CGExprScalar.cpp revision b418d74c11498b7e1044103131e2e3be4d63512e
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 "clang/Frontend/CodeGenOptions.h" 15#include "CodeGenFunction.h" 16#include "CGCXXABI.h" 17#include "CGObjCRuntime.h" 18#include "CodeGenModule.h" 19#include "CGDebugInfo.h" 20#include "clang/AST/ASTContext.h" 21#include "clang/AST/DeclObjC.h" 22#include "clang/AST/RecordLayout.h" 23#include "clang/AST/StmtVisitor.h" 24#include "clang/Basic/TargetInfo.h" 25#include "llvm/Constants.h" 26#include "llvm/Function.h" 27#include "llvm/GlobalVariable.h" 28#include "llvm/Intrinsics.h" 29#include "llvm/Module.h" 30#include "llvm/Support/CFG.h" 31#include "llvm/Target/TargetData.h" 32#include <cstdarg> 33 34using namespace clang; 35using namespace CodeGen; 36using llvm::Value; 37 38//===----------------------------------------------------------------------===// 39// Scalar Expression Emitter 40//===----------------------------------------------------------------------===// 41 42namespace { 43struct BinOpInfo { 44 Value *LHS; 45 Value *RHS; 46 QualType Ty; // Computation Type. 47 BinaryOperator::Opcode Opcode; // Opcode of BinOp to perform 48 const Expr *E; // Entire expr, for error unsupported. May not be binop. 49}; 50 51static bool MustVisitNullValue(const Expr *E) { 52 // If a null pointer expression's type is the C++0x nullptr_t, then 53 // it's not necessarily a simple constant and it must be evaluated 54 // for its potential side effects. 55 return E->getType()->isNullPtrType(); 56} 57 58class ScalarExprEmitter 59 : public StmtVisitor<ScalarExprEmitter, Value*> { 60 CodeGenFunction &CGF; 61 CGBuilderTy &Builder; 62 bool IgnoreResultAssign; 63 llvm::LLVMContext &VMContext; 64public: 65 66 ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false) 67 : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira), 68 VMContext(cgf.getLLVMContext()) { 69 } 70 71 //===--------------------------------------------------------------------===// 72 // Utilities 73 //===--------------------------------------------------------------------===// 74 75 bool TestAndClearIgnoreResultAssign() { 76 bool I = IgnoreResultAssign; 77 IgnoreResultAssign = false; 78 return I; 79 } 80 81 const llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); } 82 LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); } 83 LValue EmitCheckedLValue(const Expr *E) { return CGF.EmitCheckedLValue(E); } 84 85 Value *EmitLoadOfLValue(LValue LV, QualType T) { 86 return CGF.EmitLoadOfLValue(LV, T).getScalarVal(); 87 } 88 89 /// EmitLoadOfLValue - Given an expression with complex type that represents a 90 /// value l-value, this method emits the address of the l-value, then loads 91 /// and returns the result. 92 Value *EmitLoadOfLValue(const Expr *E) { 93 return EmitLoadOfLValue(EmitCheckedLValue(E), E->getType()); 94 } 95 96 /// EmitConversionToBool - Convert the specified expression value to a 97 /// boolean (i1) truth value. This is equivalent to "Val != 0". 98 Value *EmitConversionToBool(Value *Src, QualType DstTy); 99 100 /// EmitScalarConversion - Emit a conversion from the specified type to the 101 /// specified destination type, both of which are LLVM scalar types. 102 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); 103 104 /// EmitComplexToScalarConversion - Emit a conversion from the specified 105 /// complex type to the specified destination type, where the destination type 106 /// is an LLVM scalar type. 107 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 108 QualType SrcTy, QualType DstTy); 109 110 /// EmitNullValue - Emit a value that corresponds to null for the given type. 111 Value *EmitNullValue(QualType Ty); 112 113 /// EmitFloatToBoolConversion - Perform an FP to boolean conversion. 114 Value *EmitFloatToBoolConversion(Value *V) { 115 // Compare against 0.0 for fp scalars. 116 llvm::Value *Zero = llvm::Constant::getNullValue(V->getType()); 117 return Builder.CreateFCmpUNE(V, Zero, "tobool"); 118 } 119 120 /// EmitPointerToBoolConversion - Perform a pointer to boolean conversion. 121 Value *EmitPointerToBoolConversion(Value *V) { 122 Value *Zero = llvm::ConstantPointerNull::get( 123 cast<llvm::PointerType>(V->getType())); 124 return Builder.CreateICmpNE(V, Zero, "tobool"); 125 } 126 127 Value *EmitIntToBoolConversion(Value *V) { 128 // Because of the type rules of C, we often end up computing a 129 // logical value, then zero extending it to int, then wanting it 130 // as a logical value again. Optimize this common case. 131 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(V)) { 132 if (ZI->getOperand(0)->getType() == Builder.getInt1Ty()) { 133 Value *Result = ZI->getOperand(0); 134 // If there aren't any more uses, zap the instruction to save space. 135 // Note that there can be more uses, for example if this 136 // is the result of an assignment. 137 if (ZI->use_empty()) 138 ZI->eraseFromParent(); 139 return Result; 140 } 141 } 142 143 const llvm::IntegerType *Ty = cast<llvm::IntegerType>(V->getType()); 144 Value *Zero = llvm::ConstantInt::get(Ty, 0); 145 return Builder.CreateICmpNE(V, Zero, "tobool"); 146 } 147 148 //===--------------------------------------------------------------------===// 149 // Visitor Methods 150 //===--------------------------------------------------------------------===// 151 152 Value *Visit(Expr *E) { 153 llvm::DenseMap<const Expr *, llvm::Value *>::iterator I = 154 CGF.ConditionalSaveExprs.find(E); 155 if (I != CGF.ConditionalSaveExprs.end()) 156 return I->second; 157 158 return StmtVisitor<ScalarExprEmitter, Value*>::Visit(E); 159 } 160 161 Value *VisitStmt(Stmt *S) { 162 S->dump(CGF.getContext().getSourceManager()); 163 assert(0 && "Stmt can't have complex result type!"); 164 return 0; 165 } 166 Value *VisitExpr(Expr *S); 167 168 Value *VisitParenExpr(ParenExpr *PE) { 169 return Visit(PE->getSubExpr()); 170 } 171 172 // Leaves. 173 Value *VisitIntegerLiteral(const IntegerLiteral *E) { 174 return llvm::ConstantInt::get(VMContext, E->getValue()); 175 } 176 Value *VisitFloatingLiteral(const FloatingLiteral *E) { 177 return llvm::ConstantFP::get(VMContext, E->getValue()); 178 } 179 Value *VisitCharacterLiteral(const CharacterLiteral *E) { 180 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 181 } 182 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 183 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 184 } 185 Value *VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) { 186 return EmitNullValue(E->getType()); 187 } 188 Value *VisitGNUNullExpr(const GNUNullExpr *E) { 189 return EmitNullValue(E->getType()); 190 } 191 Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { 192 return llvm::ConstantInt::get(ConvertType(E->getType()), 193 CGF.getContext().typesAreCompatible( 194 E->getArgType1(), E->getArgType2())); 195 } 196 Value *VisitOffsetOfExpr(OffsetOfExpr *E); 197 Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); 198 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 199 llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel()); 200 return Builder.CreateBitCast(V, ConvertType(E->getType())); 201 } 202 203 // l-values. 204 Value *VisitDeclRefExpr(DeclRefExpr *E) { 205 Expr::EvalResult Result; 206 if (!E->Evaluate(Result, CGF.getContext())) 207 return EmitLoadOfLValue(E); 208 209 assert(!Result.HasSideEffects && "Constant declref with side-effect?!"); 210 211 llvm::Constant *C; 212 if (Result.Val.isInt()) { 213 C = llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 214 } else if (Result.Val.isFloat()) { 215 C = llvm::ConstantFP::get(VMContext, Result.Val.getFloat()); 216 } else { 217 return EmitLoadOfLValue(E); 218 } 219 220 // Make sure we emit a debug reference to the global variable. 221 if (VarDecl *VD = dyn_cast<VarDecl>(E->getDecl())) { 222 if (!CGF.getContext().DeclMustBeEmitted(VD)) 223 CGF.EmitDeclRefExprDbgValue(E, C); 224 } else if (isa<EnumConstantDecl>(E->getDecl())) { 225 CGF.EmitDeclRefExprDbgValue(E, C); 226 } 227 228 return C; 229 } 230 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 231 return CGF.EmitObjCSelectorExpr(E); 232 } 233 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 234 return CGF.EmitObjCProtocolExpr(E); 235 } 236 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 237 return EmitLoadOfLValue(E); 238 } 239 Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { 240 return EmitLoadOfLValue(E); 241 } 242 Value *VisitObjCImplicitSetterGetterRefExpr( 243 ObjCImplicitSetterGetterRefExpr *E) { 244 return EmitLoadOfLValue(E); 245 } 246 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 247 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 248 } 249 250 Value *VisitObjCIsaExpr(ObjCIsaExpr *E) { 251 LValue LV = CGF.EmitObjCIsaExpr(E); 252 Value *V = CGF.EmitLoadOfLValue(LV, E->getType()).getScalarVal(); 253 return V; 254 } 255 256 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 257 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 258 Value *VisitMemberExpr(MemberExpr *E); 259 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 260 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 261 return EmitLoadOfLValue(E); 262 } 263 264 Value *VisitInitListExpr(InitListExpr *E); 265 266 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { 267 return CGF.CGM.EmitNullConstant(E->getType()); 268 } 269 Value *VisitCastExpr(CastExpr *E) { 270 // Make sure to evaluate VLA bounds now so that we have them for later. 271 if (E->getType()->isVariablyModifiedType()) 272 CGF.EmitVLASize(E->getType()); 273 274 return EmitCastExpr(E); 275 } 276 Value *EmitCastExpr(CastExpr *E); 277 278 Value *VisitCallExpr(const CallExpr *E) { 279 if (E->getCallReturnType()->isReferenceType()) 280 return EmitLoadOfLValue(E); 281 282 return CGF.EmitCallExpr(E).getScalarVal(); 283 } 284 285 Value *VisitStmtExpr(const StmtExpr *E); 286 287 Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E); 288 289 // Unary Operators. 290 Value *VisitUnaryPostDec(const UnaryOperator *E) { 291 LValue LV = EmitLValue(E->getSubExpr()); 292 return EmitScalarPrePostIncDec(E, LV, false, false); 293 } 294 Value *VisitUnaryPostInc(const UnaryOperator *E) { 295 LValue LV = EmitLValue(E->getSubExpr()); 296 return EmitScalarPrePostIncDec(E, LV, true, false); 297 } 298 Value *VisitUnaryPreDec(const UnaryOperator *E) { 299 LValue LV = EmitLValue(E->getSubExpr()); 300 return EmitScalarPrePostIncDec(E, LV, false, true); 301 } 302 Value *VisitUnaryPreInc(const UnaryOperator *E) { 303 LValue LV = EmitLValue(E->getSubExpr()); 304 return EmitScalarPrePostIncDec(E, LV, true, true); 305 } 306 307 llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 308 bool isInc, bool isPre); 309 310 311 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 312 // If the sub-expression is an instance member reference, 313 // EmitDeclRefLValue will magically emit it with the appropriate 314 // value as the "address". 315 return EmitLValue(E->getSubExpr()).getAddress(); 316 } 317 Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } 318 Value *VisitUnaryPlus(const UnaryOperator *E) { 319 // This differs from gcc, though, most likely due to a bug in gcc. 320 TestAndClearIgnoreResultAssign(); 321 return Visit(E->getSubExpr()); 322 } 323 Value *VisitUnaryMinus (const UnaryOperator *E); 324 Value *VisitUnaryNot (const UnaryOperator *E); 325 Value *VisitUnaryLNot (const UnaryOperator *E); 326 Value *VisitUnaryReal (const UnaryOperator *E); 327 Value *VisitUnaryImag (const UnaryOperator *E); 328 Value *VisitUnaryExtension(const UnaryOperator *E) { 329 return Visit(E->getSubExpr()); 330 } 331 332 // C++ 333 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 334 return Visit(DAE->getExpr()); 335 } 336 Value *VisitCXXThisExpr(CXXThisExpr *TE) { 337 return CGF.LoadCXXThis(); 338 } 339 340 Value *VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) { 341 return CGF.EmitCXXExprWithTemporaries(E).getScalarVal(); 342 } 343 Value *VisitCXXNewExpr(const CXXNewExpr *E) { 344 return CGF.EmitCXXNewExpr(E); 345 } 346 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { 347 CGF.EmitCXXDeleteExpr(E); 348 return 0; 349 } 350 Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) { 351 return llvm::ConstantInt::get(Builder.getInt1Ty(), E->getValue()); 352 } 353 354 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { 355 // C++ [expr.pseudo]p1: 356 // The result shall only be used as the operand for the function call 357 // operator (), and the result of such a call has type void. The only 358 // effect is the evaluation of the postfix-expression before the dot or 359 // arrow. 360 CGF.EmitScalarExpr(E->getBase()); 361 return 0; 362 } 363 364 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { 365 return EmitNullValue(E->getType()); 366 } 367 368 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { 369 CGF.EmitCXXThrowExpr(E); 370 return 0; 371 } 372 373 Value *VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) { 374 return llvm::ConstantInt::get(Builder.getInt1Ty(), E->getValue()); 375 } 376 377 // Binary Operators. 378 Value *EmitMul(const BinOpInfo &Ops) { 379 if (Ops.Ty->hasSignedIntegerRepresentation()) { 380 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 381 case LangOptions::SOB_Undefined: 382 return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul"); 383 case LangOptions::SOB_Defined: 384 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 385 case LangOptions::SOB_Trapping: 386 return EmitOverflowCheckedBinOp(Ops); 387 } 388 } 389 390 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 391 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 392 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 393 } 394 bool isTrapvOverflowBehavior() { 395 return CGF.getContext().getLangOptions().getSignedOverflowBehavior() 396 == LangOptions::SOB_Trapping; 397 } 398 /// Create a binary op that checks for overflow. 399 /// Currently only supports +, - and *. 400 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 401 // Emit the overflow BB when -ftrapv option is activated. 402 void EmitOverflowBB(llvm::BasicBlock *overflowBB) { 403 Builder.SetInsertPoint(overflowBB); 404 llvm::Function *Trap = CGF.CGM.getIntrinsic(llvm::Intrinsic::trap); 405 Builder.CreateCall(Trap); 406 Builder.CreateUnreachable(); 407 } 408 // Check for undefined division and modulus behaviors. 409 void EmitUndefinedBehaviorIntegerDivAndRemCheck(const BinOpInfo &Ops, 410 llvm::Value *Zero,bool isDiv); 411 Value *EmitDiv(const BinOpInfo &Ops); 412 Value *EmitRem(const BinOpInfo &Ops); 413 Value *EmitAdd(const BinOpInfo &Ops); 414 Value *EmitSub(const BinOpInfo &Ops); 415 Value *EmitShl(const BinOpInfo &Ops); 416 Value *EmitShr(const BinOpInfo &Ops); 417 Value *EmitAnd(const BinOpInfo &Ops) { 418 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 419 } 420 Value *EmitXor(const BinOpInfo &Ops) { 421 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 422 } 423 Value *EmitOr (const BinOpInfo &Ops) { 424 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 425 } 426 427 BinOpInfo EmitBinOps(const BinaryOperator *E); 428 LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E, 429 Value *(ScalarExprEmitter::*F)(const BinOpInfo &), 430 Value *&Result); 431 432 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 433 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 434 435 // Binary operators and binary compound assignment operators. 436#define HANDLEBINOP(OP) \ 437 Value *VisitBin ## OP(const BinaryOperator *E) { \ 438 return Emit ## OP(EmitBinOps(E)); \ 439 } \ 440 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 441 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 442 } 443 HANDLEBINOP(Mul) 444 HANDLEBINOP(Div) 445 HANDLEBINOP(Rem) 446 HANDLEBINOP(Add) 447 HANDLEBINOP(Sub) 448 HANDLEBINOP(Shl) 449 HANDLEBINOP(Shr) 450 HANDLEBINOP(And) 451 HANDLEBINOP(Xor) 452 HANDLEBINOP(Or) 453#undef HANDLEBINOP 454 455 // Comparisons. 456 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 457 unsigned SICmpOpc, unsigned FCmpOpc); 458#define VISITCOMP(CODE, UI, SI, FP) \ 459 Value *VisitBin##CODE(const BinaryOperator *E) { \ 460 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 461 llvm::FCmpInst::FP); } 462 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT) 463 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT) 464 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE) 465 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE) 466 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ) 467 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE) 468#undef VISITCOMP 469 470 Value *VisitBinAssign (const BinaryOperator *E); 471 472 Value *VisitBinLAnd (const BinaryOperator *E); 473 Value *VisitBinLOr (const BinaryOperator *E); 474 Value *VisitBinComma (const BinaryOperator *E); 475 476 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } 477 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); } 478 479 // Other Operators. 480 Value *VisitBlockExpr(const BlockExpr *BE); 481 Value *VisitConditionalOperator(const ConditionalOperator *CO); 482 Value *VisitChooseExpr(ChooseExpr *CE); 483 Value *VisitVAArgExpr(VAArgExpr *VE); 484 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 485 return CGF.EmitObjCStringLiteral(E); 486 } 487}; 488} // end anonymous namespace. 489 490//===----------------------------------------------------------------------===// 491// Utilities 492//===----------------------------------------------------------------------===// 493 494/// EmitConversionToBool - Convert the specified expression value to a 495/// boolean (i1) truth value. This is equivalent to "Val != 0". 496Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 497 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs"); 498 499 if (SrcType->isRealFloatingType()) 500 return EmitFloatToBoolConversion(Src); 501 502 if (const MemberPointerType *MPT = dyn_cast<MemberPointerType>(SrcType)) 503 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, Src, MPT); 504 505 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 506 "Unknown scalar type to convert"); 507 508 if (isa<llvm::IntegerType>(Src->getType())) 509 return EmitIntToBoolConversion(Src); 510 511 assert(isa<llvm::PointerType>(Src->getType())); 512 return EmitPointerToBoolConversion(Src); 513} 514 515/// EmitScalarConversion - Emit a conversion from the specified type to the 516/// specified destination type, both of which are LLVM scalar types. 517Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 518 QualType DstType) { 519 SrcType = CGF.getContext().getCanonicalType(SrcType); 520 DstType = CGF.getContext().getCanonicalType(DstType); 521 if (SrcType == DstType) return Src; 522 523 if (DstType->isVoidType()) return 0; 524 525 // Handle conversions to bool first, they are special: comparisons against 0. 526 if (DstType->isBooleanType()) 527 return EmitConversionToBool(Src, SrcType); 528 529 const llvm::Type *DstTy = ConvertType(DstType); 530 531 // Ignore conversions like int -> uint. 532 if (Src->getType() == DstTy) 533 return Src; 534 535 // Handle pointer conversions next: pointers can only be converted to/from 536 // other pointers and integers. Check for pointer types in terms of LLVM, as 537 // some native types (like Obj-C id) may map to a pointer type. 538 if (isa<llvm::PointerType>(DstTy)) { 539 // The source value may be an integer, or a pointer. 540 if (isa<llvm::PointerType>(Src->getType())) 541 return Builder.CreateBitCast(Src, DstTy, "conv"); 542 543 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 544 // First, convert to the correct width so that we control the kind of 545 // extension. 546 const llvm::Type *MiddleTy = CGF.IntPtrTy; 547 bool InputSigned = SrcType->isSignedIntegerType(); 548 llvm::Value* IntResult = 549 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 550 // Then, cast to pointer. 551 return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); 552 } 553 554 if (isa<llvm::PointerType>(Src->getType())) { 555 // Must be an ptr to int cast. 556 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 557 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 558 } 559 560 // A scalar can be splatted to an extended vector of the same element type 561 if (DstType->isExtVectorType() && !SrcType->isVectorType()) { 562 // Cast the scalar to element type 563 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType(); 564 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 565 566 // Insert the element in element zero of an undef vector 567 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 568 llvm::Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, 0); 569 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 570 571 // Splat the element across to all elements 572 llvm::SmallVector<llvm::Constant*, 16> Args; 573 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 574 for (unsigned i = 0; i < NumElements; i++) 575 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 0)); 576 577 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 578 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 579 return Yay; 580 } 581 582 // Allow bitcast from vector to integer/fp of the same size. 583 if (isa<llvm::VectorType>(Src->getType()) || 584 isa<llvm::VectorType>(DstTy)) 585 return Builder.CreateBitCast(Src, DstTy, "conv"); 586 587 // Finally, we have the arithmetic types: real int/float. 588 if (isa<llvm::IntegerType>(Src->getType())) { 589 bool InputSigned = SrcType->isSignedIntegerType(); 590 if (isa<llvm::IntegerType>(DstTy)) 591 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 592 else if (InputSigned) 593 return Builder.CreateSIToFP(Src, DstTy, "conv"); 594 else 595 return Builder.CreateUIToFP(Src, DstTy, "conv"); 596 } 597 598 assert(Src->getType()->isFloatingPointTy() && "Unknown real conversion"); 599 if (isa<llvm::IntegerType>(DstTy)) { 600 if (DstType->isSignedIntegerType()) 601 return Builder.CreateFPToSI(Src, DstTy, "conv"); 602 else 603 return Builder.CreateFPToUI(Src, DstTy, "conv"); 604 } 605 606 assert(DstTy->isFloatingPointTy() && "Unknown real conversion"); 607 if (DstTy->getTypeID() < Src->getType()->getTypeID()) 608 return Builder.CreateFPTrunc(Src, DstTy, "conv"); 609 else 610 return Builder.CreateFPExt(Src, DstTy, "conv"); 611} 612 613/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 614/// type to the specified destination type, where the destination type is an 615/// LLVM scalar type. 616Value *ScalarExprEmitter:: 617EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 618 QualType SrcTy, QualType DstTy) { 619 // Get the source element type. 620 SrcTy = SrcTy->getAs<ComplexType>()->getElementType(); 621 622 // Handle conversions to bool first, they are special: comparisons against 0. 623 if (DstTy->isBooleanType()) { 624 // Complex != 0 -> (Real != 0) | (Imag != 0) 625 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 626 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 627 return Builder.CreateOr(Src.first, Src.second, "tobool"); 628 } 629 630 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 631 // the imaginary part of the complex value is discarded and the value of the 632 // real part is converted according to the conversion rules for the 633 // corresponding real type. 634 return EmitScalarConversion(Src.first, SrcTy, DstTy); 635} 636 637Value *ScalarExprEmitter::EmitNullValue(QualType Ty) { 638 if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>()) 639 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 640 641 return llvm::Constant::getNullValue(ConvertType(Ty)); 642} 643 644//===----------------------------------------------------------------------===// 645// Visitor Methods 646//===----------------------------------------------------------------------===// 647 648Value *ScalarExprEmitter::VisitExpr(Expr *E) { 649 CGF.ErrorUnsupported(E, "scalar expression"); 650 if (E->getType()->isVoidType()) 651 return 0; 652 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 653} 654 655Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 656 // Vector Mask Case 657 if (E->getNumSubExprs() == 2 || 658 (E->getNumSubExprs() == 3 && E->getExpr(2)->getType()->isVectorType())) { 659 Value *LHS = CGF.EmitScalarExpr(E->getExpr(0)); 660 Value *RHS = CGF.EmitScalarExpr(E->getExpr(1)); 661 Value *Mask; 662 663 const llvm::VectorType *LTy = cast<llvm::VectorType>(LHS->getType()); 664 unsigned LHSElts = LTy->getNumElements(); 665 666 if (E->getNumSubExprs() == 3) { 667 Mask = CGF.EmitScalarExpr(E->getExpr(2)); 668 669 // Shuffle LHS & RHS into one input vector. 670 llvm::SmallVector<llvm::Constant*, 32> concat; 671 for (unsigned i = 0; i != LHSElts; ++i) { 672 concat.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 2*i)); 673 concat.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 2*i+1)); 674 } 675 676 Value* CV = llvm::ConstantVector::get(concat.begin(), concat.size()); 677 LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat"); 678 LHSElts *= 2; 679 } else { 680 Mask = RHS; 681 } 682 683 const llvm::VectorType *MTy = cast<llvm::VectorType>(Mask->getType()); 684 llvm::Constant* EltMask; 685 686 // Treat vec3 like vec4. 687 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) 688 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 689 (1 << llvm::Log2_32(LHSElts+2))-1); 690 else if ((LHSElts == 3) && (E->getNumSubExprs() == 2)) 691 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 692 (1 << llvm::Log2_32(LHSElts+1))-1); 693 else 694 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 695 (1 << llvm::Log2_32(LHSElts))-1); 696 697 // Mask off the high bits of each shuffle index. 698 llvm::SmallVector<llvm::Constant *, 32> MaskV; 699 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) 700 MaskV.push_back(EltMask); 701 702 Value* MaskBits = llvm::ConstantVector::get(MaskV.begin(), MaskV.size()); 703 Mask = Builder.CreateAnd(Mask, MaskBits, "mask"); 704 705 // newv = undef 706 // mask = mask & maskbits 707 // for each elt 708 // n = extract mask i 709 // x = extract val n 710 // newv = insert newv, x, i 711 const llvm::VectorType *RTy = llvm::VectorType::get(LTy->getElementType(), 712 MTy->getNumElements()); 713 Value* NewV = llvm::UndefValue::get(RTy); 714 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) { 715 Value *Indx = llvm::ConstantInt::get(CGF.Int32Ty, i); 716 Indx = Builder.CreateExtractElement(Mask, Indx, "shuf_idx"); 717 Indx = Builder.CreateZExt(Indx, CGF.Int32Ty, "idx_zext"); 718 719 // Handle vec3 special since the index will be off by one for the RHS. 720 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) { 721 Value *cmpIndx, *newIndx; 722 cmpIndx = Builder.CreateICmpUGT(Indx, 723 llvm::ConstantInt::get(CGF.Int32Ty, 3), 724 "cmp_shuf_idx"); 725 newIndx = Builder.CreateSub(Indx, llvm::ConstantInt::get(CGF.Int32Ty,1), 726 "shuf_idx_adj"); 727 Indx = Builder.CreateSelect(cmpIndx, newIndx, Indx, "sel_shuf_idx"); 728 } 729 Value *VExt = Builder.CreateExtractElement(LHS, Indx, "shuf_elt"); 730 NewV = Builder.CreateInsertElement(NewV, VExt, Indx, "shuf_ins"); 731 } 732 return NewV; 733 } 734 735 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 736 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 737 738 // Handle vec3 special since the index will be off by one for the RHS. 739 llvm::SmallVector<llvm::Constant*, 32> indices; 740 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 741 llvm::Constant *C = cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i))); 742 const llvm::VectorType *VTy = cast<llvm::VectorType>(V1->getType()); 743 if (VTy->getNumElements() == 3) { 744 if (llvm::ConstantInt *CI = dyn_cast<llvm::ConstantInt>(C)) { 745 uint64_t cVal = CI->getZExtValue(); 746 if (cVal > 3) { 747 C = llvm::ConstantInt::get(C->getType(), cVal-1); 748 } 749 } 750 } 751 indices.push_back(C); 752 } 753 754 Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); 755 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 756} 757Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { 758 Expr::EvalResult Result; 759 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 760 if (E->isArrow()) 761 CGF.EmitScalarExpr(E->getBase()); 762 else 763 EmitLValue(E->getBase()); 764 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 765 } 766 767 // Emit debug info for aggregate now, if it was delayed to reduce 768 // debug info size. 769 CGDebugInfo *DI = CGF.getDebugInfo(); 770 if (DI && CGF.CGM.getCodeGenOpts().LimitDebugInfo) { 771 QualType PQTy = E->getBase()->IgnoreParenImpCasts()->getType(); 772 if (const PointerType * PTy = dyn_cast<PointerType>(PQTy)) 773 if (FieldDecl *M = dyn_cast<FieldDecl>(E->getMemberDecl())) 774 DI->getOrCreateRecordType(PTy->getPointeeType(), 775 M->getParent()->getLocation()); 776 } 777 return EmitLoadOfLValue(E); 778} 779 780Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 781 TestAndClearIgnoreResultAssign(); 782 783 // Emit subscript expressions in rvalue context's. For most cases, this just 784 // loads the lvalue formed by the subscript expr. However, we have to be 785 // careful, because the base of a vector subscript is occasionally an rvalue, 786 // so we can't get it as an lvalue. 787 if (!E->getBase()->getType()->isVectorType()) 788 return EmitLoadOfLValue(E); 789 790 // Handle the vector case. The base must be a vector, the index must be an 791 // integer value. 792 Value *Base = Visit(E->getBase()); 793 Value *Idx = Visit(E->getIdx()); 794 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerType(); 795 Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vecidxcast"); 796 return Builder.CreateExtractElement(Base, Idx, "vecext"); 797} 798 799static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, 800 unsigned Off, const llvm::Type *I32Ty) { 801 int MV = SVI->getMaskValue(Idx); 802 if (MV == -1) 803 return llvm::UndefValue::get(I32Ty); 804 return llvm::ConstantInt::get(I32Ty, Off+MV); 805} 806 807Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) { 808 bool Ignore = TestAndClearIgnoreResultAssign(); 809 (void)Ignore; 810 assert (Ignore == false && "init list ignored"); 811 unsigned NumInitElements = E->getNumInits(); 812 813 if (E->hadArrayRangeDesignator()) 814 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 815 816 const llvm::VectorType *VType = 817 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 818 819 // We have a scalar in braces. Just use the first element. 820 if (!VType) 821 return Visit(E->getInit(0)); 822 823 unsigned ResElts = VType->getNumElements(); 824 825 // Loop over initializers collecting the Value for each, and remembering 826 // whether the source was swizzle (ExtVectorElementExpr). This will allow 827 // us to fold the shuffle for the swizzle into the shuffle for the vector 828 // initializer, since LLVM optimizers generally do not want to touch 829 // shuffles. 830 unsigned CurIdx = 0; 831 bool VIsUndefShuffle = false; 832 llvm::Value *V = llvm::UndefValue::get(VType); 833 for (unsigned i = 0; i != NumInitElements; ++i) { 834 Expr *IE = E->getInit(i); 835 Value *Init = Visit(IE); 836 llvm::SmallVector<llvm::Constant*, 16> Args; 837 838 const llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType()); 839 840 // Handle scalar elements. If the scalar initializer is actually one 841 // element of a different vector of the same width, use shuffle instead of 842 // extract+insert. 843 if (!VVT) { 844 if (isa<ExtVectorElementExpr>(IE)) { 845 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init); 846 847 if (EI->getVectorOperandType()->getNumElements() == ResElts) { 848 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand()); 849 Value *LHS = 0, *RHS = 0; 850 if (CurIdx == 0) { 851 // insert into undef -> shuffle (src, undef) 852 Args.push_back(C); 853 for (unsigned j = 1; j != ResElts; ++j) 854 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 855 856 LHS = EI->getVectorOperand(); 857 RHS = V; 858 VIsUndefShuffle = true; 859 } else if (VIsUndefShuffle) { 860 // insert into undefshuffle && size match -> shuffle (v, src) 861 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V); 862 for (unsigned j = 0; j != CurIdx; ++j) 863 Args.push_back(getMaskElt(SVV, j, 0, CGF.Int32Ty)); 864 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, 865 ResElts + C->getZExtValue())); 866 for (unsigned j = CurIdx + 1; j != ResElts; ++j) 867 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 868 869 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 870 RHS = EI->getVectorOperand(); 871 VIsUndefShuffle = false; 872 } 873 if (!Args.empty()) { 874 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 875 V = Builder.CreateShuffleVector(LHS, RHS, Mask); 876 ++CurIdx; 877 continue; 878 } 879 } 880 } 881 Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, CurIdx); 882 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 883 VIsUndefShuffle = false; 884 ++CurIdx; 885 continue; 886 } 887 888 unsigned InitElts = VVT->getNumElements(); 889 890 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's 891 // input is the same width as the vector being constructed, generate an 892 // optimized shuffle of the swizzle input into the result. 893 unsigned Offset = (CurIdx == 0) ? 0 : ResElts; 894 if (isa<ExtVectorElementExpr>(IE)) { 895 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init); 896 Value *SVOp = SVI->getOperand(0); 897 const llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType()); 898 899 if (OpTy->getNumElements() == ResElts) { 900 for (unsigned j = 0; j != CurIdx; ++j) { 901 // If the current vector initializer is a shuffle with undef, merge 902 // this shuffle directly into it. 903 if (VIsUndefShuffle) { 904 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0, 905 CGF.Int32Ty)); 906 } else { 907 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); 908 } 909 } 910 for (unsigned j = 0, je = InitElts; j != je; ++j) 911 Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty)); 912 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 913 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 914 915 if (VIsUndefShuffle) 916 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 917 918 Init = SVOp; 919 } 920 } 921 922 // Extend init to result vector length, and then shuffle its contribution 923 // to the vector initializer into V. 924 if (Args.empty()) { 925 for (unsigned j = 0; j != InitElts; ++j) 926 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); 927 for (unsigned j = InitElts; j != ResElts; ++j) 928 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 929 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 930 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), 931 Mask, "vext"); 932 933 Args.clear(); 934 for (unsigned j = 0; j != CurIdx; ++j) 935 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j)); 936 for (unsigned j = 0; j != InitElts; ++j) 937 Args.push_back(llvm::ConstantInt::get(CGF.Int32Ty, j+Offset)); 938 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 939 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 940 } 941 942 // If V is undef, make sure it ends up on the RHS of the shuffle to aid 943 // merging subsequent shuffles into this one. 944 if (CurIdx == 0) 945 std::swap(V, Init); 946 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], ResElts); 947 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); 948 VIsUndefShuffle = isa<llvm::UndefValue>(Init); 949 CurIdx += InitElts; 950 } 951 952 // FIXME: evaluate codegen vs. shuffling against constant null vector. 953 // Emit remaining default initializers. 954 const llvm::Type *EltTy = VType->getElementType(); 955 956 // Emit remaining default initializers 957 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { 958 Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, CurIdx); 959 llvm::Value *Init = llvm::Constant::getNullValue(EltTy); 960 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 961 } 962 return V; 963} 964 965static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { 966 const Expr *E = CE->getSubExpr(); 967 968 if (CE->getCastKind() == CK_UncheckedDerivedToBase) 969 return false; 970 971 if (isa<CXXThisExpr>(E)) { 972 // We always assume that 'this' is never null. 973 return false; 974 } 975 976 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { 977 // And that glvalue casts are never null. 978 if (ICE->getValueKind() != VK_RValue) 979 return false; 980 } 981 982 return true; 983} 984 985// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 986// have to handle a more broad range of conversions than explicit casts, as they 987// handle things like function to ptr-to-function decay etc. 988Value *ScalarExprEmitter::EmitCastExpr(CastExpr *CE) { 989 Expr *E = CE->getSubExpr(); 990 QualType DestTy = CE->getType(); 991 CastKind Kind = CE->getCastKind(); 992 993 if (!DestTy->isVoidType()) 994 TestAndClearIgnoreResultAssign(); 995 996 // Since almost all cast kinds apply to scalars, this switch doesn't have 997 // a default case, so the compiler will warn on a missing case. The cases 998 // are in the same order as in the CastKind enum. 999 switch (Kind) { 1000 case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!"); 1001 1002 case CK_LValueBitCast: 1003 case CK_ObjCObjectLValueCast: { 1004 Value *V = EmitLValue(E).getAddress(); 1005 V = Builder.CreateBitCast(V, 1006 ConvertType(CGF.getContext().getPointerType(DestTy))); 1007 return EmitLoadOfLValue(CGF.MakeAddrLValue(V, DestTy), DestTy); 1008 } 1009 1010 case CK_AnyPointerToObjCPointerCast: 1011 case CK_AnyPointerToBlockPointerCast: 1012 case CK_BitCast: { 1013 Value *Src = Visit(const_cast<Expr*>(E)); 1014 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 1015 } 1016 case CK_NoOp: 1017 case CK_UserDefinedConversion: 1018 return Visit(const_cast<Expr*>(E)); 1019 1020 case CK_BaseToDerived: { 1021 const CXXRecordDecl *DerivedClassDecl = 1022 DestTy->getCXXRecordDeclForPointerType(); 1023 1024 return CGF.GetAddressOfDerivedClass(Visit(E), DerivedClassDecl, 1025 CE->path_begin(), CE->path_end(), 1026 ShouldNullCheckClassCastValue(CE)); 1027 } 1028 case CK_UncheckedDerivedToBase: 1029 case CK_DerivedToBase: { 1030 const RecordType *DerivedClassTy = 1031 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 1032 CXXRecordDecl *DerivedClassDecl = 1033 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 1034 1035 return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl, 1036 CE->path_begin(), CE->path_end(), 1037 ShouldNullCheckClassCastValue(CE)); 1038 } 1039 case CK_Dynamic: { 1040 Value *V = Visit(const_cast<Expr*>(E)); 1041 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 1042 return CGF.EmitDynamicCast(V, DCE); 1043 } 1044 1045 case CK_ArrayToPointerDecay: { 1046 assert(E->getType()->isArrayType() && 1047 "Array to pointer decay must have array source type!"); 1048 1049 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 1050 1051 // Note that VLA pointers are always decayed, so we don't need to do 1052 // anything here. 1053 if (!E->getType()->isVariableArrayType()) { 1054 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 1055 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 1056 ->getElementType()) && 1057 "Expected pointer to array"); 1058 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 1059 } 1060 1061 return V; 1062 } 1063 case CK_FunctionToPointerDecay: 1064 return EmitLValue(E).getAddress(); 1065 1066 case CK_NullToPointer: 1067 if (MustVisitNullValue(E)) 1068 (void) Visit(E); 1069 1070 return llvm::ConstantPointerNull::get( 1071 cast<llvm::PointerType>(ConvertType(DestTy))); 1072 1073 case CK_NullToMemberPointer: { 1074 if (MustVisitNullValue(E)) 1075 (void) Visit(E); 1076 1077 const MemberPointerType *MPT = CE->getType()->getAs<MemberPointerType>(); 1078 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 1079 } 1080 1081 case CK_BaseToDerivedMemberPointer: 1082 case CK_DerivedToBaseMemberPointer: { 1083 Value *Src = Visit(E); 1084 1085 // Note that the AST doesn't distinguish between checked and 1086 // unchecked member pointer conversions, so we always have to 1087 // implement checked conversions here. This is inefficient when 1088 // actual control flow may be required in order to perform the 1089 // check, which it is for data member pointers (but not member 1090 // function pointers on Itanium and ARM). 1091 return CGF.CGM.getCXXABI().EmitMemberPointerConversion(CGF, CE, Src); 1092 } 1093 1094 case CK_FloatingRealToComplex: 1095 case CK_FloatingComplexCast: 1096 case CK_IntegralRealToComplex: 1097 case CK_IntegralComplexCast: 1098 case CK_IntegralComplexToFloatingComplex: 1099 case CK_FloatingComplexToIntegralComplex: 1100 case CK_ConstructorConversion: 1101 case CK_ToUnion: 1102 llvm_unreachable("scalar cast to non-scalar value"); 1103 break; 1104 1105 case CK_IntegralToPointer: { 1106 Value *Src = Visit(const_cast<Expr*>(E)); 1107 1108 // First, convert to the correct width so that we control the kind of 1109 // extension. 1110 const llvm::Type *MiddleTy = CGF.IntPtrTy; 1111 bool InputSigned = E->getType()->isSignedIntegerType(); 1112 llvm::Value* IntResult = 1113 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 1114 1115 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 1116 } 1117 case CK_PointerToIntegral: { 1118 Value *Src = Visit(const_cast<Expr*>(E)); 1119 1120 // Handle conversion to bool correctly. 1121 if (DestTy->isBooleanType()) 1122 return EmitScalarConversion(Src, E->getType(), DestTy); 1123 1124 return Builder.CreatePtrToInt(Src, ConvertType(DestTy)); 1125 } 1126 case CK_ToVoid: { 1127 if (E->Classify(CGF.getContext()).isGLValue()) { 1128 LValue LV = CGF.EmitLValue(E); 1129 if (LV.isPropertyRef()) 1130 CGF.EmitLoadOfPropertyRefLValue(LV, E->getType()); 1131 else if (LV.isKVCRef()) 1132 CGF.EmitLoadOfKVCRefLValue(LV, E->getType()); 1133 } 1134 else 1135 CGF.EmitAnyExpr(E, AggValueSlot::ignored(), true); 1136 return 0; 1137 } 1138 case CK_VectorSplat: { 1139 const llvm::Type *DstTy = ConvertType(DestTy); 1140 Value *Elt = Visit(const_cast<Expr*>(E)); 1141 1142 // Insert the element in element zero of an undef vector 1143 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 1144 llvm::Value *Idx = llvm::ConstantInt::get(CGF.Int32Ty, 0); 1145 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 1146 1147 // Splat the element across to all elements 1148 llvm::SmallVector<llvm::Constant*, 16> Args; 1149 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 1150 llvm::Constant *Zero = llvm::ConstantInt::get(CGF.Int32Ty, 0); 1151 for (unsigned i = 0; i < NumElements; i++) 1152 Args.push_back(Zero); 1153 1154 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 1155 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 1156 return Yay; 1157 } 1158 1159 case CK_IntegralCast: 1160 case CK_IntegralToFloating: 1161 case CK_FloatingToIntegral: 1162 case CK_FloatingCast: 1163 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 1164 1165 case CK_IntegralToBoolean: 1166 return EmitIntToBoolConversion(Visit(E)); 1167 case CK_PointerToBoolean: 1168 return EmitPointerToBoolConversion(Visit(E)); 1169 case CK_FloatingToBoolean: 1170 return EmitFloatToBoolConversion(Visit(E)); 1171 case CK_MemberPointerToBoolean: { 1172 llvm::Value *MemPtr = Visit(E); 1173 const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>(); 1174 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT); 1175 } 1176 1177 case CK_FloatingComplexToReal: 1178 case CK_IntegralComplexToReal: 1179 return CGF.EmitComplexExpr(E, false, true).first; 1180 1181 case CK_FloatingComplexToBoolean: 1182 case CK_IntegralComplexToBoolean: { 1183 CodeGenFunction::ComplexPairTy V = CGF.EmitComplexExpr(E); 1184 1185 // TODO: kill this function off, inline appropriate case here 1186 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 1187 } 1188 1189 } 1190 1191 llvm_unreachable("unknown scalar cast"); 1192 return 0; 1193} 1194 1195Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 1196 return CGF.EmitCompoundStmt(*E->getSubStmt(), 1197 !E->getType()->isVoidType()).getScalarVal(); 1198} 1199 1200Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 1201 llvm::Value *V = CGF.GetAddrOfBlockDecl(E); 1202 if (E->getType().isObjCGCWeak()) 1203 return CGF.CGM.getObjCRuntime().EmitObjCWeakRead(CGF, V); 1204 return CGF.EmitLoadOfScalar(V, false, 0, E->getType()); 1205} 1206 1207//===----------------------------------------------------------------------===// 1208// Unary Operators 1209//===----------------------------------------------------------------------===// 1210 1211llvm::Value *ScalarExprEmitter:: 1212EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 1213 bool isInc, bool isPre) { 1214 1215 QualType ValTy = E->getSubExpr()->getType(); 1216 llvm::Value *InVal = EmitLoadOfLValue(LV, ValTy); 1217 1218 int AmountVal = isInc ? 1 : -1; 1219 1220 if (ValTy->isPointerType() && 1221 ValTy->getAs<PointerType>()->isVariableArrayType()) { 1222 // The amount of the addition/subtraction needs to account for the VLA size 1223 CGF.ErrorUnsupported(E, "VLA pointer inc/dec"); 1224 } 1225 1226 llvm::Value *NextVal; 1227 if (const llvm::PointerType *PT = 1228 dyn_cast<llvm::PointerType>(InVal->getType())) { 1229 llvm::Constant *Inc = llvm::ConstantInt::get(CGF.Int32Ty, AmountVal); 1230 if (!isa<llvm::FunctionType>(PT->getElementType())) { 1231 QualType PTEE = ValTy->getPointeeType(); 1232 if (const ObjCObjectType *OIT = PTEE->getAs<ObjCObjectType>()) { 1233 // Handle interface types, which are not represented with a concrete 1234 // type. 1235 int size = CGF.getContext().getTypeSize(OIT) / 8; 1236 if (!isInc) 1237 size = -size; 1238 Inc = llvm::ConstantInt::get(Inc->getType(), size); 1239 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1240 InVal = Builder.CreateBitCast(InVal, i8Ty); 1241 NextVal = Builder.CreateGEP(InVal, Inc, "add.ptr"); 1242 llvm::Value *lhs = LV.getAddress(); 1243 lhs = Builder.CreateBitCast(lhs, llvm::PointerType::getUnqual(i8Ty)); 1244 LV = CGF.MakeAddrLValue(lhs, ValTy); 1245 } else 1246 NextVal = Builder.CreateInBoundsGEP(InVal, Inc, "ptrincdec"); 1247 } else { 1248 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1249 NextVal = Builder.CreateBitCast(InVal, i8Ty, "tmp"); 1250 NextVal = Builder.CreateGEP(NextVal, Inc, "ptrincdec"); 1251 NextVal = Builder.CreateBitCast(NextVal, InVal->getType()); 1252 } 1253 } else if (InVal->getType()->isIntegerTy(1) && isInc) { 1254 // Bool++ is an interesting case, due to promotion rules, we get: 1255 // Bool++ -> Bool = Bool+1 -> Bool = (int)Bool+1 -> 1256 // Bool = ((int)Bool+1) != 0 1257 // An interesting aspect of this is that increment is always true. 1258 // Decrement does not have this property. 1259 NextVal = llvm::ConstantInt::getTrue(VMContext); 1260 } else if (isa<llvm::IntegerType>(InVal->getType())) { 1261 NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); 1262 1263 if (!ValTy->isSignedIntegerType()) 1264 // Unsigned integer inc is always two's complement. 1265 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1266 else { 1267 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1268 case LangOptions::SOB_Undefined: 1269 NextVal = Builder.CreateNSWAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1270 break; 1271 case LangOptions::SOB_Defined: 1272 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1273 break; 1274 case LangOptions::SOB_Trapping: 1275 BinOpInfo BinOp; 1276 BinOp.LHS = InVal; 1277 BinOp.RHS = NextVal; 1278 BinOp.Ty = E->getType(); 1279 BinOp.Opcode = BO_Add; 1280 BinOp.E = E; 1281 NextVal = EmitOverflowCheckedBinOp(BinOp); 1282 break; 1283 } 1284 } 1285 } else { 1286 // Add the inc/dec to the real part. 1287 if (InVal->getType()->isFloatTy()) 1288 NextVal = 1289 llvm::ConstantFP::get(VMContext, 1290 llvm::APFloat(static_cast<float>(AmountVal))); 1291 else if (InVal->getType()->isDoubleTy()) 1292 NextVal = 1293 llvm::ConstantFP::get(VMContext, 1294 llvm::APFloat(static_cast<double>(AmountVal))); 1295 else { 1296 llvm::APFloat F(static_cast<float>(AmountVal)); 1297 bool ignored; 1298 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, 1299 &ignored); 1300 NextVal = llvm::ConstantFP::get(VMContext, F); 1301 } 1302 NextVal = Builder.CreateFAdd(InVal, NextVal, isInc ? "inc" : "dec"); 1303 } 1304 1305 // Store the updated result through the lvalue. 1306 if (LV.isBitField()) 1307 CGF.EmitStoreThroughBitfieldLValue(RValue::get(NextVal), LV, ValTy, &NextVal); 1308 else 1309 CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV, ValTy); 1310 1311 // If this is a postinc, return the value read from memory, otherwise use the 1312 // updated value. 1313 return isPre ? NextVal : InVal; 1314} 1315 1316 1317 1318Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1319 TestAndClearIgnoreResultAssign(); 1320 // Emit unary minus with EmitSub so we handle overflow cases etc. 1321 BinOpInfo BinOp; 1322 BinOp.RHS = Visit(E->getSubExpr()); 1323 1324 if (BinOp.RHS->getType()->isFPOrFPVectorTy()) 1325 BinOp.LHS = llvm::ConstantFP::getZeroValueForNegation(BinOp.RHS->getType()); 1326 else 1327 BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType()); 1328 BinOp.Ty = E->getType(); 1329 BinOp.Opcode = BO_Sub; 1330 BinOp.E = E; 1331 return EmitSub(BinOp); 1332} 1333 1334Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1335 TestAndClearIgnoreResultAssign(); 1336 Value *Op = Visit(E->getSubExpr()); 1337 return Builder.CreateNot(Op, "neg"); 1338} 1339 1340Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1341 // Compare operand to zero. 1342 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1343 1344 // Invert value. 1345 // TODO: Could dynamically modify easy computations here. For example, if 1346 // the operand is an icmp ne, turn into icmp eq. 1347 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1348 1349 // ZExt result to the expr type. 1350 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1351} 1352 1353Value *ScalarExprEmitter::VisitOffsetOfExpr(OffsetOfExpr *E) { 1354 // Try folding the offsetof to a constant. 1355 Expr::EvalResult EvalResult; 1356 if (E->Evaluate(EvalResult, CGF.getContext())) 1357 return llvm::ConstantInt::get(VMContext, EvalResult.Val.getInt()); 1358 1359 // Loop over the components of the offsetof to compute the value. 1360 unsigned n = E->getNumComponents(); 1361 const llvm::Type* ResultType = ConvertType(E->getType()); 1362 llvm::Value* Result = llvm::Constant::getNullValue(ResultType); 1363 QualType CurrentType = E->getTypeSourceInfo()->getType(); 1364 for (unsigned i = 0; i != n; ++i) { 1365 OffsetOfExpr::OffsetOfNode ON = E->getComponent(i); 1366 llvm::Value *Offset = 0; 1367 switch (ON.getKind()) { 1368 case OffsetOfExpr::OffsetOfNode::Array: { 1369 // Compute the index 1370 Expr *IdxExpr = E->getIndexExpr(ON.getArrayExprIndex()); 1371 llvm::Value* Idx = CGF.EmitScalarExpr(IdxExpr); 1372 bool IdxSigned = IdxExpr->getType()->isSignedIntegerType(); 1373 Idx = Builder.CreateIntCast(Idx, ResultType, IdxSigned, "conv"); 1374 1375 // Save the element type 1376 CurrentType = 1377 CGF.getContext().getAsArrayType(CurrentType)->getElementType(); 1378 1379 // Compute the element size 1380 llvm::Value* ElemSize = llvm::ConstantInt::get(ResultType, 1381 CGF.getContext().getTypeSizeInChars(CurrentType).getQuantity()); 1382 1383 // Multiply out to compute the result 1384 Offset = Builder.CreateMul(Idx, ElemSize); 1385 break; 1386 } 1387 1388 case OffsetOfExpr::OffsetOfNode::Field: { 1389 FieldDecl *MemberDecl = ON.getField(); 1390 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1391 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1392 1393 // Compute the index of the field in its parent. 1394 unsigned i = 0; 1395 // FIXME: It would be nice if we didn't have to loop here! 1396 for (RecordDecl::field_iterator Field = RD->field_begin(), 1397 FieldEnd = RD->field_end(); 1398 Field != FieldEnd; (void)++Field, ++i) { 1399 if (*Field == MemberDecl) 1400 break; 1401 } 1402 assert(i < RL.getFieldCount() && "offsetof field in wrong type"); 1403 1404 // Compute the offset to the field 1405 int64_t OffsetInt = RL.getFieldOffset(i) / 1406 CGF.getContext().getCharWidth(); 1407 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1408 1409 // Save the element type. 1410 CurrentType = MemberDecl->getType(); 1411 break; 1412 } 1413 1414 case OffsetOfExpr::OffsetOfNode::Identifier: 1415 llvm_unreachable("dependent __builtin_offsetof"); 1416 1417 case OffsetOfExpr::OffsetOfNode::Base: { 1418 if (ON.getBase()->isVirtual()) { 1419 CGF.ErrorUnsupported(E, "virtual base in offsetof"); 1420 continue; 1421 } 1422 1423 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1424 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1425 1426 // Save the element type. 1427 CurrentType = ON.getBase()->getType(); 1428 1429 // Compute the offset to the base. 1430 const RecordType *BaseRT = CurrentType->getAs<RecordType>(); 1431 CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl()); 1432 int64_t OffsetInt = RL.getBaseClassOffsetInBits(BaseRD) / 1433 CGF.getContext().getCharWidth(); 1434 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1435 break; 1436 } 1437 } 1438 Result = Builder.CreateAdd(Result, Offset); 1439 } 1440 return Result; 1441} 1442 1443/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of 1444/// argument of the sizeof expression as an integer. 1445Value * 1446ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { 1447 QualType TypeToSize = E->getTypeOfArgument(); 1448 if (E->isSizeOf()) { 1449 if (const VariableArrayType *VAT = 1450 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1451 if (E->isArgumentType()) { 1452 // sizeof(type) - make sure to emit the VLA size. 1453 CGF.EmitVLASize(TypeToSize); 1454 } else { 1455 // C99 6.5.3.4p2: If the argument is an expression of type 1456 // VLA, it is evaluated. 1457 CGF.EmitAnyExpr(E->getArgumentExpr()); 1458 } 1459 1460 return CGF.GetVLASize(VAT); 1461 } 1462 } 1463 1464 // If this isn't sizeof(vla), the result must be constant; use the constant 1465 // folding logic so we don't have to duplicate it here. 1466 Expr::EvalResult Result; 1467 E->Evaluate(Result, CGF.getContext()); 1468 return llvm::ConstantInt::get(VMContext, Result.Val.getInt()); 1469} 1470 1471Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1472 Expr *Op = E->getSubExpr(); 1473 if (Op->getType()->isAnyComplexType()) { 1474 // If it's an l-value, load through the appropriate subobject l-value. 1475 // Note that we have to ask E because Op might be an l-value that 1476 // this won't work for, e.g. an Obj-C property. 1477 if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) 1478 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E), E->getType()) 1479 .getScalarVal(); 1480 1481 // Otherwise, calculate and project. 1482 return CGF.EmitComplexExpr(Op, false, true).first; 1483 } 1484 1485 return Visit(Op); 1486} 1487 1488Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1489 Expr *Op = E->getSubExpr(); 1490 if (Op->getType()->isAnyComplexType()) { 1491 // If it's an l-value, load through the appropriate subobject l-value. 1492 // Note that we have to ask E because Op might be an l-value that 1493 // this won't work for, e.g. an Obj-C property. 1494 if (Op->isLvalue(CGF.getContext()) == Expr::LV_Valid) 1495 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E), E->getType()) 1496 .getScalarVal(); 1497 1498 // Otherwise, calculate and project. 1499 return CGF.EmitComplexExpr(Op, true, false).second; 1500 } 1501 1502 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1503 // effects are evaluated, but not the actual value. 1504 CGF.EmitScalarExpr(Op, true); 1505 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1506} 1507 1508//===----------------------------------------------------------------------===// 1509// Binary Operators 1510//===----------------------------------------------------------------------===// 1511 1512BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1513 TestAndClearIgnoreResultAssign(); 1514 BinOpInfo Result; 1515 Result.LHS = Visit(E->getLHS()); 1516 Result.RHS = Visit(E->getRHS()); 1517 Result.Ty = E->getType(); 1518 Result.Opcode = E->getOpcode(); 1519 Result.E = E; 1520 return Result; 1521} 1522 1523LValue ScalarExprEmitter::EmitCompoundAssignLValue( 1524 const CompoundAssignOperator *E, 1525 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &), 1526 Value *&Result) { 1527 QualType LHSTy = E->getLHS()->getType(); 1528 BinOpInfo OpInfo; 1529 1530 if (E->getComputationResultType()->isAnyComplexType()) { 1531 // This needs to go through the complex expression emitter, but it's a tad 1532 // complicated to do that... I'm leaving it out for now. (Note that we do 1533 // actually need the imaginary part of the RHS for multiplication and 1534 // division.) 1535 CGF.ErrorUnsupported(E, "complex compound assignment"); 1536 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType())); 1537 return LValue(); 1538 } 1539 1540 // Emit the RHS first. __block variables need to have the rhs evaluated 1541 // first, plus this should improve codegen a little. 1542 OpInfo.RHS = Visit(E->getRHS()); 1543 OpInfo.Ty = E->getComputationResultType(); 1544 OpInfo.Opcode = E->getOpcode(); 1545 OpInfo.E = E; 1546 // Load/convert the LHS. 1547 LValue LHSLV = EmitCheckedLValue(E->getLHS()); 1548 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 1549 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 1550 E->getComputationLHSType()); 1551 1552 // Expand the binary operator. 1553 Result = (this->*Func)(OpInfo); 1554 1555 // Convert the result back to the LHS type. 1556 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 1557 1558 // Store the result value into the LHS lvalue. Bit-fields are handled 1559 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 1560 // 'An assignment expression has the value of the left operand after the 1561 // assignment...'. 1562 if (LHSLV.isBitField()) 1563 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, 1564 &Result); 1565 else 1566 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); 1567 1568 return LHSLV; 1569} 1570 1571Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 1572 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 1573 bool Ignore = TestAndClearIgnoreResultAssign(); 1574 Value *RHS; 1575 LValue LHS = EmitCompoundAssignLValue(E, Func, RHS); 1576 1577 // If the result is clearly ignored, return now. 1578 if (Ignore) 1579 return 0; 1580 1581 // The result of an assignment in C is the assigned r-value. 1582 if (!CGF.getContext().getLangOptions().CPlusPlus) 1583 return RHS; 1584 1585 // Objective-C property assignment never reloads the value following a store. 1586 if (LHS.isPropertyRef() || LHS.isKVCRef()) 1587 return RHS; 1588 1589 // If the lvalue is non-volatile, return the computed value of the assignment. 1590 if (!LHS.isVolatileQualified()) 1591 return RHS; 1592 1593 // Otherwise, reload the value. 1594 return EmitLoadOfLValue(LHS, E->getType()); 1595} 1596 1597void ScalarExprEmitter::EmitUndefinedBehaviorIntegerDivAndRemCheck( 1598 const BinOpInfo &Ops, 1599 llvm::Value *Zero, bool isDiv) { 1600 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); 1601 llvm::BasicBlock *contBB = 1602 CGF.createBasicBlock(isDiv ? "div.cont" : "rem.cont", CGF.CurFn); 1603 1604 const llvm::IntegerType *Ty = cast<llvm::IntegerType>(Zero->getType()); 1605 1606 if (Ops.Ty->hasSignedIntegerRepresentation()) { 1607 llvm::Value *IntMin = 1608 llvm::ConstantInt::get(VMContext, 1609 llvm::APInt::getSignedMinValue(Ty->getBitWidth())); 1610 llvm::Value *NegOne = llvm::ConstantInt::get(Ty, -1ULL); 1611 1612 llvm::Value *Cond1 = Builder.CreateICmpEQ(Ops.RHS, Zero); 1613 llvm::Value *LHSCmp = Builder.CreateICmpEQ(Ops.LHS, IntMin); 1614 llvm::Value *RHSCmp = Builder.CreateICmpEQ(Ops.RHS, NegOne); 1615 llvm::Value *Cond2 = Builder.CreateAnd(LHSCmp, RHSCmp, "and"); 1616 Builder.CreateCondBr(Builder.CreateOr(Cond1, Cond2, "or"), 1617 overflowBB, contBB); 1618 } else { 1619 CGF.Builder.CreateCondBr(Builder.CreateICmpEQ(Ops.RHS, Zero), 1620 overflowBB, contBB); 1621 } 1622 EmitOverflowBB(overflowBB); 1623 Builder.SetInsertPoint(contBB); 1624} 1625 1626Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 1627 if (isTrapvOverflowBehavior()) { 1628 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 1629 1630 if (Ops.Ty->isIntegerType()) 1631 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, true); 1632 else if (Ops.Ty->isRealFloatingType()) { 1633 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", 1634 CGF.CurFn); 1635 llvm::BasicBlock *DivCont = CGF.createBasicBlock("div.cont", CGF.CurFn); 1636 CGF.Builder.CreateCondBr(Builder.CreateFCmpOEQ(Ops.RHS, Zero), 1637 overflowBB, DivCont); 1638 EmitOverflowBB(overflowBB); 1639 Builder.SetInsertPoint(DivCont); 1640 } 1641 } 1642 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1643 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 1644 else if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1645 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 1646 else 1647 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 1648} 1649 1650Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 1651 // Rem in C can't be a floating point type: C99 6.5.5p2. 1652 if (isTrapvOverflowBehavior()) { 1653 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 1654 1655 if (Ops.Ty->isIntegerType()) 1656 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, false); 1657 } 1658 1659 if (Ops.Ty->isUnsignedIntegerType()) 1660 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 1661 else 1662 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 1663} 1664 1665Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 1666 unsigned IID; 1667 unsigned OpID = 0; 1668 1669 switch (Ops.Opcode) { 1670 case BO_Add: 1671 case BO_AddAssign: 1672 OpID = 1; 1673 IID = llvm::Intrinsic::sadd_with_overflow; 1674 break; 1675 case BO_Sub: 1676 case BO_SubAssign: 1677 OpID = 2; 1678 IID = llvm::Intrinsic::ssub_with_overflow; 1679 break; 1680 case BO_Mul: 1681 case BO_MulAssign: 1682 OpID = 3; 1683 IID = llvm::Intrinsic::smul_with_overflow; 1684 break; 1685 default: 1686 assert(false && "Unsupported operation for overflow detection"); 1687 IID = 0; 1688 } 1689 OpID <<= 1; 1690 OpID |= 1; 1691 1692 const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1693 1694 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1); 1695 1696 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1697 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1698 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1699 1700 // Branch in case of overflow. 1701 llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); 1702 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); 1703 llvm::BasicBlock *continueBB = CGF.createBasicBlock("nooverflow", CGF.CurFn); 1704 1705 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1706 1707 // Handle overflow with llvm.trap. 1708 const std::string *handlerName = 1709 &CGF.getContext().getLangOptions().OverflowHandler; 1710 if (handlerName->empty()) { 1711 EmitOverflowBB(overflowBB); 1712 Builder.SetInsertPoint(continueBB); 1713 return result; 1714 } 1715 1716 // If an overflow handler is set, then we want to call it and then use its 1717 // result, if it returns. 1718 Builder.SetInsertPoint(overflowBB); 1719 1720 // Get the overflow handler. 1721 const llvm::Type *Int8Ty = llvm::Type::getInt8Ty(VMContext); 1722 std::vector<const llvm::Type*> argTypes; 1723 argTypes.push_back(CGF.Int64Ty); argTypes.push_back(CGF.Int64Ty); 1724 argTypes.push_back(Int8Ty); argTypes.push_back(Int8Ty); 1725 llvm::FunctionType *handlerTy = 1726 llvm::FunctionType::get(CGF.Int64Ty, argTypes, true); 1727 llvm::Value *handler = CGF.CGM.CreateRuntimeFunction(handlerTy, *handlerName); 1728 1729 // Sign extend the args to 64-bit, so that we can use the same handler for 1730 // all types of overflow. 1731 llvm::Value *lhs = Builder.CreateSExt(Ops.LHS, CGF.Int64Ty); 1732 llvm::Value *rhs = Builder.CreateSExt(Ops.RHS, CGF.Int64Ty); 1733 1734 // Call the handler with the two arguments, the operation, and the size of 1735 // the result. 1736 llvm::Value *handlerResult = Builder.CreateCall4(handler, lhs, rhs, 1737 Builder.getInt8(OpID), 1738 Builder.getInt8(cast<llvm::IntegerType>(opTy)->getBitWidth())); 1739 1740 // Truncate the result back to the desired size. 1741 handlerResult = Builder.CreateTrunc(handlerResult, opTy); 1742 Builder.CreateBr(continueBB); 1743 1744 Builder.SetInsertPoint(continueBB); 1745 llvm::PHINode *phi = Builder.CreatePHI(opTy); 1746 phi->reserveOperandSpace(2); 1747 phi->addIncoming(result, initialBB); 1748 phi->addIncoming(handlerResult, overflowBB); 1749 1750 return phi; 1751} 1752 1753Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 1754 if (!Ops.Ty->isAnyPointerType()) { 1755 if (Ops.Ty->hasSignedIntegerRepresentation()) { 1756 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1757 case LangOptions::SOB_Undefined: 1758 return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add"); 1759 case LangOptions::SOB_Defined: 1760 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1761 case LangOptions::SOB_Trapping: 1762 return EmitOverflowCheckedBinOp(Ops); 1763 } 1764 } 1765 1766 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1767 return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add"); 1768 1769 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 1770 } 1771 1772 // Must have binary (not unary) expr here. Unary pointer decrement doesn't 1773 // use this path. 1774 const BinaryOperator *BinOp = cast<BinaryOperator>(Ops.E); 1775 1776 if (Ops.Ty->isPointerType() && 1777 Ops.Ty->getAs<PointerType>()->isVariableArrayType()) { 1778 // The amount of the addition needs to account for the VLA size 1779 CGF.ErrorUnsupported(BinOp, "VLA pointer addition"); 1780 } 1781 1782 Value *Ptr, *Idx; 1783 Expr *IdxExp; 1784 const PointerType *PT = BinOp->getLHS()->getType()->getAs<PointerType>(); 1785 const ObjCObjectPointerType *OPT = 1786 BinOp->getLHS()->getType()->getAs<ObjCObjectPointerType>(); 1787 if (PT || OPT) { 1788 Ptr = Ops.LHS; 1789 Idx = Ops.RHS; 1790 IdxExp = BinOp->getRHS(); 1791 } else { // int + pointer 1792 PT = BinOp->getRHS()->getType()->getAs<PointerType>(); 1793 OPT = BinOp->getRHS()->getType()->getAs<ObjCObjectPointerType>(); 1794 assert((PT || OPT) && "Invalid add expr"); 1795 Ptr = Ops.RHS; 1796 Idx = Ops.LHS; 1797 IdxExp = BinOp->getLHS(); 1798 } 1799 1800 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1801 if (Width < CGF.LLVMPointerWidth) { 1802 // Zero or sign extend the pointer value based on whether the index is 1803 // signed or not. 1804 const llvm::Type *IdxType = CGF.IntPtrTy; 1805 if (IdxExp->getType()->isSignedIntegerType()) 1806 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1807 else 1808 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1809 } 1810 const QualType ElementType = PT ? PT->getPointeeType() : OPT->getPointeeType(); 1811 // Handle interface types, which are not represented with a concrete type. 1812 if (const ObjCObjectType *OIT = ElementType->getAs<ObjCObjectType>()) { 1813 llvm::Value *InterfaceSize = 1814 llvm::ConstantInt::get(Idx->getType(), 1815 CGF.getContext().getTypeSizeInChars(OIT).getQuantity()); 1816 Idx = Builder.CreateMul(Idx, InterfaceSize); 1817 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1818 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1819 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1820 return Builder.CreateBitCast(Res, Ptr->getType()); 1821 } 1822 1823 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 1824 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 1825 // future proof. 1826 if (ElementType->isVoidType() || ElementType->isFunctionType()) { 1827 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1828 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 1829 Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); 1830 return Builder.CreateBitCast(Res, Ptr->getType()); 1831 } 1832 1833 return Builder.CreateInBoundsGEP(Ptr, Idx, "add.ptr"); 1834} 1835 1836Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 1837 if (!isa<llvm::PointerType>(Ops.LHS->getType())) { 1838 if (Ops.Ty->hasSignedIntegerRepresentation()) { 1839 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1840 case LangOptions::SOB_Undefined: 1841 return Builder.CreateNSWSub(Ops.LHS, Ops.RHS, "sub"); 1842 case LangOptions::SOB_Defined: 1843 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1844 case LangOptions::SOB_Trapping: 1845 return EmitOverflowCheckedBinOp(Ops); 1846 } 1847 } 1848 1849 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1850 return Builder.CreateFSub(Ops.LHS, Ops.RHS, "sub"); 1851 1852 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 1853 } 1854 1855 // Must have binary (not unary) expr here. Unary pointer increment doesn't 1856 // use this path. 1857 const BinaryOperator *BinOp = cast<BinaryOperator>(Ops.E); 1858 1859 if (BinOp->getLHS()->getType()->isPointerType() && 1860 BinOp->getLHS()->getType()->getAs<PointerType>()->isVariableArrayType()) { 1861 // The amount of the addition needs to account for the VLA size for 1862 // ptr-int 1863 // The amount of the division needs to account for the VLA size for 1864 // ptr-ptr. 1865 CGF.ErrorUnsupported(BinOp, "VLA pointer subtraction"); 1866 } 1867 1868 const QualType LHSType = BinOp->getLHS()->getType(); 1869 const QualType LHSElementType = LHSType->getPointeeType(); 1870 if (!isa<llvm::PointerType>(Ops.RHS->getType())) { 1871 // pointer - int 1872 Value *Idx = Ops.RHS; 1873 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 1874 if (Width < CGF.LLVMPointerWidth) { 1875 // Zero or sign extend the pointer value based on whether the index is 1876 // signed or not. 1877 const llvm::Type *IdxType = CGF.IntPtrTy; 1878 if (BinOp->getRHS()->getType()->isSignedIntegerType()) 1879 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 1880 else 1881 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 1882 } 1883 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); 1884 1885 // Handle interface types, which are not represented with a concrete type. 1886 if (const ObjCObjectType *OIT = LHSElementType->getAs<ObjCObjectType>()) { 1887 llvm::Value *InterfaceSize = 1888 llvm::ConstantInt::get(Idx->getType(), 1889 CGF.getContext(). 1890 getTypeSizeInChars(OIT).getQuantity()); 1891 Idx = Builder.CreateMul(Idx, InterfaceSize); 1892 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1893 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1894 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr"); 1895 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1896 } 1897 1898 // Explicitly handle GNU void* and function pointer arithmetic 1899 // extensions. The GNU void* casts amount to no-ops since our void* type is 1900 // i8*, but this is future proof. 1901 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1902 const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(VMContext); 1903 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 1904 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); 1905 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 1906 } 1907 1908 return Builder.CreateInBoundsGEP(Ops.LHS, Idx, "sub.ptr"); 1909 } else { 1910 // pointer - pointer 1911 Value *LHS = Ops.LHS; 1912 Value *RHS = Ops.RHS; 1913 1914 CharUnits ElementSize; 1915 1916 // Handle GCC extension for pointer arithmetic on void* and function pointer 1917 // types. 1918 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 1919 ElementSize = CharUnits::One(); 1920 } else { 1921 ElementSize = CGF.getContext().getTypeSizeInChars(LHSElementType); 1922 } 1923 1924 const llvm::Type *ResultType = ConvertType(Ops.Ty); 1925 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 1926 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 1927 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 1928 1929 // Optimize out the shift for element size of 1. 1930 if (ElementSize.isOne()) 1931 return BytesBetween; 1932 1933 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 1934 // pointer difference in C is only defined in the case where both operands 1935 // are pointing to elements of an array. 1936 Value *BytesPerElt = 1937 llvm::ConstantInt::get(ResultType, ElementSize.getQuantity()); 1938 return Builder.CreateExactSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 1939 } 1940} 1941 1942Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 1943 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1944 // RHS to the same size as the LHS. 1945 Value *RHS = Ops.RHS; 1946 if (Ops.LHS->getType() != RHS->getType()) 1947 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1948 1949 if (CGF.CatchUndefined 1950 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1951 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1952 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1953 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1954 llvm::ConstantInt::get(RHS->getType(), Width)), 1955 Cont, CGF.getTrapBB()); 1956 CGF.EmitBlock(Cont); 1957 } 1958 1959 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 1960} 1961 1962Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 1963 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1964 // RHS to the same size as the LHS. 1965 Value *RHS = Ops.RHS; 1966 if (Ops.LHS->getType() != RHS->getType()) 1967 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1968 1969 if (CGF.CatchUndefined 1970 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 1971 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 1972 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 1973 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 1974 llvm::ConstantInt::get(RHS->getType(), Width)), 1975 Cont, CGF.getTrapBB()); 1976 CGF.EmitBlock(Cont); 1977 } 1978 1979 if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1980 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 1981 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 1982} 1983 1984Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 1985 unsigned SICmpOpc, unsigned FCmpOpc) { 1986 TestAndClearIgnoreResultAssign(); 1987 Value *Result; 1988 QualType LHSTy = E->getLHS()->getType(); 1989 if (const MemberPointerType *MPT = LHSTy->getAs<MemberPointerType>()) { 1990 assert(E->getOpcode() == BO_EQ || 1991 E->getOpcode() == BO_NE); 1992 Value *LHS = CGF.EmitScalarExpr(E->getLHS()); 1993 Value *RHS = CGF.EmitScalarExpr(E->getRHS()); 1994 Result = CGF.CGM.getCXXABI().EmitMemberPointerComparison( 1995 CGF, LHS, RHS, MPT, E->getOpcode() == BO_NE); 1996 } else if (!LHSTy->isAnyComplexType()) { 1997 Value *LHS = Visit(E->getLHS()); 1998 Value *RHS = Visit(E->getRHS()); 1999 2000 if (LHS->getType()->isFPOrFPVectorTy()) { 2001 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 2002 LHS, RHS, "cmp"); 2003 } else if (LHSTy->hasSignedIntegerRepresentation()) { 2004 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 2005 LHS, RHS, "cmp"); 2006 } else { 2007 // Unsigned integers and pointers. 2008 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2009 LHS, RHS, "cmp"); 2010 } 2011 2012 // If this is a vector comparison, sign extend the result to the appropriate 2013 // vector integer type and return it (don't convert to bool). 2014 if (LHSTy->isVectorType()) 2015 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 2016 2017 } else { 2018 // Complex Comparison: can only be an equality comparison. 2019 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 2020 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 2021 2022 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 2023 2024 Value *ResultR, *ResultI; 2025 if (CETy->isRealFloatingType()) { 2026 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 2027 LHS.first, RHS.first, "cmp.r"); 2028 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 2029 LHS.second, RHS.second, "cmp.i"); 2030 } else { 2031 // Complex comparisons can only be equality comparisons. As such, signed 2032 // and unsigned opcodes are the same. 2033 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2034 LHS.first, RHS.first, "cmp.r"); 2035 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2036 LHS.second, RHS.second, "cmp.i"); 2037 } 2038 2039 if (E->getOpcode() == BO_EQ) { 2040 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 2041 } else { 2042 assert(E->getOpcode() == BO_NE && 2043 "Complex comparison other than == or != ?"); 2044 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 2045 } 2046 } 2047 2048 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 2049} 2050 2051Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 2052 bool Ignore = TestAndClearIgnoreResultAssign(); 2053 2054 // __block variables need to have the rhs evaluated first, plus this should 2055 // improve codegen just a little. 2056 Value *RHS = Visit(E->getRHS()); 2057 LValue LHS = EmitCheckedLValue(E->getLHS()); 2058 2059 // Store the value into the LHS. Bit-fields are handled specially 2060 // because the result is altered by the store, i.e., [C99 6.5.16p1] 2061 // 'An assignment expression has the value of the left operand after 2062 // the assignment...'. 2063 if (LHS.isBitField()) 2064 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), 2065 &RHS); 2066 else 2067 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 2068 2069 // If the result is clearly ignored, return now. 2070 if (Ignore) 2071 return 0; 2072 2073 // The result of an assignment in C is the assigned r-value. 2074 if (!CGF.getContext().getLangOptions().CPlusPlus) 2075 return RHS; 2076 2077 // Objective-C property assignment never reloads the value following a store. 2078 if (LHS.isPropertyRef() || LHS.isKVCRef()) 2079 return RHS; 2080 2081 // If the lvalue is non-volatile, return the computed value of the assignment. 2082 if (!LHS.isVolatileQualified()) 2083 return RHS; 2084 2085 // Otherwise, reload the value. 2086 return EmitLoadOfLValue(LHS, E->getType()); 2087} 2088 2089Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 2090 const llvm::Type *ResTy = ConvertType(E->getType()); 2091 2092 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 2093 // If we have 1 && X, just emit X without inserting the control flow. 2094 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 2095 if (Cond == 1) { // If we have 1 && X, just emit X. 2096 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2097 // ZExt result to int or bool. 2098 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 2099 } 2100 2101 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 2102 if (!CGF.ContainsLabel(E->getRHS())) 2103 return llvm::Constant::getNullValue(ResTy); 2104 } 2105 2106 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 2107 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 2108 2109 // Branch on the LHS first. If it is false, go to the failure (cont) block. 2110 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 2111 2112 // Any edges into the ContBlock are now from an (indeterminate number of) 2113 // edges from this first condition. All of these values will be false. Start 2114 // setting up the PHI node in the Cont Block for this. 2115 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2116 "", ContBlock); 2117 PN->reserveOperandSpace(2); // Normal case, two inputs. 2118 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 2119 PI != PE; ++PI) 2120 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 2121 2122 CGF.BeginConditionalBranch(); 2123 CGF.EmitBlock(RHSBlock); 2124 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2125 CGF.EndConditionalBranch(); 2126 2127 // Reaquire the RHS block, as there may be subblocks inserted. 2128 RHSBlock = Builder.GetInsertBlock(); 2129 2130 // Emit an unconditional branch from this block to ContBlock. Insert an entry 2131 // into the phi node for the edge with the value of RHSCond. 2132 CGF.EmitBlock(ContBlock); 2133 PN->addIncoming(RHSCond, RHSBlock); 2134 2135 // ZExt result to int. 2136 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); 2137} 2138 2139Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 2140 const llvm::Type *ResTy = ConvertType(E->getType()); 2141 2142 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 2143 // If we have 0 || X, just emit X without inserting the control flow. 2144 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 2145 if (Cond == -1) { // If we have 0 || X, just emit X. 2146 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2147 // ZExt result to int or bool. 2148 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 2149 } 2150 2151 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 2152 if (!CGF.ContainsLabel(E->getRHS())) 2153 return llvm::ConstantInt::get(ResTy, 1); 2154 } 2155 2156 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 2157 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 2158 2159 // Branch on the LHS first. If it is true, go to the success (cont) block. 2160 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 2161 2162 // Any edges into the ContBlock are now from an (indeterminate number of) 2163 // edges from this first condition. All of these values will be true. Start 2164 // setting up the PHI node in the Cont Block for this. 2165 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2166 "", ContBlock); 2167 PN->reserveOperandSpace(2); // Normal case, two inputs. 2168 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 2169 PI != PE; ++PI) 2170 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 2171 2172 CGF.BeginConditionalBranch(); 2173 2174 // Emit the RHS condition as a bool value. 2175 CGF.EmitBlock(RHSBlock); 2176 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2177 2178 CGF.EndConditionalBranch(); 2179 2180 // Reaquire the RHS block, as there may be subblocks inserted. 2181 RHSBlock = Builder.GetInsertBlock(); 2182 2183 // Emit an unconditional branch from this block to ContBlock. Insert an entry 2184 // into the phi node for the edge with the value of RHSCond. 2185 CGF.EmitBlock(ContBlock); 2186 PN->addIncoming(RHSCond, RHSBlock); 2187 2188 // ZExt result to int. 2189 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 2190} 2191 2192Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 2193 CGF.EmitStmt(E->getLHS()); 2194 CGF.EnsureInsertPoint(); 2195 return Visit(E->getRHS()); 2196} 2197 2198//===----------------------------------------------------------------------===// 2199// Other Operators 2200//===----------------------------------------------------------------------===// 2201 2202/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 2203/// expression is cheap enough and side-effect-free enough to evaluate 2204/// unconditionally instead of conditionally. This is used to convert control 2205/// flow into selects in some cases. 2206static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 2207 CodeGenFunction &CGF) { 2208 if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) 2209 return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr(), CGF); 2210 2211 // TODO: Allow anything we can constant fold to an integer or fp constant. 2212 if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || 2213 isa<FloatingLiteral>(E)) 2214 return true; 2215 2216 // Non-volatile automatic variables too, to get "cond ? X : Y" where 2217 // X and Y are local variables. 2218 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 2219 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 2220 if (VD->hasLocalStorage() && !(CGF.getContext() 2221 .getCanonicalType(VD->getType()) 2222 .isVolatileQualified())) 2223 return true; 2224 2225 return false; 2226} 2227 2228 2229Value *ScalarExprEmitter:: 2230VisitConditionalOperator(const ConditionalOperator *E) { 2231 TestAndClearIgnoreResultAssign(); 2232 // If the condition constant folds and can be elided, try to avoid emitting 2233 // the condition and the dead arm. 2234 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ 2235 Expr *Live = E->getLHS(), *Dead = E->getRHS(); 2236 if (Cond == -1) 2237 std::swap(Live, Dead); 2238 2239 // If the dead side doesn't have labels we need, and if the Live side isn't 2240 // the gnu missing ?: extension (which we could handle, but don't bother 2241 // to), just emit the Live part. 2242 if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part 2243 Live) // Live part isn't missing. 2244 return Visit(Live); 2245 } 2246 2247 // OpenCL: If the condition is a vector, we can treat this condition like 2248 // the select function. 2249 if (CGF.getContext().getLangOptions().OpenCL 2250 && E->getCond()->getType()->isVectorType()) { 2251 llvm::Value *CondV = CGF.EmitScalarExpr(E->getCond()); 2252 llvm::Value *LHS = Visit(E->getLHS()); 2253 llvm::Value *RHS = Visit(E->getRHS()); 2254 2255 const llvm::Type *condType = ConvertType(E->getCond()->getType()); 2256 const llvm::VectorType *vecTy = cast<llvm::VectorType>(condType); 2257 2258 unsigned numElem = vecTy->getNumElements(); 2259 const llvm::Type *elemType = vecTy->getElementType(); 2260 2261 std::vector<llvm::Constant*> Zvals; 2262 for (unsigned i = 0; i < numElem; ++i) 2263 Zvals.push_back(llvm::ConstantInt::get(elemType,0)); 2264 2265 llvm::Value *zeroVec = llvm::ConstantVector::get(Zvals); 2266 llvm::Value *TestMSB = Builder.CreateICmpSLT(CondV, zeroVec); 2267 llvm::Value *tmp = Builder.CreateSExt(TestMSB, 2268 llvm::VectorType::get(elemType, 2269 numElem), 2270 "sext"); 2271 llvm::Value *tmp2 = Builder.CreateNot(tmp); 2272 2273 // Cast float to int to perform ANDs if necessary. 2274 llvm::Value *RHSTmp = RHS; 2275 llvm::Value *LHSTmp = LHS; 2276 bool wasCast = false; 2277 const llvm::VectorType *rhsVTy = cast<llvm::VectorType>(RHS->getType()); 2278 if (rhsVTy->getElementType()->isFloatTy()) { 2279 RHSTmp = Builder.CreateBitCast(RHS, tmp2->getType()); 2280 LHSTmp = Builder.CreateBitCast(LHS, tmp->getType()); 2281 wasCast = true; 2282 } 2283 2284 llvm::Value *tmp3 = Builder.CreateAnd(RHSTmp, tmp2); 2285 llvm::Value *tmp4 = Builder.CreateAnd(LHSTmp, tmp); 2286 llvm::Value *tmp5 = Builder.CreateOr(tmp3, tmp4, "cond"); 2287 if (wasCast) 2288 tmp5 = Builder.CreateBitCast(tmp5, RHS->getType()); 2289 2290 return tmp5; 2291 } 2292 2293 // If this is a really simple expression (like x ? 4 : 5), emit this as a 2294 // select instead of as control flow. We can only do this if it is cheap and 2295 // safe to evaluate the LHS and RHS unconditionally. 2296 if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS(), 2297 CGF) && 2298 isCheapEnoughToEvaluateUnconditionally(E->getRHS(), CGF)) { 2299 llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); 2300 llvm::Value *LHS = Visit(E->getLHS()); 2301 llvm::Value *RHS = Visit(E->getRHS()); 2302 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 2303 } 2304 2305 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 2306 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 2307 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 2308 2309 // If we don't have the GNU missing condition extension, emit a branch on bool 2310 // the normal way. 2311 if (E->getLHS()) { 2312 // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for 2313 // the branch on bool. 2314 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); 2315 } else { 2316 // Otherwise, for the ?: extension, evaluate the conditional and then 2317 // convert it to bool the hard way. We do this explicitly because we need 2318 // the unconverted value for the missing middle value of the ?:. 2319 Expr *save = E->getSAVE(); 2320 assert(save && "VisitConditionalOperator - save is null"); 2321 // Intentianlly not doing direct assignment to ConditionalSaveExprs[save] !! 2322 Value *SaveVal = CGF.EmitScalarExpr(save); 2323 CGF.ConditionalSaveExprs[save] = SaveVal; 2324 Value *CondVal = Visit(E->getCond()); 2325 // In some cases, EmitScalarConversion will delete the "CondVal" expression 2326 // if there are no extra uses (an optimization). Inhibit this by making an 2327 // extra dead use, because we're going to add a use of CondVal later. We 2328 // don't use the builder for this, because we don't want it to get optimized 2329 // away. This leaves dead code, but the ?: extension isn't common. 2330 new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", 2331 Builder.GetInsertBlock()); 2332 2333 Value *CondBoolVal = 2334 CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 2335 CGF.getContext().BoolTy); 2336 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 2337 } 2338 2339 CGF.BeginConditionalBranch(); 2340 CGF.EmitBlock(LHSBlock); 2341 2342 // Handle the GNU extension for missing LHS. 2343 Value *LHS = Visit(E->getTrueExpr()); 2344 2345 CGF.EndConditionalBranch(); 2346 LHSBlock = Builder.GetInsertBlock(); 2347 CGF.EmitBranch(ContBlock); 2348 2349 CGF.BeginConditionalBranch(); 2350 CGF.EmitBlock(RHSBlock); 2351 2352 Value *RHS = Visit(E->getRHS()); 2353 CGF.EndConditionalBranch(); 2354 RHSBlock = Builder.GetInsertBlock(); 2355 CGF.EmitBranch(ContBlock); 2356 2357 CGF.EmitBlock(ContBlock); 2358 2359 // If the LHS or RHS is a throw expression, it will be legitimately null. 2360 if (!LHS) 2361 return RHS; 2362 if (!RHS) 2363 return LHS; 2364 2365 // Create a PHI node for the real part. 2366 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 2367 PN->reserveOperandSpace(2); 2368 PN->addIncoming(LHS, LHSBlock); 2369 PN->addIncoming(RHS, RHSBlock); 2370 return PN; 2371} 2372 2373Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 2374 return Visit(E->getChosenSubExpr(CGF.getContext())); 2375} 2376 2377Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 2378 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 2379 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 2380 2381 // If EmitVAArg fails, we fall back to the LLVM instruction. 2382 if (!ArgPtr) 2383 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 2384 2385 // FIXME Volatility. 2386 return Builder.CreateLoad(ArgPtr); 2387} 2388 2389Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { 2390 return CGF.BuildBlockLiteralTmp(BE); 2391} 2392 2393//===----------------------------------------------------------------------===// 2394// Entry Point into this File 2395//===----------------------------------------------------------------------===// 2396 2397/// EmitScalarExpr - Emit the computation of the specified expression of scalar 2398/// type, ignoring the result. 2399Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 2400 assert(E && !hasAggregateLLVMType(E->getType()) && 2401 "Invalid scalar expression to emit"); 2402 2403 return ScalarExprEmitter(*this, IgnoreResultAssign) 2404 .Visit(const_cast<Expr*>(E)); 2405} 2406 2407/// EmitScalarConversion - Emit a conversion from the specified type to the 2408/// specified destination type, both of which are LLVM scalar types. 2409Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 2410 QualType DstTy) { 2411 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 2412 "Invalid scalar expression to emit"); 2413 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 2414} 2415 2416/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 2417/// type to the specified destination type, where the destination type is an 2418/// LLVM scalar type. 2419Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 2420 QualType SrcTy, 2421 QualType DstTy) { 2422 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 2423 "Invalid complex -> scalar conversion"); 2424 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 2425 DstTy); 2426} 2427 2428 2429llvm::Value *CodeGenFunction:: 2430EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 2431 bool isInc, bool isPre) { 2432 return ScalarExprEmitter(*this).EmitScalarPrePostIncDec(E, LV, isInc, isPre); 2433} 2434 2435LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) { 2436 llvm::Value *V; 2437 // object->isa or (*object).isa 2438 // Generate code as for: *(Class*)object 2439 // build Class* type 2440 const llvm::Type *ClassPtrTy = ConvertType(E->getType()); 2441 2442 Expr *BaseExpr = E->getBase(); 2443 if (BaseExpr->isLvalue(getContext()) != Expr::LV_Valid) { 2444 V = CreateTempAlloca(ClassPtrTy, "resval"); 2445 llvm::Value *Src = EmitScalarExpr(BaseExpr); 2446 Builder.CreateStore(Src, V); 2447 V = ScalarExprEmitter(*this).EmitLoadOfLValue( 2448 MakeAddrLValue(V, E->getType()), E->getType()); 2449 } else { 2450 if (E->isArrow()) 2451 V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr); 2452 else 2453 V = EmitLValue(BaseExpr).getAddress(); 2454 } 2455 2456 // build Class* type 2457 ClassPtrTy = ClassPtrTy->getPointerTo(); 2458 V = Builder.CreateBitCast(V, ClassPtrTy); 2459 return MakeAddrLValue(V, E->getType()); 2460} 2461 2462 2463LValue CodeGenFunction::EmitCompoundAssignOperatorLValue( 2464 const CompoundAssignOperator *E) { 2465 ScalarExprEmitter Scalar(*this); 2466 Value *Result = 0; 2467 switch (E->getOpcode()) { 2468#define COMPOUND_OP(Op) \ 2469 case BO_##Op##Assign: \ 2470 return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \ 2471 Result) 2472 COMPOUND_OP(Mul); 2473 COMPOUND_OP(Div); 2474 COMPOUND_OP(Rem); 2475 COMPOUND_OP(Add); 2476 COMPOUND_OP(Sub); 2477 COMPOUND_OP(Shl); 2478 COMPOUND_OP(Shr); 2479 COMPOUND_OP(And); 2480 COMPOUND_OP(Xor); 2481 COMPOUND_OP(Or); 2482#undef COMPOUND_OP 2483 2484 case BO_PtrMemD: 2485 case BO_PtrMemI: 2486 case BO_Mul: 2487 case BO_Div: 2488 case BO_Rem: 2489 case BO_Add: 2490 case BO_Sub: 2491 case BO_Shl: 2492 case BO_Shr: 2493 case BO_LT: 2494 case BO_GT: 2495 case BO_LE: 2496 case BO_GE: 2497 case BO_EQ: 2498 case BO_NE: 2499 case BO_And: 2500 case BO_Xor: 2501 case BO_Or: 2502 case BO_LAnd: 2503 case BO_LOr: 2504 case BO_Assign: 2505 case BO_Comma: 2506 assert(false && "Not valid compound assignment operators"); 2507 break; 2508 } 2509 2510 llvm_unreachable("Unhandled compound assignment operator"); 2511} 2512