CGExprScalar.cpp revision 85b4521e34dcd4a0a4a1f0819e1123128e5a3125
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 73 Value *EmitLoadOfLValue(LValue LV, QualType T) { 74 return CGF.EmitLoadOfLValue(LV, T).getScalarVal(); 75 } 76 77 /// EmitLoadOfLValue - Given an expression with complex type that represents a 78 /// value l-value, this method emits the address of the l-value, then loads 79 /// and returns the result. 80 Value *EmitLoadOfLValue(const Expr *E) { 81 return EmitLoadOfLValue(EmitLValue(E), E->getType()); 82 } 83 84 /// EmitConversionToBool - Convert the specified expression value to a 85 /// boolean (i1) truth value. This is equivalent to "Val != 0". 86 Value *EmitConversionToBool(Value *Src, QualType DstTy); 87 88 /// EmitScalarConversion - Emit a conversion from the specified type to the 89 /// specified destination type, both of which are LLVM scalar types. 90 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); 91 92 /// EmitComplexToScalarConversion - Emit a conversion from the specified 93 /// complex type to the specified destination type, where the destination type 94 /// is an LLVM scalar type. 95 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 96 QualType SrcTy, QualType DstTy); 97 98 //===--------------------------------------------------------------------===// 99 // Visitor Methods 100 //===--------------------------------------------------------------------===// 101 102 Value *VisitStmt(Stmt *S) { 103 S->dump(CGF.getContext().getSourceManager()); 104 assert(0 && "Stmt can't have complex result type!"); 105 return 0; 106 } 107 Value *VisitExpr(Expr *S); 108 109 Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); } 110 111 // Leaves. 112 Value *VisitIntegerLiteral(const IntegerLiteral *E) { 113 return llvm::ConstantInt::get(VMContext, E->getValue()); 114 } 115 Value *VisitFloatingLiteral(const FloatingLiteral *E) { 116 return llvm::ConstantFP::get(VMContext, E->getValue()); 117 } 118 Value *VisitCharacterLiteral(const CharacterLiteral *E) { 119 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 120 } 121 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 122 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 123 } 124 Value *VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) { 125 return llvm::Constant::getNullValue(ConvertType(E->getType())); 126 } 127 Value *VisitGNUNullExpr(const GNUNullExpr *E) { 128 return llvm::Constant::getNullValue(ConvertType(E->getType())); 129 } 130 Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { 131 return llvm::ConstantInt::get(ConvertType(E->getType()), 132 CGF.getContext().typesAreCompatible( 133 E->getArgType1(), E->getArgType2())); 134 } 135 Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); 136 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 137 llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel()); 138 return Builder.CreateBitCast(V, ConvertType(E->getType())); 139 } 140 141 // l-values. 142 Value *VisitDeclRefExpr(DeclRefExpr *E) { 143 Expr::EvalResult Result; 144 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 145 assert(!Result.HasSideEffects && "Constant declref with side-effect?!"); 146 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 147 } 148 return EmitLoadOfLValue(E); 149 } 150 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 151 return CGF.EmitObjCSelectorExpr(E); 152 } 153 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 154 return CGF.EmitObjCProtocolExpr(E); 155 } 156 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 157 return EmitLoadOfLValue(E); 158 } 159 Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { 160 return EmitLoadOfLValue(E); 161 } 162 Value *VisitObjCImplicitSetterGetterRefExpr( 163 ObjCImplicitSetterGetterRefExpr *E) { 164 return EmitLoadOfLValue(E); 165 } 166 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 167 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 168 } 169 170 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 171 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 172 Value *VisitMemberExpr(MemberExpr *E); 173 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 174 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 175 return EmitLoadOfLValue(E); 176 } 177 Value *VisitStringLiteral(Expr *E) { return EmitLValue(E).getAddress(); } 178 Value *VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { 179 return EmitLValue(E).getAddress(); 180 } 181 182 Value *VisitPredefinedExpr(Expr *E) { return EmitLValue(E).getAddress(); } 183 184 Value *VisitInitListExpr(InitListExpr *E); 185 186 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { 187 return llvm::Constant::getNullValue(ConvertType(E->getType())); 188 } 189 Value *VisitCastExpr(CastExpr *E) { 190 // Make sure to evaluate VLA bounds now so that we have them for later. 191 if (E->getType()->isVariablyModifiedType()) 192 CGF.EmitVLASize(E->getType()); 193 194 return EmitCastExpr(E); 195 } 196 Value *EmitCastExpr(CastExpr *E); 197 198 Value *VisitCallExpr(const CallExpr *E) { 199 if (E->getCallReturnType()->isReferenceType()) 200 return EmitLoadOfLValue(E); 201 202 return CGF.EmitCallExpr(E).getScalarVal(); 203 } 204 205 Value *VisitStmtExpr(const StmtExpr *E); 206 207 Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E); 208 209 // Unary Operators. 210 Value *VisitPrePostIncDec(const UnaryOperator *E, bool isInc, bool isPre); 211 Value *VisitUnaryPostDec(const UnaryOperator *E) { 212 return VisitPrePostIncDec(E, false, false); 213 } 214 Value *VisitUnaryPostInc(const UnaryOperator *E) { 215 return VisitPrePostIncDec(E, true, false); 216 } 217 Value *VisitUnaryPreDec(const UnaryOperator *E) { 218 return VisitPrePostIncDec(E, false, true); 219 } 220 Value *VisitUnaryPreInc(const UnaryOperator *E) { 221 return VisitPrePostIncDec(E, true, true); 222 } 223 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 224 return EmitLValue(E->getSubExpr()).getAddress(); 225 } 226 Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } 227 Value *VisitUnaryPlus(const UnaryOperator *E) { 228 // This differs from gcc, though, most likely due to a bug in gcc. 229 TestAndClearIgnoreResultAssign(); 230 return Visit(E->getSubExpr()); 231 } 232 Value *VisitUnaryMinus (const UnaryOperator *E); 233 Value *VisitUnaryNot (const UnaryOperator *E); 234 Value *VisitUnaryLNot (const UnaryOperator *E); 235 Value *VisitUnaryReal (const UnaryOperator *E); 236 Value *VisitUnaryImag (const UnaryOperator *E); 237 Value *VisitUnaryExtension(const UnaryOperator *E) { 238 return Visit(E->getSubExpr()); 239 } 240 Value *VisitUnaryOffsetOf(const UnaryOperator *E); 241 242 // C++ 243 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 244 return Visit(DAE->getExpr()); 245 } 246 Value *VisitCXXThisExpr(CXXThisExpr *TE) { 247 return CGF.LoadCXXThis(); 248 } 249 250 Value *VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) { 251 return CGF.EmitCXXExprWithTemporaries(E).getScalarVal(); 252 } 253 Value *VisitCXXNewExpr(const CXXNewExpr *E) { 254 return CGF.EmitCXXNewExpr(E); 255 } 256 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { 257 CGF.EmitCXXDeleteExpr(E); 258 return 0; 259 } 260 261 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { 262 // C++ [expr.pseudo]p1: 263 // The result shall only be used as the operand for the function call 264 // operator (), and the result of such a call has type void. The only 265 // effect is the evaluation of the postfix-expression before the dot or 266 // arrow. 267 CGF.EmitScalarExpr(E->getBase()); 268 return 0; 269 } 270 271 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { 272 return llvm::Constant::getNullValue(ConvertType(E->getType())); 273 } 274 275 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { 276 CGF.EmitCXXThrowExpr(E); 277 return 0; 278 } 279 280 // Binary Operators. 281 Value *EmitMul(const BinOpInfo &Ops) { 282 if (CGF.getContext().getLangOptions().OverflowChecking 283 && Ops.Ty->isSignedIntegerType()) 284 return EmitOverflowCheckedBinOp(Ops); 285 if (Ops.LHS->getType()->isFPOrFPVector()) 286 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 287 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 288 } 289 /// Create a binary op that checks for overflow. 290 /// Currently only supports +, - and *. 291 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 292 Value *EmitDiv(const BinOpInfo &Ops); 293 Value *EmitRem(const BinOpInfo &Ops); 294 Value *EmitAdd(const BinOpInfo &Ops); 295 Value *EmitSub(const BinOpInfo &Ops); 296 Value *EmitShl(const BinOpInfo &Ops); 297 Value *EmitShr(const BinOpInfo &Ops); 298 Value *EmitAnd(const BinOpInfo &Ops) { 299 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 300 } 301 Value *EmitXor(const BinOpInfo &Ops) { 302 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 303 } 304 Value *EmitOr (const BinOpInfo &Ops) { 305 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 306 } 307 308 BinOpInfo EmitBinOps(const BinaryOperator *E); 309 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 310 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 311 312 // Binary operators and binary compound assignment operators. 313#define HANDLEBINOP(OP) \ 314 Value *VisitBin ## OP(const BinaryOperator *E) { \ 315 return Emit ## OP(EmitBinOps(E)); \ 316 } \ 317 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 318 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 319 } 320 HANDLEBINOP(Mul); 321 HANDLEBINOP(Div); 322 HANDLEBINOP(Rem); 323 HANDLEBINOP(Add); 324 HANDLEBINOP(Sub); 325 HANDLEBINOP(Shl); 326 HANDLEBINOP(Shr); 327 HANDLEBINOP(And); 328 HANDLEBINOP(Xor); 329 HANDLEBINOP(Or); 330#undef HANDLEBINOP 331 332 // Comparisons. 333 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 334 unsigned SICmpOpc, unsigned FCmpOpc); 335#define VISITCOMP(CODE, UI, SI, FP) \ 336 Value *VisitBin##CODE(const BinaryOperator *E) { \ 337 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 338 llvm::FCmpInst::FP); } 339 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT); 340 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT); 341 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE); 342 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE); 343 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ); 344 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE); 345#undef VISITCOMP 346 347 Value *VisitBinAssign (const BinaryOperator *E); 348 349 Value *VisitBinLAnd (const BinaryOperator *E); 350 Value *VisitBinLOr (const BinaryOperator *E); 351 Value *VisitBinComma (const BinaryOperator *E); 352 353 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } 354 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); } 355 356 // Other Operators. 357 Value *VisitBlockExpr(const BlockExpr *BE); 358 Value *VisitConditionalOperator(const ConditionalOperator *CO); 359 Value *VisitChooseExpr(ChooseExpr *CE); 360 Value *VisitVAArgExpr(VAArgExpr *VE); 361 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 362 return CGF.EmitObjCStringLiteral(E); 363 } 364}; 365} // end anonymous namespace. 366 367//===----------------------------------------------------------------------===// 368// Utilities 369//===----------------------------------------------------------------------===// 370 371/// EmitConversionToBool - Convert the specified expression value to a 372/// boolean (i1) truth value. This is equivalent to "Val != 0". 373Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 374 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs"); 375 376 if (SrcType->isRealFloatingType()) { 377 // Compare against 0.0 for fp scalars. 378 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 379 return Builder.CreateFCmpUNE(Src, Zero, "tobool"); 380 } 381 382 if (SrcType->isMemberPointerType()) { 383 // FIXME: This is ABI specific. 384 385 // Compare against -1. 386 llvm::Value *NegativeOne = llvm::Constant::getAllOnesValue(Src->getType()); 387 return Builder.CreateICmpNE(Src, NegativeOne, "tobool"); 388 } 389 390 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 391 "Unknown scalar type to convert"); 392 393 // Because of the type rules of C, we often end up computing a logical value, 394 // then zero extending it to int, then wanting it as a logical value again. 395 // Optimize this common case. 396 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) { 397 if (ZI->getOperand(0)->getType() == 398 llvm::Type::getInt1Ty(CGF.getLLVMContext())) { 399 Value *Result = ZI->getOperand(0); 400 // If there aren't any more uses, zap the instruction to save space. 401 // Note that there can be more uses, for example if this 402 // is the result of an assignment. 403 if (ZI->use_empty()) 404 ZI->eraseFromParent(); 405 return Result; 406 } 407 } 408 409 // Compare against an integer or pointer null. 410 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 411 return Builder.CreateICmpNE(Src, Zero, "tobool"); 412} 413 414/// EmitScalarConversion - Emit a conversion from the specified type to the 415/// specified destination type, both of which are LLVM scalar types. 416Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 417 QualType DstType) { 418 SrcType = CGF.getContext().getCanonicalType(SrcType); 419 DstType = CGF.getContext().getCanonicalType(DstType); 420 if (SrcType == DstType) return Src; 421 422 if (DstType->isVoidType()) return 0; 423 424 llvm::LLVMContext &VMContext = CGF.getLLVMContext(); 425 426 // Handle conversions to bool first, they are special: comparisons against 0. 427 if (DstType->isBooleanType()) 428 return EmitConversionToBool(Src, SrcType); 429 430 const llvm::Type *DstTy = ConvertType(DstType); 431 432 // Ignore conversions like int -> uint. 433 if (Src->getType() == DstTy) 434 return Src; 435 436 // Handle pointer conversions next: pointers can only be converted to/from 437 // other pointers and integers. Check for pointer types in terms of LLVM, as 438 // some native types (like Obj-C id) may map to a pointer type. 439 if (isa<llvm::PointerType>(DstTy)) { 440 // The source value may be an integer, or a pointer. 441 if (isa<llvm::PointerType>(Src->getType())) 442 return Builder.CreateBitCast(Src, DstTy, "conv"); 443 444 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 445 // First, convert to the correct width so that we control the kind of 446 // extension. 447 const llvm::Type *MiddleTy = 448 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 449 bool InputSigned = SrcType->isSignedIntegerType(); 450 llvm::Value* IntResult = 451 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 452 // Then, cast to pointer. 453 return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); 454 } 455 456 if (isa<llvm::PointerType>(Src->getType())) { 457 // Must be an ptr to int cast. 458 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 459 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 460 } 461 462 // A scalar can be splatted to an extended vector of the same element type 463 if (DstType->isExtVectorType() && !SrcType->isVectorType()) { 464 // Cast the scalar to element type 465 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType(); 466 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 467 468 // Insert the element in element zero of an undef vector 469 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 470 llvm::Value *Idx = 471 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0); 472 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 473 474 // Splat the element across to all elements 475 llvm::SmallVector<llvm::Constant*, 16> Args; 476 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 477 for (unsigned i = 0; i < NumElements; i++) 478 Args.push_back(llvm::ConstantInt::get( 479 llvm::Type::getInt32Ty(VMContext), 0)); 480 481 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 482 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 483 return Yay; 484 } 485 486 // Allow bitcast from vector to integer/fp of the same size. 487 if (isa<llvm::VectorType>(Src->getType()) || 488 isa<llvm::VectorType>(DstTy)) 489 return Builder.CreateBitCast(Src, DstTy, "conv"); 490 491 // Finally, we have the arithmetic types: real int/float. 492 if (isa<llvm::IntegerType>(Src->getType())) { 493 bool InputSigned = SrcType->isSignedIntegerType(); 494 if (isa<llvm::IntegerType>(DstTy)) 495 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 496 else if (InputSigned) 497 return Builder.CreateSIToFP(Src, DstTy, "conv"); 498 else 499 return Builder.CreateUIToFP(Src, DstTy, "conv"); 500 } 501 502 assert(Src->getType()->isFloatingPoint() && "Unknown real conversion"); 503 if (isa<llvm::IntegerType>(DstTy)) { 504 if (DstType->isSignedIntegerType()) 505 return Builder.CreateFPToSI(Src, DstTy, "conv"); 506 else 507 return Builder.CreateFPToUI(Src, DstTy, "conv"); 508 } 509 510 assert(DstTy->isFloatingPoint() && "Unknown real conversion"); 511 if (DstTy->getTypeID() < Src->getType()->getTypeID()) 512 return Builder.CreateFPTrunc(Src, DstTy, "conv"); 513 else 514 return Builder.CreateFPExt(Src, DstTy, "conv"); 515} 516 517/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 518/// type to the specified destination type, where the destination type is an 519/// LLVM scalar type. 520Value *ScalarExprEmitter:: 521EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 522 QualType SrcTy, QualType DstTy) { 523 // Get the source element type. 524 SrcTy = SrcTy->getAs<ComplexType>()->getElementType(); 525 526 // Handle conversions to bool first, they are special: comparisons against 0. 527 if (DstTy->isBooleanType()) { 528 // Complex != 0 -> (Real != 0) | (Imag != 0) 529 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 530 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 531 return Builder.CreateOr(Src.first, Src.second, "tobool"); 532 } 533 534 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 535 // the imaginary part of the complex value is discarded and the value of the 536 // real part is converted according to the conversion rules for the 537 // corresponding real type. 538 return EmitScalarConversion(Src.first, SrcTy, DstTy); 539} 540 541 542//===----------------------------------------------------------------------===// 543// Visitor Methods 544//===----------------------------------------------------------------------===// 545 546Value *ScalarExprEmitter::VisitExpr(Expr *E) { 547 CGF.ErrorUnsupported(E, "scalar expression"); 548 if (E->getType()->isVoidType()) 549 return 0; 550 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 551} 552 553Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 554 llvm::SmallVector<llvm::Constant*, 32> indices; 555 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 556 indices.push_back(cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i)))); 557 } 558 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 559 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 560 Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); 561 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 562} 563Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { 564 Expr::EvalResult Result; 565 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 566 if (E->isArrow()) 567 CGF.EmitScalarExpr(E->getBase()); 568 else 569 EmitLValue(E->getBase()); 570 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 571 } 572 return EmitLoadOfLValue(E); 573} 574 575Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 576 TestAndClearIgnoreResultAssign(); 577 578 // Emit subscript expressions in rvalue context's. For most cases, this just 579 // loads the lvalue formed by the subscript expr. However, we have to be 580 // careful, because the base of a vector subscript is occasionally an rvalue, 581 // so we can't get it as an lvalue. 582 if (!E->getBase()->getType()->isVectorType()) 583 return EmitLoadOfLValue(E); 584 585 // Handle the vector case. The base must be a vector, the index must be an 586 // integer value. 587 Value *Base = Visit(E->getBase()); 588 Value *Idx = Visit(E->getIdx()); 589 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerType(); 590 Idx = Builder.CreateIntCast(Idx, 591 llvm::Type::getInt32Ty(CGF.getLLVMContext()), 592 IdxSigned, 593 "vecidxcast"); 594 return Builder.CreateExtractElement(Base, Idx, "vecext"); 595} 596 597static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, 598 unsigned Off, const llvm::Type *I32Ty) { 599 int MV = SVI->getMaskValue(Idx); 600 if (MV == -1) 601 return llvm::UndefValue::get(I32Ty); 602 return llvm::ConstantInt::get(I32Ty, Off+MV); 603} 604 605Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) { 606 bool Ignore = TestAndClearIgnoreResultAssign(); 607 (void)Ignore; 608 assert (Ignore == false && "init list ignored"); 609 unsigned NumInitElements = E->getNumInits(); 610 611 if (E->hadArrayRangeDesignator()) 612 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 613 614 const llvm::VectorType *VType = 615 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 616 617 // We have a scalar in braces. Just use the first element. 618 if (!VType) 619 return Visit(E->getInit(0)); 620 621 unsigned ResElts = VType->getNumElements(); 622 const llvm::Type *I32Ty = llvm::Type::getInt32Ty(CGF.getLLVMContext()); 623 624 // Loop over initializers collecting the Value for each, and remembering 625 // whether the source was swizzle (ExtVectorElementExpr). This will allow 626 // us to fold the shuffle for the swizzle into the shuffle for the vector 627 // initializer, since LLVM optimizers generally do not want to touch 628 // shuffles. 629 unsigned CurIdx = 0; 630 bool VIsUndefShuffle = false; 631 llvm::Value *V = llvm::UndefValue::get(VType); 632 for (unsigned i = 0; i != NumInitElements; ++i) { 633 Expr *IE = E->getInit(i); 634 Value *Init = Visit(IE); 635 llvm::SmallVector<llvm::Constant*, 16> Args; 636 637 const llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType()); 638 639 // Handle scalar elements. If the scalar initializer is actually one 640 // element of a different vector of the same width, use shuffle instead of 641 // extract+insert. 642 if (!VVT) { 643 if (isa<ExtVectorElementExpr>(IE)) { 644 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init); 645 646 if (EI->getVectorOperandType()->getNumElements() == ResElts) { 647 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand()); 648 Value *LHS = 0, *RHS = 0; 649 if (CurIdx == 0) { 650 // insert into undef -> shuffle (src, undef) 651 Args.push_back(C); 652 for (unsigned j = 1; j != ResElts; ++j) 653 Args.push_back(llvm::UndefValue::get(I32Ty)); 654 655 LHS = EI->getVectorOperand(); 656 RHS = V; 657 VIsUndefShuffle = true; 658 } else if (VIsUndefShuffle) { 659 // insert into undefshuffle && size match -> shuffle (v, src) 660 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V); 661 for (unsigned j = 0; j != CurIdx; ++j) 662 Args.push_back(getMaskElt(SVV, j, 0, I32Ty)); 663 Args.push_back(llvm::ConstantInt::get(I32Ty, 664 ResElts + C->getZExtValue())); 665 for (unsigned j = CurIdx + 1; j != ResElts; ++j) 666 Args.push_back(llvm::UndefValue::get(I32Ty)); 667 668 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 669 RHS = EI->getVectorOperand(); 670 VIsUndefShuffle = false; 671 } 672 if (!Args.empty()) { 673 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 674 V = Builder.CreateShuffleVector(LHS, RHS, Mask); 675 ++CurIdx; 676 continue; 677 } 678 } 679 } 680 Value *Idx = llvm::ConstantInt::get(I32Ty, CurIdx); 681 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 682 VIsUndefShuffle = false; 683 ++CurIdx; 684 continue; 685 } 686 687 unsigned InitElts = VVT->getNumElements(); 688 689 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's 690 // input is the same width as the vector being constructed, generate an 691 // optimized shuffle of the swizzle input into the result. 692 unsigned Offset = (CurIdx == 0) ? 0 : ResElts; 693 if (isa<ExtVectorElementExpr>(IE)) { 694 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init); 695 Value *SVOp = SVI->getOperand(0); 696 const llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType()); 697 698 if (OpTy->getNumElements() == ResElts) { 699 for (unsigned j = 0; j != CurIdx; ++j) { 700 // If the current vector initializer is a shuffle with undef, merge 701 // this shuffle directly into it. 702 if (VIsUndefShuffle) { 703 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0, 704 I32Ty)); 705 } else { 706 Args.push_back(llvm::ConstantInt::get(I32Ty, j)); 707 } 708 } 709 for (unsigned j = 0, je = InitElts; j != je; ++j) 710 Args.push_back(getMaskElt(SVI, j, Offset, I32Ty)); 711 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 712 Args.push_back(llvm::UndefValue::get(I32Ty)); 713 714 if (VIsUndefShuffle) 715 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 716 717 Init = SVOp; 718 } 719 } 720 721 // Extend init to result vector length, and then shuffle its contribution 722 // to the vector initializer into V. 723 if (Args.empty()) { 724 for (unsigned j = 0; j != InitElts; ++j) 725 Args.push_back(llvm::ConstantInt::get(I32Ty, j)); 726 for (unsigned j = InitElts; j != ResElts; ++j) 727 Args.push_back(llvm::UndefValue::get(I32Ty)); 728 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 729 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), 730 Mask, "vext"); 731 732 Args.clear(); 733 for (unsigned j = 0; j != CurIdx; ++j) 734 Args.push_back(llvm::ConstantInt::get(I32Ty, j)); 735 for (unsigned j = 0; j != InitElts; ++j) 736 Args.push_back(llvm::ConstantInt::get(I32Ty, j+Offset)); 737 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 738 Args.push_back(llvm::UndefValue::get(I32Ty)); 739 } 740 741 // If V is undef, make sure it ends up on the RHS of the shuffle to aid 742 // merging subsequent shuffles into this one. 743 if (CurIdx == 0) 744 std::swap(V, Init); 745 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 746 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); 747 VIsUndefShuffle = isa<llvm::UndefValue>(Init); 748 CurIdx += InitElts; 749 } 750 751 // FIXME: evaluate codegen vs. shuffling against constant null vector. 752 // Emit remaining default initializers. 753 const llvm::Type *EltTy = VType->getElementType(); 754 755 // Emit remaining default initializers 756 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { 757 Value *Idx = llvm::ConstantInt::get(I32Ty, CurIdx); 758 llvm::Value *Init = llvm::Constant::getNullValue(EltTy); 759 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 760 } 761 return V; 762} 763 764static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { 765 const Expr *E = CE->getSubExpr(); 766 767 if (isa<CXXThisExpr>(E)) { 768 // We always assume that 'this' is never null. 769 return false; 770 } 771 772 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { 773 // And that lvalue casts are never null. 774 if (ICE->isLvalueCast()) 775 return false; 776 } 777 778 return true; 779} 780 781// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 782// have to handle a more broad range of conversions than explicit casts, as they 783// handle things like function to ptr-to-function decay etc. 784Value *ScalarExprEmitter::EmitCastExpr(CastExpr *CE) { 785 Expr *E = CE->getSubExpr(); 786 QualType DestTy = CE->getType(); 787 CastExpr::CastKind Kind = CE->getCastKind(); 788 789 if (!DestTy->isVoidType()) 790 TestAndClearIgnoreResultAssign(); 791 792 // Since almost all cast kinds apply to scalars, this switch doesn't have 793 // a default case, so the compiler will warn on a missing case. The cases 794 // are in the same order as in the CastKind enum. 795 switch (Kind) { 796 case CastExpr::CK_Unknown: 797 // FIXME: All casts should have a known kind! 798 //assert(0 && "Unknown cast kind!"); 799 break; 800 801 case CastExpr::CK_BitCast: { 802 Value *Src = Visit(const_cast<Expr*>(E)); 803 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 804 } 805 case CastExpr::CK_NoOp: 806 return Visit(const_cast<Expr*>(E)); 807 808 case CastExpr::CK_BaseToDerived: { 809 const CXXRecordDecl *BaseClassDecl = 810 E->getType()->getCXXRecordDeclForPointerType(); 811 const CXXRecordDecl *DerivedClassDecl = 812 DestTy->getCXXRecordDeclForPointerType(); 813 814 Value *Src = Visit(const_cast<Expr*>(E)); 815 816 bool NullCheckValue = ShouldNullCheckClassCastValue(CE); 817 return CGF.GetAddressOfDerivedClass(Src, BaseClassDecl, DerivedClassDecl, 818 NullCheckValue); 819 } 820 case CastExpr::CK_DerivedToBase: { 821 const RecordType *DerivedClassTy = 822 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 823 CXXRecordDecl *DerivedClassDecl = 824 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 825 826 const RecordType *BaseClassTy = 827 DestTy->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 828 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseClassTy->getDecl()); 829 830 Value *Src = Visit(const_cast<Expr*>(E)); 831 832 bool NullCheckValue = ShouldNullCheckClassCastValue(CE); 833 return CGF.GetAddressOfBaseClass(Src, DerivedClassDecl, BaseClassDecl, 834 NullCheckValue); 835 } 836 case CastExpr::CK_Dynamic: { 837 Value *V = Visit(const_cast<Expr*>(E)); 838 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 839 return CGF.EmitDynamicCast(V, DCE); 840 } 841 case CastExpr::CK_ToUnion: 842 assert(0 && "Should be unreachable!"); 843 break; 844 845 case CastExpr::CK_ArrayToPointerDecay: { 846 assert(E->getType()->isArrayType() && 847 "Array to pointer decay must have array source type!"); 848 849 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 850 851 // Note that VLA pointers are always decayed, so we don't need to do 852 // anything here. 853 if (!E->getType()->isVariableArrayType()) { 854 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 855 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 856 ->getElementType()) && 857 "Expected pointer to array"); 858 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 859 } 860 861 return V; 862 } 863 case CastExpr::CK_FunctionToPointerDecay: 864 return EmitLValue(E).getAddress(); 865 866 case CastExpr::CK_NullToMemberPointer: 867 return CGF.CGM.EmitNullConstant(DestTy); 868 869 case CastExpr::CK_BaseToDerivedMemberPointer: 870 case CastExpr::CK_DerivedToBaseMemberPointer: { 871 Value *Src = Visit(E); 872 873 // See if we need to adjust the pointer. 874 const CXXRecordDecl *BaseDecl = 875 cast<CXXRecordDecl>(E->getType()->getAs<MemberPointerType>()-> 876 getClass()->getAs<RecordType>()->getDecl()); 877 const CXXRecordDecl *DerivedDecl = 878 cast<CXXRecordDecl>(CE->getType()->getAs<MemberPointerType>()-> 879 getClass()->getAs<RecordType>()->getDecl()); 880 if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) 881 std::swap(DerivedDecl, BaseDecl); 882 883 llvm::Constant *Adj = CGF.CGM.GetCXXBaseClassOffset(DerivedDecl, BaseDecl); 884 if (Adj) { 885 if (CE->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) 886 Src = Builder.CreateSub(Src, Adj, "adj"); 887 else 888 Src = Builder.CreateAdd(Src, Adj, "adj"); 889 } 890 return Src; 891 } 892 893 case CastExpr::CK_UserDefinedConversion: 894 case CastExpr::CK_ConstructorConversion: 895 assert(0 && "Should be unreachable!"); 896 break; 897 898 case CastExpr::CK_IntegralToPointer: { 899 Value *Src = Visit(const_cast<Expr*>(E)); 900 901 // First, convert to the correct width so that we control the kind of 902 // extension. 903 const llvm::Type *MiddleTy = 904 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 905 bool InputSigned = E->getType()->isSignedIntegerType(); 906 llvm::Value* IntResult = 907 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 908 909 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 910 } 911 case CastExpr::CK_PointerToIntegral: { 912 Value *Src = Visit(const_cast<Expr*>(E)); 913 return Builder.CreatePtrToInt(Src, ConvertType(DestTy)); 914 } 915 case CastExpr::CK_ToVoid: { 916 CGF.EmitAnyExpr(E, 0, false, true); 917 return 0; 918 } 919 case CastExpr::CK_VectorSplat: { 920 const llvm::Type *DstTy = ConvertType(DestTy); 921 Value *Elt = Visit(const_cast<Expr*>(E)); 922 923 // Insert the element in element zero of an undef vector 924 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 925 llvm::Value *Idx = 926 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 0); 927 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 928 929 // Splat the element across to all elements 930 llvm::SmallVector<llvm::Constant*, 16> Args; 931 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 932 for (unsigned i = 0; i < NumElements; i++) 933 Args.push_back(llvm::ConstantInt::get( 934 llvm::Type::getInt32Ty(VMContext), 0)); 935 936 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 937 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 938 return Yay; 939 } 940 case CastExpr::CK_IntegralCast: 941 case CastExpr::CK_IntegralToFloating: 942 case CastExpr::CK_FloatingToIntegral: 943 case CastExpr::CK_FloatingCast: 944 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 945 946 case CastExpr::CK_MemberPointerToBoolean: { 947 const MemberPointerType* T = E->getType()->getAs<MemberPointerType>(); 948 949 if (T->getPointeeType()->isFunctionType()) { 950 // We have a member function pointer. 951 llvm::Value *Ptr = CGF.CreateTempAlloca(ConvertType(E->getType())); 952 953 CGF.EmitAggExpr(E, Ptr, /*VolatileDest=*/false); 954 955 // Get the pointer. 956 llvm::Value *FuncPtr = Builder.CreateStructGEP(Ptr, 0, "src.ptr"); 957 FuncPtr = Builder.CreateLoad(FuncPtr); 958 959 llvm::Value *IsNotNull = 960 Builder.CreateICmpNE(FuncPtr, 961 llvm::Constant::getNullValue(FuncPtr->getType()), 962 "tobool"); 963 964 return IsNotNull; 965 } 966 967 // We have a regular member pointer. 968 Value *Ptr = Visit(const_cast<Expr*>(E)); 969 llvm::Value *IsNotNull = 970 Builder.CreateICmpNE(Ptr, CGF.CGM.EmitNullConstant(E->getType()), 971 "tobool"); 972 return IsNotNull; 973 } 974 } 975 976 // Handle cases where the source is an non-complex type. 977 978 if (!CGF.hasAggregateLLVMType(E->getType())) { 979 Value *Src = Visit(const_cast<Expr*>(E)); 980 981 // Use EmitScalarConversion to perform the conversion. 982 return EmitScalarConversion(Src, E->getType(), DestTy); 983 } 984 985 if (E->getType()->isAnyComplexType()) { 986 // Handle cases where the source is a complex type. 987 bool IgnoreImag = true; 988 bool IgnoreImagAssign = true; 989 bool IgnoreReal = IgnoreResultAssign; 990 bool IgnoreRealAssign = IgnoreResultAssign; 991 if (DestTy->isBooleanType()) 992 IgnoreImagAssign = IgnoreImag = false; 993 else if (DestTy->isVoidType()) { 994 IgnoreReal = IgnoreImag = false; 995 IgnoreRealAssign = IgnoreImagAssign = true; 996 } 997 CodeGenFunction::ComplexPairTy V 998 = CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign, 999 IgnoreImagAssign); 1000 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 1001 } 1002 1003 // Okay, this is a cast from an aggregate. It must be a cast to void. Just 1004 // evaluate the result and return. 1005 CGF.EmitAggExpr(E, 0, false, true); 1006 return 0; 1007} 1008 1009Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 1010 return CGF.EmitCompoundStmt(*E->getSubStmt(), 1011 !E->getType()->isVoidType()).getScalarVal(); 1012} 1013 1014Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 1015 llvm::Value *V = CGF.GetAddrOfBlockDecl(E); 1016 if (E->getType().isObjCGCWeak()) 1017 return CGF.CGM.getObjCRuntime().EmitObjCWeakRead(CGF, V); 1018 return Builder.CreateLoad(V, false, "tmp"); 1019} 1020 1021//===----------------------------------------------------------------------===// 1022// Unary Operators 1023//===----------------------------------------------------------------------===// 1024 1025Value *ScalarExprEmitter::VisitPrePostIncDec(const UnaryOperator *E, 1026 bool isInc, bool isPre) { 1027 LValue LV = EmitLValue(E->getSubExpr()); 1028 QualType ValTy = E->getSubExpr()->getType(); 1029 Value *InVal = CGF.EmitLoadOfLValue(LV, ValTy).getScalarVal(); 1030 1031 llvm::LLVMContext &VMContext = CGF.getLLVMContext(); 1032 1033 int AmountVal = isInc ? 1 : -1; 1034 1035 if (ValTy->isPointerType() && 1036 ValTy->getAs<PointerType>()->isVariableArrayType()) { 1037 // The amount of the addition/subtraction needs to account for the VLA size 1038 CGF.ErrorUnsupported(E, "VLA pointer inc/dec"); 1039 } 1040 1041 Value *NextVal; 1042 if (const llvm::PointerType *PT = 1043 dyn_cast<llvm::PointerType>(InVal->getType())) { 1044 llvm::Constant *Inc = 1045 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), AmountVal); 1046 if (!isa<llvm::FunctionType>(PT->getElementType())) { 1047 QualType PTEE = ValTy->getPointeeType(); 1048 if (const ObjCInterfaceType *OIT = 1049 dyn_cast<ObjCInterfaceType>(PTEE)) { 1050 // Handle interface types, which are not represented with a concrete type. 1051 int size = CGF.getContext().getTypeSize(OIT) / 8; 1052 if (!isInc) 1053 size = -size; 1054 Inc = llvm::ConstantInt::get(Inc->getType(), size); 1055 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1056 InVal = Builder.CreateBitCast(InVal, i8Ty); 1057 NextVal = Builder.CreateGEP(InVal, Inc, "add.ptr"); 1058 llvm::Value *lhs = LV.getAddress(); 1059 lhs = Builder.CreateBitCast(lhs, llvm::PointerType::getUnqual(i8Ty)); 1060 LV = LValue::MakeAddr(lhs, CGF.MakeQualifiers(ValTy)); 1061 } else 1062 NextVal = Builder.CreateInBoundsGEP(InVal, Inc, "ptrincdec"); 1063 } else { 1064 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1065 NextVal = Builder.CreateBitCast(InVal, i8Ty, "tmp"); 1066 NextVal = Builder.CreateGEP(NextVal, Inc, "ptrincdec"); 1067 NextVal = Builder.CreateBitCast(NextVal, InVal->getType()); 1068 } 1069 } else if (InVal->getType() == llvm::Type::getInt1Ty(VMContext) && isInc) { 1070 // Bool++ is an interesting case, due to promotion rules, we get: 1071 // Bool++ -> Bool = Bool+1 -> Bool = (int)Bool+1 -> 1072 // Bool = ((int)Bool+1) != 0 1073 // An interesting aspect of this is that increment is always true. 1074 // Decrement does not have this property. 1075 NextVal = llvm::ConstantInt::getTrue(VMContext); 1076 } else if (isa<llvm::IntegerType>(InVal->getType())) { 1077 NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); 1078 1079 // Signed integer overflow is undefined behavior. 1080 if (ValTy->isSignedIntegerType()) 1081 NextVal = Builder.CreateNSWAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1082 else 1083 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1084 } else { 1085 // Add the inc/dec to the real part. 1086 if (InVal->getType()->isFloatTy()) 1087 NextVal = 1088 llvm::ConstantFP::get(VMContext, 1089 llvm::APFloat(static_cast<float>(AmountVal))); 1090 else if (InVal->getType()->isDoubleTy()) 1091 NextVal = 1092 llvm::ConstantFP::get(VMContext, 1093 llvm::APFloat(static_cast<double>(AmountVal))); 1094 else { 1095 llvm::APFloat F(static_cast<float>(AmountVal)); 1096 bool ignored; 1097 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, 1098 &ignored); 1099 NextVal = llvm::ConstantFP::get(VMContext, F); 1100 } 1101 NextVal = Builder.CreateFAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1102 } 1103 1104 // Store the updated result through the lvalue. 1105 if (LV.isBitfield()) 1106 CGF.EmitStoreThroughBitfieldLValue(RValue::get(NextVal), LV, ValTy, 1107 &NextVal); 1108 else 1109 CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV, ValTy); 1110 1111 // If this is a postinc, return the value read from memory, otherwise use the 1112 // updated value. 1113 return isPre ? NextVal : InVal; 1114} 1115 1116 1117Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1118 TestAndClearIgnoreResultAssign(); 1119 Value *Op = Visit(E->getSubExpr()); 1120 if (Op->getType()->isFPOrFPVector()) 1121 return Builder.CreateFNeg(Op, "neg"); 1122 return Builder.CreateNeg(Op, "neg"); 1123} 1124 1125Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1126 TestAndClearIgnoreResultAssign(); 1127 Value *Op = Visit(E->getSubExpr()); 1128 return Builder.CreateNot(Op, "neg"); 1129} 1130 1131Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1132 // Compare operand to zero. 1133 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1134 1135 // Invert value. 1136 // TODO: Could dynamically modify easy computations here. For example, if 1137 // the operand is an icmp ne, turn into icmp eq. 1138 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1139 1140 // ZExt result to the expr type. 1141 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1142} 1143 1144/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of 1145/// argument of the sizeof expression as an integer. 1146Value * 1147ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { 1148 QualType TypeToSize = E->getTypeOfArgument(); 1149 if (E->isSizeOf()) { 1150 if (const VariableArrayType *VAT = 1151 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1152 if (E->isArgumentType()) { 1153 // sizeof(type) - make sure to emit the VLA size. 1154 CGF.EmitVLASize(TypeToSize); 1155 } else { 1156 // C99 6.5.3.4p2: If the argument is an expression of type 1157 // VLA, it is evaluated. 1158 CGF.EmitAnyExpr(E->getArgumentExpr()); 1159 } 1160 1161 return CGF.GetVLASize(VAT); 1162 } 1163 } 1164 1165 // If this isn't sizeof(vla), the result must be constant; use the constant 1166 // folding logic so we don't have to duplicate it here. 1167 Expr::EvalResult Result; 1168 E->Evaluate(Result, CGF.getContext()); 1169 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 1170} 1171 1172Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1173 Expr *Op = E->getSubExpr(); 1174 if (Op->getType()->isAnyComplexType()) 1175 return CGF.EmitComplexExpr(Op, false, true, false, true).first; 1176 return Visit(Op); 1177} 1178Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1179 Expr *Op = E->getSubExpr(); 1180 if (Op->getType()->isAnyComplexType()) 1181 return CGF.EmitComplexExpr(Op, true, false, true, false).second; 1182 1183 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1184 // effects are evaluated, but not the actual value. 1185 if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) 1186 CGF.EmitLValue(Op); 1187 else 1188 CGF.EmitScalarExpr(Op, true); 1189 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1190} 1191 1192Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) { 1193 Value* ResultAsPtr = EmitLValue(E->getSubExpr()).getAddress(); 1194 const llvm::Type* ResultType = ConvertType(E->getType()); 1195 return Builder.CreatePtrToInt(ResultAsPtr, ResultType, "offsetof"); 1196} 1197 1198//===----------------------------------------------------------------------===// 1199// Binary Operators 1200//===----------------------------------------------------------------------===// 1201 1202BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1203 TestAndClearIgnoreResultAssign(); 1204 BinOpInfo Result; 1205 Result.LHS = Visit(E->getLHS()); 1206 Result.RHS = Visit(E->getRHS()); 1207 Result.Ty = E->getType(); 1208 Result.E = E; 1209 return Result; 1210} 1211 1212Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 1213 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 1214 bool Ignore = TestAndClearIgnoreResultAssign(); 1215 QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType(); 1216 1217 BinOpInfo OpInfo; 1218 1219 if (E->getComputationResultType()->isAnyComplexType()) { 1220 // This needs to go through the complex expression emitter, but it's a tad 1221 // complicated to do that... I'm leaving it out for now. (Note that we do 1222 // actually need the imaginary part of the RHS for multiplication and 1223 // division.) 1224 CGF.ErrorUnsupported(E, "complex compound assignment"); 1225 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 1226 } 1227 1228 // Emit the RHS first. __block variables need to have the rhs evaluated 1229 // first, plus this should improve codegen a little. 1230 OpInfo.RHS = Visit(E->getRHS()); 1231 OpInfo.Ty = E->getComputationResultType(); 1232 OpInfo.E = E; 1233 // Load/convert the LHS. 1234 LValue LHSLV = EmitLValue(E->getLHS()); 1235 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 1236 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 1237 E->getComputationLHSType()); 1238 1239 // Expand the binary operator. 1240 Value *Result = (this->*Func)(OpInfo); 1241 1242 // Convert the result back to the LHS type. 1243 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 1244 1245 // Store the result value into the LHS lvalue. Bit-fields are handled 1246 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 1247 // 'An assignment expression has the value of the left operand after the 1248 // assignment...'. 1249 if (LHSLV.isBitfield()) { 1250 if (!LHSLV.isVolatileQualified()) { 1251 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, 1252 &Result); 1253 return Result; 1254 } else 1255 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy); 1256 } else 1257 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); 1258 if (Ignore) 1259 return 0; 1260 return EmitLoadOfLValue(LHSLV, E->getType()); 1261} 1262 1263 1264Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 1265 if (Ops.LHS->getType()->isFPOrFPVector()) 1266 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 1267 else if (Ops.Ty->isUnsignedIntegerType()) 1268 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 1269 else 1270 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 1271} 1272 1273Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 1274 // Rem in C can't be a floating point type: C99 6.5.5p2. 1275 if (Ops.Ty->isUnsignedIntegerType()) 1276 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 1277 else 1278 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 1279} 1280 1281Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 1282 unsigned IID; 1283 unsigned OpID = 0; 1284 1285 switch (Ops.E->getOpcode()) { 1286 case BinaryOperator::Add: 1287 case BinaryOperator::AddAssign: 1288 OpID = 1; 1289 IID = llvm::Intrinsic::sadd_with_overflow; 1290 break; 1291 case BinaryOperator::Sub: 1292 case BinaryOperator::SubAssign: 1293 OpID = 2; 1294 IID = llvm::Intrinsic::ssub_with_overflow; 1295 break; 1296 case BinaryOperator::Mul: 1297 case BinaryOperator::MulAssign: 1298 OpID = 3; 1299 IID = llvm::Intrinsic::smul_with_overflow; 1300 break; 1301 default: 1302 assert(false && "Unsupported operation for overflow detection"); 1303 IID = 0; 1304 } 1305 OpID <<= 1; 1306 OpID |= 1; 1307 1308 const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1309 1310 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1); 1311 1312 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1313 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1314 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1315 1316 // Branch in case of overflow. 1317 llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); 1318 llvm::BasicBlock *overflowBB = 1319 CGF.createBasicBlock("overflow", CGF.CurFn); 1320 llvm::BasicBlock *continueBB = 1321 CGF.createBasicBlock("overflow.continue", CGF.CurFn); 1322 1323 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1324 1325 // Handle overflow 1326 1327 Builder.SetInsertPoint(overflowBB); 1328 1329 // Handler is: 1330 // long long *__overflow_handler)(long long a, long long b, char op, 1331 // char width) 1332 std::vector<const llvm::Type*> handerArgTypes; 1333 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1334 handerArgTypes.push_back(llvm::Type::getInt64Ty(VMContext)); 1335 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1336 handerArgTypes.push_back(llvm::Type::getInt8Ty(VMContext)); 1337 llvm::FunctionType *handlerTy = llvm::FunctionType::get( 1338 llvm::Type::getInt64Ty(VMContext), handerArgTypes, false); 1339 llvm::Value *handlerFunction = 1340 CGF.CGM.getModule().getOrInsertGlobal("__overflow_handler", 1341 llvm::PointerType::getUnqual(handlerTy)); 1342 handlerFunction = Builder.CreateLoad(handlerFunction); 1343 1344 llvm::Value *handlerResult = Builder.CreateCall4(handlerFunction, 1345 Builder.CreateSExt(Ops.LHS, llvm::Type::getInt64Ty(VMContext)), 1346 Builder.CreateSExt(Ops.RHS, llvm::Type::getInt64Ty(VMContext)), 1347 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), OpID), 1348 llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), 1349 cast<llvm::IntegerType>(opTy)->getBitWidth())); 1350 1351 handlerResult = Builder.CreateTrunc(handlerResult, opTy); 1352 1353 Builder.CreateBr(continueBB); 1354 1355 // Set up the continuation 1356 Builder.SetInsertPoint(continueBB); 1357 // Get the correct result 1358 llvm::PHINode *phi = Builder.CreatePHI(opTy); 1359 phi->reserveOperandSpace(2); 1360 phi->addIncoming(result, initialBB); 1361 phi->addIncoming(handlerResult, overflowBB); 1362 1363 return phi; 1364} 1365 1366Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 1367 if (!Ops.Ty->isAnyPointerType()) { 1368 if (CGF.getContext().getLangOptions().OverflowChecking && 1369 Ops.Ty->isSignedIntegerType()) 1370 return EmitOverflowCheckedBinOp(Ops); 1371 1372 if (Ops.LHS->getType()->isFPOrFPVector()) 1373 return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add"); 1374 1375 // Signed integer overflow is undefined behavior. 1376 if (Ops.Ty->isSignedIntegerType()) 1377 return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add"); 1378 1379 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1380 } 1381 1382 if (Ops.Ty->isPointerType() && 1383 Ops.Ty->getAs<PointerType>()->isVariableArrayType()) { 1384 // The amount of the addition needs to account for the VLA size 1385 CGF.ErrorUnsupported(Ops.E, "VLA pointer addition"); 1386 } 1387 Value *Ptr, *Idx; 1388 Expr *IdxExp; 1389 const PointerType *PT = Ops.E->getLHS()->getType()->getAs<PointerType>(); 1390 const ObjCObjectPointerType *OPT = 1391 Ops.E->getLHS()->getType()->getAs<ObjCObjectPointerType>(); 1392 if (PT || OPT) { 1393 Ptr = Ops.LHS; 1394 Idx = Ops.RHS; 1395 IdxExp = Ops.E->getRHS(); 1396 } else { // int + pointer 1397 PT = Ops.E->getRHS()->getType()->getAs<PointerType>(); 1398 OPT = Ops.E->getRHS()->getType()->getAs<ObjCObjectPointerType>(); 1399 assert((PT || OPT) && "Invalid add expr"); 1400 Ptr = Ops.RHS; 1401 Idx = Ops.LHS; 1402 IdxExp = Ops.E->getLHS(); 1403 } 1404 1405 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1406 if (Width < CGF.LLVMPointerWidth) { 1407 // Zero or sign extend the pointer value based on whether the index is 1408 // signed or not. 1409 const llvm::Type *IdxType = 1410 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1411 if (IdxExp->getType()->isSignedIntegerType()) 1412 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1413 else 1414 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1415 } 1416 const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType(); 1417 // Handle interface types, which are not represented with a concrete type. 1418 if (const ObjCInterfaceType *OIT = dyn_cast<ObjCInterfaceType>(ElementType)) { 1419 llvm::Value *InterfaceSize = 1420 llvm::ConstantInt::get(Idx->getType(), 1421 CGF.getContext().getTypeSize(OIT) / 8); 1422 Idx = Builder.CreateMul(Idx, InterfaceSize); 1423 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1424 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1425 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1426 return Builder.CreateBitCast(Res, Ptr->getType()); 1427 } 1428 1429 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 1430 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 1431 // future proof. 1432 if (ElementType->isVoidType() || ElementType->isFunctionType()) { 1433 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1434 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1435 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1436 return Builder.CreateBitCast(Res, Ptr->getType()); 1437 } 1438 1439 return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr"); 1440} 1441 1442Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 1443 if (!isa<llvm::PointerType>(Ops.LHS->getType())) { 1444 if (CGF.getContext().getLangOptions().OverflowChecking 1445 && Ops.Ty->isSignedIntegerType()) 1446 return EmitOverflowCheckedBinOp(Ops); 1447 1448 if (Ops.LHS->getType()->isFPOrFPVector()) 1449 return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub"); 1450 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1451 } 1452 1453 if (Ops.E->getLHS()->getType()->isPointerType() && 1454 Ops.E->getLHS()->getType()->getAs<PointerType>()->isVariableArrayType()) { 1455 // The amount of the addition needs to account for the VLA size for 1456 // ptr-int 1457 // The amount of the division needs to account for the VLA size for 1458 // ptr-ptr. 1459 CGF.ErrorUnsupported(Ops.E, "VLA pointer subtraction"); 1460 } 1461 1462 const QualType LHSType = Ops.E->getLHS()->getType(); 1463 const QualType LHSElementType = LHSType->getPointeeType(); 1464 if (!isa<llvm::PointerType>(Ops.RHS->getType())) { 1465 // pointer - int 1466 Value *Idx = Ops.RHS; 1467 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1468 if (Width < CGF.LLVMPointerWidth) { 1469 // Zero or sign extend the pointer value based on whether the index is 1470 // signed or not. 1471 const llvm::Type *IdxType = 1472 llvm::IntegerType::get(VMContext, CGF.LLVMPointerWidth); 1473 if (Ops.E->getRHS()->getType()->isSignedIntegerType()) 1474 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1475 else 1476 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1477 } 1478 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); 1479 1480 // Handle interface types, which are not represented with a concrete type. 1481 if (const ObjCInterfaceType *OIT = 1482 dyn_cast<ObjCInterfaceType>(LHSElementType)) { 1483 llvm::Value *InterfaceSize = 1484 llvm::ConstantInt::get(Idx->getType(), 1485 CGF.getContext().getTypeSize(OIT) / 8); 1486 Idx = Builder.CreateMul(Idx, InterfaceSize); 1487 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1488 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1489 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr"); 1490 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1491 } 1492 1493 // Explicitly handle GNU void* and function pointer arithmetic 1494 // extensions. The GNU void* casts amount to no-ops since our void* type is 1495 // i8*, but this is future proof. 1496 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1497 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1498 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1499 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); 1500 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1501 } 1502 1503 return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr"); 1504 } else { 1505 // pointer - pointer 1506 Value *LHS = Ops.LHS; 1507 Value *RHS = Ops.RHS; 1508 1509 uint64_t ElementSize; 1510 1511 // Handle GCC extension for pointer arithmetic on void* and function pointer 1512 // types. 1513 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1514 ElementSize = 1; 1515 } else { 1516 ElementSize = CGF.getContext().getTypeSize(LHSElementType) / 8; 1517 } 1518 1519 const llvm::Type *ResultType = ConvertType(Ops.Ty); 1520 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 1521 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 1522 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 1523 1524 // Optimize out the shift for element size of 1. 1525 if (ElementSize == 1) 1526 return BytesBetween; 1527 1528 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 1529 // pointer difference in C is only defined in the case where both operands 1530 // are pointing to elements of an array. 1531 Value *BytesPerElt = llvm::ConstantInt::get(ResultType, ElementSize); 1532 return Builder.CreateExactSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 1533 } 1534} 1535 1536Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 1537 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1538 // RHS to the same size as the LHS. 1539 Value *RHS = Ops.RHS; 1540 if (Ops.LHS->getType() != RHS->getType()) 1541 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1542 1543 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 1544} 1545 1546Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 1547 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1548 // RHS to the same size as the LHS. 1549 Value *RHS = Ops.RHS; 1550 if (Ops.LHS->getType() != RHS->getType()) 1551 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1552 1553 if (Ops.Ty->isUnsignedIntegerType()) 1554 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 1555 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 1556} 1557 1558Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 1559 unsigned SICmpOpc, unsigned FCmpOpc) { 1560 TestAndClearIgnoreResultAssign(); 1561 Value *Result; 1562 QualType LHSTy = E->getLHS()->getType(); 1563 if (!LHSTy->isAnyComplexType()) { 1564 Value *LHS = Visit(E->getLHS()); 1565 Value *RHS = Visit(E->getRHS()); 1566 1567 if (LHS->getType()->isFPOrFPVector()) { 1568 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 1569 LHS, RHS, "cmp"); 1570 } else if (LHSTy->isSignedIntegerType()) { 1571 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 1572 LHS, RHS, "cmp"); 1573 } else { 1574 // Unsigned integers and pointers. 1575 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1576 LHS, RHS, "cmp"); 1577 } 1578 1579 // If this is a vector comparison, sign extend the result to the appropriate 1580 // vector integer type and return it (don't convert to bool). 1581 if (LHSTy->isVectorType()) 1582 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 1583 1584 } else { 1585 // Complex Comparison: can only be an equality comparison. 1586 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 1587 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 1588 1589 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 1590 1591 Value *ResultR, *ResultI; 1592 if (CETy->isRealFloatingType()) { 1593 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1594 LHS.first, RHS.first, "cmp.r"); 1595 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1596 LHS.second, RHS.second, "cmp.i"); 1597 } else { 1598 // Complex comparisons can only be equality comparisons. As such, signed 1599 // and unsigned opcodes are the same. 1600 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1601 LHS.first, RHS.first, "cmp.r"); 1602 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1603 LHS.second, RHS.second, "cmp.i"); 1604 } 1605 1606 if (E->getOpcode() == BinaryOperator::EQ) { 1607 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 1608 } else { 1609 assert(E->getOpcode() == BinaryOperator::NE && 1610 "Complex comparison other than == or != ?"); 1611 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 1612 } 1613 } 1614 1615 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 1616} 1617 1618Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 1619 bool Ignore = TestAndClearIgnoreResultAssign(); 1620 1621 // __block variables need to have the rhs evaluated first, plus this should 1622 // improve codegen just a little. 1623 Value *RHS = Visit(E->getRHS()); 1624 LValue LHS = EmitLValue(E->getLHS()); 1625 1626 // Store the value into the LHS. Bit-fields are handled specially 1627 // because the result is altered by the store, i.e., [C99 6.5.16p1] 1628 // 'An assignment expression has the value of the left operand after 1629 // the assignment...'. 1630 if (LHS.isBitfield()) { 1631 if (!LHS.isVolatileQualified()) { 1632 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), 1633 &RHS); 1634 return RHS; 1635 } else 1636 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType()); 1637 } else 1638 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 1639 if (Ignore) 1640 return 0; 1641 return EmitLoadOfLValue(LHS, E->getType()); 1642} 1643 1644Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 1645 const llvm::Type *ResTy = ConvertType(E->getType()); 1646 1647 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 1648 // If we have 1 && X, just emit X without inserting the control flow. 1649 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1650 if (Cond == 1) { // If we have 1 && X, just emit X. 1651 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1652 // ZExt result to int or bool. 1653 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 1654 } 1655 1656 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 1657 if (!CGF.ContainsLabel(E->getRHS())) 1658 return llvm::Constant::getNullValue(ResTy); 1659 } 1660 1661 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 1662 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 1663 1664 // Branch on the LHS first. If it is false, go to the failure (cont) block. 1665 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 1666 1667 // Any edges into the ContBlock are now from an (indeterminate number of) 1668 // edges from this first condition. All of these values will be false. Start 1669 // setting up the PHI node in the Cont Block for this. 1670 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1671 "", ContBlock); 1672 PN->reserveOperandSpace(2); // Normal case, two inputs. 1673 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1674 PI != PE; ++PI) 1675 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 1676 1677 CGF.StartConditionalBranch(); 1678 CGF.EmitBlock(RHSBlock); 1679 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1680 CGF.FinishConditionalBranch(); 1681 1682 // Reaquire the RHS block, as there may be subblocks inserted. 1683 RHSBlock = Builder.GetInsertBlock(); 1684 1685 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1686 // into the phi node for the edge with the value of RHSCond. 1687 CGF.EmitBlock(ContBlock); 1688 PN->addIncoming(RHSCond, RHSBlock); 1689 1690 // ZExt result to int. 1691 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); 1692} 1693 1694Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 1695 const llvm::Type *ResTy = ConvertType(E->getType()); 1696 1697 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 1698 // If we have 0 || X, just emit X without inserting the control flow. 1699 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1700 if (Cond == -1) { // If we have 0 || X, just emit X. 1701 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1702 // ZExt result to int or bool. 1703 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 1704 } 1705 1706 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 1707 if (!CGF.ContainsLabel(E->getRHS())) 1708 return llvm::ConstantInt::get(ResTy, 1); 1709 } 1710 1711 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 1712 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 1713 1714 // Branch on the LHS first. If it is true, go to the success (cont) block. 1715 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 1716 1717 // Any edges into the ContBlock are now from an (indeterminate number of) 1718 // edges from this first condition. All of these values will be true. Start 1719 // setting up the PHI node in the Cont Block for this. 1720 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1721 "", ContBlock); 1722 PN->reserveOperandSpace(2); // Normal case, two inputs. 1723 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1724 PI != PE; ++PI) 1725 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 1726 1727 CGF.StartConditionalBranch(); 1728 1729 // Emit the RHS condition as a bool value. 1730 CGF.EmitBlock(RHSBlock); 1731 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1732 1733 CGF.FinishConditionalBranch(); 1734 1735 // Reaquire the RHS block, as there may be subblocks inserted. 1736 RHSBlock = Builder.GetInsertBlock(); 1737 1738 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1739 // into the phi node for the edge with the value of RHSCond. 1740 CGF.EmitBlock(ContBlock); 1741 PN->addIncoming(RHSCond, RHSBlock); 1742 1743 // ZExt result to int. 1744 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 1745} 1746 1747Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 1748 CGF.EmitStmt(E->getLHS()); 1749 CGF.EnsureInsertPoint(); 1750 return Visit(E->getRHS()); 1751} 1752 1753//===----------------------------------------------------------------------===// 1754// Other Operators 1755//===----------------------------------------------------------------------===// 1756 1757/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 1758/// expression is cheap enough and side-effect-free enough to evaluate 1759/// unconditionally instead of conditionally. This is used to convert control 1760/// flow into selects in some cases. 1761static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 1762 CodeGenFunction &CGF) { 1763 if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) 1764 return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr(), CGF); 1765 1766 // TODO: Allow anything we can constant fold to an integer or fp constant. 1767 if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || 1768 isa<FloatingLiteral>(E)) 1769 return true; 1770 1771 // Non-volatile automatic variables too, to get "cond ? X : Y" where 1772 // X and Y are local variables. 1773 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 1774 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 1775 if (VD->hasLocalStorage() && !(CGF.getContext() 1776 .getCanonicalType(VD->getType()) 1777 .isVolatileQualified())) 1778 return true; 1779 1780 return false; 1781} 1782 1783 1784Value *ScalarExprEmitter:: 1785VisitConditionalOperator(const ConditionalOperator *E) { 1786 TestAndClearIgnoreResultAssign(); 1787 // If the condition constant folds and can be elided, try to avoid emitting 1788 // the condition and the dead arm. 1789 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ 1790 Expr *Live = E->getLHS(), *Dead = E->getRHS(); 1791 if (Cond == -1) 1792 std::swap(Live, Dead); 1793 1794 // If the dead side doesn't have labels we need, and if the Live side isn't 1795 // the gnu missing ?: extension (which we could handle, but don't bother 1796 // to), just emit the Live part. 1797 if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part 1798 Live) // Live part isn't missing. 1799 return Visit(Live); 1800 } 1801 1802 1803 // If this is a really simple expression (like x ? 4 : 5), emit this as a 1804 // select instead of as control flow. We can only do this if it is cheap and 1805 // safe to evaluate the LHS and RHS unconditionally. 1806 if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS(), 1807 CGF) && 1808 isCheapEnoughToEvaluateUnconditionally(E->getRHS(), CGF)) { 1809 llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); 1810 llvm::Value *LHS = Visit(E->getLHS()); 1811 llvm::Value *RHS = Visit(E->getRHS()); 1812 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 1813 } 1814 1815 1816 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 1817 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 1818 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 1819 Value *CondVal = 0; 1820 1821 // If we don't have the GNU missing condition extension, emit a branch on bool 1822 // the normal way. 1823 if (E->getLHS()) { 1824 // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for 1825 // the branch on bool. 1826 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); 1827 } else { 1828 // Otherwise, for the ?: extension, evaluate the conditional and then 1829 // convert it to bool the hard way. We do this explicitly because we need 1830 // the unconverted value for the missing middle value of the ?:. 1831 CondVal = CGF.EmitScalarExpr(E->getCond()); 1832 1833 // In some cases, EmitScalarConversion will delete the "CondVal" expression 1834 // if there are no extra uses (an optimization). Inhibit this by making an 1835 // extra dead use, because we're going to add a use of CondVal later. We 1836 // don't use the builder for this, because we don't want it to get optimized 1837 // away. This leaves dead code, but the ?: extension isn't common. 1838 new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", 1839 Builder.GetInsertBlock()); 1840 1841 Value *CondBoolVal = 1842 CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 1843 CGF.getContext().BoolTy); 1844 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 1845 } 1846 1847 CGF.StartConditionalBranch(); 1848 CGF.EmitBlock(LHSBlock); 1849 1850 // Handle the GNU extension for missing LHS. 1851 Value *LHS; 1852 if (E->getLHS()) 1853 LHS = Visit(E->getLHS()); 1854 else // Perform promotions, to handle cases like "short ?: int" 1855 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); 1856 1857 CGF.FinishConditionalBranch(); 1858 LHSBlock = Builder.GetInsertBlock(); 1859 CGF.EmitBranch(ContBlock); 1860 1861 CGF.StartConditionalBranch(); 1862 CGF.EmitBlock(RHSBlock); 1863 1864 Value *RHS = Visit(E->getRHS()); 1865 CGF.FinishConditionalBranch(); 1866 RHSBlock = Builder.GetInsertBlock(); 1867 CGF.EmitBranch(ContBlock); 1868 1869 CGF.EmitBlock(ContBlock); 1870 1871 if (!LHS || !RHS) { 1872 assert(E->getType()->isVoidType() && "Non-void value should have a value"); 1873 return 0; 1874 } 1875 1876 // Create a PHI node for the real part. 1877 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 1878 PN->reserveOperandSpace(2); 1879 PN->addIncoming(LHS, LHSBlock); 1880 PN->addIncoming(RHS, RHSBlock); 1881 return PN; 1882} 1883 1884Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 1885 return Visit(E->getChosenSubExpr(CGF.getContext())); 1886} 1887 1888Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 1889 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 1890 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 1891 1892 // If EmitVAArg fails, we fall back to the LLVM instruction. 1893 if (!ArgPtr) 1894 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 1895 1896 // FIXME Volatility. 1897 return Builder.CreateLoad(ArgPtr); 1898} 1899 1900Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { 1901 return CGF.BuildBlockLiteralTmp(BE); 1902} 1903 1904//===----------------------------------------------------------------------===// 1905// Entry Point into this File 1906//===----------------------------------------------------------------------===// 1907 1908/// EmitScalarExpr - Emit the computation of the specified expression of scalar 1909/// type, ignoring the result. 1910Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 1911 assert(E && !hasAggregateLLVMType(E->getType()) && 1912 "Invalid scalar expression to emit"); 1913 1914 return ScalarExprEmitter(*this, IgnoreResultAssign) 1915 .Visit(const_cast<Expr*>(E)); 1916} 1917 1918/// EmitScalarConversion - Emit a conversion from the specified type to the 1919/// specified destination type, both of which are LLVM scalar types. 1920Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 1921 QualType DstTy) { 1922 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 1923 "Invalid scalar expression to emit"); 1924 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 1925} 1926 1927/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 1928/// type to the specified destination type, where the destination type is an 1929/// LLVM scalar type. 1930Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 1931 QualType SrcTy, 1932 QualType DstTy) { 1933 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 1934 "Invalid complex -> scalar conversion"); 1935 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 1936 DstTy); 1937} 1938 1939Value *CodeGenFunction::EmitShuffleVector(Value* V1, Value *V2, ...) { 1940 assert(V1->getType() == V2->getType() && 1941 "Vector operands must be of the same type"); 1942 unsigned NumElements = 1943 cast<llvm::VectorType>(V1->getType())->getNumElements(); 1944 1945 va_list va; 1946 va_start(va, V2); 1947 1948 llvm::SmallVector<llvm::Constant*, 16> Args; 1949 for (unsigned i = 0; i < NumElements; i++) { 1950 int n = va_arg(va, int); 1951 assert(n >= 0 && n < (int)NumElements * 2 && 1952 "Vector shuffle index out of bounds!"); 1953 Args.push_back(llvm::ConstantInt::get( 1954 llvm::Type::getInt32Ty(VMContext), n)); 1955 } 1956 1957 const char *Name = va_arg(va, const char *); 1958 va_end(va); 1959 1960 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 1961 1962 return Builder.CreateShuffleVector(V1, V2, Mask, Name); 1963} 1964 1965llvm::Value *CodeGenFunction::EmitVector(llvm::Value * const *Vals, 1966 unsigned NumVals, bool isSplat) { 1967 llvm::Value *Vec 1968 = llvm::UndefValue::get(llvm::VectorType::get(Vals[0]->getType(), NumVals)); 1969 1970 for (unsigned i = 0, e = NumVals; i != e; ++i) { 1971 llvm::Value *Val = isSplat ? Vals[0] : Vals[i]; 1972 llvm::Value *Idx = llvm::ConstantInt::get( 1973 llvm::Type::getInt32Ty(VMContext), i); 1974 Vec = Builder.CreateInsertElement(Vec, Val, Idx, "tmp"); 1975 } 1976 1977 return Vec; 1978} 1979