CGExprScalar.cpp revision 34a2d384c745ebc39cae45dc1c0c4a6a7012e09b
1//===--- CGExprScalar.cpp - Emit LLVM Code for Scalar Exprs ---------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This contains code to emit Expr nodes with scalar LLVM types as LLVM code. 11// 12//===----------------------------------------------------------------------===// 13 14#include "CodeGenFunction.h" 15#include "CGObjCRuntime.h" 16#include "CodeGenModule.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/AST/DeclObjC.h" 19#include "clang/AST/RecordLayout.h" 20#include "clang/AST/StmtVisitor.h" 21#include "clang/Basic/TargetInfo.h" 22#include "llvm/Constants.h" 23#include "llvm/Function.h" 24#include "llvm/GlobalVariable.h" 25#include "llvm/Intrinsics.h" 26#include "llvm/Module.h" 27#include "llvm/Support/CFG.h" 28#include "llvm/Target/TargetData.h" 29#include <cstdarg> 30 31using namespace clang; 32using namespace CodeGen; 33using llvm::Value; 34 35//===----------------------------------------------------------------------===// 36// Scalar Expression Emitter 37//===----------------------------------------------------------------------===// 38 39struct BinOpInfo { 40 Value *LHS; 41 Value *RHS; 42 QualType Ty; // Computation Type. 43 const BinaryOperator *E; 44}; 45 46namespace { 47class ScalarExprEmitter 48 : public StmtVisitor<ScalarExprEmitter, Value*> { 49 CodeGenFunction &CGF; 50 CGBuilderTy &Builder; 51 bool IgnoreResultAssign; 52 llvm::LLVMContext &VMContext; 53public: 54 55 ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false) 56 : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira), 57 VMContext(cgf.getLLVMContext()) { 58 } 59 60 //===--------------------------------------------------------------------===// 61 // Utilities 62 //===--------------------------------------------------------------------===// 63 64 bool TestAndClearIgnoreResultAssign() { 65 bool I = IgnoreResultAssign; 66 IgnoreResultAssign = false; 67 return I; 68 } 69 70 const llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); } 71 LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); } 72 LValue EmitCheckedLValue(const Expr *E) { return CGF.EmitCheckedLValue(E); } 73 74 Value *EmitLoadOfLValue(LValue LV, QualType T) { 75 return CGF.EmitLoadOfLValue(LV, T).getScalarVal(); 76 } 77 78 /// EmitLoadOfLValue - Given an expression with complex type that represents a 79 /// value l-value, this method emits the address of the l-value, then loads 80 /// and returns the result. 81 Value *EmitLoadOfLValue(const Expr *E) { 82 return EmitLoadOfLValue(EmitCheckedLValue(E), E->getType()); 83 } 84 85 /// EmitConversionToBool - Convert the specified expression value to a 86 /// boolean (i1) truth value. This is equivalent to "Val != 0". 87 Value *EmitConversionToBool(Value *Src, QualType DstTy); 88 89 /// EmitScalarConversion - Emit a conversion from the specified type to the 90 /// specified destination type, both of which are LLVM scalar types. 91 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); 92 93 /// EmitComplexToScalarConversion - Emit a conversion from the specified 94 /// complex type to the specified destination type, where the destination type 95 /// is an LLVM scalar type. 96 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 97 QualType SrcTy, QualType DstTy); 98 99 //===--------------------------------------------------------------------===// 100 // Visitor Methods 101 //===--------------------------------------------------------------------===// 102 103 Value *VisitStmt(Stmt *S) { 104 S->dump(CGF.getContext().getSourceManager()); 105 assert(0 && "Stmt can't have complex result type!"); 106 return 0; 107 } 108 Value *VisitExpr(Expr *S); 109 110 Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); } 111 112 // Leaves. 113 Value *VisitIntegerLiteral(const IntegerLiteral *E) { 114 return llvm::ConstantInt::get(VMContext, E->getValue()); 115 } 116 Value *VisitFloatingLiteral(const FloatingLiteral *E) { 117 return llvm::ConstantFP::get(VMContext, E->getValue()); 118 } 119 Value *VisitCharacterLiteral(const CharacterLiteral *E) { 120 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 121 } 122 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 123 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 124 } 125 Value *VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) { 126 return llvm::Constant::getNullValue(ConvertType(E->getType())); 127 } 128 Value *VisitGNUNullExpr(const GNUNullExpr *E) { 129 return llvm::Constant::getNullValue(ConvertType(E->getType())); 130 } 131 Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { 132 return llvm::ConstantInt::get(ConvertType(E->getType()), 133 CGF.getContext().typesAreCompatible( 134 E->getArgType1(), E->getArgType2())); 135 } 136 Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); 137 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 138 llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel()); 139 return Builder.CreateBitCast(V, ConvertType(E->getType())); 140 } 141 142 // l-values. 143 Value *VisitDeclRefExpr(DeclRefExpr *E) { 144 Expr::EvalResult Result; 145 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 146 assert(!Result.HasSideEffects && "Constant declref with side-effect?!"); 147 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 148 } 149 return EmitLoadOfLValue(E); 150 } 151 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 152 return CGF.EmitObjCSelectorExpr(E); 153 } 154 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 155 return CGF.EmitObjCProtocolExpr(E); 156 } 157 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 158 return EmitLoadOfLValue(E); 159 } 160 Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { 161 return EmitLoadOfLValue(E); 162 } 163 Value *VisitObjCImplicitSetterGetterRefExpr( 164 ObjCImplicitSetterGetterRefExpr *E) { 165 return EmitLoadOfLValue(E); 166 } 167 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 168 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 169 } 170 171 Value *VisitObjCIsaExpr(ObjCIsaExpr *E) { 172 LValue LV = CGF.EmitObjCIsaExpr(E); 173 Value *V = CGF.EmitLoadOfLValue(LV, E->getType()).getScalarVal(); 174 return V; 175 } 176 177 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 178 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 179 Value *VisitMemberExpr(MemberExpr *E); 180 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 181 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 182 return EmitLoadOfLValue(E); 183 } 184 185 Value *VisitInitListExpr(InitListExpr *E); 186 187 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { 188 return llvm::Constant::getNullValue(ConvertType(E->getType())); 189 } 190 Value *VisitCastExpr(CastExpr *E) { 191 // Make sure to evaluate VLA bounds now so that we have them for later. 192 if (E->getType()->isVariablyModifiedType()) 193 CGF.EmitVLASize(E->getType()); 194 195 return EmitCastExpr(E); 196 } 197 Value *EmitCastExpr(CastExpr *E); 198 199 Value *VisitCallExpr(const CallExpr *E) { 200 if (E->getCallReturnType()->isReferenceType()) 201 return EmitLoadOfLValue(E); 202 203 return CGF.EmitCallExpr(E).getScalarVal(); 204 } 205 206 Value *VisitStmtExpr(const StmtExpr *E); 207 208 Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E); 209 210 // Unary Operators. 211 Value *VisitPrePostIncDec(const UnaryOperator *E, bool isInc, bool isPre) { 212 LValue LV = EmitLValue(E->getSubExpr()); 213 return CGF.EmitScalarPrePostIncDec(E, LV, isInc, isPre); 214 } 215 Value *VisitUnaryPostDec(const UnaryOperator *E) { 216 return VisitPrePostIncDec(E, false, false); 217 } 218 Value *VisitUnaryPostInc(const UnaryOperator *E) { 219 return VisitPrePostIncDec(E, true, false); 220 } 221 Value *VisitUnaryPreDec(const UnaryOperator *E) { 222 return VisitPrePostIncDec(E, false, true); 223 } 224 Value *VisitUnaryPreInc(const UnaryOperator *E) { 225 return VisitPrePostIncDec(E, true, true); 226 } 227 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 228 return EmitLValue(E->getSubExpr()).getAddress(); 229 } 230 Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } 231 Value *VisitUnaryPlus(const UnaryOperator *E) { 232 // This differs from gcc, though, most likely due to a bug in gcc. 233 TestAndClearIgnoreResultAssign(); 234 return Visit(E->getSubExpr()); 235 } 236 Value *VisitUnaryMinus (const UnaryOperator *E); 237 Value *VisitUnaryNot (const UnaryOperator *E); 238 Value *VisitUnaryLNot (const UnaryOperator *E); 239 Value *VisitUnaryReal (const UnaryOperator *E); 240 Value *VisitUnaryImag (const UnaryOperator *E); 241 Value *VisitUnaryExtension(const UnaryOperator *E) { 242 return Visit(E->getSubExpr()); 243 } 244 Value *VisitUnaryOffsetOf(const UnaryOperator *E); 245 246 // C++ 247 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 248 return Visit(DAE->getExpr()); 249 } 250 Value *VisitCXXThisExpr(CXXThisExpr *TE) { 251 return CGF.LoadCXXThis(); 252 } 253 254 Value *VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) { 255 return CGF.EmitCXXExprWithTemporaries(E).getScalarVal(); 256 } 257 Value *VisitCXXNewExpr(const CXXNewExpr *E) { 258 return CGF.EmitCXXNewExpr(E); 259 } 260 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { 261 CGF.EmitCXXDeleteExpr(E); 262 return 0; 263 } 264 Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) { 265 return llvm::ConstantInt::get(Builder.getInt1Ty(), 266 E->EvaluateTrait(CGF.getContext())); 267 } 268 269 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { 270 // C++ [expr.pseudo]p1: 271 // The result shall only be used as the operand for the function call 272 // operator (), and the result of such a call has type void. The only 273 // effect is the evaluation of the postfix-expression before the dot or 274 // arrow. 275 CGF.EmitScalarExpr(E->getBase()); 276 return 0; 277 } 278 279 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { 280 return llvm::Constant::getNullValue(ConvertType(E->getType())); 281 } 282 283 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { 284 CGF.EmitCXXThrowExpr(E); 285 return 0; 286 } 287 288 // Binary Operators. 289 Value *EmitMul(const BinOpInfo &Ops) { 290 if (CGF.getContext().getLangOptions().OverflowChecking 291 && Ops.Ty->isSignedIntegerType()) 292 return EmitOverflowCheckedBinOp(Ops); 293 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 294 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 295 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 296 } 297 /// Create a binary op that checks for overflow. 298 /// Currently only supports +, - and *. 299 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 300 Value *EmitDiv(const BinOpInfo &Ops); 301 Value *EmitRem(const BinOpInfo &Ops); 302 Value *EmitAdd(const BinOpInfo &Ops); 303 Value *EmitSub(const BinOpInfo &Ops); 304 Value *EmitShl(const BinOpInfo &Ops); 305 Value *EmitShr(const BinOpInfo &Ops); 306 Value *EmitAnd(const BinOpInfo &Ops) { 307 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 308 } 309 Value *EmitXor(const BinOpInfo &Ops) { 310 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 311 } 312 Value *EmitOr (const BinOpInfo &Ops) { 313 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 314 } 315 316 BinOpInfo EmitBinOps(const BinaryOperator *E); 317 LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E, 318 Value *(ScalarExprEmitter::*F)(const BinOpInfo &), 319 Value *&BitFieldResult); 320 321 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 322 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 323 324 // Binary operators and binary compound assignment operators. 325#define HANDLEBINOP(OP) \ 326 Value *VisitBin ## OP(const BinaryOperator *E) { \ 327 return Emit ## OP(EmitBinOps(E)); \ 328 } \ 329 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 330 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 331 } 332 HANDLEBINOP(Mul) 333 HANDLEBINOP(Div) 334 HANDLEBINOP(Rem) 335 HANDLEBINOP(Add) 336 HANDLEBINOP(Sub) 337 HANDLEBINOP(Shl) 338 HANDLEBINOP(Shr) 339 HANDLEBINOP(And) 340 HANDLEBINOP(Xor) 341 HANDLEBINOP(Or) 342#undef HANDLEBINOP 343 344 // Comparisons. 345 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 346 unsigned SICmpOpc, unsigned FCmpOpc); 347#define VISITCOMP(CODE, UI, SI, FP) \ 348 Value *VisitBin##CODE(const BinaryOperator *E) { \ 349 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 350 llvm::FCmpInst::FP); } 351 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT) 352 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT) 353 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE) 354 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE) 355 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ) 356 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE) 357#undef VISITCOMP 358 359 Value *VisitBinAssign (const BinaryOperator *E); 360 361 Value *VisitBinLAnd (const BinaryOperator *E); 362 Value *VisitBinLOr (const BinaryOperator *E); 363 Value *VisitBinComma (const BinaryOperator *E); 364 365 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } 366 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); } 367 368 // Other Operators. 369 Value *VisitBlockExpr(const BlockExpr *BE); 370 Value *VisitConditionalOperator(const ConditionalOperator *CO); 371 Value *VisitChooseExpr(ChooseExpr *CE); 372 Value *VisitVAArgExpr(VAArgExpr *VE); 373 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 374 return CGF.EmitObjCStringLiteral(E); 375 } 376}; 377} // end anonymous namespace. 378 379//===----------------------------------------------------------------------===// 380// Utilities 381//===----------------------------------------------------------------------===// 382 383/// EmitConversionToBool - Convert the specified expression value to a 384/// boolean (i1) truth value. This is equivalent to "Val != 0". 385Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 386 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs"); 387 388 if (SrcType->isRealFloatingType()) { 389 // Compare against 0.0 for fp scalars. 390 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 391 return Builder.CreateFCmpUNE(Src, Zero, "tobool"); 392 } 393 394 if (SrcType->isMemberPointerType()) { 395 // Compare against -1. 396 llvm::Value *NegativeOne = llvm::Constant::getAllOnesValue(Src->getType()); 397 return Builder.CreateICmpNE(Src, NegativeOne, "tobool"); 398 } 399 400 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 401 "Unknown scalar type to convert"); 402 403 // Because of the type rules of C, we often end up computing a logical value, 404 // then zero extending it to int, then wanting it as a logical value again. 405 // Optimize this common case. 406 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) { 407 if (ZI->getOperand(0)->getType() == 408 llvm::Type::getInt1Ty(CGF.getLLVMContext())) { 409 Value *Result = ZI->getOperand(0); 410 // If there aren't any more uses, zap the instruction to save space. 411 // Note that there can be more uses, for example if this 412 // is the result of an assignment. 413 if (ZI->use_empty()) 414 ZI->eraseFromParent(); 415 return Result; 416 } 417 } 418 419 // Compare against an integer or pointer null. 420 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 421 return Builder.CreateICmpNE(Src, Zero, "tobool"); 422} 423 424/// EmitScalarConversion - Emit a conversion from the specified type to the 425/// specified destination type, both of which are LLVM scalar types. 426Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 427 QualType DstType) { 428 SrcType = CGF.getContext().getCanonicalType(SrcType); 429 DstType = CGF.getContext().getCanonicalType(DstType); 430 if (SrcType == DstType) return Src; 431 432 if (DstType->isVoidType()) return 0; 433 434 llvm::LLVMContext &VMContext = CGF.getLLVMContext(); 435 436 // Handle conversions to bool first, they are special: comparisons against 0. 437 if (DstType->isBooleanType()) 438 return EmitConversionToBool(Src, SrcType); 439 440 const llvm::Type *DstTy = ConvertType(DstType); 441 442 // Ignore conversions like int -> uint. 443 if (Src->getType() == DstTy) 444 return Src; 445 446 // Handle pointer conversions next: pointers can only be converted to/from 447 // other pointers and integers. Check for pointer types in terms of LLVM, as 448 // some native types (like Obj-C id) may map to a pointer type. 449 if (isa<llvm::PointerType>(DstTy)) { 450 // The source value may be an integer, or a pointer. 451 if (isa<llvm::PointerType>(Src->getType())) 452 return Builder.CreateBitCast(Src, DstTy, "conv"); 453 454 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 455 // First, convert to the correct width so that we control the kind of 456 // extension. 457 const llvm::Type *MiddleTy = 458 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 459 bool InputSigned = SrcType->isSignedIntegerType(); 460 llvm::Value* IntResult = 461 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 462 // Then, cast to pointer. 463 return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); 464 } 465 466 if (isa<llvm::PointerType>(Src->getType())) { 467 // Must be an ptr to int cast. 468 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 469 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 470 } 471 472 // A scalar can be splatted to an extended vector of the same element type 473 if (DstType->isExtVectorType() && !SrcType->isVectorType()) { 474 // Cast the scalar to element type 475 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType(); 476 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 477 478 // Insert the element in element zero of an undef vector 479 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 480 llvm::Value *Idx = 481 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0); 482 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 483 484 // Splat the element across to all elements 485 llvm::SmallVector<llvm::Constant*, 16> Args; 486 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 487 for (unsigned i = 0; i < NumElements; i++) 488 Args.push_back(llvm::ConstantInt::get( 489 llvm::Type::getInt32Ty(VMContext), 0)); 490 491 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 492 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 493 return Yay; 494 } 495 496 // Allow bitcast from vector to integer/fp of the same size. 497 if (isa<llvm::VectorType>(Src->getType()) || 498 isa<llvm::VectorType>(DstTy)) 499 return Builder.CreateBitCast(Src, DstTy, "conv"); 500 501 // Finally, we have the arithmetic types: real int/float. 502 if (isa<llvm::IntegerType>(Src->getType())) { 503 bool InputSigned = SrcType->isSignedIntegerType(); 504 if (isa<llvm::IntegerType>(DstTy)) 505 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 506 else if (InputSigned) 507 return Builder.CreateSIToFP(Src, DstTy, "conv"); 508 else 509 return Builder.CreateUIToFP(Src, DstTy, "conv"); 510 } 511 512 assert(Src->getType()->isFloatingPointTy() && "Unknown real conversion"); 513 if (isa<llvm::IntegerType>(DstTy)) { 514 if (DstType->isSignedIntegerType()) 515 return Builder.CreateFPToSI(Src, DstTy, "conv"); 516 else 517 return Builder.CreateFPToUI(Src, DstTy, "conv"); 518 } 519 520 assert(DstTy->isFloatingPointTy() && "Unknown real conversion"); 521 if (DstTy->getTypeID() < Src->getType()->getTypeID()) 522 return Builder.CreateFPTrunc(Src, DstTy, "conv"); 523 else 524 return Builder.CreateFPExt(Src, DstTy, "conv"); 525} 526 527/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 528/// type to the specified destination type, where the destination type is an 529/// LLVM scalar type. 530Value *ScalarExprEmitter:: 531EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 532 QualType SrcTy, QualType DstTy) { 533 // Get the source element type. 534 SrcTy = SrcTy->getAs<ComplexType>()->getElementType(); 535 536 // Handle conversions to bool first, they are special: comparisons against 0. 537 if (DstTy->isBooleanType()) { 538 // Complex != 0 -> (Real != 0) | (Imag != 0) 539 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 540 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 541 return Builder.CreateOr(Src.first, Src.second, "tobool"); 542 } 543 544 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 545 // the imaginary part of the complex value is discarded and the value of the 546 // real part is converted according to the conversion rules for the 547 // corresponding real type. 548 return EmitScalarConversion(Src.first, SrcTy, DstTy); 549} 550 551 552//===----------------------------------------------------------------------===// 553// Visitor Methods 554//===----------------------------------------------------------------------===// 555 556Value *ScalarExprEmitter::VisitExpr(Expr *E) { 557 CGF.ErrorUnsupported(E, "scalar expression"); 558 if (E->getType()->isVoidType()) 559 return 0; 560 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 561} 562 563Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 564 llvm::SmallVector<llvm::Constant*, 32> indices; 565 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 566 indices.push_back(cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i)))); 567 } 568 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 569 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 570 Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); 571 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 572} 573Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { 574 Expr::EvalResult Result; 575 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 576 if (E->isArrow()) 577 CGF.EmitScalarExpr(E->getBase()); 578 else 579 EmitLValue(E->getBase()); 580 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 581 } 582 return EmitLoadOfLValue(E); 583} 584 585Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 586 TestAndClearIgnoreResultAssign(); 587 588 // Emit subscript expressions in rvalue context's. For most cases, this just 589 // loads the lvalue formed by the subscript expr. However, we have to be 590 // careful, because the base of a vector subscript is occasionally an rvalue, 591 // so we can't get it as an lvalue. 592 if (!E->getBase()->getType()->isVectorType()) 593 return EmitLoadOfLValue(E); 594 595 // Handle the vector case. The base must be a vector, the index must be an 596 // integer value. 597 Value *Base = Visit(E->getBase()); 598 Value *Idx = Visit(E->getIdx()); 599 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerType(); 600 Idx = Builder.CreateIntCast(Idx, 601 llvm::Type::getInt32Ty(CGF.getLLVMContext()), 602 IdxSigned, 603 "vecidxcast"); 604 return Builder.CreateExtractElement(Base, Idx, "vecext"); 605} 606 607static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, 608 unsigned Off, const llvm::Type *I32Ty) { 609 int MV = SVI->getMaskValue(Idx); 610 if (MV == -1) 611 return llvm::UndefValue::get(I32Ty); 612 return llvm::ConstantInt::get(I32Ty, Off+MV); 613} 614 615Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) { 616 bool Ignore = TestAndClearIgnoreResultAssign(); 617 (void)Ignore; 618 assert (Ignore == false && "init list ignored"); 619 unsigned NumInitElements = E->getNumInits(); 620 621 if (E->hadArrayRangeDesignator()) 622 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 623 624 const llvm::VectorType *VType = 625 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 626 627 // We have a scalar in braces. Just use the first element. 628 if (!VType) 629 return Visit(E->getInit(0)); 630 631 unsigned ResElts = VType->getNumElements(); 632 const llvm::Type *I32Ty = llvm::Type::getInt32Ty(CGF.getLLVMContext()); 633 634 // Loop over initializers collecting the Value for each, and remembering 635 // whether the source was swizzle (ExtVectorElementExpr). This will allow 636 // us to fold the shuffle for the swizzle into the shuffle for the vector 637 // initializer, since LLVM optimizers generally do not want to touch 638 // shuffles. 639 unsigned CurIdx = 0; 640 bool VIsUndefShuffle = false; 641 llvm::Value *V = llvm::UndefValue::get(VType); 642 for (unsigned i = 0; i != NumInitElements; ++i) { 643 Expr *IE = E->getInit(i); 644 Value *Init = Visit(IE); 645 llvm::SmallVector<llvm::Constant*, 16> Args; 646 647 const llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType()); 648 649 // Handle scalar elements. If the scalar initializer is actually one 650 // element of a different vector of the same width, use shuffle instead of 651 // extract+insert. 652 if (!VVT) { 653 if (isa<ExtVectorElementExpr>(IE)) { 654 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init); 655 656 if (EI->getVectorOperandType()->getNumElements() == ResElts) { 657 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand()); 658 Value *LHS = 0, *RHS = 0; 659 if (CurIdx == 0) { 660 // insert into undef -> shuffle (src, undef) 661 Args.push_back(C); 662 for (unsigned j = 1; j != ResElts; ++j) 663 Args.push_back(llvm::UndefValue::get(I32Ty)); 664 665 LHS = EI->getVectorOperand(); 666 RHS = V; 667 VIsUndefShuffle = true; 668 } else if (VIsUndefShuffle) { 669 // insert into undefshuffle && size match -> shuffle (v, src) 670 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V); 671 for (unsigned j = 0; j != CurIdx; ++j) 672 Args.push_back(getMaskElt(SVV, j, 0, I32Ty)); 673 Args.push_back(llvm::ConstantInt::get(I32Ty, 674 ResElts + C->getZExtValue())); 675 for (unsigned j = CurIdx + 1; j != ResElts; ++j) 676 Args.push_back(llvm::UndefValue::get(I32Ty)); 677 678 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 679 RHS = EI->getVectorOperand(); 680 VIsUndefShuffle = false; 681 } 682 if (!Args.empty()) { 683 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 684 V = Builder.CreateShuffleVector(LHS, RHS, Mask); 685 ++CurIdx; 686 continue; 687 } 688 } 689 } 690 Value *Idx = llvm::ConstantInt::get(I32Ty, CurIdx); 691 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 692 VIsUndefShuffle = false; 693 ++CurIdx; 694 continue; 695 } 696 697 unsigned InitElts = VVT->getNumElements(); 698 699 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's 700 // input is the same width as the vector being constructed, generate an 701 // optimized shuffle of the swizzle input into the result. 702 unsigned Offset = (CurIdx == 0) ? 0 : ResElts; 703 if (isa<ExtVectorElementExpr>(IE)) { 704 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init); 705 Value *SVOp = SVI->getOperand(0); 706 const llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType()); 707 708 if (OpTy->getNumElements() == ResElts) { 709 for (unsigned j = 0; j != CurIdx; ++j) { 710 // If the current vector initializer is a shuffle with undef, merge 711 // this shuffle directly into it. 712 if (VIsUndefShuffle) { 713 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0, 714 I32Ty)); 715 } else { 716 Args.push_back(llvm::ConstantInt::get(I32Ty, j)); 717 } 718 } 719 for (unsigned j = 0, je = InitElts; j != je; ++j) 720 Args.push_back(getMaskElt(SVI, j, Offset, I32Ty)); 721 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 722 Args.push_back(llvm::UndefValue::get(I32Ty)); 723 724 if (VIsUndefShuffle) 725 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 726 727 Init = SVOp; 728 } 729 } 730 731 // Extend init to result vector length, and then shuffle its contribution 732 // to the vector initializer into V. 733 if (Args.empty()) { 734 for (unsigned j = 0; j != InitElts; ++j) 735 Args.push_back(llvm::ConstantInt::get(I32Ty, j)); 736 for (unsigned j = InitElts; j != ResElts; ++j) 737 Args.push_back(llvm::UndefValue::get(I32Ty)); 738 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 739 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), 740 Mask, "vext"); 741 742 Args.clear(); 743 for (unsigned j = 0; j != CurIdx; ++j) 744 Args.push_back(llvm::ConstantInt::get(I32Ty, j)); 745 for (unsigned j = 0; j != InitElts; ++j) 746 Args.push_back(llvm::ConstantInt::get(I32Ty, j+Offset)); 747 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 748 Args.push_back(llvm::UndefValue::get(I32Ty)); 749 } 750 751 // If V is undef, make sure it ends up on the RHS of the shuffle to aid 752 // merging subsequent shuffles into this one. 753 if (CurIdx == 0) 754 std::swap(V, Init); 755 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 756 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); 757 VIsUndefShuffle = isa<llvm::UndefValue>(Init); 758 CurIdx += InitElts; 759 } 760 761 // FIXME: evaluate codegen vs. shuffling against constant null vector. 762 // Emit remaining default initializers. 763 const llvm::Type *EltTy = VType->getElementType(); 764 765 // Emit remaining default initializers 766 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { 767 Value *Idx = llvm::ConstantInt::get(I32Ty, CurIdx); 768 llvm::Value *Init = llvm::Constant::getNullValue(EltTy); 769 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 770 } 771 return V; 772} 773 774static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { 775 const Expr *E = CE->getSubExpr(); 776 777 if (CE->getCastKind() == CastExpr::CK_UncheckedDerivedToBase) 778 return false; 779 780 if (isa<CXXThisExpr>(E)) { 781 // We always assume that 'this' is never null. 782 return false; 783 } 784 785 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { 786 // And that lvalue casts are never null. 787 if (ICE->isLvalueCast()) 788 return false; 789 } 790 791 return true; 792} 793 794// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 795// have to handle a more broad range of conversions than explicit casts, as they 796// handle things like function to ptr-to-function decay etc. 797Value *ScalarExprEmitter::EmitCastExpr(CastExpr *CE) { 798 Expr *E = CE->getSubExpr(); 799 QualType DestTy = CE->getType(); 800 CastExpr::CastKind Kind = CE->getCastKind(); 801 802 if (!DestTy->isVoidType()) 803 TestAndClearIgnoreResultAssign(); 804 805 // Since almost all cast kinds apply to scalars, this switch doesn't have 806 // a default case, so the compiler will warn on a missing case. The cases 807 // are in the same order as in the CastKind enum. 808 switch (Kind) { 809 case CastExpr::CK_Unknown: 810 // FIXME: All casts should have a known kind! 811 //assert(0 && "Unknown cast kind!"); 812 break; 813 814 case CastExpr::CK_AnyPointerToObjCPointerCast: 815 case CastExpr::CK_AnyPointerToBlockPointerCast: 816 case CastExpr::CK_BitCast: { 817 Value *Src = Visit(const_cast<Expr*>(E)); 818 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 819 } 820 case CastExpr::CK_NoOp: 821 case CastExpr::CK_UserDefinedConversion: 822 return Visit(const_cast<Expr*>(E)); 823 824 case CastExpr::CK_BaseToDerived: { 825 const CXXRecordDecl *BaseClassDecl = 826 E->getType()->getCXXRecordDeclForPointerType(); 827 const CXXRecordDecl *DerivedClassDecl = 828 DestTy->getCXXRecordDeclForPointerType(); 829 830 Value *Src = Visit(const_cast<Expr*>(E)); 831 832 bool NullCheckValue = ShouldNullCheckClassCastValue(CE); 833 return CGF.GetAddressOfDerivedClass(Src, BaseClassDecl, DerivedClassDecl, 834 NullCheckValue); 835 } 836 case CastExpr::CK_UncheckedDerivedToBase: 837 case CastExpr::CK_DerivedToBase: { 838 const RecordType *DerivedClassTy = 839 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 840 CXXRecordDecl *DerivedClassDecl = 841 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 842 843 return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl, 844 CE->getBasePath(), 845 ShouldNullCheckClassCastValue(CE)); 846 } 847 case CastExpr::CK_Dynamic: { 848 Value *V = Visit(const_cast<Expr*>(E)); 849 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 850 return CGF.EmitDynamicCast(V, DCE); 851 } 852 case CastExpr::CK_ToUnion: 853 assert(0 && "Should be unreachable!"); 854 break; 855 856 case CastExpr::CK_ArrayToPointerDecay: { 857 assert(E->getType()->isArrayType() && 858 "Array to pointer decay must have array source type!"); 859 860 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 861 862 // Note that VLA pointers are always decayed, so we don't need to do 863 // anything here. 864 if (!E->getType()->isVariableArrayType()) { 865 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 866 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 867 ->getElementType()) && 868 "Expected pointer to array"); 869 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 870 } 871 872 return V; 873 } 874 case CastExpr::CK_FunctionToPointerDecay: 875 return EmitLValue(E).getAddress(); 876 877 case CastExpr::CK_NullToMemberPointer: 878 return CGF.CGM.EmitNullConstant(DestTy); 879 880 case CastExpr::CK_BaseToDerivedMemberPointer: 881 case CastExpr::CK_DerivedToBaseMemberPointer: { 882 Value *Src = Visit(E); 883 884 // See if we need to adjust the pointer. 885 const CXXRecordDecl *BaseDecl = 886 cast<CXXRecordDecl>(E->getType()->getAs<MemberPointerType>()-> 887 getClass()->getAs<RecordType>()->getDecl()); 888 const CXXRecordDecl *DerivedDecl = 889 cast<CXXRecordDecl>(CE->getType()->getAs<MemberPointerType>()-> 890 getClass()->getAs<RecordType>()->getDecl()); 891 if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) 892 std::swap(DerivedDecl, BaseDecl); 893 894 if (llvm::Constant *Adj = 895 CGF.CGM.GetNonVirtualBaseClassOffset(DerivedDecl, BaseDecl)) { 896 if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) 897 Src = Builder.CreateSub(Src, Adj, "adj"); 898 else 899 Src = Builder.CreateAdd(Src, Adj, "adj"); 900 } 901 return Src; 902 } 903 904 case CastExpr::CK_ConstructorConversion: 905 assert(0 && "Should be unreachable!"); 906 break; 907 908 case CastExpr::CK_IntegralToPointer: { 909 Value *Src = Visit(const_cast<Expr*>(E)); 910 911 // First, convert to the correct width so that we control the kind of 912 // extension. 913 const llvm::Type *MiddleTy = 914 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 915 bool InputSigned = E->getType()->isSignedIntegerType(); 916 llvm::Value* IntResult = 917 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 918 919 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 920 } 921 case CastExpr::CK_PointerToIntegral: { 922 Value *Src = Visit(const_cast<Expr*>(E)); 923 return Builder.CreatePtrToInt(Src, ConvertType(DestTy)); 924 } 925 case CastExpr::CK_ToVoid: { 926 CGF.EmitAnyExpr(E, 0, false, true); 927 return 0; 928 } 929 case CastExpr::CK_VectorSplat: { 930 const llvm::Type *DstTy = ConvertType(DestTy); 931 Value *Elt = Visit(const_cast<Expr*>(E)); 932 933 // Insert the element in element zero of an undef vector 934 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 935 llvm::Value *Idx = 936 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0); 937 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 938 939 // Splat the element across to all elements 940 llvm::SmallVector<llvm::Constant*, 16> Args; 941 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 942 for (unsigned i = 0; i < NumElements; i++) 943 Args.push_back(llvm::ConstantInt::get( 944 llvm::Type::getInt32Ty(VMContext), 0)); 945 946 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 947 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 948 return Yay; 949 } 950 case CastExpr::CK_IntegralCast: 951 case CastExpr::CK_IntegralToFloating: 952 case CastExpr::CK_FloatingToIntegral: 953 case CastExpr::CK_FloatingCast: 954 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 955 956 case CastExpr::CK_MemberPointerToBoolean: 957 return CGF.EvaluateExprAsBool(E); 958 } 959 960 // Handle cases where the source is an non-complex type. 961 962 if (!CGF.hasAggregateLLVMType(E->getType())) { 963 Value *Src = Visit(const_cast<Expr*>(E)); 964 965 // Use EmitScalarConversion to perform the conversion. 966 return EmitScalarConversion(Src, E->getType(), DestTy); 967 } 968 969 if (E->getType()->isAnyComplexType()) { 970 // Handle cases where the source is a complex type. 971 bool IgnoreImag = true; 972 bool IgnoreImagAssign = true; 973 bool IgnoreReal = IgnoreResultAssign; 974 bool IgnoreRealAssign = IgnoreResultAssign; 975 if (DestTy->isBooleanType()) 976 IgnoreImagAssign = IgnoreImag = false; 977 else if (DestTy->isVoidType()) { 978 IgnoreReal = IgnoreImag = false; 979 IgnoreRealAssign = IgnoreImagAssign = true; 980 } 981 CodeGenFunction::ComplexPairTy V 982 = CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign, 983 IgnoreImagAssign); 984 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 985 } 986 987 // Okay, this is a cast from an aggregate. It must be a cast to void. Just 988 // evaluate the result and return. 989 CGF.EmitAggExpr(E, 0, false, true); 990 return 0; 991} 992 993Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 994 return CGF.EmitCompoundStmt(*E->getSubStmt(), 995 !E->getType()->isVoidType()).getScalarVal(); 996} 997 998Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 999 llvm::Value *V = CGF.GetAddrOfBlockDecl(E); 1000 if (E->getType().isObjCGCWeak()) 1001 return CGF.CGM.getObjCRuntime().EmitObjCWeakRead(CGF, V); 1002 return Builder.CreateLoad(V, "tmp"); 1003} 1004 1005//===----------------------------------------------------------------------===// 1006// Unary Operators 1007//===----------------------------------------------------------------------===// 1008 1009Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1010 TestAndClearIgnoreResultAssign(); 1011 Value *Op = Visit(E->getSubExpr()); 1012 if (Op->getType()->isFPOrFPVectorTy()) 1013 return Builder.CreateFNeg(Op, "neg"); 1014 return Builder.CreateNeg(Op, "neg"); 1015} 1016 1017Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1018 TestAndClearIgnoreResultAssign(); 1019 Value *Op = Visit(E->getSubExpr()); 1020 return Builder.CreateNot(Op, "neg"); 1021} 1022 1023Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1024 // Compare operand to zero. 1025 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1026 1027 // Invert value. 1028 // TODO: Could dynamically modify easy computations here. For example, if 1029 // the operand is an icmp ne, turn into icmp eq. 1030 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1031 1032 // ZExt result to the expr type. 1033 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1034} 1035 1036/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of 1037/// argument of the sizeof expression as an integer. 1038Value * 1039ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { 1040 QualType TypeToSize = E->getTypeOfArgument(); 1041 if (E->isSizeOf()) { 1042 if (const VariableArrayType *VAT = 1043 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1044 if (E->isArgumentType()) { 1045 // sizeof(type) - make sure to emit the VLA size. 1046 CGF.EmitVLASize(TypeToSize); 1047 } else { 1048 // C99 6.5.3.4p2: If the argument is an expression of type 1049 // VLA, it is evaluated. 1050 CGF.EmitAnyExpr(E->getArgumentExpr()); 1051 } 1052 1053 return CGF.GetVLASize(VAT); 1054 } 1055 } 1056 1057 // If this isn't sizeof(vla), the result must be constant; use the constant 1058 // folding logic so we don't have to duplicate it here. 1059 Expr::EvalResult Result; 1060 E->Evaluate(Result, CGF.getContext()); 1061 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 1062} 1063 1064Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1065 Expr *Op = E->getSubExpr(); 1066 if (Op->getType()->isAnyComplexType()) 1067 return CGF.EmitComplexExpr(Op, false, true, false, true).first; 1068 return Visit(Op); 1069} 1070Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1071 Expr *Op = E->getSubExpr(); 1072 if (Op->getType()->isAnyComplexType()) 1073 return CGF.EmitComplexExpr(Op, true, false, true, false).second; 1074 1075 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1076 // effects are evaluated, but not the actual value. 1077 if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) 1078 CGF.EmitLValue(Op); 1079 else 1080 CGF.EmitScalarExpr(Op, true); 1081 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1082} 1083 1084Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) { 1085 Value* ResultAsPtr = EmitLValue(E->getSubExpr()).getAddress(); 1086 const llvm::Type* ResultType = ConvertType(E->getType()); 1087 return Builder.CreatePtrToInt(ResultAsPtr, ResultType, "offsetof"); 1088} 1089 1090//===----------------------------------------------------------------------===// 1091// Binary Operators 1092//===----------------------------------------------------------------------===// 1093 1094BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1095 TestAndClearIgnoreResultAssign(); 1096 BinOpInfo Result; 1097 Result.LHS = Visit(E->getLHS()); 1098 Result.RHS = Visit(E->getRHS()); 1099 Result.Ty = E->getType(); 1100 Result.E = E; 1101 return Result; 1102} 1103 1104LValue ScalarExprEmitter::EmitCompoundAssignLValue( 1105 const CompoundAssignOperator *E, 1106 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &), 1107 Value *&BitFieldResult) { 1108 QualType LHSTy = E->getLHS()->getType(); 1109 BitFieldResult = 0; 1110 BinOpInfo OpInfo; 1111 1112 if (E->getComputationResultType()->isAnyComplexType()) { 1113 // This needs to go through the complex expression emitter, but it's a tad 1114 // complicated to do that... I'm leaving it out for now. (Note that we do 1115 // actually need the imaginary part of the RHS for multiplication and 1116 // division.) 1117 CGF.ErrorUnsupported(E, "complex compound assignment"); 1118 llvm::UndefValue::get(CGF.ConvertType(E->getType())); 1119 return LValue(); 1120 } 1121 1122 // Emit the RHS first. __block variables need to have the rhs evaluated 1123 // first, plus this should improve codegen a little. 1124 OpInfo.RHS = Visit(E->getRHS()); 1125 OpInfo.Ty = E->getComputationResultType(); 1126 OpInfo.E = E; 1127 // Load/convert the LHS. 1128 LValue LHSLV = EmitCheckedLValue(E->getLHS()); 1129 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 1130 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 1131 E->getComputationLHSType()); 1132 1133 // Expand the binary operator. 1134 Value *Result = (this->*Func)(OpInfo); 1135 1136 // Convert the result back to the LHS type. 1137 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 1138 1139 // Store the result value into the LHS lvalue. Bit-fields are handled 1140 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 1141 // 'An assignment expression has the value of the left operand after the 1142 // assignment...'. 1143 if (LHSLV.isBitField()) { 1144 if (!LHSLV.isVolatileQualified()) { 1145 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, 1146 &Result); 1147 BitFieldResult = Result; 1148 return LHSLV; 1149 } else 1150 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy); 1151 } else 1152 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); 1153 return LHSLV; 1154} 1155 1156Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 1157 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 1158 bool Ignore = TestAndClearIgnoreResultAssign(); 1159 Value *BitFieldResult; 1160 LValue LHSLV = EmitCompoundAssignLValue(E, Func, BitFieldResult); 1161 if (BitFieldResult) 1162 return BitFieldResult; 1163 1164 if (Ignore) 1165 return 0; 1166 return EmitLoadOfLValue(LHSLV, E->getType()); 1167} 1168 1169 1170Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 1171 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1172 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 1173 else if (Ops.Ty->isUnsignedIntegerType()) 1174 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 1175 else 1176 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 1177} 1178 1179Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 1180 // Rem in C can't be a floating point type: C99 6.5.5p2. 1181 if (Ops.Ty->isUnsignedIntegerType()) 1182 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 1183 else 1184 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 1185} 1186 1187Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 1188 unsigned IID; 1189 unsigned OpID = 0; 1190 1191 switch (Ops.E->getOpcode()) { 1192 case BinaryOperator::Add: 1193 case BinaryOperator::AddAssign: 1194 OpID = 1; 1195 IID = llvm::Intrinsic::sadd_with_overflow; 1196 break; 1197 case BinaryOperator::Sub: 1198 case BinaryOperator::SubAssign: 1199 OpID = 2; 1200 IID = llvm::Intrinsic::ssub_with_overflow; 1201 break; 1202 case BinaryOperator::Mul: 1203 case BinaryOperator::MulAssign: 1204 OpID = 3; 1205 IID = llvm::Intrinsic::smul_with_overflow; 1206 break; 1207 default: 1208 assert(false && "Unsupported operation for overflow detection"); 1209 IID = 0; 1210 } 1211 OpID <<= 1; 1212 OpID |= 1; 1213 1214 const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1215 1216 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1); 1217 1218 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1219 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1220 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1221 1222 // Branch in case of overflow. 1223 llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); 1224 llvm::BasicBlock *overflowBB = 1225 CGF.createBasicBlock("overflow", CGF.CurFn); 1226 llvm::BasicBlock *continueBB = 1227 CGF.createBasicBlock("overflow.continue", CGF.CurFn); 1228 1229 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1230 1231 // Handle overflow 1232 1233 Builder.SetInsertPoint(overflowBB); 1234 1235 // Handler is: 1236 // long long *__overflow_handler)(long long a, long long b, char op, 1237 // char width) 1238 std::vector<const llvm::Type*> handerArgTypes; 1239 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1240 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1241 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1242 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1243 llvm::FunctionType *handlerTy = llvm::FunctionType::get( 1244 llvm::Type::getInt64Ty(VMContext), handerArgTypes, false); 1245 llvm::Value *handlerFunction = 1246 CGF.CGM.getModule().getOrInsertGlobal("__overflow_handler", 1247 llvm::PointerType::getUnqual(handlerTy)); 1248 handlerFunction = Builder.CreateLoad(handlerFunction); 1249 1250 llvm::Value *handlerResult = Builder.CreateCall4(handlerFunction, 1251 Builder.CreateSExt(Ops.LHS, llvm::Type::getInt64Ty(VMContext)), 1252 Builder.CreateSExt(Ops.RHS, llvm::Type::getInt64Ty(VMContext)), 1253 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), OpID), 1254 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), 1255 cast<llvm::IntegerType>(opTy)->getBitWidth())); 1256 1257 handlerResult = Builder.CreateTrunc(handlerResult, opTy); 1258 1259 Builder.CreateBr(continueBB); 1260 1261 // Set up the continuation 1262 Builder.SetInsertPoint(continueBB); 1263 // Get the correct result 1264 llvm::PHINode *phi = Builder.CreatePHI(opTy); 1265 phi->reserveOperandSpace(2); 1266 phi->addIncoming(result, initialBB); 1267 phi->addIncoming(handlerResult, overflowBB); 1268 1269 return phi; 1270} 1271 1272Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 1273 if (!Ops.Ty->isAnyPointerType()) { 1274 if (CGF.getContext().getLangOptions().OverflowChecking && 1275 Ops.Ty->isSignedIntegerType()) 1276 return EmitOverflowCheckedBinOp(Ops); 1277 1278 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1279 return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add"); 1280 1281 // Signed integer overflow is undefined behavior. 1282 if (Ops.Ty->isSignedIntegerType()) 1283 return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add"); 1284 1285 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1286 } 1287 1288 if (Ops.Ty->isPointerType() && 1289 Ops.Ty->getAs<PointerType>()->isVariableArrayType()) { 1290 // The amount of the addition needs to account for the VLA size 1291 CGF.ErrorUnsupported(Ops.E, "VLA pointer addition"); 1292 } 1293 Value *Ptr, *Idx; 1294 Expr *IdxExp; 1295 const PointerType *PT = Ops.E->getLHS()->getType()->getAs<PointerType>(); 1296 const ObjCObjectPointerType *OPT = 1297 Ops.E->getLHS()->getType()->getAs<ObjCObjectPointerType>(); 1298 if (PT || OPT) { 1299 Ptr = Ops.LHS; 1300 Idx = Ops.RHS; 1301 IdxExp = Ops.E->getRHS(); 1302 } else { // int + pointer 1303 PT = Ops.E->getRHS()->getType()->getAs<PointerType>(); 1304 OPT = Ops.E->getRHS()->getType()->getAs<ObjCObjectPointerType>(); 1305 assert((PT || OPT) && "Invalid add expr"); 1306 Ptr = Ops.RHS; 1307 Idx = Ops.LHS; 1308 IdxExp = Ops.E->getLHS(); 1309 } 1310 1311 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1312 if (Width < CGF.LLVMPointerWidth) { 1313 // Zero or sign extend the pointer value based on whether the index is 1314 // signed or not. 1315 const llvm::Type *IdxType = 1316 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1317 if (IdxExp->getType()->isSignedIntegerType()) 1318 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1319 else 1320 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1321 } 1322 const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType(); 1323 // Handle interface types, which are not represented with a concrete type. 1324 if (const ObjCInterfaceType *OIT = dyn_cast<ObjCInterfaceType>(ElementType)) { 1325 llvm::Value *InterfaceSize = 1326 llvm::ConstantInt::get(Idx->getType(), 1327 CGF.getContext().getTypeSizeInChars(OIT).getQuantity()); 1328 Idx = Builder.CreateMul(Idx, InterfaceSize); 1329 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1330 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1331 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1332 return Builder.CreateBitCast(Res, Ptr->getType()); 1333 } 1334 1335 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 1336 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 1337 // future proof. 1338 if (ElementType->isVoidType() || ElementType->isFunctionType()) { 1339 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1340 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1341 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1342 return Builder.CreateBitCast(Res, Ptr->getType()); 1343 } 1344 1345 return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr"); 1346} 1347 1348Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 1349 if (!isa<llvm::PointerType>(Ops.LHS->getType())) { 1350 if (CGF.getContext().getLangOptions().OverflowChecking 1351 && Ops.Ty->isSignedIntegerType()) 1352 return EmitOverflowCheckedBinOp(Ops); 1353 1354 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1355 return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub"); 1356 1357 // Signed integer overflow is undefined behavior. 1358 if (Ops.Ty->isSignedIntegerType()) 1359 return Builder.CreateNSWSub(Ops.LHS, Ops.RHS, "sub"); 1360 1361 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1362 } 1363 1364 if (Ops.E->getLHS()->getType()->isPointerType() && 1365 Ops.E->getLHS()->getType()->getAs<PointerType>()->isVariableArrayType()) { 1366 // The amount of the addition needs to account for the VLA size for 1367 // ptr-int 1368 // The amount of the division needs to account for the VLA size for 1369 // ptr-ptr. 1370 CGF.ErrorUnsupported(Ops.E, "VLA pointer subtraction"); 1371 } 1372 1373 const QualType LHSType = Ops.E->getLHS()->getType(); 1374 const QualType LHSElementType = LHSType->getPointeeType(); 1375 if (!isa<llvm::PointerType>(Ops.RHS->getType())) { 1376 // pointer - int 1377 Value *Idx = Ops.RHS; 1378 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1379 if (Width < CGF.LLVMPointerWidth) { 1380 // Zero or sign extend the pointer value based on whether the index is 1381 // signed or not. 1382 const llvm::Type *IdxType = 1383 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1384 if (Ops.E->getRHS()->getType()->isSignedIntegerType()) 1385 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1386 else 1387 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1388 } 1389 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); 1390 1391 // Handle interface types, which are not represented with a concrete type. 1392 if (const ObjCInterfaceType *OIT = 1393 dyn_cast<ObjCInterfaceType>(LHSElementType)) { 1394 llvm::Value *InterfaceSize = 1395 llvm::ConstantInt::get(Idx->getType(), 1396 CGF.getContext(). 1397 getTypeSizeInChars(OIT).getQuantity()); 1398 Idx = Builder.CreateMul(Idx, InterfaceSize); 1399 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1400 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1401 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr"); 1402 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1403 } 1404 1405 // Explicitly handle GNU void* and function pointer arithmetic 1406 // extensions. The GNU void* casts amount to no-ops since our void* type is 1407 // i8*, but this is future proof. 1408 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1409 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1410 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1411 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); 1412 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1413 } 1414 1415 return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr"); 1416 } else { 1417 // pointer - pointer 1418 Value *LHS = Ops.LHS; 1419 Value *RHS = Ops.RHS; 1420 1421 CharUnits ElementSize; 1422 1423 // Handle GCC extension for pointer arithmetic on void* and function pointer 1424 // types. 1425 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1426 ElementSize = CharUnits::One(); 1427 } else { 1428 ElementSize = CGF.getContext().getTypeSizeInChars(LHSElementType); 1429 } 1430 1431 const llvm::Type *ResultType = ConvertType(Ops.Ty); 1432 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 1433 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 1434 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 1435 1436 // Optimize out the shift for element size of 1. 1437 if (ElementSize.isOne()) 1438 return BytesBetween; 1439 1440 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 1441 // pointer difference in C is only defined in the case where both operands 1442 // are pointing to elements of an array. 1443 Value *BytesPerElt = 1444 llvm::ConstantInt::get(ResultType, ElementSize.getQuantity()); 1445 return Builder.CreateExactSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 1446 } 1447} 1448 1449Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 1450 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1451 // RHS to the same size as the LHS. 1452 Value *RHS = Ops.RHS; 1453 if (Ops.LHS->getType() != RHS->getType()) 1454 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1455 1456 if (CGF.CatchUndefined 1457 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1458 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1459 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1460 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1461 llvm::ConstantInt::get(RHS->getType(), Width)), 1462 Cont, CGF.getTrapBB()); 1463 CGF.EmitBlock(Cont); 1464 } 1465 1466 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 1467} 1468 1469Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 1470 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1471 // RHS to the same size as the LHS. 1472 Value *RHS = Ops.RHS; 1473 if (Ops.LHS->getType() != RHS->getType()) 1474 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1475 1476 if (CGF.CatchUndefined 1477 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1478 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1479 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1480 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1481 llvm::ConstantInt::get(RHS->getType(), Width)), 1482 Cont, CGF.getTrapBB()); 1483 CGF.EmitBlock(Cont); 1484 } 1485 1486 if (Ops.Ty->isUnsignedIntegerType()) 1487 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 1488 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 1489} 1490 1491Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 1492 unsigned SICmpOpc, unsigned FCmpOpc) { 1493 TestAndClearIgnoreResultAssign(); 1494 Value *Result; 1495 QualType LHSTy = E->getLHS()->getType(); 1496 if (LHSTy->isMemberFunctionPointerType()) { 1497 Value *LHSPtr = CGF.EmitAnyExprToTemp(E->getLHS()).getAggregateAddr(); 1498 Value *RHSPtr = CGF.EmitAnyExprToTemp(E->getRHS()).getAggregateAddr(); 1499 llvm::Value *LHSFunc = Builder.CreateStructGEP(LHSPtr, 0); 1500 LHSFunc = Builder.CreateLoad(LHSFunc); 1501 llvm::Value *RHSFunc = Builder.CreateStructGEP(RHSPtr, 0); 1502 RHSFunc = Builder.CreateLoad(RHSFunc); 1503 Value *ResultF = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1504 LHSFunc, RHSFunc, "cmp.func"); 1505 Value *NullPtr = llvm::Constant::getNullValue(LHSFunc->getType()); 1506 Value *ResultNull = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1507 LHSFunc, NullPtr, "cmp.null"); 1508 llvm::Value *LHSAdj = Builder.CreateStructGEP(LHSPtr, 1); 1509 LHSAdj = Builder.CreateLoad(LHSAdj); 1510 llvm::Value *RHSAdj = Builder.CreateStructGEP(RHSPtr, 1); 1511 RHSAdj = Builder.CreateLoad(RHSAdj); 1512 Value *ResultA = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1513 LHSAdj, RHSAdj, "cmp.adj"); 1514 if (E->getOpcode() == BinaryOperator::EQ) { 1515 Result = Builder.CreateOr(ResultNull, ResultA, "or.na"); 1516 Result = Builder.CreateAnd(Result, ResultF, "and.f"); 1517 } else { 1518 assert(E->getOpcode() == BinaryOperator::NE && 1519 "Member pointer comparison other than == or != ?"); 1520 Result = Builder.CreateAnd(ResultNull, ResultA, "and.na"); 1521 Result = Builder.CreateOr(Result, ResultF, "or.f"); 1522 } 1523 } else if (!LHSTy->isAnyComplexType()) { 1524 Value *LHS = Visit(E->getLHS()); 1525 Value *RHS = Visit(E->getRHS()); 1526 1527 if (LHS->getType()->isFPOrFPVectorTy()) { 1528 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 1529 LHS, RHS, "cmp"); 1530 } else if (LHSTy->isSignedIntegerType()) { 1531 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 1532 LHS, RHS, "cmp"); 1533 } else { 1534 // Unsigned integers and pointers. 1535 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1536 LHS, RHS, "cmp"); 1537 } 1538 1539 // If this is a vector comparison, sign extend the result to the appropriate 1540 // vector integer type and return it (don't convert to bool). 1541 if (LHSTy->isVectorType()) 1542 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 1543 1544 } else { 1545 // Complex Comparison: can only be an equality comparison. 1546 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 1547 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 1548 1549 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 1550 1551 Value *ResultR, *ResultI; 1552 if (CETy->isRealFloatingType()) { 1553 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1554 LHS.first, RHS.first, "cmp.r"); 1555 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1556 LHS.second, RHS.second, "cmp.i"); 1557 } else { 1558 // Complex comparisons can only be equality comparisons. As such, signed 1559 // and unsigned opcodes are the same. 1560 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1561 LHS.first, RHS.first, "cmp.r"); 1562 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1563 LHS.second, RHS.second, "cmp.i"); 1564 } 1565 1566 if (E->getOpcode() == BinaryOperator::EQ) { 1567 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 1568 } else { 1569 assert(E->getOpcode() == BinaryOperator::NE && 1570 "Complex comparison other than == or != ?"); 1571 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 1572 } 1573 } 1574 1575 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 1576} 1577 1578Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 1579 bool Ignore = TestAndClearIgnoreResultAssign(); 1580 1581 // __block variables need to have the rhs evaluated first, plus this should 1582 // improve codegen just a little. 1583 Value *RHS = Visit(E->getRHS()); 1584 LValue LHS = EmitCheckedLValue(E->getLHS()); 1585 1586 // Store the value into the LHS. Bit-fields are handled specially 1587 // because the result is altered by the store, i.e., [C99 6.5.16p1] 1588 // 'An assignment expression has the value of the left operand after 1589 // the assignment...'. 1590 if (LHS.isBitField()) { 1591 if (!LHS.isVolatileQualified()) { 1592 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), 1593 &RHS); 1594 return RHS; 1595 } else 1596 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType()); 1597 } else 1598 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 1599 if (Ignore) 1600 return 0; 1601 return EmitLoadOfLValue(LHS, E->getType()); 1602} 1603 1604Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 1605 const llvm::Type *ResTy = ConvertType(E->getType()); 1606 1607 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 1608 // If we have 1 && X, just emit X without inserting the control flow. 1609 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1610 if (Cond == 1) { // If we have 1 && X, just emit X. 1611 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1612 // ZExt result to int or bool. 1613 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 1614 } 1615 1616 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 1617 if (!CGF.ContainsLabel(E->getRHS())) 1618 return llvm::Constant::getNullValue(ResTy); 1619 } 1620 1621 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 1622 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 1623 1624 // Branch on the LHS first. If it is false, go to the failure (cont) block. 1625 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 1626 1627 // Any edges into the ContBlock are now from an (indeterminate number of) 1628 // edges from this first condition. All of these values will be false. Start 1629 // setting up the PHI node in the Cont Block for this. 1630 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1631 "", ContBlock); 1632 PN->reserveOperandSpace(2); // Normal case, two inputs. 1633 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1634 PI != PE; ++PI) 1635 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 1636 1637 CGF.BeginConditionalBranch(); 1638 CGF.EmitBlock(RHSBlock); 1639 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1640 CGF.EndConditionalBranch(); 1641 1642 // Reaquire the RHS block, as there may be subblocks inserted. 1643 RHSBlock = Builder.GetInsertBlock(); 1644 1645 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1646 // into the phi node for the edge with the value of RHSCond. 1647 CGF.EmitBlock(ContBlock); 1648 PN->addIncoming(RHSCond, RHSBlock); 1649 1650 // ZExt result to int. 1651 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); 1652} 1653 1654Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 1655 const llvm::Type *ResTy = ConvertType(E->getType()); 1656 1657 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 1658 // If we have 0 || X, just emit X without inserting the control flow. 1659 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1660 if (Cond == -1) { // If we have 0 || X, just emit X. 1661 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1662 // ZExt result to int or bool. 1663 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 1664 } 1665 1666 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 1667 if (!CGF.ContainsLabel(E->getRHS())) 1668 return llvm::ConstantInt::get(ResTy, 1); 1669 } 1670 1671 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 1672 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 1673 1674 // Branch on the LHS first. If it is true, go to the success (cont) block. 1675 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 1676 1677 // Any edges into the ContBlock are now from an (indeterminate number of) 1678 // edges from this first condition. All of these values will be true. Start 1679 // setting up the PHI node in the Cont Block for this. 1680 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1681 "", ContBlock); 1682 PN->reserveOperandSpace(2); // Normal case, two inputs. 1683 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1684 PI != PE; ++PI) 1685 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 1686 1687 CGF.BeginConditionalBranch(); 1688 1689 // Emit the RHS condition as a bool value. 1690 CGF.EmitBlock(RHSBlock); 1691 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1692 1693 CGF.EndConditionalBranch(); 1694 1695 // Reaquire the RHS block, as there may be subblocks inserted. 1696 RHSBlock = Builder.GetInsertBlock(); 1697 1698 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1699 // into the phi node for the edge with the value of RHSCond. 1700 CGF.EmitBlock(ContBlock); 1701 PN->addIncoming(RHSCond, RHSBlock); 1702 1703 // ZExt result to int. 1704 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 1705} 1706 1707Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 1708 CGF.EmitStmt(E->getLHS()); 1709 CGF.EnsureInsertPoint(); 1710 return Visit(E->getRHS()); 1711} 1712 1713//===----------------------------------------------------------------------===// 1714// Other Operators 1715//===----------------------------------------------------------------------===// 1716 1717/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 1718/// expression is cheap enough and side-effect-free enough to evaluate 1719/// unconditionally instead of conditionally. This is used to convert control 1720/// flow into selects in some cases. 1721static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 1722 CodeGenFunction &CGF) { 1723 if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) 1724 return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr(), CGF); 1725 1726 // TODO: Allow anything we can constant fold to an integer or fp constant. 1727 if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || 1728 isa<FloatingLiteral>(E)) 1729 return true; 1730 1731 // Non-volatile automatic variables too, to get "cond ? X : Y" where 1732 // X and Y are local variables. 1733 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 1734 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 1735 if (VD->hasLocalStorage() && !(CGF.getContext() 1736 .getCanonicalType(VD->getType()) 1737 .isVolatileQualified())) 1738 return true; 1739 1740 return false; 1741} 1742 1743 1744Value *ScalarExprEmitter:: 1745VisitConditionalOperator(const ConditionalOperator *E) { 1746 TestAndClearIgnoreResultAssign(); 1747 // If the condition constant folds and can be elided, try to avoid emitting 1748 // the condition and the dead arm. 1749 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ 1750 Expr *Live = E->getLHS(), *Dead = E->getRHS(); 1751 if (Cond == -1) 1752 std::swap(Live, Dead); 1753 1754 // If the dead side doesn't have labels we need, and if the Live side isn't 1755 // the gnu missing ?: extension (which we could handle, but don't bother 1756 // to), just emit the Live part. 1757 if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part 1758 Live) // Live part isn't missing. 1759 return Visit(Live); 1760 } 1761 1762 1763 // If this is a really simple expression (like x ? 4 : 5), emit this as a 1764 // select instead of as control flow. We can only do this if it is cheap and 1765 // safe to evaluate the LHS and RHS unconditionally. 1766 if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS(), 1767 CGF) && 1768 isCheapEnoughToEvaluateUnconditionally(E->getRHS(), CGF)) { 1769 llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); 1770 llvm::Value *LHS = Visit(E->getLHS()); 1771 llvm::Value *RHS = Visit(E->getRHS()); 1772 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 1773 } 1774 1775 1776 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 1777 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 1778 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 1779 Value *CondVal = 0; 1780 1781 // If we don't have the GNU missing condition extension, emit a branch on bool 1782 // the normal way. 1783 if (E->getLHS()) { 1784 // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for 1785 // the branch on bool. 1786 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); 1787 } else { 1788 // Otherwise, for the ?: extension, evaluate the conditional and then 1789 // convert it to bool the hard way. We do this explicitly because we need 1790 // the unconverted value for the missing middle value of the ?:. 1791 CondVal = CGF.EmitScalarExpr(E->getCond()); 1792 1793 // In some cases, EmitScalarConversion will delete the "CondVal" expression 1794 // if there are no extra uses (an optimization). Inhibit this by making an 1795 // extra dead use, because we're going to add a use of CondVal later. We 1796 // don't use the builder for this, because we don't want it to get optimized 1797 // away. This leaves dead code, but the ?: extension isn't common. 1798 new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", 1799 Builder.GetInsertBlock()); 1800 1801 Value *CondBoolVal = 1802 CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 1803 CGF.getContext().BoolTy); 1804 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 1805 } 1806 1807 CGF.BeginConditionalBranch(); 1808 CGF.EmitBlock(LHSBlock); 1809 1810 // Handle the GNU extension for missing LHS. 1811 Value *LHS; 1812 if (E->getLHS()) 1813 LHS = Visit(E->getLHS()); 1814 else // Perform promotions, to handle cases like "short ?: int" 1815 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); 1816 1817 CGF.EndConditionalBranch(); 1818 LHSBlock = Builder.GetInsertBlock(); 1819 CGF.EmitBranch(ContBlock); 1820 1821 CGF.BeginConditionalBranch(); 1822 CGF.EmitBlock(RHSBlock); 1823 1824 Value *RHS = Visit(E->getRHS()); 1825 CGF.EndConditionalBranch(); 1826 RHSBlock = Builder.GetInsertBlock(); 1827 CGF.EmitBranch(ContBlock); 1828 1829 CGF.EmitBlock(ContBlock); 1830 1831 // If the LHS or RHS is a throw expression, it will be legitimately null. 1832 if (!LHS) 1833 return RHS; 1834 if (!RHS) 1835 return LHS; 1836 1837 // Create a PHI node for the real part. 1838 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 1839 PN->reserveOperandSpace(2); 1840 PN->addIncoming(LHS, LHSBlock); 1841 PN->addIncoming(RHS, RHSBlock); 1842 return PN; 1843} 1844 1845Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 1846 return Visit(E->getChosenSubExpr(CGF.getContext())); 1847} 1848 1849Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 1850 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 1851 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 1852 1853 // If EmitVAArg fails, we fall back to the LLVM instruction. 1854 if (!ArgPtr) 1855 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 1856 1857 // FIXME Volatility. 1858 return Builder.CreateLoad(ArgPtr); 1859} 1860 1861Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { 1862 return CGF.BuildBlockLiteralTmp(BE); 1863} 1864 1865//===----------------------------------------------------------------------===// 1866// Entry Point into this File 1867//===----------------------------------------------------------------------===// 1868 1869/// EmitScalarExpr - Emit the computation of the specified expression of scalar 1870/// type, ignoring the result. 1871Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 1872 assert(E && !hasAggregateLLVMType(E->getType()) && 1873 "Invalid scalar expression to emit"); 1874 1875 return ScalarExprEmitter(*this, IgnoreResultAssign) 1876 .Visit(const_cast<Expr*>(E)); 1877} 1878 1879/// EmitScalarConversion - Emit a conversion from the specified type to the 1880/// specified destination type, both of which are LLVM scalar types. 1881Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 1882 QualType DstTy) { 1883 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 1884 "Invalid scalar expression to emit"); 1885 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 1886} 1887 1888/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 1889/// type to the specified destination type, where the destination type is an 1890/// LLVM scalar type. 1891Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 1892 QualType SrcTy, 1893 QualType DstTy) { 1894 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 1895 "Invalid complex -> scalar conversion"); 1896 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 1897 DstTy); 1898} 1899 1900LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) { 1901 llvm::Value *V; 1902 // object->isa or (*object).isa 1903 // Generate code as for: *(Class*)object 1904 // build Class* type 1905 const llvm::Type *ClassPtrTy = ConvertType(E->getType()); 1906 1907 Expr *BaseExpr = E->getBase(); 1908 if (BaseExpr->isLvalue(getContext()) != Expr::LV_Valid) { 1909 V = CreateTempAlloca(ClassPtrTy, "resval"); 1910 llvm::Value *Src = EmitScalarExpr(BaseExpr); 1911 Builder.CreateStore(Src, V); 1912 LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType())); 1913 V = ScalarExprEmitter(*this).EmitLoadOfLValue(LV, E->getType()); 1914 } 1915 else { 1916 if (E->isArrow()) 1917 V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr); 1918 else 1919 V = EmitLValue(BaseExpr).getAddress(); 1920 } 1921 1922 // build Class* type 1923 ClassPtrTy = ClassPtrTy->getPointerTo(); 1924 V = Builder.CreateBitCast(V, ClassPtrTy); 1925 LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType())); 1926 return LV; 1927} 1928 1929 1930LValue CodeGenFunction::EmitCompoundAssignOperatorLValue( 1931 const CompoundAssignOperator *E) { 1932 ScalarExprEmitter Scalar(*this); 1933 Value *BitFieldResult = 0; 1934 switch (E->getOpcode()) { 1935#define COMPOUND_OP(Op) \ 1936 case BinaryOperator::Op##Assign: \ 1937 return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \ 1938 BitFieldResult) 1939 COMPOUND_OP(Mul); 1940 COMPOUND_OP(Div); 1941 COMPOUND_OP(Rem); 1942 COMPOUND_OP(Add); 1943 COMPOUND_OP(Sub); 1944 COMPOUND_OP(Shl); 1945 COMPOUND_OP(Shr); 1946 COMPOUND_OP(And); 1947 COMPOUND_OP(Xor); 1948 COMPOUND_OP(Or); 1949#undef COMPOUND_OP 1950 1951 case BinaryOperator::PtrMemD: 1952 case BinaryOperator::PtrMemI: 1953 case BinaryOperator::Mul: 1954 case BinaryOperator::Div: 1955 case BinaryOperator::Rem: 1956 case BinaryOperator::Add: 1957 case BinaryOperator::Sub: 1958 case BinaryOperator::Shl: 1959 case BinaryOperator::Shr: 1960 case BinaryOperator::LT: 1961 case BinaryOperator::GT: 1962 case BinaryOperator::LE: 1963 case BinaryOperator::GE: 1964 case BinaryOperator::EQ: 1965 case BinaryOperator::NE: 1966 case BinaryOperator::And: 1967 case BinaryOperator::Xor: 1968 case BinaryOperator::Or: 1969 case BinaryOperator::LAnd: 1970 case BinaryOperator::LOr: 1971 case BinaryOperator::Assign: 1972 case BinaryOperator::Comma: 1973 assert(false && "Not valid compound assignment operators"); 1974 break; 1975 } 1976 1977 llvm_unreachable("Unhandled compound assignment operator"); 1978} 1979