CGExprScalar.cpp revision 206084
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 (CE->getCastKind() == CastExpr::CK_UncheckedDerivedToBase) 774 return false; 775 776 if (isa<CXXThisExpr>(E)) { 777 // We always assume that 'this' is never null. 778 return false; 779 } 780 781 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { 782 // And that lvalue casts are never null. 783 if (ICE->isLvalueCast()) 784 return false; 785 } 786 787 return true; 788} 789 790// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 791// have to handle a more broad range of conversions than explicit casts, as they 792// handle things like function to ptr-to-function decay etc. 793Value *ScalarExprEmitter::EmitCastExpr(CastExpr *CE) { 794 Expr *E = CE->getSubExpr(); 795 QualType DestTy = CE->getType(); 796 CastExpr::CastKind Kind = CE->getCastKind(); 797 798 if (!DestTy->isVoidType()) 799 TestAndClearIgnoreResultAssign(); 800 801 // Since almost all cast kinds apply to scalars, this switch doesn't have 802 // a default case, so the compiler will warn on a missing case. The cases 803 // are in the same order as in the CastKind enum. 804 switch (Kind) { 805 case CastExpr::CK_Unknown: 806 // FIXME: All casts should have a known kind! 807 //assert(0 && "Unknown cast kind!"); 808 break; 809 810 case CastExpr::CK_AnyPointerToObjCPointerCast: 811 case CastExpr::CK_AnyPointerToBlockPointerCast: 812 case CastExpr::CK_BitCast: { 813 Value *Src = Visit(const_cast<Expr*>(E)); 814 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 815 } 816 case CastExpr::CK_NoOp: 817 case CastExpr::CK_UserDefinedConversion: 818 return Visit(const_cast<Expr*>(E)); 819 820 case CastExpr::CK_BaseToDerived: { 821 const CXXRecordDecl *BaseClassDecl = 822 E->getType()->getCXXRecordDeclForPointerType(); 823 const CXXRecordDecl *DerivedClassDecl = 824 DestTy->getCXXRecordDeclForPointerType(); 825 826 Value *Src = Visit(const_cast<Expr*>(E)); 827 828 bool NullCheckValue = ShouldNullCheckClassCastValue(CE); 829 return CGF.GetAddressOfDerivedClass(Src, BaseClassDecl, DerivedClassDecl, 830 NullCheckValue); 831 } 832 case CastExpr::CK_UncheckedDerivedToBase: 833 case CastExpr::CK_DerivedToBase: { 834 const RecordType *DerivedClassTy = 835 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 836 CXXRecordDecl *DerivedClassDecl = 837 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 838 839 const RecordType *BaseClassTy = 840 DestTy->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 841 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseClassTy->getDecl()); 842 843 Value *Src = Visit(const_cast<Expr*>(E)); 844 845 bool NullCheckValue = ShouldNullCheckClassCastValue(CE); 846 return CGF.GetAddressOfBaseClass(Src, DerivedClassDecl, BaseClassDecl, 847 NullCheckValue); 848 } 849 case CastExpr::CK_Dynamic: { 850 Value *V = Visit(const_cast<Expr*>(E)); 851 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 852 return CGF.EmitDynamicCast(V, DCE); 853 } 854 case CastExpr::CK_ToUnion: 855 assert(0 && "Should be unreachable!"); 856 break; 857 858 case CastExpr::CK_ArrayToPointerDecay: { 859 assert(E->getType()->isArrayType() && 860 "Array to pointer decay must have array source type!"); 861 862 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 863 864 // Note that VLA pointers are always decayed, so we don't need to do 865 // anything here. 866 if (!E->getType()->isVariableArrayType()) { 867 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 868 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 869 ->getElementType()) && 870 "Expected pointer to array"); 871 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 872 } 873 874 return V; 875 } 876 case CastExpr::CK_FunctionToPointerDecay: 877 return EmitLValue(E).getAddress(); 878 879 case CastExpr::CK_NullToMemberPointer: 880 return CGF.CGM.EmitNullConstant(DestTy); 881 882 case CastExpr::CK_BaseToDerivedMemberPointer: 883 case CastExpr::CK_DerivedToBaseMemberPointer: { 884 Value *Src = Visit(E); 885 886 // See if we need to adjust the pointer. 887 const CXXRecordDecl *BaseDecl = 888 cast<CXXRecordDecl>(E->getType()->getAs<MemberPointerType>()-> 889 getClass()->getAs<RecordType>()->getDecl()); 890 const CXXRecordDecl *DerivedDecl = 891 cast<CXXRecordDecl>(CE->getType()->getAs<MemberPointerType>()-> 892 getClass()->getAs<RecordType>()->getDecl()); 893 if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) 894 std::swap(DerivedDecl, BaseDecl); 895 896 if (llvm::Constant *Adj = 897 CGF.CGM.GetNonVirtualBaseClassOffset(DerivedDecl, BaseDecl)) { 898 if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) 899 Src = Builder.CreateSub(Src, Adj, "adj"); 900 else 901 Src = Builder.CreateAdd(Src, Adj, "adj"); 902 } 903 return Src; 904 } 905 906 case CastExpr::CK_ConstructorConversion: 907 assert(0 && "Should be unreachable!"); 908 break; 909 910 case CastExpr::CK_IntegralToPointer: { 911 Value *Src = Visit(const_cast<Expr*>(E)); 912 913 // First, convert to the correct width so that we control the kind of 914 // extension. 915 const llvm::Type *MiddleTy = 916 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 917 bool InputSigned = E->getType()->isSignedIntegerType(); 918 llvm::Value* IntResult = 919 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 920 921 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 922 } 923 case CastExpr::CK_PointerToIntegral: { 924 Value *Src = Visit(const_cast<Expr*>(E)); 925 return Builder.CreatePtrToInt(Src, ConvertType(DestTy)); 926 } 927 case CastExpr::CK_ToVoid: { 928 CGF.EmitAnyExpr(E, 0, false, true); 929 return 0; 930 } 931 case CastExpr::CK_VectorSplat: { 932 const llvm::Type *DstTy = ConvertType(DestTy); 933 Value *Elt = Visit(const_cast<Expr*>(E)); 934 935 // Insert the element in element zero of an undef vector 936 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 937 llvm::Value *Idx = 938 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0); 939 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 940 941 // Splat the element across to all elements 942 llvm::SmallVector<llvm::Constant*, 16> Args; 943 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 944 for (unsigned i = 0; i < NumElements; i++) 945 Args.push_back(llvm::ConstantInt::get( 946 llvm::Type::getInt32Ty(VMContext), 0)); 947 948 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 949 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 950 return Yay; 951 } 952 case CastExpr::CK_IntegralCast: 953 case CastExpr::CK_IntegralToFloating: 954 case CastExpr::CK_FloatingToIntegral: 955 case CastExpr::CK_FloatingCast: 956 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 957 958 case CastExpr::CK_MemberPointerToBoolean: 959 return CGF.EvaluateExprAsBool(E); 960 } 961 962 // Handle cases where the source is an non-complex type. 963 964 if (!CGF.hasAggregateLLVMType(E->getType())) { 965 Value *Src = Visit(const_cast<Expr*>(E)); 966 967 // Use EmitScalarConversion to perform the conversion. 968 return EmitScalarConversion(Src, E->getType(), DestTy); 969 } 970 971 if (E->getType()->isAnyComplexType()) { 972 // Handle cases where the source is a complex type. 973 bool IgnoreImag = true; 974 bool IgnoreImagAssign = true; 975 bool IgnoreReal = IgnoreResultAssign; 976 bool IgnoreRealAssign = IgnoreResultAssign; 977 if (DestTy->isBooleanType()) 978 IgnoreImagAssign = IgnoreImag = false; 979 else if (DestTy->isVoidType()) { 980 IgnoreReal = IgnoreImag = false; 981 IgnoreRealAssign = IgnoreImagAssign = true; 982 } 983 CodeGenFunction::ComplexPairTy V 984 = CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign, 985 IgnoreImagAssign); 986 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 987 } 988 989 // Okay, this is a cast from an aggregate. It must be a cast to void. Just 990 // evaluate the result and return. 991 CGF.EmitAggExpr(E, 0, false, true); 992 return 0; 993} 994 995Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 996 return CGF.EmitCompoundStmt(*E->getSubStmt(), 997 !E->getType()->isVoidType()).getScalarVal(); 998} 999 1000Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 1001 llvm::Value *V = CGF.GetAddrOfBlockDecl(E); 1002 if (E->getType().isObjCGCWeak()) 1003 return CGF.CGM.getObjCRuntime().EmitObjCWeakRead(CGF, V); 1004 return Builder.CreateLoad(V, "tmp"); 1005} 1006 1007//===----------------------------------------------------------------------===// 1008// Unary Operators 1009//===----------------------------------------------------------------------===// 1010 1011Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1012 TestAndClearIgnoreResultAssign(); 1013 Value *Op = Visit(E->getSubExpr()); 1014 if (Op->getType()->isFPOrFPVectorTy()) 1015 return Builder.CreateFNeg(Op, "neg"); 1016 return Builder.CreateNeg(Op, "neg"); 1017} 1018 1019Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1020 TestAndClearIgnoreResultAssign(); 1021 Value *Op = Visit(E->getSubExpr()); 1022 return Builder.CreateNot(Op, "neg"); 1023} 1024 1025Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1026 // Compare operand to zero. 1027 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1028 1029 // Invert value. 1030 // TODO: Could dynamically modify easy computations here. For example, if 1031 // the operand is an icmp ne, turn into icmp eq. 1032 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1033 1034 // ZExt result to the expr type. 1035 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1036} 1037 1038/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of 1039/// argument of the sizeof expression as an integer. 1040Value * 1041ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { 1042 QualType TypeToSize = E->getTypeOfArgument(); 1043 if (E->isSizeOf()) { 1044 if (const VariableArrayType *VAT = 1045 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1046 if (E->isArgumentType()) { 1047 // sizeof(type) - make sure to emit the VLA size. 1048 CGF.EmitVLASize(TypeToSize); 1049 } else { 1050 // C99 6.5.3.4p2: If the argument is an expression of type 1051 // VLA, it is evaluated. 1052 CGF.EmitAnyExpr(E->getArgumentExpr()); 1053 } 1054 1055 return CGF.GetVLASize(VAT); 1056 } 1057 } 1058 1059 // If this isn't sizeof(vla), the result must be constant; use the constant 1060 // folding logic so we don't have to duplicate it here. 1061 Expr::EvalResult Result; 1062 E->Evaluate(Result, CGF.getContext()); 1063 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 1064} 1065 1066Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1067 Expr *Op = E->getSubExpr(); 1068 if (Op->getType()->isAnyComplexType()) 1069 return CGF.EmitComplexExpr(Op, false, true, false, true).first; 1070 return Visit(Op); 1071} 1072Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1073 Expr *Op = E->getSubExpr(); 1074 if (Op->getType()->isAnyComplexType()) 1075 return CGF.EmitComplexExpr(Op, true, false, true, false).second; 1076 1077 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1078 // effects are evaluated, but not the actual value. 1079 if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) 1080 CGF.EmitLValue(Op); 1081 else 1082 CGF.EmitScalarExpr(Op, true); 1083 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1084} 1085 1086Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) { 1087 Value* ResultAsPtr = EmitLValue(E->getSubExpr()).getAddress(); 1088 const llvm::Type* ResultType = ConvertType(E->getType()); 1089 return Builder.CreatePtrToInt(ResultAsPtr, ResultType, "offsetof"); 1090} 1091 1092//===----------------------------------------------------------------------===// 1093// Binary Operators 1094//===----------------------------------------------------------------------===// 1095 1096BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1097 TestAndClearIgnoreResultAssign(); 1098 BinOpInfo Result; 1099 Result.LHS = Visit(E->getLHS()); 1100 Result.RHS = Visit(E->getRHS()); 1101 Result.Ty = E->getType(); 1102 Result.E = E; 1103 return Result; 1104} 1105 1106Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 1107 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 1108 bool Ignore = TestAndClearIgnoreResultAssign(); 1109 QualType LHSTy = E->getLHS()->getType(); 1110 1111 BinOpInfo OpInfo; 1112 1113 if (E->getComputationResultType()->isAnyComplexType()) { 1114 // This needs to go through the complex expression emitter, but it's a tad 1115 // complicated to do that... I'm leaving it out for now. (Note that we do 1116 // actually need the imaginary part of the RHS for multiplication and 1117 // division.) 1118 CGF.ErrorUnsupported(E, "complex compound assignment"); 1119 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 1120 } 1121 1122 // Emit the RHS first. __block variables need to have the rhs evaluated 1123 // first, plus this should improve codegen a little. 1124 OpInfo.RHS = Visit(E->getRHS()); 1125 OpInfo.Ty = E->getComputationResultType(); 1126 OpInfo.E = E; 1127 // Load/convert the LHS. 1128 LValue LHSLV = EmitCheckedLValue(E->getLHS()); 1129 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 1130 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 1131 E->getComputationLHSType()); 1132 1133 // Expand the binary operator. 1134 Value *Result = (this->*Func)(OpInfo); 1135 1136 // Convert the result back to the LHS type. 1137 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 1138 1139 // Store the result value into the LHS lvalue. Bit-fields are handled 1140 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 1141 // 'An assignment expression has the value of the left operand after the 1142 // assignment...'. 1143 if (LHSLV.isBitfield()) { 1144 if (!LHSLV.isVolatileQualified()) { 1145 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, 1146 &Result); 1147 return Result; 1148 } else 1149 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy); 1150 } else 1151 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); 1152 if (Ignore) 1153 return 0; 1154 return EmitLoadOfLValue(LHSLV, E->getType()); 1155} 1156 1157 1158Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 1159 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1160 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 1161 else if (Ops.Ty->isUnsignedIntegerType()) 1162 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 1163 else 1164 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 1165} 1166 1167Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 1168 // Rem in C can't be a floating point type: C99 6.5.5p2. 1169 if (Ops.Ty->isUnsignedIntegerType()) 1170 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 1171 else 1172 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 1173} 1174 1175Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 1176 unsigned IID; 1177 unsigned OpID = 0; 1178 1179 switch (Ops.E->getOpcode()) { 1180 case BinaryOperator::Add: 1181 case BinaryOperator::AddAssign: 1182 OpID = 1; 1183 IID = llvm::Intrinsic::sadd_with_overflow; 1184 break; 1185 case BinaryOperator::Sub: 1186 case BinaryOperator::SubAssign: 1187 OpID = 2; 1188 IID = llvm::Intrinsic::ssub_with_overflow; 1189 break; 1190 case BinaryOperator::Mul: 1191 case BinaryOperator::MulAssign: 1192 OpID = 3; 1193 IID = llvm::Intrinsic::smul_with_overflow; 1194 break; 1195 default: 1196 assert(false && "Unsupported operation for overflow detection"); 1197 IID = 0; 1198 } 1199 OpID <<= 1; 1200 OpID |= 1; 1201 1202 const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1203 1204 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1); 1205 1206 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1207 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1208 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1209 1210 // Branch in case of overflow. 1211 llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); 1212 llvm::BasicBlock *overflowBB = 1213 CGF.createBasicBlock("overflow", CGF.CurFn); 1214 llvm::BasicBlock *continueBB = 1215 CGF.createBasicBlock("overflow.continue", CGF.CurFn); 1216 1217 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1218 1219 // Handle overflow 1220 1221 Builder.SetInsertPoint(overflowBB); 1222 1223 // Handler is: 1224 // long long *__overflow_handler)(long long a, long long b, char op, 1225 // char width) 1226 std::vector<const llvm::Type*> handerArgTypes; 1227 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1228 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1229 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1230 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1231 llvm::FunctionType *handlerTy = llvm::FunctionType::get( 1232 llvm::Type::getInt64Ty(VMContext), handerArgTypes, false); 1233 llvm::Value *handlerFunction = 1234 CGF.CGM.getModule().getOrInsertGlobal("__overflow_handler", 1235 llvm::PointerType::getUnqual(handlerTy)); 1236 handlerFunction = Builder.CreateLoad(handlerFunction); 1237 1238 llvm::Value *handlerResult = Builder.CreateCall4(handlerFunction, 1239 Builder.CreateSExt(Ops.LHS, llvm::Type::getInt64Ty(VMContext)), 1240 Builder.CreateSExt(Ops.RHS, llvm::Type::getInt64Ty(VMContext)), 1241 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), OpID), 1242 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), 1243 cast<llvm::IntegerType>(opTy)->getBitWidth())); 1244 1245 handlerResult = Builder.CreateTrunc(handlerResult, opTy); 1246 1247 Builder.CreateBr(continueBB); 1248 1249 // Set up the continuation 1250 Builder.SetInsertPoint(continueBB); 1251 // Get the correct result 1252 llvm::PHINode *phi = Builder.CreatePHI(opTy); 1253 phi->reserveOperandSpace(2); 1254 phi->addIncoming(result, initialBB); 1255 phi->addIncoming(handlerResult, overflowBB); 1256 1257 return phi; 1258} 1259 1260Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 1261 if (!Ops.Ty->isAnyPointerType()) { 1262 if (CGF.getContext().getLangOptions().OverflowChecking && 1263 Ops.Ty->isSignedIntegerType()) 1264 return EmitOverflowCheckedBinOp(Ops); 1265 1266 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1267 return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add"); 1268 1269 // Signed integer overflow is undefined behavior. 1270 if (Ops.Ty->isSignedIntegerType()) 1271 return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add"); 1272 1273 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1274 } 1275 1276 if (Ops.Ty->isPointerType() && 1277 Ops.Ty->getAs<PointerType>()->isVariableArrayType()) { 1278 // The amount of the addition needs to account for the VLA size 1279 CGF.ErrorUnsupported(Ops.E, "VLA pointer addition"); 1280 } 1281 Value *Ptr, *Idx; 1282 Expr *IdxExp; 1283 const PointerType *PT = Ops.E->getLHS()->getType()->getAs<PointerType>(); 1284 const ObjCObjectPointerType *OPT = 1285 Ops.E->getLHS()->getType()->getAs<ObjCObjectPointerType>(); 1286 if (PT || OPT) { 1287 Ptr = Ops.LHS; 1288 Idx = Ops.RHS; 1289 IdxExp = Ops.E->getRHS(); 1290 } else { // int + pointer 1291 PT = Ops.E->getRHS()->getType()->getAs<PointerType>(); 1292 OPT = Ops.E->getRHS()->getType()->getAs<ObjCObjectPointerType>(); 1293 assert((PT || OPT) && "Invalid add expr"); 1294 Ptr = Ops.RHS; 1295 Idx = Ops.LHS; 1296 IdxExp = Ops.E->getLHS(); 1297 } 1298 1299 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1300 if (Width < CGF.LLVMPointerWidth) { 1301 // Zero or sign extend the pointer value based on whether the index is 1302 // signed or not. 1303 const llvm::Type *IdxType = 1304 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1305 if (IdxExp->getType()->isSignedIntegerType()) 1306 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1307 else 1308 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1309 } 1310 const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType(); 1311 // Handle interface types, which are not represented with a concrete type. 1312 if (const ObjCInterfaceType *OIT = dyn_cast<ObjCInterfaceType>(ElementType)) { 1313 llvm::Value *InterfaceSize = 1314 llvm::ConstantInt::get(Idx->getType(), 1315 CGF.getContext().getTypeSizeInChars(OIT).getQuantity()); 1316 Idx = Builder.CreateMul(Idx, InterfaceSize); 1317 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1318 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1319 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1320 return Builder.CreateBitCast(Res, Ptr->getType()); 1321 } 1322 1323 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 1324 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 1325 // future proof. 1326 if (ElementType->isVoidType() || ElementType->isFunctionType()) { 1327 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1328 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1329 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1330 return Builder.CreateBitCast(Res, Ptr->getType()); 1331 } 1332 1333 return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr"); 1334} 1335 1336Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 1337 if (!isa<llvm::PointerType>(Ops.LHS->getType())) { 1338 if (CGF.getContext().getLangOptions().OverflowChecking 1339 && Ops.Ty->isSignedIntegerType()) 1340 return EmitOverflowCheckedBinOp(Ops); 1341 1342 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1343 return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub"); 1344 1345 // Signed integer overflow is undefined behavior. 1346 if (Ops.Ty->isSignedIntegerType()) 1347 return Builder.CreateNSWSub(Ops.LHS, Ops.RHS, "sub"); 1348 1349 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1350 } 1351 1352 if (Ops.E->getLHS()->getType()->isPointerType() && 1353 Ops.E->getLHS()->getType()->getAs<PointerType>()->isVariableArrayType()) { 1354 // The amount of the addition needs to account for the VLA size for 1355 // ptr-int 1356 // The amount of the division needs to account for the VLA size for 1357 // ptr-ptr. 1358 CGF.ErrorUnsupported(Ops.E, "VLA pointer subtraction"); 1359 } 1360 1361 const QualType LHSType = Ops.E->getLHS()->getType(); 1362 const QualType LHSElementType = LHSType->getPointeeType(); 1363 if (!isa<llvm::PointerType>(Ops.RHS->getType())) { 1364 // pointer - int 1365 Value *Idx = Ops.RHS; 1366 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1367 if (Width < CGF.LLVMPointerWidth) { 1368 // Zero or sign extend the pointer value based on whether the index is 1369 // signed or not. 1370 const llvm::Type *IdxType = 1371 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1372 if (Ops.E->getRHS()->getType()->isSignedIntegerType()) 1373 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1374 else 1375 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1376 } 1377 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); 1378 1379 // Handle interface types, which are not represented with a concrete type. 1380 if (const ObjCInterfaceType *OIT = 1381 dyn_cast<ObjCInterfaceType>(LHSElementType)) { 1382 llvm::Value *InterfaceSize = 1383 llvm::ConstantInt::get(Idx->getType(), 1384 CGF.getContext(). 1385 getTypeSizeInChars(OIT).getQuantity()); 1386 Idx = Builder.CreateMul(Idx, InterfaceSize); 1387 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1388 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1389 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr"); 1390 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1391 } 1392 1393 // Explicitly handle GNU void* and function pointer arithmetic 1394 // extensions. The GNU void* casts amount to no-ops since our void* type is 1395 // i8*, but this is future proof. 1396 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1397 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1398 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1399 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); 1400 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1401 } 1402 1403 return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr"); 1404 } else { 1405 // pointer - pointer 1406 Value *LHS = Ops.LHS; 1407 Value *RHS = Ops.RHS; 1408 1409 CharUnits ElementSize; 1410 1411 // Handle GCC extension for pointer arithmetic on void* and function pointer 1412 // types. 1413 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1414 ElementSize = CharUnits::One(); 1415 } else { 1416 ElementSize = CGF.getContext().getTypeSizeInChars(LHSElementType); 1417 } 1418 1419 const llvm::Type *ResultType = ConvertType(Ops.Ty); 1420 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 1421 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 1422 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 1423 1424 // Optimize out the shift for element size of 1. 1425 if (ElementSize.isOne()) 1426 return BytesBetween; 1427 1428 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 1429 // pointer difference in C is only defined in the case where both operands 1430 // are pointing to elements of an array. 1431 Value *BytesPerElt = 1432 llvm::ConstantInt::get(ResultType, ElementSize.getQuantity()); 1433 return Builder.CreateExactSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 1434 } 1435} 1436 1437Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 1438 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1439 // RHS to the same size as the LHS. 1440 Value *RHS = Ops.RHS; 1441 if (Ops.LHS->getType() != RHS->getType()) 1442 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1443 1444 if (CGF.CatchUndefined 1445 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1446 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1447 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1448 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1449 llvm::ConstantInt::get(RHS->getType(), Width)), 1450 Cont, CGF.getTrapBB()); 1451 CGF.EmitBlock(Cont); 1452 } 1453 1454 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 1455} 1456 1457Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 1458 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1459 // RHS to the same size as the LHS. 1460 Value *RHS = Ops.RHS; 1461 if (Ops.LHS->getType() != RHS->getType()) 1462 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1463 1464 if (CGF.CatchUndefined 1465 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1466 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1467 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1468 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1469 llvm::ConstantInt::get(RHS->getType(), Width)), 1470 Cont, CGF.getTrapBB()); 1471 CGF.EmitBlock(Cont); 1472 } 1473 1474 if (Ops.Ty->isUnsignedIntegerType()) 1475 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 1476 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 1477} 1478 1479Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 1480 unsigned SICmpOpc, unsigned FCmpOpc) { 1481 TestAndClearIgnoreResultAssign(); 1482 Value *Result; 1483 QualType LHSTy = E->getLHS()->getType(); 1484 if (LHSTy->isMemberFunctionPointerType()) { 1485 Value *LHSPtr = CGF.EmitAnyExprToTemp(E->getLHS()).getAggregateAddr(); 1486 Value *RHSPtr = CGF.EmitAnyExprToTemp(E->getRHS()).getAggregateAddr(); 1487 llvm::Value *LHSFunc = Builder.CreateStructGEP(LHSPtr, 0); 1488 LHSFunc = Builder.CreateLoad(LHSFunc); 1489 llvm::Value *RHSFunc = Builder.CreateStructGEP(RHSPtr, 0); 1490 RHSFunc = Builder.CreateLoad(RHSFunc); 1491 Value *ResultF = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1492 LHSFunc, RHSFunc, "cmp.func"); 1493 Value *NullPtr = llvm::Constant::getNullValue(LHSFunc->getType()); 1494 Value *ResultNull = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1495 LHSFunc, NullPtr, "cmp.null"); 1496 llvm::Value *LHSAdj = Builder.CreateStructGEP(LHSPtr, 1); 1497 LHSAdj = Builder.CreateLoad(LHSAdj); 1498 llvm::Value *RHSAdj = Builder.CreateStructGEP(RHSPtr, 1); 1499 RHSAdj = Builder.CreateLoad(RHSAdj); 1500 Value *ResultA = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1501 LHSAdj, RHSAdj, "cmp.adj"); 1502 if (E->getOpcode() == BinaryOperator::EQ) { 1503 Result = Builder.CreateOr(ResultNull, ResultA, "or.na"); 1504 Result = Builder.CreateAnd(Result, ResultF, "and.f"); 1505 } else { 1506 assert(E->getOpcode() == BinaryOperator::NE && 1507 "Member pointer comparison other than == or != ?"); 1508 Result = Builder.CreateAnd(ResultNull, ResultA, "and.na"); 1509 Result = Builder.CreateOr(Result, ResultF, "or.f"); 1510 } 1511 } else if (!LHSTy->isAnyComplexType()) { 1512 Value *LHS = Visit(E->getLHS()); 1513 Value *RHS = Visit(E->getRHS()); 1514 1515 if (LHS->getType()->isFPOrFPVectorTy()) { 1516 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 1517 LHS, RHS, "cmp"); 1518 } else if (LHSTy->isSignedIntegerType()) { 1519 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 1520 LHS, RHS, "cmp"); 1521 } else { 1522 // Unsigned integers and pointers. 1523 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1524 LHS, RHS, "cmp"); 1525 } 1526 1527 // If this is a vector comparison, sign extend the result to the appropriate 1528 // vector integer type and return it (don't convert to bool). 1529 if (LHSTy->isVectorType()) 1530 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 1531 1532 } else { 1533 // Complex Comparison: can only be an equality comparison. 1534 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 1535 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 1536 1537 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 1538 1539 Value *ResultR, *ResultI; 1540 if (CETy->isRealFloatingType()) { 1541 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1542 LHS.first, RHS.first, "cmp.r"); 1543 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1544 LHS.second, RHS.second, "cmp.i"); 1545 } else { 1546 // Complex comparisons can only be equality comparisons. As such, signed 1547 // and unsigned opcodes are the same. 1548 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1549 LHS.first, RHS.first, "cmp.r"); 1550 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1551 LHS.second, RHS.second, "cmp.i"); 1552 } 1553 1554 if (E->getOpcode() == BinaryOperator::EQ) { 1555 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 1556 } else { 1557 assert(E->getOpcode() == BinaryOperator::NE && 1558 "Complex comparison other than == or != ?"); 1559 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 1560 } 1561 } 1562 1563 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 1564} 1565 1566Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 1567 bool Ignore = TestAndClearIgnoreResultAssign(); 1568 1569 // __block variables need to have the rhs evaluated first, plus this should 1570 // improve codegen just a little. 1571 Value *RHS = Visit(E->getRHS()); 1572 LValue LHS = EmitCheckedLValue(E->getLHS()); 1573 1574 // Store the value into the LHS. Bit-fields are handled specially 1575 // because the result is altered by the store, i.e., [C99 6.5.16p1] 1576 // 'An assignment expression has the value of the left operand after 1577 // the assignment...'. 1578 if (LHS.isBitfield()) { 1579 if (!LHS.isVolatileQualified()) { 1580 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), 1581 &RHS); 1582 return RHS; 1583 } else 1584 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType()); 1585 } else 1586 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 1587 if (Ignore) 1588 return 0; 1589 return EmitLoadOfLValue(LHS, E->getType()); 1590} 1591 1592Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 1593 const llvm::Type *ResTy = ConvertType(E->getType()); 1594 1595 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 1596 // If we have 1 && X, just emit X without inserting the control flow. 1597 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1598 if (Cond == 1) { // If we have 1 && X, just emit X. 1599 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1600 // ZExt result to int or bool. 1601 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 1602 } 1603 1604 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 1605 if (!CGF.ContainsLabel(E->getRHS())) 1606 return llvm::Constant::getNullValue(ResTy); 1607 } 1608 1609 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 1610 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 1611 1612 // Branch on the LHS first. If it is false, go to the failure (cont) block. 1613 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 1614 1615 // Any edges into the ContBlock are now from an (indeterminate number of) 1616 // edges from this first condition. All of these values will be false. Start 1617 // setting up the PHI node in the Cont Block for this. 1618 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1619 "", ContBlock); 1620 PN->reserveOperandSpace(2); // Normal case, two inputs. 1621 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1622 PI != PE; ++PI) 1623 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 1624 1625 CGF.BeginConditionalBranch(); 1626 CGF.EmitBlock(RHSBlock); 1627 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1628 CGF.EndConditionalBranch(); 1629 1630 // Reaquire the RHS block, as there may be subblocks inserted. 1631 RHSBlock = Builder.GetInsertBlock(); 1632 1633 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1634 // into the phi node for the edge with the value of RHSCond. 1635 CGF.EmitBlock(ContBlock); 1636 PN->addIncoming(RHSCond, RHSBlock); 1637 1638 // ZExt result to int. 1639 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); 1640} 1641 1642Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 1643 const llvm::Type *ResTy = ConvertType(E->getType()); 1644 1645 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 1646 // If we have 0 || X, just emit X without inserting the control flow. 1647 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1648 if (Cond == -1) { // If we have 0 || X, just emit X. 1649 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1650 // ZExt result to int or bool. 1651 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 1652 } 1653 1654 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 1655 if (!CGF.ContainsLabel(E->getRHS())) 1656 return llvm::ConstantInt::get(ResTy, 1); 1657 } 1658 1659 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 1660 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 1661 1662 // Branch on the LHS first. If it is true, go to the success (cont) block. 1663 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 1664 1665 // Any edges into the ContBlock are now from an (indeterminate number of) 1666 // edges from this first condition. All of these values will be true. Start 1667 // setting up the PHI node in the Cont Block for this. 1668 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1669 "", ContBlock); 1670 PN->reserveOperandSpace(2); // Normal case, two inputs. 1671 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1672 PI != PE; ++PI) 1673 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 1674 1675 CGF.BeginConditionalBranch(); 1676 1677 // Emit the RHS condition as a bool value. 1678 CGF.EmitBlock(RHSBlock); 1679 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1680 1681 CGF.EndConditionalBranch(); 1682 1683 // Reaquire the RHS block, as there may be subblocks inserted. 1684 RHSBlock = Builder.GetInsertBlock(); 1685 1686 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1687 // into the phi node for the edge with the value of RHSCond. 1688 CGF.EmitBlock(ContBlock); 1689 PN->addIncoming(RHSCond, RHSBlock); 1690 1691 // ZExt result to int. 1692 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 1693} 1694 1695Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 1696 CGF.EmitStmt(E->getLHS()); 1697 CGF.EnsureInsertPoint(); 1698 return Visit(E->getRHS()); 1699} 1700 1701//===----------------------------------------------------------------------===// 1702// Other Operators 1703//===----------------------------------------------------------------------===// 1704 1705/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 1706/// expression is cheap enough and side-effect-free enough to evaluate 1707/// unconditionally instead of conditionally. This is used to convert control 1708/// flow into selects in some cases. 1709static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 1710 CodeGenFunction &CGF) { 1711 if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) 1712 return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr(), CGF); 1713 1714 // TODO: Allow anything we can constant fold to an integer or fp constant. 1715 if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || 1716 isa<FloatingLiteral>(E)) 1717 return true; 1718 1719 // Non-volatile automatic variables too, to get "cond ? X : Y" where 1720 // X and Y are local variables. 1721 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 1722 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 1723 if (VD->hasLocalStorage() && !(CGF.getContext() 1724 .getCanonicalType(VD->getType()) 1725 .isVolatileQualified())) 1726 return true; 1727 1728 return false; 1729} 1730 1731 1732Value *ScalarExprEmitter:: 1733VisitConditionalOperator(const ConditionalOperator *E) { 1734 TestAndClearIgnoreResultAssign(); 1735 // If the condition constant folds and can be elided, try to avoid emitting 1736 // the condition and the dead arm. 1737 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ 1738 Expr *Live = E->getLHS(), *Dead = E->getRHS(); 1739 if (Cond == -1) 1740 std::swap(Live, Dead); 1741 1742 // If the dead side doesn't have labels we need, and if the Live side isn't 1743 // the gnu missing ?: extension (which we could handle, but don't bother 1744 // to), just emit the Live part. 1745 if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part 1746 Live) // Live part isn't missing. 1747 return Visit(Live); 1748 } 1749 1750 1751 // If this is a really simple expression (like x ? 4 : 5), emit this as a 1752 // select instead of as control flow. We can only do this if it is cheap and 1753 // safe to evaluate the LHS and RHS unconditionally. 1754 if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS(), 1755 CGF) && 1756 isCheapEnoughToEvaluateUnconditionally(E->getRHS(), CGF)) { 1757 llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); 1758 llvm::Value *LHS = Visit(E->getLHS()); 1759 llvm::Value *RHS = Visit(E->getRHS()); 1760 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 1761 } 1762 1763 1764 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 1765 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 1766 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 1767 Value *CondVal = 0; 1768 1769 // If we don't have the GNU missing condition extension, emit a branch on bool 1770 // the normal way. 1771 if (E->getLHS()) { 1772 // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for 1773 // the branch on bool. 1774 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); 1775 } else { 1776 // Otherwise, for the ?: extension, evaluate the conditional and then 1777 // convert it to bool the hard way. We do this explicitly because we need 1778 // the unconverted value for the missing middle value of the ?:. 1779 CondVal = CGF.EmitScalarExpr(E->getCond()); 1780 1781 // In some cases, EmitScalarConversion will delete the "CondVal" expression 1782 // if there are no extra uses (an optimization). Inhibit this by making an 1783 // extra dead use, because we're going to add a use of CondVal later. We 1784 // don't use the builder for this, because we don't want it to get optimized 1785 // away. This leaves dead code, but the ?: extension isn't common. 1786 new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", 1787 Builder.GetInsertBlock()); 1788 1789 Value *CondBoolVal = 1790 CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 1791 CGF.getContext().BoolTy); 1792 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 1793 } 1794 1795 CGF.BeginConditionalBranch(); 1796 CGF.EmitBlock(LHSBlock); 1797 1798 // Handle the GNU extension for missing LHS. 1799 Value *LHS; 1800 if (E->getLHS()) 1801 LHS = Visit(E->getLHS()); 1802 else // Perform promotions, to handle cases like "short ?: int" 1803 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); 1804 1805 CGF.EndConditionalBranch(); 1806 LHSBlock = Builder.GetInsertBlock(); 1807 CGF.EmitBranch(ContBlock); 1808 1809 CGF.BeginConditionalBranch(); 1810 CGF.EmitBlock(RHSBlock); 1811 1812 Value *RHS = Visit(E->getRHS()); 1813 CGF.EndConditionalBranch(); 1814 RHSBlock = Builder.GetInsertBlock(); 1815 CGF.EmitBranch(ContBlock); 1816 1817 CGF.EmitBlock(ContBlock); 1818 1819 // If the LHS or RHS is a throw expression, it will be legitimately null. 1820 if (!LHS) 1821 return RHS; 1822 if (!RHS) 1823 return LHS; 1824 1825 // Create a PHI node for the real part. 1826 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 1827 PN->reserveOperandSpace(2); 1828 PN->addIncoming(LHS, LHSBlock); 1829 PN->addIncoming(RHS, RHSBlock); 1830 return PN; 1831} 1832 1833Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 1834 return Visit(E->getChosenSubExpr(CGF.getContext())); 1835} 1836 1837Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 1838 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 1839 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 1840 1841 // If EmitVAArg fails, we fall back to the LLVM instruction. 1842 if (!ArgPtr) 1843 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 1844 1845 // FIXME Volatility. 1846 return Builder.CreateLoad(ArgPtr); 1847} 1848 1849Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { 1850 return CGF.BuildBlockLiteralTmp(BE); 1851} 1852 1853//===----------------------------------------------------------------------===// 1854// Entry Point into this File 1855//===----------------------------------------------------------------------===// 1856 1857/// EmitScalarExpr - Emit the computation of the specified expression of scalar 1858/// type, ignoring the result. 1859Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 1860 assert(E && !hasAggregateLLVMType(E->getType()) && 1861 "Invalid scalar expression to emit"); 1862 1863 return ScalarExprEmitter(*this, IgnoreResultAssign) 1864 .Visit(const_cast<Expr*>(E)); 1865} 1866 1867/// EmitScalarConversion - Emit a conversion from the specified type to the 1868/// specified destination type, both of which are LLVM scalar types. 1869Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 1870 QualType DstTy) { 1871 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 1872 "Invalid scalar expression to emit"); 1873 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 1874} 1875 1876/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 1877/// type to the specified destination type, where the destination type is an 1878/// LLVM scalar type. 1879Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 1880 QualType SrcTy, 1881 QualType DstTy) { 1882 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 1883 "Invalid complex -> scalar conversion"); 1884 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 1885 DstTy); 1886} 1887 1888LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) { 1889 llvm::Value *V; 1890 // object->isa or (*object).isa 1891 // Generate code as for: *(Class*)object 1892 // build Class* type 1893 const llvm::Type *ClassPtrTy = ConvertType(E->getType()); 1894 1895 Expr *BaseExpr = E->getBase(); 1896 if (BaseExpr->isLvalue(getContext()) != Expr::LV_Valid) { 1897 V = CreateTempAlloca(ClassPtrTy, "resval"); 1898 llvm::Value *Src = EmitScalarExpr(BaseExpr); 1899 Builder.CreateStore(Src, V); 1900 LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType())); 1901 V = ScalarExprEmitter(*this).EmitLoadOfLValue(LV, E->getType()); 1902 } 1903 else { 1904 if (E->isArrow()) 1905 V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr); 1906 else 1907 V = EmitLValue(BaseExpr).getAddress(); 1908 } 1909 1910 // build Class* type 1911 ClassPtrTy = ClassPtrTy->getPointerTo(); 1912 V = Builder.CreateBitCast(V, ClassPtrTy); 1913 LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType())); 1914 return LV; 1915} 1916 1917