CGExprScalar.cpp revision d888962cff03b543fbe9ac6051ec6addf5b993b4
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(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 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(CastExpr *CE) { 786 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 // FIXME: All casts should have a known kind! 799 //assert(0 && "Unknown cast kind!"); 800 break; 801 802 case CastExpr::CK_BitCast: { 803 Value *Src = Visit(const_cast<Expr*>(E)); 804 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 805 } 806 case CastExpr::CK_NoOp: 807 return Visit(const_cast<Expr*>(E)); 808 809 case CastExpr::CK_BaseToDerived: { 810 const CXXRecordDecl *BaseClassDecl = 811 E->getType()->getCXXRecordDeclForPointerType(); 812 const CXXRecordDecl *DerivedClassDecl = 813 DestTy->getCXXRecordDeclForPointerType(); 814 815 Value *Src = Visit(const_cast<Expr*>(E)); 816 817 bool NullCheckValue = ShouldNullCheckClassCastValue(CE); 818 return CGF.GetAddressOfDerivedClass(Src, BaseClassDecl, DerivedClassDecl, 819 NullCheckValue); 820 } 821 case CastExpr::CK_DerivedToBase: { 822 const RecordType *DerivedClassTy = 823 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 824 CXXRecordDecl *DerivedClassDecl = 825 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 826 827 const RecordType *BaseClassTy = 828 DestTy->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 829 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseClassTy->getDecl()); 830 831 Value *Src = Visit(const_cast<Expr*>(E)); 832 833 bool NullCheckValue = ShouldNullCheckClassCastValue(CE); 834 return CGF.GetAddressOfBaseClass(Src, DerivedClassDecl, BaseClassDecl, 835 NullCheckValue); 836 } 837 case CastExpr::CK_Dynamic: { 838 Value *V = Visit(const_cast<Expr*>(E)); 839 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 840 return CGF.EmitDynamicCast(V, DCE); 841 } 842 case CastExpr::CK_ToUnion: 843 assert(0 && "Should be unreachable!"); 844 break; 845 846 case CastExpr::CK_ArrayToPointerDecay: { 847 assert(E->getType()->isArrayType() && 848 "Array to pointer decay must have array source type!"); 849 850 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 851 852 // Note that VLA pointers are always decayed, so we don't need to do 853 // anything here. 854 if (!E->getType()->isVariableArrayType()) { 855 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 856 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 857 ->getElementType()) && 858 "Expected pointer to array"); 859 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 860 } 861 862 return V; 863 } 864 case CastExpr::CK_FunctionToPointerDecay: 865 return EmitLValue(E).getAddress(); 866 867 case CastExpr::CK_NullToMemberPointer: 868 return CGF.CGM.EmitNullConstant(DestTy); 869 870 case CastExpr::CK_BaseToDerivedMemberPointer: 871 case CastExpr::CK_DerivedToBaseMemberPointer: { 872 Value *Src = Visit(E); 873 874 // See if we need to adjust the pointer. 875 const CXXRecordDecl *BaseDecl = 876 cast<CXXRecordDecl>(E->getType()->getAs<MemberPointerType>()-> 877 getClass()->getAs<RecordType>()->getDecl()); 878 const CXXRecordDecl *DerivedDecl = 879 cast<CXXRecordDecl>(CE->getType()->getAs<MemberPointerType>()-> 880 getClass()->getAs<RecordType>()->getDecl()); 881 if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) 882 std::swap(DerivedDecl, BaseDecl); 883 884 llvm::Constant *Adj = CGF.CGM.GetCXXBaseClassOffset(DerivedDecl, BaseDecl); 885 if (Adj) { 886 if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) 887 Src = Builder.CreateSub(Src, Adj, "adj"); 888 else 889 Src = Builder.CreateAdd(Src, Adj, "adj"); 890 } 891 return Src; 892 } 893 894 case CastExpr::CK_UserDefinedConversion: 895 case CastExpr::CK_ConstructorConversion: 896 assert(0 && "Should be unreachable!"); 897 break; 898 899 case CastExpr::CK_IntegralToPointer: { 900 Value *Src = Visit(const_cast<Expr*>(E)); 901 902 // First, convert to the correct width so that we control the kind of 903 // extension. 904 const llvm::Type *MiddleTy = 905 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 906 bool InputSigned = E->getType()->isSignedIntegerType(); 907 llvm::Value* IntResult = 908 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 909 910 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 911 } 912 case CastExpr::CK_PointerToIntegral: { 913 Value *Src = Visit(const_cast<Expr*>(E)); 914 return Builder.CreatePtrToInt(Src, ConvertType(DestTy)); 915 } 916 case CastExpr::CK_ToVoid: { 917 CGF.EmitAnyExpr(E, 0, false, true); 918 return 0; 919 } 920 case CastExpr::CK_VectorSplat: { 921 const llvm::Type *DstTy = ConvertType(DestTy); 922 Value *Elt = Visit(const_cast<Expr*>(E)); 923 924 // Insert the element in element zero of an undef vector 925 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 926 llvm::Value *Idx = 927 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0); 928 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 929 930 // Splat the element across to all elements 931 llvm::SmallVector<llvm::Constant*, 16> Args; 932 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 933 for (unsigned i = 0; i < NumElements; i++) 934 Args.push_back(llvm::ConstantInt::get( 935 llvm::Type::getInt32Ty(VMContext), 0)); 936 937 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 938 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 939 return Yay; 940 } 941 case CastExpr::CK_IntegralCast: 942 case CastExpr::CK_IntegralToFloating: 943 case CastExpr::CK_FloatingToIntegral: 944 case CastExpr::CK_FloatingCast: 945 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 946 947 case CastExpr::CK_MemberPointerToBoolean: { 948 const MemberPointerType* T = E->getType()->getAs<MemberPointerType>(); 949 950 if (T->getPointeeType()->isFunctionType()) { 951 // We have a member function pointer. 952 llvm::Value *Ptr = CGF.CreateTempAlloca(ConvertType(E->getType())); 953 954 CGF.EmitAggExpr(E, Ptr, /*VolatileDest=*/false); 955 956 // Get the pointer. 957 llvm::Value *FuncPtr = Builder.CreateStructGEP(Ptr, 0, "src.ptr"); 958 FuncPtr = Builder.CreateLoad(FuncPtr); 959 960 llvm::Value *IsNotNull = 961 Builder.CreateICmpNE(FuncPtr, 962 llvm::Constant::getNullValue(FuncPtr->getType()), 963 "tobool"); 964 965 return IsNotNull; 966 } 967 968 // We have a regular member pointer. 969 Value *Ptr = Visit(const_cast<Expr*>(E)); 970 llvm::Value *IsNotNull = 971 Builder.CreateICmpNE(Ptr, CGF.CGM.EmitNullConstant(E->getType()), 972 "tobool"); 973 return IsNotNull; 974 } 975 } 976 977 // Handle cases where the source is an non-complex type. 978 979 if (!CGF.hasAggregateLLVMType(E->getType())) { 980 Value *Src = Visit(const_cast<Expr*>(E)); 981 982 // Use EmitScalarConversion to perform the conversion. 983 return EmitScalarConversion(Src, E->getType(), DestTy); 984 } 985 986 if (E->getType()->isAnyComplexType()) { 987 // Handle cases where the source is a complex type. 988 bool IgnoreImag = true; 989 bool IgnoreImagAssign = true; 990 bool IgnoreReal = IgnoreResultAssign; 991 bool IgnoreRealAssign = IgnoreResultAssign; 992 if (DestTy->isBooleanType()) 993 IgnoreImagAssign = IgnoreImag = false; 994 else if (DestTy->isVoidType()) { 995 IgnoreReal = IgnoreImag = false; 996 IgnoreRealAssign = IgnoreImagAssign = true; 997 } 998 CodeGenFunction::ComplexPairTy V 999 = CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign, 1000 IgnoreImagAssign); 1001 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 1002 } 1003 1004 // Okay, this is a cast from an aggregate. It must be a cast to void. Just 1005 // evaluate the result and return. 1006 CGF.EmitAggExpr(E, 0, false, true); 1007 return 0; 1008} 1009 1010Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 1011 return CGF.EmitCompoundStmt(*E->getSubStmt(), 1012 !E->getType()->isVoidType()).getScalarVal(); 1013} 1014 1015Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 1016 llvm::Value *V = CGF.GetAddrOfBlockDecl(E); 1017 if (E->getType().isObjCGCWeak()) 1018 return CGF.CGM.getObjCRuntime().EmitObjCWeakRead(CGF, V); 1019 return Builder.CreateLoad(V, false, "tmp"); 1020} 1021 1022//===----------------------------------------------------------------------===// 1023// Unary Operators 1024//===----------------------------------------------------------------------===// 1025 1026Value *ScalarExprEmitter::VisitPrePostIncDec(const UnaryOperator *E, 1027 bool isInc, bool isPre) { 1028 LValue LV = EmitLValue(E->getSubExpr()); 1029 QualType ValTy = E->getSubExpr()->getType(); 1030 Value *InVal = CGF.EmitLoadOfLValue(LV, ValTy).getScalarVal(); 1031 1032 llvm::LLVMContext &VMContext = CGF.getLLVMContext(); 1033 1034 int AmountVal = isInc ? 1 : -1; 1035 1036 if (ValTy->isPointerType() && 1037 ValTy->getAs<PointerType>()->isVariableArrayType()) { 1038 // The amount of the addition/subtraction needs to account for the VLA size 1039 CGF.ErrorUnsupported(E, "VLA pointer inc/dec"); 1040 } 1041 1042 Value *NextVal; 1043 if (const llvm::PointerType *PT = 1044 dyn_cast<llvm::PointerType>(InVal->getType())) { 1045 llvm::Constant *Inc = 1046 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), AmountVal); 1047 if (!isa<llvm::FunctionType>(PT->getElementType())) { 1048 QualType PTEE = ValTy->getPointeeType(); 1049 if (const ObjCInterfaceType *OIT = 1050 dyn_cast<ObjCInterfaceType>(PTEE)) { 1051 // Handle interface types, which are not represented with a concrete type. 1052 int size = CGF.getContext().getTypeSize(OIT) / 8; 1053 if (!isInc) 1054 size = -size; 1055 Inc = llvm::ConstantInt::get(Inc->getType(), size); 1056 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1057 InVal = Builder.CreateBitCast(InVal, i8Ty); 1058 NextVal = Builder.CreateGEP(InVal, Inc, "add.ptr"); 1059 llvm::Value *lhs = LV.getAddress(); 1060 lhs = Builder.CreateBitCast(lhs, llvm::PointerType::getUnqual(i8Ty)); 1061 LV = LValue::MakeAddr(lhs, CGF.MakeQualifiers(ValTy)); 1062 } else 1063 NextVal = Builder.CreateInBoundsGEP(InVal, Inc, "ptrincdec"); 1064 } else { 1065 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1066 NextVal = Builder.CreateBitCast(InVal, i8Ty, "tmp"); 1067 NextVal = Builder.CreateGEP(NextVal, Inc, "ptrincdec"); 1068 NextVal = Builder.CreateBitCast(NextVal, InVal->getType()); 1069 } 1070 } else if (InVal->getType() == llvm::Type::getInt1Ty(VMContext) && isInc) { 1071 // Bool++ is an interesting case, due to promotion rules, we get: 1072 // Bool++ -> Bool = Bool+1 -> Bool = (int)Bool+1 -> 1073 // Bool = ((int)Bool+1) != 0 1074 // An interesting aspect of this is that increment is always true. 1075 // Decrement does not have this property. 1076 NextVal = llvm::ConstantInt::getTrue(VMContext); 1077 } else if (isa<llvm::IntegerType>(InVal->getType())) { 1078 NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); 1079 1080 // Signed integer overflow is undefined behavior. 1081 if (ValTy->isSignedIntegerType()) 1082 NextVal = Builder.CreateNSWAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1083 else 1084 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1085 } else { 1086 // Add the inc/dec to the real part. 1087 if (InVal->getType()->isFloatTy()) 1088 NextVal = 1089 llvm::ConstantFP::get(VMContext, 1090 llvm::APFloat(static_cast<float>(AmountVal))); 1091 else if (InVal->getType()->isDoubleTy()) 1092 NextVal = 1093 llvm::ConstantFP::get(VMContext, 1094 llvm::APFloat(static_cast<double>(AmountVal))); 1095 else { 1096 llvm::APFloat F(static_cast<float>(AmountVal)); 1097 bool ignored; 1098 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, 1099 &ignored); 1100 NextVal = llvm::ConstantFP::get(VMContext, F); 1101 } 1102 NextVal = Builder.CreateFAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1103 } 1104 1105 // Store the updated result through the lvalue. 1106 if (LV.isBitfield()) 1107 CGF.EmitStoreThroughBitfieldLValue(RValue::get(NextVal), LV, ValTy, 1108 &NextVal); 1109 else 1110 CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV, ValTy); 1111 1112 // If this is a postinc, return the value read from memory, otherwise use the 1113 // updated value. 1114 return isPre ? NextVal : InVal; 1115} 1116 1117 1118Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1119 TestAndClearIgnoreResultAssign(); 1120 Value *Op = Visit(E->getSubExpr()); 1121 if (Op->getType()->isFPOrFPVector()) 1122 return Builder.CreateFNeg(Op, "neg"); 1123 return Builder.CreateNeg(Op, "neg"); 1124} 1125 1126Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1127 TestAndClearIgnoreResultAssign(); 1128 Value *Op = Visit(E->getSubExpr()); 1129 return Builder.CreateNot(Op, "neg"); 1130} 1131 1132Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1133 // Compare operand to zero. 1134 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1135 1136 // Invert value. 1137 // TODO: Could dynamically modify easy computations here. For example, if 1138 // the operand is an icmp ne, turn into icmp eq. 1139 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1140 1141 // ZExt result to the expr type. 1142 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1143} 1144 1145/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of 1146/// argument of the sizeof expression as an integer. 1147Value * 1148ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { 1149 QualType TypeToSize = E->getTypeOfArgument(); 1150 if (E->isSizeOf()) { 1151 if (const VariableArrayType *VAT = 1152 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1153 if (E->isArgumentType()) { 1154 // sizeof(type) - make sure to emit the VLA size. 1155 CGF.EmitVLASize(TypeToSize); 1156 } else { 1157 // C99 6.5.3.4p2: If the argument is an expression of type 1158 // VLA, it is evaluated. 1159 CGF.EmitAnyExpr(E->getArgumentExpr()); 1160 } 1161 1162 return CGF.GetVLASize(VAT); 1163 } 1164 } 1165 1166 // If this isn't sizeof(vla), the result must be constant; use the constant 1167 // folding logic so we don't have to duplicate it here. 1168 Expr::EvalResult Result; 1169 E->Evaluate(Result, CGF.getContext()); 1170 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 1171} 1172 1173Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1174 Expr *Op = E->getSubExpr(); 1175 if (Op->getType()->isAnyComplexType()) 1176 return CGF.EmitComplexExpr(Op, false, true, false, true).first; 1177 return Visit(Op); 1178} 1179Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1180 Expr *Op = E->getSubExpr(); 1181 if (Op->getType()->isAnyComplexType()) 1182 return CGF.EmitComplexExpr(Op, true, false, true, false).second; 1183 1184 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1185 // effects are evaluated, but not the actual value. 1186 if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) 1187 CGF.EmitLValue(Op); 1188 else 1189 CGF.EmitScalarExpr(Op, true); 1190 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1191} 1192 1193Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) { 1194 Value* ResultAsPtr = EmitLValue(E->getSubExpr()).getAddress(); 1195 const llvm::Type* ResultType = ConvertType(E->getType()); 1196 return Builder.CreatePtrToInt(ResultAsPtr, ResultType, "offsetof"); 1197} 1198 1199//===----------------------------------------------------------------------===// 1200// Binary Operators 1201//===----------------------------------------------------------------------===// 1202 1203BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1204 TestAndClearIgnoreResultAssign(); 1205 BinOpInfo Result; 1206 Result.LHS = Visit(E->getLHS()); 1207 Result.RHS = Visit(E->getRHS()); 1208 Result.Ty = E->getType(); 1209 Result.E = E; 1210 return Result; 1211} 1212 1213Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 1214 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 1215 bool Ignore = TestAndClearIgnoreResultAssign(); 1216 QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType(); 1217 1218 BinOpInfo OpInfo; 1219 1220 if (E->getComputationResultType()->isAnyComplexType()) { 1221 // This needs to go through the complex expression emitter, but it's a tad 1222 // complicated to do that... I'm leaving it out for now. (Note that we do 1223 // actually need the imaginary part of the RHS for multiplication and 1224 // division.) 1225 CGF.ErrorUnsupported(E, "complex compound assignment"); 1226 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 1227 } 1228 1229 // Emit the RHS first. __block variables need to have the rhs evaluated 1230 // first, plus this should improve codegen a little. 1231 OpInfo.RHS = Visit(E->getRHS()); 1232 OpInfo.Ty = E->getComputationResultType(); 1233 OpInfo.E = E; 1234 // Load/convert the LHS. 1235 LValue LHSLV = EmitLValue(E->getLHS()); 1236 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 1237 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 1238 E->getComputationLHSType()); 1239 1240 // Expand the binary operator. 1241 Value *Result = (this->*Func)(OpInfo); 1242 1243 // Convert the result back to the LHS type. 1244 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 1245 1246 // Store the result value into the LHS lvalue. Bit-fields are handled 1247 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 1248 // 'An assignment expression has the value of the left operand after the 1249 // assignment...'. 1250 if (LHSLV.isBitfield()) { 1251 if (!LHSLV.isVolatileQualified()) { 1252 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, 1253 &Result); 1254 return Result; 1255 } else 1256 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy); 1257 } else 1258 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); 1259 if (Ignore) 1260 return 0; 1261 return EmitLoadOfLValue(LHSLV, E->getType()); 1262} 1263 1264 1265Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 1266 if (Ops.LHS->getType()->isFPOrFPVector()) 1267 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 1268 else if (Ops.Ty->isUnsignedIntegerType()) 1269 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 1270 else 1271 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 1272} 1273 1274Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 1275 // Rem in C can't be a floating point type: C99 6.5.5p2. 1276 if (Ops.Ty->isUnsignedIntegerType()) 1277 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 1278 else 1279 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 1280} 1281 1282Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 1283 unsigned IID; 1284 unsigned OpID = 0; 1285 1286 switch (Ops.E->getOpcode()) { 1287 case BinaryOperator::Add: 1288 case BinaryOperator::AddAssign: 1289 OpID = 1; 1290 IID = llvm::Intrinsic::sadd_with_overflow; 1291 break; 1292 case BinaryOperator::Sub: 1293 case BinaryOperator::SubAssign: 1294 OpID = 2; 1295 IID = llvm::Intrinsic::ssub_with_overflow; 1296 break; 1297 case BinaryOperator::Mul: 1298 case BinaryOperator::MulAssign: 1299 OpID = 3; 1300 IID = llvm::Intrinsic::smul_with_overflow; 1301 break; 1302 default: 1303 assert(false && "Unsupported operation for overflow detection"); 1304 IID = 0; 1305 } 1306 OpID <<= 1; 1307 OpID |= 1; 1308 1309 const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1310 1311 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1); 1312 1313 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1314 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1315 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1316 1317 // Branch in case of overflow. 1318 llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); 1319 llvm::BasicBlock *overflowBB = 1320 CGF.createBasicBlock("overflow", CGF.CurFn); 1321 llvm::BasicBlock *continueBB = 1322 CGF.createBasicBlock("overflow.continue", CGF.CurFn); 1323 1324 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1325 1326 // Handle overflow 1327 1328 Builder.SetInsertPoint(overflowBB); 1329 1330 // Handler is: 1331 // long long *__overflow_handler)(long long a, long long b, char op, 1332 // char width) 1333 std::vector<const llvm::Type*> handerArgTypes; 1334 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1335 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1336 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1337 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1338 llvm::FunctionType *handlerTy = llvm::FunctionType::get( 1339 llvm::Type::getInt64Ty(VMContext), handerArgTypes, false); 1340 llvm::Value *handlerFunction = 1341 CGF.CGM.getModule().getOrInsertGlobal("__overflow_handler", 1342 llvm::PointerType::getUnqual(handlerTy)); 1343 handlerFunction = Builder.CreateLoad(handlerFunction); 1344 1345 llvm::Value *handlerResult = Builder.CreateCall4(handlerFunction, 1346 Builder.CreateSExt(Ops.LHS, llvm::Type::getInt64Ty(VMContext)), 1347 Builder.CreateSExt(Ops.RHS, llvm::Type::getInt64Ty(VMContext)), 1348 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), OpID), 1349 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), 1350 cast<llvm::IntegerType>(opTy)->getBitWidth())); 1351 1352 handlerResult = Builder.CreateTrunc(handlerResult, opTy); 1353 1354 Builder.CreateBr(continueBB); 1355 1356 // Set up the continuation 1357 Builder.SetInsertPoint(continueBB); 1358 // Get the correct result 1359 llvm::PHINode *phi = Builder.CreatePHI(opTy); 1360 phi->reserveOperandSpace(2); 1361 phi->addIncoming(result, initialBB); 1362 phi->addIncoming(handlerResult, overflowBB); 1363 1364 return phi; 1365} 1366 1367Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 1368 if (!Ops.Ty->isAnyPointerType()) { 1369 if (CGF.getContext().getLangOptions().OverflowChecking && 1370 Ops.Ty->isSignedIntegerType()) 1371 return EmitOverflowCheckedBinOp(Ops); 1372 1373 if (Ops.LHS->getType()->isFPOrFPVector()) 1374 return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add"); 1375 1376 // Signed integer overflow is undefined behavior. 1377 if (Ops.Ty->isSignedIntegerType()) 1378 return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add"); 1379 1380 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1381 } 1382 1383 if (Ops.Ty->isPointerType() && 1384 Ops.Ty->getAs<PointerType>()->isVariableArrayType()) { 1385 // The amount of the addition needs to account for the VLA size 1386 CGF.ErrorUnsupported(Ops.E, "VLA pointer addition"); 1387 } 1388 Value *Ptr, *Idx; 1389 Expr *IdxExp; 1390 const PointerType *PT = Ops.E->getLHS()->getType()->getAs<PointerType>(); 1391 const ObjCObjectPointerType *OPT = 1392 Ops.E->getLHS()->getType()->getAs<ObjCObjectPointerType>(); 1393 if (PT || OPT) { 1394 Ptr = Ops.LHS; 1395 Idx = Ops.RHS; 1396 IdxExp = Ops.E->getRHS(); 1397 } else { // int + pointer 1398 PT = Ops.E->getRHS()->getType()->getAs<PointerType>(); 1399 OPT = Ops.E->getRHS()->getType()->getAs<ObjCObjectPointerType>(); 1400 assert((PT || OPT) && "Invalid add expr"); 1401 Ptr = Ops.RHS; 1402 Idx = Ops.LHS; 1403 IdxExp = Ops.E->getLHS(); 1404 } 1405 1406 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1407 if (Width < CGF.LLVMPointerWidth) { 1408 // Zero or sign extend the pointer value based on whether the index is 1409 // signed or not. 1410 const llvm::Type *IdxType = 1411 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1412 if (IdxExp->getType()->isSignedIntegerType()) 1413 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1414 else 1415 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1416 } 1417 const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType(); 1418 // Handle interface types, which are not represented with a concrete type. 1419 if (const ObjCInterfaceType *OIT = dyn_cast<ObjCInterfaceType>(ElementType)) { 1420 llvm::Value *InterfaceSize = 1421 llvm::ConstantInt::get(Idx->getType(), 1422 CGF.getContext().getTypeSize(OIT) / 8); 1423 Idx = Builder.CreateMul(Idx, InterfaceSize); 1424 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1425 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1426 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1427 return Builder.CreateBitCast(Res, Ptr->getType()); 1428 } 1429 1430 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 1431 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 1432 // future proof. 1433 if (ElementType->isVoidType() || ElementType->isFunctionType()) { 1434 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1435 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1436 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1437 return Builder.CreateBitCast(Res, Ptr->getType()); 1438 } 1439 1440 return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr"); 1441} 1442 1443Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 1444 if (!isa<llvm::PointerType>(Ops.LHS->getType())) { 1445 if (CGF.getContext().getLangOptions().OverflowChecking 1446 && Ops.Ty->isSignedIntegerType()) 1447 return EmitOverflowCheckedBinOp(Ops); 1448 1449 if (Ops.LHS->getType()->isFPOrFPVector()) 1450 return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub"); 1451 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1452 } 1453 1454 if (Ops.E->getLHS()->getType()->isPointerType() && 1455 Ops.E->getLHS()->getType()->getAs<PointerType>()->isVariableArrayType()) { 1456 // The amount of the addition needs to account for the VLA size for 1457 // ptr-int 1458 // The amount of the division needs to account for the VLA size for 1459 // ptr-ptr. 1460 CGF.ErrorUnsupported(Ops.E, "VLA pointer subtraction"); 1461 } 1462 1463 const QualType LHSType = Ops.E->getLHS()->getType(); 1464 const QualType LHSElementType = LHSType->getPointeeType(); 1465 if (!isa<llvm::PointerType>(Ops.RHS->getType())) { 1466 // pointer - int 1467 Value *Idx = Ops.RHS; 1468 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1469 if (Width < CGF.LLVMPointerWidth) { 1470 // Zero or sign extend the pointer value based on whether the index is 1471 // signed or not. 1472 const llvm::Type *IdxType = 1473 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1474 if (Ops.E->getRHS()->getType()->isSignedIntegerType()) 1475 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1476 else 1477 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1478 } 1479 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); 1480 1481 // Handle interface types, which are not represented with a concrete type. 1482 if (const ObjCInterfaceType *OIT = 1483 dyn_cast<ObjCInterfaceType>(LHSElementType)) { 1484 llvm::Value *InterfaceSize = 1485 llvm::ConstantInt::get(Idx->getType(), 1486 CGF.getContext().getTypeSize(OIT) / 8); 1487 Idx = Builder.CreateMul(Idx, InterfaceSize); 1488 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1489 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1490 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr"); 1491 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1492 } 1493 1494 // Explicitly handle GNU void* and function pointer arithmetic 1495 // extensions. The GNU void* casts amount to no-ops since our void* type is 1496 // i8*, but this is future proof. 1497 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1498 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1499 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1500 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); 1501 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1502 } 1503 1504 return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr"); 1505 } else { 1506 // pointer - pointer 1507 Value *LHS = Ops.LHS; 1508 Value *RHS = Ops.RHS; 1509 1510 uint64_t ElementSize; 1511 1512 // Handle GCC extension for pointer arithmetic on void* and function pointer 1513 // types. 1514 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1515 ElementSize = 1; 1516 } else { 1517 ElementSize = CGF.getContext().getTypeSize(LHSElementType) / 8; 1518 } 1519 1520 const llvm::Type *ResultType = ConvertType(Ops.Ty); 1521 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 1522 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 1523 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 1524 1525 // Optimize out the shift for element size of 1. 1526 if (ElementSize == 1) 1527 return BytesBetween; 1528 1529 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 1530 // pointer difference in C is only defined in the case where both operands 1531 // are pointing to elements of an array. 1532 Value *BytesPerElt = llvm::ConstantInt::get(ResultType, ElementSize); 1533 return Builder.CreateExactSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 1534 } 1535} 1536 1537Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 1538 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1539 // RHS to the same size as the LHS. 1540 Value *RHS = Ops.RHS; 1541 if (Ops.LHS->getType() != RHS->getType()) 1542 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1543 1544 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 1545} 1546 1547Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 1548 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1549 // RHS to the same size as the LHS. 1550 Value *RHS = Ops.RHS; 1551 if (Ops.LHS->getType() != RHS->getType()) 1552 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1553 1554 if (Ops.Ty->isUnsignedIntegerType()) 1555 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 1556 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 1557} 1558 1559Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 1560 unsigned SICmpOpc, unsigned FCmpOpc) { 1561 TestAndClearIgnoreResultAssign(); 1562 Value *Result; 1563 QualType LHSTy = E->getLHS()->getType(); 1564 if (!LHSTy->isAnyComplexType()) { 1565 Value *LHS = Visit(E->getLHS()); 1566 Value *RHS = Visit(E->getRHS()); 1567 1568 if (LHS->getType()->isFPOrFPVector()) { 1569 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 1570 LHS, RHS, "cmp"); 1571 } else if (LHSTy->isSignedIntegerType()) { 1572 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 1573 LHS, RHS, "cmp"); 1574 } else { 1575 // Unsigned integers and pointers. 1576 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1577 LHS, RHS, "cmp"); 1578 } 1579 1580 // If this is a vector comparison, sign extend the result to the appropriate 1581 // vector integer type and return it (don't convert to bool). 1582 if (LHSTy->isVectorType()) 1583 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 1584 1585 } else { 1586 // Complex Comparison: can only be an equality comparison. 1587 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 1588 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 1589 1590 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 1591 1592 Value *ResultR, *ResultI; 1593 if (CETy->isRealFloatingType()) { 1594 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1595 LHS.first, RHS.first, "cmp.r"); 1596 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1597 LHS.second, RHS.second, "cmp.i"); 1598 } else { 1599 // Complex comparisons can only be equality comparisons. As such, signed 1600 // and unsigned opcodes are the same. 1601 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1602 LHS.first, RHS.first, "cmp.r"); 1603 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1604 LHS.second, RHS.second, "cmp.i"); 1605 } 1606 1607 if (E->getOpcode() == BinaryOperator::EQ) { 1608 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 1609 } else { 1610 assert(E->getOpcode() == BinaryOperator::NE && 1611 "Complex comparison other than == or != ?"); 1612 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 1613 } 1614 } 1615 1616 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 1617} 1618 1619Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 1620 bool Ignore = TestAndClearIgnoreResultAssign(); 1621 1622 // __block variables need to have the rhs evaluated first, plus this should 1623 // improve codegen just a little. 1624 Value *RHS = Visit(E->getRHS()); 1625 LValue LHS = EmitLValue(E->getLHS()); 1626 1627 // Store the value into the LHS. Bit-fields are handled specially 1628 // because the result is altered by the store, i.e., [C99 6.5.16p1] 1629 // 'An assignment expression has the value of the left operand after 1630 // the assignment...'. 1631 if (LHS.isBitfield()) { 1632 if (!LHS.isVolatileQualified()) { 1633 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), 1634 &RHS); 1635 return RHS; 1636 } else 1637 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType()); 1638 } else 1639 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 1640 if (Ignore) 1641 return 0; 1642 return EmitLoadOfLValue(LHS, E->getType()); 1643} 1644 1645Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 1646 const llvm::Type *ResTy = ConvertType(E->getType()); 1647 1648 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 1649 // If we have 1 && X, just emit X without inserting the control flow. 1650 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1651 if (Cond == 1) { // If we have 1 && X, just emit X. 1652 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1653 // ZExt result to int or bool. 1654 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 1655 } 1656 1657 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 1658 if (!CGF.ContainsLabel(E->getRHS())) 1659 return llvm::Constant::getNullValue(ResTy); 1660 } 1661 1662 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 1663 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 1664 1665 // Branch on the LHS first. If it is false, go to the failure (cont) block. 1666 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 1667 1668 // Any edges into the ContBlock are now from an (indeterminate number of) 1669 // edges from this first condition. All of these values will be false. Start 1670 // setting up the PHI node in the Cont Block for this. 1671 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1672 "", ContBlock); 1673 PN->reserveOperandSpace(2); // Normal case, two inputs. 1674 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1675 PI != PE; ++PI) 1676 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 1677 1678 CGF.StartConditionalBranch(); 1679 CGF.EmitBlock(RHSBlock); 1680 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1681 CGF.FinishConditionalBranch(); 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, "land.ext"); 1693} 1694 1695Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 1696 const llvm::Type *ResTy = ConvertType(E->getType()); 1697 1698 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 1699 // If we have 0 || X, just emit X without inserting the control flow. 1700 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1701 if (Cond == -1) { // If we have 0 || X, just emit X. 1702 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1703 // ZExt result to int or bool. 1704 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 1705 } 1706 1707 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 1708 if (!CGF.ContainsLabel(E->getRHS())) 1709 return llvm::ConstantInt::get(ResTy, 1); 1710 } 1711 1712 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 1713 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 1714 1715 // Branch on the LHS first. If it is true, go to the success (cont) block. 1716 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 1717 1718 // Any edges into the ContBlock are now from an (indeterminate number of) 1719 // edges from this first condition. All of these values will be true. Start 1720 // setting up the PHI node in the Cont Block for this. 1721 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1722 "", ContBlock); 1723 PN->reserveOperandSpace(2); // Normal case, two inputs. 1724 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1725 PI != PE; ++PI) 1726 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 1727 1728 CGF.StartConditionalBranch(); 1729 1730 // Emit the RHS condition as a bool value. 1731 CGF.EmitBlock(RHSBlock); 1732 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1733 1734 CGF.FinishConditionalBranch(); 1735 1736 // Reaquire the RHS block, as there may be subblocks inserted. 1737 RHSBlock = Builder.GetInsertBlock(); 1738 1739 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1740 // into the phi node for the edge with the value of RHSCond. 1741 CGF.EmitBlock(ContBlock); 1742 PN->addIncoming(RHSCond, RHSBlock); 1743 1744 // ZExt result to int. 1745 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 1746} 1747 1748Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 1749 CGF.EmitStmt(E->getLHS()); 1750 CGF.EnsureInsertPoint(); 1751 return Visit(E->getRHS()); 1752} 1753 1754//===----------------------------------------------------------------------===// 1755// Other Operators 1756//===----------------------------------------------------------------------===// 1757 1758/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 1759/// expression is cheap enough and side-effect-free enough to evaluate 1760/// unconditionally instead of conditionally. This is used to convert control 1761/// flow into selects in some cases. 1762static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 1763 CodeGenFunction &CGF) { 1764 if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) 1765 return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr(), CGF); 1766 1767 // TODO: Allow anything we can constant fold to an integer or fp constant. 1768 if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || 1769 isa<FloatingLiteral>(E)) 1770 return true; 1771 1772 // Non-volatile automatic variables too, to get "cond ? X : Y" where 1773 // X and Y are local variables. 1774 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 1775 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 1776 if (VD->hasLocalStorage() && !(CGF.getContext() 1777 .getCanonicalType(VD->getType()) 1778 .isVolatileQualified())) 1779 return true; 1780 1781 return false; 1782} 1783 1784 1785Value *ScalarExprEmitter:: 1786VisitConditionalOperator(const ConditionalOperator *E) { 1787 TestAndClearIgnoreResultAssign(); 1788 // If the condition constant folds and can be elided, try to avoid emitting 1789 // the condition and the dead arm. 1790 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ 1791 Expr *Live = E->getLHS(), *Dead = E->getRHS(); 1792 if (Cond == -1) 1793 std::swap(Live, Dead); 1794 1795 // If the dead side doesn't have labels we need, and if the Live side isn't 1796 // the gnu missing ?: extension (which we could handle, but don't bother 1797 // to), just emit the Live part. 1798 if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part 1799 Live) // Live part isn't missing. 1800 return Visit(Live); 1801 } 1802 1803 1804 // If this is a really simple expression (like x ? 4 : 5), emit this as a 1805 // select instead of as control flow. We can only do this if it is cheap and 1806 // safe to evaluate the LHS and RHS unconditionally. 1807 if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS(), 1808 CGF) && 1809 isCheapEnoughToEvaluateUnconditionally(E->getRHS(), CGF)) { 1810 llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); 1811 llvm::Value *LHS = Visit(E->getLHS()); 1812 llvm::Value *RHS = Visit(E->getRHS()); 1813 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 1814 } 1815 1816 1817 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 1818 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 1819 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 1820 Value *CondVal = 0; 1821 1822 // If we don't have the GNU missing condition extension, emit a branch on bool 1823 // the normal way. 1824 if (E->getLHS()) { 1825 // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for 1826 // the branch on bool. 1827 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); 1828 } else { 1829 // Otherwise, for the ?: extension, evaluate the conditional and then 1830 // convert it to bool the hard way. We do this explicitly because we need 1831 // the unconverted value for the missing middle value of the ?:. 1832 CondVal = CGF.EmitScalarExpr(E->getCond()); 1833 1834 // In some cases, EmitScalarConversion will delete the "CondVal" expression 1835 // if there are no extra uses (an optimization). Inhibit this by making an 1836 // extra dead use, because we're going to add a use of CondVal later. We 1837 // don't use the builder for this, because we don't want it to get optimized 1838 // away. This leaves dead code, but the ?: extension isn't common. 1839 new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", 1840 Builder.GetInsertBlock()); 1841 1842 Value *CondBoolVal = 1843 CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 1844 CGF.getContext().BoolTy); 1845 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 1846 } 1847 1848 CGF.StartConditionalBranch(); 1849 CGF.EmitBlock(LHSBlock); 1850 1851 // Handle the GNU extension for missing LHS. 1852 Value *LHS; 1853 if (E->getLHS()) 1854 LHS = Visit(E->getLHS()); 1855 else // Perform promotions, to handle cases like "short ?: int" 1856 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); 1857 1858 CGF.FinishConditionalBranch(); 1859 LHSBlock = Builder.GetInsertBlock(); 1860 CGF.EmitBranch(ContBlock); 1861 1862 CGF.StartConditionalBranch(); 1863 CGF.EmitBlock(RHSBlock); 1864 1865 Value *RHS = Visit(E->getRHS()); 1866 CGF.FinishConditionalBranch(); 1867 RHSBlock = Builder.GetInsertBlock(); 1868 CGF.EmitBranch(ContBlock); 1869 1870 CGF.EmitBlock(ContBlock); 1871 1872 if (!LHS || !RHS) { 1873 assert(E->getType()->isVoidType() && "Non-void value should have a value"); 1874 return 0; 1875 } 1876 1877 // Create a PHI node for the real part. 1878 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 1879 PN->reserveOperandSpace(2); 1880 PN->addIncoming(LHS, LHSBlock); 1881 PN->addIncoming(RHS, RHSBlock); 1882 return PN; 1883} 1884 1885Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 1886 return Visit(E->getChosenSubExpr(CGF.getContext())); 1887} 1888 1889Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 1890 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 1891 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 1892 1893 // If EmitVAArg fails, we fall back to the LLVM instruction. 1894 if (!ArgPtr) 1895 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 1896 1897 // FIXME Volatility. 1898 return Builder.CreateLoad(ArgPtr); 1899} 1900 1901Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { 1902 return CGF.BuildBlockLiteralTmp(BE); 1903} 1904 1905//===----------------------------------------------------------------------===// 1906// Entry Point into this File 1907//===----------------------------------------------------------------------===// 1908 1909/// EmitScalarExpr - Emit the computation of the specified expression of scalar 1910/// type, ignoring the result. 1911Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 1912 assert(E && !hasAggregateLLVMType(E->getType()) && 1913 "Invalid scalar expression to emit"); 1914 1915 return ScalarExprEmitter(*this, IgnoreResultAssign) 1916 .Visit(const_cast<Expr*>(E)); 1917} 1918 1919/// EmitScalarConversion - Emit a conversion from the specified type to the 1920/// specified destination type, both of which are LLVM scalar types. 1921Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 1922 QualType DstTy) { 1923 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 1924 "Invalid scalar expression to emit"); 1925 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 1926} 1927 1928/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 1929/// type to the specified destination type, where the destination type is an 1930/// LLVM scalar type. 1931Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 1932 QualType SrcTy, 1933 QualType DstTy) { 1934 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 1935 "Invalid complex -> scalar conversion"); 1936 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 1937 DstTy); 1938} 1939 1940Value *CodeGenFunction::EmitShuffleVector(Value* V1, Value *V2, ...) { 1941 assert(V1->getType() == V2->getType() && 1942 "Vector operands must be of the same type"); 1943 unsigned NumElements = 1944 cast<llvm::VectorType>(V1->getType())->getNumElements(); 1945 1946 va_list va; 1947 va_start(va, V2); 1948 1949 llvm::SmallVector<llvm::Constant*, 16> Args; 1950 for (unsigned i = 0; i < NumElements; i++) { 1951 int n = va_arg(va, int); 1952 assert(n >= 0 && n < (int)NumElements * 2 && 1953 "Vector shuffle index out of bounds!"); 1954 Args.push_back(llvm::ConstantInt::get( 1955 llvm::Type::getInt32Ty(VMContext), n)); 1956 } 1957 1958 const char *Name = va_arg(va, const char *); 1959 va_end(va); 1960 1961 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 1962 1963 return Builder.CreateShuffleVector(V1, V2, Mask, Name); 1964} 1965 1966llvm::Value *CodeGenFunction::EmitVector(llvm::Value * const *Vals, 1967 unsigned NumVals, bool isSplat) { 1968 llvm::Value *Vec 1969 = llvm::UndefValue::get(llvm::VectorType::get(Vals[0]->getType(), NumVals)); 1970 1971 for (unsigned i = 0, e = NumVals; i != e; ++i) { 1972 llvm::Value *Val = isSplat ? Vals[0] : Vals[i]; 1973 llvm::Value *Idx = llvm::ConstantInt::get( 1974 llvm::Type::getInt32Ty(VMContext), i); 1975 Vec = Builder.CreateInsertElement(Vec, Val, Idx, "tmp"); 1976 } 1977 1978 return Vec; 1979} 1980