CGExprScalar.cpp revision 4c40d98ab7acf5f27fa89b17bd8fc0ef7683df37
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 "CGCXXABI.h" 16#include "CGObjCRuntime.h" 17#include "CodeGenModule.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/DeclObjC.h" 20#include "clang/AST/RecordLayout.h" 21#include "clang/AST/StmtVisitor.h" 22#include "clang/Basic/TargetInfo.h" 23#include "llvm/Constants.h" 24#include "llvm/Function.h" 25#include "llvm/GlobalVariable.h" 26#include "llvm/Intrinsics.h" 27#include "llvm/Module.h" 28#include "llvm/Support/CFG.h" 29#include "llvm/Target/TargetData.h" 30#include <cstdarg> 31 32using namespace clang; 33using namespace CodeGen; 34using llvm::Value; 35 36//===----------------------------------------------------------------------===// 37// Scalar Expression Emitter 38//===----------------------------------------------------------------------===// 39 40struct BinOpInfo { 41 Value *LHS; 42 Value *RHS; 43 QualType Ty; // Computation Type. 44 BinaryOperator::Opcode Opcode; // Opcode of BinOp to perform 45 const Expr *E; // Entire expr, for error unsupported. May not be binop. 46}; 47 48namespace { 49class ScalarExprEmitter 50 : public StmtVisitor<ScalarExprEmitter, Value*> { 51 CodeGenFunction &CGF; 52 CGBuilderTy &Builder; 53 bool IgnoreResultAssign; 54 llvm::LLVMContext &VMContext; 55public: 56 57 ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false) 58 : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira), 59 VMContext(cgf.getLLVMContext()) { 60 } 61 62 //===--------------------------------------------------------------------===// 63 // Utilities 64 //===--------------------------------------------------------------------===// 65 66 bool TestAndClearIgnoreResultAssign() { 67 bool I = IgnoreResultAssign; 68 IgnoreResultAssign = false; 69 return I; 70 } 71 72 const llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); } 73 LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); } 74 LValue EmitCheckedLValue(const Expr *E) { return CGF.EmitCheckedLValue(E); } 75 76 Value *EmitLoadOfLValue(LValue LV, QualType T) { 77 return CGF.EmitLoadOfLValue(LV, T).getScalarVal(); 78 } 79 80 /// EmitLoadOfLValue - Given an expression with complex type that represents a 81 /// value l-value, this method emits the address of the l-value, then loads 82 /// and returns the result. 83 Value *EmitLoadOfLValue(const Expr *E) { 84 return EmitLoadOfLValue(EmitCheckedLValue(E), E->getType()); 85 } 86 87 /// EmitConversionToBool - Convert the specified expression value to a 88 /// boolean (i1) truth value. This is equivalent to "Val != 0". 89 Value *EmitConversionToBool(Value *Src, QualType DstTy); 90 91 /// EmitScalarConversion - Emit a conversion from the specified type to the 92 /// specified destination type, both of which are LLVM scalar types. 93 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); 94 95 /// EmitComplexToScalarConversion - Emit a conversion from the specified 96 /// complex type to the specified destination type, where the destination type 97 /// is an LLVM scalar type. 98 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 99 QualType SrcTy, QualType DstTy); 100 101 /// EmitNullValue - Emit a value that corresponds to null for the given type. 102 Value *EmitNullValue(QualType Ty); 103 104 //===--------------------------------------------------------------------===// 105 // Visitor Methods 106 //===--------------------------------------------------------------------===// 107 108 Value *VisitStmt(Stmt *S) { 109 S->dump(CGF.getContext().getSourceManager()); 110 assert(0 && "Stmt can't have complex result type!"); 111 return 0; 112 } 113 Value *VisitExpr(Expr *S); 114 115 Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); } 116 117 // Leaves. 118 Value *VisitIntegerLiteral(const IntegerLiteral *E) { 119 return llvm::ConstantInt::get(VMContext, E->getValue()); 120 } 121 Value *VisitFloatingLiteral(const FloatingLiteral *E) { 122 return llvm::ConstantFP::get(VMContext, E->getValue()); 123 } 124 Value *VisitCharacterLiteral(const CharacterLiteral *E) { 125 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 126 } 127 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 128 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 129 } 130 Value *VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) { 131 return EmitNullValue(E->getType()); 132 } 133 Value *VisitGNUNullExpr(const GNUNullExpr *E) { 134 return EmitNullValue(E->getType()); 135 } 136 Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { 137 return llvm::ConstantInt::get(ConvertType(E->getType()), 138 CGF.getContext().typesAreCompatible( 139 E->getArgType1(), E->getArgType2())); 140 } 141 Value *VisitOffsetOfExpr(OffsetOfExpr *E); 142 Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); 143 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 144 llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel()); 145 return Builder.CreateBitCast(V, ConvertType(E->getType())); 146 } 147 148 // l-values. 149 Value *VisitDeclRefExpr(DeclRefExpr *E) { 150 Expr::EvalResult Result; 151 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 152 assert(!Result.HasSideEffects && "Constant declref with side-effect?!"); 153 llvm::ConstantInt *CI 154 = llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 155 CGF.EmitDeclRefExprDbgValue(E, CI); 156 return CI; 157 } 158 return EmitLoadOfLValue(E); 159 } 160 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 161 return CGF.EmitObjCSelectorExpr(E); 162 } 163 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 164 return CGF.EmitObjCProtocolExpr(E); 165 } 166 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 167 return EmitLoadOfLValue(E); 168 } 169 Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { 170 return EmitLoadOfLValue(E); 171 } 172 Value *VisitObjCImplicitSetterGetterRefExpr( 173 ObjCImplicitSetterGetterRefExpr *E) { 174 return EmitLoadOfLValue(E); 175 } 176 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 177 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 178 } 179 180 Value *VisitObjCIsaExpr(ObjCIsaExpr *E) { 181 LValue LV = CGF.EmitObjCIsaExpr(E); 182 Value *V = CGF.EmitLoadOfLValue(LV, E->getType()).getScalarVal(); 183 return V; 184 } 185 186 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 187 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 188 Value *VisitMemberExpr(MemberExpr *E); 189 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 190 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 191 return EmitLoadOfLValue(E); 192 } 193 194 Value *VisitInitListExpr(InitListExpr *E); 195 196 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { 197 return CGF.CGM.EmitNullConstant(E->getType()); 198 } 199 Value *VisitCastExpr(CastExpr *E) { 200 // Make sure to evaluate VLA bounds now so that we have them for later. 201 if (E->getType()->isVariablyModifiedType()) 202 CGF.EmitVLASize(E->getType()); 203 204 return EmitCastExpr(E); 205 } 206 Value *EmitCastExpr(CastExpr *E); 207 208 Value *VisitCallExpr(const CallExpr *E) { 209 if (E->getCallReturnType()->isReferenceType()) 210 return EmitLoadOfLValue(E); 211 212 return CGF.EmitCallExpr(E).getScalarVal(); 213 } 214 215 Value *VisitStmtExpr(const StmtExpr *E); 216 217 Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E); 218 219 // Unary Operators. 220 Value *VisitUnaryPostDec(const UnaryOperator *E) { 221 LValue LV = EmitLValue(E->getSubExpr()); 222 return EmitScalarPrePostIncDec(E, LV, false, false); 223 } 224 Value *VisitUnaryPostInc(const UnaryOperator *E) { 225 LValue LV = EmitLValue(E->getSubExpr()); 226 return EmitScalarPrePostIncDec(E, LV, true, false); 227 } 228 Value *VisitUnaryPreDec(const UnaryOperator *E) { 229 LValue LV = EmitLValue(E->getSubExpr()); 230 return EmitScalarPrePostIncDec(E, LV, false, true); 231 } 232 Value *VisitUnaryPreInc(const UnaryOperator *E) { 233 LValue LV = EmitLValue(E->getSubExpr()); 234 return EmitScalarPrePostIncDec(E, LV, true, true); 235 } 236 237 llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 238 bool isInc, bool isPre); 239 240 241 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 242 // If the sub-expression is an instance member reference, 243 // EmitDeclRefLValue will magically emit it with the appropriate 244 // value as the "address". 245 return EmitLValue(E->getSubExpr()).getAddress(); 246 } 247 Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } 248 Value *VisitUnaryPlus(const UnaryOperator *E) { 249 // This differs from gcc, though, most likely due to a bug in gcc. 250 TestAndClearIgnoreResultAssign(); 251 return Visit(E->getSubExpr()); 252 } 253 Value *VisitUnaryMinus (const UnaryOperator *E); 254 Value *VisitUnaryNot (const UnaryOperator *E); 255 Value *VisitUnaryLNot (const UnaryOperator *E); 256 Value *VisitUnaryReal (const UnaryOperator *E); 257 Value *VisitUnaryImag (const UnaryOperator *E); 258 Value *VisitUnaryExtension(const UnaryOperator *E) { 259 return Visit(E->getSubExpr()); 260 } 261 262 // C++ 263 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 264 return Visit(DAE->getExpr()); 265 } 266 Value *VisitCXXThisExpr(CXXThisExpr *TE) { 267 return CGF.LoadCXXThis(); 268 } 269 270 Value *VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) { 271 return CGF.EmitCXXExprWithTemporaries(E).getScalarVal(); 272 } 273 Value *VisitCXXNewExpr(const CXXNewExpr *E) { 274 return CGF.EmitCXXNewExpr(E); 275 } 276 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { 277 CGF.EmitCXXDeleteExpr(E); 278 return 0; 279 } 280 Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) { 281 return llvm::ConstantInt::get(Builder.getInt1Ty(), 282 E->EvaluateTrait(CGF.getContext())); 283 } 284 285 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { 286 // C++ [expr.pseudo]p1: 287 // The result shall only be used as the operand for the function call 288 // operator (), and the result of such a call has type void. The only 289 // effect is the evaluation of the postfix-expression before the dot or 290 // arrow. 291 CGF.EmitScalarExpr(E->getBase()); 292 return 0; 293 } 294 295 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { 296 return EmitNullValue(E->getType()); 297 } 298 299 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { 300 CGF.EmitCXXThrowExpr(E); 301 return 0; 302 } 303 304 // Binary Operators. 305 Value *EmitMul(const BinOpInfo &Ops) { 306 if (Ops.Ty->hasSignedIntegerRepresentation()) { 307 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 308 case LangOptions::SOB_Undefined: 309 return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul"); 310 case LangOptions::SOB_Defined: 311 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 312 case LangOptions::SOB_Trapping: 313 return EmitOverflowCheckedBinOp(Ops); 314 } 315 } 316 317 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 318 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 319 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 320 } 321 /// Create a binary op that checks for overflow. 322 /// Currently only supports +, - and *. 323 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 324 Value *EmitDiv(const BinOpInfo &Ops); 325 Value *EmitRem(const BinOpInfo &Ops); 326 Value *EmitAdd(const BinOpInfo &Ops); 327 Value *EmitSub(const BinOpInfo &Ops); 328 Value *EmitShl(const BinOpInfo &Ops); 329 Value *EmitShr(const BinOpInfo &Ops); 330 Value *EmitAnd(const BinOpInfo &Ops) { 331 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 332 } 333 Value *EmitXor(const BinOpInfo &Ops) { 334 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 335 } 336 Value *EmitOr (const BinOpInfo &Ops) { 337 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 338 } 339 340 BinOpInfo EmitBinOps(const BinaryOperator *E); 341 LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E, 342 Value *(ScalarExprEmitter::*F)(const BinOpInfo &), 343 Value *&Result); 344 345 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 346 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 347 348 // Binary operators and binary compound assignment operators. 349#define HANDLEBINOP(OP) \ 350 Value *VisitBin ## OP(const BinaryOperator *E) { \ 351 return Emit ## OP(EmitBinOps(E)); \ 352 } \ 353 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 354 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 355 } 356 HANDLEBINOP(Mul) 357 HANDLEBINOP(Div) 358 HANDLEBINOP(Rem) 359 HANDLEBINOP(Add) 360 HANDLEBINOP(Sub) 361 HANDLEBINOP(Shl) 362 HANDLEBINOP(Shr) 363 HANDLEBINOP(And) 364 HANDLEBINOP(Xor) 365 HANDLEBINOP(Or) 366#undef HANDLEBINOP 367 368 // Comparisons. 369 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 370 unsigned SICmpOpc, unsigned FCmpOpc); 371#define VISITCOMP(CODE, UI, SI, FP) \ 372 Value *VisitBin##CODE(const BinaryOperator *E) { \ 373 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 374 llvm::FCmpInst::FP); } 375 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT) 376 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT) 377 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE) 378 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE) 379 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ) 380 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE) 381#undef VISITCOMP 382 383 Value *VisitBinAssign (const BinaryOperator *E); 384 385 Value *VisitBinLAnd (const BinaryOperator *E); 386 Value *VisitBinLOr (const BinaryOperator *E); 387 Value *VisitBinComma (const BinaryOperator *E); 388 389 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } 390 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); } 391 392 // Other Operators. 393 Value *VisitBlockExpr(const BlockExpr *BE); 394 Value *VisitConditionalOperator(const ConditionalOperator *CO); 395 Value *VisitChooseExpr(ChooseExpr *CE); 396 Value *VisitVAArgExpr(VAArgExpr *VE); 397 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 398 return CGF.EmitObjCStringLiteral(E); 399 } 400}; 401} // end anonymous namespace. 402 403//===----------------------------------------------------------------------===// 404// Utilities 405//===----------------------------------------------------------------------===// 406 407/// EmitConversionToBool - Convert the specified expression value to a 408/// boolean (i1) truth value. This is equivalent to "Val != 0". 409Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 410 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs"); 411 412 if (SrcType->isRealFloatingType()) { 413 // Compare against 0.0 for fp scalars. 414 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 415 return Builder.CreateFCmpUNE(Src, Zero, "tobool"); 416 } 417 418 if (const MemberPointerType *MPT = dyn_cast<MemberPointerType>(SrcType)) 419 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, Src, MPT); 420 421 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 422 "Unknown scalar type to convert"); 423 424 // Because of the type rules of C, we often end up computing a logical value, 425 // then zero extending it to int, then wanting it as a logical value again. 426 // Optimize this common case. 427 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) { 428 if (ZI->getOperand(0)->getType() == 429 llvm::Type::getInt1Ty(CGF.getLLVMContext())) { 430 Value *Result = ZI->getOperand(0); 431 // If there aren't any more uses, zap the instruction to save space. 432 // Note that there can be more uses, for example if this 433 // is the result of an assignment. 434 if (ZI->use_empty()) 435 ZI->eraseFromParent(); 436 return Result; 437 } 438 } 439 440 // Compare against an integer or pointer null. 441 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 442 return Builder.CreateICmpNE(Src, Zero, "tobool"); 443} 444 445/// EmitScalarConversion - Emit a conversion from the specified type to the 446/// specified destination type, both of which are LLVM scalar types. 447Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 448 QualType DstType) { 449 SrcType = CGF.getContext().getCanonicalType(SrcType); 450 DstType = CGF.getContext().getCanonicalType(DstType); 451 if (SrcType == DstType) return Src; 452 453 if (DstType->isVoidType()) return 0; 454 455 // Handle conversions to bool first, they are special: comparisons against 0. 456 if (DstType->isBooleanType()) 457 return EmitConversionToBool(Src, SrcType); 458 459 const llvm::Type *DstTy = ConvertType(DstType); 460 461 // Ignore conversions like int -> uint. 462 if (Src->getType() == DstTy) 463 return Src; 464 465 // Handle pointer conversions next: pointers can only be converted to/from 466 // other pointers and integers. Check for pointer types in terms of LLVM, as 467 // some native types (like Obj-C id) may map to a pointer type. 468 if (isa<llvm::PointerType>(DstTy)) { 469 // The source value may be an integer, or a pointer. 470 if (isa<llvm::PointerType>(Src->getType())) 471 return Builder.CreateBitCast(Src, DstTy, "conv"); 472 473 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 474 // First, convert to the correct width so that we control the kind of 475 // extension. 476 const llvm::Type *MiddleTy = CGF.IntPtrTy; 477 bool InputSigned = SrcType->isSignedIntegerType(); 478 llvm::Value* IntResult = 479 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 480 // Then, cast to pointer. 481 return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); 482 } 483 484 if (isa<llvm::PointerType>(Src->getType())) { 485 // Must be an ptr to int cast. 486 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 487 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 488 } 489 490 // A scalar can be splatted to an extended vector of the same element type 491 if (DstType->isExtVectorType() && !SrcType->isVectorType()) { 492 // Cast the scalar to element type 493 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType(); 494 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 495 496 // Insert the element in element zero of an undef vector 497 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 498 llvm::Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, 0); 499 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 500 501 // Splat the element across to all elements 502 llvm::SmallVector<llvm::Constant*, 16> Args; 503 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 504 for (unsigned i = 0; i < NumElements; i++) 505 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 0)); 506 507 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 508 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 509 return Yay; 510 } 511 512 // Allow bitcast from vector to integer/fp of the same size. 513 if (isa<llvm::VectorType>(Src->getType()) || 514 isa<llvm::VectorType>(DstTy)) 515 return Builder.CreateBitCast(Src, DstTy, "conv"); 516 517 // Finally, we have the arithmetic types: real int/float. 518 if (isa<llvm::IntegerType>(Src->getType())) { 519 bool InputSigned = SrcType->isSignedIntegerType(); 520 if (isa<llvm::IntegerType>(DstTy)) 521 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 522 else if (InputSigned) 523 return Builder.CreateSIToFP(Src, DstTy, "conv"); 524 else 525 return Builder.CreateUIToFP(Src, DstTy, "conv"); 526 } 527 528 assert(Src->getType()->isFloatingPointTy() && "Unknown real conversion"); 529 if (isa<llvm::IntegerType>(DstTy)) { 530 if (DstType->isSignedIntegerType()) 531 return Builder.CreateFPToSI(Src, DstTy, "conv"); 532 else 533 return Builder.CreateFPToUI(Src, DstTy, "conv"); 534 } 535 536 assert(DstTy->isFloatingPointTy() && "Unknown real conversion"); 537 if (DstTy->getTypeID() < Src->getType()->getTypeID()) 538 return Builder.CreateFPTrunc(Src, DstTy, "conv"); 539 else 540 return Builder.CreateFPExt(Src, DstTy, "conv"); 541} 542 543/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 544/// type to the specified destination type, where the destination type is an 545/// LLVM scalar type. 546Value *ScalarExprEmitter:: 547EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 548 QualType SrcTy, QualType DstTy) { 549 // Get the source element type. 550 SrcTy = SrcTy->getAs<ComplexType>()->getElementType(); 551 552 // Handle conversions to bool first, they are special: comparisons against 0. 553 if (DstTy->isBooleanType()) { 554 // Complex != 0 -> (Real != 0) | (Imag != 0) 555 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 556 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 557 return Builder.CreateOr(Src.first, Src.second, "tobool"); 558 } 559 560 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 561 // the imaginary part of the complex value is discarded and the value of the 562 // real part is converted according to the conversion rules for the 563 // corresponding real type. 564 return EmitScalarConversion(Src.first, SrcTy, DstTy); 565} 566 567Value *ScalarExprEmitter::EmitNullValue(QualType Ty) { 568 if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>()) 569 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 570 571 return llvm::Constant::getNullValue(ConvertType(Ty)); 572} 573 574//===----------------------------------------------------------------------===// 575// Visitor Methods 576//===----------------------------------------------------------------------===// 577 578Value *ScalarExprEmitter::VisitExpr(Expr *E) { 579 CGF.ErrorUnsupported(E, "scalar expression"); 580 if (E->getType()->isVoidType()) 581 return 0; 582 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 583} 584 585Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 586 // Vector Mask Case 587 if (E->getNumSubExprs() == 2 || 588 (E->getNumSubExprs() == 3 && E->getExpr(2)->getType()->isVectorType())) { 589 Value *LHS = CGF.EmitScalarExpr(E->getExpr(0)); 590 Value *RHS = CGF.EmitScalarExpr(E->getExpr(1)); 591 Value *Mask; 592 593 const llvm::VectorType *LTy = cast<llvm::VectorType>(LHS->getType()); 594 unsigned LHSElts = LTy->getNumElements(); 595 596 if (E->getNumSubExprs() == 3) { 597 Mask = CGF.EmitScalarExpr(E->getExpr(2)); 598 599 // Shuffle LHS & RHS into one input vector. 600 llvm::SmallVector<llvm::Constant*, 32> concat; 601 for (unsigned i = 0; i != LHSElts; ++i) { 602 concat.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 2*i)); 603 concat.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 2*i+1)); 604 } 605 606 Value* CV = llvm::ConstantVector::get(concat.begin(), concat.size()); 607 LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat"); 608 LHSElts *= 2; 609 } else { 610 Mask = RHS; 611 } 612 613 const llvm::VectorType *MTy = cast<llvm::VectorType>(Mask->getType()); 614 llvm::Constant* EltMask; 615 616 // Treat vec3 like vec4. 617 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) 618 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 619 (1 << llvm::Log2_32(LHSElts+2))-1); 620 else if ((LHSElts == 3) && (E->getNumSubExprs() == 2)) 621 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 622 (1 << llvm::Log2_32(LHSElts+1))-1); 623 else 624 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 625 (1 << llvm::Log2_32(LHSElts))-1); 626 627 // Mask off the high bits of each shuffle index. 628 llvm::SmallVector<llvm::Constant *, 32> MaskV; 629 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) 630 MaskV.push_back(EltMask); 631 632 Value* MaskBits = llvm::ConstantVector::get(MaskV.begin(), MaskV.size()); 633 Mask = Builder.CreateAnd(Mask, MaskBits, "mask"); 634 635 // newv = undef 636 // mask = mask & maskbits 637 // for each elt 638 // n = extract mask i 639 // x = extract val n 640 // newv = insert newv, x, i 641 const llvm::VectorType *RTy = llvm::VectorType::get(LTy->getElementType(), 642 MTy->getNumElements()); 643 Value* NewV = llvm::UndefValue::get(RTy); 644 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) { 645 Value *Indx = llvm::ConstantInt::get(CGF.Int32Ty, i); 646 Indx = Builder.CreateExtractElement(Mask, Indx, "shuf_idx"); 647 Indx = Builder.CreateZExt(Indx, CGF.Int32Ty, "idx_zext"); 648 649 // Handle vec3 special since the index will be off by one for the RHS. 650 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) { 651 Value *cmpIndx, *newIndx; 652 cmpIndx = Builder.CreateICmpUGT(Indx, 653 llvm::ConstantInt::get(CGF.Int32Ty, 3), 654 "cmp_shuf_idx"); 655 newIndx = Builder.CreateSub(Indx, llvm::ConstantInt::get(CGF.Int32Ty,1), 656 "shuf_idx_adj"); 657 Indx = Builder.CreateSelect(cmpIndx, newIndx, Indx, "sel_shuf_idx"); 658 } 659 Value *VExt = Builder.CreateExtractElement(LHS, Indx, "shuf_elt"); 660 NewV = Builder.CreateInsertElement(NewV, VExt, Indx, "shuf_ins"); 661 } 662 return NewV; 663 } 664 665 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 666 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 667 668 // Handle vec3 special since the index will be off by one for the RHS. 669 llvm::SmallVector<llvm::Constant*, 32> indices; 670 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 671 llvm::Constant *C = cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i))); 672 const llvm::VectorType *VTy = cast<llvm::VectorType>(V1->getType()); 673 if (VTy->getNumElements() == 3) { 674 if (llvm::ConstantInt *CI = dyn_cast<llvm::ConstantInt>(C)) { 675 uint64_t cVal = CI->getZExtValue(); 676 if (cVal > 3) { 677 C = llvm::ConstantInt::get(C->getType(), cVal-1); 678 } 679 } 680 } 681 indices.push_back(C); 682 } 683 684 Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); 685 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 686} 687Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { 688 Expr::EvalResult Result; 689 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 690 if (E->isArrow()) 691 CGF.EmitScalarExpr(E->getBase()); 692 else 693 EmitLValue(E->getBase()); 694 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 695 } 696 return EmitLoadOfLValue(E); 697} 698 699Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 700 TestAndClearIgnoreResultAssign(); 701 702 // Emit subscript expressions in rvalue context's. For most cases, this just 703 // loads the lvalue formed by the subscript expr. However, we have to be 704 // careful, because the base of a vector subscript is occasionally an rvalue, 705 // so we can't get it as an lvalue. 706 if (!E->getBase()->getType()->isVectorType()) 707 return EmitLoadOfLValue(E); 708 709 // Handle the vector case. The base must be a vector, the index must be an 710 // integer value. 711 Value *Base = Visit(E->getBase()); 712 Value *Idx = Visit(E->getIdx()); 713 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerType(); 714 Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vecidxcast"); 715 return Builder.CreateExtractElement(Base, Idx, "vecext"); 716} 717 718static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, 719 unsigned Off, const llvm::Type *I32Ty) { 720 int MV = SVI->getMaskValue(Idx); 721 if (MV == -1) 722 return llvm::UndefValue::get(I32Ty); 723 return llvm::ConstantInt::get(I32Ty, Off+MV); 724} 725 726Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) { 727 bool Ignore = TestAndClearIgnoreResultAssign(); 728 (void)Ignore; 729 assert (Ignore == false && "init list ignored"); 730 unsigned NumInitElements = E->getNumInits(); 731 732 if (E->hadArrayRangeDesignator()) 733 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 734 735 const llvm::VectorType *VType = 736 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 737 738 // We have a scalar in braces. Just use the first element. 739 if (!VType) 740 return Visit(E->getInit(0)); 741 742 unsigned ResElts = VType->getNumElements(); 743 744 // Loop over initializers collecting the Value for each, and remembering 745 // whether the source was swizzle (ExtVectorElementExpr). This will allow 746 // us to fold the shuffle for the swizzle into the shuffle for the vector 747 // initializer, since LLVM optimizers generally do not want to touch 748 // shuffles. 749 unsigned CurIdx = 0; 750 bool VIsUndefShuffle = false; 751 llvm::Value *V = llvm::UndefValue::get(VType); 752 for (unsigned i = 0; i != NumInitElements; ++i) { 753 Expr *IE = E->getInit(i); 754 Value *Init = Visit(IE); 755 llvm::SmallVector<llvm::Constant*, 16> Args; 756 757 const llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType()); 758 759 // Handle scalar elements. If the scalar initializer is actually one 760 // element of a different vector of the same width, use shuffle instead of 761 // extract+insert. 762 if (!VVT) { 763 if (isa<ExtVectorElementExpr>(IE)) { 764 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init); 765 766 if (EI->getVectorOperandType()->getNumElements() == ResElts) { 767 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand()); 768 Value *LHS = 0, *RHS = 0; 769 if (CurIdx == 0) { 770 // insert into undef -> shuffle (src, undef) 771 Args.push_back(C); 772 for (unsigned j = 1; j != ResElts; ++j) 773 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 774 775 LHS = EI->getVectorOperand(); 776 RHS = V; 777 VIsUndefShuffle = true; 778 } else if (VIsUndefShuffle) { 779 // insert into undefshuffle && size match -> shuffle (v, src) 780 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V); 781 for (unsigned j = 0; j != CurIdx; ++j) 782 Args.push_back(getMaskElt(SVV, j, 0, CGF.Int32Ty)); 783 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 784 ResElts + C->getZExtValue())); 785 for (unsigned j = CurIdx + 1; j != ResElts; ++j) 786 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 787 788 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 789 RHS = EI->getVectorOperand(); 790 VIsUndefShuffle = false; 791 } 792 if (!Args.empty()) { 793 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 794 V = Builder.CreateShuffleVector(LHS, RHS, Mask); 795 ++CurIdx; 796 continue; 797 } 798 } 799 } 800 Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, CurIdx); 801 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 802 VIsUndefShuffle = false; 803 ++CurIdx; 804 continue; 805 } 806 807 unsigned InitElts = VVT->getNumElements(); 808 809 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's 810 // input is the same width as the vector being constructed, generate an 811 // optimized shuffle of the swizzle input into the result. 812 unsigned Offset = (CurIdx == 0) ? 0 : ResElts; 813 if (isa<ExtVectorElementExpr>(IE)) { 814 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init); 815 Value *SVOp = SVI->getOperand(0); 816 const llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType()); 817 818 if (OpTy->getNumElements() == ResElts) { 819 for (unsigned j = 0; j != CurIdx; ++j) { 820 // If the current vector initializer is a shuffle with undef, merge 821 // this shuffle directly into it. 822 if (VIsUndefShuffle) { 823 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0, 824 CGF.Int32Ty)); 825 } else { 826 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); 827 } 828 } 829 for (unsigned j = 0, je = InitElts; j != je; ++j) 830 Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty)); 831 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 832 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 833 834 if (VIsUndefShuffle) 835 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 836 837 Init = SVOp; 838 } 839 } 840 841 // Extend init to result vector length, and then shuffle its contribution 842 // to the vector initializer into V. 843 if (Args.empty()) { 844 for (unsigned j = 0; j != InitElts; ++j) 845 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); 846 for (unsigned j = InitElts; j != ResElts; ++j) 847 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 848 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 849 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), 850 Mask, "vext"); 851 852 Args.clear(); 853 for (unsigned j = 0; j != CurIdx; ++j) 854 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); 855 for (unsigned j = 0; j != InitElts; ++j) 856 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j+Offset)); 857 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 858 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 859 } 860 861 // If V is undef, make sure it ends up on the RHS of the shuffle to aid 862 // merging subsequent shuffles into this one. 863 if (CurIdx == 0) 864 std::swap(V, Init); 865 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 866 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); 867 VIsUndefShuffle = isa<llvm::UndefValue>(Init); 868 CurIdx += InitElts; 869 } 870 871 // FIXME: evaluate codegen vs. shuffling against constant null vector. 872 // Emit remaining default initializers. 873 const llvm::Type *EltTy = VType->getElementType(); 874 875 // Emit remaining default initializers 876 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { 877 Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, CurIdx); 878 llvm::Value *Init = llvm::Constant::getNullValue(EltTy); 879 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 880 } 881 return V; 882} 883 884static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { 885 const Expr *E = CE->getSubExpr(); 886 887 if (CE->getCastKind() == CK_UncheckedDerivedToBase) 888 return false; 889 890 if (isa<CXXThisExpr>(E)) { 891 // We always assume that 'this' is never null. 892 return false; 893 } 894 895 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { 896 // And that glvalue casts are never null. 897 if (ICE->getValueKind() != VK_RValue) 898 return false; 899 } 900 901 return true; 902} 903 904// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 905// have to handle a more broad range of conversions than explicit casts, as they 906// handle things like function to ptr-to-function decay etc. 907Value *ScalarExprEmitter::EmitCastExpr(CastExpr *CE) { 908 Expr *E = CE->getSubExpr(); 909 QualType DestTy = CE->getType(); 910 CastKind Kind = CE->getCastKind(); 911 912 if (!DestTy->isVoidType()) 913 TestAndClearIgnoreResultAssign(); 914 915 // Since almost all cast kinds apply to scalars, this switch doesn't have 916 // a default case, so the compiler will warn on a missing case. The cases 917 // are in the same order as in the CastKind enum. 918 switch (Kind) { 919 case CK_Unknown: 920 // FIXME: All casts should have a known kind! 921 //assert(0 && "Unknown cast kind!"); 922 break; 923 924 case CK_LValueBitCast: 925 case CK_ObjCObjectLValueCast: { 926 Value *V = EmitLValue(E).getAddress(); 927 V = Builder.CreateBitCast(V, 928 ConvertType(CGF.getContext().getPointerType(DestTy))); 929 return EmitLoadOfLValue(CGF.MakeAddrLValue(V, DestTy), DestTy); 930 } 931 932 case CK_AnyPointerToObjCPointerCast: 933 case CK_AnyPointerToBlockPointerCast: 934 case CK_BitCast: { 935 Value *Src = Visit(const_cast<Expr*>(E)); 936 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 937 } 938 case CK_NoOp: 939 case CK_UserDefinedConversion: 940 return Visit(const_cast<Expr*>(E)); 941 942 case CK_BaseToDerived: { 943 const CXXRecordDecl *DerivedClassDecl = 944 DestTy->getCXXRecordDeclForPointerType(); 945 946 return CGF.GetAddressOfDerivedClass(Visit(E), DerivedClassDecl, 947 CE->path_begin(), CE->path_end(), 948 ShouldNullCheckClassCastValue(CE)); 949 } 950 case CK_UncheckedDerivedToBase: 951 case CK_DerivedToBase: { 952 const RecordType *DerivedClassTy = 953 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 954 CXXRecordDecl *DerivedClassDecl = 955 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 956 957 return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl, 958 CE->path_begin(), CE->path_end(), 959 ShouldNullCheckClassCastValue(CE)); 960 } 961 case CK_Dynamic: { 962 Value *V = Visit(const_cast<Expr*>(E)); 963 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 964 return CGF.EmitDynamicCast(V, DCE); 965 } 966 case CK_ToUnion: 967 assert(0 && "Should be unreachable!"); 968 break; 969 970 case CK_ArrayToPointerDecay: { 971 assert(E->getType()->isArrayType() && 972 "Array to pointer decay must have array source type!"); 973 974 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 975 976 // Note that VLA pointers are always decayed, so we don't need to do 977 // anything here. 978 if (!E->getType()->isVariableArrayType()) { 979 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 980 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 981 ->getElementType()) && 982 "Expected pointer to array"); 983 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 984 } 985 986 return V; 987 } 988 case CK_FunctionToPointerDecay: 989 return EmitLValue(E).getAddress(); 990 991 case CK_NullToMemberPointer: { 992 // If the subexpression's type is the C++0x nullptr_t, emit the 993 // subexpression, which may have side effects. 994 if (E->getType()->isNullPtrType()) 995 (void) Visit(E); 996 997 const MemberPointerType *MPT = CE->getType()->getAs<MemberPointerType>(); 998 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 999 } 1000 1001 case CK_BaseToDerivedMemberPointer: 1002 case CK_DerivedToBaseMemberPointer: { 1003 Value *Src = Visit(E); 1004 1005 // Note that the AST doesn't distinguish between checked and 1006 // unchecked member pointer conversions, so we always have to 1007 // implement checked conversions here. This is inefficient when 1008 // actual control flow may be required in order to perform the 1009 // check, which it is for data member pointers (but not member 1010 // function pointers on Itanium and ARM). 1011 return CGF.CGM.getCXXABI().EmitMemberPointerConversion(CGF, CE, Src); 1012 } 1013 1014 1015 case CK_ConstructorConversion: 1016 assert(0 && "Should be unreachable!"); 1017 break; 1018 1019 case CK_IntegralToPointer: { 1020 Value *Src = Visit(const_cast<Expr*>(E)); 1021 1022 // First, convert to the correct width so that we control the kind of 1023 // extension. 1024 const llvm::Type *MiddleTy = CGF.IntPtrTy; 1025 bool InputSigned = E->getType()->isSignedIntegerType(); 1026 llvm::Value* IntResult = 1027 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 1028 1029 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 1030 } 1031 case CK_PointerToIntegral: { 1032 Value *Src = Visit(const_cast<Expr*>(E)); 1033 1034 // Handle conversion to bool correctly. 1035 if (DestTy->isBooleanType()) 1036 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 1037 1038 return Builder.CreatePtrToInt(Src, ConvertType(DestTy)); 1039 } 1040 case CK_ToVoid: { 1041 if (E->Classify(CGF.getContext()).isGLValue()) 1042 CGF.EmitLValue(E); 1043 else 1044 CGF.EmitAnyExpr(E, 0, false, true); 1045 return 0; 1046 } 1047 case CK_VectorSplat: { 1048 const llvm::Type *DstTy = ConvertType(DestTy); 1049 Value *Elt = Visit(const_cast<Expr*>(E)); 1050 1051 // Insert the element in element zero of an undef vector 1052 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 1053 llvm::Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, 0); 1054 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 1055 1056 // Splat the element across to all elements 1057 llvm::SmallVector<llvm::Constant*, 16> Args; 1058 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 1059 for (unsigned i = 0; i < NumElements; i++) 1060 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 0)); 1061 1062 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 1063 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 1064 return Yay; 1065 } 1066 case CK_IntegralCast: 1067 case CK_IntegralToFloating: 1068 case CK_FloatingToIntegral: 1069 case CK_FloatingCast: 1070 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 1071 1072 case CK_MemberPointerToBoolean: { 1073 llvm::Value *MemPtr = Visit(E); 1074 const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>(); 1075 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT); 1076 } 1077 } 1078 1079 // Handle cases where the source is an non-complex type. 1080 1081 if (!CGF.hasAggregateLLVMType(E->getType())) { 1082 Value *Src = Visit(const_cast<Expr*>(E)); 1083 1084 // Use EmitScalarConversion to perform the conversion. 1085 return EmitScalarConversion(Src, E->getType(), DestTy); 1086 } 1087 1088 if (E->getType()->isAnyComplexType()) { 1089 // Handle cases where the source is a complex type. 1090 bool IgnoreImag = true; 1091 bool IgnoreImagAssign = true; 1092 bool IgnoreReal = IgnoreResultAssign; 1093 bool IgnoreRealAssign = IgnoreResultAssign; 1094 if (DestTy->isBooleanType()) 1095 IgnoreImagAssign = IgnoreImag = false; 1096 else if (DestTy->isVoidType()) { 1097 IgnoreReal = IgnoreImag = false; 1098 IgnoreRealAssign = IgnoreImagAssign = true; 1099 } 1100 CodeGenFunction::ComplexPairTy V 1101 = CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign, 1102 IgnoreImagAssign); 1103 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 1104 } 1105 1106 // Okay, this is a cast from an aggregate. It must be a cast to void. Just 1107 // evaluate the result and return. 1108 CGF.EmitAggExpr(E, 0, false, true); 1109 return 0; 1110} 1111 1112Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 1113 return CGF.EmitCompoundStmt(*E->getSubStmt(), 1114 !E->getType()->isVoidType()).getScalarVal(); 1115} 1116 1117Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 1118 llvm::Value *V = CGF.GetAddrOfBlockDecl(E); 1119 if (E->getType().isObjCGCWeak()) 1120 return CGF.CGM.getObjCRuntime().EmitObjCWeakRead(CGF, V); 1121 return Builder.CreateLoad(V, "tmp"); 1122} 1123 1124//===----------------------------------------------------------------------===// 1125// Unary Operators 1126//===----------------------------------------------------------------------===// 1127 1128llvm::Value *ScalarExprEmitter:: 1129EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 1130 bool isInc, bool isPre) { 1131 1132 QualType ValTy = E->getSubExpr()->getType(); 1133 llvm::Value *InVal = EmitLoadOfLValue(LV, ValTy); 1134 1135 int AmountVal = isInc ? 1 : -1; 1136 1137 if (ValTy->isPointerType() && 1138 ValTy->getAs<PointerType>()->isVariableArrayType()) { 1139 // The amount of the addition/subtraction needs to account for the VLA size 1140 CGF.ErrorUnsupported(E, "VLA pointer inc/dec"); 1141 } 1142 1143 llvm::Value *NextVal; 1144 if (const llvm::PointerType *PT = 1145 dyn_cast<llvm::PointerType>(InVal->getType())) { 1146 llvm::Constant *Inc = llvm::ConstantInt::get(CGF.Int32Ty, AmountVal); 1147 if (!isa<llvm::FunctionType>(PT->getElementType())) { 1148 QualType PTEE = ValTy->getPointeeType(); 1149 if (const ObjCObjectType *OIT = PTEE->getAs<ObjCObjectType>()) { 1150 // Handle interface types, which are not represented with a concrete 1151 // type. 1152 int size = CGF.getContext().getTypeSize(OIT) / 8; 1153 if (!isInc) 1154 size = -size; 1155 Inc = llvm::ConstantInt::get(Inc->getType(), size); 1156 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1157 InVal = Builder.CreateBitCast(InVal, i8Ty); 1158 NextVal = Builder.CreateGEP(InVal, Inc, "add.ptr"); 1159 llvm::Value *lhs = LV.getAddress(); 1160 lhs = Builder.CreateBitCast(lhs, llvm::PointerType::getUnqual(i8Ty)); 1161 LV = CGF.MakeAddrLValue(lhs, ValTy); 1162 } else 1163 NextVal = Builder.CreateInBoundsGEP(InVal, Inc, "ptrincdec"); 1164 } else { 1165 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1166 NextVal = Builder.CreateBitCast(InVal, i8Ty, "tmp"); 1167 NextVal = Builder.CreateGEP(NextVal, Inc, "ptrincdec"); 1168 NextVal = Builder.CreateBitCast(NextVal, InVal->getType()); 1169 } 1170 } else if (InVal->getType()->isIntegerTy(1) && isInc) { 1171 // Bool++ is an interesting case, due to promotion rules, we get: 1172 // Bool++ -> Bool = Bool+1 -> Bool = (int)Bool+1 -> 1173 // Bool = ((int)Bool+1) != 0 1174 // An interesting aspect of this is that increment is always true. 1175 // Decrement does not have this property. 1176 NextVal = llvm::ConstantInt::getTrue(VMContext); 1177 } else if (isa<llvm::IntegerType>(InVal->getType())) { 1178 NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); 1179 1180 if (!ValTy->isSignedIntegerType()) 1181 // Unsigned integer inc is always two's complement. 1182 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1183 else { 1184 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1185 case LangOptions::SOB_Undefined: 1186 NextVal = Builder.CreateNSWAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1187 break; 1188 case LangOptions::SOB_Defined: 1189 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1190 break; 1191 case LangOptions::SOB_Trapping: 1192 BinOpInfo BinOp; 1193 BinOp.LHS = InVal; 1194 BinOp.RHS = NextVal; 1195 BinOp.Ty = E->getType(); 1196 BinOp.Opcode = BO_Add; 1197 BinOp.E = E; 1198 NextVal = EmitOverflowCheckedBinOp(BinOp); 1199 break; 1200 } 1201 } 1202 } else { 1203 // Add the inc/dec to the real part. 1204 if (InVal->getType()->isFloatTy()) 1205 NextVal = 1206 llvm::ConstantFP::get(VMContext, 1207 llvm::APFloat(static_cast<float>(AmountVal))); 1208 else if (InVal->getType()->isDoubleTy()) 1209 NextVal = 1210 llvm::ConstantFP::get(VMContext, 1211 llvm::APFloat(static_cast<double>(AmountVal))); 1212 else { 1213 llvm::APFloat F(static_cast<float>(AmountVal)); 1214 bool ignored; 1215 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, 1216 &ignored); 1217 NextVal = llvm::ConstantFP::get(VMContext, F); 1218 } 1219 NextVal = Builder.CreateFAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1220 } 1221 1222 // Store the updated result through the lvalue. 1223 if (LV.isBitField()) 1224 CGF.EmitStoreThroughBitfieldLValue(RValue::get(NextVal), LV, ValTy, &NextVal); 1225 else 1226 CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV, ValTy); 1227 1228 // If this is a postinc, return the value read from memory, otherwise use the 1229 // updated value. 1230 return isPre ? NextVal : InVal; 1231} 1232 1233 1234 1235Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1236 TestAndClearIgnoreResultAssign(); 1237 // Emit unary minus with EmitSub so we handle overflow cases etc. 1238 BinOpInfo BinOp; 1239 BinOp.RHS = Visit(E->getSubExpr()); 1240 1241 if (BinOp.RHS->getType()->isFPOrFPVectorTy()) 1242 BinOp.LHS = llvm::ConstantFP::getZeroValueForNegation(BinOp.RHS->getType()); 1243 else 1244 BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType()); 1245 BinOp.Ty = E->getType(); 1246 BinOp.Opcode = BO_Sub; 1247 BinOp.E = E; 1248 return EmitSub(BinOp); 1249} 1250 1251Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1252 TestAndClearIgnoreResultAssign(); 1253 Value *Op = Visit(E->getSubExpr()); 1254 return Builder.CreateNot(Op, "neg"); 1255} 1256 1257Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1258 // Compare operand to zero. 1259 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1260 1261 // Invert value. 1262 // TODO: Could dynamically modify easy computations here. For example, if 1263 // the operand is an icmp ne, turn into icmp eq. 1264 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1265 1266 // ZExt result to the expr type. 1267 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1268} 1269 1270Value *ScalarExprEmitter::VisitOffsetOfExpr(OffsetOfExpr *E) { 1271 // Try folding the offsetof to a constant. 1272 Expr::EvalResult EvalResult; 1273 if (E->Evaluate(EvalResult, CGF.getContext())) 1274 return llvm::ConstantInt::get(VMContext, EvalResult.Val.getInt()); 1275 1276 // Loop over the components of the offsetof to compute the value. 1277 unsigned n = E->getNumComponents(); 1278 const llvm::Type* ResultType = ConvertType(E->getType()); 1279 llvm::Value* Result = llvm::Constant::getNullValue(ResultType); 1280 QualType CurrentType = E->getTypeSourceInfo()->getType(); 1281 for (unsigned i = 0; i != n; ++i) { 1282 OffsetOfExpr::OffsetOfNode ON = E->getComponent(i); 1283 llvm::Value *Offset = 0; 1284 switch (ON.getKind()) { 1285 case OffsetOfExpr::OffsetOfNode::Array: { 1286 // Compute the index 1287 Expr *IdxExpr = E->getIndexExpr(ON.getArrayExprIndex()); 1288 llvm::Value* Idx = CGF.EmitScalarExpr(IdxExpr); 1289 bool IdxSigned = IdxExpr->getType()->isSignedIntegerType(); 1290 Idx = Builder.CreateIntCast(Idx, ResultType, IdxSigned, "conv"); 1291 1292 // Save the element type 1293 CurrentType = 1294 CGF.getContext().getAsArrayType(CurrentType)->getElementType(); 1295 1296 // Compute the element size 1297 llvm::Value* ElemSize = llvm::ConstantInt::get(ResultType, 1298 CGF.getContext().getTypeSizeInChars(CurrentType).getQuantity()); 1299 1300 // Multiply out to compute the result 1301 Offset = Builder.CreateMul(Idx, ElemSize); 1302 break; 1303 } 1304 1305 case OffsetOfExpr::OffsetOfNode::Field: { 1306 FieldDecl *MemberDecl = ON.getField(); 1307 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1308 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1309 1310 // Compute the index of the field in its parent. 1311 unsigned i = 0; 1312 // FIXME: It would be nice if we didn't have to loop here! 1313 for (RecordDecl::field_iterator Field = RD->field_begin(), 1314 FieldEnd = RD->field_end(); 1315 Field != FieldEnd; (void)++Field, ++i) { 1316 if (*Field == MemberDecl) 1317 break; 1318 } 1319 assert(i < RL.getFieldCount() && "offsetof field in wrong type"); 1320 1321 // Compute the offset to the field 1322 int64_t OffsetInt = RL.getFieldOffset(i) / 1323 CGF.getContext().getCharWidth(); 1324 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1325 1326 // Save the element type. 1327 CurrentType = MemberDecl->getType(); 1328 break; 1329 } 1330 1331 case OffsetOfExpr::OffsetOfNode::Identifier: 1332 llvm_unreachable("dependent __builtin_offsetof"); 1333 1334 case OffsetOfExpr::OffsetOfNode::Base: { 1335 if (ON.getBase()->isVirtual()) { 1336 CGF.ErrorUnsupported(E, "virtual base in offsetof"); 1337 continue; 1338 } 1339 1340 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1341 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1342 1343 // Save the element type. 1344 CurrentType = ON.getBase()->getType(); 1345 1346 // Compute the offset to the base. 1347 const RecordType *BaseRT = CurrentType->getAs<RecordType>(); 1348 CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl()); 1349 int64_t OffsetInt = RL.getBaseClassOffset(BaseRD) / 1350 CGF.getContext().getCharWidth(); 1351 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1352 break; 1353 } 1354 } 1355 Result = Builder.CreateAdd(Result, Offset); 1356 } 1357 return Result; 1358} 1359 1360/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of 1361/// argument of the sizeof expression as an integer. 1362Value * 1363ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { 1364 QualType TypeToSize = E->getTypeOfArgument(); 1365 if (E->isSizeOf()) { 1366 if (const VariableArrayType *VAT = 1367 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1368 if (E->isArgumentType()) { 1369 // sizeof(type) - make sure to emit the VLA size. 1370 CGF.EmitVLASize(TypeToSize); 1371 } else { 1372 // C99 6.5.3.4p2: If the argument is an expression of type 1373 // VLA, it is evaluated. 1374 CGF.EmitAnyExpr(E->getArgumentExpr()); 1375 } 1376 1377 return CGF.GetVLASize(VAT); 1378 } 1379 } 1380 1381 // If this isn't sizeof(vla), the result must be constant; use the constant 1382 // folding logic so we don't have to duplicate it here. 1383 Expr::EvalResult Result; 1384 E->Evaluate(Result, CGF.getContext()); 1385 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 1386} 1387 1388Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1389 Expr *Op = E->getSubExpr(); 1390 if (Op->getType()->isAnyComplexType()) 1391 return CGF.EmitComplexExpr(Op, false, true, false, true).first; 1392 return Visit(Op); 1393} 1394Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1395 Expr *Op = E->getSubExpr(); 1396 if (Op->getType()->isAnyComplexType()) 1397 return CGF.EmitComplexExpr(Op, true, false, true, false).second; 1398 1399 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1400 // effects are evaluated, but not the actual value. 1401 if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) 1402 CGF.EmitLValue(Op); 1403 else 1404 CGF.EmitScalarExpr(Op, true); 1405 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1406} 1407 1408//===----------------------------------------------------------------------===// 1409// Binary Operators 1410//===----------------------------------------------------------------------===// 1411 1412BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1413 TestAndClearIgnoreResultAssign(); 1414 BinOpInfo Result; 1415 Result.LHS = Visit(E->getLHS()); 1416 Result.RHS = Visit(E->getRHS()); 1417 Result.Ty = E->getType(); 1418 Result.Opcode = E->getOpcode(); 1419 Result.E = E; 1420 return Result; 1421} 1422 1423LValue ScalarExprEmitter::EmitCompoundAssignLValue( 1424 const CompoundAssignOperator *E, 1425 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &), 1426 Value *&Result) { 1427 QualType LHSTy = E->getLHS()->getType(); 1428 BinOpInfo OpInfo; 1429 1430 if (E->getComputationResultType()->isAnyComplexType()) { 1431 // This needs to go through the complex expression emitter, but it's a tad 1432 // complicated to do that... I'm leaving it out for now. (Note that we do 1433 // actually need the imaginary part of the RHS for multiplication and 1434 // division.) 1435 CGF.ErrorUnsupported(E, "complex compound assignment"); 1436 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType())); 1437 return LValue(); 1438 } 1439 1440 // Emit the RHS first. __block variables need to have the rhs evaluated 1441 // first, plus this should improve codegen a little. 1442 OpInfo.RHS = Visit(E->getRHS()); 1443 OpInfo.Ty = E->getComputationResultType(); 1444 OpInfo.Opcode = E->getOpcode(); 1445 OpInfo.E = E; 1446 // Load/convert the LHS. 1447 LValue LHSLV = EmitCheckedLValue(E->getLHS()); 1448 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 1449 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 1450 E->getComputationLHSType()); 1451 1452 // Expand the binary operator. 1453 Result = (this->*Func)(OpInfo); 1454 1455 // Convert the result back to the LHS type. 1456 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 1457 1458 // Store the result value into the LHS lvalue. Bit-fields are handled 1459 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 1460 // 'An assignment expression has the value of the left operand after the 1461 // assignment...'. 1462 if (LHSLV.isBitField()) 1463 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, 1464 &Result); 1465 else 1466 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); 1467 1468 return LHSLV; 1469} 1470 1471Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 1472 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 1473 bool Ignore = TestAndClearIgnoreResultAssign(); 1474 Value *RHS; 1475 LValue LHS = EmitCompoundAssignLValue(E, Func, RHS); 1476 1477 // If the result is clearly ignored, return now. 1478 if (Ignore) 1479 return 0; 1480 1481 // Objective-C property assignment never reloads the value following a store. 1482 if (LHS.isPropertyRef() || LHS.isKVCRef()) 1483 return RHS; 1484 1485 // If the lvalue is non-volatile, return the computed value of the assignment. 1486 if (!LHS.isVolatileQualified()) 1487 return RHS; 1488 1489 // Otherwise, reload the value. 1490 return EmitLoadOfLValue(LHS, E->getType()); 1491} 1492 1493 1494Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 1495 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1496 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 1497 else if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1498 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 1499 else 1500 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 1501} 1502 1503Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 1504 // Rem in C can't be a floating point type: C99 6.5.5p2. 1505 if (Ops.Ty->isUnsignedIntegerType()) 1506 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 1507 else 1508 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 1509} 1510 1511Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 1512 unsigned IID; 1513 unsigned OpID = 0; 1514 1515 switch (Ops.Opcode) { 1516 case BO_Add: 1517 case BO_AddAssign: 1518 OpID = 1; 1519 IID = llvm::Intrinsic::sadd_with_overflow; 1520 break; 1521 case BO_Sub: 1522 case BO_SubAssign: 1523 OpID = 2; 1524 IID = llvm::Intrinsic::ssub_with_overflow; 1525 break; 1526 case BO_Mul: 1527 case BO_MulAssign: 1528 OpID = 3; 1529 IID = llvm::Intrinsic::smul_with_overflow; 1530 break; 1531 default: 1532 assert(false && "Unsupported operation for overflow detection"); 1533 IID = 0; 1534 } 1535 OpID <<= 1; 1536 OpID |= 1; 1537 1538 const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1539 1540 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1); 1541 1542 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1543 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1544 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1545 1546 // Branch in case of overflow. 1547 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); 1548 llvm::BasicBlock *continueBB = CGF.createBasicBlock("nooverflow", CGF.CurFn); 1549 1550 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1551 1552 // Handle overflow with llvm.trap. 1553 // TODO: it would be better to generate one of these blocks per function. 1554 Builder.SetInsertPoint(overflowBB); 1555 llvm::Function *Trap = CGF.CGM.getIntrinsic(llvm::Intrinsic::trap); 1556 Builder.CreateCall(Trap); 1557 Builder.CreateUnreachable(); 1558 1559 // Continue on. 1560 Builder.SetInsertPoint(continueBB); 1561 return result; 1562} 1563 1564Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 1565 if (!Ops.Ty->isAnyPointerType()) { 1566 if (Ops.Ty->hasSignedIntegerRepresentation()) { 1567 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1568 case LangOptions::SOB_Undefined: 1569 return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add"); 1570 case LangOptions::SOB_Defined: 1571 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1572 case LangOptions::SOB_Trapping: 1573 return EmitOverflowCheckedBinOp(Ops); 1574 } 1575 } 1576 1577 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1578 return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add"); 1579 1580 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1581 } 1582 1583 // Must have binary (not unary) expr here. Unary pointer decrement doesn't 1584 // use this path. 1585 const BinaryOperator *BinOp = cast<BinaryOperator>(Ops.E); 1586 1587 if (Ops.Ty->isPointerType() && 1588 Ops.Ty->getAs<PointerType>()->isVariableArrayType()) { 1589 // The amount of the addition needs to account for the VLA size 1590 CGF.ErrorUnsupported(BinOp, "VLA pointer addition"); 1591 } 1592 1593 Value *Ptr, *Idx; 1594 Expr *IdxExp; 1595 const PointerType *PT = BinOp->getLHS()->getType()->getAs<PointerType>(); 1596 const ObjCObjectPointerType *OPT = 1597 BinOp->getLHS()->getType()->getAs<ObjCObjectPointerType>(); 1598 if (PT || OPT) { 1599 Ptr = Ops.LHS; 1600 Idx = Ops.RHS; 1601 IdxExp = BinOp->getRHS(); 1602 } else { // int + pointer 1603 PT = BinOp->getRHS()->getType()->getAs<PointerType>(); 1604 OPT = BinOp->getRHS()->getType()->getAs<ObjCObjectPointerType>(); 1605 assert((PT || OPT) && "Invalid add expr"); 1606 Ptr = Ops.RHS; 1607 Idx = Ops.LHS; 1608 IdxExp = BinOp->getLHS(); 1609 } 1610 1611 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1612 if (Width < CGF.LLVMPointerWidth) { 1613 // Zero or sign extend the pointer value based on whether the index is 1614 // signed or not. 1615 const llvm::Type *IdxType = CGF.IntPtrTy; 1616 if (IdxExp->getType()->isSignedIntegerType()) 1617 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1618 else 1619 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1620 } 1621 const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType(); 1622 // Handle interface types, which are not represented with a concrete type. 1623 if (const ObjCObjectType *OIT = ElementType->getAs<ObjCObjectType>()) { 1624 llvm::Value *InterfaceSize = 1625 llvm::ConstantInt::get(Idx->getType(), 1626 CGF.getContext().getTypeSizeInChars(OIT).getQuantity()); 1627 Idx = Builder.CreateMul(Idx, InterfaceSize); 1628 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1629 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1630 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1631 return Builder.CreateBitCast(Res, Ptr->getType()); 1632 } 1633 1634 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 1635 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 1636 // future proof. 1637 if (ElementType->isVoidType() || ElementType->isFunctionType()) { 1638 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1639 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1640 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1641 return Builder.CreateBitCast(Res, Ptr->getType()); 1642 } 1643 1644 return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr"); 1645} 1646 1647Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 1648 if (!isa<llvm::PointerType>(Ops.LHS->getType())) { 1649 if (Ops.Ty->hasSignedIntegerRepresentation()) { 1650 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1651 case LangOptions::SOB_Undefined: 1652 return Builder.CreateNSWSub(Ops.LHS, Ops.RHS, "sub"); 1653 case LangOptions::SOB_Defined: 1654 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1655 case LangOptions::SOB_Trapping: 1656 return EmitOverflowCheckedBinOp(Ops); 1657 } 1658 } 1659 1660 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1661 return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub"); 1662 1663 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1664 } 1665 1666 // Must have binary (not unary) expr here. Unary pointer increment doesn't 1667 // use this path. 1668 const BinaryOperator *BinOp = cast<BinaryOperator>(Ops.E); 1669 1670 if (BinOp->getLHS()->getType()->isPointerType() && 1671 BinOp->getLHS()->getType()->getAs<PointerType>()->isVariableArrayType()) { 1672 // The amount of the addition needs to account for the VLA size for 1673 // ptr-int 1674 // The amount of the division needs to account for the VLA size for 1675 // ptr-ptr. 1676 CGF.ErrorUnsupported(BinOp, "VLA pointer subtraction"); 1677 } 1678 1679 const QualType LHSType = BinOp->getLHS()->getType(); 1680 const QualType LHSElementType = LHSType->getPointeeType(); 1681 if (!isa<llvm::PointerType>(Ops.RHS->getType())) { 1682 // pointer - int 1683 Value *Idx = Ops.RHS; 1684 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1685 if (Width < CGF.LLVMPointerWidth) { 1686 // Zero or sign extend the pointer value based on whether the index is 1687 // signed or not. 1688 const llvm::Type *IdxType = CGF.IntPtrTy; 1689 if (BinOp->getRHS()->getType()->isSignedIntegerType()) 1690 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1691 else 1692 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1693 } 1694 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); 1695 1696 // Handle interface types, which are not represented with a concrete type. 1697 if (const ObjCObjectType *OIT = LHSElementType->getAs<ObjCObjectType>()) { 1698 llvm::Value *InterfaceSize = 1699 llvm::ConstantInt::get(Idx->getType(), 1700 CGF.getContext(). 1701 getTypeSizeInChars(OIT).getQuantity()); 1702 Idx = Builder.CreateMul(Idx, InterfaceSize); 1703 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1704 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1705 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr"); 1706 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1707 } 1708 1709 // Explicitly handle GNU void* and function pointer arithmetic 1710 // extensions. The GNU void* casts amount to no-ops since our void* type is 1711 // i8*, but this is future proof. 1712 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1713 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1714 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1715 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); 1716 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1717 } 1718 1719 return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr"); 1720 } else { 1721 // pointer - pointer 1722 Value *LHS = Ops.LHS; 1723 Value *RHS = Ops.RHS; 1724 1725 CharUnits ElementSize; 1726 1727 // Handle GCC extension for pointer arithmetic on void* and function pointer 1728 // types. 1729 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1730 ElementSize = CharUnits::One(); 1731 } else { 1732 ElementSize = CGF.getContext().getTypeSizeInChars(LHSElementType); 1733 } 1734 1735 const llvm::Type *ResultType = ConvertType(Ops.Ty); 1736 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 1737 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 1738 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 1739 1740 // Optimize out the shift for element size of 1. 1741 if (ElementSize.isOne()) 1742 return BytesBetween; 1743 1744 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 1745 // pointer difference in C is only defined in the case where both operands 1746 // are pointing to elements of an array. 1747 Value *BytesPerElt = 1748 llvm::ConstantInt::get(ResultType, ElementSize.getQuantity()); 1749 return Builder.CreateExactSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 1750 } 1751} 1752 1753Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 1754 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1755 // RHS to the same size as the LHS. 1756 Value *RHS = Ops.RHS; 1757 if (Ops.LHS->getType() != RHS->getType()) 1758 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1759 1760 if (CGF.CatchUndefined 1761 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1762 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1763 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1764 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1765 llvm::ConstantInt::get(RHS->getType(), Width)), 1766 Cont, CGF.getTrapBB()); 1767 CGF.EmitBlock(Cont); 1768 } 1769 1770 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 1771} 1772 1773Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 1774 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1775 // RHS to the same size as the LHS. 1776 Value *RHS = Ops.RHS; 1777 if (Ops.LHS->getType() != RHS->getType()) 1778 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1779 1780 if (CGF.CatchUndefined 1781 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1782 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1783 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1784 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1785 llvm::ConstantInt::get(RHS->getType(), Width)), 1786 Cont, CGF.getTrapBB()); 1787 CGF.EmitBlock(Cont); 1788 } 1789 1790 if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1791 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 1792 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 1793} 1794 1795Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 1796 unsigned SICmpOpc, unsigned FCmpOpc) { 1797 TestAndClearIgnoreResultAssign(); 1798 Value *Result; 1799 QualType LHSTy = E->getLHS()->getType(); 1800 if (const MemberPointerType *MPT = LHSTy->getAs<MemberPointerType>()) { 1801 assert(E->getOpcode() == BO_EQ || 1802 E->getOpcode() == BO_NE); 1803 Value *LHS = CGF.EmitScalarExpr(E->getLHS()); 1804 Value *RHS = CGF.EmitScalarExpr(E->getRHS()); 1805 Result = CGF.CGM.getCXXABI().EmitMemberPointerComparison( 1806 CGF, LHS, RHS, MPT, E->getOpcode() == BO_NE); 1807 } else if (!LHSTy->isAnyComplexType()) { 1808 Value *LHS = Visit(E->getLHS()); 1809 Value *RHS = Visit(E->getRHS()); 1810 1811 if (LHS->getType()->isFPOrFPVectorTy()) { 1812 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 1813 LHS, RHS, "cmp"); 1814 } else if (LHSTy->hasSignedIntegerRepresentation()) { 1815 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 1816 LHS, RHS, "cmp"); 1817 } else { 1818 // Unsigned integers and pointers. 1819 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1820 LHS, RHS, "cmp"); 1821 } 1822 1823 // If this is a vector comparison, sign extend the result to the appropriate 1824 // vector integer type and return it (don't convert to bool). 1825 if (LHSTy->isVectorType()) 1826 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 1827 1828 } else { 1829 // Complex Comparison: can only be an equality comparison. 1830 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 1831 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 1832 1833 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 1834 1835 Value *ResultR, *ResultI; 1836 if (CETy->isRealFloatingType()) { 1837 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1838 LHS.first, RHS.first, "cmp.r"); 1839 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1840 LHS.second, RHS.second, "cmp.i"); 1841 } else { 1842 // Complex comparisons can only be equality comparisons. As such, signed 1843 // and unsigned opcodes are the same. 1844 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1845 LHS.first, RHS.first, "cmp.r"); 1846 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1847 LHS.second, RHS.second, "cmp.i"); 1848 } 1849 1850 if (E->getOpcode() == BO_EQ) { 1851 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 1852 } else { 1853 assert(E->getOpcode() == BO_NE && 1854 "Complex comparison other than == or != ?"); 1855 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 1856 } 1857 } 1858 1859 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 1860} 1861 1862Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 1863 bool Ignore = TestAndClearIgnoreResultAssign(); 1864 1865 // __block variables need to have the rhs evaluated first, plus this should 1866 // improve codegen just a little. 1867 Value *RHS = Visit(E->getRHS()); 1868 LValue LHS = EmitCheckedLValue(E->getLHS()); 1869 1870 // Store the value into the LHS. Bit-fields are handled specially 1871 // because the result is altered by the store, i.e., [C99 6.5.16p1] 1872 // 'An assignment expression has the value of the left operand after 1873 // the assignment...'. 1874 if (LHS.isBitField()) 1875 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), 1876 &RHS); 1877 else 1878 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 1879 1880 // If the result is clearly ignored, return now. 1881 if (Ignore) 1882 return 0; 1883 1884 // Objective-C property assignment never reloads the value following a store. 1885 if (LHS.isPropertyRef() || LHS.isKVCRef()) 1886 return RHS; 1887 1888 // If the lvalue is non-volatile, return the computed value of the assignment. 1889 if (!LHS.isVolatileQualified()) 1890 return RHS; 1891 1892 // Otherwise, reload the value. 1893 return EmitLoadOfLValue(LHS, E->getType()); 1894} 1895 1896Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 1897 const llvm::Type *ResTy = ConvertType(E->getType()); 1898 1899 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 1900 // If we have 1 && X, just emit X without inserting the control flow. 1901 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1902 if (Cond == 1) { // If we have 1 && X, just emit X. 1903 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1904 // ZExt result to int or bool. 1905 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 1906 } 1907 1908 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 1909 if (!CGF.ContainsLabel(E->getRHS())) 1910 return llvm::Constant::getNullValue(ResTy); 1911 } 1912 1913 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 1914 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 1915 1916 // Branch on the LHS first. If it is false, go to the failure (cont) block. 1917 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 1918 1919 // Any edges into the ContBlock are now from an (indeterminate number of) 1920 // edges from this first condition. All of these values will be false. Start 1921 // setting up the PHI node in the Cont Block for this. 1922 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1923 "", ContBlock); 1924 PN->reserveOperandSpace(2); // Normal case, two inputs. 1925 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1926 PI != PE; ++PI) 1927 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 1928 1929 CGF.BeginConditionalBranch(); 1930 CGF.EmitBlock(RHSBlock); 1931 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1932 CGF.EndConditionalBranch(); 1933 1934 // Reaquire the RHS block, as there may be subblocks inserted. 1935 RHSBlock = Builder.GetInsertBlock(); 1936 1937 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1938 // into the phi node for the edge with the value of RHSCond. 1939 CGF.EmitBlock(ContBlock); 1940 PN->addIncoming(RHSCond, RHSBlock); 1941 1942 // ZExt result to int. 1943 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); 1944} 1945 1946Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 1947 const llvm::Type *ResTy = ConvertType(E->getType()); 1948 1949 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 1950 // If we have 0 || X, just emit X without inserting the control flow. 1951 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1952 if (Cond == -1) { // If we have 0 || X, just emit X. 1953 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1954 // ZExt result to int or bool. 1955 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 1956 } 1957 1958 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 1959 if (!CGF.ContainsLabel(E->getRHS())) 1960 return llvm::ConstantInt::get(ResTy, 1); 1961 } 1962 1963 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 1964 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 1965 1966 // Branch on the LHS first. If it is true, go to the success (cont) block. 1967 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 1968 1969 // Any edges into the ContBlock are now from an (indeterminate number of) 1970 // edges from this first condition. All of these values will be true. Start 1971 // setting up the PHI node in the Cont Block for this. 1972 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1973 "", ContBlock); 1974 PN->reserveOperandSpace(2); // Normal case, two inputs. 1975 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1976 PI != PE; ++PI) 1977 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 1978 1979 CGF.BeginConditionalBranch(); 1980 1981 // Emit the RHS condition as a bool value. 1982 CGF.EmitBlock(RHSBlock); 1983 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1984 1985 CGF.EndConditionalBranch(); 1986 1987 // Reaquire the RHS block, as there may be subblocks inserted. 1988 RHSBlock = Builder.GetInsertBlock(); 1989 1990 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1991 // into the phi node for the edge with the value of RHSCond. 1992 CGF.EmitBlock(ContBlock); 1993 PN->addIncoming(RHSCond, RHSBlock); 1994 1995 // ZExt result to int. 1996 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 1997} 1998 1999Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 2000 CGF.EmitStmt(E->getLHS()); 2001 CGF.EnsureInsertPoint(); 2002 return Visit(E->getRHS()); 2003} 2004 2005//===----------------------------------------------------------------------===// 2006// Other Operators 2007//===----------------------------------------------------------------------===// 2008 2009/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 2010/// expression is cheap enough and side-effect-free enough to evaluate 2011/// unconditionally instead of conditionally. This is used to convert control 2012/// flow into selects in some cases. 2013static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 2014 CodeGenFunction &CGF) { 2015 if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) 2016 return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr(), CGF); 2017 2018 // TODO: Allow anything we can constant fold to an integer or fp constant. 2019 if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || 2020 isa<FloatingLiteral>(E)) 2021 return true; 2022 2023 // Non-volatile automatic variables too, to get "cond ? X : Y" where 2024 // X and Y are local variables. 2025 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 2026 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 2027 if (VD->hasLocalStorage() && !(CGF.getContext() 2028 .getCanonicalType(VD->getType()) 2029 .isVolatileQualified())) 2030 return true; 2031 2032 return false; 2033} 2034 2035 2036Value *ScalarExprEmitter:: 2037VisitConditionalOperator(const ConditionalOperator *E) { 2038 TestAndClearIgnoreResultAssign(); 2039 // If the condition constant folds and can be elided, try to avoid emitting 2040 // the condition and the dead arm. 2041 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ 2042 Expr *Live = E->getLHS(), *Dead = E->getRHS(); 2043 if (Cond == -1) 2044 std::swap(Live, Dead); 2045 2046 // If the dead side doesn't have labels we need, and if the Live side isn't 2047 // the gnu missing ?: extension (which we could handle, but don't bother 2048 // to), just emit the Live part. 2049 if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part 2050 Live) // Live part isn't missing. 2051 return Visit(Live); 2052 } 2053 2054 2055 // If this is a really simple expression (like x ? 4 : 5), emit this as a 2056 // select instead of as control flow. We can only do this if it is cheap and 2057 // safe to evaluate the LHS and RHS unconditionally. 2058 if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS(), 2059 CGF) && 2060 isCheapEnoughToEvaluateUnconditionally(E->getRHS(), CGF)) { 2061 llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); 2062 llvm::Value *LHS = Visit(E->getLHS()); 2063 llvm::Value *RHS = Visit(E->getRHS()); 2064 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 2065 } 2066 2067 if (!E->getLHS() && CGF.getContext().getLangOptions().CPlusPlus) { 2068 // Does not support GNU missing condition extension in C++ yet (see #7726) 2069 CGF.ErrorUnsupported(E, "conditional operator with missing LHS"); 2070 return llvm::UndefValue::get(ConvertType(E->getType())); 2071 } 2072 2073 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 2074 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 2075 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 2076 Value *CondVal = 0; 2077 2078 // If we don't have the GNU missing condition extension, emit a branch on bool 2079 // the normal way. 2080 if (E->getLHS()) { 2081 // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for 2082 // the branch on bool. 2083 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); 2084 } else { 2085 // Otherwise, for the ?: extension, evaluate the conditional and then 2086 // convert it to bool the hard way. We do this explicitly because we need 2087 // the unconverted value for the missing middle value of the ?:. 2088 CondVal = CGF.EmitScalarExpr(E->getCond()); 2089 2090 // In some cases, EmitScalarConversion will delete the "CondVal" expression 2091 // if there are no extra uses (an optimization). Inhibit this by making an 2092 // extra dead use, because we're going to add a use of CondVal later. We 2093 // don't use the builder for this, because we don't want it to get optimized 2094 // away. This leaves dead code, but the ?: extension isn't common. 2095 new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", 2096 Builder.GetInsertBlock()); 2097 2098 Value *CondBoolVal = 2099 CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 2100 CGF.getContext().BoolTy); 2101 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 2102 } 2103 2104 CGF.BeginConditionalBranch(); 2105 CGF.EmitBlock(LHSBlock); 2106 2107 // Handle the GNU extension for missing LHS. 2108 Value *LHS; 2109 if (E->getLHS()) 2110 LHS = Visit(E->getLHS()); 2111 else // Perform promotions, to handle cases like "short ?: int" 2112 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); 2113 2114 CGF.EndConditionalBranch(); 2115 LHSBlock = Builder.GetInsertBlock(); 2116 CGF.EmitBranch(ContBlock); 2117 2118 CGF.BeginConditionalBranch(); 2119 CGF.EmitBlock(RHSBlock); 2120 2121 Value *RHS = Visit(E->getRHS()); 2122 CGF.EndConditionalBranch(); 2123 RHSBlock = Builder.GetInsertBlock(); 2124 CGF.EmitBranch(ContBlock); 2125 2126 CGF.EmitBlock(ContBlock); 2127 2128 // If the LHS or RHS is a throw expression, it will be legitimately null. 2129 if (!LHS) 2130 return RHS; 2131 if (!RHS) 2132 return LHS; 2133 2134 // Create a PHI node for the real part. 2135 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 2136 PN->reserveOperandSpace(2); 2137 PN->addIncoming(LHS, LHSBlock); 2138 PN->addIncoming(RHS, RHSBlock); 2139 return PN; 2140} 2141 2142Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 2143 return Visit(E->getChosenSubExpr(CGF.getContext())); 2144} 2145 2146Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 2147 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 2148 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 2149 2150 // If EmitVAArg fails, we fall back to the LLVM instruction. 2151 if (!ArgPtr) 2152 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 2153 2154 // FIXME Volatility. 2155 return Builder.CreateLoad(ArgPtr); 2156} 2157 2158Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { 2159 return CGF.BuildBlockLiteralTmp(BE); 2160} 2161 2162//===----------------------------------------------------------------------===// 2163// Entry Point into this File 2164//===----------------------------------------------------------------------===// 2165 2166/// EmitScalarExpr - Emit the computation of the specified expression of scalar 2167/// type, ignoring the result. 2168Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 2169 assert(E && !hasAggregateLLVMType(E->getType()) && 2170 "Invalid scalar expression to emit"); 2171 2172 return ScalarExprEmitter(*this, IgnoreResultAssign) 2173 .Visit(const_cast<Expr*>(E)); 2174} 2175 2176/// EmitScalarConversion - Emit a conversion from the specified type to the 2177/// specified destination type, both of which are LLVM scalar types. 2178Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 2179 QualType DstTy) { 2180 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 2181 "Invalid scalar expression to emit"); 2182 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 2183} 2184 2185/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 2186/// type to the specified destination type, where the destination type is an 2187/// LLVM scalar type. 2188Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 2189 QualType SrcTy, 2190 QualType DstTy) { 2191 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 2192 "Invalid complex -> scalar conversion"); 2193 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 2194 DstTy); 2195} 2196 2197 2198llvm::Value *CodeGenFunction:: 2199EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 2200 bool isInc, bool isPre) { 2201 return ScalarExprEmitter(*this).EmitScalarPrePostIncDec(E, LV, isInc, isPre); 2202} 2203 2204LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) { 2205 llvm::Value *V; 2206 // object->isa or (*object).isa 2207 // Generate code as for: *(Class*)object 2208 // build Class* type 2209 const llvm::Type *ClassPtrTy = ConvertType(E->getType()); 2210 2211 Expr *BaseExpr = E->getBase(); 2212 if (BaseExpr->isLvalue(getContext()) != Expr::LV_Valid) { 2213 V = CreateTempAlloca(ClassPtrTy, "resval"); 2214 llvm::Value *Src = EmitScalarExpr(BaseExpr); 2215 Builder.CreateStore(Src, V); 2216 V = ScalarExprEmitter(*this).EmitLoadOfLValue( 2217 MakeAddrLValue(V, E->getType()), E->getType()); 2218 } else { 2219 if (E->isArrow()) 2220 V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr); 2221 else 2222 V = EmitLValue(BaseExpr).getAddress(); 2223 } 2224 2225 // build Class* type 2226 ClassPtrTy = ClassPtrTy->getPointerTo(); 2227 V = Builder.CreateBitCast(V, ClassPtrTy); 2228 return MakeAddrLValue(V, E->getType()); 2229} 2230 2231 2232LValue CodeGenFunction::EmitCompoundAssignOperatorLValue( 2233 const CompoundAssignOperator *E) { 2234 ScalarExprEmitter Scalar(*this); 2235 Value *Result = 0; 2236 switch (E->getOpcode()) { 2237#define COMPOUND_OP(Op) \ 2238 case BO_##Op##Assign: \ 2239 return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \ 2240 Result) 2241 COMPOUND_OP(Mul); 2242 COMPOUND_OP(Div); 2243 COMPOUND_OP(Rem); 2244 COMPOUND_OP(Add); 2245 COMPOUND_OP(Sub); 2246 COMPOUND_OP(Shl); 2247 COMPOUND_OP(Shr); 2248 COMPOUND_OP(And); 2249 COMPOUND_OP(Xor); 2250 COMPOUND_OP(Or); 2251#undef COMPOUND_OP 2252 2253 case BO_PtrMemD: 2254 case BO_PtrMemI: 2255 case BO_Mul: 2256 case BO_Div: 2257 case BO_Rem: 2258 case BO_Add: 2259 case BO_Sub: 2260 case BO_Shl: 2261 case BO_Shr: 2262 case BO_LT: 2263 case BO_GT: 2264 case BO_LE: 2265 case BO_GE: 2266 case BO_EQ: 2267 case BO_NE: 2268 case BO_And: 2269 case BO_Xor: 2270 case BO_Or: 2271 case BO_LAnd: 2272 case BO_LOr: 2273 case BO_Assign: 2274 case BO_Comma: 2275 assert(false && "Not valid compound assignment operators"); 2276 break; 2277 } 2278 2279 llvm_unreachable("Unhandled compound assignment operator"); 2280} 2281