUnsupported(E, "complex compound assignment"); 917 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 918 } 919 920 // Emit the RHS first. __block variables need to have the rhs evaluated 921 // first, plus this should improve codegen a little. 922 OpInfo.RHS = Visit(E->getRHS()); 923 OpInfo.Ty = E->getComputationResultType(); 924 OpInfo.E = E; 925 // Load/convert the LHS. 926 LValue LHSLV = EmitLValue(E->getLHS()); 927 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 928 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 929 E->getComputationLHSType()); 930 931 // Expand the binary operator. 932 Value *Result = (this->*Func)(OpInfo); 933 934 // Convert the result back to the LHS type. 935 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 936 937 // Store the result value into the LHS lvalue. Bit-fields are 938 // handled specially because the result is altered by the store, 939 // i.e., [C99 6.5.16p1] 'An assignment expression has the value of 940 // the left operand after the assignment...'. 941 if (LHSLV.isBitfield()) { 942 if (!LHSLV.isVolatileQualified()) { 943 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, 944 &Result); 945 return Result; 946 } else 947 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy); 948 } else 949 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); 950 if (Ignore) 951 return 0; 952 return EmitLoadOfLValue(LHSLV, E->getType()); 953} 954 955 956Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 957 if (Ops.LHS->getType()->isFPOrFPVector()) 958 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 959 else if (Ops.Ty->isUnsignedIntegerType()) 960 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 961 else 962 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 963} 964 965Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 966 // Rem in C can't be a floating point type: C99 6.5.5p2. 967 if (Ops.Ty->isUnsignedIntegerType()) 968 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 969 else 970 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 971} 972 973Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 974 unsigned IID; 975 unsigned OpID = 0; 976 977 switch (Ops.E->getOpcode()) { 978 case BinaryOperator::Add: 979 case BinaryOperator::AddAssign: 980 OpID = 1; 981 IID = llvm::Intrinsic::sadd_with_overflow; 982 break; 983 case BinaryOperator::Sub: 984 case BinaryOperator::SubAssign: 985 OpID = 2; 986 IID = llvm::Intrinsic::ssub_with_overflow; 987 break; 988 case BinaryOperator::Mul: 989 case BinaryOperator::MulAssign: 990 OpID = 3; 991 IID = llvm::Intrinsic::smul_with_overflow; 992 break; 993 default: 994 assert(false && "Unsupported operation for overflow detection"); 995 IID = 0; 996 } 997 OpID <<= 1; 998 OpID |= 1; 999 1000 const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1001 1002 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1); 1003 1004 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1005 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1006 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1007 1008 // Branch in case of overflow. 1009 llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); 1010 llvm::BasicBlock *overflowBB = 1011 CGF.createBasicBlock("overflow", CGF.CurFn); 1012 llvm::BasicBlock *continueBB = 1013 CGF.createBasicBlock("overflow.continue", CGF.CurFn); 1014 1015 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1016 1017 // Handle overflow 1018 1019 Builder.SetInsertPoint(overflowBB); 1020 1021 // Handler is: 1022 // long long *__overflow_handler)(long long a, long long b, char op, 1023 // char width) 1024 std::vector<const llvm::Type*> handerArgTypes; 1025 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1026 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1027 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1028 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1029 llvm::FunctionType *handlerTy = llvm::FunctionType::get( 1030 llvm::Type::getInt64Ty(VMContext), handerArgTypes, false); 1031 llvm::Value *handlerFunction = 1032 CGF.CGM.getModule().getOrInsertGlobal("__overflow_handler", 1033 llvm::PointerType::getUnqual(handlerTy)); 1034 handlerFunction = Builder.CreateLoad(handlerFunction); 1035 1036 llvm::Value *handlerResult = Builder.CreateCall4(handlerFunction, 1037 Builder.CreateSExt(Ops.LHS, llvm::Type::getInt64Ty(VMContext)), 1038 Builder.CreateSExt(Ops.RHS, llvm::Type::getInt64Ty(VMContext)), 1039 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), OpID), 1040 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), 1041 cast<llvm::IntegerType>(opTy)->getBitWidth())); 1042 1043 handlerResult = Builder.CreateTrunc(handlerResult, opTy); 1044 1045 Builder.CreateBr(continueBB); 1046 1047 // Set up the continuation 1048 Builder.SetInsertPoint(continueBB); 1049 // Get the correct result 1050 llvm::PHINode *phi = Builder.CreatePHI(opTy); 1051 phi->reserveOperandSpace(2); 1052 phi->addIncoming(result, initialBB); 1053 phi->addIncoming(handlerResult, overflowBB); 1054 1055 return phi; 1056} 1057 1058Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 1059 if (!Ops.Ty->isAnyPointerType()) { 1060 if (CGF.getContext().getLangOptions().OverflowChecking && 1061 Ops.Ty->isSignedIntegerType()) 1062 return EmitOverflowCheckedBinOp(Ops); 1063 1064 if (Ops.LHS->getType()->isFPOrFPVector()) 1065 return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add"); 1066 1067 // Signed integer overflow is undefined behavior. 1068 if (Ops.Ty->isSignedIntegerType()) 1069 return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add"); 1070 1071 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1072 } 1073 1074 if (Ops.Ty->isPointerType() && 1075 Ops.Ty->getAs<PointerType>()->isVariableArrayType()) { 1076 // The amount of the addition needs to account for the VLA size 1077 CGF.ErrorUnsupported(Ops.E, "VLA pointer addition"); 1078 } 1079 Value *Ptr, *Idx; 1080 Expr *IdxExp; 1081 const PointerType *PT = Ops.E->getLHS()->getType()->getAs<PointerType>(); 1082 const ObjCObjectPointerType *OPT = 1083 Ops.E->getLHS()->getType()->getAsObjCObjectPointerType(); 1084 if (PT || OPT) { 1085 Ptr = Ops.LHS; 1086 Idx = Ops.RHS; 1087 IdxExp = Ops.E->getRHS(); 1088 } else { // int + pointer 1089 PT = Ops.E->getRHS()->getType()->getAs<PointerType>(); 1090 OPT = Ops.E->getRHS()->getType()->getAsObjCObjectPointerType(); 1091 assert((PT || OPT) && "Invalid add expr"); 1092 Ptr = Ops.RHS; 1093 Idx = Ops.LHS; 1094 IdxExp = Ops.E->getLHS(); 1095 } 1096 1097 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1098 if (Width < CGF.LLVMPointerWidth) { 1099 // Zero or sign extend the pointer value based on whether the index is 1100 // signed or not. 1101 const llvm::Type *IdxType = 1102 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1103 if (IdxExp->getType()->isSignedIntegerType()) 1104 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1105 else 1106 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1107 } 1108 const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType(); 1109 // Handle interface types, which are not represented with a concrete 1110 // type. 1111 if (const ObjCInterfaceType *OIT = dyn_cast<ObjCInterfaceType>(ElementType)) { 1112 llvm::Value *InterfaceSize = 1113 llvm::ConstantInt::get(Idx->getType(), 1114 CGF.getContext().getTypeSize(OIT) / 8); 1115 Idx = Builder.CreateMul(Idx, InterfaceSize); 1116 const llvm::Type *i8Ty = 1117 llvm::PointerType::getUnqual(llvm::Type::getInt8Ty(VMContext)); 1118 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1119 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1120 return Builder.CreateBitCast(Res, Ptr->getType()); 1121 } 1122 1123 // Explicitly handle GNU void* and function pointer arithmetic 1124 // extensions. The GNU void* casts amount to no-ops since our void* 1125 // type is i8*, but this is future proof. 1126 if (ElementType->isVoidType() || ElementType->isFunctionType()) { 1127 const llvm::Type *i8Ty = 1128 llvm::PointerType::getUnqual(llvm::Type::getInt8Ty(VMContext)); 1129 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1130 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1131 return Builder.CreateBitCast(Res, Ptr->getType()); 1132 } 1133 1134 return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr"); 1135} 1136 1137Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 1138 if (!isa<llvm::PointerType>(Ops.LHS->getType())) { 1139 if (CGF.getContext().getLangOptions().OverflowChecking 1140 && Ops.Ty->isSignedIntegerType()) 1141 return EmitOverflowCheckedBinOp(Ops); 1142 1143 if (Ops.LHS->getType()->isFPOrFPVector()) 1144 return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub"); 1145 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1146 } 1147 1148 if (Ops.E->getLHS()->getType()->isPointerType() && 1149 Ops.E->getLHS()->getType()->getAs<PointerType>()->isVariableArrayType()) { 1150 // The amount of the addition needs to account for the VLA size for 1151 // ptr-int 1152 // The amount of the division needs to account for the VLA size for 1153 // ptr-ptr. 1154 CGF.ErrorUnsupported(Ops.E, "VLA pointer subtraction"); 1155 } 1156 1157 const QualType LHSType = Ops.E->getLHS()->getType(); 1158 const QualType LHSElementType = LHSType->getPointeeType(); 1159 if (!isa<llvm::PointerType>(Ops.RHS->getType())) { 1160 // pointer - int 1161 Value *Idx = Ops.RHS; 1162 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1163 if (Width < CGF.LLVMPointerWidth) { 1164 // Zero or sign extend the pointer value based on whether the index is 1165 // signed or not. 1166 const llvm::Type *IdxType = 1167 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1168 if (Ops.E->getRHS()->getType()->isSignedIntegerType()) 1169 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1170 else 1171 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1172 } 1173 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); 1174 1175 // Handle interface types, which are not represented with a concrete 1176 // type. 1177 if (const ObjCInterfaceType *OIT = 1178 dyn_cast<ObjCInterfaceType>(LHSElementType)) { 1179 llvm::Value *InterfaceSize = 1180 llvm::ConstantInt::get(Idx->getType(), 1181 CGF.getContext().getTypeSize(OIT) / 8); 1182 Idx = Builder.CreateMul(Idx, InterfaceSize); 1183 const llvm::Type *i8Ty = 1184 llvm::PointerType::getUnqual(llvm::Type::getInt8Ty(VMContext)); 1185 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1186 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr"); 1187 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1188 } 1189 1190 // Explicitly handle GNU void* and function pointer arithmetic 1191 // extensions. The GNU void* casts amount to no-ops since our 1192 // void* type is i8*, but this is future proof. 1193 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1194 const llvm::Type *i8Ty = 1195 llvm::PointerType::getUnqual(llvm::Type::getInt8Ty(VMContext)); 1196 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1197 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); 1198 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1199 } 1200 1201 return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr"); 1202 } else { 1203 // pointer - pointer 1204 Value *LHS = Ops.LHS; 1205 Value *RHS = Ops.RHS; 1206 1207 uint64_t ElementSize; 1208 1209 // Handle GCC extension for pointer arithmetic on void* and function pointer 1210 // types. 1211 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1212 ElementSize = 1; 1213 } else { 1214 ElementSize = CGF.getContext().getTypeSize(LHSElementType) / 8; 1215 } 1216 1217 const llvm::Type *ResultType = ConvertType(Ops.Ty); 1218 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 1219 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 1220 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 1221 1222 // Optimize out the shift for element size of 1. 1223 if (ElementSize == 1) 1224 return BytesBetween; 1225 1226 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 1227 // pointer difference in C is only defined in the case where both 1228 // operands are pointing to elements of an array. 1229 Value *BytesPerElt = llvm::ConstantInt::get(ResultType, ElementSize); 1230 return Builder.CreateExactSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 1231 } 1232} 1233 1234Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 1235 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1236 // RHS to the same size as the LHS. 1237 Value *RHS = Ops.RHS; 1238 if (Ops.LHS->getType() != RHS->getType()) 1239 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1240 1241 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 1242} 1243 1244Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 1245 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1246 // RHS to the same size as the LHS. 1247 Value *RHS = Ops.RHS; 1248 if (Ops.LHS->getType() != RHS->getType()) 1249 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1250 1251 if (Ops.Ty->isUnsignedIntegerType()) 1252 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 1253 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 1254} 1255 1256Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 1257 unsigned SICmpOpc, unsigned FCmpOpc) { 1258 TestAndClearIgnoreResultAssign(); 1259 Value *Result; 1260 QualType LHSTy = E->getLHS()->getType(); 1261 if (!LHSTy->isAnyComplexType()) { 1262 Value *LHS = Visit(E->getLHS()); 1263 Value *RHS = Visit(E->getRHS()); 1264 1265 if (LHS->getType()->isFPOrFPVector()) { 1266 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 1267 LHS, RHS, "cmp"); 1268 } else if (LHSTy->isSignedIntegerType()) { 1269 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 1270 LHS, RHS, "cmp"); 1271 } else { 1272 // Unsigned integers and pointers. 1273 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1274 LHS, RHS, "cmp"); 1275 } 1276 1277 // If this is a vector comparison, sign extend the result to the appropriate 1278 // vector integer type and return it (don't convert to bool). 1279 if (LHSTy->isVectorType()) 1280 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 1281 1282 } else { 1283 // Complex Comparison: can only be an equality comparison. 1284 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 1285 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 1286 1287 QualType CETy = LHSTy->getAsComplexType()->getElementType(); 1288 1289 Value *ResultR, *ResultI; 1290 if (CETy->isRealFloatingType()) { 1291 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1292 LHS.first, RHS.first, "cmp.r"); 1293 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1294 LHS.second, RHS.second, "cmp.i"); 1295 } else { 1296 // Complex comparisons can only be equality comparisons. As such, signed 1297 // and unsigned opcodes are the same. 1298 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1299 LHS.first, RHS.first, "cmp.r"); 1300 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1301 LHS.second, RHS.second, "cmp.i"); 1302 } 1303 1304 if (E->getOpcode() == BinaryOperator::EQ) { 1305 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 1306 } else { 1307 assert(E->getOpcode() == BinaryOperator::NE && 1308 "Complex comparison other than == or != ?"); 1309 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 1310 } 1311 } 1312 1313 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 1314} 1315 1316Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 1317 bool Ignore = TestAndClearIgnoreResultAssign(); 1318 1319 // __block variables need to have the rhs evaluated first, plus this should 1320 // improve codegen just a little. 1321 Value *RHS = Visit(E->getRHS()); 1322 LValue LHS = EmitLValue(E->getLHS()); 1323 1324 // Store the value into the LHS. Bit-fields are handled specially 1325 // because the result is altered by the store, i.e., [C99 6.5.16p1] 1326 // 'An assignment expression has the value of the left operand after 1327 // the assignment...'. 1328 if (LHS.isBitfield()) { 1329 if (!LHS.isVolatileQualified()) { 1330 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), 1331 &RHS); 1332 return RHS; 1333 } else 1334 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType()); 1335 } else 1336 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 1337 if (Ignore) 1338 return 0; 1339 return EmitLoadOfLValue(LHS, E->getType()); 1340} 1341 1342Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 1343 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 1344 // If we have 1 && X, just emit X without inserting the control flow. 1345 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1346 if (Cond == 1) { // If we have 1 && X, just emit X. 1347 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1348 // ZExt result to int. 1349 return Builder.CreateZExt(RHSCond, CGF.LLVMIntTy, "land.ext"); 1350 } 1351 1352 // 0 && RHS: If it is safe, just elide the RHS, and return 0. 1353 if (!CGF.ContainsLabel(E->getRHS())) 1354 return llvm::Constant::getNullValue(CGF.LLVMIntTy); 1355 } 1356 1357 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 1358 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 1359 1360 // Branch on the LHS first. If it is false, go to the failure (cont) block. 1361 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 1362 1363 // Any edges into the ContBlock are now from an (indeterminate number of) 1364 // edges from this first condition. All of these values will be false. Start 1365 // setting up the PHI node in the Cont Block for this. 1366 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1367 "", ContBlock); 1368 PN->reserveOperandSpace(2); // Normal case, two inputs. 1369 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1370 PI != PE; ++PI) 1371 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 1372 1373 CGF.PushConditionalTempDestruction(); 1374 CGF.EmitBlock(RHSBlock); 1375 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1376 CGF.PopConditionalTempDestruction(); 1377 1378 // Reaquire the RHS block, as there may be subblocks inserted. 1379 RHSBlock = Builder.GetInsertBlock(); 1380 1381 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1382 // into the phi node for the edge with the value of RHSCond. 1383 CGF.EmitBlock(ContBlock); 1384 PN->addIncoming(RHSCond, RHSBlock); 1385 1386 // ZExt result to int. 1387 return Builder.CreateZExt(PN, CGF.LLVMIntTy, "land.ext"); 1388} 1389 1390Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 1391 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 1392 // If we have 0 || X, just emit X without inserting the control flow. 1393 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1394 if (Cond == -1) { // If we have 0 || X, just emit X. 1395 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1396 // ZExt result to int. 1397 return Builder.CreateZExt(RHSCond, CGF.LLVMIntTy, "lor.ext"); 1398 } 1399 1400 // 1 || RHS: If it is safe, just elide the RHS, and return 1. 1401 if (!CGF.ContainsLabel(E->getRHS())) 1402 return llvm::ConstantInt::get(CGF.LLVMIntTy, 1); 1403 } 1404 1405 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 1406 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 1407 1408 // Branch on the LHS first. If it is true, go to the success (cont) block. 1409 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 1410 1411 // Any edges into the ContBlock are now from an (indeterminate number of) 1412 // edges from this first condition. All of these values will be true. Start 1413 // setting up the PHI node in the Cont Block for this. 1414 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1415 "", ContBlock); 1416 PN->reserveOperandSpace(2); // Normal case, two inputs. 1417 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1418 PI != PE; ++PI) 1419 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 1420 1421 CGF.PushConditionalTempDestruction(); 1422 1423 // Emit the RHS condition as a bool value. 1424 CGF.EmitBlock(RHSBlock); 1425 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1426 1427 CGF.PopConditionalTempDestruction(); 1428 1429 // Reaquire the RHS block, as there may be subblocks inserted. 1430 RHSBlock = Builder.GetInsertBlock(); 1431 1432 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1433 // into the phi node for the edge with the value of RHSCond. 1434 CGF.EmitBlock(ContBlock); 1435 PN->addIncoming(RHSCond, RHSBlock); 1436 1437 // ZExt result to int. 1438 return Builder.CreateZExt(PN, CGF.LLVMIntTy, "lor.ext"); 1439} 1440 1441Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 1442 CGF.EmitStmt(E->getLHS()); 1443 CGF.EnsureInsertPoint(); 1444 return Visit(E->getRHS()); 1445} 1446 1447//===----------------------------------------------------------------------===// 1448// Other Operators 1449//===----------------------------------------------------------------------===// 1450 1451/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 1452/// expression is cheap enough and side-effect-free enough to evaluate 1453/// unconditionally instead of conditionally. This is used to convert control 1454/// flow into selects in some cases. 1455static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E) { 1456 if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) 1457 return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr()); 1458 1459 // TODO: Allow anything we can constant fold to an integer or fp constant. 1460 if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || 1461 isa<FloatingLiteral>(E)) 1462 return true; 1463 1464 // Non-volatile automatic variables too, to get "cond ? X : Y" where 1465 // X and Y are local variables. 1466 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 1467 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 1468 if (VD->hasLocalStorage() && !VD->getType().isVolatileQualified()) 1469 return true; 1470 1471 return false; 1472} 1473 1474 1475Value *ScalarExprEmitter:: 1476VisitConditionalOperator(const ConditionalOperator *E) { 1477 TestAndClearIgnoreResultAssign(); 1478 // If the condition constant folds and can be elided, try to avoid emitting 1479 // the condition and the dead arm. 1480 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ 1481 Expr *Live = E->getLHS(), *Dead = E->getRHS(); 1482 if (Cond == -1) 1483 std::swap(Live, Dead); 1484 1485 // If the dead side doesn't have labels we need, and if the Live side isn't 1486 // the gnu missing ?: extension (which we could handle, but don't bother 1487 // to), just emit the Live part. 1488 if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part 1489 Live) // Live part isn't missing. 1490 return Visit(Live); 1491 } 1492 1493 1494 // If this is a really simple expression (like x ? 4 : 5), emit this as a 1495 // select instead of as control flow. We can only do this if it is cheap and 1496 // safe to evaluate the LHS and RHS unconditionally. 1497 if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS()) && 1498 isCheapEnoughToEvaluateUnconditionally(E->getRHS())) { 1499 llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); 1500 llvm::Value *LHS = Visit(E->getLHS()); 1501 llvm::Value *RHS = Visit(E->getRHS()); 1502 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 1503 } 1504 1505 1506 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 1507 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 1508 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 1509 Value *CondVal = 0; 1510 1511 // If we don't have the GNU missing condition extension, emit a branch on 1512 // bool the normal way. 1513 if (E->getLHS()) { 1514 // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for 1515 // the branch on bool. 1516 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); 1517 } else { 1518 // Otherwise, for the ?: extension, evaluate the conditional and then 1519 // convert it to bool the hard way. We do this explicitly because we need 1520 // the unconverted value for the missing middle value of the ?:. 1521 CondVal = CGF.EmitScalarExpr(E->getCond()); 1522 1523 // In some cases, EmitScalarConversion will delete the "CondVal" expression 1524 // if there are no extra uses (an optimization). Inhibit this by making an 1525 // extra dead use, because we're going to add a use of CondVal later. We 1526 // don't use the builder for this, because we don't want it to get optimized 1527 // away. This leaves dead code, but the ?: extension isn't common. 1528 new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", 1529 Builder.GetInsertBlock()); 1530 1531 Value *CondBoolVal = 1532 CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 1533 CGF.getContext().BoolTy); 1534 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 1535 } 1536 1537 CGF.PushConditionalTempDestruction(); 1538 CGF.EmitBlock(LHSBlock); 1539 1540 // Handle the GNU extension for missing LHS. 1541 Value *LHS; 1542 if (E->getLHS()) 1543 LHS = Visit(E->getLHS()); 1544 else // Perform promotions, to handle cases like "short ?: int" 1545 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); 1546 1547 CGF.PopConditionalTempDestruction(); 1548 LHSBlock = Builder.GetInsertBlock(); 1549 CGF.EmitBranch(ContBlock); 1550 1551 CGF.PushConditionalTempDestruction(); 1552 CGF.EmitBlock(RHSBlock); 1553 1554 Value *RHS = Visit(E->getRHS()); 1555 CGF.PopConditionalTempDestruction(); 1556 RHSBlock = Builder.GetInsertBlock(); 1557 CGF.EmitBranch(ContBlock); 1558 1559 CGF.EmitBlock(ContBlock); 1560 1561 if (!LHS || !RHS) { 1562 assert(E->getType()->isVoidType() && "Non-void value should have a value"); 1563 return 0; 1564 } 1565 1566 // Create a PHI node for the real part. 1567 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 1568 PN->reserveOperandSpace(2); 1569 PN->addIncoming(LHS, LHSBlock); 1570 PN->addIncoming(RHS, RHSBlock); 1571 return PN; 1572} 1573 1574Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 1575 return Visit(E->getChosenSubExpr(CGF.getContext())); 1576} 1577 1578Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 1579 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 1580 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 1581 1582 // If EmitVAArg fails, we fall back to the LLVM instruction. 1583 if (!ArgPtr) 1584 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 1585 1586 // FIXME Volatility. 1587 return Builder.CreateLoad(ArgPtr); 1588} 1589 1590Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { 1591 return CGF.BuildBlockLiteralTmp(BE); 1592} 1593 1594//===----------------------------------------------------------------------===// 1595// Entry Point into this File 1596//===----------------------------------------------------------------------===// 1597 1598/// EmitScalarExpr - Emit the computation of the specified expression of 1599/// scalar type, ignoring the result. 1600Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 1601 assert(E && !hasAggregateLLVMType(E->getType()) && 1602 "Invalid scalar expression to emit"); 1603 1604 return ScalarExprEmitter(*this, IgnoreResultAssign) 1605 .Visit(const_cast<Expr*>(E)); 1606} 1607 1608/// EmitScalarConversion - Emit a conversion from the specified type to the 1609/// specified destination type, both of which are LLVM scalar types. 1610Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 1611 QualType DstTy) { 1612 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 1613 "Invalid scalar expression to emit"); 1614 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 1615} 1616 1617/// EmitComplexToScalarConversion - Emit a conversion from the specified 1618/// complex type to the specified destination type, where the destination 1619/// type is an LLVM scalar type. 1620Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 1621 QualType SrcTy, 1622 QualType DstTy) { 1623 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 1624 "Invalid complex -> scalar conversion"); 1625 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 1626 DstTy); 1627} 1628 1629Value *CodeGenFunction::EmitShuffleVector(Value* V1, Value *V2, ...) { 1630 assert(V1->getType() == V2->getType() && 1631 "Vector operands must be of the same type"); 1632 unsigned NumElements = 1633 cast<llvm::VectorType>(V1->getType())->getNumElements(); 1634 1635 va_list va; 1636 va_start(va, V2); 1637 1638 llvm::SmallVector<llvm::Constant*, 16> Args; 1639 for (unsigned i = 0; i < NumElements; i++) { 1640 int n = va_arg(va, int); 1641 assert(n >= 0 && n < (int)NumElements * 2 && 1642 "Vector shuffle index out of bounds!"); 1643 Args.push_back(llvm::ConstantInt::get( 1644 llvm::Type::getInt32Ty(VMContext), n)); 1645 } 1646 1647 const char *Name = va_arg(va, const char *); 1648 va_end(va); 1649 1650 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 1651 1652 return Builder.CreateShuffleVector(V1, V2, Mask, Name); 1653} 1654 1655llvm::Value *CodeGenFunction::EmitVector(llvm::Value * const *Vals, 1656 unsigned NumVals, bool isSplat) { 1657 llvm::Value *Vec 1658 = llvm::UndefValue::get(llvm::VectorType::get(Vals[0]->getType(), NumVals)); 1659 1660 for (unsigned i = 0, e = NumVals; i != e; ++i) { 1661 llvm::Value *Val = isSplat ? Vals[0] : Vals[i]; 1662 llvm::Value *Idx = llvm::ConstantInt::get( 1663 llvm::Type::getInt32Ty(VMContext), i); 1664 Vec = Builder.CreateInsertElement(Vec, Val, Idx, "tmp"); 1665 } 1666 1667 return Vec; 1668} 1669