CGExprScalar.cpp revision 208600
1//===--- CGExprScalar.cpp - Emit LLVM Code for Scalar Exprs ---------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This contains code to emit Expr nodes with scalar LLVM types as LLVM code. 11// 12//===----------------------------------------------------------------------===// 13 14#include "CodeGenFunction.h" 15#include "CGObjCRuntime.h" 16#include "CodeGenModule.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/AST/DeclObjC.h" 19#include "clang/AST/RecordLayout.h" 20#include "clang/AST/StmtVisitor.h" 21#include "clang/Basic/TargetInfo.h" 22#include "llvm/Constants.h" 23#include "llvm/Function.h" 24#include "llvm/GlobalVariable.h" 25#include "llvm/Intrinsics.h" 26#include "llvm/Module.h" 27#include "llvm/Support/CFG.h" 28#include "llvm/Target/TargetData.h" 29#include <cstdarg> 30 31using namespace clang; 32using namespace CodeGen; 33using llvm::Value; 34 35//===----------------------------------------------------------------------===// 36// Scalar Expression Emitter 37//===----------------------------------------------------------------------===// 38 39struct BinOpInfo { 40 Value *LHS; 41 Value *RHS; 42 QualType Ty; // Computation Type. 43 const BinaryOperator *E; 44}; 45 46namespace { 47class 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 LValue EmitCheckedLValue(const Expr *E) { return CGF.EmitCheckedLValue(E); } 73 74 Value *EmitLoadOfLValue(LValue LV, QualType T) { 75 return CGF.EmitLoadOfLValue(LV, T).getScalarVal(); 76 } 77 78 /// EmitLoadOfLValue - Given an expression with complex type that represents a 79 /// value l-value, this method emits the address of the l-value, then loads 80 /// and returns the result. 81 Value *EmitLoadOfLValue(const Expr *E) { 82 return EmitLoadOfLValue(EmitCheckedLValue(E), E->getType()); 83 } 84 85 /// EmitConversionToBool - Convert the specified expression value to a 86 /// boolean (i1) truth value. This is equivalent to "Val != 0". 87 Value *EmitConversionToBool(Value *Src, QualType DstTy); 88 89 /// EmitScalarConversion - Emit a conversion from the specified type to the 90 /// specified destination type, both of which are LLVM scalar types. 91 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); 92 93 /// EmitComplexToScalarConversion - Emit a conversion from the specified 94 /// complex type to the specified destination type, where the destination type 95 /// is an LLVM scalar type. 96 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 97 QualType SrcTy, QualType DstTy); 98 99 /// EmitNullValue - Emit a value that corresponds to null for the given type. 100 Value *EmitNullValue(QualType Ty); 101 102 //===--------------------------------------------------------------------===// 103 // Visitor Methods 104 //===--------------------------------------------------------------------===// 105 106 Value *VisitStmt(Stmt *S) { 107 S->dump(CGF.getContext().getSourceManager()); 108 assert(0 && "Stmt can't have complex result type!"); 109 return 0; 110 } 111 Value *VisitExpr(Expr *S); 112 113 Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); } 114 115 // Leaves. 116 Value *VisitIntegerLiteral(const IntegerLiteral *E) { 117 return llvm::ConstantInt::get(VMContext, E->getValue()); 118 } 119 Value *VisitFloatingLiteral(const FloatingLiteral *E) { 120 return llvm::ConstantFP::get(VMContext, E->getValue()); 121 } 122 Value *VisitCharacterLiteral(const CharacterLiteral *E) { 123 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 124 } 125 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 126 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 127 } 128 Value *VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) { 129 return EmitNullValue(E->getType()); 130 } 131 Value *VisitGNUNullExpr(const GNUNullExpr *E) { 132 return EmitNullValue(E->getType()); 133 } 134 Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { 135 return llvm::ConstantInt::get(ConvertType(E->getType()), 136 CGF.getContext().typesAreCompatible( 137 E->getArgType1(), E->getArgType2())); 138 } 139 Value *VisitOffsetOfExpr(const OffsetOfExpr *E); 140 Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); 141 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 142 llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel()); 143 return Builder.CreateBitCast(V, ConvertType(E->getType())); 144 } 145 146 // l-values. 147 Value *VisitDeclRefExpr(DeclRefExpr *E) { 148 Expr::EvalResult Result; 149 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 150 assert(!Result.HasSideEffects && "Constant declref with side-effect?!"); 151 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 152 } 153 return EmitLoadOfLValue(E); 154 } 155 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 156 return CGF.EmitObjCSelectorExpr(E); 157 } 158 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 159 return CGF.EmitObjCProtocolExpr(E); 160 } 161 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 162 return EmitLoadOfLValue(E); 163 } 164 Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { 165 return EmitLoadOfLValue(E); 166 } 167 Value *VisitObjCImplicitSetterGetterRefExpr( 168 ObjCImplicitSetterGetterRefExpr *E) { 169 return EmitLoadOfLValue(E); 170 } 171 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 172 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 173 } 174 175 Value *VisitObjCIsaExpr(ObjCIsaExpr *E) { 176 LValue LV = CGF.EmitObjCIsaExpr(E); 177 Value *V = CGF.EmitLoadOfLValue(LV, E->getType()).getScalarVal(); 178 return V; 179 } 180 181 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 182 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 183 Value *VisitMemberExpr(MemberExpr *E); 184 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 185 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 186 return EmitLoadOfLValue(E); 187 } 188 189 Value *VisitInitListExpr(InitListExpr *E); 190 191 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { 192 return CGF.CGM.EmitNullConstant(E->getType()); 193 } 194 Value *VisitCastExpr(CastExpr *E) { 195 // Make sure to evaluate VLA bounds now so that we have them for later. 196 if (E->getType()->isVariablyModifiedType()) 197 CGF.EmitVLASize(E->getType()); 198 199 return EmitCastExpr(E); 200 } 201 Value *EmitCastExpr(CastExpr *E); 202 203 Value *VisitCallExpr(const CallExpr *E) { 204 if (E->getCallReturnType()->isReferenceType()) 205 return EmitLoadOfLValue(E); 206 207 return CGF.EmitCallExpr(E).getScalarVal(); 208 } 209 210 Value *VisitStmtExpr(const StmtExpr *E); 211 212 Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E); 213 214 // Unary Operators. 215 Value *VisitPrePostIncDec(const UnaryOperator *E, bool isInc, bool isPre) { 216 LValue LV = EmitLValue(E->getSubExpr()); 217 return CGF.EmitScalarPrePostIncDec(E, LV, isInc, isPre); 218 } 219 Value *VisitUnaryPostDec(const UnaryOperator *E) { 220 return VisitPrePostIncDec(E, false, false); 221 } 222 Value *VisitUnaryPostInc(const UnaryOperator *E) { 223 return VisitPrePostIncDec(E, true, false); 224 } 225 Value *VisitUnaryPreDec(const UnaryOperator *E) { 226 return VisitPrePostIncDec(E, false, true); 227 } 228 Value *VisitUnaryPreInc(const UnaryOperator *E) { 229 return VisitPrePostIncDec(E, true, true); 230 } 231 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 232 return EmitLValue(E->getSubExpr()).getAddress(); 233 } 234 Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } 235 Value *VisitUnaryPlus(const UnaryOperator *E) { 236 // This differs from gcc, though, most likely due to a bug in gcc. 237 TestAndClearIgnoreResultAssign(); 238 return Visit(E->getSubExpr()); 239 } 240 Value *VisitUnaryMinus (const UnaryOperator *E); 241 Value *VisitUnaryNot (const UnaryOperator *E); 242 Value *VisitUnaryLNot (const UnaryOperator *E); 243 Value *VisitUnaryReal (const UnaryOperator *E); 244 Value *VisitUnaryImag (const UnaryOperator *E); 245 Value *VisitUnaryExtension(const UnaryOperator *E) { 246 return Visit(E->getSubExpr()); 247 } 248 Value *VisitUnaryOffsetOf(const UnaryOperator *E); 249 250 // C++ 251 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 252 return Visit(DAE->getExpr()); 253 } 254 Value *VisitCXXThisExpr(CXXThisExpr *TE) { 255 return CGF.LoadCXXThis(); 256 } 257 258 Value *VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) { 259 return CGF.EmitCXXExprWithTemporaries(E).getScalarVal(); 260 } 261 Value *VisitCXXNewExpr(const CXXNewExpr *E) { 262 return CGF.EmitCXXNewExpr(E); 263 } 264 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { 265 CGF.EmitCXXDeleteExpr(E); 266 return 0; 267 } 268 Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) { 269 return llvm::ConstantInt::get(Builder.getInt1Ty(), 270 E->EvaluateTrait(CGF.getContext())); 271 } 272 273 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { 274 // C++ [expr.pseudo]p1: 275 // The result shall only be used as the operand for the function call 276 // operator (), and the result of such a call has type void. The only 277 // effect is the evaluation of the postfix-expression before the dot or 278 // arrow. 279 CGF.EmitScalarExpr(E->getBase()); 280 return 0; 281 } 282 283 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { 284 return EmitNullValue(E->getType()); 285 } 286 287 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { 288 CGF.EmitCXXThrowExpr(E); 289 return 0; 290 } 291 292 // Binary Operators. 293 Value *EmitMul(const BinOpInfo &Ops) { 294 if (CGF.getContext().getLangOptions().OverflowChecking 295 && Ops.Ty->isSignedIntegerType()) 296 return EmitOverflowCheckedBinOp(Ops); 297 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 298 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 299 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 300 } 301 /// Create a binary op that checks for overflow. 302 /// Currently only supports +, - and *. 303 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 304 Value *EmitDiv(const BinOpInfo &Ops); 305 Value *EmitRem(const BinOpInfo &Ops); 306 Value *EmitAdd(const BinOpInfo &Ops); 307 Value *EmitSub(const BinOpInfo &Ops); 308 Value *EmitShl(const BinOpInfo &Ops); 309 Value *EmitShr(const BinOpInfo &Ops); 310 Value *EmitAnd(const BinOpInfo &Ops) { 311 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 312 } 313 Value *EmitXor(const BinOpInfo &Ops) { 314 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 315 } 316 Value *EmitOr (const BinOpInfo &Ops) { 317 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 318 } 319 320 BinOpInfo EmitBinOps(const BinaryOperator *E); 321 LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E, 322 Value *(ScalarExprEmitter::*F)(const BinOpInfo &), 323 Value *&BitFieldResult); 324 325 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 326 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 327 328 // Binary operators and binary compound assignment operators. 329#define HANDLEBINOP(OP) \ 330 Value *VisitBin ## OP(const BinaryOperator *E) { \ 331 return Emit ## OP(EmitBinOps(E)); \ 332 } \ 333 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 334 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 335 } 336 HANDLEBINOP(Mul) 337 HANDLEBINOP(Div) 338 HANDLEBINOP(Rem) 339 HANDLEBINOP(Add) 340 HANDLEBINOP(Sub) 341 HANDLEBINOP(Shl) 342 HANDLEBINOP(Shr) 343 HANDLEBINOP(And) 344 HANDLEBINOP(Xor) 345 HANDLEBINOP(Or) 346#undef HANDLEBINOP 347 348 // Comparisons. 349 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 350 unsigned SICmpOpc, unsigned FCmpOpc); 351#define VISITCOMP(CODE, UI, SI, FP) \ 352 Value *VisitBin##CODE(const BinaryOperator *E) { \ 353 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 354 llvm::FCmpInst::FP); } 355 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT) 356 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT) 357 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE) 358 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE) 359 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ) 360 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE) 361#undef VISITCOMP 362 363 Value *VisitBinAssign (const BinaryOperator *E); 364 365 Value *VisitBinLAnd (const BinaryOperator *E); 366 Value *VisitBinLOr (const BinaryOperator *E); 367 Value *VisitBinComma (const BinaryOperator *E); 368 369 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } 370 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); } 371 372 // Other Operators. 373 Value *VisitBlockExpr(const BlockExpr *BE); 374 Value *VisitConditionalOperator(const ConditionalOperator *CO); 375 Value *VisitChooseExpr(ChooseExpr *CE); 376 Value *VisitVAArgExpr(VAArgExpr *VE); 377 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 378 return CGF.EmitObjCStringLiteral(E); 379 } 380}; 381} // end anonymous namespace. 382 383//===----------------------------------------------------------------------===// 384// Utilities 385//===----------------------------------------------------------------------===// 386 387/// EmitConversionToBool - Convert the specified expression value to a 388/// boolean (i1) truth value. This is equivalent to "Val != 0". 389Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 390 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs"); 391 392 if (SrcType->isRealFloatingType()) { 393 // Compare against 0.0 for fp scalars. 394 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 395 return Builder.CreateFCmpUNE(Src, Zero, "tobool"); 396 } 397 398 if (SrcType->isMemberPointerType()) { 399 // Compare against -1. 400 llvm::Value *NegativeOne = llvm::Constant::getAllOnesValue(Src->getType()); 401 return Builder.CreateICmpNE(Src, NegativeOne, "tobool"); 402 } 403 404 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 405 "Unknown scalar type to convert"); 406 407 // Because of the type rules of C, we often end up computing a logical value, 408 // then zero extending it to int, then wanting it as a logical value again. 409 // Optimize this common case. 410 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) { 411 if (ZI->getOperand(0)->getType() == 412 llvm::Type::getInt1Ty(CGF.getLLVMContext())) { 413 Value *Result = ZI->getOperand(0); 414 // If there aren't any more uses, zap the instruction to save space. 415 // Note that there can be more uses, for example if this 416 // is the result of an assignment. 417 if (ZI->use_empty()) 418 ZI->eraseFromParent(); 419 return Result; 420 } 421 } 422 423 // Compare against an integer or pointer null. 424 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 425 return Builder.CreateICmpNE(Src, Zero, "tobool"); 426} 427 428/// EmitScalarConversion - Emit a conversion from the specified type to the 429/// specified destination type, both of which are LLVM scalar types. 430Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 431 QualType DstType) { 432 SrcType = CGF.getContext().getCanonicalType(SrcType); 433 DstType = CGF.getContext().getCanonicalType(DstType); 434 if (SrcType == DstType) return Src; 435 436 if (DstType->isVoidType()) return 0; 437 438 llvm::LLVMContext &VMContext = CGF.getLLVMContext(); 439 440 // Handle conversions to bool first, they are special: comparisons against 0. 441 if (DstType->isBooleanType()) 442 return EmitConversionToBool(Src, SrcType); 443 444 const llvm::Type *DstTy = ConvertType(DstType); 445 446 // Ignore conversions like int -> uint. 447 if (Src->getType() == DstTy) 448 return Src; 449 450 // Handle pointer conversions next: pointers can only be converted to/from 451 // other pointers and integers. Check for pointer types in terms of LLVM, as 452 // some native types (like Obj-C id) may map to a pointer type. 453 if (isa<llvm::PointerType>(DstTy)) { 454 // The source value may be an integer, or a pointer. 455 if (isa<llvm::PointerType>(Src->getType())) 456 return Builder.CreateBitCast(Src, DstTy, "conv"); 457 458 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 459 // First, convert to the correct width so that we control the kind of 460 // extension. 461 const llvm::Type *MiddleTy = 462 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 463 bool InputSigned = SrcType->isSignedIntegerType(); 464 llvm::Value* IntResult = 465 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 466 // Then, cast to pointer. 467 return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); 468 } 469 470 if (isa<llvm::PointerType>(Src->getType())) { 471 // Must be an ptr to int cast. 472 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 473 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 474 } 475 476 // A scalar can be splatted to an extended vector of the same element type 477 if (DstType->isExtVectorType() && !SrcType->isVectorType()) { 478 // Cast the scalar to element type 479 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType(); 480 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 481 482 // Insert the element in element zero of an undef vector 483 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 484 llvm::Value *Idx = 485 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0); 486 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 487 488 // Splat the element across to all elements 489 llvm::SmallVector<llvm::Constant*, 16> Args; 490 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 491 for (unsigned i = 0; i < NumElements; i++) 492 Args.push_back(llvm::ConstantInt::get( 493 llvm::Type::getInt32Ty(VMContext), 0)); 494 495 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 496 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 497 return Yay; 498 } 499 500 // Allow bitcast from vector to integer/fp of the same size. 501 if (isa<llvm::VectorType>(Src->getType()) || 502 isa<llvm::VectorType>(DstTy)) 503 return Builder.CreateBitCast(Src, DstTy, "conv"); 504 505 // Finally, we have the arithmetic types: real int/float. 506 if (isa<llvm::IntegerType>(Src->getType())) { 507 bool InputSigned = SrcType->isSignedIntegerType(); 508 if (isa<llvm::IntegerType>(DstTy)) 509 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 510 else if (InputSigned) 511 return Builder.CreateSIToFP(Src, DstTy, "conv"); 512 else 513 return Builder.CreateUIToFP(Src, DstTy, "conv"); 514 } 515 516 assert(Src->getType()->isFloatingPointTy() && "Unknown real conversion"); 517 if (isa<llvm::IntegerType>(DstTy)) { 518 if (DstType->isSignedIntegerType()) 519 return Builder.CreateFPToSI(Src, DstTy, "conv"); 520 else 521 return Builder.CreateFPToUI(Src, DstTy, "conv"); 522 } 523 524 assert(DstTy->isFloatingPointTy() && "Unknown real conversion"); 525 if (DstTy->getTypeID() < Src->getType()->getTypeID()) 526 return Builder.CreateFPTrunc(Src, DstTy, "conv"); 527 else 528 return Builder.CreateFPExt(Src, DstTy, "conv"); 529} 530 531/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 532/// type to the specified destination type, where the destination type is an 533/// LLVM scalar type. 534Value *ScalarExprEmitter:: 535EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 536 QualType SrcTy, QualType DstTy) { 537 // Get the source element type. 538 SrcTy = SrcTy->getAs<ComplexType>()->getElementType(); 539 540 // Handle conversions to bool first, they are special: comparisons against 0. 541 if (DstTy->isBooleanType()) { 542 // Complex != 0 -> (Real != 0) | (Imag != 0) 543 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 544 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 545 return Builder.CreateOr(Src.first, Src.second, "tobool"); 546 } 547 548 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 549 // the imaginary part of the complex value is discarded and the value of the 550 // real part is converted according to the conversion rules for the 551 // corresponding real type. 552 return EmitScalarConversion(Src.first, SrcTy, DstTy); 553} 554 555Value *ScalarExprEmitter::EmitNullValue(QualType Ty) { 556 const llvm::Type *LTy = ConvertType(Ty); 557 558 if (!Ty->isMemberPointerType()) 559 return llvm::Constant::getNullValue(LTy); 560 561 assert(!Ty->isMemberFunctionPointerType() && 562 "member function pointers are not scalar!"); 563 564 // Itanium C++ ABI 2.3: 565 // A NULL pointer is represented as -1. 566 return llvm::ConstantInt::get(LTy, -1ULL, /*isSigned=*/true); 567} 568 569//===----------------------------------------------------------------------===// 570// Visitor Methods 571//===----------------------------------------------------------------------===// 572 573Value *ScalarExprEmitter::VisitExpr(Expr *E) { 574 CGF.ErrorUnsupported(E, "scalar expression"); 575 if (E->getType()->isVoidType()) 576 return 0; 577 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 578} 579 580Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 581 llvm::SmallVector<llvm::Constant*, 32> indices; 582 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 583 indices.push_back(cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i)))); 584 } 585 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 586 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 587 Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); 588 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 589} 590Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { 591 Expr::EvalResult Result; 592 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 593 if (E->isArrow()) 594 CGF.EmitScalarExpr(E->getBase()); 595 else 596 EmitLValue(E->getBase()); 597 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 598 } 599 return EmitLoadOfLValue(E); 600} 601 602Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 603 TestAndClearIgnoreResultAssign(); 604 605 // Emit subscript expressions in rvalue context's. For most cases, this just 606 // loads the lvalue formed by the subscript expr. However, we have to be 607 // careful, because the base of a vector subscript is occasionally an rvalue, 608 // so we can't get it as an lvalue. 609 if (!E->getBase()->getType()->isVectorType()) 610 return EmitLoadOfLValue(E); 611 612 // Handle the vector case. The base must be a vector, the index must be an 613 // integer value. 614 Value *Base = Visit(E->getBase()); 615 Value *Idx = Visit(E->getIdx()); 616 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerType(); 617 Idx = Builder.CreateIntCast(Idx, 618 llvm::Type::getInt32Ty(CGF.getLLVMContext()), 619 IdxSigned, 620 "vecidxcast"); 621 return Builder.CreateExtractElement(Base, Idx, "vecext"); 622} 623 624static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, 625 unsigned Off, const llvm::Type *I32Ty) { 626 int MV = SVI->getMaskValue(Idx); 627 if (MV == -1) 628 return llvm::UndefValue::get(I32Ty); 629 return llvm::ConstantInt::get(I32Ty, Off+MV); 630} 631 632Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) { 633 bool Ignore = TestAndClearIgnoreResultAssign(); 634 (void)Ignore; 635 assert (Ignore == false && "init list ignored"); 636 unsigned NumInitElements = E->getNumInits(); 637 638 if (E->hadArrayRangeDesignator()) 639 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 640 641 const llvm::VectorType *VType = 642 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 643 644 // We have a scalar in braces. Just use the first element. 645 if (!VType) 646 return Visit(E->getInit(0)); 647 648 unsigned ResElts = VType->getNumElements(); 649 const llvm::Type *I32Ty = llvm::Type::getInt32Ty(CGF.getLLVMContext()); 650 651 // Loop over initializers collecting the Value for each, and remembering 652 // whether the source was swizzle (ExtVectorElementExpr). This will allow 653 // us to fold the shuffle for the swizzle into the shuffle for the vector 654 // initializer, since LLVM optimizers generally do not want to touch 655 // shuffles. 656 unsigned CurIdx = 0; 657 bool VIsUndefShuffle = false; 658 llvm::Value *V = llvm::UndefValue::get(VType); 659 for (unsigned i = 0; i != NumInitElements; ++i) { 660 Expr *IE = E->getInit(i); 661 Value *Init = Visit(IE); 662 llvm::SmallVector<llvm::Constant*, 16> Args; 663 664 const llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType()); 665 666 // Handle scalar elements. If the scalar initializer is actually one 667 // element of a different vector of the same width, use shuffle instead of 668 // extract+insert. 669 if (!VVT) { 670 if (isa<ExtVectorElementExpr>(IE)) { 671 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init); 672 673 if (EI->getVectorOperandType()->getNumElements() == ResElts) { 674 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand()); 675 Value *LHS = 0, *RHS = 0; 676 if (CurIdx == 0) { 677 // insert into undef -> shuffle (src, undef) 678 Args.push_back(C); 679 for (unsigned j = 1; j != ResElts; ++j) 680 Args.push_back(llvm::UndefValue::get(I32Ty)); 681 682 LHS = EI->getVectorOperand(); 683 RHS = V; 684 VIsUndefShuffle = true; 685 } else if (VIsUndefShuffle) { 686 // insert into undefshuffle && size match -> shuffle (v, src) 687 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V); 688 for (unsigned j = 0; j != CurIdx; ++j) 689 Args.push_back(getMaskElt(SVV, j, 0, I32Ty)); 690 Args.push_back(llvm::ConstantInt::get(I32Ty, 691 ResElts + C->getZExtValue())); 692 for (unsigned j = CurIdx + 1; j != ResElts; ++j) 693 Args.push_back(llvm::UndefValue::get(I32Ty)); 694 695 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 696 RHS = EI->getVectorOperand(); 697 VIsUndefShuffle = false; 698 } 699 if (!Args.empty()) { 700 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 701 V = Builder.CreateShuffleVector(LHS, RHS, Mask); 702 ++CurIdx; 703 continue; 704 } 705 } 706 } 707 Value *Idx = llvm::ConstantInt::get(I32Ty, CurIdx); 708 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 709 VIsUndefShuffle = false; 710 ++CurIdx; 711 continue; 712 } 713 714 unsigned InitElts = VVT->getNumElements(); 715 716 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's 717 // input is the same width as the vector being constructed, generate an 718 // optimized shuffle of the swizzle input into the result. 719 unsigned Offset = (CurIdx == 0) ? 0 : ResElts; 720 if (isa<ExtVectorElementExpr>(IE)) { 721 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init); 722 Value *SVOp = SVI->getOperand(0); 723 const llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType()); 724 725 if (OpTy->getNumElements() == ResElts) { 726 for (unsigned j = 0; j != CurIdx; ++j) { 727 // If the current vector initializer is a shuffle with undef, merge 728 // this shuffle directly into it. 729 if (VIsUndefShuffle) { 730 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0, 731 I32Ty)); 732 } else { 733 Args.push_back(llvm::ConstantInt::get(I32Ty, j)); 734 } 735 } 736 for (unsigned j = 0, je = InitElts; j != je; ++j) 737 Args.push_back(getMaskElt(SVI, j, Offset, I32Ty)); 738 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 739 Args.push_back(llvm::UndefValue::get(I32Ty)); 740 741 if (VIsUndefShuffle) 742 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 743 744 Init = SVOp; 745 } 746 } 747 748 // Extend init to result vector length, and then shuffle its contribution 749 // to the vector initializer into V. 750 if (Args.empty()) { 751 for (unsigned j = 0; j != InitElts; ++j) 752 Args.push_back(llvm::ConstantInt::get(I32Ty, j)); 753 for (unsigned j = InitElts; j != ResElts; ++j) 754 Args.push_back(llvm::UndefValue::get(I32Ty)); 755 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 756 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), 757 Mask, "vext"); 758 759 Args.clear(); 760 for (unsigned j = 0; j != CurIdx; ++j) 761 Args.push_back(llvm::ConstantInt::get(I32Ty, j)); 762 for (unsigned j = 0; j != InitElts; ++j) 763 Args.push_back(llvm::ConstantInt::get(I32Ty, j+Offset)); 764 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 765 Args.push_back(llvm::UndefValue::get(I32Ty)); 766 } 767 768 // If V is undef, make sure it ends up on the RHS of the shuffle to aid 769 // merging subsequent shuffles into this one. 770 if (CurIdx == 0) 771 std::swap(V, Init); 772 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 773 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); 774 VIsUndefShuffle = isa<llvm::UndefValue>(Init); 775 CurIdx += InitElts; 776 } 777 778 // FIXME: evaluate codegen vs. shuffling against constant null vector. 779 // Emit remaining default initializers. 780 const llvm::Type *EltTy = VType->getElementType(); 781 782 // Emit remaining default initializers 783 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { 784 Value *Idx = llvm::ConstantInt::get(I32Ty, CurIdx); 785 llvm::Value *Init = llvm::Constant::getNullValue(EltTy); 786 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 787 } 788 return V; 789} 790 791static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { 792 const Expr *E = CE->getSubExpr(); 793 794 if (CE->getCastKind() == CastExpr::CK_UncheckedDerivedToBase) 795 return false; 796 797 if (isa<CXXThisExpr>(E)) { 798 // We always assume that 'this' is never null. 799 return false; 800 } 801 802 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { 803 // And that lvalue casts are never null. 804 if (ICE->isLvalueCast()) 805 return false; 806 } 807 808 return true; 809} 810 811// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 812// have to handle a more broad range of conversions than explicit casts, as they 813// handle things like function to ptr-to-function decay etc. 814Value *ScalarExprEmitter::EmitCastExpr(CastExpr *CE) { 815 Expr *E = CE->getSubExpr(); 816 QualType DestTy = CE->getType(); 817 CastExpr::CastKind Kind = CE->getCastKind(); 818 819 if (!DestTy->isVoidType()) 820 TestAndClearIgnoreResultAssign(); 821 822 // Since almost all cast kinds apply to scalars, this switch doesn't have 823 // a default case, so the compiler will warn on a missing case. The cases 824 // are in the same order as in the CastKind enum. 825 switch (Kind) { 826 case CastExpr::CK_Unknown: 827 // FIXME: All casts should have a known kind! 828 //assert(0 && "Unknown cast kind!"); 829 break; 830 831 case CastExpr::CK_AnyPointerToObjCPointerCast: 832 case CastExpr::CK_AnyPointerToBlockPointerCast: 833 case CastExpr::CK_BitCast: { 834 Value *Src = Visit(const_cast<Expr*>(E)); 835 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 836 } 837 case CastExpr::CK_NoOp: 838 case CastExpr::CK_UserDefinedConversion: 839 return Visit(const_cast<Expr*>(E)); 840 841 case CastExpr::CK_BaseToDerived: { 842 const CXXRecordDecl *DerivedClassDecl = 843 DestTy->getCXXRecordDeclForPointerType(); 844 845 return CGF.GetAddressOfDerivedClass(Visit(E), DerivedClassDecl, 846 CE->getBasePath(), 847 ShouldNullCheckClassCastValue(CE)); 848 } 849 case CastExpr::CK_UncheckedDerivedToBase: 850 case CastExpr::CK_DerivedToBase: { 851 const RecordType *DerivedClassTy = 852 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 853 CXXRecordDecl *DerivedClassDecl = 854 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 855 856 return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl, 857 CE->getBasePath(), 858 ShouldNullCheckClassCastValue(CE)); 859 } 860 case CastExpr::CK_Dynamic: { 861 Value *V = Visit(const_cast<Expr*>(E)); 862 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 863 return CGF.EmitDynamicCast(V, DCE); 864 } 865 case CastExpr::CK_ToUnion: 866 assert(0 && "Should be unreachable!"); 867 break; 868 869 case CastExpr::CK_ArrayToPointerDecay: { 870 assert(E->getType()->isArrayType() && 871 "Array to pointer decay must have array source type!"); 872 873 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 874 875 // Note that VLA pointers are always decayed, so we don't need to do 876 // anything here. 877 if (!E->getType()->isVariableArrayType()) { 878 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 879 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 880 ->getElementType()) && 881 "Expected pointer to array"); 882 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 883 } 884 885 return V; 886 } 887 case CastExpr::CK_FunctionToPointerDecay: 888 return EmitLValue(E).getAddress(); 889 890 case CastExpr::CK_NullToMemberPointer: 891 return CGF.CGM.EmitNullConstant(DestTy); 892 893 case CastExpr::CK_BaseToDerivedMemberPointer: 894 case CastExpr::CK_DerivedToBaseMemberPointer: { 895 Value *Src = Visit(E); 896 897 // See if we need to adjust the pointer. 898 const CXXRecordDecl *BaseDecl = 899 cast<CXXRecordDecl>(E->getType()->getAs<MemberPointerType>()-> 900 getClass()->getAs<RecordType>()->getDecl()); 901 const CXXRecordDecl *DerivedDecl = 902 cast<CXXRecordDecl>(CE->getType()->getAs<MemberPointerType>()-> 903 getClass()->getAs<RecordType>()->getDecl()); 904 if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) 905 std::swap(DerivedDecl, BaseDecl); 906 907 if (llvm::Constant *Adj = 908 CGF.CGM.GetNonVirtualBaseClassOffset(DerivedDecl, 909 CE->getBasePath())) { 910 if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) 911 Src = Builder.CreateSub(Src, Adj, "adj"); 912 else 913 Src = Builder.CreateAdd(Src, Adj, "adj"); 914 } 915 return Src; 916 } 917 918 case CastExpr::CK_ConstructorConversion: 919 assert(0 && "Should be unreachable!"); 920 break; 921 922 case CastExpr::CK_IntegralToPointer: { 923 Value *Src = Visit(const_cast<Expr*>(E)); 924 925 // First, convert to the correct width so that we control the kind of 926 // extension. 927 const llvm::Type *MiddleTy = 928 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 929 bool InputSigned = E->getType()->isSignedIntegerType(); 930 llvm::Value* IntResult = 931 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 932 933 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 934 } 935 case CastExpr::CK_PointerToIntegral: { 936 Value *Src = Visit(const_cast<Expr*>(E)); 937 return Builder.CreatePtrToInt(Src, ConvertType(DestTy)); 938 } 939 case CastExpr::CK_ToVoid: { 940 CGF.EmitAnyExpr(E, 0, false, true); 941 return 0; 942 } 943 case CastExpr::CK_VectorSplat: { 944 const llvm::Type *DstTy = ConvertType(DestTy); 945 Value *Elt = Visit(const_cast<Expr*>(E)); 946 947 // Insert the element in element zero of an undef vector 948 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 949 llvm::Value *Idx = 950 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0); 951 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 952 953 // Splat the element across to all elements 954 llvm::SmallVector<llvm::Constant*, 16> Args; 955 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 956 for (unsigned i = 0; i < NumElements; i++) 957 Args.push_back(llvm::ConstantInt::get( 958 llvm::Type::getInt32Ty(VMContext), 0)); 959 960 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 961 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 962 return Yay; 963 } 964 case CastExpr::CK_IntegralCast: 965 case CastExpr::CK_IntegralToFloating: 966 case CastExpr::CK_FloatingToIntegral: 967 case CastExpr::CK_FloatingCast: 968 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 969 970 case CastExpr::CK_MemberPointerToBoolean: 971 return CGF.EvaluateExprAsBool(E); 972 } 973 974 // Handle cases where the source is an non-complex type. 975 976 if (!CGF.hasAggregateLLVMType(E->getType())) { 977 Value *Src = Visit(const_cast<Expr*>(E)); 978 979 // Use EmitScalarConversion to perform the conversion. 980 return EmitScalarConversion(Src, E->getType(), DestTy); 981 } 982 983 if (E->getType()->isAnyComplexType()) { 984 // Handle cases where the source is a complex type. 985 bool IgnoreImag = true; 986 bool IgnoreImagAssign = true; 987 bool IgnoreReal = IgnoreResultAssign; 988 bool IgnoreRealAssign = IgnoreResultAssign; 989 if (DestTy->isBooleanType()) 990 IgnoreImagAssign = IgnoreImag = false; 991 else if (DestTy->isVoidType()) { 992 IgnoreReal = IgnoreImag = false; 993 IgnoreRealAssign = IgnoreImagAssign = true; 994 } 995 CodeGenFunction::ComplexPairTy V 996 = CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign, 997 IgnoreImagAssign); 998 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 999 } 1000 1001 // Okay, this is a cast from an aggregate. It must be a cast to void. Just 1002 // evaluate the result and return. 1003 CGF.EmitAggExpr(E, 0, false, true); 1004 return 0; 1005} 1006 1007Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 1008 return CGF.EmitCompoundStmt(*E->getSubStmt(), 1009 !E->getType()->isVoidType()).getScalarVal(); 1010} 1011 1012Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 1013 llvm::Value *V = CGF.GetAddrOfBlockDecl(E); 1014 if (E->getType().isObjCGCWeak()) 1015 return CGF.CGM.getObjCRuntime().EmitObjCWeakRead(CGF, V); 1016 return Builder.CreateLoad(V, "tmp"); 1017} 1018 1019//===----------------------------------------------------------------------===// 1020// Unary Operators 1021//===----------------------------------------------------------------------===// 1022 1023Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1024 TestAndClearIgnoreResultAssign(); 1025 Value *Op = Visit(E->getSubExpr()); 1026 if (Op->getType()->isFPOrFPVectorTy()) 1027 return Builder.CreateFNeg(Op, "neg"); 1028 return Builder.CreateNeg(Op, "neg"); 1029} 1030 1031Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1032 TestAndClearIgnoreResultAssign(); 1033 Value *Op = Visit(E->getSubExpr()); 1034 return Builder.CreateNot(Op, "neg"); 1035} 1036 1037Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1038 // Compare operand to zero. 1039 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1040 1041 // Invert value. 1042 // TODO: Could dynamically modify easy computations here. For example, if 1043 // the operand is an icmp ne, turn into icmp eq. 1044 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1045 1046 // ZExt result to the expr type. 1047 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1048} 1049 1050Value *ScalarExprEmitter::VisitOffsetOfExpr(const OffsetOfExpr *E) { 1051 Expr::EvalResult Result; 1052 if(E->Evaluate(Result, CGF.getContext())) 1053 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 1054 1055 // FIXME: Cannot support code generation for non-constant offsetof. 1056 unsigned DiagID = CGF.CGM.getDiags().getCustomDiagID(Diagnostic::Error, 1057 "cannot compile non-constant __builtin_offsetof"); 1058 CGF.CGM.getDiags().Report(CGF.getContext().getFullLoc(E->getLocStart()), 1059 DiagID) 1060 << E->getSourceRange(); 1061 1062 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1063} 1064 1065/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of 1066/// argument of the sizeof expression as an integer. 1067Value * 1068ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { 1069 QualType TypeToSize = E->getTypeOfArgument(); 1070 if (E->isSizeOf()) { 1071 if (const VariableArrayType *VAT = 1072 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1073 if (E->isArgumentType()) { 1074 // sizeof(type) - make sure to emit the VLA size. 1075 CGF.EmitVLASize(TypeToSize); 1076 } else { 1077 // C99 6.5.3.4p2: If the argument is an expression of type 1078 // VLA, it is evaluated. 1079 CGF.EmitAnyExpr(E->getArgumentExpr()); 1080 } 1081 1082 return CGF.GetVLASize(VAT); 1083 } 1084 } 1085 1086 // If this isn't sizeof(vla), the result must be constant; use the constant 1087 // folding logic so we don't have to duplicate it here. 1088 Expr::EvalResult Result; 1089 E->Evaluate(Result, CGF.getContext()); 1090 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 1091} 1092 1093Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1094 Expr *Op = E->getSubExpr(); 1095 if (Op->getType()->isAnyComplexType()) 1096 return CGF.EmitComplexExpr(Op, false, true, false, true).first; 1097 return Visit(Op); 1098} 1099Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1100 Expr *Op = E->getSubExpr(); 1101 if (Op->getType()->isAnyComplexType()) 1102 return CGF.EmitComplexExpr(Op, true, false, true, false).second; 1103 1104 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1105 // effects are evaluated, but not the actual value. 1106 if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) 1107 CGF.EmitLValue(Op); 1108 else 1109 CGF.EmitScalarExpr(Op, true); 1110 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1111} 1112 1113Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) { 1114 Value* ResultAsPtr = EmitLValue(E->getSubExpr()).getAddress(); 1115 const llvm::Type* ResultType = ConvertType(E->getType()); 1116 return Builder.CreatePtrToInt(ResultAsPtr, ResultType, "offsetof"); 1117} 1118 1119//===----------------------------------------------------------------------===// 1120// Binary Operators 1121//===----------------------------------------------------------------------===// 1122 1123BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1124 TestAndClearIgnoreResultAssign(); 1125 BinOpInfo Result; 1126 Result.LHS = Visit(E->getLHS()); 1127 Result.RHS = Visit(E->getRHS()); 1128 Result.Ty = E->getType(); 1129 Result.E = E; 1130 return Result; 1131} 1132 1133LValue ScalarExprEmitter::EmitCompoundAssignLValue( 1134 const CompoundAssignOperator *E, 1135 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &), 1136 Value *&BitFieldResult) { 1137 QualType LHSTy = E->getLHS()->getType(); 1138 BitFieldResult = 0; 1139 BinOpInfo OpInfo; 1140 1141 if (E->getComputationResultType()->isAnyComplexType()) { 1142 // This needs to go through the complex expression emitter, but it's a tad 1143 // complicated to do that... I'm leaving it out for now. (Note that we do 1144 // actually need the imaginary part of the RHS for multiplication and 1145 // division.) 1146 CGF.ErrorUnsupported(E, "complex compound assignment"); 1147 llvm::UndefValue::get(CGF.ConvertType(E->getType())); 1148 return LValue(); 1149 } 1150 1151 // Emit the RHS first. __block variables need to have the rhs evaluated 1152 // first, plus this should improve codegen a little. 1153 OpInfo.RHS = Visit(E->getRHS()); 1154 OpInfo.Ty = E->getComputationResultType(); 1155 OpInfo.E = E; 1156 // Load/convert the LHS. 1157 LValue LHSLV = EmitCheckedLValue(E->getLHS()); 1158 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 1159 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 1160 E->getComputationLHSType()); 1161 1162 // Expand the binary operator. 1163 Value *Result = (this->*Func)(OpInfo); 1164 1165 // Convert the result back to the LHS type. 1166 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 1167 1168 // Store the result value into the LHS lvalue. Bit-fields are handled 1169 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 1170 // 'An assignment expression has the value of the left operand after the 1171 // assignment...'. 1172 if (LHSLV.isBitField()) { 1173 if (!LHSLV.isVolatileQualified()) { 1174 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, 1175 &Result); 1176 BitFieldResult = Result; 1177 return LHSLV; 1178 } else 1179 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy); 1180 } else 1181 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); 1182 return LHSLV; 1183} 1184 1185Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 1186 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 1187 bool Ignore = TestAndClearIgnoreResultAssign(); 1188 Value *BitFieldResult; 1189 LValue LHSLV = EmitCompoundAssignLValue(E, Func, BitFieldResult); 1190 if (BitFieldResult) 1191 return BitFieldResult; 1192 1193 if (Ignore) 1194 return 0; 1195 return EmitLoadOfLValue(LHSLV, E->getType()); 1196} 1197 1198 1199Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 1200 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1201 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 1202 else if (Ops.Ty->isUnsignedIntegerType()) 1203 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 1204 else 1205 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 1206} 1207 1208Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 1209 // Rem in C can't be a floating point type: C99 6.5.5p2. 1210 if (Ops.Ty->isUnsignedIntegerType()) 1211 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 1212 else 1213 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 1214} 1215 1216Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 1217 unsigned IID; 1218 unsigned OpID = 0; 1219 1220 switch (Ops.E->getOpcode()) { 1221 case BinaryOperator::Add: 1222 case BinaryOperator::AddAssign: 1223 OpID = 1; 1224 IID = llvm::Intrinsic::sadd_with_overflow; 1225 break; 1226 case BinaryOperator::Sub: 1227 case BinaryOperator::SubAssign: 1228 OpID = 2; 1229 IID = llvm::Intrinsic::ssub_with_overflow; 1230 break; 1231 case BinaryOperator::Mul: 1232 case BinaryOperator::MulAssign: 1233 OpID = 3; 1234 IID = llvm::Intrinsic::smul_with_overflow; 1235 break; 1236 default: 1237 assert(false && "Unsupported operation for overflow detection"); 1238 IID = 0; 1239 } 1240 OpID <<= 1; 1241 OpID |= 1; 1242 1243 const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1244 1245 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1); 1246 1247 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1248 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1249 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1250 1251 // Branch in case of overflow. 1252 llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); 1253 llvm::BasicBlock *overflowBB = 1254 CGF.createBasicBlock("overflow", CGF.CurFn); 1255 llvm::BasicBlock *continueBB = 1256 CGF.createBasicBlock("overflow.continue", CGF.CurFn); 1257 1258 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1259 1260 // Handle overflow 1261 1262 Builder.SetInsertPoint(overflowBB); 1263 1264 // Handler is: 1265 // long long *__overflow_handler)(long long a, long long b, char op, 1266 // char width) 1267 std::vector<const llvm::Type*> handerArgTypes; 1268 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1269 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1270 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1271 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1272 llvm::FunctionType *handlerTy = llvm::FunctionType::get( 1273 llvm::Type::getInt64Ty(VMContext), handerArgTypes, false); 1274 llvm::Value *handlerFunction = 1275 CGF.CGM.getModule().getOrInsertGlobal("__overflow_handler", 1276 llvm::PointerType::getUnqual(handlerTy)); 1277 handlerFunction = Builder.CreateLoad(handlerFunction); 1278 1279 llvm::Value *handlerResult = Builder.CreateCall4(handlerFunction, 1280 Builder.CreateSExt(Ops.LHS, llvm::Type::getInt64Ty(VMContext)), 1281 Builder.CreateSExt(Ops.RHS, llvm::Type::getInt64Ty(VMContext)), 1282 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), OpID), 1283 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), 1284 cast<llvm::IntegerType>(opTy)->getBitWidth())); 1285 1286 handlerResult = Builder.CreateTrunc(handlerResult, opTy); 1287 1288 Builder.CreateBr(continueBB); 1289 1290 // Set up the continuation 1291 Builder.SetInsertPoint(continueBB); 1292 // Get the correct result 1293 llvm::PHINode *phi = Builder.CreatePHI(opTy); 1294 phi->reserveOperandSpace(2); 1295 phi->addIncoming(result, initialBB); 1296 phi->addIncoming(handlerResult, overflowBB); 1297 1298 return phi; 1299} 1300 1301Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 1302 if (!Ops.Ty->isAnyPointerType()) { 1303 if (CGF.getContext().getLangOptions().OverflowChecking && 1304 Ops.Ty->isSignedIntegerType()) 1305 return EmitOverflowCheckedBinOp(Ops); 1306 1307 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1308 return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add"); 1309 1310 // Signed integer overflow is undefined behavior. 1311 if (Ops.Ty->isSignedIntegerType()) 1312 return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add"); 1313 1314 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1315 } 1316 1317 if (Ops.Ty->isPointerType() && 1318 Ops.Ty->getAs<PointerType>()->isVariableArrayType()) { 1319 // The amount of the addition needs to account for the VLA size 1320 CGF.ErrorUnsupported(Ops.E, "VLA pointer addition"); 1321 } 1322 Value *Ptr, *Idx; 1323 Expr *IdxExp; 1324 const PointerType *PT = Ops.E->getLHS()->getType()->getAs<PointerType>(); 1325 const ObjCObjectPointerType *OPT = 1326 Ops.E->getLHS()->getType()->getAs<ObjCObjectPointerType>(); 1327 if (PT || OPT) { 1328 Ptr = Ops.LHS; 1329 Idx = Ops.RHS; 1330 IdxExp = Ops.E->getRHS(); 1331 } else { // int + pointer 1332 PT = Ops.E->getRHS()->getType()->getAs<PointerType>(); 1333 OPT = Ops.E->getRHS()->getType()->getAs<ObjCObjectPointerType>(); 1334 assert((PT || OPT) && "Invalid add expr"); 1335 Ptr = Ops.RHS; 1336 Idx = Ops.LHS; 1337 IdxExp = Ops.E->getLHS(); 1338 } 1339 1340 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1341 if (Width < CGF.LLVMPointerWidth) { 1342 // Zero or sign extend the pointer value based on whether the index is 1343 // signed or not. 1344 const llvm::Type *IdxType = 1345 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1346 if (IdxExp->getType()->isSignedIntegerType()) 1347 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1348 else 1349 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1350 } 1351 const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType(); 1352 // Handle interface types, which are not represented with a concrete type. 1353 if (const ObjCObjectType *OIT = ElementType->getAs<ObjCObjectType>()) { 1354 llvm::Value *InterfaceSize = 1355 llvm::ConstantInt::get(Idx->getType(), 1356 CGF.getContext().getTypeSizeInChars(OIT).getQuantity()); 1357 Idx = Builder.CreateMul(Idx, InterfaceSize); 1358 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1359 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1360 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1361 return Builder.CreateBitCast(Res, Ptr->getType()); 1362 } 1363 1364 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 1365 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 1366 // future proof. 1367 if (ElementType->isVoidType() || ElementType->isFunctionType()) { 1368 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1369 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1370 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1371 return Builder.CreateBitCast(Res, Ptr->getType()); 1372 } 1373 1374 return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr"); 1375} 1376 1377Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 1378 if (!isa<llvm::PointerType>(Ops.LHS->getType())) { 1379 if (CGF.getContext().getLangOptions().OverflowChecking 1380 && Ops.Ty->isSignedIntegerType()) 1381 return EmitOverflowCheckedBinOp(Ops); 1382 1383 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1384 return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub"); 1385 1386 // Signed integer overflow is undefined behavior. 1387 if (Ops.Ty->isSignedIntegerType()) 1388 return Builder.CreateNSWSub(Ops.LHS, Ops.RHS, "sub"); 1389 1390 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1391 } 1392 1393 if (Ops.E->getLHS()->getType()->isPointerType() && 1394 Ops.E->getLHS()->getType()->getAs<PointerType>()->isVariableArrayType()) { 1395 // The amount of the addition needs to account for the VLA size for 1396 // ptr-int 1397 // The amount of the division needs to account for the VLA size for 1398 // ptr-ptr. 1399 CGF.ErrorUnsupported(Ops.E, "VLA pointer subtraction"); 1400 } 1401 1402 const QualType LHSType = Ops.E->getLHS()->getType(); 1403 const QualType LHSElementType = LHSType->getPointeeType(); 1404 if (!isa<llvm::PointerType>(Ops.RHS->getType())) { 1405 // pointer - int 1406 Value *Idx = Ops.RHS; 1407 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1408 if (Width < CGF.LLVMPointerWidth) { 1409 // Zero or sign extend the pointer value based on whether the index is 1410 // signed or not. 1411 const llvm::Type *IdxType = 1412 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1413 if (Ops.E->getRHS()->getType()->isSignedIntegerType()) 1414 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1415 else 1416 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1417 } 1418 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); 1419 1420 // Handle interface types, which are not represented with a concrete type. 1421 if (const ObjCObjectType *OIT = LHSElementType->getAs<ObjCObjectType>()) { 1422 llvm::Value *InterfaceSize = 1423 llvm::ConstantInt::get(Idx->getType(), 1424 CGF.getContext(). 1425 getTypeSizeInChars(OIT).getQuantity()); 1426 Idx = Builder.CreateMul(Idx, InterfaceSize); 1427 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1428 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1429 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr"); 1430 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1431 } 1432 1433 // Explicitly handle GNU void* and function pointer arithmetic 1434 // extensions. The GNU void* casts amount to no-ops since our void* type is 1435 // i8*, but this is future proof. 1436 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1437 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1438 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1439 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); 1440 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1441 } 1442 1443 return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr"); 1444 } else { 1445 // pointer - pointer 1446 Value *LHS = Ops.LHS; 1447 Value *RHS = Ops.RHS; 1448 1449 CharUnits ElementSize; 1450 1451 // Handle GCC extension for pointer arithmetic on void* and function pointer 1452 // types. 1453 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1454 ElementSize = CharUnits::One(); 1455 } else { 1456 ElementSize = CGF.getContext().getTypeSizeInChars(LHSElementType); 1457 } 1458 1459 const llvm::Type *ResultType = ConvertType(Ops.Ty); 1460 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 1461 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 1462 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 1463 1464 // Optimize out the shift for element size of 1. 1465 if (ElementSize.isOne()) 1466 return BytesBetween; 1467 1468 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 1469 // pointer difference in C is only defined in the case where both operands 1470 // are pointing to elements of an array. 1471 Value *BytesPerElt = 1472 llvm::ConstantInt::get(ResultType, ElementSize.getQuantity()); 1473 return Builder.CreateExactSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 1474 } 1475} 1476 1477Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 1478 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1479 // RHS to the same size as the LHS. 1480 Value *RHS = Ops.RHS; 1481 if (Ops.LHS->getType() != RHS->getType()) 1482 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1483 1484 if (CGF.CatchUndefined 1485 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1486 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1487 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1488 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1489 llvm::ConstantInt::get(RHS->getType(), Width)), 1490 Cont, CGF.getTrapBB()); 1491 CGF.EmitBlock(Cont); 1492 } 1493 1494 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 1495} 1496 1497Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 1498 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1499 // RHS to the same size as the LHS. 1500 Value *RHS = Ops.RHS; 1501 if (Ops.LHS->getType() != RHS->getType()) 1502 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1503 1504 if (CGF.CatchUndefined 1505 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1506 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1507 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1508 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1509 llvm::ConstantInt::get(RHS->getType(), Width)), 1510 Cont, CGF.getTrapBB()); 1511 CGF.EmitBlock(Cont); 1512 } 1513 1514 if (Ops.Ty->isUnsignedIntegerType()) 1515 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 1516 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 1517} 1518 1519Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 1520 unsigned SICmpOpc, unsigned FCmpOpc) { 1521 TestAndClearIgnoreResultAssign(); 1522 Value *Result; 1523 QualType LHSTy = E->getLHS()->getType(); 1524 if (LHSTy->isMemberFunctionPointerType()) { 1525 Value *LHSPtr = CGF.EmitAnyExprToTemp(E->getLHS()).getAggregateAddr(); 1526 Value *RHSPtr = CGF.EmitAnyExprToTemp(E->getRHS()).getAggregateAddr(); 1527 llvm::Value *LHSFunc = Builder.CreateStructGEP(LHSPtr, 0); 1528 LHSFunc = Builder.CreateLoad(LHSFunc); 1529 llvm::Value *RHSFunc = Builder.CreateStructGEP(RHSPtr, 0); 1530 RHSFunc = Builder.CreateLoad(RHSFunc); 1531 Value *ResultF = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1532 LHSFunc, RHSFunc, "cmp.func"); 1533 Value *NullPtr = llvm::Constant::getNullValue(LHSFunc->getType()); 1534 Value *ResultNull = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1535 LHSFunc, NullPtr, "cmp.null"); 1536 llvm::Value *LHSAdj = Builder.CreateStructGEP(LHSPtr, 1); 1537 LHSAdj = Builder.CreateLoad(LHSAdj); 1538 llvm::Value *RHSAdj = Builder.CreateStructGEP(RHSPtr, 1); 1539 RHSAdj = Builder.CreateLoad(RHSAdj); 1540 Value *ResultA = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1541 LHSAdj, RHSAdj, "cmp.adj"); 1542 if (E->getOpcode() == BinaryOperator::EQ) { 1543 Result = Builder.CreateOr(ResultNull, ResultA, "or.na"); 1544 Result = Builder.CreateAnd(Result, ResultF, "and.f"); 1545 } else { 1546 assert(E->getOpcode() == BinaryOperator::NE && 1547 "Member pointer comparison other than == or != ?"); 1548 Result = Builder.CreateAnd(ResultNull, ResultA, "and.na"); 1549 Result = Builder.CreateOr(Result, ResultF, "or.f"); 1550 } 1551 } else if (!LHSTy->isAnyComplexType()) { 1552 Value *LHS = Visit(E->getLHS()); 1553 Value *RHS = Visit(E->getRHS()); 1554 1555 if (LHS->getType()->isFPOrFPVectorTy()) { 1556 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 1557 LHS, RHS, "cmp"); 1558 } else if (LHSTy->isSignedIntegerType()) { 1559 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 1560 LHS, RHS, "cmp"); 1561 } else { 1562 // Unsigned integers and pointers. 1563 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1564 LHS, RHS, "cmp"); 1565 } 1566 1567 // If this is a vector comparison, sign extend the result to the appropriate 1568 // vector integer type and return it (don't convert to bool). 1569 if (LHSTy->isVectorType()) 1570 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 1571 1572 } else { 1573 // Complex Comparison: can only be an equality comparison. 1574 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 1575 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 1576 1577 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 1578 1579 Value *ResultR, *ResultI; 1580 if (CETy->isRealFloatingType()) { 1581 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1582 LHS.first, RHS.first, "cmp.r"); 1583 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1584 LHS.second, RHS.second, "cmp.i"); 1585 } else { 1586 // Complex comparisons can only be equality comparisons. As such, signed 1587 // and unsigned opcodes are the same. 1588 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1589 LHS.first, RHS.first, "cmp.r"); 1590 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1591 LHS.second, RHS.second, "cmp.i"); 1592 } 1593 1594 if (E->getOpcode() == BinaryOperator::EQ) { 1595 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 1596 } else { 1597 assert(E->getOpcode() == BinaryOperator::NE && 1598 "Complex comparison other than == or != ?"); 1599 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 1600 } 1601 } 1602 1603 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 1604} 1605 1606Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 1607 bool Ignore = TestAndClearIgnoreResultAssign(); 1608 1609 // __block variables need to have the rhs evaluated first, plus this should 1610 // improve codegen just a little. 1611 Value *RHS = Visit(E->getRHS()); 1612 LValue LHS = EmitCheckedLValue(E->getLHS()); 1613 1614 // Store the value into the LHS. Bit-fields are handled specially 1615 // because the result is altered by the store, i.e., [C99 6.5.16p1] 1616 // 'An assignment expression has the value of the left operand after 1617 // the assignment...'. 1618 if (LHS.isBitField()) { 1619 if (!LHS.isVolatileQualified()) { 1620 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), 1621 &RHS); 1622 return RHS; 1623 } else 1624 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType()); 1625 } else 1626 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 1627 if (Ignore) 1628 return 0; 1629 return EmitLoadOfLValue(LHS, E->getType()); 1630} 1631 1632Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 1633 const llvm::Type *ResTy = ConvertType(E->getType()); 1634 1635 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 1636 // If we have 1 && X, just emit X without inserting the control flow. 1637 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1638 if (Cond == 1) { // If we have 1 && X, just emit X. 1639 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1640 // ZExt result to int or bool. 1641 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 1642 } 1643 1644 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 1645 if (!CGF.ContainsLabel(E->getRHS())) 1646 return llvm::Constant::getNullValue(ResTy); 1647 } 1648 1649 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 1650 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 1651 1652 // Branch on the LHS first. If it is false, go to the failure (cont) block. 1653 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 1654 1655 // Any edges into the ContBlock are now from an (indeterminate number of) 1656 // edges from this first condition. All of these values will be false. Start 1657 // setting up the PHI node in the Cont Block for this. 1658 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1659 "", ContBlock); 1660 PN->reserveOperandSpace(2); // Normal case, two inputs. 1661 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1662 PI != PE; ++PI) 1663 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 1664 1665 CGF.BeginConditionalBranch(); 1666 CGF.EmitBlock(RHSBlock); 1667 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1668 CGF.EndConditionalBranch(); 1669 1670 // Reaquire the RHS block, as there may be subblocks inserted. 1671 RHSBlock = Builder.GetInsertBlock(); 1672 1673 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1674 // into the phi node for the edge with the value of RHSCond. 1675 CGF.EmitBlock(ContBlock); 1676 PN->addIncoming(RHSCond, RHSBlock); 1677 1678 // ZExt result to int. 1679 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); 1680} 1681 1682Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 1683 const llvm::Type *ResTy = ConvertType(E->getType()); 1684 1685 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 1686 // If we have 0 || X, just emit X without inserting the control flow. 1687 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1688 if (Cond == -1) { // If we have 0 || X, just emit X. 1689 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1690 // ZExt result to int or bool. 1691 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 1692 } 1693 1694 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 1695 if (!CGF.ContainsLabel(E->getRHS())) 1696 return llvm::ConstantInt::get(ResTy, 1); 1697 } 1698 1699 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 1700 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 1701 1702 // Branch on the LHS first. If it is true, go to the success (cont) block. 1703 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 1704 1705 // Any edges into the ContBlock are now from an (indeterminate number of) 1706 // edges from this first condition. All of these values will be true. Start 1707 // setting up the PHI node in the Cont Block for this. 1708 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1709 "", ContBlock); 1710 PN->reserveOperandSpace(2); // Normal case, two inputs. 1711 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1712 PI != PE; ++PI) 1713 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 1714 1715 CGF.BeginConditionalBranch(); 1716 1717 // Emit the RHS condition as a bool value. 1718 CGF.EmitBlock(RHSBlock); 1719 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1720 1721 CGF.EndConditionalBranch(); 1722 1723 // Reaquire the RHS block, as there may be subblocks inserted. 1724 RHSBlock = Builder.GetInsertBlock(); 1725 1726 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1727 // into the phi node for the edge with the value of RHSCond. 1728 CGF.EmitBlock(ContBlock); 1729 PN->addIncoming(RHSCond, RHSBlock); 1730 1731 // ZExt result to int. 1732 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 1733} 1734 1735Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 1736 CGF.EmitStmt(E->getLHS()); 1737 CGF.EnsureInsertPoint(); 1738 return Visit(E->getRHS()); 1739} 1740 1741//===----------------------------------------------------------------------===// 1742// Other Operators 1743//===----------------------------------------------------------------------===// 1744 1745/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 1746/// expression is cheap enough and side-effect-free enough to evaluate 1747/// unconditionally instead of conditionally. This is used to convert control 1748/// flow into selects in some cases. 1749static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 1750 CodeGenFunction &CGF) { 1751 if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) 1752 return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr(), CGF); 1753 1754 // TODO: Allow anything we can constant fold to an integer or fp constant. 1755 if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || 1756 isa<FloatingLiteral>(E)) 1757 return true; 1758 1759 // Non-volatile automatic variables too, to get "cond ? X : Y" where 1760 // X and Y are local variables. 1761 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 1762 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 1763 if (VD->hasLocalStorage() && !(CGF.getContext() 1764 .getCanonicalType(VD->getType()) 1765 .isVolatileQualified())) 1766 return true; 1767 1768 return false; 1769} 1770 1771 1772Value *ScalarExprEmitter:: 1773VisitConditionalOperator(const ConditionalOperator *E) { 1774 TestAndClearIgnoreResultAssign(); 1775 // If the condition constant folds and can be elided, try to avoid emitting 1776 // the condition and the dead arm. 1777 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ 1778 Expr *Live = E->getLHS(), *Dead = E->getRHS(); 1779 if (Cond == -1) 1780 std::swap(Live, Dead); 1781 1782 // If the dead side doesn't have labels we need, and if the Live side isn't 1783 // the gnu missing ?: extension (which we could handle, but don't bother 1784 // to), just emit the Live part. 1785 if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part 1786 Live) // Live part isn't missing. 1787 return Visit(Live); 1788 } 1789 1790 1791 // If this is a really simple expression (like x ? 4 : 5), emit this as a 1792 // select instead of as control flow. We can only do this if it is cheap and 1793 // safe to evaluate the LHS and RHS unconditionally. 1794 if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS(), 1795 CGF) && 1796 isCheapEnoughToEvaluateUnconditionally(E->getRHS(), CGF)) { 1797 llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); 1798 llvm::Value *LHS = Visit(E->getLHS()); 1799 llvm::Value *RHS = Visit(E->getRHS()); 1800 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 1801 } 1802 1803 1804 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 1805 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 1806 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 1807 Value *CondVal = 0; 1808 1809 // If we don't have the GNU missing condition extension, emit a branch on bool 1810 // the normal way. 1811 if (E->getLHS()) { 1812 // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for 1813 // the branch on bool. 1814 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); 1815 } else { 1816 // Otherwise, for the ?: extension, evaluate the conditional and then 1817 // convert it to bool the hard way. We do this explicitly because we need 1818 // the unconverted value for the missing middle value of the ?:. 1819 CondVal = CGF.EmitScalarExpr(E->getCond()); 1820 1821 // In some cases, EmitScalarConversion will delete the "CondVal" expression 1822 // if there are no extra uses (an optimization). Inhibit this by making an 1823 // extra dead use, because we're going to add a use of CondVal later. We 1824 // don't use the builder for this, because we don't want it to get optimized 1825 // away. This leaves dead code, but the ?: extension isn't common. 1826 new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", 1827 Builder.GetInsertBlock()); 1828 1829 Value *CondBoolVal = 1830 CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 1831 CGF.getContext().BoolTy); 1832 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 1833 } 1834 1835 CGF.BeginConditionalBranch(); 1836 CGF.EmitBlock(LHSBlock); 1837 1838 // Handle the GNU extension for missing LHS. 1839 Value *LHS; 1840 if (E->getLHS()) 1841 LHS = Visit(E->getLHS()); 1842 else // Perform promotions, to handle cases like "short ?: int" 1843 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); 1844 1845 CGF.EndConditionalBranch(); 1846 LHSBlock = Builder.GetInsertBlock(); 1847 CGF.EmitBranch(ContBlock); 1848 1849 CGF.BeginConditionalBranch(); 1850 CGF.EmitBlock(RHSBlock); 1851 1852 Value *RHS = Visit(E->getRHS()); 1853 CGF.EndConditionalBranch(); 1854 RHSBlock = Builder.GetInsertBlock(); 1855 CGF.EmitBranch(ContBlock); 1856 1857 CGF.EmitBlock(ContBlock); 1858 1859 // If the LHS or RHS is a throw expression, it will be legitimately null. 1860 if (!LHS) 1861 return RHS; 1862 if (!RHS) 1863 return LHS; 1864 1865 // Create a PHI node for the real part. 1866 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 1867 PN->reserveOperandSpace(2); 1868 PN->addIncoming(LHS, LHSBlock); 1869 PN->addIncoming(RHS, RHSBlock); 1870 return PN; 1871} 1872 1873Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 1874 return Visit(E->getChosenSubExpr(CGF.getContext())); 1875} 1876 1877Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 1878 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 1879 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 1880 1881 // If EmitVAArg fails, we fall back to the LLVM instruction. 1882 if (!ArgPtr) 1883 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 1884 1885 // FIXME Volatility. 1886 return Builder.CreateLoad(ArgPtr); 1887} 1888 1889Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { 1890 return CGF.BuildBlockLiteralTmp(BE); 1891} 1892 1893//===----------------------------------------------------------------------===// 1894// Entry Point into this File 1895//===----------------------------------------------------------------------===// 1896 1897/// EmitScalarExpr - Emit the computation of the specified expression of scalar 1898/// type, ignoring the result. 1899Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 1900 assert(E && !hasAggregateLLVMType(E->getType()) && 1901 "Invalid scalar expression to emit"); 1902 1903 return ScalarExprEmitter(*this, IgnoreResultAssign) 1904 .Visit(const_cast<Expr*>(E)); 1905} 1906 1907/// EmitScalarConversion - Emit a conversion from the specified type to the 1908/// specified destination type, both of which are LLVM scalar types. 1909Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 1910 QualType DstTy) { 1911 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 1912 "Invalid scalar expression to emit"); 1913 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 1914} 1915 1916/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 1917/// type to the specified destination type, where the destination type is an 1918/// LLVM scalar type. 1919Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 1920 QualType SrcTy, 1921 QualType DstTy) { 1922 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 1923 "Invalid complex -> scalar conversion"); 1924 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 1925 DstTy); 1926} 1927 1928LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) { 1929 llvm::Value *V; 1930 // object->isa or (*object).isa 1931 // Generate code as for: *(Class*)object 1932 // build Class* type 1933 const llvm::Type *ClassPtrTy = ConvertType(E->getType()); 1934 1935 Expr *BaseExpr = E->getBase(); 1936 if (BaseExpr->isLvalue(getContext()) != Expr::LV_Valid) { 1937 V = CreateTempAlloca(ClassPtrTy, "resval"); 1938 llvm::Value *Src = EmitScalarExpr(BaseExpr); 1939 Builder.CreateStore(Src, V); 1940 LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType())); 1941 V = ScalarExprEmitter(*this).EmitLoadOfLValue(LV, E->getType()); 1942 } 1943 else { 1944 if (E->isArrow()) 1945 V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr); 1946 else 1947 V = EmitLValue(BaseExpr).getAddress(); 1948 } 1949 1950 // build Class* type 1951 ClassPtrTy = ClassPtrTy->getPointerTo(); 1952 V = Builder.CreateBitCast(V, ClassPtrTy); 1953 LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType())); 1954 return LV; 1955} 1956 1957 1958LValue CodeGenFunction::EmitCompoundAssignOperatorLValue( 1959 const CompoundAssignOperator *E) { 1960 ScalarExprEmitter Scalar(*this); 1961 Value *BitFieldResult = 0; 1962 switch (E->getOpcode()) { 1963#define COMPOUND_OP(Op) \ 1964 case BinaryOperator::Op##Assign: \ 1965 return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \ 1966 BitFieldResult) 1967 COMPOUND_OP(Mul); 1968 COMPOUND_OP(Div); 1969 COMPOUND_OP(Rem); 1970 COMPOUND_OP(Add); 1971 COMPOUND_OP(Sub); 1972 COMPOUND_OP(Shl); 1973 COMPOUND_OP(Shr); 1974 COMPOUND_OP(And); 1975 COMPOUND_OP(Xor); 1976 COMPOUND_OP(Or); 1977#undef COMPOUND_OP 1978 1979 case BinaryOperator::PtrMemD: 1980 case BinaryOperator::PtrMemI: 1981 case BinaryOperator::Mul: 1982 case BinaryOperator::Div: 1983 case BinaryOperator::Rem: 1984 case BinaryOperator::Add: 1985 case BinaryOperator::Sub: 1986 case BinaryOperator::Shl: 1987 case BinaryOperator::Shr: 1988 case BinaryOperator::LT: 1989 case BinaryOperator::GT: 1990 case BinaryOperator::LE: 1991 case BinaryOperator::GE: 1992 case BinaryOperator::EQ: 1993 case BinaryOperator::NE: 1994 case BinaryOperator::And: 1995 case BinaryOperator::Xor: 1996 case BinaryOperator::Or: 1997 case BinaryOperator::LAnd: 1998 case BinaryOperator::LOr: 1999 case BinaryOperator::Assign: 2000 case BinaryOperator::Comma: 2001 assert(false && "Not valid compound assignment operators"); 2002 break; 2003 } 2004 2005 llvm_unreachable("Unhandled compound assignment operator"); 2006} 2007