CGExprScalar.cpp revision 8c3e7e7ddafe26f236741fb25e2898be4f3230ea
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/Compiler.h" 28#include "llvm/Support/CFG.h" 29#include "llvm/Target/TargetData.h" 30#include <cstdarg> 31 32using namespace clang; 33using namespace CodeGen; 34using llvm::Value; 35 36//===----------------------------------------------------------------------===// 37// Scalar Expression Emitter 38//===----------------------------------------------------------------------===// 39 40struct BinOpInfo { 41 Value *LHS; 42 Value *RHS; 43 QualType Ty; // Computation Type. 44 const BinaryOperator *E; 45}; 46 47namespace { 48class VISIBILITY_HIDDEN ScalarExprEmitter 49 : public StmtVisitor<ScalarExprEmitter, Value*> { 50 CodeGenFunction &CGF; 51 CGBuilderTy &Builder; 52 bool IgnoreResultAssign; 53 llvm::LLVMContext &VMContext; 54public: 55 56 ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false) 57 : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira), 58 VMContext(cgf.getLLVMContext()) { 59 } 60 61 //===--------------------------------------------------------------------===// 62 // Utilities 63 //===--------------------------------------------------------------------===// 64 65 bool TestAndClearIgnoreResultAssign() { 66 bool I = IgnoreResultAssign; 67 IgnoreResultAssign = false; 68 return I; 69 } 70 71 const llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); } 72 LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(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(EmitLValue(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 *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 172 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 173 Value *VisitMemberExpr(MemberExpr *E); 174 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 175 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 176 return EmitLoadOfLValue(E); 177 } 178 Value *VisitStringLiteral(Expr *E) { return EmitLValue(E).getAddress(); } 179 Value *VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { 180 return EmitLValue(E).getAddress(); 181 } 182 183 Value *VisitPredefinedExpr(Expr *E) { return EmitLValue(E).getAddress(); } 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(const 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(const 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 Value *VisitUnaryPostDec(const UnaryOperator *E) { 213 return VisitPrePostIncDec(E, false, false); 214 } 215 Value *VisitUnaryPostInc(const UnaryOperator *E) { 216 return VisitPrePostIncDec(E, true, false); 217 } 218 Value *VisitUnaryPreDec(const UnaryOperator *E) { 219 return VisitPrePostIncDec(E, false, true); 220 } 221 Value *VisitUnaryPreInc(const UnaryOperator *E) { 222 return VisitPrePostIncDec(E, true, true); 223 } 224 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 225 return EmitLValue(E->getSubExpr()).getAddress(); 226 } 227 Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } 228 Value *VisitUnaryPlus(const UnaryOperator *E) { 229 // This differs from gcc, though, most likely due to a bug in gcc. 230 TestAndClearIgnoreResultAssign(); 231 return Visit(E->getSubExpr()); 232 } 233 Value *VisitUnaryMinus (const UnaryOperator *E); 234 Value *VisitUnaryNot (const UnaryOperator *E); 235 Value *VisitUnaryLNot (const UnaryOperator *E); 236 Value *VisitUnaryReal (const UnaryOperator *E); 237 Value *VisitUnaryImag (const UnaryOperator *E); 238 Value *VisitUnaryExtension(const UnaryOperator *E) { 239 return Visit(E->getSubExpr()); 240 } 241 Value *VisitUnaryOffsetOf(const UnaryOperator *E); 242 243 // C++ 244 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 245 return Visit(DAE->getExpr()); 246 } 247 Value *VisitCXXThisExpr(CXXThisExpr *TE) { 248 return CGF.LoadCXXThis(); 249 } 250 251 Value *VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) { 252 return CGF.EmitCXXExprWithTemporaries(E).getScalarVal(); 253 } 254 Value *VisitCXXNewExpr(const CXXNewExpr *E) { 255 return CGF.EmitCXXNewExpr(E); 256 } 257 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { 258 CGF.EmitCXXDeleteExpr(E); 259 return 0; 260 } 261 262 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { 263 // C++ [expr.pseudo]p1: 264 // The result shall only be used as the operand for the function call 265 // operator (), and the result of such a call has type void. The only 266 // effect is the evaluation of the postfix-expression before the dot or 267 // arrow. 268 CGF.EmitScalarExpr(E->getBase()); 269 return 0; 270 } 271 272 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { 273 return llvm::Constant::getNullValue(ConvertType(E->getType())); 274 } 275 276 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { 277 CGF.EmitCXXThrowExpr(E); 278 return 0; 279 } 280 281 // Binary Operators. 282 Value *EmitMul(const BinOpInfo &Ops) { 283 if (CGF.getContext().getLangOptions().OverflowChecking 284 && Ops.Ty->isSignedIntegerType()) 285 return EmitOverflowCheckedBinOp(Ops); 286 if (Ops.LHS->getType()->isFPOrFPVector()) 287 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 288 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 289 } 290 /// Create a binary op that checks for overflow. 291 /// Currently only supports +, - and *. 292 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 293 Value *EmitDiv(const BinOpInfo &Ops); 294 Value *EmitRem(const BinOpInfo &Ops); 295 Value *EmitAdd(const BinOpInfo &Ops); 296 Value *EmitSub(const BinOpInfo &Ops); 297 Value *EmitShl(const BinOpInfo &Ops); 298 Value *EmitShr(const BinOpInfo &Ops); 299 Value *EmitAnd(const BinOpInfo &Ops) { 300 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 301 } 302 Value *EmitXor(const BinOpInfo &Ops) { 303 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 304 } 305 Value *EmitOr (const BinOpInfo &Ops) { 306 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 307 } 308 309 BinOpInfo EmitBinOps(const BinaryOperator *E); 310 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 311 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 312 313 // Binary operators and binary compound assignment operators. 314#define HANDLEBINOP(OP) \ 315 Value *VisitBin ## OP(const BinaryOperator *E) { \ 316 return Emit ## OP(EmitBinOps(E)); \ 317 } \ 318 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 319 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 320 } 321 HANDLEBINOP(Mul); 322 HANDLEBINOP(Div); 323 HANDLEBINOP(Rem); 324 HANDLEBINOP(Add); 325 HANDLEBINOP(Sub); 326 HANDLEBINOP(Shl); 327 HANDLEBINOP(Shr); 328 HANDLEBINOP(And); 329 HANDLEBINOP(Xor); 330 HANDLEBINOP(Or); 331#undef HANDLEBINOP 332 333 // Comparisons. 334 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 335 unsigned SICmpOpc, unsigned FCmpOpc); 336#define VISITCOMP(CODE, UI, SI, FP) \ 337 Value *VisitBin##CODE(const BinaryOperator *E) { \ 338 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 339 llvm::FCmpInst::FP); } 340 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT); 341 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT); 342 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE); 343 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE); 344 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ); 345 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE); 346#undef VISITCOMP 347 348 Value *VisitBinAssign (const BinaryOperator *E); 349 350 Value *VisitBinLAnd (const BinaryOperator *E); 351 Value *VisitBinLOr (const BinaryOperator *E); 352 Value *VisitBinComma (const BinaryOperator *E); 353 354 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } 355 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); } 356 357 // Other Operators. 358 Value *VisitBlockExpr(const BlockExpr *BE); 359 Value *VisitConditionalOperator(const ConditionalOperator *CO); 360 Value *VisitChooseExpr(ChooseExpr *CE); 361 Value *VisitVAArgExpr(VAArgExpr *VE); 362 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 363 return CGF.EmitObjCStringLiteral(E); 364 } 365}; 366} // end anonymous namespace. 367 368//===----------------------------------------------------------------------===// 369// Utilities 370//===----------------------------------------------------------------------===// 371 372/// EmitConversionToBool - Convert the specified expression value to a 373/// boolean (i1) truth value. This is equivalent to "Val != 0". 374Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 375 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs"); 376 377 if (SrcType->isRealFloatingType()) { 378 // Compare against 0.0 for fp scalars. 379 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 380 return Builder.CreateFCmpUNE(Src, Zero, "tobool"); 381 } 382 383 if (SrcType->isMemberPointerType()) { 384 // FIXME: This is ABI specific. 385 386 // Compare against -1. 387 llvm::Value *NegativeOne = llvm::Constant::getAllOnesValue(Src->getType()); 388 return Builder.CreateICmpNE(Src, NegativeOne, "tobool"); 389 } 390 391 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 392 "Unknown scalar type to convert"); 393 394 // Because of the type rules of C, we often end up computing a logical value, 395 // then zero extending it to int, then wanting it as a logical value again. 396 // Optimize this common case. 397 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) { 398 if (ZI->getOperand(0)->getType() == 399 llvm::Type::getInt1Ty(CGF.getLLVMContext())) { 400 Value *Result = ZI->getOperand(0); 401 // If there aren't any more uses, zap the instruction to save space. 402 // Note that there can be more uses, for example if this 403 // is the result of an assignment. 404 if (ZI->use_empty()) 405 ZI->eraseFromParent(); 406 return Result; 407 } 408 } 409 410 // Compare against an integer or pointer null. 411 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 412 return Builder.CreateICmpNE(Src, Zero, "tobool"); 413} 414 415/// EmitScalarConversion - Emit a conversion from the specified type to the 416/// specified destination type, both of which are LLVM scalar types. 417Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 418 QualType DstType) { 419 SrcType = CGF.getContext().getCanonicalType(SrcType); 420 DstType = CGF.getContext().getCanonicalType(DstType); 421 if (SrcType == DstType) return Src; 422 423 if (DstType->isVoidType()) return 0; 424 425 llvm::LLVMContext &VMContext = CGF.getLLVMContext(); 426 427 // Handle conversions to bool first, they are special: comparisons against 0. 428 if (DstType->isBooleanType()) 429 return EmitConversionToBool(Src, SrcType); 430 431 const llvm::Type *DstTy = ConvertType(DstType); 432 433 // Ignore conversions like int -> uint. 434 if (Src->getType() == DstTy) 435 return Src; 436 437 // Handle pointer conversions next: pointers can only be converted to/from 438 // other pointers and integers. Check for pointer types in terms of LLVM, as 439 // some native types (like Obj-C id) may map to a pointer type. 440 if (isa<llvm::PointerType>(DstTy)) { 441 // The source value may be an integer, or a pointer. 442 if (isa<llvm::PointerType>(Src->getType())) 443 return Builder.CreateBitCast(Src, DstTy, "conv"); 444 445 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 446 // First, convert to the correct width so that we control the kind of 447 // extension. 448 const llvm::Type *MiddleTy = 449 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 450 bool InputSigned = SrcType->isSignedIntegerType(); 451 llvm::Value* IntResult = 452 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 453 // Then, cast to pointer. 454 return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); 455 } 456 457 if (isa<llvm::PointerType>(Src->getType())) { 458 // Must be an ptr to int cast. 459 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 460 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 461 } 462 463 // A scalar can be splatted to an extended vector of the same element type 464 if (DstType->isExtVectorType() && !SrcType->isVectorType()) { 465 // Cast the scalar to element type 466 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType(); 467 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 468 469 // Insert the element in element zero of an undef vector 470 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 471 llvm::Value *Idx = 472 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0); 473 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 474 475 // Splat the element across to all elements 476 llvm::SmallVector<llvm::Constant*, 16> Args; 477 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 478 for (unsigned i = 0; i < NumElements; i++) 479 Args.push_back(llvm::ConstantInt::get( 480 llvm::Type::getInt32Ty(VMContext), 0)); 481 482 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 483 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 484 return Yay; 485 } 486 487 // Allow bitcast from vector to integer/fp of the same size. 488 if (isa<llvm::VectorType>(Src->getType()) || 489 isa<llvm::VectorType>(DstTy)) 490 return Builder.CreateBitCast(Src, DstTy, "conv"); 491 492 // Finally, we have the arithmetic types: real int/float. 493 if (isa<llvm::IntegerType>(Src->getType())) { 494 bool InputSigned = SrcType->isSignedIntegerType(); 495 if (isa<llvm::IntegerType>(DstTy)) 496 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 497 else if (InputSigned) 498 return Builder.CreateSIToFP(Src, DstTy, "conv"); 499 else 500 return Builder.CreateUIToFP(Src, DstTy, "conv"); 501 } 502 503 assert(Src->getType()->isFloatingPoint() && "Unknown real conversion"); 504 if (isa<llvm::IntegerType>(DstTy)) { 505 if (DstType->isSignedIntegerType()) 506 return Builder.CreateFPToSI(Src, DstTy, "conv"); 507 else 508 return Builder.CreateFPToUI(Src, DstTy, "conv"); 509 } 510 511 assert(DstTy->isFloatingPoint() && "Unknown real conversion"); 512 if (DstTy->getTypeID() < Src->getType()->getTypeID()) 513 return Builder.CreateFPTrunc(Src, DstTy, "conv"); 514 else 515 return Builder.CreateFPExt(Src, DstTy, "conv"); 516} 517 518/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 519/// type to the specified destination type, where the destination type is an 520/// LLVM scalar type. 521Value *ScalarExprEmitter:: 522EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 523 QualType SrcTy, QualType DstTy) { 524 // Get the source element type. 525 SrcTy = SrcTy->getAs<ComplexType>()->getElementType(); 526 527 // Handle conversions to bool first, they are special: comparisons against 0. 528 if (DstTy->isBooleanType()) { 529 // Complex != 0 -> (Real != 0) | (Imag != 0) 530 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 531 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 532 return Builder.CreateOr(Src.first, Src.second, "tobool"); 533 } 534 535 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 536 // the imaginary part of the complex value is discarded and the value of the 537 // real part is converted according to the conversion rules for the 538 // corresponding real type. 539 return EmitScalarConversion(Src.first, SrcTy, DstTy); 540} 541 542 543//===----------------------------------------------------------------------===// 544// Visitor Methods 545//===----------------------------------------------------------------------===// 546 547Value *ScalarExprEmitter::VisitExpr(Expr *E) { 548 CGF.ErrorUnsupported(E, "scalar expression"); 549 if (E->getType()->isVoidType()) 550 return 0; 551 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 552} 553 554Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 555 llvm::SmallVector<llvm::Constant*, 32> indices; 556 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 557 indices.push_back(cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i)))); 558 } 559 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 560 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 561 Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); 562 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 563} 564Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { 565 Expr::EvalResult Result; 566 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 567 if (E->isArrow()) 568 CGF.EmitScalarExpr(E->getBase()); 569 else 570 EmitLValue(E->getBase()); 571 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 572 } 573 return EmitLoadOfLValue(E); 574} 575 576Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 577 TestAndClearIgnoreResultAssign(); 578 579 // Emit subscript expressions in rvalue context's. For most cases, this just 580 // loads the lvalue formed by the subscript expr. However, we have to be 581 // careful, because the base of a vector subscript is occasionally an rvalue, 582 // so we can't get it as an lvalue. 583 if (!E->getBase()->getType()->isVectorType()) 584 return EmitLoadOfLValue(E); 585 586 // Handle the vector case. The base must be a vector, the index must be an 587 // integer value. 588 Value *Base = Visit(E->getBase()); 589 Value *Idx = Visit(E->getIdx()); 590 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerType(); 591 Idx = Builder.CreateIntCast(Idx, 592 llvm::Type::getInt32Ty(CGF.getLLVMContext()), 593 IdxSigned, 594 "vecidxcast"); 595 return Builder.CreateExtractElement(Base, Idx, "vecext"); 596} 597 598static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, 599 unsigned Off, const llvm::Type *I32Ty) { 600 int MV = SVI->getMaskValue(Idx); 601 if (MV == -1) 602 return llvm::UndefValue::get(I32Ty); 603 return llvm::ConstantInt::get(I32Ty, Off+MV); 604} 605 606Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) { 607 bool Ignore = TestAndClearIgnoreResultAssign(); 608 (void)Ignore; 609 assert (Ignore == false && "init list ignored"); 610 unsigned NumInitElements = E->getNumInits(); 611 612 if (E->hadArrayRangeDesignator()) 613 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 614 615 const llvm::VectorType *VType = 616 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 617 618 // We have a scalar in braces. Just use the first element. 619 if (!VType) 620 return Visit(E->getInit(0)); 621 622 unsigned ResElts = VType->getNumElements(); 623 const llvm::Type *I32Ty = llvm::Type::getInt32Ty(CGF.getLLVMContext()); 624 625 // Loop over initializers collecting the Value for each, and remembering 626 // whether the source was swizzle (ExtVectorElementExpr). This will allow 627 // us to fold the shuffle for the swizzle into the shuffle for the vector 628 // initializer, since LLVM optimizers generally do not want to touch 629 // shuffles. 630 unsigned CurIdx = 0; 631 bool VIsUndefShuffle = false; 632 llvm::Value *V = llvm::UndefValue::get(VType); 633 for (unsigned i = 0; i != NumInitElements; ++i) { 634 Expr *IE = E->getInit(i); 635 Value *Init = Visit(IE); 636 llvm::SmallVector<llvm::Constant*, 16> Args; 637 638 const llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType()); 639 640 // Handle scalar elements. If the scalar initializer is actually one 641 // element of a different vector of the same width, use shuffle instead of 642 // extract+insert. 643 if (!VVT) { 644 if (isa<ExtVectorElementExpr>(IE)) { 645 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init); 646 647 if (EI->getVectorOperandType()->getNumElements() == ResElts) { 648 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand()); 649 Value *LHS = 0, *RHS = 0; 650 if (CurIdx == 0) { 651 // insert into undef -> shuffle (src, undef) 652 Args.push_back(C); 653 for (unsigned j = 1; j != ResElts; ++j) 654 Args.push_back(llvm::UndefValue::get(I32Ty)); 655 656 LHS = EI->getVectorOperand(); 657 RHS = V; 658 VIsUndefShuffle = true; 659 } else if (VIsUndefShuffle) { 660 // insert into undefshuffle && size match -> shuffle (v, src) 661 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V); 662 for (unsigned j = 0; j != CurIdx; ++j) 663 Args.push_back(getMaskElt(SVV, j, 0, I32Ty)); 664 Args.push_back(llvm::ConstantInt::get(I32Ty, 665 ResElts + C->getZExtValue())); 666 for (unsigned j = CurIdx + 1; j != ResElts; ++j) 667 Args.push_back(llvm::UndefValue::get(I32Ty)); 668 669 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 670 RHS = EI->getVectorOperand(); 671 VIsUndefShuffle = false; 672 } 673 if (!Args.empty()) { 674 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 675 V = Builder.CreateShuffleVector(LHS, RHS, Mask); 676 ++CurIdx; 677 continue; 678 } 679 } 680 } 681 Value *Idx = llvm::ConstantInt::get(I32Ty, CurIdx); 682 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 683 VIsUndefShuffle = false; 684 ++CurIdx; 685 continue; 686 } 687 688 unsigned InitElts = VVT->getNumElements(); 689 690 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's 691 // input is the same width as the vector being constructed, generate an 692 // optimized shuffle of the swizzle input into the result. 693 unsigned Offset = (CurIdx == 0) ? 0 : ResElts; 694 if (isa<ExtVectorElementExpr>(IE)) { 695 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init); 696 Value *SVOp = SVI->getOperand(0); 697 const llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType()); 698 699 if (OpTy->getNumElements() == ResElts) { 700 for (unsigned j = 0; j != CurIdx; ++j) { 701 // If the current vector initializer is a shuffle with undef, merge 702 // this shuffle directly into it. 703 if (VIsUndefShuffle) { 704 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0, 705 I32Ty)); 706 } else { 707 Args.push_back(llvm::ConstantInt::get(I32Ty, j)); 708 } 709 } 710 for (unsigned j = 0, je = InitElts; j != je; ++j) 711 Args.push_back(getMaskElt(SVI, j, Offset, I32Ty)); 712 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 713 Args.push_back(llvm::UndefValue::get(I32Ty)); 714 715 if (VIsUndefShuffle) 716 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 717 718 Init = SVOp; 719 } 720 } 721 722 // Extend init to result vector length, and then shuffle its contribution 723 // to the vector initializer into V. 724 if (Args.empty()) { 725 for (unsigned j = 0; j != InitElts; ++j) 726 Args.push_back(llvm::ConstantInt::get(I32Ty, j)); 727 for (unsigned j = InitElts; j != ResElts; ++j) 728 Args.push_back(llvm::UndefValue::get(I32Ty)); 729 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 730 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), 731 Mask, "vext"); 732 733 Args.clear(); 734 for (unsigned j = 0; j != CurIdx; ++j) 735 Args.push_back(llvm::ConstantInt::get(I32Ty, j)); 736 for (unsigned j = 0; j != InitElts; ++j) 737 Args.push_back(llvm::ConstantInt::get(I32Ty, j+Offset)); 738 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 739 Args.push_back(llvm::UndefValue::get(I32Ty)); 740 } 741 742 // If V is undef, make sure it ends up on the RHS of the shuffle to aid 743 // merging subsequent shuffles into this one. 744 if (CurIdx == 0) 745 std::swap(V, Init); 746 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 747 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); 748 VIsUndefShuffle = isa<llvm::UndefValue>(Init); 749 CurIdx += InitElts; 750 } 751 752 // FIXME: evaluate codegen vs. shuffling against constant null vector. 753 // Emit remaining default initializers. 754 const llvm::Type *EltTy = VType->getElementType(); 755 756 // Emit remaining default initializers 757 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { 758 Value *Idx = llvm::ConstantInt::get(I32Ty, CurIdx); 759 llvm::Value *Init = llvm::Constant::getNullValue(EltTy); 760 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 761 } 762 return V; 763} 764 765static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { 766 const Expr *E = CE->getSubExpr(); 767 768 if (isa<CXXThisExpr>(E)) { 769 // We always assume that 'this' is never null. 770 return false; 771 } 772 773 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { 774 // And that lvalue casts are never null. 775 if (ICE->isLvalueCast()) 776 return false; 777 } 778 779 return true; 780} 781 782// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 783// have to handle a more broad range of conversions than explicit casts, as they 784// handle things like function to ptr-to-function decay etc. 785Value *ScalarExprEmitter::EmitCastExpr(const CastExpr *CE) { 786 const Expr *E = CE->getSubExpr(); 787 QualType DestTy = CE->getType(); 788 CastExpr::CastKind Kind = CE->getCastKind(); 789 790 if (!DestTy->isVoidType()) 791 TestAndClearIgnoreResultAssign(); 792 793 // Since almost all cast kinds apply to scalars, this switch doesn't have 794 // a default case, so the compiler will warn on a missing case. The cases 795 // are in the same order as in the CastKind enum. 796 switch (Kind) { 797 case CastExpr::CK_Unknown: 798 //assert(0 && "Unknown cast kind!"); 799 break; 800 801 case CastExpr::CK_BitCast: { 802 Value *Src = Visit(const_cast<Expr*>(E)); 803 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 804 } 805 case CastExpr::CK_NoOp: 806 return Visit(const_cast<Expr*>(E)); 807 808 case CastExpr::CK_BaseToDerived: { 809 const CXXRecordDecl *BaseClassDecl = 810 E->getType()->getCXXRecordDeclForPointerType(); 811 const CXXRecordDecl *DerivedClassDecl = 812 DestTy->getCXXRecordDeclForPointerType(); 813 814 Value *Src = Visit(const_cast<Expr*>(E)); 815 816 bool NullCheckValue = ShouldNullCheckClassCastValue(CE); 817 return CGF.GetAddressOfDerivedClass(Src, BaseClassDecl, DerivedClassDecl, 818 NullCheckValue); 819 } 820 case CastExpr::CK_DerivedToBase: { 821 const RecordType *DerivedClassTy = 822 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 823 CXXRecordDecl *DerivedClassDecl = 824 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 825 826 const RecordType *BaseClassTy = 827 DestTy->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 828 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseClassTy->getDecl()); 829 830 Value *Src = Visit(const_cast<Expr*>(E)); 831 832 bool NullCheckValue = ShouldNullCheckClassCastValue(CE); 833 return CGF.GetAddressOfBaseClass(Src, DerivedClassDecl, BaseClassDecl, 834 NullCheckValue); 835 } 836 case CastExpr::CK_Dynamic: { 837 Value *V = Visit(const_cast<Expr*>(E)); 838 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 839 return CGF.EmitDynamicCast(V, DCE); 840 } 841 case CastExpr::CK_ToUnion: { 842 assert(0 && "Should be unreachable!"); 843 break; 844 } 845 case CastExpr::CK_ArrayToPointerDecay: { 846 assert(E->getType()->isArrayType() && 847 "Array to pointer decay must have array source type!"); 848 849 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 850 851 // Note that VLA pointers are always decayed, so we don't need to do 852 // anything here. 853 if (!E->getType()->isVariableArrayType()) { 854 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 855 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 856 ->getElementType()) && 857 "Expected pointer to array"); 858 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 859 } 860 861 return V; 862 } 863 case CastExpr::CK_FunctionToPointerDecay: 864 return EmitLValue(E).getAddress(); 865 866 case CastExpr::CK_NullToMemberPointer: 867 return CGF.CGM.EmitNullConstant(DestTy); 868 869 case CastExpr::CK_BaseToDerivedMemberPointer: 870 case CastExpr::CK_DerivedToBaseMemberPointer: 871 case CastExpr::CK_UserDefinedConversion: 872 case CastExpr::CK_ConstructorConversion: 873 break; 874 875 case CastExpr::CK_IntegralToPointer: { 876 Value *Src = Visit(const_cast<Expr*>(E)); 877 878 // First, convert to the correct width so that we control the kind of 879 // extension. 880 const llvm::Type *MiddleTy = 881 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 882 bool InputSigned = E->getType()->isSignedIntegerType(); 883 llvm::Value* IntResult = 884 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 885 886 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 887 } 888 case CastExpr::CK_PointerToIntegral: { 889 Value *Src = Visit(const_cast<Expr*>(E)); 890 return Builder.CreatePtrToInt(Src, ConvertType(DestTy)); 891 } 892 case CastExpr::CK_ToVoid: { 893 CGF.EmitAnyExpr(E, 0, false, true); 894 return 0; 895 } 896 case CastExpr::CK_VectorSplat: { 897 const llvm::Type *DstTy = ConvertType(DestTy); 898 Value *Elt = Visit(const_cast<Expr*>(E)); 899 900 // Insert the element in element zero of an undef vector 901 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 902 llvm::Value *Idx = 903 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0); 904 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 905 906 // Splat the element across to all elements 907 llvm::SmallVector<llvm::Constant*, 16> Args; 908 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 909 for (unsigned i = 0; i < NumElements; i++) 910 Args.push_back(llvm::ConstantInt::get( 911 llvm::Type::getInt32Ty(VMContext), 0)); 912 913 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 914 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 915 return Yay; 916 } 917 case CastExpr::CK_IntegralCast: 918 case CastExpr::CK_IntegralToFloating: 919 case CastExpr::CK_FloatingToIntegral: 920 case CastExpr::CK_FloatingCast: 921 break; 922 923 case CastExpr::CK_MemberPointerToBoolean: { 924 const MemberPointerType* T = E->getType()->getAs<MemberPointerType>(); 925 926 if (T->getPointeeType()->isFunctionType()) { 927 // We have a member function pointer. 928 llvm::Value *Ptr = CGF.CreateTempAlloca(ConvertType(E->getType())); 929 930 CGF.EmitAggExpr(E, Ptr, /*VolatileDest=*/false); 931 932 // Get the pointer. 933 llvm::Value *FuncPtr = Builder.CreateStructGEP(Ptr, 0, "src.ptr"); 934 FuncPtr = Builder.CreateLoad(FuncPtr); 935 936 llvm::Value *IsNotNull = 937 Builder.CreateICmpNE(FuncPtr, 938 llvm::Constant::getNullValue(FuncPtr->getType()), 939 "tobool"); 940 941 return IsNotNull; 942 } 943 944 // We have a regular member pointer. 945 Value *Ptr = Visit(const_cast<Expr*>(E)); 946 llvm::Value *IsNotNull = 947 Builder.CreateICmpNE(Ptr, CGF.CGM.EmitNullConstant(E->getType()), 948 "tobool"); 949 return IsNotNull; 950 } 951 } 952 953 // Handle cases where the source is an non-complex type. 954 955 if (!CGF.hasAggregateLLVMType(E->getType())) { 956 Value *Src = Visit(const_cast<Expr*>(E)); 957 958 // Use EmitScalarConversion to perform the conversion. 959 return EmitScalarConversion(Src, E->getType(), DestTy); 960 } 961 962 if (E->getType()->isAnyComplexType()) { 963 // Handle cases where the source is a complex type. 964 bool IgnoreImag = true; 965 bool IgnoreImagAssign = true; 966 bool IgnoreReal = IgnoreResultAssign; 967 bool IgnoreRealAssign = IgnoreResultAssign; 968 if (DestTy->isBooleanType()) 969 IgnoreImagAssign = IgnoreImag = false; 970 else if (DestTy->isVoidType()) { 971 IgnoreReal = IgnoreImag = false; 972 IgnoreRealAssign = IgnoreImagAssign = true; 973 } 974 CodeGenFunction::ComplexPairTy V 975 = CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign, 976 IgnoreImagAssign); 977 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 978 } 979 980 // Okay, this is a cast from an aggregate. It must be a cast to void. Just 981 // evaluate the result and return. 982 CGF.EmitAggExpr(E, 0, false, true); 983 return 0; 984} 985 986Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 987 return CGF.EmitCompoundStmt(*E->getSubStmt(), 988 !E->getType()->isVoidType()).getScalarVal(); 989} 990 991Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 992 llvm::Value *V = CGF.GetAddrOfBlockDecl(E); 993 if (E->getType().isObjCGCWeak()) 994 return CGF.CGM.getObjCRuntime().EmitObjCWeakRead(CGF, V); 995 return Builder.CreateLoad(V, false, "tmp"); 996} 997 998//===----------------------------------------------------------------------===// 999// Unary Operators 1000//===----------------------------------------------------------------------===// 1001 1002Value *ScalarExprEmitter::VisitPrePostIncDec(const UnaryOperator *E, 1003 bool isInc, bool isPre) { 1004 LValue LV = EmitLValue(E->getSubExpr()); 1005 QualType ValTy = E->getSubExpr()->getType(); 1006 Value *InVal = CGF.EmitLoadOfLValue(LV, ValTy).getScalarVal(); 1007 1008 llvm::LLVMContext &VMContext = CGF.getLLVMContext(); 1009 1010 int AmountVal = isInc ? 1 : -1; 1011 1012 if (ValTy->isPointerType() && 1013 ValTy->getAs<PointerType>()->isVariableArrayType()) { 1014 // The amount of the addition/subtraction needs to account for the VLA size 1015 CGF.ErrorUnsupported(E, "VLA pointer inc/dec"); 1016 } 1017 1018 Value *NextVal; 1019 if (const llvm::PointerType *PT = 1020 dyn_cast<llvm::PointerType>(InVal->getType())) { 1021 llvm::Constant *Inc = 1022 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), AmountVal); 1023 if (!isa<llvm::FunctionType>(PT->getElementType())) { 1024 QualType PTEE = ValTy->getPointeeType(); 1025 if (const ObjCInterfaceType *OIT = 1026 dyn_cast<ObjCInterfaceType>(PTEE)) { 1027 // Handle interface types, which are not represented with a concrete type. 1028 int size = CGF.getContext().getTypeSize(OIT) / 8; 1029 if (!isInc) 1030 size = -size; 1031 Inc = llvm::ConstantInt::get(Inc->getType(), size); 1032 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1033 InVal = Builder.CreateBitCast(InVal, i8Ty); 1034 NextVal = Builder.CreateGEP(InVal, Inc, "add.ptr"); 1035 llvm::Value *lhs = LV.getAddress(); 1036 lhs = Builder.CreateBitCast(lhs, llvm::PointerType::getUnqual(i8Ty)); 1037 LV = LValue::MakeAddr(lhs, CGF.MakeQualifiers(ValTy)); 1038 } else 1039 NextVal = Builder.CreateInBoundsGEP(InVal, Inc, "ptrincdec"); 1040 } else { 1041 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1042 NextVal = Builder.CreateBitCast(InVal, i8Ty, "tmp"); 1043 NextVal = Builder.CreateGEP(NextVal, Inc, "ptrincdec"); 1044 NextVal = Builder.CreateBitCast(NextVal, InVal->getType()); 1045 } 1046 } else if (InVal->getType() == llvm::Type::getInt1Ty(VMContext) && isInc) { 1047 // Bool++ is an interesting case, due to promotion rules, we get: 1048 // Bool++ -> Bool = Bool+1 -> Bool = (int)Bool+1 -> 1049 // Bool = ((int)Bool+1) != 0 1050 // An interesting aspect of this is that increment is always true. 1051 // Decrement does not have this property. 1052 NextVal = llvm::ConstantInt::getTrue(VMContext); 1053 } else if (isa<llvm::IntegerType>(InVal->getType())) { 1054 NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); 1055 1056 // Signed integer overflow is undefined behavior. 1057 if (ValTy->isSignedIntegerType()) 1058 NextVal = Builder.CreateNSWAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1059 else 1060 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1061 } else { 1062 // Add the inc/dec to the real part. 1063 if (InVal->getType()->isFloatTy()) 1064 NextVal = 1065 llvm::ConstantFP::get(VMContext, 1066 llvm::APFloat(static_cast<float>(AmountVal))); 1067 else if (InVal->getType()->isDoubleTy()) 1068 NextVal = 1069 llvm::ConstantFP::get(VMContext, 1070 llvm::APFloat(static_cast<double>(AmountVal))); 1071 else { 1072 llvm::APFloat F(static_cast<float>(AmountVal)); 1073 bool ignored; 1074 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, 1075 &ignored); 1076 NextVal = llvm::ConstantFP::get(VMContext, F); 1077 } 1078 NextVal = Builder.CreateFAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1079 } 1080 1081 // Store the updated result through the lvalue. 1082 if (LV.isBitfield()) 1083 CGF.EmitStoreThroughBitfieldLValue(RValue::get(NextVal), LV, ValTy, 1084 &NextVal); 1085 else 1086 CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV, ValTy); 1087 1088 // If this is a postinc, return the value read from memory, otherwise use the 1089 // updated value. 1090 return isPre ? NextVal : InVal; 1091} 1092 1093 1094Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1095 TestAndClearIgnoreResultAssign(); 1096 Value *Op = Visit(E->getSubExpr()); 1097 if (Op->getType()->isFPOrFPVector()) 1098 return Builder.CreateFNeg(Op, "neg"); 1099 return Builder.CreateNeg(Op, "neg"); 1100} 1101 1102Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1103 TestAndClearIgnoreResultAssign(); 1104 Value *Op = Visit(E->getSubExpr()); 1105 return Builder.CreateNot(Op, "neg"); 1106} 1107 1108Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1109 // Compare operand to zero. 1110 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1111 1112 // Invert value. 1113 // TODO: Could dynamically modify easy computations here. For example, if 1114 // the operand is an icmp ne, turn into icmp eq. 1115 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1116 1117 // ZExt result to the expr type. 1118 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1119} 1120 1121/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of 1122/// argument of the sizeof expression as an integer. 1123Value * 1124ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { 1125 QualType TypeToSize = E->getTypeOfArgument(); 1126 if (E->isSizeOf()) { 1127 if (const VariableArrayType *VAT = 1128 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1129 if (E->isArgumentType()) { 1130 // sizeof(type) - make sure to emit the VLA size. 1131 CGF.EmitVLASize(TypeToSize); 1132 } else { 1133 // C99 6.5.3.4p2: If the argument is an expression of type 1134 // VLA, it is evaluated. 1135 CGF.EmitAnyExpr(E->getArgumentExpr()); 1136 } 1137 1138 return CGF.GetVLASize(VAT); 1139 } 1140 } 1141 1142 // If this isn't sizeof(vla), the result must be constant; use the constant 1143 // folding logic so we don't have to duplicate it here. 1144 Expr::EvalResult Result; 1145 E->Evaluate(Result, CGF.getContext()); 1146 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 1147} 1148 1149Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1150 Expr *Op = E->getSubExpr(); 1151 if (Op->getType()->isAnyComplexType()) 1152 return CGF.EmitComplexExpr(Op, false, true, false, true).first; 1153 return Visit(Op); 1154} 1155Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1156 Expr *Op = E->getSubExpr(); 1157 if (Op->getType()->isAnyComplexType()) 1158 return CGF.EmitComplexExpr(Op, true, false, true, false).second; 1159 1160 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1161 // effects are evaluated, but not the actual value. 1162 if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) 1163 CGF.EmitLValue(Op); 1164 else 1165 CGF.EmitScalarExpr(Op, true); 1166 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1167} 1168 1169Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) { 1170 Value* ResultAsPtr = EmitLValue(E->getSubExpr()).getAddress(); 1171 const llvm::Type* ResultType = ConvertType(E->getType()); 1172 return Builder.CreatePtrToInt(ResultAsPtr, ResultType, "offsetof"); 1173} 1174 1175//===----------------------------------------------------------------------===// 1176// Binary Operators 1177//===----------------------------------------------------------------------===// 1178 1179BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1180 TestAndClearIgnoreResultAssign(); 1181 BinOpInfo Result; 1182 Result.LHS = Visit(E->getLHS()); 1183 Result.RHS = Visit(E->getRHS()); 1184 Result.Ty = E->getType(); 1185 Result.E = E; 1186 return Result; 1187} 1188 1189Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 1190 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 1191 bool Ignore = TestAndClearIgnoreResultAssign(); 1192 QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType(); 1193 1194 BinOpInfo OpInfo; 1195 1196 if (E->getComputationResultType()->isAnyComplexType()) { 1197 // This needs to go through the complex expression emitter, but it's a tad 1198 // complicated to do that... I'm leaving it out for now. (Note that we do 1199 // actually need the imaginary part of the RHS for multiplication and 1200 // division.) 1201 CGF.ErrorUnsupported(E, "complex compound assignment"); 1202 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 1203 } 1204 1205 // Emit the RHS first. __block variables need to have the rhs evaluated 1206 // first, plus this should improve codegen a little. 1207 OpInfo.RHS = Visit(E->getRHS()); 1208 OpInfo.Ty = E->getComputationResultType(); 1209 OpInfo.E = E; 1210 // Load/convert the LHS. 1211 LValue LHSLV = EmitLValue(E->getLHS()); 1212 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 1213 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 1214 E->getComputationLHSType()); 1215 1216 // Expand the binary operator. 1217 Value *Result = (this->*Func)(OpInfo); 1218 1219 // Convert the result back to the LHS type. 1220 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 1221 1222 // Store the result value into the LHS lvalue. Bit-fields are handled 1223 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 1224 // 'An assignment expression has the value of the left operand after the 1225 // assignment...'. 1226 if (LHSLV.isBitfield()) { 1227 if (!LHSLV.isVolatileQualified()) { 1228 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, 1229 &Result); 1230 return Result; 1231 } else 1232 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy); 1233 } else 1234 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); 1235 if (Ignore) 1236 return 0; 1237 return EmitLoadOfLValue(LHSLV, E->getType()); 1238} 1239 1240 1241Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 1242 if (Ops.LHS->getType()->isFPOrFPVector()) 1243 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 1244 else if (Ops.Ty->isUnsignedIntegerType()) 1245 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 1246 else 1247 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 1248} 1249 1250Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 1251 // Rem in C can't be a floating point type: C99 6.5.5p2. 1252 if (Ops.Ty->isUnsignedIntegerType()) 1253 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 1254 else 1255 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 1256} 1257 1258Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 1259 unsigned IID; 1260 unsigned OpID = 0; 1261 1262 switch (Ops.E->getOpcode()) { 1263 case BinaryOperator::Add: 1264 case BinaryOperator::AddAssign: 1265 OpID = 1; 1266 IID = llvm::Intrinsic::sadd_with_overflow; 1267 break; 1268 case BinaryOperator::Sub: 1269 case BinaryOperator::SubAssign: 1270 OpID = 2; 1271 IID = llvm::Intrinsic::ssub_with_overflow; 1272 break; 1273 case BinaryOperator::Mul: 1274 case BinaryOperator::MulAssign: 1275 OpID = 3; 1276 IID = llvm::Intrinsic::smul_with_overflow; 1277 break; 1278 default: 1279 assert(false && "Unsupported operation for overflow detection"); 1280 IID = 0; 1281 } 1282 OpID <<= 1; 1283 OpID |= 1; 1284 1285 const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1286 1287 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1); 1288 1289 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1290 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1291 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1292 1293 // Branch in case of overflow. 1294 llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); 1295 llvm::BasicBlock *overflowBB = 1296 CGF.createBasicBlock("overflow", CGF.CurFn); 1297 llvm::BasicBlock *continueBB = 1298 CGF.createBasicBlock("overflow.continue", CGF.CurFn); 1299 1300 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1301 1302 // Handle overflow 1303 1304 Builder.SetInsertPoint(overflowBB); 1305 1306 // Handler is: 1307 // long long *__overflow_handler)(long long a, long long b, char op, 1308 // char width) 1309 std::vector<const llvm::Type*> handerArgTypes; 1310 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1311 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1312 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1313 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1314 llvm::FunctionType *handlerTy = llvm::FunctionType::get( 1315 llvm::Type::getInt64Ty(VMContext), handerArgTypes, false); 1316 llvm::Value *handlerFunction = 1317 CGF.CGM.getModule().getOrInsertGlobal("__overflow_handler", 1318 llvm::PointerType::getUnqual(handlerTy)); 1319 handlerFunction = Builder.CreateLoad(handlerFunction); 1320 1321 llvm::Value *handlerResult = Builder.CreateCall4(handlerFunction, 1322 Builder.CreateSExt(Ops.LHS, llvm::Type::getInt64Ty(VMContext)), 1323 Builder.CreateSExt(Ops.RHS, llvm::Type::getInt64Ty(VMContext)), 1324 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), OpID), 1325 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), 1326 cast<llvm::IntegerType>(opTy)->getBitWidth())); 1327 1328 handlerResult = Builder.CreateTrunc(handlerResult, opTy); 1329 1330 Builder.CreateBr(continueBB); 1331 1332 // Set up the continuation 1333 Builder.SetInsertPoint(continueBB); 1334 // Get the correct result 1335 llvm::PHINode *phi = Builder.CreatePHI(opTy); 1336 phi->reserveOperandSpace(2); 1337 phi->addIncoming(result, initialBB); 1338 phi->addIncoming(handlerResult, overflowBB); 1339 1340 return phi; 1341} 1342 1343Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 1344 if (!Ops.Ty->isAnyPointerType()) { 1345 if (CGF.getContext().getLangOptions().OverflowChecking && 1346 Ops.Ty->isSignedIntegerType()) 1347 return EmitOverflowCheckedBinOp(Ops); 1348 1349 if (Ops.LHS->getType()->isFPOrFPVector()) 1350 return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add"); 1351 1352 // Signed integer overflow is undefined behavior. 1353 if (Ops.Ty->isSignedIntegerType()) 1354 return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add"); 1355 1356 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1357 } 1358 1359 if (Ops.Ty->isPointerType() && 1360 Ops.Ty->getAs<PointerType>()->isVariableArrayType()) { 1361 // The amount of the addition needs to account for the VLA size 1362 CGF.ErrorUnsupported(Ops.E, "VLA pointer addition"); 1363 } 1364 Value *Ptr, *Idx; 1365 Expr *IdxExp; 1366 const PointerType *PT = Ops.E->getLHS()->getType()->getAs<PointerType>(); 1367 const ObjCObjectPointerType *OPT = 1368 Ops.E->getLHS()->getType()->getAs<ObjCObjectPointerType>(); 1369 if (PT || OPT) { 1370 Ptr = Ops.LHS; 1371 Idx = Ops.RHS; 1372 IdxExp = Ops.E->getRHS(); 1373 } else { // int + pointer 1374 PT = Ops.E->getRHS()->getType()->getAs<PointerType>(); 1375 OPT = Ops.E->getRHS()->getType()->getAs<ObjCObjectPointerType>(); 1376 assert((PT || OPT) && "Invalid add expr"); 1377 Ptr = Ops.RHS; 1378 Idx = Ops.LHS; 1379 IdxExp = Ops.E->getLHS(); 1380 } 1381 1382 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1383 if (Width < CGF.LLVMPointerWidth) { 1384 // Zero or sign extend the pointer value based on whether the index is 1385 // signed or not. 1386 const llvm::Type *IdxType = 1387 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1388 if (IdxExp->getType()->isSignedIntegerType()) 1389 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1390 else 1391 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1392 } 1393 const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType(); 1394 // Handle interface types, which are not represented with a concrete type. 1395 if (const ObjCInterfaceType *OIT = dyn_cast<ObjCInterfaceType>(ElementType)) { 1396 llvm::Value *InterfaceSize = 1397 llvm::ConstantInt::get(Idx->getType(), 1398 CGF.getContext().getTypeSize(OIT) / 8); 1399 Idx = Builder.CreateMul(Idx, InterfaceSize); 1400 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1401 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1402 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1403 return Builder.CreateBitCast(Res, Ptr->getType()); 1404 } 1405 1406 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 1407 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 1408 // future proof. 1409 if (ElementType->isVoidType() || ElementType->isFunctionType()) { 1410 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1411 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1412 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1413 return Builder.CreateBitCast(Res, Ptr->getType()); 1414 } 1415 1416 return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr"); 1417} 1418 1419Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 1420 if (!isa<llvm::PointerType>(Ops.LHS->getType())) { 1421 if (CGF.getContext().getLangOptions().OverflowChecking 1422 && Ops.Ty->isSignedIntegerType()) 1423 return EmitOverflowCheckedBinOp(Ops); 1424 1425 if (Ops.LHS->getType()->isFPOrFPVector()) 1426 return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub"); 1427 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1428 } 1429 1430 if (Ops.E->getLHS()->getType()->isPointerType() && 1431 Ops.E->getLHS()->getType()->getAs<PointerType>()->isVariableArrayType()) { 1432 // The amount of the addition needs to account for the VLA size for 1433 // ptr-int 1434 // The amount of the division needs to account for the VLA size for 1435 // ptr-ptr. 1436 CGF.ErrorUnsupported(Ops.E, "VLA pointer subtraction"); 1437 } 1438 1439 const QualType LHSType = Ops.E->getLHS()->getType(); 1440 const QualType LHSElementType = LHSType->getPointeeType(); 1441 if (!isa<llvm::PointerType>(Ops.RHS->getType())) { 1442 // pointer - int 1443 Value *Idx = Ops.RHS; 1444 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1445 if (Width < CGF.LLVMPointerWidth) { 1446 // Zero or sign extend the pointer value based on whether the index is 1447 // signed or not. 1448 const llvm::Type *IdxType = 1449 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1450 if (Ops.E->getRHS()->getType()->isSignedIntegerType()) 1451 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1452 else 1453 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1454 } 1455 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); 1456 1457 // Handle interface types, which are not represented with a concrete type. 1458 if (const ObjCInterfaceType *OIT = 1459 dyn_cast<ObjCInterfaceType>(LHSElementType)) { 1460 llvm::Value *InterfaceSize = 1461 llvm::ConstantInt::get(Idx->getType(), 1462 CGF.getContext().getTypeSize(OIT) / 8); 1463 Idx = Builder.CreateMul(Idx, InterfaceSize); 1464 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1465 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1466 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr"); 1467 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1468 } 1469 1470 // Explicitly handle GNU void* and function pointer arithmetic 1471 // extensions. The GNU void* casts amount to no-ops since our void* type is 1472 // i8*, but this is future proof. 1473 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1474 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1475 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1476 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); 1477 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1478 } 1479 1480 return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr"); 1481 } else { 1482 // pointer - pointer 1483 Value *LHS = Ops.LHS; 1484 Value *RHS = Ops.RHS; 1485 1486 uint64_t ElementSize; 1487 1488 // Handle GCC extension for pointer arithmetic on void* and function pointer 1489 // types. 1490 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1491 ElementSize = 1; 1492 } else { 1493 ElementSize = CGF.getContext().getTypeSize(LHSElementType) / 8; 1494 } 1495 1496 const llvm::Type *ResultType = ConvertType(Ops.Ty); 1497 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 1498 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 1499 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 1500 1501 // Optimize out the shift for element size of 1. 1502 if (ElementSize == 1) 1503 return BytesBetween; 1504 1505 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 1506 // pointer difference in C is only defined in the case where both operands 1507 // are pointing to elements of an array. 1508 Value *BytesPerElt = llvm::ConstantInt::get(ResultType, ElementSize); 1509 return Builder.CreateExactSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 1510 } 1511} 1512 1513Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 1514 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1515 // RHS to the same size as the LHS. 1516 Value *RHS = Ops.RHS; 1517 if (Ops.LHS->getType() != RHS->getType()) 1518 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1519 1520 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 1521} 1522 1523Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 1524 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1525 // RHS to the same size as the LHS. 1526 Value *RHS = Ops.RHS; 1527 if (Ops.LHS->getType() != RHS->getType()) 1528 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1529 1530 if (Ops.Ty->isUnsignedIntegerType()) 1531 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 1532 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 1533} 1534 1535Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 1536 unsigned SICmpOpc, unsigned FCmpOpc) { 1537 TestAndClearIgnoreResultAssign(); 1538 Value *Result; 1539 QualType LHSTy = E->getLHS()->getType(); 1540 if (!LHSTy->isAnyComplexType()) { 1541 Value *LHS = Visit(E->getLHS()); 1542 Value *RHS = Visit(E->getRHS()); 1543 1544 if (LHS->getType()->isFPOrFPVector()) { 1545 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 1546 LHS, RHS, "cmp"); 1547 } else if (LHSTy->isSignedIntegerType()) { 1548 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 1549 LHS, RHS, "cmp"); 1550 } else { 1551 // Unsigned integers and pointers. 1552 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1553 LHS, RHS, "cmp"); 1554 } 1555 1556 // If this is a vector comparison, sign extend the result to the appropriate 1557 // vector integer type and return it (don't convert to bool). 1558 if (LHSTy->isVectorType()) 1559 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 1560 1561 } else { 1562 // Complex Comparison: can only be an equality comparison. 1563 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 1564 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 1565 1566 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 1567 1568 Value *ResultR, *ResultI; 1569 if (CETy->isRealFloatingType()) { 1570 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1571 LHS.first, RHS.first, "cmp.r"); 1572 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1573 LHS.second, RHS.second, "cmp.i"); 1574 } else { 1575 // Complex comparisons can only be equality comparisons. As such, signed 1576 // and unsigned opcodes are the same. 1577 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1578 LHS.first, RHS.first, "cmp.r"); 1579 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1580 LHS.second, RHS.second, "cmp.i"); 1581 } 1582 1583 if (E->getOpcode() == BinaryOperator::EQ) { 1584 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 1585 } else { 1586 assert(E->getOpcode() == BinaryOperator::NE && 1587 "Complex comparison other than == or != ?"); 1588 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 1589 } 1590 } 1591 1592 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 1593} 1594 1595Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 1596 bool Ignore = TestAndClearIgnoreResultAssign(); 1597 1598 // __block variables need to have the rhs evaluated first, plus this should 1599 // improve codegen just a little. 1600 Value *RHS = Visit(E->getRHS()); 1601 LValue LHS = EmitLValue(E->getLHS()); 1602 1603 // Store the value into the LHS. Bit-fields are handled specially 1604 // because the result is altered by the store, i.e., [C99 6.5.16p1] 1605 // 'An assignment expression has the value of the left operand after 1606 // the assignment...'. 1607 if (LHS.isBitfield()) { 1608 if (!LHS.isVolatileQualified()) { 1609 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), 1610 &RHS); 1611 return RHS; 1612 } else 1613 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType()); 1614 } else 1615 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 1616 if (Ignore) 1617 return 0; 1618 return EmitLoadOfLValue(LHS, E->getType()); 1619} 1620 1621Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 1622 const llvm::Type *ResTy = ConvertType(E->getType()); 1623 1624 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 1625 // If we have 1 && X, just emit X without inserting the control flow. 1626 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1627 if (Cond == 1) { // If we have 1 && X, just emit X. 1628 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1629 // ZExt result to int or bool. 1630 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 1631 } 1632 1633 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 1634 if (!CGF.ContainsLabel(E->getRHS())) 1635 return llvm::Constant::getNullValue(ResTy); 1636 } 1637 1638 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 1639 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 1640 1641 // Branch on the LHS first. If it is false, go to the failure (cont) block. 1642 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 1643 1644 // Any edges into the ContBlock are now from an (indeterminate number of) 1645 // edges from this first condition. All of these values will be false. Start 1646 // setting up the PHI node in the Cont Block for this. 1647 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1648 "", ContBlock); 1649 PN->reserveOperandSpace(2); // Normal case, two inputs. 1650 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1651 PI != PE; ++PI) 1652 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 1653 1654 CGF.StartConditionalBranch(); 1655 CGF.EmitBlock(RHSBlock); 1656 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1657 CGF.FinishConditionalBranch(); 1658 1659 // Reaquire the RHS block, as there may be subblocks inserted. 1660 RHSBlock = Builder.GetInsertBlock(); 1661 1662 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1663 // into the phi node for the edge with the value of RHSCond. 1664 CGF.EmitBlock(ContBlock); 1665 PN->addIncoming(RHSCond, RHSBlock); 1666 1667 // ZExt result to int. 1668 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); 1669} 1670 1671Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 1672 const llvm::Type *ResTy = ConvertType(E->getType()); 1673 1674 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 1675 // If we have 0 || X, just emit X without inserting the control flow. 1676 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1677 if (Cond == -1) { // If we have 0 || X, just emit X. 1678 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1679 // ZExt result to int or bool. 1680 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 1681 } 1682 1683 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 1684 if (!CGF.ContainsLabel(E->getRHS())) 1685 return llvm::ConstantInt::get(ResTy, 1); 1686 } 1687 1688 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 1689 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 1690 1691 // Branch on the LHS first. If it is true, go to the success (cont) block. 1692 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 1693 1694 // Any edges into the ContBlock are now from an (indeterminate number of) 1695 // edges from this first condition. All of these values will be true. Start 1696 // setting up the PHI node in the Cont Block for this. 1697 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1698 "", ContBlock); 1699 PN->reserveOperandSpace(2); // Normal case, two inputs. 1700 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1701 PI != PE; ++PI) 1702 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 1703 1704 CGF.StartConditionalBranch(); 1705 1706 // Emit the RHS condition as a bool value. 1707 CGF.EmitBlock(RHSBlock); 1708 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1709 1710 CGF.FinishConditionalBranch(); 1711 1712 // Reaquire the RHS block, as there may be subblocks inserted. 1713 RHSBlock = Builder.GetInsertBlock(); 1714 1715 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1716 // into the phi node for the edge with the value of RHSCond. 1717 CGF.EmitBlock(ContBlock); 1718 PN->addIncoming(RHSCond, RHSBlock); 1719 1720 // ZExt result to int. 1721 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 1722} 1723 1724Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 1725 CGF.EmitStmt(E->getLHS()); 1726 CGF.EnsureInsertPoint(); 1727 return Visit(E->getRHS()); 1728} 1729 1730//===----------------------------------------------------------------------===// 1731// Other Operators 1732//===----------------------------------------------------------------------===// 1733 1734/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 1735/// expression is cheap enough and side-effect-free enough to evaluate 1736/// unconditionally instead of conditionally. This is used to convert control 1737/// flow into selects in some cases. 1738static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 1739 CodeGenFunction &CGF) { 1740 if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) 1741 return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr(), CGF); 1742 1743 // TODO: Allow anything we can constant fold to an integer or fp constant. 1744 if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || 1745 isa<FloatingLiteral>(E)) 1746 return true; 1747 1748 // Non-volatile automatic variables too, to get "cond ? X : Y" where 1749 // X and Y are local variables. 1750 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 1751 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 1752 if (VD->hasLocalStorage() && !(CGF.getContext() 1753 .getCanonicalType(VD->getType()) 1754 .isVolatileQualified())) 1755 return true; 1756 1757 return false; 1758} 1759 1760 1761Value *ScalarExprEmitter:: 1762VisitConditionalOperator(const ConditionalOperator *E) { 1763 TestAndClearIgnoreResultAssign(); 1764 // If the condition constant folds and can be elided, try to avoid emitting 1765 // the condition and the dead arm. 1766 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ 1767 Expr *Live = E->getLHS(), *Dead = E->getRHS(); 1768 if (Cond == -1) 1769 std::swap(Live, Dead); 1770 1771 // If the dead side doesn't have labels we need, and if the Live side isn't 1772 // the gnu missing ?: extension (which we could handle, but don't bother 1773 // to), just emit the Live part. 1774 if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part 1775 Live) // Live part isn't missing. 1776 return Visit(Live); 1777 } 1778 1779 1780 // If this is a really simple expression (like x ? 4 : 5), emit this as a 1781 // select instead of as control flow. We can only do this if it is cheap and 1782 // safe to evaluate the LHS and RHS unconditionally. 1783 if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS(), 1784 CGF) && 1785 isCheapEnoughToEvaluateUnconditionally(E->getRHS(), CGF)) { 1786 llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); 1787 llvm::Value *LHS = Visit(E->getLHS()); 1788 llvm::Value *RHS = Visit(E->getRHS()); 1789 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 1790 } 1791 1792 1793 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 1794 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 1795 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 1796 Value *CondVal = 0; 1797 1798 // If we don't have the GNU missing condition extension, emit a branch on bool 1799 // the normal way. 1800 if (E->getLHS()) { 1801 // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for 1802 // the branch on bool. 1803 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); 1804 } else { 1805 // Otherwise, for the ?: extension, evaluate the conditional and then 1806 // convert it to bool the hard way. We do this explicitly because we need 1807 // the unconverted value for the missing middle value of the ?:. 1808 CondVal = CGF.EmitScalarExpr(E->getCond()); 1809 1810 // In some cases, EmitScalarConversion will delete the "CondVal" expression 1811 // if there are no extra uses (an optimization). Inhibit this by making an 1812 // extra dead use, because we're going to add a use of CondVal later. We 1813 // don't use the builder for this, because we don't want it to get optimized 1814 // away. This leaves dead code, but the ?: extension isn't common. 1815 new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", 1816 Builder.GetInsertBlock()); 1817 1818 Value *CondBoolVal = 1819 CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 1820 CGF.getContext().BoolTy); 1821 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 1822 } 1823 1824 CGF.StartConditionalBranch(); 1825 CGF.EmitBlock(LHSBlock); 1826 1827 // Handle the GNU extension for missing LHS. 1828 Value *LHS; 1829 if (E->getLHS()) 1830 LHS = Visit(E->getLHS()); 1831 else // Perform promotions, to handle cases like "short ?: int" 1832 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); 1833 1834 CGF.FinishConditionalBranch(); 1835 LHSBlock = Builder.GetInsertBlock(); 1836 CGF.EmitBranch(ContBlock); 1837 1838 CGF.StartConditionalBranch(); 1839 CGF.EmitBlock(RHSBlock); 1840 1841 Value *RHS = Visit(E->getRHS()); 1842 CGF.FinishConditionalBranch(); 1843 RHSBlock = Builder.GetInsertBlock(); 1844 CGF.EmitBranch(ContBlock); 1845 1846 CGF.EmitBlock(ContBlock); 1847 1848 if (!LHS || !RHS) { 1849 assert(E->getType()->isVoidType() && "Non-void value should have a value"); 1850 return 0; 1851 } 1852 1853 // Create a PHI node for the real part. 1854 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 1855 PN->reserveOperandSpace(2); 1856 PN->addIncoming(LHS, LHSBlock); 1857 PN->addIncoming(RHS, RHSBlock); 1858 return PN; 1859} 1860 1861Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 1862 return Visit(E->getChosenSubExpr(CGF.getContext())); 1863} 1864 1865Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 1866 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 1867 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 1868 1869 // If EmitVAArg fails, we fall back to the LLVM instruction. 1870 if (!ArgPtr) 1871 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 1872 1873 // FIXME Volatility. 1874 return Builder.CreateLoad(ArgPtr); 1875} 1876 1877Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { 1878 return CGF.BuildBlockLiteralTmp(BE); 1879} 1880 1881//===----------------------------------------------------------------------===// 1882// Entry Point into this File 1883//===----------------------------------------------------------------------===// 1884 1885/// EmitScalarExpr - Emit the computation of the specified expression of scalar 1886/// type, ignoring the result. 1887Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 1888 assert(E && !hasAggregateLLVMType(E->getType()) && 1889 "Invalid scalar expression to emit"); 1890 1891 return ScalarExprEmitter(*this, IgnoreResultAssign) 1892 .Visit(const_cast<Expr*>(E)); 1893} 1894 1895/// EmitScalarConversion - Emit a conversion from the specified type to the 1896/// specified destination type, both of which are LLVM scalar types. 1897Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 1898 QualType DstTy) { 1899 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 1900 "Invalid scalar expression to emit"); 1901 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 1902} 1903 1904/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 1905/// type to the specified destination type, where the destination type is an 1906/// LLVM scalar type. 1907Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 1908 QualType SrcTy, 1909 QualType DstTy) { 1910 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 1911 "Invalid complex -> scalar conversion"); 1912 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 1913 DstTy); 1914} 1915 1916Value *CodeGenFunction::EmitShuffleVector(Value* V1, Value *V2, ...) { 1917 assert(V1->getType() == V2->getType() && 1918 "Vector operands must be of the same type"); 1919 unsigned NumElements = 1920 cast<llvm::VectorType>(V1->getType())->getNumElements(); 1921 1922 va_list va; 1923 va_start(va, V2); 1924 1925 llvm::SmallVector<llvm::Constant*, 16> Args; 1926 for (unsigned i = 0; i < NumElements; i++) { 1927 int n = va_arg(va, int); 1928 assert(n >= 0 && n < (int)NumElements * 2 && 1929 "Vector shuffle index out of bounds!"); 1930 Args.push_back(llvm::ConstantInt::get( 1931 llvm::Type::getInt32Ty(VMContext), n)); 1932 } 1933 1934 const char *Name = va_arg(va, const char *); 1935 va_end(va); 1936 1937 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 1938 1939 return Builder.CreateShuffleVector(V1, V2, Mask, Name); 1940} 1941 1942llvm::Value *CodeGenFunction::EmitVector(llvm::Value * const *Vals, 1943 unsigned NumVals, bool isSplat) { 1944 llvm::Value *Vec 1945 = llvm::UndefValue::get(llvm::VectorType::get(Vals[0]->getType(), NumVals)); 1946 1947 for (unsigned i = 0, e = NumVals; i != e; ++i) { 1948 llvm::Value *Val = isSplat ? Vals[0] : Vals[i]; 1949 llvm::Value *Idx = llvm::ConstantInt::get( 1950 llvm::Type::getInt32Ty(VMContext), i); 1951 Vec = Builder.CreateInsertElement(Vec, Val, Idx, "tmp"); 1952 } 1953 1954 return Vec; 1955} 1956