CGExprScalar.cpp revision 9f9efe6d58f49bce01b548bf81245f053b632a02
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 //===--------------------------------------------------------------------===// 100 // Visitor Methods 101 //===--------------------------------------------------------------------===// 102 103 Value *VisitStmt(Stmt *S) { 104 S->dump(CGF.getContext().getSourceManager()); 105 assert(0 && "Stmt can't have complex result type!"); 106 return 0; 107 } 108 Value *VisitExpr(Expr *S); 109 110 Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); } 111 112 // Leaves. 113 Value *VisitIntegerLiteral(const IntegerLiteral *E) { 114 return llvm::ConstantInt::get(VMContext, E->getValue()); 115 } 116 Value *VisitFloatingLiteral(const FloatingLiteral *E) { 117 return llvm::ConstantFP::get(VMContext, E->getValue()); 118 } 119 Value *VisitCharacterLiteral(const CharacterLiteral *E) { 120 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 121 } 122 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 123 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 124 } 125 Value *VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) { 126 return llvm::Constant::getNullValue(ConvertType(E->getType())); 127 } 128 Value *VisitGNUNullExpr(const GNUNullExpr *E) { 129 return llvm::Constant::getNullValue(ConvertType(E->getType())); 130 } 131 Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { 132 return llvm::ConstantInt::get(ConvertType(E->getType()), 133 CGF.getContext().typesAreCompatible( 134 E->getArgType1(), E->getArgType2())); 135 } 136 Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); 137 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 138 llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel()); 139 return Builder.CreateBitCast(V, ConvertType(E->getType())); 140 } 141 142 // l-values. 143 Value *VisitDeclRefExpr(DeclRefExpr *E) { 144 Expr::EvalResult Result; 145 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 146 assert(!Result.HasSideEffects && "Constant declref with side-effect?!"); 147 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 148 } 149 return EmitLoadOfLValue(E); 150 } 151 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 152 return CGF.EmitObjCSelectorExpr(E); 153 } 154 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 155 return CGF.EmitObjCProtocolExpr(E); 156 } 157 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 158 return EmitLoadOfLValue(E); 159 } 160 Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { 161 return EmitLoadOfLValue(E); 162 } 163 Value *VisitObjCImplicitSetterGetterRefExpr( 164 ObjCImplicitSetterGetterRefExpr *E) { 165 return EmitLoadOfLValue(E); 166 } 167 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 168 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 169 } 170 171 Value *VisitObjCIsaExpr(ObjCIsaExpr *E) { 172 LValue LV = CGF.EmitObjCIsaExpr(E); 173 Value *V = CGF.EmitLoadOfLValue(LV, E->getType()).getScalarVal(); 174 return V; 175 } 176 177 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 178 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 179 Value *VisitMemberExpr(MemberExpr *E); 180 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 181 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 182 return EmitLoadOfLValue(E); 183 } 184 185 Value *VisitInitListExpr(InitListExpr *E); 186 187 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { 188 return llvm::Constant::getNullValue(ConvertType(E->getType())); 189 } 190 Value *VisitCastExpr(CastExpr *E) { 191 // Make sure to evaluate VLA bounds now so that we have them for later. 192 if (E->getType()->isVariablyModifiedType()) 193 CGF.EmitVLASize(E->getType()); 194 195 return EmitCastExpr(E); 196 } 197 Value *EmitCastExpr(CastExpr *E); 198 199 Value *VisitCallExpr(const CallExpr *E) { 200 if (E->getCallReturnType()->isReferenceType()) 201 return EmitLoadOfLValue(E); 202 203 return CGF.EmitCallExpr(E).getScalarVal(); 204 } 205 206 Value *VisitStmtExpr(const StmtExpr *E); 207 208 Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E); 209 210 // Unary Operators. 211 Value *VisitPrePostIncDec(const UnaryOperator *E, bool isInc, bool isPre) { 212 LValue LV = EmitLValue(E->getSubExpr()); 213 return CGF.EmitScalarPrePostIncDec(E, LV, isInc, isPre); 214 } 215 Value *VisitUnaryPostDec(const UnaryOperator *E) { 216 return VisitPrePostIncDec(E, false, false); 217 } 218 Value *VisitUnaryPostInc(const UnaryOperator *E) { 219 return VisitPrePostIncDec(E, true, false); 220 } 221 Value *VisitUnaryPreDec(const UnaryOperator *E) { 222 return VisitPrePostIncDec(E, false, true); 223 } 224 Value *VisitUnaryPreInc(const UnaryOperator *E) { 225 return VisitPrePostIncDec(E, true, true); 226 } 227 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 228 return EmitLValue(E->getSubExpr()).getAddress(); 229 } 230 Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } 231 Value *VisitUnaryPlus(const UnaryOperator *E) { 232 // This differs from gcc, though, most likely due to a bug in gcc. 233 TestAndClearIgnoreResultAssign(); 234 return Visit(E->getSubExpr()); 235 } 236 Value *VisitUnaryMinus (const UnaryOperator *E); 237 Value *VisitUnaryNot (const UnaryOperator *E); 238 Value *VisitUnaryLNot (const UnaryOperator *E); 239 Value *VisitUnaryReal (const UnaryOperator *E); 240 Value *VisitUnaryImag (const UnaryOperator *E); 241 Value *VisitUnaryExtension(const UnaryOperator *E) { 242 return Visit(E->getSubExpr()); 243 } 244 Value *VisitUnaryOffsetOf(const UnaryOperator *E); 245 246 // C++ 247 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 248 return Visit(DAE->getExpr()); 249 } 250 Value *VisitCXXThisExpr(CXXThisExpr *TE) { 251 return CGF.LoadCXXThis(); 252 } 253 254 Value *VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) { 255 return CGF.EmitCXXExprWithTemporaries(E).getScalarVal(); 256 } 257 Value *VisitCXXNewExpr(const CXXNewExpr *E) { 258 return CGF.EmitCXXNewExpr(E); 259 } 260 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { 261 CGF.EmitCXXDeleteExpr(E); 262 return 0; 263 } 264 Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) { 265 return llvm::ConstantInt::get(Builder.getInt1Ty(), 266 E->EvaluateTrait(CGF.getContext())); 267 } 268 269 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { 270 // C++ [expr.pseudo]p1: 271 // The result shall only be used as the operand for the function call 272 // operator (), and the result of such a call has type void. The only 273 // effect is the evaluation of the postfix-expression before the dot or 274 // arrow. 275 CGF.EmitScalarExpr(E->getBase()); 276 return 0; 277 } 278 279 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { 280 return llvm::Constant::getNullValue(ConvertType(E->getType())); 281 } 282 283 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { 284 CGF.EmitCXXThrowExpr(E); 285 return 0; 286 } 287 288 // Binary Operators. 289 Value *EmitMul(const BinOpInfo &Ops) { 290 if (CGF.getContext().getLangOptions().OverflowChecking 291 && Ops.Ty->isSignedIntegerType()) 292 return EmitOverflowCheckedBinOp(Ops); 293 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 294 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 295 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 296 } 297 /// Create a binary op that checks for overflow. 298 /// Currently only supports +, - and *. 299 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 300 Value *EmitDiv(const BinOpInfo &Ops); 301 Value *EmitRem(const BinOpInfo &Ops); 302 Value *EmitAdd(const BinOpInfo &Ops); 303 Value *EmitSub(const BinOpInfo &Ops); 304 Value *EmitShl(const BinOpInfo &Ops); 305 Value *EmitShr(const BinOpInfo &Ops); 306 Value *EmitAnd(const BinOpInfo &Ops) { 307 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 308 } 309 Value *EmitXor(const BinOpInfo &Ops) { 310 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 311 } 312 Value *EmitOr (const BinOpInfo &Ops) { 313 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 314 } 315 316 BinOpInfo EmitBinOps(const BinaryOperator *E); 317 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 318 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 319 320 // Binary operators and binary compound assignment operators. 321#define HANDLEBINOP(OP) \ 322 Value *VisitBin ## OP(const BinaryOperator *E) { \ 323 return Emit ## OP(EmitBinOps(E)); \ 324 } \ 325 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 326 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 327 } 328 HANDLEBINOP(Mul) 329 HANDLEBINOP(Div) 330 HANDLEBINOP(Rem) 331 HANDLEBINOP(Add) 332 HANDLEBINOP(Sub) 333 HANDLEBINOP(Shl) 334 HANDLEBINOP(Shr) 335 HANDLEBINOP(And) 336 HANDLEBINOP(Xor) 337 HANDLEBINOP(Or) 338#undef HANDLEBINOP 339 340 // Comparisons. 341 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 342 unsigned SICmpOpc, unsigned FCmpOpc); 343#define VISITCOMP(CODE, UI, SI, FP) \ 344 Value *VisitBin##CODE(const BinaryOperator *E) { \ 345 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 346 llvm::FCmpInst::FP); } 347 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT) 348 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT) 349 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE) 350 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE) 351 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ) 352 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE) 353#undef VISITCOMP 354 355 Value *VisitBinAssign (const BinaryOperator *E); 356 357 Value *VisitBinLAnd (const BinaryOperator *E); 358 Value *VisitBinLOr (const BinaryOperator *E); 359 Value *VisitBinComma (const BinaryOperator *E); 360 361 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } 362 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); } 363 364 // Other Operators. 365 Value *VisitBlockExpr(const BlockExpr *BE); 366 Value *VisitConditionalOperator(const ConditionalOperator *CO); 367 Value *VisitChooseExpr(ChooseExpr *CE); 368 Value *VisitVAArgExpr(VAArgExpr *VE); 369 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 370 return CGF.EmitObjCStringLiteral(E); 371 } 372}; 373} // end anonymous namespace. 374 375//===----------------------------------------------------------------------===// 376// Utilities 377//===----------------------------------------------------------------------===// 378 379/// EmitConversionToBool - Convert the specified expression value to a 380/// boolean (i1) truth value. This is equivalent to "Val != 0". 381Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 382 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs"); 383 384 if (SrcType->isRealFloatingType()) { 385 // Compare against 0.0 for fp scalars. 386 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 387 return Builder.CreateFCmpUNE(Src, Zero, "tobool"); 388 } 389 390 if (SrcType->isMemberPointerType()) { 391 // Compare against -1. 392 llvm::Value *NegativeOne = llvm::Constant::getAllOnesValue(Src->getType()); 393 return Builder.CreateICmpNE(Src, NegativeOne, "tobool"); 394 } 395 396 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 397 "Unknown scalar type to convert"); 398 399 // Because of the type rules of C, we often end up computing a logical value, 400 // then zero extending it to int, then wanting it as a logical value again. 401 // Optimize this common case. 402 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) { 403 if (ZI->getOperand(0)->getType() == 404 llvm::Type::getInt1Ty(CGF.getLLVMContext())) { 405 Value *Result = ZI->getOperand(0); 406 // If there aren't any more uses, zap the instruction to save space. 407 // Note that there can be more uses, for example if this 408 // is the result of an assignment. 409 if (ZI->use_empty()) 410 ZI->eraseFromParent(); 411 return Result; 412 } 413 } 414 415 // Compare against an integer or pointer null. 416 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 417 return Builder.CreateICmpNE(Src, Zero, "tobool"); 418} 419 420/// EmitScalarConversion - Emit a conversion from the specified type to the 421/// specified destination type, both of which are LLVM scalar types. 422Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 423 QualType DstType) { 424 SrcType = CGF.getContext().getCanonicalType(SrcType); 425 DstType = CGF.getContext().getCanonicalType(DstType); 426 if (SrcType == DstType) return Src; 427 428 if (DstType->isVoidType()) return 0; 429 430 llvm::LLVMContext &VMContext = CGF.getLLVMContext(); 431 432 // Handle conversions to bool first, they are special: comparisons against 0. 433 if (DstType->isBooleanType()) 434 return EmitConversionToBool(Src, SrcType); 435 436 const llvm::Type *DstTy = ConvertType(DstType); 437 438 // Ignore conversions like int -> uint. 439 if (Src->getType() == DstTy) 440 return Src; 441 442 // Handle pointer conversions next: pointers can only be converted to/from 443 // other pointers and integers. Check for pointer types in terms of LLVM, as 444 // some native types (like Obj-C id) may map to a pointer type. 445 if (isa<llvm::PointerType>(DstTy)) { 446 // The source value may be an integer, or a pointer. 447 if (isa<llvm::PointerType>(Src->getType())) 448 return Builder.CreateBitCast(Src, DstTy, "conv"); 449 450 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 451 // First, convert to the correct width so that we control the kind of 452 // extension. 453 const llvm::Type *MiddleTy = 454 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 455 bool InputSigned = SrcType->isSignedIntegerType(); 456 llvm::Value* IntResult = 457 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 458 // Then, cast to pointer. 459 return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); 460 } 461 462 if (isa<llvm::PointerType>(Src->getType())) { 463 // Must be an ptr to int cast. 464 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 465 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 466 } 467 468 // A scalar can be splatted to an extended vector of the same element type 469 if (DstType->isExtVectorType() && !SrcType->isVectorType()) { 470 // Cast the scalar to element type 471 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType(); 472 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 473 474 // Insert the element in element zero of an undef vector 475 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 476 llvm::Value *Idx = 477 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0); 478 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 479 480 // Splat the element across to all elements 481 llvm::SmallVector<llvm::Constant*, 16> Args; 482 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 483 for (unsigned i = 0; i < NumElements; i++) 484 Args.push_back(llvm::ConstantInt::get( 485 llvm::Type::getInt32Ty(VMContext), 0)); 486 487 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 488 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 489 return Yay; 490 } 491 492 // Allow bitcast from vector to integer/fp of the same size. 493 if (isa<llvm::VectorType>(Src->getType()) || 494 isa<llvm::VectorType>(DstTy)) 495 return Builder.CreateBitCast(Src, DstTy, "conv"); 496 497 // Finally, we have the arithmetic types: real int/float. 498 if (isa<llvm::IntegerType>(Src->getType())) { 499 bool InputSigned = SrcType->isSignedIntegerType(); 500 if (isa<llvm::IntegerType>(DstTy)) 501 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 502 else if (InputSigned) 503 return Builder.CreateSIToFP(Src, DstTy, "conv"); 504 else 505 return Builder.CreateUIToFP(Src, DstTy, "conv"); 506 } 507 508 assert(Src->getType()->isFloatingPointTy() && "Unknown real conversion"); 509 if (isa<llvm::IntegerType>(DstTy)) { 510 if (DstType->isSignedIntegerType()) 511 return Builder.CreateFPToSI(Src, DstTy, "conv"); 512 else 513 return Builder.CreateFPToUI(Src, DstTy, "conv"); 514 } 515 516 assert(DstTy->isFloatingPointTy() && "Unknown real conversion"); 517 if (DstTy->getTypeID() < Src->getType()->getTypeID()) 518 return Builder.CreateFPTrunc(Src, DstTy, "conv"); 519 else 520 return Builder.CreateFPExt(Src, DstTy, "conv"); 521} 522 523/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 524/// type to the specified destination type, where the destination type is an 525/// LLVM scalar type. 526Value *ScalarExprEmitter:: 527EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 528 QualType SrcTy, QualType DstTy) { 529 // Get the source element type. 530 SrcTy = SrcTy->getAs<ComplexType>()->getElementType(); 531 532 // Handle conversions to bool first, they are special: comparisons against 0. 533 if (DstTy->isBooleanType()) { 534 // Complex != 0 -> (Real != 0) | (Imag != 0) 535 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 536 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 537 return Builder.CreateOr(Src.first, Src.second, "tobool"); 538 } 539 540 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 541 // the imaginary part of the complex value is discarded and the value of the 542 // real part is converted according to the conversion rules for the 543 // corresponding real type. 544 return EmitScalarConversion(Src.first, SrcTy, DstTy); 545} 546 547 548//===----------------------------------------------------------------------===// 549// Visitor Methods 550//===----------------------------------------------------------------------===// 551 552Value *ScalarExprEmitter::VisitExpr(Expr *E) { 553 CGF.ErrorUnsupported(E, "scalar expression"); 554 if (E->getType()->isVoidType()) 555 return 0; 556 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 557} 558 559Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 560 llvm::SmallVector<llvm::Constant*, 32> indices; 561 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 562 indices.push_back(cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i)))); 563 } 564 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 565 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 566 Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); 567 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 568} 569Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { 570 Expr::EvalResult Result; 571 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 572 if (E->isArrow()) 573 CGF.EmitScalarExpr(E->getBase()); 574 else 575 EmitLValue(E->getBase()); 576 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 577 } 578 return EmitLoadOfLValue(E); 579} 580 581Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 582 TestAndClearIgnoreResultAssign(); 583 584 // Emit subscript expressions in rvalue context's. For most cases, this just 585 // loads the lvalue formed by the subscript expr. However, we have to be 586 // careful, because the base of a vector subscript is occasionally an rvalue, 587 // so we can't get it as an lvalue. 588 if (!E->getBase()->getType()->isVectorType()) 589 return EmitLoadOfLValue(E); 590 591 // Handle the vector case. The base must be a vector, the index must be an 592 // integer value. 593 Value *Base = Visit(E->getBase()); 594 Value *Idx = Visit(E->getIdx()); 595 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerType(); 596 Idx = Builder.CreateIntCast(Idx, 597 llvm::Type::getInt32Ty(CGF.getLLVMContext()), 598 IdxSigned, 599 "vecidxcast"); 600 return Builder.CreateExtractElement(Base, Idx, "vecext"); 601} 602 603static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, 604 unsigned Off, const llvm::Type *I32Ty) { 605 int MV = SVI->getMaskValue(Idx); 606 if (MV == -1) 607 return llvm::UndefValue::get(I32Ty); 608 return llvm::ConstantInt::get(I32Ty, Off+MV); 609} 610 611Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) { 612 bool Ignore = TestAndClearIgnoreResultAssign(); 613 (void)Ignore; 614 assert (Ignore == false && "init list ignored"); 615 unsigned NumInitElements = E->getNumInits(); 616 617 if (E->hadArrayRangeDesignator()) 618 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 619 620 const llvm::VectorType *VType = 621 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 622 623 // We have a scalar in braces. Just use the first element. 624 if (!VType) 625 return Visit(E->getInit(0)); 626 627 unsigned ResElts = VType->getNumElements(); 628 const llvm::Type *I32Ty = llvm::Type::getInt32Ty(CGF.getLLVMContext()); 629 630 // Loop over initializers collecting the Value for each, and remembering 631 // whether the source was swizzle (ExtVectorElementExpr). This will allow 632 // us to fold the shuffle for the swizzle into the shuffle for the vector 633 // initializer, since LLVM optimizers generally do not want to touch 634 // shuffles. 635 unsigned CurIdx = 0; 636 bool VIsUndefShuffle = false; 637 llvm::Value *V = llvm::UndefValue::get(VType); 638 for (unsigned i = 0; i != NumInitElements; ++i) { 639 Expr *IE = E->getInit(i); 640 Value *Init = Visit(IE); 641 llvm::SmallVector<llvm::Constant*, 16> Args; 642 643 const llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType()); 644 645 // Handle scalar elements. If the scalar initializer is actually one 646 // element of a different vector of the same width, use shuffle instead of 647 // extract+insert. 648 if (!VVT) { 649 if (isa<ExtVectorElementExpr>(IE)) { 650 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init); 651 652 if (EI->getVectorOperandType()->getNumElements() == ResElts) { 653 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand()); 654 Value *LHS = 0, *RHS = 0; 655 if (CurIdx == 0) { 656 // insert into undef -> shuffle (src, undef) 657 Args.push_back(C); 658 for (unsigned j = 1; j != ResElts; ++j) 659 Args.push_back(llvm::UndefValue::get(I32Ty)); 660 661 LHS = EI->getVectorOperand(); 662 RHS = V; 663 VIsUndefShuffle = true; 664 } else if (VIsUndefShuffle) { 665 // insert into undefshuffle && size match -> shuffle (v, src) 666 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V); 667 for (unsigned j = 0; j != CurIdx; ++j) 668 Args.push_back(getMaskElt(SVV, j, 0, I32Ty)); 669 Args.push_back(llvm::ConstantInt::get(I32Ty, 670 ResElts + C->getZExtValue())); 671 for (unsigned j = CurIdx + 1; j != ResElts; ++j) 672 Args.push_back(llvm::UndefValue::get(I32Ty)); 673 674 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 675 RHS = EI->getVectorOperand(); 676 VIsUndefShuffle = false; 677 } 678 if (!Args.empty()) { 679 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 680 V = Builder.CreateShuffleVector(LHS, RHS, Mask); 681 ++CurIdx; 682 continue; 683 } 684 } 685 } 686 Value *Idx = llvm::ConstantInt::get(I32Ty, CurIdx); 687 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 688 VIsUndefShuffle = false; 689 ++CurIdx; 690 continue; 691 } 692 693 unsigned InitElts = VVT->getNumElements(); 694 695 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's 696 // input is the same width as the vector being constructed, generate an 697 // optimized shuffle of the swizzle input into the result. 698 unsigned Offset = (CurIdx == 0) ? 0 : ResElts; 699 if (isa<ExtVectorElementExpr>(IE)) { 700 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init); 701 Value *SVOp = SVI->getOperand(0); 702 const llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType()); 703 704 if (OpTy->getNumElements() == ResElts) { 705 for (unsigned j = 0; j != CurIdx; ++j) { 706 // If the current vector initializer is a shuffle with undef, merge 707 // this shuffle directly into it. 708 if (VIsUndefShuffle) { 709 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0, 710 I32Ty)); 711 } else { 712 Args.push_back(llvm::ConstantInt::get(I32Ty, j)); 713 } 714 } 715 for (unsigned j = 0, je = InitElts; j != je; ++j) 716 Args.push_back(getMaskElt(SVI, j, Offset, I32Ty)); 717 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 718 Args.push_back(llvm::UndefValue::get(I32Ty)); 719 720 if (VIsUndefShuffle) 721 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 722 723 Init = SVOp; 724 } 725 } 726 727 // Extend init to result vector length, and then shuffle its contribution 728 // to the vector initializer into V. 729 if (Args.empty()) { 730 for (unsigned j = 0; j != InitElts; ++j) 731 Args.push_back(llvm::ConstantInt::get(I32Ty, j)); 732 for (unsigned j = InitElts; j != ResElts; ++j) 733 Args.push_back(llvm::UndefValue::get(I32Ty)); 734 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 735 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), 736 Mask, "vext"); 737 738 Args.clear(); 739 for (unsigned j = 0; j != CurIdx; ++j) 740 Args.push_back(llvm::ConstantInt::get(I32Ty, j)); 741 for (unsigned j = 0; j != InitElts; ++j) 742 Args.push_back(llvm::ConstantInt::get(I32Ty, j+Offset)); 743 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 744 Args.push_back(llvm::UndefValue::get(I32Ty)); 745 } 746 747 // If V is undef, make sure it ends up on the RHS of the shuffle to aid 748 // merging subsequent shuffles into this one. 749 if (CurIdx == 0) 750 std::swap(V, Init); 751 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 752 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); 753 VIsUndefShuffle = isa<llvm::UndefValue>(Init); 754 CurIdx += InitElts; 755 } 756 757 // FIXME: evaluate codegen vs. shuffling against constant null vector. 758 // Emit remaining default initializers. 759 const llvm::Type *EltTy = VType->getElementType(); 760 761 // Emit remaining default initializers 762 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { 763 Value *Idx = llvm::ConstantInt::get(I32Ty, CurIdx); 764 llvm::Value *Init = llvm::Constant::getNullValue(EltTy); 765 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 766 } 767 return V; 768} 769 770static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { 771 const Expr *E = CE->getSubExpr(); 772 773 if (isa<CXXThisExpr>(E)) { 774 // We always assume that 'this' is never null. 775 return false; 776 } 777 778 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { 779 // And that lvalue casts are never null. 780 if (ICE->isLvalueCast()) 781 return false; 782 } 783 784 return true; 785} 786 787// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 788// have to handle a more broad range of conversions than explicit casts, as they 789// handle things like function to ptr-to-function decay etc. 790Value *ScalarExprEmitter::EmitCastExpr(CastExpr *CE) { 791 Expr *E = CE->getSubExpr(); 792 QualType DestTy = CE->getType(); 793 CastExpr::CastKind Kind = CE->getCastKind(); 794 795 if (!DestTy->isVoidType()) 796 TestAndClearIgnoreResultAssign(); 797 798 // Since almost all cast kinds apply to scalars, this switch doesn't have 799 // a default case, so the compiler will warn on a missing case. The cases 800 // are in the same order as in the CastKind enum. 801 switch (Kind) { 802 case CastExpr::CK_Unknown: 803 // FIXME: All casts should have a known kind! 804 //assert(0 && "Unknown cast kind!"); 805 break; 806 807 case CastExpr::CK_AnyPointerToObjCPointerCast: 808 case CastExpr::CK_AnyPointerToBlockPointerCast: 809 case CastExpr::CK_BitCast: { 810 Value *Src = Visit(const_cast<Expr*>(E)); 811 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 812 } 813 case CastExpr::CK_NoOp: 814 case CastExpr::CK_UserDefinedConversion: 815 return Visit(const_cast<Expr*>(E)); 816 817 case CastExpr::CK_BaseToDerived: { 818 const CXXRecordDecl *BaseClassDecl = 819 E->getType()->getCXXRecordDeclForPointerType(); 820 const CXXRecordDecl *DerivedClassDecl = 821 DestTy->getCXXRecordDeclForPointerType(); 822 823 Value *Src = Visit(const_cast<Expr*>(E)); 824 825 bool NullCheckValue = ShouldNullCheckClassCastValue(CE); 826 return CGF.GetAddressOfDerivedClass(Src, BaseClassDecl, DerivedClassDecl, 827 NullCheckValue); 828 } 829 case CastExpr::CK_DerivedToBase: { 830 const RecordType *DerivedClassTy = 831 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 832 CXXRecordDecl *DerivedClassDecl = 833 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 834 835 const RecordType *BaseClassTy = 836 DestTy->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 837 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseClassTy->getDecl()); 838 839 Value *Src = Visit(const_cast<Expr*>(E)); 840 841 bool NullCheckValue = ShouldNullCheckClassCastValue(CE); 842 return CGF.GetAddressOfBaseClass(Src, DerivedClassDecl, BaseClassDecl, 843 NullCheckValue); 844 } 845 case CastExpr::CK_Dynamic: { 846 Value *V = Visit(const_cast<Expr*>(E)); 847 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 848 return CGF.EmitDynamicCast(V, DCE); 849 } 850 case CastExpr::CK_ToUnion: 851 assert(0 && "Should be unreachable!"); 852 break; 853 854 case CastExpr::CK_ArrayToPointerDecay: { 855 assert(E->getType()->isArrayType() && 856 "Array to pointer decay must have array source type!"); 857 858 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 859 860 // Note that VLA pointers are always decayed, so we don't need to do 861 // anything here. 862 if (!E->getType()->isVariableArrayType()) { 863 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 864 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 865 ->getElementType()) && 866 "Expected pointer to array"); 867 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 868 } 869 870 return V; 871 } 872 case CastExpr::CK_FunctionToPointerDecay: 873 return EmitLValue(E).getAddress(); 874 875 case CastExpr::CK_NullToMemberPointer: 876 return CGF.CGM.EmitNullConstant(DestTy); 877 878 case CastExpr::CK_BaseToDerivedMemberPointer: 879 case CastExpr::CK_DerivedToBaseMemberPointer: { 880 Value *Src = Visit(E); 881 882 // See if we need to adjust the pointer. 883 const CXXRecordDecl *BaseDecl = 884 cast<CXXRecordDecl>(E->getType()->getAs<MemberPointerType>()-> 885 getClass()->getAs<RecordType>()->getDecl()); 886 const CXXRecordDecl *DerivedDecl = 887 cast<CXXRecordDecl>(CE->getType()->getAs<MemberPointerType>()-> 888 getClass()->getAs<RecordType>()->getDecl()); 889 if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) 890 std::swap(DerivedDecl, BaseDecl); 891 892 if (llvm::Constant *Adj = 893 CGF.CGM.GetNonVirtualBaseClassOffset(DerivedDecl, BaseDecl)) { 894 if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) 895 Src = Builder.CreateSub(Src, Adj, "adj"); 896 else 897 Src = Builder.CreateAdd(Src, Adj, "adj"); 898 } 899 return Src; 900 } 901 902 case CastExpr::CK_ConstructorConversion: 903 assert(0 && "Should be unreachable!"); 904 break; 905 906 case CastExpr::CK_IntegralToPointer: { 907 Value *Src = Visit(const_cast<Expr*>(E)); 908 909 // First, convert to the correct width so that we control the kind of 910 // extension. 911 const llvm::Type *MiddleTy = 912 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 913 bool InputSigned = E->getType()->isSignedIntegerType(); 914 llvm::Value* IntResult = 915 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 916 917 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 918 } 919 case CastExpr::CK_PointerToIntegral: { 920 Value *Src = Visit(const_cast<Expr*>(E)); 921 return Builder.CreatePtrToInt(Src, ConvertType(DestTy)); 922 } 923 case CastExpr::CK_ToVoid: { 924 CGF.EmitAnyExpr(E, 0, false, true); 925 return 0; 926 } 927 case CastExpr::CK_VectorSplat: { 928 const llvm::Type *DstTy = ConvertType(DestTy); 929 Value *Elt = Visit(const_cast<Expr*>(E)); 930 931 // Insert the element in element zero of an undef vector 932 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 933 llvm::Value *Idx = 934 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0); 935 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 936 937 // Splat the element across to all elements 938 llvm::SmallVector<llvm::Constant*, 16> Args; 939 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 940 for (unsigned i = 0; i < NumElements; i++) 941 Args.push_back(llvm::ConstantInt::get( 942 llvm::Type::getInt32Ty(VMContext), 0)); 943 944 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 945 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 946 return Yay; 947 } 948 case CastExpr::CK_IntegralCast: 949 case CastExpr::CK_IntegralToFloating: 950 case CastExpr::CK_FloatingToIntegral: 951 case CastExpr::CK_FloatingCast: 952 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 953 954 case CastExpr::CK_MemberPointerToBoolean: 955 return CGF.EvaluateExprAsBool(E); 956 } 957 958 // Handle cases where the source is an non-complex type. 959 960 if (!CGF.hasAggregateLLVMType(E->getType())) { 961 Value *Src = Visit(const_cast<Expr*>(E)); 962 963 // Use EmitScalarConversion to perform the conversion. 964 return EmitScalarConversion(Src, E->getType(), DestTy); 965 } 966 967 if (E->getType()->isAnyComplexType()) { 968 // Handle cases where the source is a complex type. 969 bool IgnoreImag = true; 970 bool IgnoreImagAssign = true; 971 bool IgnoreReal = IgnoreResultAssign; 972 bool IgnoreRealAssign = IgnoreResultAssign; 973 if (DestTy->isBooleanType()) 974 IgnoreImagAssign = IgnoreImag = false; 975 else if (DestTy->isVoidType()) { 976 IgnoreReal = IgnoreImag = false; 977 IgnoreRealAssign = IgnoreImagAssign = true; 978 } 979 CodeGenFunction::ComplexPairTy V 980 = CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign, 981 IgnoreImagAssign); 982 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 983 } 984 985 // Okay, this is a cast from an aggregate. It must be a cast to void. Just 986 // evaluate the result and return. 987 CGF.EmitAggExpr(E, 0, false, true); 988 return 0; 989} 990 991Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 992 return CGF.EmitCompoundStmt(*E->getSubStmt(), 993 !E->getType()->isVoidType()).getScalarVal(); 994} 995 996Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 997 llvm::Value *V = CGF.GetAddrOfBlockDecl(E); 998 if (E->getType().isObjCGCWeak()) 999 return CGF.CGM.getObjCRuntime().EmitObjCWeakRead(CGF, V); 1000 return Builder.CreateLoad(V, "tmp"); 1001} 1002 1003//===----------------------------------------------------------------------===// 1004// Unary Operators 1005//===----------------------------------------------------------------------===// 1006 1007Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1008 TestAndClearIgnoreResultAssign(); 1009 Value *Op = Visit(E->getSubExpr()); 1010 if (Op->getType()->isFPOrFPVectorTy()) 1011 return Builder.CreateFNeg(Op, "neg"); 1012 return Builder.CreateNeg(Op, "neg"); 1013} 1014 1015Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1016 TestAndClearIgnoreResultAssign(); 1017 Value *Op = Visit(E->getSubExpr()); 1018 return Builder.CreateNot(Op, "neg"); 1019} 1020 1021Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1022 // Compare operand to zero. 1023 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1024 1025 // Invert value. 1026 // TODO: Could dynamically modify easy computations here. For example, if 1027 // the operand is an icmp ne, turn into icmp eq. 1028 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1029 1030 // ZExt result to the expr type. 1031 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1032} 1033 1034/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of 1035/// argument of the sizeof expression as an integer. 1036Value * 1037ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { 1038 QualType TypeToSize = E->getTypeOfArgument(); 1039 if (E->isSizeOf()) { 1040 if (const VariableArrayType *VAT = 1041 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1042 if (E->isArgumentType()) { 1043 // sizeof(type) - make sure to emit the VLA size. 1044 CGF.EmitVLASize(TypeToSize); 1045 } else { 1046 // C99 6.5.3.4p2: If the argument is an expression of type 1047 // VLA, it is evaluated. 1048 CGF.EmitAnyExpr(E->getArgumentExpr()); 1049 } 1050 1051 return CGF.GetVLASize(VAT); 1052 } 1053 } 1054 1055 // If this isn't sizeof(vla), the result must be constant; use the constant 1056 // folding logic so we don't have to duplicate it here. 1057 Expr::EvalResult Result; 1058 E->Evaluate(Result, CGF.getContext()); 1059 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 1060} 1061 1062Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1063 Expr *Op = E->getSubExpr(); 1064 if (Op->getType()->isAnyComplexType()) 1065 return CGF.EmitComplexExpr(Op, false, true, false, true).first; 1066 return Visit(Op); 1067} 1068Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1069 Expr *Op = E->getSubExpr(); 1070 if (Op->getType()->isAnyComplexType()) 1071 return CGF.EmitComplexExpr(Op, true, false, true, false).second; 1072 1073 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1074 // effects are evaluated, but not the actual value. 1075 if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) 1076 CGF.EmitLValue(Op); 1077 else 1078 CGF.EmitScalarExpr(Op, true); 1079 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1080} 1081 1082Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) { 1083 Value* ResultAsPtr = EmitLValue(E->getSubExpr()).getAddress(); 1084 const llvm::Type* ResultType = ConvertType(E->getType()); 1085 return Builder.CreatePtrToInt(ResultAsPtr, ResultType, "offsetof"); 1086} 1087 1088//===----------------------------------------------------------------------===// 1089// Binary Operators 1090//===----------------------------------------------------------------------===// 1091 1092BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1093 TestAndClearIgnoreResultAssign(); 1094 BinOpInfo Result; 1095 Result.LHS = Visit(E->getLHS()); 1096 Result.RHS = Visit(E->getRHS()); 1097 Result.Ty = E->getType(); 1098 Result.E = E; 1099 return Result; 1100} 1101 1102Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 1103 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 1104 bool Ignore = TestAndClearIgnoreResultAssign(); 1105 QualType LHSTy = E->getLHS()->getType(); 1106 1107 BinOpInfo OpInfo; 1108 1109 if (E->getComputationResultType()->isAnyComplexType()) { 1110 // This needs to go through the complex expression emitter, but it's a tad 1111 // complicated to do that... I'm leaving it out for now. (Note that we do 1112 // actually need the imaginary part of the RHS for multiplication and 1113 // division.) 1114 CGF.ErrorUnsupported(E, "complex compound assignment"); 1115 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 1116 } 1117 1118 // Emit the RHS first. __block variables need to have the rhs evaluated 1119 // first, plus this should improve codegen a little. 1120 OpInfo.RHS = Visit(E->getRHS()); 1121 OpInfo.Ty = E->getComputationResultType(); 1122 OpInfo.E = E; 1123 // Load/convert the LHS. 1124 LValue LHSLV = EmitCheckedLValue(E->getLHS()); 1125 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 1126 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 1127 E->getComputationLHSType()); 1128 1129 // Expand the binary operator. 1130 Value *Result = (this->*Func)(OpInfo); 1131 1132 // Convert the result back to the LHS type. 1133 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 1134 1135 // Store the result value into the LHS lvalue. Bit-fields are handled 1136 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 1137 // 'An assignment expression has the value of the left operand after the 1138 // assignment...'. 1139 if (LHSLV.isBitfield()) { 1140 if (!LHSLV.isVolatileQualified()) { 1141 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, 1142 &Result); 1143 return Result; 1144 } else 1145 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy); 1146 } else 1147 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); 1148 if (Ignore) 1149 return 0; 1150 return EmitLoadOfLValue(LHSLV, E->getType()); 1151} 1152 1153 1154Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 1155 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1156 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 1157 else if (Ops.Ty->isUnsignedIntegerType()) 1158 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 1159 else 1160 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 1161} 1162 1163Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 1164 // Rem in C can't be a floating point type: C99 6.5.5p2. 1165 if (Ops.Ty->isUnsignedIntegerType()) 1166 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 1167 else 1168 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 1169} 1170 1171Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 1172 unsigned IID; 1173 unsigned OpID = 0; 1174 1175 switch (Ops.E->getOpcode()) { 1176 case BinaryOperator::Add: 1177 case BinaryOperator::AddAssign: 1178 OpID = 1; 1179 IID = llvm::Intrinsic::sadd_with_overflow; 1180 break; 1181 case BinaryOperator::Sub: 1182 case BinaryOperator::SubAssign: 1183 OpID = 2; 1184 IID = llvm::Intrinsic::ssub_with_overflow; 1185 break; 1186 case BinaryOperator::Mul: 1187 case BinaryOperator::MulAssign: 1188 OpID = 3; 1189 IID = llvm::Intrinsic::smul_with_overflow; 1190 break; 1191 default: 1192 assert(false && "Unsupported operation for overflow detection"); 1193 IID = 0; 1194 } 1195 OpID <<= 1; 1196 OpID |= 1; 1197 1198 const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1199 1200 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1); 1201 1202 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1203 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1204 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1205 1206 // Branch in case of overflow. 1207 llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); 1208 llvm::BasicBlock *overflowBB = 1209 CGF.createBasicBlock("overflow", CGF.CurFn); 1210 llvm::BasicBlock *continueBB = 1211 CGF.createBasicBlock("overflow.continue", CGF.CurFn); 1212 1213 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1214 1215 // Handle overflow 1216 1217 Builder.SetInsertPoint(overflowBB); 1218 1219 // Handler is: 1220 // long long *__overflow_handler)(long long a, long long b, char op, 1221 // char width) 1222 std::vector<const llvm::Type*> handerArgTypes; 1223 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1224 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1225 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1226 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1227 llvm::FunctionType *handlerTy = llvm::FunctionType::get( 1228 llvm::Type::getInt64Ty(VMContext), handerArgTypes, false); 1229 llvm::Value *handlerFunction = 1230 CGF.CGM.getModule().getOrInsertGlobal("__overflow_handler", 1231 llvm::PointerType::getUnqual(handlerTy)); 1232 handlerFunction = Builder.CreateLoad(handlerFunction); 1233 1234 llvm::Value *handlerResult = Builder.CreateCall4(handlerFunction, 1235 Builder.CreateSExt(Ops.LHS, llvm::Type::getInt64Ty(VMContext)), 1236 Builder.CreateSExt(Ops.RHS, llvm::Type::getInt64Ty(VMContext)), 1237 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), OpID), 1238 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), 1239 cast<llvm::IntegerType>(opTy)->getBitWidth())); 1240 1241 handlerResult = Builder.CreateTrunc(handlerResult, opTy); 1242 1243 Builder.CreateBr(continueBB); 1244 1245 // Set up the continuation 1246 Builder.SetInsertPoint(continueBB); 1247 // Get the correct result 1248 llvm::PHINode *phi = Builder.CreatePHI(opTy); 1249 phi->reserveOperandSpace(2); 1250 phi->addIncoming(result, initialBB); 1251 phi->addIncoming(handlerResult, overflowBB); 1252 1253 return phi; 1254} 1255 1256Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 1257 if (!Ops.Ty->isAnyPointerType()) { 1258 if (CGF.getContext().getLangOptions().OverflowChecking && 1259 Ops.Ty->isSignedIntegerType()) 1260 return EmitOverflowCheckedBinOp(Ops); 1261 1262 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1263 return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add"); 1264 1265 // Signed integer overflow is undefined behavior. 1266 if (Ops.Ty->isSignedIntegerType()) 1267 return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add"); 1268 1269 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1270 } 1271 1272 if (Ops.Ty->isPointerType() && 1273 Ops.Ty->getAs<PointerType>()->isVariableArrayType()) { 1274 // The amount of the addition needs to account for the VLA size 1275 CGF.ErrorUnsupported(Ops.E, "VLA pointer addition"); 1276 } 1277 Value *Ptr, *Idx; 1278 Expr *IdxExp; 1279 const PointerType *PT = Ops.E->getLHS()->getType()->getAs<PointerType>(); 1280 const ObjCObjectPointerType *OPT = 1281 Ops.E->getLHS()->getType()->getAs<ObjCObjectPointerType>(); 1282 if (PT || OPT) { 1283 Ptr = Ops.LHS; 1284 Idx = Ops.RHS; 1285 IdxExp = Ops.E->getRHS(); 1286 } else { // int + pointer 1287 PT = Ops.E->getRHS()->getType()->getAs<PointerType>(); 1288 OPT = Ops.E->getRHS()->getType()->getAs<ObjCObjectPointerType>(); 1289 assert((PT || OPT) && "Invalid add expr"); 1290 Ptr = Ops.RHS; 1291 Idx = Ops.LHS; 1292 IdxExp = Ops.E->getLHS(); 1293 } 1294 1295 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1296 if (Width < CGF.LLVMPointerWidth) { 1297 // Zero or sign extend the pointer value based on whether the index is 1298 // signed or not. 1299 const llvm::Type *IdxType = 1300 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1301 if (IdxExp->getType()->isSignedIntegerType()) 1302 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1303 else 1304 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1305 } 1306 const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType(); 1307 // Handle interface types, which are not represented with a concrete type. 1308 if (const ObjCInterfaceType *OIT = dyn_cast<ObjCInterfaceType>(ElementType)) { 1309 llvm::Value *InterfaceSize = 1310 llvm::ConstantInt::get(Idx->getType(), 1311 CGF.getContext().getTypeSizeInChars(OIT).getQuantity()); 1312 Idx = Builder.CreateMul(Idx, InterfaceSize); 1313 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1314 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1315 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1316 return Builder.CreateBitCast(Res, Ptr->getType()); 1317 } 1318 1319 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 1320 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 1321 // future proof. 1322 if (ElementType->isVoidType() || ElementType->isFunctionType()) { 1323 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1324 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1325 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1326 return Builder.CreateBitCast(Res, Ptr->getType()); 1327 } 1328 1329 return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr"); 1330} 1331 1332Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 1333 if (!isa<llvm::PointerType>(Ops.LHS->getType())) { 1334 if (CGF.getContext().getLangOptions().OverflowChecking 1335 && Ops.Ty->isSignedIntegerType()) 1336 return EmitOverflowCheckedBinOp(Ops); 1337 1338 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1339 return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub"); 1340 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1341 } 1342 1343 if (Ops.E->getLHS()->getType()->isPointerType() && 1344 Ops.E->getLHS()->getType()->getAs<PointerType>()->isVariableArrayType()) { 1345 // The amount of the addition needs to account for the VLA size for 1346 // ptr-int 1347 // The amount of the division needs to account for the VLA size for 1348 // ptr-ptr. 1349 CGF.ErrorUnsupported(Ops.E, "VLA pointer subtraction"); 1350 } 1351 1352 const QualType LHSType = Ops.E->getLHS()->getType(); 1353 const QualType LHSElementType = LHSType->getPointeeType(); 1354 if (!isa<llvm::PointerType>(Ops.RHS->getType())) { 1355 // pointer - int 1356 Value *Idx = Ops.RHS; 1357 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1358 if (Width < CGF.LLVMPointerWidth) { 1359 // Zero or sign extend the pointer value based on whether the index is 1360 // signed or not. 1361 const llvm::Type *IdxType = 1362 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1363 if (Ops.E->getRHS()->getType()->isSignedIntegerType()) 1364 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1365 else 1366 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1367 } 1368 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); 1369 1370 // Handle interface types, which are not represented with a concrete type. 1371 if (const ObjCInterfaceType *OIT = 1372 dyn_cast<ObjCInterfaceType>(LHSElementType)) { 1373 llvm::Value *InterfaceSize = 1374 llvm::ConstantInt::get(Idx->getType(), 1375 CGF.getContext(). 1376 getTypeSizeInChars(OIT).getQuantity()); 1377 Idx = Builder.CreateMul(Idx, InterfaceSize); 1378 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1379 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1380 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr"); 1381 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1382 } 1383 1384 // Explicitly handle GNU void* and function pointer arithmetic 1385 // extensions. The GNU void* casts amount to no-ops since our void* type is 1386 // i8*, but this is future proof. 1387 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1388 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1389 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1390 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); 1391 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1392 } 1393 1394 return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr"); 1395 } else { 1396 // pointer - pointer 1397 Value *LHS = Ops.LHS; 1398 Value *RHS = Ops.RHS; 1399 1400 CharUnits ElementSize; 1401 1402 // Handle GCC extension for pointer arithmetic on void* and function pointer 1403 // types. 1404 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1405 ElementSize = CharUnits::One(); 1406 } else { 1407 ElementSize = CGF.getContext().getTypeSizeInChars(LHSElementType); 1408 } 1409 1410 const llvm::Type *ResultType = ConvertType(Ops.Ty); 1411 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 1412 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 1413 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 1414 1415 // Optimize out the shift for element size of 1. 1416 if (ElementSize.isOne()) 1417 return BytesBetween; 1418 1419 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 1420 // pointer difference in C is only defined in the case where both operands 1421 // are pointing to elements of an array. 1422 Value *BytesPerElt = 1423 llvm::ConstantInt::get(ResultType, ElementSize.getQuantity()); 1424 return Builder.CreateExactSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 1425 } 1426} 1427 1428Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 1429 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1430 // RHS to the same size as the LHS. 1431 Value *RHS = Ops.RHS; 1432 if (Ops.LHS->getType() != RHS->getType()) 1433 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1434 1435 if (CGF.CatchUndefined 1436 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1437 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1438 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1439 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1440 llvm::ConstantInt::get(RHS->getType(), Width)), 1441 Cont, CGF.getTrapBB()); 1442 CGF.EmitBlock(Cont); 1443 } 1444 1445 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 1446} 1447 1448Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 1449 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1450 // RHS to the same size as the LHS. 1451 Value *RHS = Ops.RHS; 1452 if (Ops.LHS->getType() != RHS->getType()) 1453 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1454 1455 if (CGF.CatchUndefined 1456 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1457 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1458 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1459 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1460 llvm::ConstantInt::get(RHS->getType(), Width)), 1461 Cont, CGF.getTrapBB()); 1462 CGF.EmitBlock(Cont); 1463 } 1464 1465 if (Ops.Ty->isUnsignedIntegerType()) 1466 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 1467 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 1468} 1469 1470Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 1471 unsigned SICmpOpc, unsigned FCmpOpc) { 1472 TestAndClearIgnoreResultAssign(); 1473 Value *Result; 1474 QualType LHSTy = E->getLHS()->getType(); 1475 if (LHSTy->isMemberFunctionPointerType()) { 1476 Value *LHSPtr = CGF.EmitAnyExprToTemp(E->getLHS()).getAggregateAddr(); 1477 Value *RHSPtr = CGF.EmitAnyExprToTemp(E->getRHS()).getAggregateAddr(); 1478 llvm::Value *LHSFunc = Builder.CreateStructGEP(LHSPtr, 0); 1479 LHSFunc = Builder.CreateLoad(LHSFunc); 1480 llvm::Value *RHSFunc = Builder.CreateStructGEP(RHSPtr, 0); 1481 RHSFunc = Builder.CreateLoad(RHSFunc); 1482 Value *ResultF = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1483 LHSFunc, RHSFunc, "cmp.func"); 1484 Value *NullPtr = llvm::Constant::getNullValue(LHSFunc->getType()); 1485 Value *ResultNull = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1486 LHSFunc, NullPtr, "cmp.null"); 1487 llvm::Value *LHSAdj = Builder.CreateStructGEP(LHSPtr, 1); 1488 LHSAdj = Builder.CreateLoad(LHSAdj); 1489 llvm::Value *RHSAdj = Builder.CreateStructGEP(RHSPtr, 1); 1490 RHSAdj = Builder.CreateLoad(RHSAdj); 1491 Value *ResultA = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1492 LHSAdj, RHSAdj, "cmp.adj"); 1493 if (E->getOpcode() == BinaryOperator::EQ) { 1494 Result = Builder.CreateOr(ResultNull, ResultA, "or.na"); 1495 Result = Builder.CreateAnd(Result, ResultF, "and.f"); 1496 } else { 1497 assert(E->getOpcode() == BinaryOperator::NE && 1498 "Member pointer comparison other than == or != ?"); 1499 Result = Builder.CreateAnd(ResultNull, ResultA, "and.na"); 1500 Result = Builder.CreateOr(Result, ResultF, "or.f"); 1501 } 1502 } else if (!LHSTy->isAnyComplexType()) { 1503 Value *LHS = Visit(E->getLHS()); 1504 Value *RHS = Visit(E->getRHS()); 1505 1506 if (LHS->getType()->isFPOrFPVectorTy()) { 1507 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 1508 LHS, RHS, "cmp"); 1509 } else if (LHSTy->isSignedIntegerType()) { 1510 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 1511 LHS, RHS, "cmp"); 1512 } else { 1513 // Unsigned integers and pointers. 1514 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1515 LHS, RHS, "cmp"); 1516 } 1517 1518 // If this is a vector comparison, sign extend the result to the appropriate 1519 // vector integer type and return it (don't convert to bool). 1520 if (LHSTy->isVectorType()) 1521 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 1522 1523 } else { 1524 // Complex Comparison: can only be an equality comparison. 1525 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 1526 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 1527 1528 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 1529 1530 Value *ResultR, *ResultI; 1531 if (CETy->isRealFloatingType()) { 1532 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1533 LHS.first, RHS.first, "cmp.r"); 1534 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1535 LHS.second, RHS.second, "cmp.i"); 1536 } else { 1537 // Complex comparisons can only be equality comparisons. As such, signed 1538 // and unsigned opcodes are the same. 1539 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1540 LHS.first, RHS.first, "cmp.r"); 1541 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1542 LHS.second, RHS.second, "cmp.i"); 1543 } 1544 1545 if (E->getOpcode() == BinaryOperator::EQ) { 1546 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 1547 } else { 1548 assert(E->getOpcode() == BinaryOperator::NE && 1549 "Complex comparison other than == or != ?"); 1550 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 1551 } 1552 } 1553 1554 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 1555} 1556 1557Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 1558 bool Ignore = TestAndClearIgnoreResultAssign(); 1559 1560 // __block variables need to have the rhs evaluated first, plus this should 1561 // improve codegen just a little. 1562 Value *RHS = Visit(E->getRHS()); 1563 LValue LHS = EmitCheckedLValue(E->getLHS()); 1564 1565 // Store the value into the LHS. Bit-fields are handled specially 1566 // because the result is altered by the store, i.e., [C99 6.5.16p1] 1567 // 'An assignment expression has the value of the left operand after 1568 // the assignment...'. 1569 if (LHS.isBitfield()) { 1570 if (!LHS.isVolatileQualified()) { 1571 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), 1572 &RHS); 1573 return RHS; 1574 } else 1575 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType()); 1576 } else 1577 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 1578 if (Ignore) 1579 return 0; 1580 return EmitLoadOfLValue(LHS, E->getType()); 1581} 1582 1583Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 1584 const llvm::Type *ResTy = ConvertType(E->getType()); 1585 1586 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 1587 // If we have 1 && X, just emit X without inserting the control flow. 1588 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1589 if (Cond == 1) { // If we have 1 && X, just emit X. 1590 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1591 // ZExt result to int or bool. 1592 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 1593 } 1594 1595 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 1596 if (!CGF.ContainsLabel(E->getRHS())) 1597 return llvm::Constant::getNullValue(ResTy); 1598 } 1599 1600 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 1601 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 1602 1603 // Branch on the LHS first. If it is false, go to the failure (cont) block. 1604 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 1605 1606 // Any edges into the ContBlock are now from an (indeterminate number of) 1607 // edges from this first condition. All of these values will be false. Start 1608 // setting up the PHI node in the Cont Block for this. 1609 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1610 "", ContBlock); 1611 PN->reserveOperandSpace(2); // Normal case, two inputs. 1612 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1613 PI != PE; ++PI) 1614 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 1615 1616 CGF.BeginConditionalBranch(); 1617 CGF.EmitBlock(RHSBlock); 1618 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1619 CGF.EndConditionalBranch(); 1620 1621 // Reaquire the RHS block, as there may be subblocks inserted. 1622 RHSBlock = Builder.GetInsertBlock(); 1623 1624 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1625 // into the phi node for the edge with the value of RHSCond. 1626 CGF.EmitBlock(ContBlock); 1627 PN->addIncoming(RHSCond, RHSBlock); 1628 1629 // ZExt result to int. 1630 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); 1631} 1632 1633Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 1634 const llvm::Type *ResTy = ConvertType(E->getType()); 1635 1636 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 1637 // If we have 0 || X, just emit X without inserting the control flow. 1638 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1639 if (Cond == -1) { // If we have 0 || X, just emit X. 1640 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1641 // ZExt result to int or bool. 1642 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 1643 } 1644 1645 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 1646 if (!CGF.ContainsLabel(E->getRHS())) 1647 return llvm::ConstantInt::get(ResTy, 1); 1648 } 1649 1650 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 1651 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 1652 1653 // Branch on the LHS first. If it is true, go to the success (cont) block. 1654 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 1655 1656 // Any edges into the ContBlock are now from an (indeterminate number of) 1657 // edges from this first condition. All of these values will be true. Start 1658 // setting up the PHI node in the Cont Block for this. 1659 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1660 "", ContBlock); 1661 PN->reserveOperandSpace(2); // Normal case, two inputs. 1662 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1663 PI != PE; ++PI) 1664 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 1665 1666 CGF.BeginConditionalBranch(); 1667 1668 // Emit the RHS condition as a bool value. 1669 CGF.EmitBlock(RHSBlock); 1670 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1671 1672 CGF.EndConditionalBranch(); 1673 1674 // Reaquire the RHS block, as there may be subblocks inserted. 1675 RHSBlock = Builder.GetInsertBlock(); 1676 1677 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1678 // into the phi node for the edge with the value of RHSCond. 1679 CGF.EmitBlock(ContBlock); 1680 PN->addIncoming(RHSCond, RHSBlock); 1681 1682 // ZExt result to int. 1683 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 1684} 1685 1686Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 1687 CGF.EmitStmt(E->getLHS()); 1688 CGF.EnsureInsertPoint(); 1689 return Visit(E->getRHS()); 1690} 1691 1692//===----------------------------------------------------------------------===// 1693// Other Operators 1694//===----------------------------------------------------------------------===// 1695 1696/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 1697/// expression is cheap enough and side-effect-free enough to evaluate 1698/// unconditionally instead of conditionally. This is used to convert control 1699/// flow into selects in some cases. 1700static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 1701 CodeGenFunction &CGF) { 1702 if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) 1703 return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr(), CGF); 1704 1705 // TODO: Allow anything we can constant fold to an integer or fp constant. 1706 if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || 1707 isa<FloatingLiteral>(E)) 1708 return true; 1709 1710 // Non-volatile automatic variables too, to get "cond ? X : Y" where 1711 // X and Y are local variables. 1712 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 1713 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 1714 if (VD->hasLocalStorage() && !(CGF.getContext() 1715 .getCanonicalType(VD->getType()) 1716 .isVolatileQualified())) 1717 return true; 1718 1719 return false; 1720} 1721 1722 1723Value *ScalarExprEmitter:: 1724VisitConditionalOperator(const ConditionalOperator *E) { 1725 TestAndClearIgnoreResultAssign(); 1726 // If the condition constant folds and can be elided, try to avoid emitting 1727 // the condition and the dead arm. 1728 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ 1729 Expr *Live = E->getLHS(), *Dead = E->getRHS(); 1730 if (Cond == -1) 1731 std::swap(Live, Dead); 1732 1733 // If the dead side doesn't have labels we need, and if the Live side isn't 1734 // the gnu missing ?: extension (which we could handle, but don't bother 1735 // to), just emit the Live part. 1736 if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part 1737 Live) // Live part isn't missing. 1738 return Visit(Live); 1739 } 1740 1741 1742 // If this is a really simple expression (like x ? 4 : 5), emit this as a 1743 // select instead of as control flow. We can only do this if it is cheap and 1744 // safe to evaluate the LHS and RHS unconditionally. 1745 if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS(), 1746 CGF) && 1747 isCheapEnoughToEvaluateUnconditionally(E->getRHS(), CGF)) { 1748 llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); 1749 llvm::Value *LHS = Visit(E->getLHS()); 1750 llvm::Value *RHS = Visit(E->getRHS()); 1751 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 1752 } 1753 1754 1755 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 1756 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 1757 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 1758 Value *CondVal = 0; 1759 1760 // If we don't have the GNU missing condition extension, emit a branch on bool 1761 // the normal way. 1762 if (E->getLHS()) { 1763 // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for 1764 // the branch on bool. 1765 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); 1766 } else { 1767 // Otherwise, for the ?: extension, evaluate the conditional and then 1768 // convert it to bool the hard way. We do this explicitly because we need 1769 // the unconverted value for the missing middle value of the ?:. 1770 CondVal = CGF.EmitScalarExpr(E->getCond()); 1771 1772 // In some cases, EmitScalarConversion will delete the "CondVal" expression 1773 // if there are no extra uses (an optimization). Inhibit this by making an 1774 // extra dead use, because we're going to add a use of CondVal later. We 1775 // don't use the builder for this, because we don't want it to get optimized 1776 // away. This leaves dead code, but the ?: extension isn't common. 1777 new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", 1778 Builder.GetInsertBlock()); 1779 1780 Value *CondBoolVal = 1781 CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 1782 CGF.getContext().BoolTy); 1783 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 1784 } 1785 1786 CGF.BeginConditionalBranch(); 1787 CGF.EmitBlock(LHSBlock); 1788 1789 // Handle the GNU extension for missing LHS. 1790 Value *LHS; 1791 if (E->getLHS()) 1792 LHS = Visit(E->getLHS()); 1793 else // Perform promotions, to handle cases like "short ?: int" 1794 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); 1795 1796 CGF.EndConditionalBranch(); 1797 LHSBlock = Builder.GetInsertBlock(); 1798 CGF.EmitBranch(ContBlock); 1799 1800 CGF.BeginConditionalBranch(); 1801 CGF.EmitBlock(RHSBlock); 1802 1803 Value *RHS = Visit(E->getRHS()); 1804 CGF.EndConditionalBranch(); 1805 RHSBlock = Builder.GetInsertBlock(); 1806 CGF.EmitBranch(ContBlock); 1807 1808 CGF.EmitBlock(ContBlock); 1809 1810 // If the LHS or RHS is a throw expression, it will be legitimately null. 1811 if (!LHS) 1812 return RHS; 1813 if (!RHS) 1814 return LHS; 1815 1816 // Create a PHI node for the real part. 1817 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 1818 PN->reserveOperandSpace(2); 1819 PN->addIncoming(LHS, LHSBlock); 1820 PN->addIncoming(RHS, RHSBlock); 1821 return PN; 1822} 1823 1824Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 1825 return Visit(E->getChosenSubExpr(CGF.getContext())); 1826} 1827 1828Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 1829 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 1830 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 1831 1832 // If EmitVAArg fails, we fall back to the LLVM instruction. 1833 if (!ArgPtr) 1834 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 1835 1836 // FIXME Volatility. 1837 return Builder.CreateLoad(ArgPtr); 1838} 1839 1840Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { 1841 return CGF.BuildBlockLiteralTmp(BE); 1842} 1843 1844//===----------------------------------------------------------------------===// 1845// Entry Point into this File 1846//===----------------------------------------------------------------------===// 1847 1848/// EmitScalarExpr - Emit the computation of the specified expression of scalar 1849/// type, ignoring the result. 1850Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 1851 assert(E && !hasAggregateLLVMType(E->getType()) && 1852 "Invalid scalar expression to emit"); 1853 1854 return ScalarExprEmitter(*this, IgnoreResultAssign) 1855 .Visit(const_cast<Expr*>(E)); 1856} 1857 1858/// EmitScalarConversion - Emit a conversion from the specified type to the 1859/// specified destination type, both of which are LLVM scalar types. 1860Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 1861 QualType DstTy) { 1862 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 1863 "Invalid scalar expression to emit"); 1864 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 1865} 1866 1867/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 1868/// type to the specified destination type, where the destination type is an 1869/// LLVM scalar type. 1870Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 1871 QualType SrcTy, 1872 QualType DstTy) { 1873 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 1874 "Invalid complex -> scalar conversion"); 1875 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 1876 DstTy); 1877} 1878 1879LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) { 1880 llvm::Value *V; 1881 // object->isa or (*object).isa 1882 // Generate code as for: *(Class*)object 1883 // build Class* type 1884 const llvm::Type *ClassPtrTy = ConvertType(E->getType()); 1885 1886 Expr *BaseExpr = E->getBase(); 1887 if (BaseExpr->isLvalue(getContext()) != Expr::LV_Valid) { 1888 V = CreateTempAlloca(ClassPtrTy, "resval"); 1889 llvm::Value *Src = EmitScalarExpr(BaseExpr); 1890 Builder.CreateStore(Src, V); 1891 LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType())); 1892 V = ScalarExprEmitter(*this).EmitLoadOfLValue(LV, E->getType()); 1893 } 1894 else { 1895 if (E->isArrow()) 1896 V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr); 1897 else 1898 V = EmitLValue(BaseExpr).getAddress(); 1899 } 1900 1901 // build Class* type 1902 ClassPtrTy = ClassPtrTy->getPointerTo(); 1903 V = Builder.CreateBitCast(V, ClassPtrTy); 1904 LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType())); 1905 return LV; 1906} 1907 1908