CGExprScalar.cpp revision 0dfd848fa4c9664852ba8c929a8bd3fce93ddca2
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(), E->getValue()); 282 } 283 284 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { 285 // C++ [expr.pseudo]p1: 286 // The result shall only be used as the operand for the function call 287 // operator (), and the result of such a call has type void. The only 288 // effect is the evaluation of the postfix-expression before the dot or 289 // arrow. 290 CGF.EmitScalarExpr(E->getBase()); 291 return 0; 292 } 293 294 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { 295 return EmitNullValue(E->getType()); 296 } 297 298 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { 299 CGF.EmitCXXThrowExpr(E); 300 return 0; 301 } 302 303 Value *VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) { 304 return llvm::ConstantInt::get(Builder.getInt1Ty(), E->getValue()); 305 } 306 307 // Binary Operators. 308 Value *EmitMul(const BinOpInfo &Ops) { 309 if (Ops.Ty->hasSignedIntegerRepresentation()) { 310 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 311 case LangOptions::SOB_Undefined: 312 return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul"); 313 case LangOptions::SOB_Defined: 314 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 315 case LangOptions::SOB_Trapping: 316 return EmitOverflowCheckedBinOp(Ops); 317 } 318 } 319 320 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 321 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 322 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 323 } 324 bool isTrapvOverflowBehavior() { 325 return CGF.getContext().getLangOptions().getSignedOverflowBehavior() 326 == LangOptions::SOB_Trapping; 327 } 328 /// Create a binary op that checks for overflow. 329 /// Currently only supports +, - and *. 330 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 331 // Emit the overflow BB when -ftrapv option is activated. 332 void EmitOverflowBB(llvm::BasicBlock *overflowBB) { 333 Builder.SetInsertPoint(overflowBB); 334 llvm::Function *Trap = CGF.CGM.getIntrinsic(llvm::Intrinsic::trap); 335 Builder.CreateCall(Trap); 336 Builder.CreateUnreachable(); 337 } 338 // Check for undefined division and modulus behaviors. 339 void EmitUndefinedBehaviorIntegerDivAndRemCheck(const BinOpInfo &Ops, 340 llvm::Value *Zero,bool isDiv); 341 Value *EmitDiv(const BinOpInfo &Ops); 342 Value *EmitRem(const BinOpInfo &Ops); 343 Value *EmitAdd(const BinOpInfo &Ops); 344 Value *EmitSub(const BinOpInfo &Ops); 345 Value *EmitShl(const BinOpInfo &Ops); 346 Value *EmitShr(const BinOpInfo &Ops); 347 Value *EmitAnd(const BinOpInfo &Ops) { 348 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 349 } 350 Value *EmitXor(const BinOpInfo &Ops) { 351 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 352 } 353 Value *EmitOr (const BinOpInfo &Ops) { 354 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 355 } 356 357 BinOpInfo EmitBinOps(const BinaryOperator *E); 358 LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E, 359 Value *(ScalarExprEmitter::*F)(const BinOpInfo &), 360 Value *&Result); 361 362 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 363 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 364 365 // Binary operators and binary compound assignment operators. 366#define HANDLEBINOP(OP) \ 367 Value *VisitBin ## OP(const BinaryOperator *E) { \ 368 return Emit ## OP(EmitBinOps(E)); \ 369 } \ 370 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 371 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 372 } 373 HANDLEBINOP(Mul) 374 HANDLEBINOP(Div) 375 HANDLEBINOP(Rem) 376 HANDLEBINOP(Add) 377 HANDLEBINOP(Sub) 378 HANDLEBINOP(Shl) 379 HANDLEBINOP(Shr) 380 HANDLEBINOP(And) 381 HANDLEBINOP(Xor) 382 HANDLEBINOP(Or) 383#undef HANDLEBINOP 384 385 // Comparisons. 386 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 387 unsigned SICmpOpc, unsigned FCmpOpc); 388#define VISITCOMP(CODE, UI, SI, FP) \ 389 Value *VisitBin##CODE(const BinaryOperator *E) { \ 390 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 391 llvm::FCmpInst::FP); } 392 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT) 393 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT) 394 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE) 395 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE) 396 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ) 397 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE) 398#undef VISITCOMP 399 400 Value *VisitBinAssign (const BinaryOperator *E); 401 402 Value *VisitBinLAnd (const BinaryOperator *E); 403 Value *VisitBinLOr (const BinaryOperator *E); 404 Value *VisitBinComma (const BinaryOperator *E); 405 406 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } 407 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); } 408 409 // Other Operators. 410 Value *VisitBlockExpr(const BlockExpr *BE); 411 Value *VisitConditionalOperator(const ConditionalOperator *CO); 412 Value *VisitChooseExpr(ChooseExpr *CE); 413 Value *VisitVAArgExpr(VAArgExpr *VE); 414 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 415 return CGF.EmitObjCStringLiteral(E); 416 } 417}; 418} // end anonymous namespace. 419 420//===----------------------------------------------------------------------===// 421// Utilities 422//===----------------------------------------------------------------------===// 423 424/// EmitConversionToBool - Convert the specified expression value to a 425/// boolean (i1) truth value. This is equivalent to "Val != 0". 426Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 427 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs"); 428 429 if (SrcType->isRealFloatingType()) { 430 // Compare against 0.0 for fp scalars. 431 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 432 return Builder.CreateFCmpUNE(Src, Zero, "tobool"); 433 } 434 435 if (const MemberPointerType *MPT = dyn_cast<MemberPointerType>(SrcType)) 436 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, Src, MPT); 437 438 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 439 "Unknown scalar type to convert"); 440 441 // Because of the type rules of C, we often end up computing a logical value, 442 // then zero extending it to int, then wanting it as a logical value again. 443 // Optimize this common case. 444 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) { 445 if (ZI->getOperand(0)->getType() == 446 llvm::Type::getInt1Ty(CGF.getLLVMContext())) { 447 Value *Result = ZI->getOperand(0); 448 // If there aren't any more uses, zap the instruction to save space. 449 // Note that there can be more uses, for example if this 450 // is the result of an assignment. 451 if (ZI->use_empty()) 452 ZI->eraseFromParent(); 453 return Result; 454 } 455 } 456 457 // Compare against an integer or pointer null. 458 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 459 return Builder.CreateICmpNE(Src, Zero, "tobool"); 460} 461 462/// EmitScalarConversion - Emit a conversion from the specified type to the 463/// specified destination type, both of which are LLVM scalar types. 464Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 465 QualType DstType) { 466 SrcType = CGF.getContext().getCanonicalType(SrcType); 467 DstType = CGF.getContext().getCanonicalType(DstType); 468 if (SrcType == DstType) return Src; 469 470 if (DstType->isVoidType()) return 0; 471 472 // Handle conversions to bool first, they are special: comparisons against 0. 473 if (DstType->isBooleanType()) 474 return EmitConversionToBool(Src, SrcType); 475 476 const llvm::Type *DstTy = ConvertType(DstType); 477 478 // Ignore conversions like int -> uint. 479 if (Src->getType() == DstTy) 480 return Src; 481 482 // Handle pointer conversions next: pointers can only be converted to/from 483 // other pointers and integers. Check for pointer types in terms of LLVM, as 484 // some native types (like Obj-C id) may map to a pointer type. 485 if (isa<llvm::PointerType>(DstTy)) { 486 // The source value may be an integer, or a pointer. 487 if (isa<llvm::PointerType>(Src->getType())) 488 return Builder.CreateBitCast(Src, DstTy, "conv"); 489 490 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 491 // First, convert to the correct width so that we control the kind of 492 // extension. 493 const llvm::Type *MiddleTy = CGF.IntPtrTy; 494 bool InputSigned = SrcType->isSignedIntegerType(); 495 llvm::Value* IntResult = 496 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 497 // Then, cast to pointer. 498 return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); 499 } 500 501 if (isa<llvm::PointerType>(Src->getType())) { 502 // Must be an ptr to int cast. 503 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 504 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 505 } 506 507 // A scalar can be splatted to an extended vector of the same element type 508 if (DstType->isExtVectorType() && !SrcType->isVectorType()) { 509 // Cast the scalar to element type 510 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType(); 511 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 512 513 // Insert the element in element zero of an undef vector 514 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 515 llvm::Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, 0); 516 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 517 518 // Splat the element across to all elements 519 llvm::SmallVector<llvm::Constant*, 16> Args; 520 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 521 for (unsigned i = 0; i < NumElements; i++) 522 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 0)); 523 524 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 525 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 526 return Yay; 527 } 528 529 // Allow bitcast from vector to integer/fp of the same size. 530 if (isa<llvm::VectorType>(Src->getType()) || 531 isa<llvm::VectorType>(DstTy)) 532 return Builder.CreateBitCast(Src, DstTy, "conv"); 533 534 // Finally, we have the arithmetic types: real int/float. 535 if (isa<llvm::IntegerType>(Src->getType())) { 536 bool InputSigned = SrcType->isSignedIntegerType(); 537 if (isa<llvm::IntegerType>(DstTy)) 538 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 539 else if (InputSigned) 540 return Builder.CreateSIToFP(Src, DstTy, "conv"); 541 else 542 return Builder.CreateUIToFP(Src, DstTy, "conv"); 543 } 544 545 assert(Src->getType()->isFloatingPointTy() && "Unknown real conversion"); 546 if (isa<llvm::IntegerType>(DstTy)) { 547 if (DstType->isSignedIntegerType()) 548 return Builder.CreateFPToSI(Src, DstTy, "conv"); 549 else 550 return Builder.CreateFPToUI(Src, DstTy, "conv"); 551 } 552 553 assert(DstTy->isFloatingPointTy() && "Unknown real conversion"); 554 if (DstTy->getTypeID() < Src->getType()->getTypeID()) 555 return Builder.CreateFPTrunc(Src, DstTy, "conv"); 556 else 557 return Builder.CreateFPExt(Src, DstTy, "conv"); 558} 559 560/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 561/// type to the specified destination type, where the destination type is an 562/// LLVM scalar type. 563Value *ScalarExprEmitter:: 564EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 565 QualType SrcTy, QualType DstTy) { 566 // Get the source element type. 567 SrcTy = SrcTy->getAs<ComplexType>()->getElementType(); 568 569 // Handle conversions to bool first, they are special: comparisons against 0. 570 if (DstTy->isBooleanType()) { 571 // Complex != 0 -> (Real != 0) | (Imag != 0) 572 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 573 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 574 return Builder.CreateOr(Src.first, Src.second, "tobool"); 575 } 576 577 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 578 // the imaginary part of the complex value is discarded and the value of the 579 // real part is converted according to the conversion rules for the 580 // corresponding real type. 581 return EmitScalarConversion(Src.first, SrcTy, DstTy); 582} 583 584Value *ScalarExprEmitter::EmitNullValue(QualType Ty) { 585 if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>()) 586 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 587 588 return llvm::Constant::getNullValue(ConvertType(Ty)); 589} 590 591//===----------------------------------------------------------------------===// 592// Visitor Methods 593//===----------------------------------------------------------------------===// 594 595Value *ScalarExprEmitter::VisitExpr(Expr *E) { 596 CGF.ErrorUnsupported(E, "scalar expression"); 597 if (E->getType()->isVoidType()) 598 return 0; 599 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 600} 601 602Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 603 // Vector Mask Case 604 if (E->getNumSubExprs() == 2 || 605 (E->getNumSubExprs() == 3 && E->getExpr(2)->getType()->isVectorType())) { 606 Value *LHS = CGF.EmitScalarExpr(E->getExpr(0)); 607 Value *RHS = CGF.EmitScalarExpr(E->getExpr(1)); 608 Value *Mask; 609 610 const llvm::VectorType *LTy = cast<llvm::VectorType>(LHS->getType()); 611 unsigned LHSElts = LTy->getNumElements(); 612 613 if (E->getNumSubExprs() == 3) { 614 Mask = CGF.EmitScalarExpr(E->getExpr(2)); 615 616 // Shuffle LHS & RHS into one input vector. 617 llvm::SmallVector<llvm::Constant*, 32> concat; 618 for (unsigned i = 0; i != LHSElts; ++i) { 619 concat.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 2*i)); 620 concat.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 2*i+1)); 621 } 622 623 Value* CV = llvm::ConstantVector::get(concat.begin(), concat.size()); 624 LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat"); 625 LHSElts *= 2; 626 } else { 627 Mask = RHS; 628 } 629 630 const llvm::VectorType *MTy = cast<llvm::VectorType>(Mask->getType()); 631 llvm::Constant* EltMask; 632 633 // Treat vec3 like vec4. 634 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) 635 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 636 (1 << llvm::Log2_32(LHSElts+2))-1); 637 else if ((LHSElts == 3) && (E->getNumSubExprs() == 2)) 638 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 639 (1 << llvm::Log2_32(LHSElts+1))-1); 640 else 641 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 642 (1 << llvm::Log2_32(LHSElts))-1); 643 644 // Mask off the high bits of each shuffle index. 645 llvm::SmallVector<llvm::Constant *, 32> MaskV; 646 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) 647 MaskV.push_back(EltMask); 648 649 Value* MaskBits = llvm::ConstantVector::get(MaskV.begin(), MaskV.size()); 650 Mask = Builder.CreateAnd(Mask, MaskBits, "mask"); 651 652 // newv = undef 653 // mask = mask & maskbits 654 // for each elt 655 // n = extract mask i 656 // x = extract val n 657 // newv = insert newv, x, i 658 const llvm::VectorType *RTy = llvm::VectorType::get(LTy->getElementType(), 659 MTy->getNumElements()); 660 Value* NewV = llvm::UndefValue::get(RTy); 661 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) { 662 Value *Indx = llvm::ConstantInt::get(CGF.Int32Ty, i); 663 Indx = Builder.CreateExtractElement(Mask, Indx, "shuf_idx"); 664 Indx = Builder.CreateZExt(Indx, CGF.Int32Ty, "idx_zext"); 665 666 // Handle vec3 special since the index will be off by one for the RHS. 667 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) { 668 Value *cmpIndx, *newIndx; 669 cmpIndx = Builder.CreateICmpUGT(Indx, 670 llvm::ConstantInt::get(CGF.Int32Ty, 3), 671 "cmp_shuf_idx"); 672 newIndx = Builder.CreateSub(Indx, llvm::ConstantInt::get(CGF.Int32Ty,1), 673 "shuf_idx_adj"); 674 Indx = Builder.CreateSelect(cmpIndx, newIndx, Indx, "sel_shuf_idx"); 675 } 676 Value *VExt = Builder.CreateExtractElement(LHS, Indx, "shuf_elt"); 677 NewV = Builder.CreateInsertElement(NewV, VExt, Indx, "shuf_ins"); 678 } 679 return NewV; 680 } 681 682 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 683 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 684 685 // Handle vec3 special since the index will be off by one for the RHS. 686 llvm::SmallVector<llvm::Constant*, 32> indices; 687 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 688 llvm::Constant *C = cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i))); 689 const llvm::VectorType *VTy = cast<llvm::VectorType>(V1->getType()); 690 if (VTy->getNumElements() == 3) { 691 if (llvm::ConstantInt *CI = dyn_cast<llvm::ConstantInt>(C)) { 692 uint64_t cVal = CI->getZExtValue(); 693 if (cVal > 3) { 694 C = llvm::ConstantInt::get(C->getType(), cVal-1); 695 } 696 } 697 } 698 indices.push_back(C); 699 } 700 701 Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); 702 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 703} 704Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { 705 Expr::EvalResult Result; 706 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 707 if (E->isArrow()) 708 CGF.EmitScalarExpr(E->getBase()); 709 else 710 EmitLValue(E->getBase()); 711 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 712 } 713 return EmitLoadOfLValue(E); 714} 715 716Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 717 TestAndClearIgnoreResultAssign(); 718 719 // Emit subscript expressions in rvalue context's. For most cases, this just 720 // loads the lvalue formed by the subscript expr. However, we have to be 721 // careful, because the base of a vector subscript is occasionally an rvalue, 722 // so we can't get it as an lvalue. 723 if (!E->getBase()->getType()->isVectorType()) 724 return EmitLoadOfLValue(E); 725 726 // Handle the vector case. The base must be a vector, the index must be an 727 // integer value. 728 Value *Base = Visit(E->getBase()); 729 Value *Idx = Visit(E->getIdx()); 730 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerType(); 731 Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vecidxcast"); 732 return Builder.CreateExtractElement(Base, Idx, "vecext"); 733} 734 735static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, 736 unsigned Off, const llvm::Type *I32Ty) { 737 int MV = SVI->getMaskValue(Idx); 738 if (MV == -1) 739 return llvm::UndefValue::get(I32Ty); 740 return llvm::ConstantInt::get(I32Ty, Off+MV); 741} 742 743Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) { 744 bool Ignore = TestAndClearIgnoreResultAssign(); 745 (void)Ignore; 746 assert (Ignore == false && "init list ignored"); 747 unsigned NumInitElements = E->getNumInits(); 748 749 if (E->hadArrayRangeDesignator()) 750 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 751 752 const llvm::VectorType *VType = 753 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 754 755 // We have a scalar in braces. Just use the first element. 756 if (!VType) 757 return Visit(E->getInit(0)); 758 759 unsigned ResElts = VType->getNumElements(); 760 761 // Loop over initializers collecting the Value for each, and remembering 762 // whether the source was swizzle (ExtVectorElementExpr). This will allow 763 // us to fold the shuffle for the swizzle into the shuffle for the vector 764 // initializer, since LLVM optimizers generally do not want to touch 765 // shuffles. 766 unsigned CurIdx = 0; 767 bool VIsUndefShuffle = false; 768 llvm::Value *V = llvm::UndefValue::get(VType); 769 for (unsigned i = 0; i != NumInitElements; ++i) { 770 Expr *IE = E->getInit(i); 771 Value *Init = Visit(IE); 772 llvm::SmallVector<llvm::Constant*, 16> Args; 773 774 const llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType()); 775 776 // Handle scalar elements. If the scalar initializer is actually one 777 // element of a different vector of the same width, use shuffle instead of 778 // extract+insert. 779 if (!VVT) { 780 if (isa<ExtVectorElementExpr>(IE)) { 781 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init); 782 783 if (EI->getVectorOperandType()->getNumElements() == ResElts) { 784 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand()); 785 Value *LHS = 0, *RHS = 0; 786 if (CurIdx == 0) { 787 // insert into undef -> shuffle (src, undef) 788 Args.push_back(C); 789 for (unsigned j = 1; j != ResElts; ++j) 790 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 791 792 LHS = EI->getVectorOperand(); 793 RHS = V; 794 VIsUndefShuffle = true; 795 } else if (VIsUndefShuffle) { 796 // insert into undefshuffle && size match -> shuffle (v, src) 797 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V); 798 for (unsigned j = 0; j != CurIdx; ++j) 799 Args.push_back(getMaskElt(SVV, j, 0, CGF.Int32Ty)); 800 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 801 ResElts + C->getZExtValue())); 802 for (unsigned j = CurIdx + 1; j != ResElts; ++j) 803 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 804 805 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 806 RHS = EI->getVectorOperand(); 807 VIsUndefShuffle = false; 808 } 809 if (!Args.empty()) { 810 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 811 V = Builder.CreateShuffleVector(LHS, RHS, Mask); 812 ++CurIdx; 813 continue; 814 } 815 } 816 } 817 Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, CurIdx); 818 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 819 VIsUndefShuffle = false; 820 ++CurIdx; 821 continue; 822 } 823 824 unsigned InitElts = VVT->getNumElements(); 825 826 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's 827 // input is the same width as the vector being constructed, generate an 828 // optimized shuffle of the swizzle input into the result. 829 unsigned Offset = (CurIdx == 0) ? 0 : ResElts; 830 if (isa<ExtVectorElementExpr>(IE)) { 831 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init); 832 Value *SVOp = SVI->getOperand(0); 833 const llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType()); 834 835 if (OpTy->getNumElements() == ResElts) { 836 for (unsigned j = 0; j != CurIdx; ++j) { 837 // If the current vector initializer is a shuffle with undef, merge 838 // this shuffle directly into it. 839 if (VIsUndefShuffle) { 840 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0, 841 CGF.Int32Ty)); 842 } else { 843 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); 844 } 845 } 846 for (unsigned j = 0, je = InitElts; j != je; ++j) 847 Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty)); 848 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 849 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 850 851 if (VIsUndefShuffle) 852 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 853 854 Init = SVOp; 855 } 856 } 857 858 // Extend init to result vector length, and then shuffle its contribution 859 // to the vector initializer into V. 860 if (Args.empty()) { 861 for (unsigned j = 0; j != InitElts; ++j) 862 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); 863 for (unsigned j = InitElts; j != ResElts; ++j) 864 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 865 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 866 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), 867 Mask, "vext"); 868 869 Args.clear(); 870 for (unsigned j = 0; j != CurIdx; ++j) 871 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); 872 for (unsigned j = 0; j != InitElts; ++j) 873 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j+Offset)); 874 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 875 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 876 } 877 878 // If V is undef, make sure it ends up on the RHS of the shuffle to aid 879 // merging subsequent shuffles into this one. 880 if (CurIdx == 0) 881 std::swap(V, Init); 882 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 883 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); 884 VIsUndefShuffle = isa<llvm::UndefValue>(Init); 885 CurIdx += InitElts; 886 } 887 888 // FIXME: evaluate codegen vs. shuffling against constant null vector. 889 // Emit remaining default initializers. 890 const llvm::Type *EltTy = VType->getElementType(); 891 892 // Emit remaining default initializers 893 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { 894 Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, CurIdx); 895 llvm::Value *Init = llvm::Constant::getNullValue(EltTy); 896 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 897 } 898 return V; 899} 900 901static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { 902 const Expr *E = CE->getSubExpr(); 903 904 if (CE->getCastKind() == CK_UncheckedDerivedToBase) 905 return false; 906 907 if (isa<CXXThisExpr>(E)) { 908 // We always assume that 'this' is never null. 909 return false; 910 } 911 912 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { 913 // And that glvalue casts are never null. 914 if (ICE->getValueKind() != VK_RValue) 915 return false; 916 } 917 918 return true; 919} 920 921// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 922// have to handle a more broad range of conversions than explicit casts, as they 923// handle things like function to ptr-to-function decay etc. 924Value *ScalarExprEmitter::EmitCastExpr(CastExpr *CE) { 925 Expr *E = CE->getSubExpr(); 926 QualType DestTy = CE->getType(); 927 CastKind Kind = CE->getCastKind(); 928 929 if (!DestTy->isVoidType()) 930 TestAndClearIgnoreResultAssign(); 931 932 // Since almost all cast kinds apply to scalars, this switch doesn't have 933 // a default case, so the compiler will warn on a missing case. The cases 934 // are in the same order as in the CastKind enum. 935 switch (Kind) { 936 case CK_Unknown: 937 // FIXME: All casts should have a known kind! 938 //assert(0 && "Unknown cast kind!"); 939 break; 940 941 case CK_LValueBitCast: 942 case CK_ObjCObjectLValueCast: { 943 Value *V = EmitLValue(E).getAddress(); 944 V = Builder.CreateBitCast(V, 945 ConvertType(CGF.getContext().getPointerType(DestTy))); 946 return EmitLoadOfLValue(CGF.MakeAddrLValue(V, DestTy), DestTy); 947 } 948 949 case CK_AnyPointerToObjCPointerCast: 950 case CK_AnyPointerToBlockPointerCast: 951 case CK_BitCast: { 952 Value *Src = Visit(const_cast<Expr*>(E)); 953 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 954 } 955 case CK_NoOp: 956 case CK_UserDefinedConversion: 957 return Visit(const_cast<Expr*>(E)); 958 959 case CK_BaseToDerived: { 960 const CXXRecordDecl *DerivedClassDecl = 961 DestTy->getCXXRecordDeclForPointerType(); 962 963 return CGF.GetAddressOfDerivedClass(Visit(E), DerivedClassDecl, 964 CE->path_begin(), CE->path_end(), 965 ShouldNullCheckClassCastValue(CE)); 966 } 967 case CK_UncheckedDerivedToBase: 968 case CK_DerivedToBase: { 969 const RecordType *DerivedClassTy = 970 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 971 CXXRecordDecl *DerivedClassDecl = 972 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 973 974 return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl, 975 CE->path_begin(), CE->path_end(), 976 ShouldNullCheckClassCastValue(CE)); 977 } 978 case CK_Dynamic: { 979 Value *V = Visit(const_cast<Expr*>(E)); 980 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 981 return CGF.EmitDynamicCast(V, DCE); 982 } 983 case CK_ToUnion: 984 assert(0 && "Should be unreachable!"); 985 break; 986 987 case CK_ArrayToPointerDecay: { 988 assert(E->getType()->isArrayType() && 989 "Array to pointer decay must have array source type!"); 990 991 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 992 993 // Note that VLA pointers are always decayed, so we don't need to do 994 // anything here. 995 if (!E->getType()->isVariableArrayType()) { 996 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 997 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 998 ->getElementType()) && 999 "Expected pointer to array"); 1000 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 1001 } 1002 1003 return V; 1004 } 1005 case CK_FunctionToPointerDecay: 1006 return EmitLValue(E).getAddress(); 1007 1008 case CK_NullToMemberPointer: { 1009 // If the subexpression's type is the C++0x nullptr_t, emit the 1010 // subexpression, which may have side effects. 1011 if (E->getType()->isNullPtrType()) 1012 (void) Visit(E); 1013 1014 const MemberPointerType *MPT = CE->getType()->getAs<MemberPointerType>(); 1015 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 1016 } 1017 1018 case CK_BaseToDerivedMemberPointer: 1019 case CK_DerivedToBaseMemberPointer: { 1020 Value *Src = Visit(E); 1021 1022 // Note that the AST doesn't distinguish between checked and 1023 // unchecked member pointer conversions, so we always have to 1024 // implement checked conversions here. This is inefficient when 1025 // actual control flow may be required in order to perform the 1026 // check, which it is for data member pointers (but not member 1027 // function pointers on Itanium and ARM). 1028 return CGF.CGM.getCXXABI().EmitMemberPointerConversion(CGF, CE, Src); 1029 } 1030 1031 1032 case CK_ConstructorConversion: 1033 assert(0 && "Should be unreachable!"); 1034 break; 1035 1036 case CK_IntegralToPointer: { 1037 Value *Src = Visit(const_cast<Expr*>(E)); 1038 1039 // First, convert to the correct width so that we control the kind of 1040 // extension. 1041 const llvm::Type *MiddleTy = CGF.IntPtrTy; 1042 bool InputSigned = E->getType()->isSignedIntegerType(); 1043 llvm::Value* IntResult = 1044 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 1045 1046 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 1047 } 1048 case CK_PointerToIntegral: { 1049 Value *Src = Visit(const_cast<Expr*>(E)); 1050 1051 // Handle conversion to bool correctly. 1052 if (DestTy->isBooleanType()) 1053 return EmitScalarConversion(Src, E->getType(), DestTy); 1054 1055 return Builder.CreatePtrToInt(Src, ConvertType(DestTy)); 1056 } 1057 case CK_ToVoid: { 1058 if (E->Classify(CGF.getContext()).isGLValue()) { 1059 LValue LV = CGF.EmitLValue(E); 1060 if (LV.isPropertyRef()) 1061 CGF.EmitLoadOfPropertyRefLValue(LV, E->getType()); 1062 else if (LV.isKVCRef()) 1063 CGF.EmitLoadOfKVCRefLValue(LV, E->getType()); 1064 } 1065 else 1066 CGF.EmitAnyExpr(E, 0, false, true); 1067 return 0; 1068 } 1069 case CK_VectorSplat: { 1070 const llvm::Type *DstTy = ConvertType(DestTy); 1071 Value *Elt = Visit(const_cast<Expr*>(E)); 1072 1073 // Insert the element in element zero of an undef vector 1074 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 1075 llvm::Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, 0); 1076 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 1077 1078 // Splat the element across to all elements 1079 llvm::SmallVector<llvm::Constant*, 16> Args; 1080 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 1081 for (unsigned i = 0; i < NumElements; i++) 1082 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 0)); 1083 1084 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 1085 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 1086 return Yay; 1087 } 1088 case CK_IntegralCast: 1089 case CK_IntegralToFloating: 1090 case CK_FloatingToIntegral: 1091 case CK_FloatingCast: 1092 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 1093 1094 case CK_MemberPointerToBoolean: { 1095 llvm::Value *MemPtr = Visit(E); 1096 const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>(); 1097 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT); 1098 } 1099 } 1100 1101 // Handle cases where the source is an non-complex type. 1102 1103 if (!CGF.hasAggregateLLVMType(E->getType())) { 1104 Value *Src = Visit(const_cast<Expr*>(E)); 1105 1106 // Use EmitScalarConversion to perform the conversion. 1107 return EmitScalarConversion(Src, E->getType(), DestTy); 1108 } 1109 1110 if (E->getType()->isAnyComplexType()) { 1111 // Handle cases where the source is a complex type. 1112 bool IgnoreImag = true; 1113 bool IgnoreImagAssign = true; 1114 bool IgnoreReal = IgnoreResultAssign; 1115 bool IgnoreRealAssign = IgnoreResultAssign; 1116 if (DestTy->isBooleanType()) 1117 IgnoreImagAssign = IgnoreImag = false; 1118 else if (DestTy->isVoidType()) { 1119 IgnoreReal = IgnoreImag = false; 1120 IgnoreRealAssign = IgnoreImagAssign = true; 1121 } 1122 CodeGenFunction::ComplexPairTy V 1123 = CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign, 1124 IgnoreImagAssign); 1125 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 1126 } 1127 1128 // Okay, this is a cast from an aggregate. It must be a cast to void. Just 1129 // evaluate the result and return. 1130 CGF.EmitAggExpr(E, 0, false, true); 1131 return 0; 1132} 1133 1134Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 1135 return CGF.EmitCompoundStmt(*E->getSubStmt(), 1136 !E->getType()->isVoidType()).getScalarVal(); 1137} 1138 1139Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 1140 llvm::Value *V = CGF.GetAddrOfBlockDecl(E); 1141 if (E->getType().isObjCGCWeak()) 1142 return CGF.CGM.getObjCRuntime().EmitObjCWeakRead(CGF, V); 1143 return CGF.EmitLoadOfScalar(V, false, 0, E->getType()); 1144} 1145 1146//===----------------------------------------------------------------------===// 1147// Unary Operators 1148//===----------------------------------------------------------------------===// 1149 1150llvm::Value *ScalarExprEmitter:: 1151EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 1152 bool isInc, bool isPre) { 1153 1154 QualType ValTy = E->getSubExpr()->getType(); 1155 llvm::Value *InVal = EmitLoadOfLValue(LV, ValTy); 1156 1157 int AmountVal = isInc ? 1 : -1; 1158 1159 if (ValTy->isPointerType() && 1160 ValTy->getAs<PointerType>()->isVariableArrayType()) { 1161 // The amount of the addition/subtraction needs to account for the VLA size 1162 CGF.ErrorUnsupported(E, "VLA pointer inc/dec"); 1163 } 1164 1165 llvm::Value *NextVal; 1166 if (const llvm::PointerType *PT = 1167 dyn_cast<llvm::PointerType>(InVal->getType())) { 1168 llvm::Constant *Inc = llvm::ConstantInt::get(CGF.Int32Ty, AmountVal); 1169 if (!isa<llvm::FunctionType>(PT->getElementType())) { 1170 QualType PTEE = ValTy->getPointeeType(); 1171 if (const ObjCObjectType *OIT = PTEE->getAs<ObjCObjectType>()) { 1172 // Handle interface types, which are not represented with a concrete 1173 // type. 1174 int size = CGF.getContext().getTypeSize(OIT) / 8; 1175 if (!isInc) 1176 size = -size; 1177 Inc = llvm::ConstantInt::get(Inc->getType(), size); 1178 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1179 InVal = Builder.CreateBitCast(InVal, i8Ty); 1180 NextVal = Builder.CreateGEP(InVal, Inc, "add.ptr"); 1181 llvm::Value *lhs = LV.getAddress(); 1182 lhs = Builder.CreateBitCast(lhs, llvm::PointerType::getUnqual(i8Ty)); 1183 LV = CGF.MakeAddrLValue(lhs, ValTy); 1184 } else 1185 NextVal = Builder.CreateInBoundsGEP(InVal, Inc, "ptrincdec"); 1186 } else { 1187 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1188 NextVal = Builder.CreateBitCast(InVal, i8Ty, "tmp"); 1189 NextVal = Builder.CreateGEP(NextVal, Inc, "ptrincdec"); 1190 NextVal = Builder.CreateBitCast(NextVal, InVal->getType()); 1191 } 1192 } else if (InVal->getType()->isIntegerTy(1) && isInc) { 1193 // Bool++ is an interesting case, due to promotion rules, we get: 1194 // Bool++ -> Bool = Bool+1 -> Bool = (int)Bool+1 -> 1195 // Bool = ((int)Bool+1) != 0 1196 // An interesting aspect of this is that increment is always true. 1197 // Decrement does not have this property. 1198 NextVal = llvm::ConstantInt::getTrue(VMContext); 1199 } else if (isa<llvm::IntegerType>(InVal->getType())) { 1200 NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); 1201 1202 if (!ValTy->isSignedIntegerType()) 1203 // Unsigned integer inc is always two's complement. 1204 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1205 else { 1206 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1207 case LangOptions::SOB_Undefined: 1208 NextVal = Builder.CreateNSWAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1209 break; 1210 case LangOptions::SOB_Defined: 1211 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1212 break; 1213 case LangOptions::SOB_Trapping: 1214 BinOpInfo BinOp; 1215 BinOp.LHS = InVal; 1216 BinOp.RHS = NextVal; 1217 BinOp.Ty = E->getType(); 1218 BinOp.Opcode = BO_Add; 1219 BinOp.E = E; 1220 NextVal = EmitOverflowCheckedBinOp(BinOp); 1221 break; 1222 } 1223 } 1224 } else { 1225 // Add the inc/dec to the real part. 1226 if (InVal->getType()->isFloatTy()) 1227 NextVal = 1228 llvm::ConstantFP::get(VMContext, 1229 llvm::APFloat(static_cast<float>(AmountVal))); 1230 else if (InVal->getType()->isDoubleTy()) 1231 NextVal = 1232 llvm::ConstantFP::get(VMContext, 1233 llvm::APFloat(static_cast<double>(AmountVal))); 1234 else { 1235 llvm::APFloat F(static_cast<float>(AmountVal)); 1236 bool ignored; 1237 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, 1238 &ignored); 1239 NextVal = llvm::ConstantFP::get(VMContext, F); 1240 } 1241 NextVal = Builder.CreateFAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1242 } 1243 1244 // Store the updated result through the lvalue. 1245 if (LV.isBitField()) 1246 CGF.EmitStoreThroughBitfieldLValue(RValue::get(NextVal), LV, ValTy, &NextVal); 1247 else 1248 CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV, ValTy); 1249 1250 // If this is a postinc, return the value read from memory, otherwise use the 1251 // updated value. 1252 return isPre ? NextVal : InVal; 1253} 1254 1255 1256 1257Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1258 TestAndClearIgnoreResultAssign(); 1259 // Emit unary minus with EmitSub so we handle overflow cases etc. 1260 BinOpInfo BinOp; 1261 BinOp.RHS = Visit(E->getSubExpr()); 1262 1263 if (BinOp.RHS->getType()->isFPOrFPVectorTy()) 1264 BinOp.LHS = llvm::ConstantFP::getZeroValueForNegation(BinOp.RHS->getType()); 1265 else 1266 BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType()); 1267 BinOp.Ty = E->getType(); 1268 BinOp.Opcode = BO_Sub; 1269 BinOp.E = E; 1270 return EmitSub(BinOp); 1271} 1272 1273Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1274 TestAndClearIgnoreResultAssign(); 1275 Value *Op = Visit(E->getSubExpr()); 1276 return Builder.CreateNot(Op, "neg"); 1277} 1278 1279Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1280 // Compare operand to zero. 1281 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1282 1283 // Invert value. 1284 // TODO: Could dynamically modify easy computations here. For example, if 1285 // the operand is an icmp ne, turn into icmp eq. 1286 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1287 1288 // ZExt result to the expr type. 1289 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1290} 1291 1292Value *ScalarExprEmitter::VisitOffsetOfExpr(OffsetOfExpr *E) { 1293 // Try folding the offsetof to a constant. 1294 Expr::EvalResult EvalResult; 1295 if (E->Evaluate(EvalResult, CGF.getContext())) 1296 return llvm::ConstantInt::get(VMContext, EvalResult.Val.getInt()); 1297 1298 // Loop over the components of the offsetof to compute the value. 1299 unsigned n = E->getNumComponents(); 1300 const llvm::Type* ResultType = ConvertType(E->getType()); 1301 llvm::Value* Result = llvm::Constant::getNullValue(ResultType); 1302 QualType CurrentType = E->getTypeSourceInfo()->getType(); 1303 for (unsigned i = 0; i != n; ++i) { 1304 OffsetOfExpr::OffsetOfNode ON = E->getComponent(i); 1305 llvm::Value *Offset = 0; 1306 switch (ON.getKind()) { 1307 case OffsetOfExpr::OffsetOfNode::Array: { 1308 // Compute the index 1309 Expr *IdxExpr = E->getIndexExpr(ON.getArrayExprIndex()); 1310 llvm::Value* Idx = CGF.EmitScalarExpr(IdxExpr); 1311 bool IdxSigned = IdxExpr->getType()->isSignedIntegerType(); 1312 Idx = Builder.CreateIntCast(Idx, ResultType, IdxSigned, "conv"); 1313 1314 // Save the element type 1315 CurrentType = 1316 CGF.getContext().getAsArrayType(CurrentType)->getElementType(); 1317 1318 // Compute the element size 1319 llvm::Value* ElemSize = llvm::ConstantInt::get(ResultType, 1320 CGF.getContext().getTypeSizeInChars(CurrentType).getQuantity()); 1321 1322 // Multiply out to compute the result 1323 Offset = Builder.CreateMul(Idx, ElemSize); 1324 break; 1325 } 1326 1327 case OffsetOfExpr::OffsetOfNode::Field: { 1328 FieldDecl *MemberDecl = ON.getField(); 1329 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1330 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1331 1332 // Compute the index of the field in its parent. 1333 unsigned i = 0; 1334 // FIXME: It would be nice if we didn't have to loop here! 1335 for (RecordDecl::field_iterator Field = RD->field_begin(), 1336 FieldEnd = RD->field_end(); 1337 Field != FieldEnd; (void)++Field, ++i) { 1338 if (*Field == MemberDecl) 1339 break; 1340 } 1341 assert(i < RL.getFieldCount() && "offsetof field in wrong type"); 1342 1343 // Compute the offset to the field 1344 int64_t OffsetInt = RL.getFieldOffset(i) / 1345 CGF.getContext().getCharWidth(); 1346 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1347 1348 // Save the element type. 1349 CurrentType = MemberDecl->getType(); 1350 break; 1351 } 1352 1353 case OffsetOfExpr::OffsetOfNode::Identifier: 1354 llvm_unreachable("dependent __builtin_offsetof"); 1355 1356 case OffsetOfExpr::OffsetOfNode::Base: { 1357 if (ON.getBase()->isVirtual()) { 1358 CGF.ErrorUnsupported(E, "virtual base in offsetof"); 1359 continue; 1360 } 1361 1362 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1363 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1364 1365 // Save the element type. 1366 CurrentType = ON.getBase()->getType(); 1367 1368 // Compute the offset to the base. 1369 const RecordType *BaseRT = CurrentType->getAs<RecordType>(); 1370 CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl()); 1371 int64_t OffsetInt = RL.getBaseClassOffset(BaseRD) / 1372 CGF.getContext().getCharWidth(); 1373 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1374 break; 1375 } 1376 } 1377 Result = Builder.CreateAdd(Result, Offset); 1378 } 1379 return Result; 1380} 1381 1382/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of 1383/// argument of the sizeof expression as an integer. 1384Value * 1385ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { 1386 QualType TypeToSize = E->getTypeOfArgument(); 1387 if (E->isSizeOf()) { 1388 if (const VariableArrayType *VAT = 1389 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1390 if (E->isArgumentType()) { 1391 // sizeof(type) - make sure to emit the VLA size. 1392 CGF.EmitVLASize(TypeToSize); 1393 } else { 1394 // C99 6.5.3.4p2: If the argument is an expression of type 1395 // VLA, it is evaluated. 1396 CGF.EmitAnyExpr(E->getArgumentExpr()); 1397 } 1398 1399 return CGF.GetVLASize(VAT); 1400 } 1401 } 1402 1403 // If this isn't sizeof(vla), the result must be constant; use the constant 1404 // folding logic so we don't have to duplicate it here. 1405 Expr::EvalResult Result; 1406 E->Evaluate(Result, CGF.getContext()); 1407 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 1408} 1409 1410Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1411 Expr *Op = E->getSubExpr(); 1412 if (Op->getType()->isAnyComplexType()) 1413 return CGF.EmitComplexExpr(Op, false, true, false, true).first; 1414 return Visit(Op); 1415} 1416Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1417 Expr *Op = E->getSubExpr(); 1418 if (Op->getType()->isAnyComplexType()) 1419 return CGF.EmitComplexExpr(Op, true, false, true, false).second; 1420 1421 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1422 // effects are evaluated, but not the actual value. 1423 if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) 1424 CGF.EmitLValue(Op); 1425 else 1426 CGF.EmitScalarExpr(Op, true); 1427 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1428} 1429 1430//===----------------------------------------------------------------------===// 1431// Binary Operators 1432//===----------------------------------------------------------------------===// 1433 1434BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1435 TestAndClearIgnoreResultAssign(); 1436 BinOpInfo Result; 1437 Result.LHS = Visit(E->getLHS()); 1438 Result.RHS = Visit(E->getRHS()); 1439 Result.Ty = E->getType(); 1440 Result.Opcode = E->getOpcode(); 1441 Result.E = E; 1442 return Result; 1443} 1444 1445LValue ScalarExprEmitter::EmitCompoundAssignLValue( 1446 const CompoundAssignOperator *E, 1447 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &), 1448 Value *&Result) { 1449 QualType LHSTy = E->getLHS()->getType(); 1450 BinOpInfo OpInfo; 1451 1452 if (E->getComputationResultType()->isAnyComplexType()) { 1453 // This needs to go through the complex expression emitter, but it's a tad 1454 // complicated to do that... I'm leaving it out for now. (Note that we do 1455 // actually need the imaginary part of the RHS for multiplication and 1456 // division.) 1457 CGF.ErrorUnsupported(E, "complex compound assignment"); 1458 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType())); 1459 return LValue(); 1460 } 1461 1462 // Emit the RHS first. __block variables need to have the rhs evaluated 1463 // first, plus this should improve codegen a little. 1464 OpInfo.RHS = Visit(E->getRHS()); 1465 OpInfo.Ty = E->getComputationResultType(); 1466 OpInfo.Opcode = E->getOpcode(); 1467 OpInfo.E = E; 1468 // Load/convert the LHS. 1469 LValue LHSLV = EmitCheckedLValue(E->getLHS()); 1470 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 1471 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 1472 E->getComputationLHSType()); 1473 1474 // Expand the binary operator. 1475 Result = (this->*Func)(OpInfo); 1476 1477 // Convert the result back to the LHS type. 1478 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 1479 1480 // Store the result value into the LHS lvalue. Bit-fields are handled 1481 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 1482 // 'An assignment expression has the value of the left operand after the 1483 // assignment...'. 1484 if (LHSLV.isBitField()) 1485 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, 1486 &Result); 1487 else 1488 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); 1489 1490 return LHSLV; 1491} 1492 1493Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 1494 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 1495 bool Ignore = TestAndClearIgnoreResultAssign(); 1496 Value *RHS; 1497 LValue LHS = EmitCompoundAssignLValue(E, Func, RHS); 1498 1499 // If the result is clearly ignored, return now. 1500 if (Ignore) 1501 return 0; 1502 1503 // Objective-C property assignment never reloads the value following a store. 1504 if (LHS.isPropertyRef() || LHS.isKVCRef()) 1505 return RHS; 1506 1507 // If the lvalue is non-volatile, return the computed value of the assignment. 1508 if (!LHS.isVolatileQualified()) 1509 return RHS; 1510 1511 // Otherwise, reload the value. 1512 return EmitLoadOfLValue(LHS, E->getType()); 1513} 1514 1515void ScalarExprEmitter::EmitUndefinedBehaviorIntegerDivAndRemCheck( 1516 const BinOpInfo &Ops, 1517 llvm::Value *Zero, bool isDiv) { 1518 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); 1519 llvm::BasicBlock *contBB = 1520 CGF.createBasicBlock(isDiv ? "div.cont" : "rem.cont", CGF.CurFn); 1521 1522 const llvm::IntegerType *Ty = cast<llvm::IntegerType>(Zero->getType()); 1523 1524 if (Ops.Ty->hasSignedIntegerRepresentation()) { 1525 llvm::Value *IntMin = 1526 llvm::ConstantInt::get(VMContext, 1527 llvm::APInt::getSignedMinValue(Ty->getBitWidth())); 1528 llvm::Value *NegOne = llvm::ConstantInt::get(Ty, -1ULL); 1529 1530 llvm::Value *Cond1 = Builder.CreateICmpEQ(Ops.RHS, Zero); 1531 llvm::Value *LHSCmp = Builder.CreateICmpEQ(Ops.LHS, IntMin); 1532 llvm::Value *RHSCmp = Builder.CreateICmpEQ(Ops.RHS, NegOne); 1533 llvm::Value *Cond2 = Builder.CreateAnd(LHSCmp, RHSCmp, "and"); 1534 Builder.CreateCondBr(Builder.CreateOr(Cond1, Cond2, "or"), 1535 overflowBB, contBB); 1536 } else { 1537 CGF.Builder.CreateCondBr(Builder.CreateICmpEQ(Ops.RHS, Zero), 1538 overflowBB, contBB); 1539 } 1540 EmitOverflowBB(overflowBB); 1541 Builder.SetInsertPoint(contBB); 1542} 1543 1544Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 1545 if (isTrapvOverflowBehavior()) { 1546 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 1547 1548 if (Ops.Ty->isIntegerType()) 1549 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, true); 1550 else if (Ops.Ty->isRealFloatingType()) { 1551 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", 1552 CGF.CurFn); 1553 llvm::BasicBlock *DivCont = CGF.createBasicBlock("div.cont", CGF.CurFn); 1554 CGF.Builder.CreateCondBr(Builder.CreateFCmpOEQ(Ops.RHS, Zero), 1555 overflowBB, DivCont); 1556 EmitOverflowBB(overflowBB); 1557 Builder.SetInsertPoint(DivCont); 1558 } 1559 } 1560 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1561 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 1562 else if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1563 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 1564 else 1565 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 1566} 1567 1568Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 1569 // Rem in C can't be a floating point type: C99 6.5.5p2. 1570 if (isTrapvOverflowBehavior()) { 1571 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 1572 1573 if (Ops.Ty->isIntegerType()) 1574 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, false); 1575 } 1576 1577 if (Ops.Ty->isUnsignedIntegerType()) 1578 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 1579 else 1580 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 1581} 1582 1583Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 1584 unsigned IID; 1585 unsigned OpID = 0; 1586 1587 switch (Ops.Opcode) { 1588 case BO_Add: 1589 case BO_AddAssign: 1590 OpID = 1; 1591 IID = llvm::Intrinsic::sadd_with_overflow; 1592 break; 1593 case BO_Sub: 1594 case BO_SubAssign: 1595 OpID = 2; 1596 IID = llvm::Intrinsic::ssub_with_overflow; 1597 break; 1598 case BO_Mul: 1599 case BO_MulAssign: 1600 OpID = 3; 1601 IID = llvm::Intrinsic::smul_with_overflow; 1602 break; 1603 default: 1604 assert(false && "Unsupported operation for overflow detection"); 1605 IID = 0; 1606 } 1607 OpID <<= 1; 1608 OpID |= 1; 1609 1610 const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1611 1612 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1); 1613 1614 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1615 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1616 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1617 1618 // Branch in case of overflow. 1619 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); 1620 llvm::BasicBlock *continueBB = CGF.createBasicBlock("nooverflow", CGF.CurFn); 1621 1622 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1623 1624 // Handle overflow with llvm.trap. 1625 // TODO: it would be better to generate one of these blocks per function. 1626 EmitOverflowBB(overflowBB); 1627 1628 // Continue on. 1629 Builder.SetInsertPoint(continueBB); 1630 return result; 1631} 1632 1633Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 1634 if (!Ops.Ty->isAnyPointerType()) { 1635 if (Ops.Ty->hasSignedIntegerRepresentation()) { 1636 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1637 case LangOptions::SOB_Undefined: 1638 return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add"); 1639 case LangOptions::SOB_Defined: 1640 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1641 case LangOptions::SOB_Trapping: 1642 return EmitOverflowCheckedBinOp(Ops); 1643 } 1644 } 1645 1646 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1647 return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add"); 1648 1649 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1650 } 1651 1652 // Must have binary (not unary) expr here. Unary pointer decrement doesn't 1653 // use this path. 1654 const BinaryOperator *BinOp = cast<BinaryOperator>(Ops.E); 1655 1656 if (Ops.Ty->isPointerType() && 1657 Ops.Ty->getAs<PointerType>()->isVariableArrayType()) { 1658 // The amount of the addition needs to account for the VLA size 1659 CGF.ErrorUnsupported(BinOp, "VLA pointer addition"); 1660 } 1661 1662 Value *Ptr, *Idx; 1663 Expr *IdxExp; 1664 const PointerType *PT = BinOp->getLHS()->getType()->getAs<PointerType>(); 1665 const ObjCObjectPointerType *OPT = 1666 BinOp->getLHS()->getType()->getAs<ObjCObjectPointerType>(); 1667 if (PT || OPT) { 1668 Ptr = Ops.LHS; 1669 Idx = Ops.RHS; 1670 IdxExp = BinOp->getRHS(); 1671 } else { // int + pointer 1672 PT = BinOp->getRHS()->getType()->getAs<PointerType>(); 1673 OPT = BinOp->getRHS()->getType()->getAs<ObjCObjectPointerType>(); 1674 assert((PT || OPT) && "Invalid add expr"); 1675 Ptr = Ops.RHS; 1676 Idx = Ops.LHS; 1677 IdxExp = BinOp->getLHS(); 1678 } 1679 1680 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1681 if (Width < CGF.LLVMPointerWidth) { 1682 // Zero or sign extend the pointer value based on whether the index is 1683 // signed or not. 1684 const llvm::Type *IdxType = CGF.IntPtrTy; 1685 if (IdxExp->getType()->isSignedIntegerType()) 1686 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1687 else 1688 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1689 } 1690 const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType(); 1691 // Handle interface types, which are not represented with a concrete type. 1692 if (const ObjCObjectType *OIT = ElementType->getAs<ObjCObjectType>()) { 1693 llvm::Value *InterfaceSize = 1694 llvm::ConstantInt::get(Idx->getType(), 1695 CGF.getContext().getTypeSizeInChars(OIT).getQuantity()); 1696 Idx = Builder.CreateMul(Idx, InterfaceSize); 1697 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1698 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1699 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1700 return Builder.CreateBitCast(Res, Ptr->getType()); 1701 } 1702 1703 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 1704 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 1705 // future proof. 1706 if (ElementType->isVoidType() || ElementType->isFunctionType()) { 1707 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1708 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1709 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1710 return Builder.CreateBitCast(Res, Ptr->getType()); 1711 } 1712 1713 return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr"); 1714} 1715 1716Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 1717 if (!isa<llvm::PointerType>(Ops.LHS->getType())) { 1718 if (Ops.Ty->hasSignedIntegerRepresentation()) { 1719 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1720 case LangOptions::SOB_Undefined: 1721 return Builder.CreateNSWSub(Ops.LHS, Ops.RHS, "sub"); 1722 case LangOptions::SOB_Defined: 1723 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1724 case LangOptions::SOB_Trapping: 1725 return EmitOverflowCheckedBinOp(Ops); 1726 } 1727 } 1728 1729 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1730 return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub"); 1731 1732 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1733 } 1734 1735 // Must have binary (not unary) expr here. Unary pointer increment doesn't 1736 // use this path. 1737 const BinaryOperator *BinOp = cast<BinaryOperator>(Ops.E); 1738 1739 if (BinOp->getLHS()->getType()->isPointerType() && 1740 BinOp->getLHS()->getType()->getAs<PointerType>()->isVariableArrayType()) { 1741 // The amount of the addition needs to account for the VLA size for 1742 // ptr-int 1743 // The amount of the division needs to account for the VLA size for 1744 // ptr-ptr. 1745 CGF.ErrorUnsupported(BinOp, "VLA pointer subtraction"); 1746 } 1747 1748 const QualType LHSType = BinOp->getLHS()->getType(); 1749 const QualType LHSElementType = LHSType->getPointeeType(); 1750 if (!isa<llvm::PointerType>(Ops.RHS->getType())) { 1751 // pointer - int 1752 Value *Idx = Ops.RHS; 1753 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1754 if (Width < CGF.LLVMPointerWidth) { 1755 // Zero or sign extend the pointer value based on whether the index is 1756 // signed or not. 1757 const llvm::Type *IdxType = CGF.IntPtrTy; 1758 if (BinOp->getRHS()->getType()->isSignedIntegerType()) 1759 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1760 else 1761 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1762 } 1763 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); 1764 1765 // Handle interface types, which are not represented with a concrete type. 1766 if (const ObjCObjectType *OIT = LHSElementType->getAs<ObjCObjectType>()) { 1767 llvm::Value *InterfaceSize = 1768 llvm::ConstantInt::get(Idx->getType(), 1769 CGF.getContext(). 1770 getTypeSizeInChars(OIT).getQuantity()); 1771 Idx = Builder.CreateMul(Idx, InterfaceSize); 1772 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1773 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1774 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr"); 1775 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1776 } 1777 1778 // Explicitly handle GNU void* and function pointer arithmetic 1779 // extensions. The GNU void* casts amount to no-ops since our void* type is 1780 // i8*, but this is future proof. 1781 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1782 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1783 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1784 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); 1785 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1786 } 1787 1788 return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr"); 1789 } else { 1790 // pointer - pointer 1791 Value *LHS = Ops.LHS; 1792 Value *RHS = Ops.RHS; 1793 1794 CharUnits ElementSize; 1795 1796 // Handle GCC extension for pointer arithmetic on void* and function pointer 1797 // types. 1798 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1799 ElementSize = CharUnits::One(); 1800 } else { 1801 ElementSize = CGF.getContext().getTypeSizeInChars(LHSElementType); 1802 } 1803 1804 const llvm::Type *ResultType = ConvertType(Ops.Ty); 1805 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 1806 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 1807 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 1808 1809 // Optimize out the shift for element size of 1. 1810 if (ElementSize.isOne()) 1811 return BytesBetween; 1812 1813 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 1814 // pointer difference in C is only defined in the case where both operands 1815 // are pointing to elements of an array. 1816 Value *BytesPerElt = 1817 llvm::ConstantInt::get(ResultType, ElementSize.getQuantity()); 1818 return Builder.CreateExactSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 1819 } 1820} 1821 1822Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 1823 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1824 // RHS to the same size as the LHS. 1825 Value *RHS = Ops.RHS; 1826 if (Ops.LHS->getType() != RHS->getType()) 1827 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1828 1829 if (CGF.CatchUndefined 1830 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1831 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1832 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1833 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1834 llvm::ConstantInt::get(RHS->getType(), Width)), 1835 Cont, CGF.getTrapBB()); 1836 CGF.EmitBlock(Cont); 1837 } 1838 1839 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 1840} 1841 1842Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 1843 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1844 // RHS to the same size as the LHS. 1845 Value *RHS = Ops.RHS; 1846 if (Ops.LHS->getType() != RHS->getType()) 1847 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1848 1849 if (CGF.CatchUndefined 1850 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1851 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1852 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1853 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1854 llvm::ConstantInt::get(RHS->getType(), Width)), 1855 Cont, CGF.getTrapBB()); 1856 CGF.EmitBlock(Cont); 1857 } 1858 1859 if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1860 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 1861 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 1862} 1863 1864Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 1865 unsigned SICmpOpc, unsigned FCmpOpc) { 1866 TestAndClearIgnoreResultAssign(); 1867 Value *Result; 1868 QualType LHSTy = E->getLHS()->getType(); 1869 if (const MemberPointerType *MPT = LHSTy->getAs<MemberPointerType>()) { 1870 assert(E->getOpcode() == BO_EQ || 1871 E->getOpcode() == BO_NE); 1872 Value *LHS = CGF.EmitScalarExpr(E->getLHS()); 1873 Value *RHS = CGF.EmitScalarExpr(E->getRHS()); 1874 Result = CGF.CGM.getCXXABI().EmitMemberPointerComparison( 1875 CGF, LHS, RHS, MPT, E->getOpcode() == BO_NE); 1876 } else if (!LHSTy->isAnyComplexType()) { 1877 Value *LHS = Visit(E->getLHS()); 1878 Value *RHS = Visit(E->getRHS()); 1879 1880 if (LHS->getType()->isFPOrFPVectorTy()) { 1881 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 1882 LHS, RHS, "cmp"); 1883 } else if (LHSTy->hasSignedIntegerRepresentation()) { 1884 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 1885 LHS, RHS, "cmp"); 1886 } else { 1887 // Unsigned integers and pointers. 1888 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1889 LHS, RHS, "cmp"); 1890 } 1891 1892 // If this is a vector comparison, sign extend the result to the appropriate 1893 // vector integer type and return it (don't convert to bool). 1894 if (LHSTy->isVectorType()) 1895 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 1896 1897 } else { 1898 // Complex Comparison: can only be an equality comparison. 1899 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 1900 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 1901 1902 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 1903 1904 Value *ResultR, *ResultI; 1905 if (CETy->isRealFloatingType()) { 1906 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1907 LHS.first, RHS.first, "cmp.r"); 1908 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1909 LHS.second, RHS.second, "cmp.i"); 1910 } else { 1911 // Complex comparisons can only be equality comparisons. As such, signed 1912 // and unsigned opcodes are the same. 1913 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1914 LHS.first, RHS.first, "cmp.r"); 1915 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1916 LHS.second, RHS.second, "cmp.i"); 1917 } 1918 1919 if (E->getOpcode() == BO_EQ) { 1920 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 1921 } else { 1922 assert(E->getOpcode() == BO_NE && 1923 "Complex comparison other than == or != ?"); 1924 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 1925 } 1926 } 1927 1928 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 1929} 1930 1931Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 1932 bool Ignore = TestAndClearIgnoreResultAssign(); 1933 1934 // __block variables need to have the rhs evaluated first, plus this should 1935 // improve codegen just a little. 1936 Value *RHS = Visit(E->getRHS()); 1937 LValue LHS = EmitCheckedLValue(E->getLHS()); 1938 1939 // Store the value into the LHS. Bit-fields are handled specially 1940 // because the result is altered by the store, i.e., [C99 6.5.16p1] 1941 // 'An assignment expression has the value of the left operand after 1942 // the assignment...'. 1943 if (LHS.isBitField()) 1944 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), 1945 &RHS); 1946 else 1947 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 1948 1949 // If the result is clearly ignored, return now. 1950 if (Ignore) 1951 return 0; 1952 1953 // Objective-C property assignment never reloads the value following a store. 1954 if (LHS.isPropertyRef() || LHS.isKVCRef()) 1955 return RHS; 1956 1957 // If the lvalue is non-volatile, return the computed value of the assignment. 1958 if (!LHS.isVolatileQualified()) 1959 return RHS; 1960 1961 // Otherwise, reload the value. 1962 return EmitLoadOfLValue(LHS, E->getType()); 1963} 1964 1965Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 1966 const llvm::Type *ResTy = ConvertType(E->getType()); 1967 1968 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 1969 // If we have 1 && X, just emit X without inserting the control flow. 1970 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1971 if (Cond == 1) { // If we have 1 && X, just emit X. 1972 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1973 // ZExt result to int or bool. 1974 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 1975 } 1976 1977 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 1978 if (!CGF.ContainsLabel(E->getRHS())) 1979 return llvm::Constant::getNullValue(ResTy); 1980 } 1981 1982 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 1983 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 1984 1985 // Branch on the LHS first. If it is false, go to the failure (cont) block. 1986 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 1987 1988 // Any edges into the ContBlock are now from an (indeterminate number of) 1989 // edges from this first condition. All of these values will be false. Start 1990 // setting up the PHI node in the Cont Block for this. 1991 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 1992 "", ContBlock); 1993 PN->reserveOperandSpace(2); // Normal case, two inputs. 1994 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1995 PI != PE; ++PI) 1996 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 1997 1998 CGF.BeginConditionalBranch(); 1999 CGF.EmitBlock(RHSBlock); 2000 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2001 CGF.EndConditionalBranch(); 2002 2003 // Reaquire the RHS block, as there may be subblocks inserted. 2004 RHSBlock = Builder.GetInsertBlock(); 2005 2006 // Emit an unconditional branch from this block to ContBlock. Insert an entry 2007 // into the phi node for the edge with the value of RHSCond. 2008 CGF.EmitBlock(ContBlock); 2009 PN->addIncoming(RHSCond, RHSBlock); 2010 2011 // ZExt result to int. 2012 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); 2013} 2014 2015Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 2016 const llvm::Type *ResTy = ConvertType(E->getType()); 2017 2018 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 2019 // If we have 0 || X, just emit X without inserting the control flow. 2020 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 2021 if (Cond == -1) { // If we have 0 || X, just emit X. 2022 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2023 // ZExt result to int or bool. 2024 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 2025 } 2026 2027 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 2028 if (!CGF.ContainsLabel(E->getRHS())) 2029 return llvm::ConstantInt::get(ResTy, 1); 2030 } 2031 2032 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 2033 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 2034 2035 // Branch on the LHS first. If it is true, go to the success (cont) block. 2036 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 2037 2038 // Any edges into the ContBlock are now from an (indeterminate number of) 2039 // edges from this first condition. All of these values will be true. Start 2040 // setting up the PHI node in the Cont Block for this. 2041 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2042 "", ContBlock); 2043 PN->reserveOperandSpace(2); // Normal case, two inputs. 2044 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 2045 PI != PE; ++PI) 2046 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 2047 2048 CGF.BeginConditionalBranch(); 2049 2050 // Emit the RHS condition as a bool value. 2051 CGF.EmitBlock(RHSBlock); 2052 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2053 2054 CGF.EndConditionalBranch(); 2055 2056 // Reaquire the RHS block, as there may be subblocks inserted. 2057 RHSBlock = Builder.GetInsertBlock(); 2058 2059 // Emit an unconditional branch from this block to ContBlock. Insert an entry 2060 // into the phi node for the edge with the value of RHSCond. 2061 CGF.EmitBlock(ContBlock); 2062 PN->addIncoming(RHSCond, RHSBlock); 2063 2064 // ZExt result to int. 2065 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 2066} 2067 2068Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 2069 CGF.EmitStmt(E->getLHS()); 2070 CGF.EnsureInsertPoint(); 2071 return Visit(E->getRHS()); 2072} 2073 2074//===----------------------------------------------------------------------===// 2075// Other Operators 2076//===----------------------------------------------------------------------===// 2077 2078/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 2079/// expression is cheap enough and side-effect-free enough to evaluate 2080/// unconditionally instead of conditionally. This is used to convert control 2081/// flow into selects in some cases. 2082static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 2083 CodeGenFunction &CGF) { 2084 if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) 2085 return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr(), CGF); 2086 2087 // TODO: Allow anything we can constant fold to an integer or fp constant. 2088 if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || 2089 isa<FloatingLiteral>(E)) 2090 return true; 2091 2092 // Non-volatile automatic variables too, to get "cond ? X : Y" where 2093 // X and Y are local variables. 2094 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 2095 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 2096 if (VD->hasLocalStorage() && !(CGF.getContext() 2097 .getCanonicalType(VD->getType()) 2098 .isVolatileQualified())) 2099 return true; 2100 2101 return false; 2102} 2103 2104 2105Value *ScalarExprEmitter:: 2106VisitConditionalOperator(const ConditionalOperator *E) { 2107 TestAndClearIgnoreResultAssign(); 2108 // If the condition constant folds and can be elided, try to avoid emitting 2109 // the condition and the dead arm. 2110 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ 2111 Expr *Live = E->getLHS(), *Dead = E->getRHS(); 2112 if (Cond == -1) 2113 std::swap(Live, Dead); 2114 2115 // If the dead side doesn't have labels we need, and if the Live side isn't 2116 // the gnu missing ?: extension (which we could handle, but don't bother 2117 // to), just emit the Live part. 2118 if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part 2119 Live) // Live part isn't missing. 2120 return Visit(Live); 2121 } 2122 2123 2124 // If this is a really simple expression (like x ? 4 : 5), emit this as a 2125 // select instead of as control flow. We can only do this if it is cheap and 2126 // safe to evaluate the LHS and RHS unconditionally. 2127 if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS(), 2128 CGF) && 2129 isCheapEnoughToEvaluateUnconditionally(E->getRHS(), CGF)) { 2130 llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); 2131 llvm::Value *LHS = Visit(E->getLHS()); 2132 llvm::Value *RHS = Visit(E->getRHS()); 2133 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 2134 } 2135 2136 if (!E->getLHS() && CGF.getContext().getLangOptions().CPlusPlus) { 2137 // Does not support GNU missing condition extension in C++ yet (see #7726) 2138 CGF.ErrorUnsupported(E, "conditional operator with missing LHS"); 2139 return llvm::UndefValue::get(ConvertType(E->getType())); 2140 } 2141 2142 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 2143 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 2144 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 2145 Value *CondVal = 0; 2146 2147 // If we don't have the GNU missing condition extension, emit a branch on bool 2148 // the normal way. 2149 if (E->getLHS()) { 2150 // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for 2151 // the branch on bool. 2152 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); 2153 } else { 2154 // Otherwise, for the ?: extension, evaluate the conditional and then 2155 // convert it to bool the hard way. We do this explicitly because we need 2156 // the unconverted value for the missing middle value of the ?:. 2157 CondVal = CGF.EmitScalarExpr(E->getCond()); 2158 2159 // In some cases, EmitScalarConversion will delete the "CondVal" expression 2160 // if there are no extra uses (an optimization). Inhibit this by making an 2161 // extra dead use, because we're going to add a use of CondVal later. We 2162 // don't use the builder for this, because we don't want it to get optimized 2163 // away. This leaves dead code, but the ?: extension isn't common. 2164 new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", 2165 Builder.GetInsertBlock()); 2166 2167 Value *CondBoolVal = 2168 CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 2169 CGF.getContext().BoolTy); 2170 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 2171 } 2172 2173 CGF.BeginConditionalBranch(); 2174 CGF.EmitBlock(LHSBlock); 2175 2176 // Handle the GNU extension for missing LHS. 2177 Value *LHS; 2178 if (E->getLHS()) 2179 LHS = Visit(E->getLHS()); 2180 else // Perform promotions, to handle cases like "short ?: int" 2181 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); 2182 2183 CGF.EndConditionalBranch(); 2184 LHSBlock = Builder.GetInsertBlock(); 2185 CGF.EmitBranch(ContBlock); 2186 2187 CGF.BeginConditionalBranch(); 2188 CGF.EmitBlock(RHSBlock); 2189 2190 Value *RHS = Visit(E->getRHS()); 2191 CGF.EndConditionalBranch(); 2192 RHSBlock = Builder.GetInsertBlock(); 2193 CGF.EmitBranch(ContBlock); 2194 2195 CGF.EmitBlock(ContBlock); 2196 2197 // If the LHS or RHS is a throw expression, it will be legitimately null. 2198 if (!LHS) 2199 return RHS; 2200 if (!RHS) 2201 return LHS; 2202 2203 // Create a PHI node for the real part. 2204 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 2205 PN->reserveOperandSpace(2); 2206 PN->addIncoming(LHS, LHSBlock); 2207 PN->addIncoming(RHS, RHSBlock); 2208 return PN; 2209} 2210 2211Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 2212 return Visit(E->getChosenSubExpr(CGF.getContext())); 2213} 2214 2215Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 2216 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 2217 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 2218 2219 // If EmitVAArg fails, we fall back to the LLVM instruction. 2220 if (!ArgPtr) 2221 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 2222 2223 // FIXME Volatility. 2224 return Builder.CreateLoad(ArgPtr); 2225} 2226 2227Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { 2228 return CGF.BuildBlockLiteralTmp(BE); 2229} 2230 2231//===----------------------------------------------------------------------===// 2232// Entry Point into this File 2233//===----------------------------------------------------------------------===// 2234 2235/// EmitScalarExpr - Emit the computation of the specified expression of scalar 2236/// type, ignoring the result. 2237Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 2238 assert(E && !hasAggregateLLVMType(E->getType()) && 2239 "Invalid scalar expression to emit"); 2240 2241 return ScalarExprEmitter(*this, IgnoreResultAssign) 2242 .Visit(const_cast<Expr*>(E)); 2243} 2244 2245/// EmitScalarConversion - Emit a conversion from the specified type to the 2246/// specified destination type, both of which are LLVM scalar types. 2247Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 2248 QualType DstTy) { 2249 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 2250 "Invalid scalar expression to emit"); 2251 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 2252} 2253 2254/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 2255/// type to the specified destination type, where the destination type is an 2256/// LLVM scalar type. 2257Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 2258 QualType SrcTy, 2259 QualType DstTy) { 2260 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 2261 "Invalid complex -> scalar conversion"); 2262 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 2263 DstTy); 2264} 2265 2266 2267llvm::Value *CodeGenFunction:: 2268EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 2269 bool isInc, bool isPre) { 2270 return ScalarExprEmitter(*this).EmitScalarPrePostIncDec(E, LV, isInc, isPre); 2271} 2272 2273LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) { 2274 llvm::Value *V; 2275 // object->isa or (*object).isa 2276 // Generate code as for: *(Class*)object 2277 // build Class* type 2278 const llvm::Type *ClassPtrTy = ConvertType(E->getType()); 2279 2280 Expr *BaseExpr = E->getBase(); 2281 if (BaseExpr->isLvalue(getContext()) != Expr::LV_Valid) { 2282 V = CreateTempAlloca(ClassPtrTy, "resval"); 2283 llvm::Value *Src = EmitScalarExpr(BaseExpr); 2284 Builder.CreateStore(Src, V); 2285 V = ScalarExprEmitter(*this).EmitLoadOfLValue( 2286 MakeAddrLValue(V, E->getType()), E->getType()); 2287 } else { 2288 if (E->isArrow()) 2289 V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr); 2290 else 2291 V = EmitLValue(BaseExpr).getAddress(); 2292 } 2293 2294 // build Class* type 2295 ClassPtrTy = ClassPtrTy->getPointerTo(); 2296 V = Builder.CreateBitCast(V, ClassPtrTy); 2297 return MakeAddrLValue(V, E->getType()); 2298} 2299 2300 2301LValue CodeGenFunction::EmitCompoundAssignOperatorLValue( 2302 const CompoundAssignOperator *E) { 2303 ScalarExprEmitter Scalar(*this); 2304 Value *Result = 0; 2305 switch (E->getOpcode()) { 2306#define COMPOUND_OP(Op) \ 2307 case BO_##Op##Assign: \ 2308 return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \ 2309 Result) 2310 COMPOUND_OP(Mul); 2311 COMPOUND_OP(Div); 2312 COMPOUND_OP(Rem); 2313 COMPOUND_OP(Add); 2314 COMPOUND_OP(Sub); 2315 COMPOUND_OP(Shl); 2316 COMPOUND_OP(Shr); 2317 COMPOUND_OP(And); 2318 COMPOUND_OP(Xor); 2319 COMPOUND_OP(Or); 2320#undef COMPOUND_OP 2321 2322 case BO_PtrMemD: 2323 case BO_PtrMemI: 2324 case BO_Mul: 2325 case BO_Div: 2326 case BO_Rem: 2327 case BO_Add: 2328 case BO_Sub: 2329 case BO_Shl: 2330 case BO_Shr: 2331 case BO_LT: 2332 case BO_GT: 2333 case BO_LE: 2334 case BO_GE: 2335 case BO_EQ: 2336 case BO_NE: 2337 case BO_And: 2338 case BO_Xor: 2339 case BO_Or: 2340 case BO_LAnd: 2341 case BO_LOr: 2342 case BO_Assign: 2343 case BO_Comma: 2344 assert(false && "Not valid compound assignment operators"); 2345 break; 2346 } 2347 2348 llvm_unreachable("Unhandled compound assignment operator"); 2349} 2350