CGExprScalar.cpp revision c1eb14a66fdd955aff3f957a5843295f27952bdd
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 type 94 /// 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 *VisitCastExpr(const CastExpr *E) { 230 // Make sure to evaluate VLA bounds now so that we have them for later. 231 if (E->getType()->isVariablyModifiedType()) 232 CGF.EmitVLASize(E->getType()); 233 234 return EmitCastExpr(E->getSubExpr(), E->getType(), E->getCastKind()); 235 } 236 Value *EmitCastExpr(const Expr *E, QualType T, CastExpr::CastKind Kind); 237 238 Value *VisitCallExpr(const CallExpr *E) { 239 if (E->getCallReturnType()->isReferenceType()) 240 return EmitLoadOfLValue(E); 241 242 return CGF.EmitCallExpr(E).getScalarVal(); 243 } 244 245 Value *VisitStmtExpr(const StmtExpr *E); 246 247 Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E); 248 249 // Unary Operators. 250 Value *VisitPrePostIncDec(const UnaryOperator *E, bool isInc, bool isPre); 251 Value *VisitUnaryPostDec(const UnaryOperator *E) { 252 return VisitPrePostIncDec(E, false, false); 253 } 254 Value *VisitUnaryPostInc(const UnaryOperator *E) { 255 return VisitPrePostIncDec(E, true, false); 256 } 257 Value *VisitUnaryPreDec(const UnaryOperator *E) { 258 return VisitPrePostIncDec(E, false, true); 259 } 260 Value *VisitUnaryPreInc(const UnaryOperator *E) { 261 return VisitPrePostIncDec(E, true, true); 262 } 263 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 264 return EmitLValue(E->getSubExpr()).getAddress(); 265 } 266 Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } 267 Value *VisitUnaryPlus(const UnaryOperator *E) { 268 // This differs from gcc, though, most likely due to a bug in gcc. 269 TestAndClearIgnoreResultAssign(); 270 return Visit(E->getSubExpr()); 271 } 272 Value *VisitUnaryMinus (const UnaryOperator *E); 273 Value *VisitUnaryNot (const UnaryOperator *E); 274 Value *VisitUnaryLNot (const UnaryOperator *E); 275 Value *VisitUnaryReal (const UnaryOperator *E); 276 Value *VisitUnaryImag (const UnaryOperator *E); 277 Value *VisitUnaryExtension(const UnaryOperator *E) { 278 return Visit(E->getSubExpr()); 279 } 280 Value *VisitUnaryOffsetOf(const UnaryOperator *E); 281 282 // C++ 283 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 284 return Visit(DAE->getExpr()); 285 } 286 Value *VisitCXXThisExpr(CXXThisExpr *TE) { 287 return CGF.LoadCXXThis(); 288 } 289 290 Value *VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) { 291 return CGF.EmitCXXExprWithTemporaries(E).getScalarVal(); 292 } 293 Value *VisitCXXNewExpr(const CXXNewExpr *E) { 294 return CGF.EmitCXXNewExpr(E); 295 } 296 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { 297 CGF.EmitCXXDeleteExpr(E); 298 return 0; 299 } 300 301 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { 302 // C++ [expr.pseudo]p1: 303 // The result shall only be used as the operand for the function call 304 // operator (), and the result of such a call has type void. The only 305 // effect is the evaluation of the postfix-expression before the dot or 306 // arrow. 307 CGF.EmitScalarExpr(E->getBase()); 308 return 0; 309 } 310 311 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { 312 return llvm::Constant::getNullValue(ConvertType(E->getType())); 313 } 314 315 // Binary Operators. 316 Value *EmitMul(const BinOpInfo &Ops) { 317 if (CGF.getContext().getLangOptions().OverflowChecking 318 && Ops.Ty->isSignedIntegerType()) 319 return EmitOverflowCheckedBinOp(Ops); 320 if (Ops.LHS->getType()->isFPOrFPVector()) 321 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 322 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 323 } 324 /// Create a binary op that checks for overflow. 325 /// Currently only supports +, - and *. 326 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 327 Value *EmitDiv(const BinOpInfo &Ops); 328 Value *EmitRem(const BinOpInfo &Ops); 329 Value *EmitAdd(const BinOpInfo &Ops); 330 Value *EmitSub(const BinOpInfo &Ops); 331 Value *EmitShl(const BinOpInfo &Ops); 332 Value *EmitShr(const BinOpInfo &Ops); 333 Value *EmitAnd(const BinOpInfo &Ops) { 334 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 335 } 336 Value *EmitXor(const BinOpInfo &Ops) { 337 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 338 } 339 Value *EmitOr (const BinOpInfo &Ops) { 340 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 341 } 342 343 BinOpInfo EmitBinOps(const BinaryOperator *E); 344 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 345 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 346 347 // Binary operators and binary compound assignment operators. 348#define HANDLEBINOP(OP) \ 349 Value *VisitBin ## OP(const BinaryOperator *E) { \ 350 return Emit ## OP(EmitBinOps(E)); \ 351 } \ 352 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 353 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 354 } 355 HANDLEBINOP(Mul); 356 HANDLEBINOP(Div); 357 HANDLEBINOP(Rem); 358 HANDLEBINOP(Add); 359 HANDLEBINOP(Sub); 360 HANDLEBINOP(Shl); 361 HANDLEBINOP(Shr); 362 HANDLEBINOP(And); 363 HANDLEBINOP(Xor); 364 HANDLEBINOP(Or); 365#undef HANDLEBINOP 366 367 // Comparisons. 368 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 369 unsigned SICmpOpc, unsigned FCmpOpc); 370#define VISITCOMP(CODE, UI, SI, FP) \ 371 Value *VisitBin##CODE(const BinaryOperator *E) { \ 372 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 373 llvm::FCmpInst::FP); } 374 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT); 375 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT); 376 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE); 377 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE); 378 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ); 379 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE); 380#undef VISITCOMP 381 382 Value *VisitBinAssign (const BinaryOperator *E); 383 384 Value *VisitBinLAnd (const BinaryOperator *E); 385 Value *VisitBinLOr (const BinaryOperator *E); 386 Value *VisitBinComma (const BinaryOperator *E); 387 388 // Other Operators. 389 Value *VisitBlockExpr(const BlockExpr *BE); 390 Value *VisitConditionalOperator(const ConditionalOperator *CO); 391 Value *VisitChooseExpr(ChooseExpr *CE); 392 Value *VisitVAArgExpr(VAArgExpr *VE); 393 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 394 return CGF.EmitObjCStringLiteral(E); 395 } 396}; 397} // end anonymous namespace. 398 399//===----------------------------------------------------------------------===// 400// Utilities 401//===----------------------------------------------------------------------===// 402 403/// EmitConversionToBool - Convert the specified expression value to a 404/// boolean (i1) truth value. This is equivalent to "Val != 0". 405Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 406 assert(SrcType->isCanonical() && "EmitScalarConversion strips typedefs"); 407 408 if (SrcType->isRealFloatingType()) { 409 // Compare against 0.0 for fp scalars. 410 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 411 return Builder.CreateFCmpUNE(Src, Zero, "tobool"); 412 } 413 414 if (SrcType->isMemberPointerType()) { 415 // FIXME: This is ABI specific. 416 417 // Compare against -1. 418 llvm::Value *NegativeOne = llvm::Constant::getAllOnesValue(Src->getType()); 419 return Builder.CreateICmpNE(Src, NegativeOne, "tobool"); 420 } 421 422 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 423 "Unknown scalar type to convert"); 424 425 // Because of the type rules of C, we often end up computing a logical value, 426 // then zero extending it to int, then wanting it as a logical value again. 427 // Optimize this common case. 428 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) { 429 if (ZI->getOperand(0)->getType() == 430 llvm::Type::getInt1Ty(CGF.getLLVMContext())) { 431 Value *Result = ZI->getOperand(0); 432 // If there aren't any more uses, zap the instruction to save space. 433 // Note that there can be more uses, for example if this 434 // is the result of an assignment. 435 if (ZI->use_empty()) 436 ZI->eraseFromParent(); 437 return Result; 438 } 439 } 440 441 // Compare against an integer or pointer null. 442 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 443 return Builder.CreateICmpNE(Src, Zero, "tobool"); 444} 445 446/// EmitScalarConversion - Emit a conversion from the specified type to the 447/// specified destination type, both of which are LLVM scalar types. 448Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 449 QualType DstType) { 450 SrcType = CGF.getContext().getCanonicalType(SrcType); 451 DstType = CGF.getContext().getCanonicalType(DstType); 452 if (SrcType == DstType) return Src; 453 454 if (DstType->isVoidType()) return 0; 455 456 llvm::LLVMContext &VMContext = CGF.getLLVMContext(); 457 458 // Handle conversions to bool first, they are special: comparisons against 0. 459 if (DstType->isBooleanType()) 460 return EmitConversionToBool(Src, SrcType); 461 462 const llvm::Type *DstTy = ConvertType(DstType); 463 464 // Ignore conversions like int -> uint. 465 if (Src->getType() == DstTy) 466 return Src; 467 468 // Handle pointer conversions next: pointers can only be converted to/from 469 // other pointers and integers. Check for pointer types in terms of LLVM, as 470 // some native types (like Obj-C id) may map to a pointer type. 471 if (isa<llvm::PointerType>(DstTy)) { 472 // The source value may be an integer, or a pointer. 473 if (isa<llvm::PointerType>(Src->getType())) 474 return Builder.CreateBitCast(Src, DstTy, "conv"); 475 476 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 477 // First, convert to the correct width so that we control the kind of 478 // extension. 479 const llvm::Type *MiddleTy = 480 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 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->getAsExtVectorType()->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 = 503 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0); 504 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 505 506 // Splat the element across to all elements 507 llvm::SmallVector<llvm::Constant*, 16> Args; 508 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 509 for (unsigned i = 0; i < NumElements; i++) 510 Args.push_back(llvm::ConstantInt::get( 511 llvm::Type::getInt32Ty(VMContext), 0)); 512 513 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 514 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 515 return Yay; 516 } 517 518 // Allow bitcast from vector to integer/fp of the same size. 519 if (isa<llvm::VectorType>(Src->getType()) || 520 isa<llvm::VectorType>(DstTy)) 521 return Builder.CreateBitCast(Src, DstTy, "conv"); 522 523 // Finally, we have the arithmetic types: real int/float. 524 if (isa<llvm::IntegerType>(Src->getType())) { 525 bool InputSigned = SrcType->isSignedIntegerType(); 526 if (isa<llvm::IntegerType>(DstTy)) 527 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 528 else if (InputSigned) 529 return Builder.CreateSIToFP(Src, DstTy, "conv"); 530 else 531 return Builder.CreateUIToFP(Src, DstTy, "conv"); 532 } 533 534 assert(Src->getType()->isFloatingPoint() && "Unknown real conversion"); 535 if (isa<llvm::IntegerType>(DstTy)) { 536 if (DstType->isSignedIntegerType()) 537 return Builder.CreateFPToSI(Src, DstTy, "conv"); 538 else 539 return Builder.CreateFPToUI(Src, DstTy, "conv"); 540 } 541 542 assert(DstTy->isFloatingPoint() && "Unknown real conversion"); 543 if (DstTy->getTypeID() < Src->getType()->getTypeID()) 544 return Builder.CreateFPTrunc(Src, DstTy, "conv"); 545 else 546 return Builder.CreateFPExt(Src, DstTy, "conv"); 547} 548 549/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 550/// type to the specified destination type, where the destination type is an 551/// LLVM scalar type. 552Value *ScalarExprEmitter:: 553EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 554 QualType SrcTy, QualType DstTy) { 555 // Get the source element type. 556 SrcTy = SrcTy->getAsComplexType()->getElementType(); 557 558 // Handle conversions to bool first, they are special: comparisons against 0. 559 if (DstTy->isBooleanType()) { 560 // Complex != 0 -> (Real != 0) | (Imag != 0) 561 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 562 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 563 return Builder.CreateOr(Src.first, Src.second, "tobool"); 564 } 565 566 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 567 // the imaginary part of the complex value is discarded and the value of the 568 // real part is converted according to the conversion rules for the 569 // corresponding real type. 570 return EmitScalarConversion(Src.first, SrcTy, DstTy); 571} 572 573 574//===----------------------------------------------------------------------===// 575// Visitor Methods 576//===----------------------------------------------------------------------===// 577 578Value *ScalarExprEmitter::VisitExpr(Expr *E) { 579 CGF.ErrorUnsupported(E, "scalar expression"); 580 if (E->getType()->isVoidType()) 581 return 0; 582 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 583} 584 585Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 586 llvm::SmallVector<llvm::Constant*, 32> indices; 587 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 588 indices.push_back(cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i)))); 589 } 590 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 591 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 592 Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); 593 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 594} 595 596Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 597 TestAndClearIgnoreResultAssign(); 598 599 // Emit subscript expressions in rvalue context's. For most cases, this just 600 // loads the lvalue formed by the subscript expr. However, we have to be 601 // careful, because the base of a vector subscript is occasionally an rvalue, 602 // so we can't get it as an lvalue. 603 if (!E->getBase()->getType()->isVectorType()) 604 return EmitLoadOfLValue(E); 605 606 // Handle the vector case. The base must be a vector, the index must be an 607 // integer value. 608 Value *Base = Visit(E->getBase()); 609 Value *Idx = Visit(E->getIdx()); 610 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerType(); 611 Idx = Builder.CreateIntCast(Idx, 612 llvm::Type::getInt32Ty(CGF.getLLVMContext()), 613 IdxSigned, 614 "vecidxcast"); 615 return Builder.CreateExtractElement(Base, Idx, "vecext"); 616} 617 618// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 619// have to handle a more broad range of conversions than explicit casts, as they 620// handle things like function to ptr-to-function decay etc. 621Value *ScalarExprEmitter::EmitCastExpr(const Expr *E, QualType DestTy, 622 CastExpr::CastKind Kind) { 623 if (!DestTy->isVoidType()) 624 TestAndClearIgnoreResultAssign(); 625 626 switch (Kind) { 627 default: 628 break; 629 case CastExpr::CK_BitCast: { 630 Value *Src = Visit(const_cast<Expr*>(E)); 631 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 632 } 633 case CastExpr::CK_ArrayToPointerDecay: { 634 assert(E->getType()->isArrayType() && 635 "Array to pointer decay must have array source type!"); 636 637 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 638 639 // Note that VLA pointers are always decayed, so we don't need to do 640 // anything here. 641 if (!E->getType()->isVariableArrayType()) { 642 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 643 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 644 ->getElementType()) && 645 "Expected pointer to array"); 646 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 647 } 648 649 // The resultant pointer type can be implicitly casted to other pointer 650 // types as well (e.g. void*) and can be implicitly converted to integer. 651 const llvm::Type *DestLTy = ConvertType(DestTy); 652 if (V->getType() != DestLTy) { 653 if (isa<llvm::PointerType>(DestLTy)) 654 V = Builder.CreateBitCast(V, DestLTy, "ptrconv"); 655 else { 656 assert(isa<llvm::IntegerType>(DestLTy) && "Unknown array decay"); 657 V = Builder.CreatePtrToInt(V, DestLTy, "ptrconv"); 658 } 659 } 660 return V; 661 } 662 case CastExpr::CK_NullToMemberPointer: 663 return CGF.CGM.EmitNullConstant(DestTy); 664 665 case CastExpr::CK_DerivedToBase: { 666 const RecordType *DerivedClassTy = 667 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 668 CXXRecordDecl *DerivedClassDecl = 669 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 670 671 const RecordType *BaseClassTy = 672 DestTy->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 673 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseClassTy->getDecl()); 674 675 Value *Src = Visit(const_cast<Expr*>(E)); 676 677 // FIXME: This should be true, but that leads to a failure in virt.cpp 678 bool NullCheckValue = false; 679 680 // We always assume that 'this' is never null. 681 if (isa<CXXThisExpr>(E)) 682 NullCheckValue = false; 683 684 return CGF.GetAddressCXXOfBaseClass(Src, DerivedClassDecl, BaseClassDecl, 685 NullCheckValue); 686 } 687 688 } 689 690 // Handle cases where the source is an non-complex type. 691 692 if (!CGF.hasAggregateLLVMType(E->getType())) { 693 Value *Src = Visit(const_cast<Expr*>(E)); 694 695 // Use EmitScalarConversion to perform the conversion. 696 return EmitScalarConversion(Src, E->getType(), DestTy); 697 } 698 699 if (E->getType()->isAnyComplexType()) { 700 // Handle cases where the source is a complex type. 701 bool IgnoreImag = true; 702 bool IgnoreImagAssign = true; 703 bool IgnoreReal = IgnoreResultAssign; 704 bool IgnoreRealAssign = IgnoreResultAssign; 705 if (DestTy->isBooleanType()) 706 IgnoreImagAssign = IgnoreImag = false; 707 else if (DestTy->isVoidType()) { 708 IgnoreReal = IgnoreImag = false; 709 IgnoreRealAssign = IgnoreImagAssign = true; 710 } 711 CodeGenFunction::ComplexPairTy V 712 = CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign, 713 IgnoreImagAssign); 714 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 715 } 716 717 // Okay, this is a cast from an aggregate. It must be a cast to void. Just 718 // evaluate the result and return. 719 CGF.EmitAggExpr(E, 0, false, true); 720 return 0; 721} 722 723Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 724 return CGF.EmitCompoundStmt(*E->getSubStmt(), 725 !E->getType()->isVoidType()).getScalarVal(); 726} 727 728Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 729 return Builder.CreateLoad(CGF.GetAddrOfBlockDecl(E), false, "tmp"); 730} 731 732//===----------------------------------------------------------------------===// 733// Unary Operators 734//===----------------------------------------------------------------------===// 735 736Value *ScalarExprEmitter::VisitPrePostIncDec(const UnaryOperator *E, 737 bool isInc, bool isPre) { 738 LValue LV = EmitLValue(E->getSubExpr()); 739 QualType ValTy = E->getSubExpr()->getType(); 740 Value *InVal = CGF.EmitLoadOfLValue(LV, ValTy).getScalarVal(); 741 742 llvm::LLVMContext &VMContext = CGF.getLLVMContext(); 743 744 int AmountVal = isInc ? 1 : -1; 745 746 if (ValTy->isPointerType() && 747 ValTy->getAs<PointerType>()->isVariableArrayType()) { 748 // The amount of the addition/subtraction needs to account for the VLA size 749 CGF.ErrorUnsupported(E, "VLA pointer inc/dec"); 750 } 751 752 Value *NextVal; 753 if (const llvm::PointerType *PT = 754 dyn_cast<llvm::PointerType>(InVal->getType())) { 755 llvm::Constant *Inc = 756 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), AmountVal); 757 if (!isa<llvm::FunctionType>(PT->getElementType())) { 758 QualType PTEE = ValTy->getPointeeType(); 759 if (const ObjCInterfaceType *OIT = 760 dyn_cast<ObjCInterfaceType>(PTEE)) { 761 // Handle interface types, which are not represented with a concrete type. 762 int size = CGF.getContext().getTypeSize(OIT) / 8; 763 if (!isInc) 764 size = -size; 765 Inc = llvm::ConstantInt::get(Inc->getType(), size); 766 const llvm::Type *i8Ty = 767 llvm::PointerType::getUnqual(llvm::Type::getInt8Ty(VMContext)); 768 InVal = Builder.CreateBitCast(InVal, i8Ty); 769 NextVal = Builder.CreateGEP(InVal, Inc, "add.ptr"); 770 llvm::Value *lhs = LV.getAddress(); 771 lhs = Builder.CreateBitCast(lhs, llvm::PointerType::getUnqual(i8Ty)); 772 LV = LValue::MakeAddr(lhs, ValTy.getCVRQualifiers(), 773 CGF.getContext().getObjCGCAttrKind(ValTy)); 774 } else 775 NextVal = Builder.CreateInBoundsGEP(InVal, Inc, "ptrincdec"); 776 } else { 777 const llvm::Type *i8Ty = 778 llvm::PointerType::getUnqual(llvm::Type::getInt8Ty(VMContext)); 779 NextVal = Builder.CreateBitCast(InVal, i8Ty, "tmp"); 780 NextVal = Builder.CreateGEP(NextVal, Inc, "ptrincdec"); 781 NextVal = Builder.CreateBitCast(NextVal, InVal->getType()); 782 } 783 } else if (InVal->getType() == llvm::Type::getInt1Ty(VMContext) && isInc) { 784 // Bool++ is an interesting case, due to promotion rules, we get: 785 // Bool++ -> Bool = Bool+1 -> Bool = (int)Bool+1 -> 786 // Bool = ((int)Bool+1) != 0 787 // An interesting aspect of this is that increment is always true. 788 // Decrement does not have this property. 789 NextVal = llvm::ConstantInt::getTrue(VMContext); 790 } else if (isa<llvm::IntegerType>(InVal->getType())) { 791 NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); 792 793 // Signed integer overflow is undefined behavior. 794 if (ValTy->isSignedIntegerType()) 795 NextVal = Builder.CreateNSWAdd(InVal, NextVal, isInc ? "inc" : "dec"); 796 else 797 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 798 } else { 799 // Add the inc/dec to the real part. 800 if (InVal->getType() == llvm::Type::getFloatTy(VMContext)) 801 NextVal = 802 llvm::ConstantFP::get(VMContext, 803 llvm::APFloat(static_cast<float>(AmountVal))); 804 else if (InVal->getType() == llvm::Type::getDoubleTy(VMContext)) 805 NextVal = 806 llvm::ConstantFP::get(VMContext, 807 llvm::APFloat(static_cast<double>(AmountVal))); 808 else { 809 llvm::APFloat F(static_cast<float>(AmountVal)); 810 bool ignored; 811 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, 812 &ignored); 813 NextVal = llvm::ConstantFP::get(VMContext, F); 814 } 815 NextVal = Builder.CreateFAdd(InVal, NextVal, isInc ? "inc" : "dec"); 816 } 817 818 // Store the updated result through the lvalue. 819 if (LV.isBitfield()) 820 CGF.EmitStoreThroughBitfieldLValue(RValue::get(NextVal), LV, ValTy, 821 &NextVal); 822 else 823 CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV, ValTy); 824 825 // If this is a postinc, return the value read from memory, otherwise use the 826 // updated value. 827 return isPre ? NextVal : InVal; 828} 829 830 831Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 832 TestAndClearIgnoreResultAssign(); 833 Value *Op = Visit(E->getSubExpr()); 834 if (Op->getType()->isFPOrFPVector()) 835 return Builder.CreateFNeg(Op, "neg"); 836 return Builder.CreateNeg(Op, "neg"); 837} 838 839Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 840 TestAndClearIgnoreResultAssign(); 841 Value *Op = Visit(E->getSubExpr()); 842 return Builder.CreateNot(Op, "neg"); 843} 844 845Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 846 // Compare operand to zero. 847 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 848 849 // Invert value. 850 // TODO: Could dynamically modify easy computations here. For example, if 851 // the operand is an icmp ne, turn into icmp eq. 852 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 853 854 // ZExt result to the expr type. 855 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 856} 857 858/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of 859/// argument of the sizeof expression as an integer. 860Value * 861ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { 862 QualType TypeToSize = E->getTypeOfArgument(); 863 if (E->isSizeOf()) { 864 if (const VariableArrayType *VAT = 865 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 866 if (E->isArgumentType()) { 867 // sizeof(type) - make sure to emit the VLA size. 868 CGF.EmitVLASize(TypeToSize); 869 } else { 870 // C99 6.5.3.4p2: If the argument is an expression of type 871 // VLA, it is evaluated. 872 CGF.EmitAnyExpr(E->getArgumentExpr()); 873 } 874 875 return CGF.GetVLASize(VAT); 876 } 877 } 878 879 // If this isn't sizeof(vla), the result must be constant; use the constant 880 // folding logic so we don't have to duplicate it here. 881 Expr::EvalResult Result; 882 E->Evaluate(Result, CGF.getContext()); 883 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 884} 885 886Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 887 Expr *Op = E->getSubExpr(); 888 if (Op->getType()->isAnyComplexType()) 889 return CGF.EmitComplexExpr(Op, false, true, false, true).first; 890 return Visit(Op); 891} 892Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 893 Expr *Op = E->getSubExpr(); 894 if (Op->getType()->isAnyComplexType()) 895 return CGF.EmitComplexExpr(Op, true, false, true, false).second; 896 897 // __imag on a scalar returns zero. Emit the subexpr to ensure side 898 // effects are evaluated, but not the actual value. 899 if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) 900 CGF.EmitLValue(Op); 901 else 902 CGF.EmitScalarExpr(Op, true); 903 return llvm::Constant::getNullValue(ConvertType(E->getType())); 904} 905 906Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) { 907 Value* ResultAsPtr = EmitLValue(E->getSubExpr()).getAddress(); 908 const llvm::Type* ResultType = ConvertType(E->getType()); 909 return Builder.CreatePtrToInt(ResultAsPtr, ResultType, "offsetof"); 910} 911 912//===----------------------------------------------------------------------===// 913// Binary Operators 914//===----------------------------------------------------------------------===// 915 916BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 917 TestAndClearIgnoreResultAssign(); 918 BinOpInfo Result; 919 Result.LHS = Visit(E->getLHS()); 920 Result.RHS = Visit(E->getRHS()); 921 Result.Ty = E->getType(); 922 Result.E = E; 923 return Result; 924} 925 926Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 927 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 928 bool Ignore = TestAndClearIgnoreResultAssign(); 929 QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType(); 930 931 BinOpInfo OpInfo; 932 933 if (E->getComputationResultType()->isAnyComplexType()) { 934 // This needs to go through the complex expression emitter, but it's a tad 935 // complicated to do that... I'm leaving it out for now. (Note that we do 936 // actually need the imaginary part of the RHS for multiplication and 937 // division.) 938 CGF.ErrorUnsupported(E, "complex compound assignment"); 939 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 940 } 941 942 // Emit the RHS first. __block variables need to have the rhs evaluated 943 // first, plus this should improve codegen a little. 944 OpInfo.RHS = Visit(E->getRHS()); 945 OpInfo.Ty = E->getComputationResultType(); 946 OpInfo.E = E; 947 // Load/convert the LHS. 948 LValue LHSLV = EmitLValue(E->getLHS()); 949 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 950 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 951 E->getComputationLHSType()); 952 953 // Expand the binary operator. 954 Value *Result = (this->*Func)(OpInfo); 955 956 // Convert the result back to the LHS type. 957 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 958 959 // Store the result value into the LHS lvalue. Bit-fields are handled 960 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 961 // 'An assignment expression has the value of the left operand after the 962 // assignment...'. 963 if (LHSLV.isBitfield()) { 964 if (!LHSLV.isVolatileQualified()) { 965 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, 966 &Result); 967 return Result; 968 } else 969 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy); 970 } else 971 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); 972 if (Ignore) 973 return 0; 974 return EmitLoadOfLValue(LHSLV, E->getType()); 975} 976 977 978Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 979 if (Ops.LHS->getType()->isFPOrFPVector()) 980 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 981 else if (Ops.Ty->isUnsignedIntegerType()) 982 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 983 else 984 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 985} 986 987Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 988 // Rem in C can't be a floating point type: C99 6.5.5p2. 989 if (Ops.Ty->isUnsignedIntegerType()) 990 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 991 else 992 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 993} 994 995Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 996 unsigned IID; 997 unsigned OpID = 0; 998 999 switch (Ops.E->getOpcode()) { 1000 case BinaryOperator::Add: 1001 case BinaryOperator::AddAssign: 1002 OpID = 1; 1003 IID = llvm::Intrinsic::sadd_with_overflow; 1004 break; 1005 case BinaryOperator::Sub: 1006 case BinaryOperator::SubAssign: 1007 OpID = 2; 1008 IID = llvm::Intrinsic::ssub_with_overflow; 1009 break; 1010 case BinaryOperator::Mul: 1011 case BinaryOperator::MulAssign: 1012 OpID = 3; 1013 IID = llvm::Intrinsic::smul_with_overflow; 1014 break; 1015 default: 1016 assert(false && "Unsupported operation for overflow detection"); 1017 IID = 0; 1018 } 1019 OpID <<= 1; 1020 OpID |= 1; 1021 1022 const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1023 1024 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1); 1025 1026 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1027 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1028 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1029 1030 // Branch in case of overflow. 1031 llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); 1032 llvm::BasicBlock *overflowBB = 1033 CGF.createBasicBlock("overflow", CGF.CurFn); 1034 llvm::BasicBlock *continueBB = 1035 CGF.createBasicBlock("overflow.continue", CGF.CurFn); 1036 1037 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1038 1039 // Handle overflow 1040 1041 Builder.SetInsertPoint(overflowBB); 1042 1043 // Handler is: 1044 // long long *__overflow_handler)(long long a, long long b, char op, 1045 // char width) 1046 std::vector<const llvm::Type*> handerArgTypes; 1047 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1048 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1049 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1050 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1051 llvm::FunctionType *handlerTy = llvm::FunctionType::get( 1052 llvm::Type::getInt64Ty(VMContext), handerArgTypes, false); 1053 llvm::Value *handlerFunction = 1054 CGF.CGM.getModule().getOrInsertGlobal("__overflow_handler", 1055 llvm::PointerType::getUnqual(handlerTy)); 1056 handlerFunction = Builder.CreateLoad(handlerFunction); 1057 1058 llvm::Value *handlerResult = Builder.CreateCall4(handlerFunction, 1059 Builder.CreateSExt(Ops.LHS, llvm::Type::getInt64Ty(VMContext)), 1060 Builder.CreateSExt(Ops.RHS, llvm::Type::getInt64Ty(VMContext)), 1061 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), OpID), 1062 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), 1063 cast<llvm::IntegerType>(opTy)->getBitWidth())); 1064 1065 handlerResult = Builder.CreateTrunc(handlerResult, opTy); 1066 1067 Builder.CreateBr(continueBB); 1068 1069 // Set up the continuation 1070 Builder.SetInsertPoint(continueBB); 1071 // Get the correct result 1072 llvm::PHINode *phi = Builder.CreatePHI(opTy); 1073 phi->reserveOperandSpace(2); 1074 phi->addIncoming(result, initialBB); 1075 phi->addIncoming(handlerResult, overflowBB); 1076 1077 return phi; 1078} 1079 1080Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 1081 if (!Ops.Ty->isAnyPointerType()) { 1082 if (CGF.getContext().getLangOptions().OverflowChecking && 1083 Ops.Ty->isSignedIntegerType()) 1084 return EmitOverflowCheckedBinOp(Ops); 1085 1086 if (Ops.LHS->getType()->isFPOrFPVector()) 1087 return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add"); 1088 1089 // Signed integer overflow is undefined behavior. 1090 if (Ops.Ty->isSignedIntegerType()) 1091 return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add"); 1092 1093 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1094 } 1095 1096 if (Ops.Ty->isPointerType() && 1097 Ops.Ty->getAs<PointerType>()->isVariableArrayType()) { 1098 // The amount of the addition needs to account for the VLA size 1099 CGF.ErrorUnsupported(Ops.E, "VLA pointer addition"); 1100 } 1101 Value *Ptr, *Idx; 1102 Expr *IdxExp; 1103 const PointerType *PT = Ops.E->getLHS()->getType()->getAs<PointerType>(); 1104 const ObjCObjectPointerType *OPT = 1105 Ops.E->getLHS()->getType()->getAsObjCObjectPointerType(); 1106 if (PT || OPT) { 1107 Ptr = Ops.LHS; 1108 Idx = Ops.RHS; 1109 IdxExp = Ops.E->getRHS(); 1110 } else { // int + pointer 1111 PT = Ops.E->getRHS()->getType()->getAs<PointerType>(); 1112 OPT = Ops.E->getRHS()->getType()->getAsObjCObjectPointerType(); 1113 assert((PT || OPT) && "Invalid add expr"); 1114 Ptr = Ops.RHS; 1115 Idx = Ops.LHS; 1116 IdxExp = Ops.E->getLHS(); 1117 } 1118 1119 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1120 if (Width < CGF.LLVMPointerWidth) { 1121 // Zero or sign extend the pointer value based on whether the index is 1122 // signed or not. 1123 const llvm::Type *IdxType = 1124 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1125 if (IdxExp->getType()->isSignedIntegerType()) 1126 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1127 else 1128 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1129 } 1130 const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType(); 1131 // Handle interface types, which are not represented with a concrete type. 1132 if (const ObjCInterfaceType *OIT = dyn_cast<ObjCInterfaceType>(ElementType)) { 1133 llvm::Value *InterfaceSize = 1134 llvm::ConstantInt::get(Idx->getType(), 1135 CGF.getContext().getTypeSize(OIT) / 8); 1136 Idx = Builder.CreateMul(Idx, InterfaceSize); 1137 const llvm::Type *i8Ty = 1138 llvm::PointerType::getUnqual(llvm::Type::getInt8Ty(VMContext)); 1139 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1140 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1141 return Builder.CreateBitCast(Res, Ptr->getType()); 1142 } 1143 1144 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 1145 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 1146 // future proof. 1147 if (ElementType->isVoidType() || ElementType->isFunctionType()) { 1148 const llvm::Type *i8Ty = 1149 llvm::PointerType::getUnqual(llvm::Type::getInt8Ty(VMContext)); 1150 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1151 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1152 return Builder.CreateBitCast(Res, Ptr->getType()); 1153 } 1154 1155 return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr"); 1156} 1157 1158Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 1159 if (!isa<llvm::PointerType>(Ops.LHS->getType())) { 1160 if (CGF.getContext().getLangOptions().OverflowChecking 1161 && Ops.Ty->isSignedIntegerType()) 1162 return EmitOverflowCheckedBinOp(Ops); 1163 1164 if (Ops.LHS->getType()->isFPOrFPVector()) 1165 return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub"); 1166 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1167 } 1168 1169 if (Ops.E->getLHS()->getType()->isPointerType() && 1170 Ops.E->getLHS()->getType()->getAs<PointerType>()->isVariableArrayType()) { 1171 // The amount of the addition needs to account for the VLA size for 1172 // ptr-int 1173 // The amount of the division needs to account for the VLA size for 1174 // ptr-ptr. 1175 CGF.ErrorUnsupported(Ops.E, "VLA pointer subtraction"); 1176 } 1177 1178 const QualType LHSType = Ops.E->getLHS()->getType(); 1179 const QualType LHSElementType = LHSType->getPointeeType(); 1180 if (!isa<llvm::PointerType>(Ops.RHS->getType())) { 1181 // pointer - int 1182 Value *Idx = Ops.RHS; 1183 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1184 if (Width < CGF.LLVMPointerWidth) { 1185 // Zero or sign extend the pointer value based on whether the index is 1186 // signed or not. 1187 const llvm::Type *IdxType = 1188 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1189 if (Ops.E->getRHS()->getType()->isSignedIntegerType()) 1190 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1191 else 1192 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1193 } 1194 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); 1195 1196 // Handle interface types, which are not represented with a concrete type. 1197 if (const ObjCInterfaceType *OIT = 1198 dyn_cast<ObjCInterfaceType>(LHSElementType)) { 1199 llvm::Value *InterfaceSize = 1200 llvm::ConstantInt::get(Idx->getType(), 1201 CGF.getContext().getTypeSize(OIT) / 8); 1202 Idx = Builder.CreateMul(Idx, InterfaceSize); 1203 const llvm::Type *i8Ty = 1204 llvm::PointerType::getUnqual(llvm::Type::getInt8Ty(VMContext)); 1205 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1206 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr"); 1207 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1208 } 1209 1210 // Explicitly handle GNU void* and function pointer arithmetic 1211 // extensions. The GNU void* casts amount to no-ops since our void* type is 1212 // i8*, but this is future proof. 1213 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1214 const llvm::Type *i8Ty = 1215 llvm::PointerType::getUnqual(llvm::Type::getInt8Ty(VMContext)); 1216 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1217 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); 1218 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1219 } 1220 1221 return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr"); 1222 } else { 1223 // pointer - pointer 1224 Value *LHS = Ops.LHS; 1225 Value *RHS = Ops.RHS; 1226 1227 uint64_t ElementSize; 1228 1229 // Handle GCC extension for pointer arithmetic on void* and function pointer 1230 // types. 1231 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1232 ElementSize = 1; 1233 } else { 1234 ElementSize = CGF.getContext().getTypeSize(LHSElementType) / 8; 1235 } 1236 1237 const llvm::Type *ResultType = ConvertType(Ops.Ty); 1238 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 1239 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 1240 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 1241 1242 // Optimize out the shift for element size of 1. 1243 if (ElementSize == 1) 1244 return BytesBetween; 1245 1246 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 1247 // pointer difference in C is only defined in the case where both operands 1248 // are pointing to elements of an array. 1249 Value *BytesPerElt = llvm::ConstantInt::get(ResultType, ElementSize); 1250 return Builder.CreateExactSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 1251 } 1252} 1253 1254Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 1255 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1256 // RHS to the same size as the LHS. 1257 Value *RHS = Ops.RHS; 1258 if (Ops.LHS->getType() != RHS->getType()) 1259 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1260 1261 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 1262} 1263 1264Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 1265 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1266 // RHS to the same size as the LHS. 1267 Value *RHS = Ops.RHS; 1268 if (Ops.LHS->getType() != RHS->getType()) 1269 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1270 1271 if (Ops.Ty->isUnsignedIntegerType()) 1272 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 1273 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 1274} 1275 1276Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 1277 unsigned SICmpOpc, unsigned FCmpOpc) { 1278 TestAndClearIgnoreResultAssign(); 1279 Value *Result; 1280 QualType LHSTy = E->getLHS()->getType(); 1281 if (!LHSTy->isAnyComplexType()) { 1282 Value *LHS = Visit(E->getLHS()); 1283 Value *RHS = Visit(E->getRHS()); 1284 1285 if (LHS->getType()->isFPOrFPVector()) { 1286 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 1287 LHS, RHS, "cmp"); 1288 } else if (LHSTy->isSignedIntegerType()) { 1289 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 1290 LHS, RHS, "cmp"); 1291 } else { 1292 // Unsigned integers and pointers. 1293 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1294 LHS, RHS, "cmp"); 1295 } 1296 1297 // If this is a vector comparison, sign extend the result to the appropriate 1298 // vector integer type and return it (don't convert to bool). 1299 if (LHSTy->isVectorType()) 1300 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 1301 1302 } else { 1303 // Complex Comparison: can only be an equality comparison. 1304 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 1305 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 1306 1307 QualType CETy = LHSTy->getAsComplexType()->getElementType(); 1308 1309 Value *ResultR, *ResultI; 1310 if (CETy->isRealFloatingType()) { 1311 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1312 LHS.first, RHS.first, "cmp.r"); 1313 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1314 LHS.second, RHS.second, "cmp.i"); 1315 } else { 1316 // Complex comparisons can only be equality comparisons. As such, signed 1317 // and unsigned opcodes are the same. 1318 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1319 LHS.first, RHS.first, "cmp.r"); 1320 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1321 LHS.second, RHS.second, "cmp.i"); 1322 } 1323 1324 if (E->getOpcode() == BinaryOperator::EQ) { 1325 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 1326 } else { 1327 assert(E->getOpcode() == BinaryOperator::NE && 1328 "Complex comparison other than == or != ?"); 1329 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 1330 } 1331 } 1332 1333 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 1334} 1335 1336Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 1337 bool Ignore = TestAndClearIgnoreResultAssign(); 1338 1339 // __block variables need to have the rhs evaluated first, plus this should 1340 // improve codegen just a little. 1341 Value *RHS = Visit(E->getRHS()); 1342 LValue LHS = EmitLValue(E->getLHS()); 1343 1344 // Store the value into the LHS. Bit-fields are handled specially 1345 // because the result is altered by the store, i.e., [C99 6.5.16p1] 1346 // 'An assignment expression has the value of the left operand after 1347 // the assignment...'. 1348 if (LHS.isBitfield()) { 1349 if (!LHS.isVolatileQualified()) { 1350 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), 1351 &RHS); 1352 return RHS; 1353 } else 1354 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType()); 1355 } else 1356 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 1357 if (Ignore) 1358 return 0; 1359 return EmitLoadOfLValue(LHS, E->getType()); 1360} 1361 1362Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 1363 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 1364 // If we have 1 && X, just emit X without inserting the control flow. 1365 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1366 if (Cond == 1) { // If we have 1 && X, just emit X. 1367 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1368 // ZExt result to int. 1369 return Builder.CreateZExt(RHSCond, CGF.LLVMIntTy, "land.ext"); 1370 } 1371 1372 // 0 && RHS: If it is safe, just elide the RHS, and return 0. 1373 if (!CGF.ContainsLabel(E->getRHS())) 1374 return llvm::Constant::getNullValue(CGF.LLVMIntTy); 1375 } 1376 1377 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 1378 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 1379 1380 // Branch on the LHS first. If it is false, go to the failure (cont) block. 1381 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 1382 1383 // Any edges into the ContBlock are now from an (indeterminate number of) 1384 // edges from this first condition. All of these values will be false. Start 1385 // setting up the PHI node in the Cont Block for this. 1386 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1387 "", ContBlock); 1388 PN->reserveOperandSpace(2); // Normal case, two inputs. 1389 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1390 PI != PE; ++PI) 1391 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 1392 1393 CGF.PushConditionalTempDestruction(); 1394 CGF.EmitBlock(RHSBlock); 1395 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1396 CGF.PopConditionalTempDestruction(); 1397 1398 // Reaquire the RHS block, as there may be subblocks inserted. 1399 RHSBlock = Builder.GetInsertBlock(); 1400 1401 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1402 // into the phi node for the edge with the value of RHSCond. 1403 CGF.EmitBlock(ContBlock); 1404 PN->addIncoming(RHSCond, RHSBlock); 1405 1406 // ZExt result to int. 1407 return Builder.CreateZExt(PN, CGF.LLVMIntTy, "land.ext"); 1408} 1409 1410Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 1411 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 1412 // If we have 0 || X, just emit X without inserting the control flow. 1413 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1414 if (Cond == -1) { // If we have 0 || X, just emit X. 1415 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1416 // ZExt result to int. 1417 return Builder.CreateZExt(RHSCond, CGF.LLVMIntTy, "lor.ext"); 1418 } 1419 1420 // 1 || RHS: If it is safe, just elide the RHS, and return 1. 1421 if (!CGF.ContainsLabel(E->getRHS())) 1422 return llvm::ConstantInt::get(CGF.LLVMIntTy, 1); 1423 } 1424 1425 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 1426 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 1427 1428 // Branch on the LHS first. If it is true, go to the success (cont) block. 1429 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 1430 1431 // Any edges into the ContBlock are now from an (indeterminate number of) 1432 // edges from this first condition. All of these values will be true. Start 1433 // setting up the PHI node in the Cont Block for this. 1434 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1435 "", ContBlock); 1436 PN->reserveOperandSpace(2); // Normal case, two inputs. 1437 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1438 PI != PE; ++PI) 1439 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 1440 1441 CGF.PushConditionalTempDestruction(); 1442 1443 // Emit the RHS condition as a bool value. 1444 CGF.EmitBlock(RHSBlock); 1445 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1446 1447 CGF.PopConditionalTempDestruction(); 1448 1449 // Reaquire the RHS block, as there may be subblocks inserted. 1450 RHSBlock = Builder.GetInsertBlock(); 1451 1452 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1453 // into the phi node for the edge with the value of RHSCond. 1454 CGF.EmitBlock(ContBlock); 1455 PN->addIncoming(RHSCond, RHSBlock); 1456 1457 // ZExt result to int. 1458 return Builder.CreateZExt(PN, CGF.LLVMIntTy, "lor.ext"); 1459} 1460 1461Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 1462 CGF.EmitStmt(E->getLHS()); 1463 CGF.EnsureInsertPoint(); 1464 return Visit(E->getRHS()); 1465} 1466 1467//===----------------------------------------------------------------------===// 1468// Other Operators 1469//===----------------------------------------------------------------------===// 1470 1471/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 1472/// expression is cheap enough and side-effect-free enough to evaluate 1473/// unconditionally instead of conditionally. This is used to convert control 1474/// flow into selects in some cases. 1475static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E) { 1476 if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) 1477 return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr()); 1478 1479 // TODO: Allow anything we can constant fold to an integer or fp constant. 1480 if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || 1481 isa<FloatingLiteral>(E)) 1482 return true; 1483 1484 // Non-volatile automatic variables too, to get "cond ? X : Y" where 1485 // X and Y are local variables. 1486 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 1487 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 1488 if (VD->hasLocalStorage() && !VD->getType().isVolatileQualified()) 1489 return true; 1490 1491 return false; 1492} 1493 1494 1495Value *ScalarExprEmitter:: 1496VisitConditionalOperator(const ConditionalOperator *E) { 1497 TestAndClearIgnoreResultAssign(); 1498 // If the condition constant folds and can be elided, try to avoid emitting 1499 // the condition and the dead arm. 1500 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ 1501 Expr *Live = E->getLHS(), *Dead = E->getRHS(); 1502 if (Cond == -1) 1503 std::swap(Live, Dead); 1504 1505 // If the dead side doesn't have labels we need, and if the Live side isn't 1506 // the gnu missing ?: extension (which we could handle, but don't bother 1507 // to), just emit the Live part. 1508 if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part 1509 Live) // Live part isn't missing. 1510 return Visit(Live); 1511 } 1512 1513 1514 // If this is a really simple expression (like x ? 4 : 5), emit this as a 1515 // select instead of as control flow. We can only do this if it is cheap and 1516 // safe to evaluate the LHS and RHS unconditionally. 1517 if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS()) && 1518 isCheapEnoughToEvaluateUnconditionally(E->getRHS())) { 1519 llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); 1520 llvm::Value *LHS = Visit(E->getLHS()); 1521 llvm::Value *RHS = Visit(E->getRHS()); 1522 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 1523 } 1524 1525 1526 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 1527 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 1528 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 1529 Value *CondVal = 0; 1530 1531 // If we don't have the GNU missing condition extension, emit a branch on bool 1532 // the normal way. 1533 if (E->getLHS()) { 1534 // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for 1535 // the branch on bool. 1536 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); 1537 } else { 1538 // Otherwise, for the ?: extension, evaluate the conditional and then 1539 // convert it to bool the hard way. We do this explicitly because we need 1540 // the unconverted value for the missing middle value of the ?:. 1541 CondVal = CGF.EmitScalarExpr(E->getCond()); 1542 1543 // In some cases, EmitScalarConversion will delete the "CondVal" expression 1544 // if there are no extra uses (an optimization). Inhibit this by making an 1545 // extra dead use, because we're going to add a use of CondVal later. We 1546 // don't use the builder for this, because we don't want it to get optimized 1547 // away. This leaves dead code, but the ?: extension isn't common. 1548 new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", 1549 Builder.GetInsertBlock()); 1550 1551 Value *CondBoolVal = 1552 CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 1553 CGF.getContext().BoolTy); 1554 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 1555 } 1556 1557 CGF.PushConditionalTempDestruction(); 1558 CGF.EmitBlock(LHSBlock); 1559 1560 // Handle the GNU extension for missing LHS. 1561 Value *LHS; 1562 if (E->getLHS()) 1563 LHS = Visit(E->getLHS()); 1564 else // Perform promotions, to handle cases like "short ?: int" 1565 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); 1566 1567 CGF.PopConditionalTempDestruction(); 1568 LHSBlock = Builder.GetInsertBlock(); 1569 CGF.EmitBranch(ContBlock); 1570 1571 CGF.PushConditionalTempDestruction(); 1572 CGF.EmitBlock(RHSBlock); 1573 1574 Value *RHS = Visit(E->getRHS()); 1575 CGF.PopConditionalTempDestruction(); 1576 RHSBlock = Builder.GetInsertBlock(); 1577 CGF.EmitBranch(ContBlock); 1578 1579 CGF.EmitBlock(ContBlock); 1580 1581 if (!LHS || !RHS) { 1582 assert(E->getType()->isVoidType() && "Non-void value should have a value"); 1583 return 0; 1584 } 1585 1586 // Create a PHI node for the real part. 1587 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 1588 PN->reserveOperandSpace(2); 1589 PN->addIncoming(LHS, LHSBlock); 1590 PN->addIncoming(RHS, RHSBlock); 1591 return PN; 1592} 1593 1594Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 1595 return Visit(E->getChosenSubExpr(CGF.getContext())); 1596} 1597 1598Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 1599 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 1600 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 1601 1602 // If EmitVAArg fails, we fall back to the LLVM instruction. 1603 if (!ArgPtr) 1604 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 1605 1606 // FIXME Volatility. 1607 return Builder.CreateLoad(ArgPtr); 1608} 1609 1610Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { 1611 return CGF.BuildBlockLiteralTmp(BE); 1612} 1613 1614//===----------------------------------------------------------------------===// 1615// Entry Point into this File 1616//===----------------------------------------------------------------------===// 1617 1618/// EmitScalarExpr - Emit the computation of the specified expression of scalar 1619/// type, ignoring the result. 1620Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 1621 assert(E && !hasAggregateLLVMType(E->getType()) && 1622 "Invalid scalar expression to emit"); 1623 1624 return ScalarExprEmitter(*this, IgnoreResultAssign) 1625 .Visit(const_cast<Expr*>(E)); 1626} 1627 1628/// EmitScalarConversion - Emit a conversion from the specified type to the 1629/// specified destination type, both of which are LLVM scalar types. 1630Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 1631 QualType DstTy) { 1632 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 1633 "Invalid scalar expression to emit"); 1634 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 1635} 1636 1637/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 1638/// type to the specified destination type, where the destination type is an 1639/// LLVM scalar type. 1640Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 1641 QualType SrcTy, 1642 QualType DstTy) { 1643 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 1644 "Invalid complex -> scalar conversion"); 1645 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 1646 DstTy); 1647} 1648 1649Value *CodeGenFunction::EmitShuffleVector(Value* V1, Value *V2, ...) { 1650 assert(V1->getType() == V2->getType() && 1651 "Vector operands must be of the same type"); 1652 unsigned NumElements = 1653 cast<llvm::VectorType>(V1->getType())->getNumElements(); 1654 1655 va_list va; 1656 va_start(va, V2); 1657 1658 llvm::SmallVector<llvm::Constant*, 16> Args; 1659 for (unsigned i = 0; i < NumElements; i++) { 1660 int n = va_arg(va, int); 1661 assert(n >= 0 && n < (int)NumElements * 2 && 1662 "Vector shuffle index out of bounds!"); 1663 Args.push_back(llvm::ConstantInt::get( 1664 llvm::Type::getInt32Ty(VMContext), n)); 1665 } 1666 1667 const char *Name = va_arg(va, const char *); 1668 va_end(va); 1669 1670 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 1671 1672 return Builder.CreateShuffleVector(V1, V2, Mask, Name); 1673} 1674 1675llvm::Value *CodeGenFunction::EmitVector(llvm::Value * const *Vals, 1676 unsigned NumVals, bool isSplat) { 1677 llvm::Value *Vec 1678 = llvm::UndefValue::get(llvm::VectorType::get(Vals[0]->getType(), NumVals)); 1679 1680 for (unsigned i = 0, e = NumVals; i != e; ++i) { 1681 llvm::Value *Val = isSplat ? Vals[0] : Vals[i]; 1682 llvm::Value *Idx = llvm::ConstantInt::get( 1683 llvm::Type::getInt32Ty(VMContext), i); 1684 Vec = Builder.CreateInsertElement(Vec, Val, Idx, "tmp"); 1685 } 1686 1687 return Vec; 1688} 1689