CGExprScalar.cpp revision 348f16fc7c71f0d9b651cb79fd1012843073493f
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 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) { 86 return CGF.EmitLoadOfLValue(LV).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)); 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 return Builder.CreateIsNotNull(V, "tobool"); 144 } 145 146 //===--------------------------------------------------------------------===// 147 // Visitor Methods 148 //===--------------------------------------------------------------------===// 149 150 Value *Visit(Expr *E) { 151 return StmtVisitor<ScalarExprEmitter, Value*>::Visit(E); 152 } 153 154 Value *VisitStmt(Stmt *S) { 155 S->dump(CGF.getContext().getSourceManager()); 156 llvm_unreachable("Stmt can't have complex result type!"); 157 } 158 Value *VisitExpr(Expr *S); 159 160 Value *VisitParenExpr(ParenExpr *PE) { 161 return Visit(PE->getSubExpr()); 162 } 163 Value *VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) { 164 return Visit(E->getReplacement()); 165 } 166 Value *VisitGenericSelectionExpr(GenericSelectionExpr *GE) { 167 return Visit(GE->getResultExpr()); 168 } 169 170 // Leaves. 171 Value *VisitIntegerLiteral(const IntegerLiteral *E) { 172 return Builder.getInt(E->getValue()); 173 } 174 Value *VisitFloatingLiteral(const FloatingLiteral *E) { 175 return llvm::ConstantFP::get(VMContext, E->getValue()); 176 } 177 Value *VisitCharacterLiteral(const CharacterLiteral *E) { 178 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 179 } 180 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 181 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 182 } 183 Value *VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) { 184 return EmitNullValue(E->getType()); 185 } 186 Value *VisitGNUNullExpr(const GNUNullExpr *E) { 187 return EmitNullValue(E->getType()); 188 } 189 Value *VisitOffsetOfExpr(OffsetOfExpr *E); 190 Value *VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E); 191 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 192 llvm::Value *V = CGF.GetAddrOfLabel(E->getLabel()); 193 return Builder.CreateBitCast(V, ConvertType(E->getType())); 194 } 195 196 Value *VisitSizeOfPackExpr(SizeOfPackExpr *E) { 197 return llvm::ConstantInt::get(ConvertType(E->getType()),E->getPackLength()); 198 } 199 200 Value *VisitOpaqueValueExpr(OpaqueValueExpr *E) { 201 if (E->isGLValue()) 202 return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E)); 203 204 // Otherwise, assume the mapping is the scalar directly. 205 return CGF.getOpaqueRValueMapping(E).getScalarVal(); 206 } 207 208 // l-values. 209 Value *VisitDeclRefExpr(DeclRefExpr *E) { 210 Expr::EvalResult Result; 211 if (!E->Evaluate(Result, CGF.getContext())) 212 return EmitLoadOfLValue(E); 213 214 assert(!Result.HasSideEffects && "Constant declref with side-effect?!"); 215 216 llvm::Constant *C; 217 if (Result.Val.isInt()) 218 C = Builder.getInt(Result.Val.getInt()); 219 else if (Result.Val.isFloat()) 220 C = llvm::ConstantFP::get(VMContext, Result.Val.getFloat()); 221 else 222 return EmitLoadOfLValue(E); 223 224 // Make sure we emit a debug reference to the global variable. 225 if (VarDecl *VD = dyn_cast<VarDecl>(E->getDecl())) { 226 if (!CGF.getContext().DeclMustBeEmitted(VD)) 227 CGF.EmitDeclRefExprDbgValue(E, C); 228 } else if (isa<EnumConstantDecl>(E->getDecl())) { 229 CGF.EmitDeclRefExprDbgValue(E, C); 230 } 231 232 return C; 233 } 234 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 235 return CGF.EmitObjCSelectorExpr(E); 236 } 237 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 238 return CGF.EmitObjCProtocolExpr(E); 239 } 240 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 241 return EmitLoadOfLValue(E); 242 } 243 Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { 244 assert(E->getObjectKind() == OK_Ordinary && 245 "reached property reference without lvalue-to-rvalue"); 246 return EmitLoadOfLValue(E); 247 } 248 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 249 if (E->getMethodDecl() && 250 E->getMethodDecl()->getResultType()->isReferenceType()) 251 return EmitLoadOfLValue(E); 252 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 253 } 254 255 Value *VisitObjCIsaExpr(ObjCIsaExpr *E) { 256 LValue LV = CGF.EmitObjCIsaExpr(E); 257 Value *V = CGF.EmitLoadOfLValue(LV).getScalarVal(); 258 return V; 259 } 260 261 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 262 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 263 Value *VisitMemberExpr(MemberExpr *E); 264 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 265 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 266 return EmitLoadOfLValue(E); 267 } 268 269 Value *VisitInitListExpr(InitListExpr *E); 270 271 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { 272 return CGF.CGM.EmitNullConstant(E->getType()); 273 } 274 Value *VisitExplicitCastExpr(ExplicitCastExpr *E) { 275 if (E->getType()->isVariablyModifiedType()) 276 CGF.EmitVariablyModifiedType(E->getType()); 277 return VisitCastExpr(E); 278 } 279 Value *VisitCastExpr(CastExpr *E); 280 281 Value *VisitCallExpr(const CallExpr *E) { 282 if (E->getCallReturnType()->isReferenceType()) 283 return EmitLoadOfLValue(E); 284 285 return CGF.EmitCallExpr(E).getScalarVal(); 286 } 287 288 Value *VisitStmtExpr(const StmtExpr *E); 289 290 Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E); 291 292 // Unary Operators. 293 Value *VisitUnaryPostDec(const UnaryOperator *E) { 294 LValue LV = EmitLValue(E->getSubExpr()); 295 return EmitScalarPrePostIncDec(E, LV, false, false); 296 } 297 Value *VisitUnaryPostInc(const UnaryOperator *E) { 298 LValue LV = EmitLValue(E->getSubExpr()); 299 return EmitScalarPrePostIncDec(E, LV, true, false); 300 } 301 Value *VisitUnaryPreDec(const UnaryOperator *E) { 302 LValue LV = EmitLValue(E->getSubExpr()); 303 return EmitScalarPrePostIncDec(E, LV, false, true); 304 } 305 Value *VisitUnaryPreInc(const UnaryOperator *E) { 306 LValue LV = EmitLValue(E->getSubExpr()); 307 return EmitScalarPrePostIncDec(E, LV, true, true); 308 } 309 310 llvm::Value *EmitAddConsiderOverflowBehavior(const UnaryOperator *E, 311 llvm::Value *InVal, 312 llvm::Value *NextVal, 313 bool IsInc); 314 315 llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 316 bool isInc, bool isPre); 317 318 319 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 320 if (isa<MemberPointerType>(E->getType())) // never sugared 321 return CGF.CGM.getMemberPointerConstant(E); 322 323 return EmitLValue(E->getSubExpr()).getAddress(); 324 } 325 Value *VisitUnaryDeref(const UnaryOperator *E) { 326 if (E->getType()->isVoidType()) 327 return Visit(E->getSubExpr()); // the actual value should be unused 328 return EmitLoadOfLValue(E); 329 } 330 Value *VisitUnaryPlus(const UnaryOperator *E) { 331 // This differs from gcc, though, most likely due to a bug in gcc. 332 TestAndClearIgnoreResultAssign(); 333 return Visit(E->getSubExpr()); 334 } 335 Value *VisitUnaryMinus (const UnaryOperator *E); 336 Value *VisitUnaryNot (const UnaryOperator *E); 337 Value *VisitUnaryLNot (const UnaryOperator *E); 338 Value *VisitUnaryReal (const UnaryOperator *E); 339 Value *VisitUnaryImag (const UnaryOperator *E); 340 Value *VisitUnaryExtension(const UnaryOperator *E) { 341 return Visit(E->getSubExpr()); 342 } 343 344 // C++ 345 Value *VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E) { 346 return EmitLoadOfLValue(E); 347 } 348 349 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 350 return Visit(DAE->getExpr()); 351 } 352 Value *VisitCXXThisExpr(CXXThisExpr *TE) { 353 return CGF.LoadCXXThis(); 354 } 355 356 Value *VisitExprWithCleanups(ExprWithCleanups *E) { 357 return CGF.EmitExprWithCleanups(E).getScalarVal(); 358 } 359 Value *VisitCXXNewExpr(const CXXNewExpr *E) { 360 return CGF.EmitCXXNewExpr(E); 361 } 362 Value *VisitCXXDeleteExpr(const CXXDeleteExpr *E) { 363 CGF.EmitCXXDeleteExpr(E); 364 return 0; 365 } 366 Value *VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) { 367 return Builder.getInt1(E->getValue()); 368 } 369 370 Value *VisitBinaryTypeTraitExpr(const BinaryTypeTraitExpr *E) { 371 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 372 } 373 374 Value *VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) { 375 return llvm::ConstantInt::get(Builder.getInt32Ty(), E->getValue()); 376 } 377 378 Value *VisitExpressionTraitExpr(const ExpressionTraitExpr *E) { 379 return llvm::ConstantInt::get(Builder.getInt1Ty(), E->getValue()); 380 } 381 382 Value *VisitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E) { 383 // C++ [expr.pseudo]p1: 384 // The result shall only be used as the operand for the function call 385 // operator (), and the result of such a call has type void. The only 386 // effect is the evaluation of the postfix-expression before the dot or 387 // arrow. 388 CGF.EmitScalarExpr(E->getBase()); 389 return 0; 390 } 391 392 Value *VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) { 393 return EmitNullValue(E->getType()); 394 } 395 396 Value *VisitCXXThrowExpr(const CXXThrowExpr *E) { 397 CGF.EmitCXXThrowExpr(E); 398 return 0; 399 } 400 401 Value *VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) { 402 return Builder.getInt1(E->getValue()); 403 } 404 405 // Binary Operators. 406 Value *EmitMul(const BinOpInfo &Ops) { 407 if (Ops.Ty->isSignedIntegerOrEnumerationType()) { 408 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 409 case LangOptions::SOB_Undefined: 410 return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul"); 411 case LangOptions::SOB_Defined: 412 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 413 case LangOptions::SOB_Trapping: 414 return EmitOverflowCheckedBinOp(Ops); 415 } 416 } 417 418 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 419 return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul"); 420 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 421 } 422 bool isTrapvOverflowBehavior() { 423 return CGF.getContext().getLangOptions().getSignedOverflowBehavior() 424 == LangOptions::SOB_Trapping; 425 } 426 /// Create a binary op that checks for overflow. 427 /// Currently only supports +, - and *. 428 Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); 429 // Emit the overflow BB when -ftrapv option is activated. 430 void EmitOverflowBB(llvm::BasicBlock *overflowBB) { 431 Builder.SetInsertPoint(overflowBB); 432 llvm::Function *Trap = CGF.CGM.getIntrinsic(llvm::Intrinsic::trap); 433 Builder.CreateCall(Trap); 434 Builder.CreateUnreachable(); 435 } 436 // Check for undefined division and modulus behaviors. 437 void EmitUndefinedBehaviorIntegerDivAndRemCheck(const BinOpInfo &Ops, 438 llvm::Value *Zero,bool isDiv); 439 Value *EmitDiv(const BinOpInfo &Ops); 440 Value *EmitRem(const BinOpInfo &Ops); 441 Value *EmitAdd(const BinOpInfo &Ops); 442 Value *EmitSub(const BinOpInfo &Ops); 443 Value *EmitShl(const BinOpInfo &Ops); 444 Value *EmitShr(const BinOpInfo &Ops); 445 Value *EmitAnd(const BinOpInfo &Ops) { 446 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 447 } 448 Value *EmitXor(const BinOpInfo &Ops) { 449 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 450 } 451 Value *EmitOr (const BinOpInfo &Ops) { 452 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 453 } 454 455 BinOpInfo EmitBinOps(const BinaryOperator *E); 456 LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E, 457 Value *(ScalarExprEmitter::*F)(const BinOpInfo &), 458 Value *&Result); 459 460 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 461 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 462 463 // Binary operators and binary compound assignment operators. 464#define HANDLEBINOP(OP) \ 465 Value *VisitBin ## OP(const BinaryOperator *E) { \ 466 return Emit ## OP(EmitBinOps(E)); \ 467 } \ 468 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 469 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 470 } 471 HANDLEBINOP(Mul) 472 HANDLEBINOP(Div) 473 HANDLEBINOP(Rem) 474 HANDLEBINOP(Add) 475 HANDLEBINOP(Sub) 476 HANDLEBINOP(Shl) 477 HANDLEBINOP(Shr) 478 HANDLEBINOP(And) 479 HANDLEBINOP(Xor) 480 HANDLEBINOP(Or) 481#undef HANDLEBINOP 482 483 // Comparisons. 484 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 485 unsigned SICmpOpc, unsigned FCmpOpc); 486#define VISITCOMP(CODE, UI, SI, FP) \ 487 Value *VisitBin##CODE(const BinaryOperator *E) { \ 488 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 489 llvm::FCmpInst::FP); } 490 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT) 491 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT) 492 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE) 493 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE) 494 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ) 495 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE) 496#undef VISITCOMP 497 498 Value *VisitBinAssign (const BinaryOperator *E); 499 500 Value *VisitBinLAnd (const BinaryOperator *E); 501 Value *VisitBinLOr (const BinaryOperator *E); 502 Value *VisitBinComma (const BinaryOperator *E); 503 504 Value *VisitBinPtrMemD(const Expr *E) { return EmitLoadOfLValue(E); } 505 Value *VisitBinPtrMemI(const Expr *E) { return EmitLoadOfLValue(E); } 506 507 // Other Operators. 508 Value *VisitBlockExpr(const BlockExpr *BE); 509 Value *VisitAbstractConditionalOperator(const AbstractConditionalOperator *); 510 Value *VisitChooseExpr(ChooseExpr *CE); 511 Value *VisitVAArgExpr(VAArgExpr *VE); 512 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 513 return CGF.EmitObjCStringLiteral(E); 514 } 515 Value *VisitAsTypeExpr(AsTypeExpr *CE); 516}; 517} // end anonymous namespace. 518 519//===----------------------------------------------------------------------===// 520// Utilities 521//===----------------------------------------------------------------------===// 522 523/// EmitConversionToBool - Convert the specified expression value to a 524/// boolean (i1) truth value. This is equivalent to "Val != 0". 525Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 526 assert(SrcType.isCanonical() && "EmitScalarConversion strips typedefs"); 527 528 if (SrcType->isRealFloatingType()) 529 return EmitFloatToBoolConversion(Src); 530 531 if (const MemberPointerType *MPT = dyn_cast<MemberPointerType>(SrcType)) 532 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, Src, MPT); 533 534 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 535 "Unknown scalar type to convert"); 536 537 if (isa<llvm::IntegerType>(Src->getType())) 538 return EmitIntToBoolConversion(Src); 539 540 assert(isa<llvm::PointerType>(Src->getType())); 541 return EmitPointerToBoolConversion(Src); 542} 543 544/// EmitScalarConversion - Emit a conversion from the specified type to the 545/// specified destination type, both of which are LLVM scalar types. 546Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 547 QualType DstType) { 548 SrcType = CGF.getContext().getCanonicalType(SrcType); 549 DstType = CGF.getContext().getCanonicalType(DstType); 550 if (SrcType == DstType) return Src; 551 552 if (DstType->isVoidType()) return 0; 553 554 // Handle conversions to bool first, they are special: comparisons against 0. 555 if (DstType->isBooleanType()) 556 return EmitConversionToBool(Src, SrcType); 557 558 llvm::Type *DstTy = ConvertType(DstType); 559 560 // Ignore conversions like int -> uint. 561 if (Src->getType() == DstTy) 562 return Src; 563 564 // Handle pointer conversions next: pointers can only be converted to/from 565 // other pointers and integers. Check for pointer types in terms of LLVM, as 566 // some native types (like Obj-C id) may map to a pointer type. 567 if (isa<llvm::PointerType>(DstTy)) { 568 // The source value may be an integer, or a pointer. 569 if (isa<llvm::PointerType>(Src->getType())) 570 return Builder.CreateBitCast(Src, DstTy, "conv"); 571 572 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 573 // First, convert to the correct width so that we control the kind of 574 // extension. 575 llvm::Type *MiddleTy = CGF.IntPtrTy; 576 bool InputSigned = SrcType->isSignedIntegerOrEnumerationType(); 577 llvm::Value* IntResult = 578 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 579 // Then, cast to pointer. 580 return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); 581 } 582 583 if (isa<llvm::PointerType>(Src->getType())) { 584 // Must be an ptr to int cast. 585 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 586 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 587 } 588 589 // A scalar can be splatted to an extended vector of the same element type 590 if (DstType->isExtVectorType() && !SrcType->isVectorType()) { 591 // Cast the scalar to element type 592 QualType EltTy = DstType->getAs<ExtVectorType>()->getElementType(); 593 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 594 595 // Insert the element in element zero of an undef vector 596 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 597 llvm::Value *Idx = Builder.getInt32(0); 598 UnV = Builder.CreateInsertElement(UnV, Elt, Idx); 599 600 // Splat the element across to all elements 601 SmallVector<llvm::Constant*, 16> Args; 602 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 603 for (unsigned i = 0; i != NumElements; ++i) 604 Args.push_back(Builder.getInt32(0)); 605 606 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 607 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 608 return Yay; 609 } 610 611 // Allow bitcast from vector to integer/fp of the same size. 612 if (isa<llvm::VectorType>(Src->getType()) || 613 isa<llvm::VectorType>(DstTy)) 614 return Builder.CreateBitCast(Src, DstTy, "conv"); 615 616 // Finally, we have the arithmetic types: real int/float. 617 if (isa<llvm::IntegerType>(Src->getType())) { 618 bool InputSigned = SrcType->isSignedIntegerOrEnumerationType(); 619 if (isa<llvm::IntegerType>(DstTy)) 620 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 621 else if (InputSigned) 622 return Builder.CreateSIToFP(Src, DstTy, "conv"); 623 else 624 return Builder.CreateUIToFP(Src, DstTy, "conv"); 625 } 626 627 assert(Src->getType()->isFloatingPointTy() && "Unknown real conversion"); 628 if (isa<llvm::IntegerType>(DstTy)) { 629 if (DstType->isSignedIntegerOrEnumerationType()) 630 return Builder.CreateFPToSI(Src, DstTy, "conv"); 631 else 632 return Builder.CreateFPToUI(Src, DstTy, "conv"); 633 } 634 635 assert(DstTy->isFloatingPointTy() && "Unknown real conversion"); 636 if (DstTy->getTypeID() < Src->getType()->getTypeID()) 637 return Builder.CreateFPTrunc(Src, DstTy, "conv"); 638 else 639 return Builder.CreateFPExt(Src, DstTy, "conv"); 640} 641 642/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 643/// type to the specified destination type, where the destination type is an 644/// LLVM scalar type. 645Value *ScalarExprEmitter:: 646EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 647 QualType SrcTy, QualType DstTy) { 648 // Get the source element type. 649 SrcTy = SrcTy->getAs<ComplexType>()->getElementType(); 650 651 // Handle conversions to bool first, they are special: comparisons against 0. 652 if (DstTy->isBooleanType()) { 653 // Complex != 0 -> (Real != 0) | (Imag != 0) 654 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 655 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 656 return Builder.CreateOr(Src.first, Src.second, "tobool"); 657 } 658 659 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 660 // the imaginary part of the complex value is discarded and the value of the 661 // real part is converted according to the conversion rules for the 662 // corresponding real type. 663 return EmitScalarConversion(Src.first, SrcTy, DstTy); 664} 665 666Value *ScalarExprEmitter::EmitNullValue(QualType Ty) { 667 if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>()) 668 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 669 670 return llvm::Constant::getNullValue(ConvertType(Ty)); 671} 672 673//===----------------------------------------------------------------------===// 674// Visitor Methods 675//===----------------------------------------------------------------------===// 676 677Value *ScalarExprEmitter::VisitExpr(Expr *E) { 678 CGF.ErrorUnsupported(E, "scalar expression"); 679 if (E->getType()->isVoidType()) 680 return 0; 681 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 682} 683 684Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 685 // Vector Mask Case 686 if (E->getNumSubExprs() == 2 || 687 (E->getNumSubExprs() == 3 && E->getExpr(2)->getType()->isVectorType())) { 688 Value *LHS = CGF.EmitScalarExpr(E->getExpr(0)); 689 Value *RHS = CGF.EmitScalarExpr(E->getExpr(1)); 690 Value *Mask; 691 692 llvm::VectorType *LTy = cast<llvm::VectorType>(LHS->getType()); 693 unsigned LHSElts = LTy->getNumElements(); 694 695 if (E->getNumSubExprs() == 3) { 696 Mask = CGF.EmitScalarExpr(E->getExpr(2)); 697 698 // Shuffle LHS & RHS into one input vector. 699 SmallVector<llvm::Constant*, 32> concat; 700 for (unsigned i = 0; i != LHSElts; ++i) { 701 concat.push_back(Builder.getInt32(2*i)); 702 concat.push_back(Builder.getInt32(2*i+1)); 703 } 704 705 Value* CV = llvm::ConstantVector::get(concat); 706 LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat"); 707 LHSElts *= 2; 708 } else { 709 Mask = RHS; 710 } 711 712 llvm::VectorType *MTy = cast<llvm::VectorType>(Mask->getType()); 713 llvm::Constant* EltMask; 714 715 // Treat vec3 like vec4. 716 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) 717 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 718 (1 << llvm::Log2_32(LHSElts+2))-1); 719 else if ((LHSElts == 3) && (E->getNumSubExprs() == 2)) 720 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 721 (1 << llvm::Log2_32(LHSElts+1))-1); 722 else 723 EltMask = llvm::ConstantInt::get(MTy->getElementType(), 724 (1 << llvm::Log2_32(LHSElts))-1); 725 726 // Mask off the high bits of each shuffle index. 727 SmallVector<llvm::Constant *, 32> MaskV; 728 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) 729 MaskV.push_back(EltMask); 730 731 Value* MaskBits = llvm::ConstantVector::get(MaskV); 732 Mask = Builder.CreateAnd(Mask, MaskBits, "mask"); 733 734 // newv = undef 735 // mask = mask & maskbits 736 // for each elt 737 // n = extract mask i 738 // x = extract val n 739 // newv = insert newv, x, i 740 llvm::VectorType *RTy = llvm::VectorType::get(LTy->getElementType(), 741 MTy->getNumElements()); 742 Value* NewV = llvm::UndefValue::get(RTy); 743 for (unsigned i = 0, e = MTy->getNumElements(); i != e; ++i) { 744 Value *Indx = Builder.getInt32(i); 745 Indx = Builder.CreateExtractElement(Mask, Indx, "shuf_idx"); 746 Indx = Builder.CreateZExt(Indx, CGF.Int32Ty, "idx_zext"); 747 748 // Handle vec3 special since the index will be off by one for the RHS. 749 if ((LHSElts == 6) && (E->getNumSubExprs() == 3)) { 750 Value *cmpIndx, *newIndx; 751 cmpIndx = Builder.CreateICmpUGT(Indx, Builder.getInt32(3), 752 "cmp_shuf_idx"); 753 newIndx = Builder.CreateSub(Indx, Builder.getInt32(1), "shuf_idx_adj"); 754 Indx = Builder.CreateSelect(cmpIndx, newIndx, Indx, "sel_shuf_idx"); 755 } 756 Value *VExt = Builder.CreateExtractElement(LHS, Indx, "shuf_elt"); 757 NewV = Builder.CreateInsertElement(NewV, VExt, Indx, "shuf_ins"); 758 } 759 return NewV; 760 } 761 762 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 763 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 764 765 // Handle vec3 special since the index will be off by one for the RHS. 766 llvm::VectorType *VTy = cast<llvm::VectorType>(V1->getType()); 767 SmallVector<llvm::Constant*, 32> indices; 768 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 769 unsigned Idx = E->getShuffleMaskIdx(CGF.getContext(), i-2); 770 if (VTy->getNumElements() == 3 && Idx > 3) 771 Idx -= 1; 772 indices.push_back(Builder.getInt32(Idx)); 773 } 774 775 Value *SV = llvm::ConstantVector::get(indices); 776 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 777} 778Value *ScalarExprEmitter::VisitMemberExpr(MemberExpr *E) { 779 Expr::EvalResult Result; 780 if (E->Evaluate(Result, CGF.getContext()) && Result.Val.isInt()) { 781 if (E->isArrow()) 782 CGF.EmitScalarExpr(E->getBase()); 783 else 784 EmitLValue(E->getBase()); 785 return Builder.getInt(Result.Val.getInt()); 786 } 787 788 // Emit debug info for aggregate now, if it was delayed to reduce 789 // debug info size. 790 CGDebugInfo *DI = CGF.getDebugInfo(); 791 if (DI && CGF.CGM.getCodeGenOpts().LimitDebugInfo) { 792 QualType PQTy = E->getBase()->IgnoreParenImpCasts()->getType(); 793 if (const PointerType * PTy = dyn_cast<PointerType>(PQTy)) 794 if (FieldDecl *M = dyn_cast<FieldDecl>(E->getMemberDecl())) 795 DI->getOrCreateRecordType(PTy->getPointeeType(), 796 M->getParent()->getLocation()); 797 } 798 return EmitLoadOfLValue(E); 799} 800 801Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 802 TestAndClearIgnoreResultAssign(); 803 804 // Emit subscript expressions in rvalue context's. For most cases, this just 805 // loads the lvalue formed by the subscript expr. However, we have to be 806 // careful, because the base of a vector subscript is occasionally an rvalue, 807 // so we can't get it as an lvalue. 808 if (!E->getBase()->getType()->isVectorType()) 809 return EmitLoadOfLValue(E); 810 811 // Handle the vector case. The base must be a vector, the index must be an 812 // integer value. 813 Value *Base = Visit(E->getBase()); 814 Value *Idx = Visit(E->getIdx()); 815 bool IdxSigned = E->getIdx()->getType()->isSignedIntegerOrEnumerationType(); 816 Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vecidxcast"); 817 return Builder.CreateExtractElement(Base, Idx, "vecext"); 818} 819 820static llvm::Constant *getMaskElt(llvm::ShuffleVectorInst *SVI, unsigned Idx, 821 unsigned Off, llvm::Type *I32Ty) { 822 int MV = SVI->getMaskValue(Idx); 823 if (MV == -1) 824 return llvm::UndefValue::get(I32Ty); 825 return llvm::ConstantInt::get(I32Ty, Off+MV); 826} 827 828Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) { 829 bool Ignore = TestAndClearIgnoreResultAssign(); 830 (void)Ignore; 831 assert (Ignore == false && "init list ignored"); 832 unsigned NumInitElements = E->getNumInits(); 833 834 if (E->hadArrayRangeDesignator()) 835 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 836 837 llvm::VectorType *VType = 838 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 839 840 if (!VType) { 841 if (NumInitElements == 0) { 842 // C++11 value-initialization for the scalar. 843 return EmitNullValue(E->getType()); 844 } 845 // We have a scalar in braces. Just use the first element. 846 return Visit(E->getInit(0)); 847 } 848 849 unsigned ResElts = VType->getNumElements(); 850 851 // Loop over initializers collecting the Value for each, and remembering 852 // whether the source was swizzle (ExtVectorElementExpr). This will allow 853 // us to fold the shuffle for the swizzle into the shuffle for the vector 854 // initializer, since LLVM optimizers generally do not want to touch 855 // shuffles. 856 unsigned CurIdx = 0; 857 bool VIsUndefShuffle = false; 858 llvm::Value *V = llvm::UndefValue::get(VType); 859 for (unsigned i = 0; i != NumInitElements; ++i) { 860 Expr *IE = E->getInit(i); 861 Value *Init = Visit(IE); 862 SmallVector<llvm::Constant*, 16> Args; 863 864 llvm::VectorType *VVT = dyn_cast<llvm::VectorType>(Init->getType()); 865 866 // Handle scalar elements. If the scalar initializer is actually one 867 // element of a different vector of the same width, use shuffle instead of 868 // extract+insert. 869 if (!VVT) { 870 if (isa<ExtVectorElementExpr>(IE)) { 871 llvm::ExtractElementInst *EI = cast<llvm::ExtractElementInst>(Init); 872 873 if (EI->getVectorOperandType()->getNumElements() == ResElts) { 874 llvm::ConstantInt *C = cast<llvm::ConstantInt>(EI->getIndexOperand()); 875 Value *LHS = 0, *RHS = 0; 876 if (CurIdx == 0) { 877 // insert into undef -> shuffle (src, undef) 878 Args.push_back(C); 879 for (unsigned j = 1; j != ResElts; ++j) 880 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 881 882 LHS = EI->getVectorOperand(); 883 RHS = V; 884 VIsUndefShuffle = true; 885 } else if (VIsUndefShuffle) { 886 // insert into undefshuffle && size match -> shuffle (v, src) 887 llvm::ShuffleVectorInst *SVV = cast<llvm::ShuffleVectorInst>(V); 888 for (unsigned j = 0; j != CurIdx; ++j) 889 Args.push_back(getMaskElt(SVV, j, 0, CGF.Int32Ty)); 890 Args.push_back(Builder.getInt32(ResElts + C->getZExtValue())); 891 for (unsigned j = CurIdx + 1; j != ResElts; ++j) 892 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 893 894 LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 895 RHS = EI->getVectorOperand(); 896 VIsUndefShuffle = false; 897 } 898 if (!Args.empty()) { 899 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 900 V = Builder.CreateShuffleVector(LHS, RHS, Mask); 901 ++CurIdx; 902 continue; 903 } 904 } 905 } 906 V = Builder.CreateInsertElement(V, Init, Builder.getInt32(CurIdx), 907 "vecinit"); 908 VIsUndefShuffle = false; 909 ++CurIdx; 910 continue; 911 } 912 913 unsigned InitElts = VVT->getNumElements(); 914 915 // If the initializer is an ExtVecEltExpr (a swizzle), and the swizzle's 916 // input is the same width as the vector being constructed, generate an 917 // optimized shuffle of the swizzle input into the result. 918 unsigned Offset = (CurIdx == 0) ? 0 : ResElts; 919 if (isa<ExtVectorElementExpr>(IE)) { 920 llvm::ShuffleVectorInst *SVI = cast<llvm::ShuffleVectorInst>(Init); 921 Value *SVOp = SVI->getOperand(0); 922 llvm::VectorType *OpTy = cast<llvm::VectorType>(SVOp->getType()); 923 924 if (OpTy->getNumElements() == ResElts) { 925 for (unsigned j = 0; j != CurIdx; ++j) { 926 // If the current vector initializer is a shuffle with undef, merge 927 // this shuffle directly into it. 928 if (VIsUndefShuffle) { 929 Args.push_back(getMaskElt(cast<llvm::ShuffleVectorInst>(V), j, 0, 930 CGF.Int32Ty)); 931 } else { 932 Args.push_back(Builder.getInt32(j)); 933 } 934 } 935 for (unsigned j = 0, je = InitElts; j != je; ++j) 936 Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty)); 937 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 938 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 939 940 if (VIsUndefShuffle) 941 V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0); 942 943 Init = SVOp; 944 } 945 } 946 947 // Extend init to result vector length, and then shuffle its contribution 948 // to the vector initializer into V. 949 if (Args.empty()) { 950 for (unsigned j = 0; j != InitElts; ++j) 951 Args.push_back(Builder.getInt32(j)); 952 for (unsigned j = InitElts; j != ResElts; ++j) 953 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 954 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 955 Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT), 956 Mask, "vext"); 957 958 Args.clear(); 959 for (unsigned j = 0; j != CurIdx; ++j) 960 Args.push_back(Builder.getInt32(j)); 961 for (unsigned j = 0; j != InitElts; ++j) 962 Args.push_back(Builder.getInt32(j+Offset)); 963 for (unsigned j = CurIdx + InitElts; j != ResElts; ++j) 964 Args.push_back(llvm::UndefValue::get(CGF.Int32Ty)); 965 } 966 967 // If V is undef, make sure it ends up on the RHS of the shuffle to aid 968 // merging subsequent shuffles into this one. 969 if (CurIdx == 0) 970 std::swap(V, Init); 971 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 972 V = Builder.CreateShuffleVector(V, Init, Mask, "vecinit"); 973 VIsUndefShuffle = isa<llvm::UndefValue>(Init); 974 CurIdx += InitElts; 975 } 976 977 // FIXME: evaluate codegen vs. shuffling against constant null vector. 978 // Emit remaining default initializers. 979 llvm::Type *EltTy = VType->getElementType(); 980 981 // Emit remaining default initializers 982 for (/* Do not initialize i*/; CurIdx < ResElts; ++CurIdx) { 983 Value *Idx = Builder.getInt32(CurIdx); 984 llvm::Value *Init = llvm::Constant::getNullValue(EltTy); 985 V = Builder.CreateInsertElement(V, Init, Idx, "vecinit"); 986 } 987 return V; 988} 989 990static bool ShouldNullCheckClassCastValue(const CastExpr *CE) { 991 const Expr *E = CE->getSubExpr(); 992 993 if (CE->getCastKind() == CK_UncheckedDerivedToBase) 994 return false; 995 996 if (isa<CXXThisExpr>(E)) { 997 // We always assume that 'this' is never null. 998 return false; 999 } 1000 1001 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(CE)) { 1002 // And that glvalue casts are never null. 1003 if (ICE->getValueKind() != VK_RValue) 1004 return false; 1005 } 1006 1007 return true; 1008} 1009 1010// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 1011// have to handle a more broad range of conversions than explicit casts, as they 1012// handle things like function to ptr-to-function decay etc. 1013Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) { 1014 Expr *E = CE->getSubExpr(); 1015 QualType DestTy = CE->getType(); 1016 CastKind Kind = CE->getCastKind(); 1017 1018 if (!DestTy->isVoidType()) 1019 TestAndClearIgnoreResultAssign(); 1020 1021 // Since almost all cast kinds apply to scalars, this switch doesn't have 1022 // a default case, so the compiler will warn on a missing case. The cases 1023 // are in the same order as in the CastKind enum. 1024 switch (Kind) { 1025 case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!"); 1026 1027 case CK_LValueBitCast: 1028 case CK_ObjCObjectLValueCast: { 1029 Value *V = EmitLValue(E).getAddress(); 1030 V = Builder.CreateBitCast(V, 1031 ConvertType(CGF.getContext().getPointerType(DestTy))); 1032 return EmitLoadOfLValue(CGF.MakeAddrLValue(V, DestTy)); 1033 } 1034 1035 case CK_CPointerToObjCPointerCast: 1036 case CK_BlockPointerToObjCPointerCast: 1037 case CK_AnyPointerToBlockPointerCast: 1038 case CK_BitCast: { 1039 Value *Src = Visit(const_cast<Expr*>(E)); 1040 return Builder.CreateBitCast(Src, ConvertType(DestTy)); 1041 } 1042 case CK_NoOp: 1043 case CK_UserDefinedConversion: 1044 return Visit(const_cast<Expr*>(E)); 1045 1046 case CK_BaseToDerived: { 1047 const CXXRecordDecl *DerivedClassDecl = 1048 DestTy->getCXXRecordDeclForPointerType(); 1049 1050 return CGF.GetAddressOfDerivedClass(Visit(E), DerivedClassDecl, 1051 CE->path_begin(), CE->path_end(), 1052 ShouldNullCheckClassCastValue(CE)); 1053 } 1054 case CK_UncheckedDerivedToBase: 1055 case CK_DerivedToBase: { 1056 const RecordType *DerivedClassTy = 1057 E->getType()->getAs<PointerType>()->getPointeeType()->getAs<RecordType>(); 1058 CXXRecordDecl *DerivedClassDecl = 1059 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 1060 1061 return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl, 1062 CE->path_begin(), CE->path_end(), 1063 ShouldNullCheckClassCastValue(CE)); 1064 } 1065 case CK_Dynamic: { 1066 Value *V = Visit(const_cast<Expr*>(E)); 1067 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE); 1068 return CGF.EmitDynamicCast(V, DCE); 1069 } 1070 1071 case CK_ArrayToPointerDecay: { 1072 assert(E->getType()->isArrayType() && 1073 "Array to pointer decay must have array source type!"); 1074 1075 Value *V = EmitLValue(E).getAddress(); // Bitfields can't be arrays. 1076 1077 // Note that VLA pointers are always decayed, so we don't need to do 1078 // anything here. 1079 if (!E->getType()->isVariableArrayType()) { 1080 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 1081 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 1082 ->getElementType()) && 1083 "Expected pointer to array"); 1084 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 1085 } 1086 1087 // Make sure the array decay ends up being the right type. This matters if 1088 // the array type was of an incomplete type. 1089 return CGF.Builder.CreateBitCast(V, ConvertType(CE->getType())); 1090 } 1091 case CK_FunctionToPointerDecay: 1092 return EmitLValue(E).getAddress(); 1093 1094 case CK_NullToPointer: 1095 if (MustVisitNullValue(E)) 1096 (void) Visit(E); 1097 1098 return llvm::ConstantPointerNull::get( 1099 cast<llvm::PointerType>(ConvertType(DestTy))); 1100 1101 case CK_NullToMemberPointer: { 1102 if (MustVisitNullValue(E)) 1103 (void) Visit(E); 1104 1105 const MemberPointerType *MPT = CE->getType()->getAs<MemberPointerType>(); 1106 return CGF.CGM.getCXXABI().EmitNullMemberPointer(MPT); 1107 } 1108 1109 case CK_BaseToDerivedMemberPointer: 1110 case CK_DerivedToBaseMemberPointer: { 1111 Value *Src = Visit(E); 1112 1113 // Note that the AST doesn't distinguish between checked and 1114 // unchecked member pointer conversions, so we always have to 1115 // implement checked conversions here. This is inefficient when 1116 // actual control flow may be required in order to perform the 1117 // check, which it is for data member pointers (but not member 1118 // function pointers on Itanium and ARM). 1119 return CGF.CGM.getCXXABI().EmitMemberPointerConversion(CGF, CE, Src); 1120 } 1121 1122 case CK_ARCProduceObject: 1123 return CGF.EmitARCRetainScalarExpr(E); 1124 case CK_ARCConsumeObject: 1125 return CGF.EmitObjCConsumeObject(E->getType(), Visit(E)); 1126 case CK_ARCReclaimReturnedObject: { 1127 llvm::Value *value = Visit(E); 1128 value = CGF.EmitARCRetainAutoreleasedReturnValue(value); 1129 return CGF.EmitObjCConsumeObject(E->getType(), value); 1130 } 1131 case CK_ARCExtendBlockObject: 1132 return CGF.EmitARCExtendBlockObject(E); 1133 1134 case CK_FloatingRealToComplex: 1135 case CK_FloatingComplexCast: 1136 case CK_IntegralRealToComplex: 1137 case CK_IntegralComplexCast: 1138 case CK_IntegralComplexToFloatingComplex: 1139 case CK_FloatingComplexToIntegralComplex: 1140 case CK_ConstructorConversion: 1141 case CK_ToUnion: 1142 llvm_unreachable("scalar cast to non-scalar value"); 1143 break; 1144 1145 case CK_GetObjCProperty: { 1146 assert(CGF.getContext().hasSameUnqualifiedType(E->getType(), DestTy)); 1147 assert(E->isGLValue() && E->getObjectKind() == OK_ObjCProperty && 1148 "CK_GetObjCProperty for non-lvalue or non-ObjCProperty"); 1149 RValue RV = CGF.EmitLoadOfLValue(CGF.EmitLValue(E)); 1150 return RV.getScalarVal(); 1151 } 1152 1153 case CK_LValueToRValue: 1154 assert(CGF.getContext().hasSameUnqualifiedType(E->getType(), DestTy)); 1155 assert(E->isGLValue() && "lvalue-to-rvalue applied to r-value!"); 1156 return Visit(const_cast<Expr*>(E)); 1157 1158 case CK_IntegralToPointer: { 1159 Value *Src = Visit(const_cast<Expr*>(E)); 1160 1161 // First, convert to the correct width so that we control the kind of 1162 // extension. 1163 llvm::Type *MiddleTy = CGF.IntPtrTy; 1164 bool InputSigned = E->getType()->isSignedIntegerOrEnumerationType(); 1165 llvm::Value* IntResult = 1166 Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); 1167 1168 return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy)); 1169 } 1170 case CK_PointerToIntegral: 1171 assert(!DestTy->isBooleanType() && "bool should use PointerToBool"); 1172 return Builder.CreatePtrToInt(Visit(E), ConvertType(DestTy)); 1173 1174 case CK_ToVoid: { 1175 CGF.EmitIgnoredExpr(E); 1176 return 0; 1177 } 1178 case CK_VectorSplat: { 1179 llvm::Type *DstTy = ConvertType(DestTy); 1180 Value *Elt = Visit(const_cast<Expr*>(E)); 1181 1182 // Insert the element in element zero of an undef vector 1183 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 1184 llvm::Value *Idx = Builder.getInt32(0); 1185 UnV = Builder.CreateInsertElement(UnV, Elt, Idx); 1186 1187 // Splat the element across to all elements 1188 SmallVector<llvm::Constant*, 16> Args; 1189 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 1190 llvm::Constant *Zero = Builder.getInt32(0); 1191 for (unsigned i = 0; i < NumElements; i++) 1192 Args.push_back(Zero); 1193 1194 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 1195 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 1196 return Yay; 1197 } 1198 1199 case CK_IntegralCast: 1200 case CK_IntegralToFloating: 1201 case CK_FloatingToIntegral: 1202 case CK_FloatingCast: 1203 return EmitScalarConversion(Visit(E), E->getType(), DestTy); 1204 1205 case CK_IntegralToBoolean: 1206 return EmitIntToBoolConversion(Visit(E)); 1207 case CK_PointerToBoolean: 1208 return EmitPointerToBoolConversion(Visit(E)); 1209 case CK_FloatingToBoolean: 1210 return EmitFloatToBoolConversion(Visit(E)); 1211 case CK_MemberPointerToBoolean: { 1212 llvm::Value *MemPtr = Visit(E); 1213 const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>(); 1214 return CGF.CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF, MemPtr, MPT); 1215 } 1216 1217 case CK_FloatingComplexToReal: 1218 case CK_IntegralComplexToReal: 1219 return CGF.EmitComplexExpr(E, false, true).first; 1220 1221 case CK_FloatingComplexToBoolean: 1222 case CK_IntegralComplexToBoolean: { 1223 CodeGenFunction::ComplexPairTy V = CGF.EmitComplexExpr(E); 1224 1225 // TODO: kill this function off, inline appropriate case here 1226 return EmitComplexToScalarConversion(V, E->getType(), DestTy); 1227 } 1228 1229 } 1230 1231 llvm_unreachable("unknown scalar cast"); 1232 return 0; 1233} 1234 1235Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 1236 CodeGenFunction::StmtExprEvaluation eval(CGF); 1237 return CGF.EmitCompoundStmt(*E->getSubStmt(), !E->getType()->isVoidType()) 1238 .getScalarVal(); 1239} 1240 1241Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 1242 LValue LV = CGF.EmitBlockDeclRefLValue(E); 1243 return CGF.EmitLoadOfLValue(LV).getScalarVal(); 1244} 1245 1246//===----------------------------------------------------------------------===// 1247// Unary Operators 1248//===----------------------------------------------------------------------===// 1249 1250llvm::Value *ScalarExprEmitter:: 1251EmitAddConsiderOverflowBehavior(const UnaryOperator *E, 1252 llvm::Value *InVal, 1253 llvm::Value *NextVal, bool IsInc) { 1254 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1255 case LangOptions::SOB_Undefined: 1256 return Builder.CreateNSWAdd(InVal, NextVal, IsInc ? "inc" : "dec"); 1257 break; 1258 case LangOptions::SOB_Defined: 1259 return Builder.CreateAdd(InVal, NextVal, IsInc ? "inc" : "dec"); 1260 break; 1261 case LangOptions::SOB_Trapping: 1262 BinOpInfo BinOp; 1263 BinOp.LHS = InVal; 1264 BinOp.RHS = NextVal; 1265 BinOp.Ty = E->getType(); 1266 BinOp.Opcode = BO_Add; 1267 BinOp.E = E; 1268 return EmitOverflowCheckedBinOp(BinOp); 1269 } 1270 llvm_unreachable("Unknown SignedOverflowBehaviorTy"); 1271} 1272 1273llvm::Value * 1274ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 1275 bool isInc, bool isPre) { 1276 1277 QualType type = E->getSubExpr()->getType(); 1278 llvm::Value *value = EmitLoadOfLValue(LV); 1279 llvm::Value *input = value; 1280 1281 int amount = (isInc ? 1 : -1); 1282 1283 // Special case of integer increment that we have to check first: bool++. 1284 // Due to promotion rules, we get: 1285 // bool++ -> bool = bool + 1 1286 // -> bool = (int)bool + 1 1287 // -> bool = ((int)bool + 1 != 0) 1288 // An interesting aspect of this is that increment is always true. 1289 // Decrement does not have this property. 1290 if (isInc && type->isBooleanType()) { 1291 value = Builder.getTrue(); 1292 1293 // Most common case by far: integer increment. 1294 } else if (type->isIntegerType()) { 1295 1296 llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount); 1297 1298 // Note that signed integer inc/dec with width less than int can't 1299 // overflow because of promotion rules; we're just eliding a few steps here. 1300 if (type->isSignedIntegerOrEnumerationType() && 1301 value->getType()->getPrimitiveSizeInBits() >= 1302 CGF.IntTy->getBitWidth()) 1303 value = EmitAddConsiderOverflowBehavior(E, value, amt, isInc); 1304 else 1305 value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec"); 1306 1307 // Next most common: pointer increment. 1308 } else if (const PointerType *ptr = type->getAs<PointerType>()) { 1309 QualType type = ptr->getPointeeType(); 1310 1311 // VLA types don't have constant size. 1312 if (const VariableArrayType *vla 1313 = CGF.getContext().getAsVariableArrayType(type)) { 1314 llvm::Value *numElts = CGF.getVLASize(vla).first; 1315 if (!isInc) numElts = Builder.CreateNSWNeg(numElts, "vla.negsize"); 1316 if (CGF.getContext().getLangOptions().isSignedOverflowDefined()) 1317 value = Builder.CreateGEP(value, numElts, "vla.inc"); 1318 else 1319 value = Builder.CreateInBoundsGEP(value, numElts, "vla.inc"); 1320 1321 // Arithmetic on function pointers (!) is just +-1. 1322 } else if (type->isFunctionType()) { 1323 llvm::Value *amt = Builder.getInt32(amount); 1324 1325 value = CGF.EmitCastToVoidPtr(value); 1326 if (CGF.getContext().getLangOptions().isSignedOverflowDefined()) 1327 value = Builder.CreateGEP(value, amt, "incdec.funcptr"); 1328 else 1329 value = Builder.CreateInBoundsGEP(value, amt, "incdec.funcptr"); 1330 value = Builder.CreateBitCast(value, input->getType()); 1331 1332 // For everything else, we can just do a simple increment. 1333 } else { 1334 llvm::Value *amt = Builder.getInt32(amount); 1335 if (CGF.getContext().getLangOptions().isSignedOverflowDefined()) 1336 value = Builder.CreateGEP(value, amt, "incdec.ptr"); 1337 else 1338 value = Builder.CreateInBoundsGEP(value, amt, "incdec.ptr"); 1339 } 1340 1341 // Vector increment/decrement. 1342 } else if (type->isVectorType()) { 1343 if (type->hasIntegerRepresentation()) { 1344 llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount); 1345 1346 value = Builder.CreateAdd(value, amt, isInc ? "inc" : "dec"); 1347 } else { 1348 value = Builder.CreateFAdd( 1349 value, 1350 llvm::ConstantFP::get(value->getType(), amount), 1351 isInc ? "inc" : "dec"); 1352 } 1353 1354 // Floating point. 1355 } else if (type->isRealFloatingType()) { 1356 // Add the inc/dec to the real part. 1357 llvm::Value *amt; 1358 if (value->getType()->isFloatTy()) 1359 amt = llvm::ConstantFP::get(VMContext, 1360 llvm::APFloat(static_cast<float>(amount))); 1361 else if (value->getType()->isDoubleTy()) 1362 amt = llvm::ConstantFP::get(VMContext, 1363 llvm::APFloat(static_cast<double>(amount))); 1364 else { 1365 llvm::APFloat F(static_cast<float>(amount)); 1366 bool ignored; 1367 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, 1368 &ignored); 1369 amt = llvm::ConstantFP::get(VMContext, F); 1370 } 1371 value = Builder.CreateFAdd(value, amt, isInc ? "inc" : "dec"); 1372 1373 // Objective-C pointer types. 1374 } else { 1375 const ObjCObjectPointerType *OPT = type->castAs<ObjCObjectPointerType>(); 1376 value = CGF.EmitCastToVoidPtr(value); 1377 1378 CharUnits size = CGF.getContext().getTypeSizeInChars(OPT->getObjectType()); 1379 if (!isInc) size = -size; 1380 llvm::Value *sizeValue = 1381 llvm::ConstantInt::get(CGF.SizeTy, size.getQuantity()); 1382 1383 if (CGF.getContext().getLangOptions().isSignedOverflowDefined()) 1384 value = Builder.CreateGEP(value, sizeValue, "incdec.objptr"); 1385 else 1386 value = Builder.CreateInBoundsGEP(value, sizeValue, "incdec.objptr"); 1387 value = Builder.CreateBitCast(value, input->getType()); 1388 } 1389 1390 // Store the updated result through the lvalue. 1391 if (LV.isBitField()) 1392 CGF.EmitStoreThroughBitfieldLValue(RValue::get(value), LV, &value); 1393 else 1394 CGF.EmitStoreThroughLValue(RValue::get(value), LV); 1395 1396 // If this is a postinc, return the value read from memory, otherwise use the 1397 // updated value. 1398 return isPre ? value : input; 1399} 1400 1401 1402 1403Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 1404 TestAndClearIgnoreResultAssign(); 1405 // Emit unary minus with EmitSub so we handle overflow cases etc. 1406 BinOpInfo BinOp; 1407 BinOp.RHS = Visit(E->getSubExpr()); 1408 1409 if (BinOp.RHS->getType()->isFPOrFPVectorTy()) 1410 BinOp.LHS = llvm::ConstantFP::getZeroValueForNegation(BinOp.RHS->getType()); 1411 else 1412 BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType()); 1413 BinOp.Ty = E->getType(); 1414 BinOp.Opcode = BO_Sub; 1415 BinOp.E = E; 1416 return EmitSub(BinOp); 1417} 1418 1419Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 1420 TestAndClearIgnoreResultAssign(); 1421 Value *Op = Visit(E->getSubExpr()); 1422 return Builder.CreateNot(Op, "neg"); 1423} 1424 1425Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 1426 // Compare operand to zero. 1427 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 1428 1429 // Invert value. 1430 // TODO: Could dynamically modify easy computations here. For example, if 1431 // the operand is an icmp ne, turn into icmp eq. 1432 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 1433 1434 // ZExt result to the expr type. 1435 return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); 1436} 1437 1438Value *ScalarExprEmitter::VisitOffsetOfExpr(OffsetOfExpr *E) { 1439 // Try folding the offsetof to a constant. 1440 Expr::EvalResult EvalResult; 1441 if (E->Evaluate(EvalResult, CGF.getContext())) 1442 return Builder.getInt(EvalResult.Val.getInt()); 1443 1444 // Loop over the components of the offsetof to compute the value. 1445 unsigned n = E->getNumComponents(); 1446 llvm::Type* ResultType = ConvertType(E->getType()); 1447 llvm::Value* Result = llvm::Constant::getNullValue(ResultType); 1448 QualType CurrentType = E->getTypeSourceInfo()->getType(); 1449 for (unsigned i = 0; i != n; ++i) { 1450 OffsetOfExpr::OffsetOfNode ON = E->getComponent(i); 1451 llvm::Value *Offset = 0; 1452 switch (ON.getKind()) { 1453 case OffsetOfExpr::OffsetOfNode::Array: { 1454 // Compute the index 1455 Expr *IdxExpr = E->getIndexExpr(ON.getArrayExprIndex()); 1456 llvm::Value* Idx = CGF.EmitScalarExpr(IdxExpr); 1457 bool IdxSigned = IdxExpr->getType()->isSignedIntegerOrEnumerationType(); 1458 Idx = Builder.CreateIntCast(Idx, ResultType, IdxSigned, "conv"); 1459 1460 // Save the element type 1461 CurrentType = 1462 CGF.getContext().getAsArrayType(CurrentType)->getElementType(); 1463 1464 // Compute the element size 1465 llvm::Value* ElemSize = llvm::ConstantInt::get(ResultType, 1466 CGF.getContext().getTypeSizeInChars(CurrentType).getQuantity()); 1467 1468 // Multiply out to compute the result 1469 Offset = Builder.CreateMul(Idx, ElemSize); 1470 break; 1471 } 1472 1473 case OffsetOfExpr::OffsetOfNode::Field: { 1474 FieldDecl *MemberDecl = ON.getField(); 1475 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1476 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1477 1478 // Compute the index of the field in its parent. 1479 unsigned i = 0; 1480 // FIXME: It would be nice if we didn't have to loop here! 1481 for (RecordDecl::field_iterator Field = RD->field_begin(), 1482 FieldEnd = RD->field_end(); 1483 Field != FieldEnd; (void)++Field, ++i) { 1484 if (*Field == MemberDecl) 1485 break; 1486 } 1487 assert(i < RL.getFieldCount() && "offsetof field in wrong type"); 1488 1489 // Compute the offset to the field 1490 int64_t OffsetInt = RL.getFieldOffset(i) / 1491 CGF.getContext().getCharWidth(); 1492 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1493 1494 // Save the element type. 1495 CurrentType = MemberDecl->getType(); 1496 break; 1497 } 1498 1499 case OffsetOfExpr::OffsetOfNode::Identifier: 1500 llvm_unreachable("dependent __builtin_offsetof"); 1501 1502 case OffsetOfExpr::OffsetOfNode::Base: { 1503 if (ON.getBase()->isVirtual()) { 1504 CGF.ErrorUnsupported(E, "virtual base in offsetof"); 1505 continue; 1506 } 1507 1508 RecordDecl *RD = CurrentType->getAs<RecordType>()->getDecl(); 1509 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 1510 1511 // Save the element type. 1512 CurrentType = ON.getBase()->getType(); 1513 1514 // Compute the offset to the base. 1515 const RecordType *BaseRT = CurrentType->getAs<RecordType>(); 1516 CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl()); 1517 int64_t OffsetInt = RL.getBaseClassOffsetInBits(BaseRD) / 1518 CGF.getContext().getCharWidth(); 1519 Offset = llvm::ConstantInt::get(ResultType, OffsetInt); 1520 break; 1521 } 1522 } 1523 Result = Builder.CreateAdd(Result, Offset); 1524 } 1525 return Result; 1526} 1527 1528/// VisitUnaryExprOrTypeTraitExpr - Return the size or alignment of the type of 1529/// argument of the sizeof expression as an integer. 1530Value * 1531ScalarExprEmitter::VisitUnaryExprOrTypeTraitExpr( 1532 const UnaryExprOrTypeTraitExpr *E) { 1533 QualType TypeToSize = E->getTypeOfArgument(); 1534 if (E->getKind() == UETT_SizeOf) { 1535 if (const VariableArrayType *VAT = 1536 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 1537 if (E->isArgumentType()) { 1538 // sizeof(type) - make sure to emit the VLA size. 1539 CGF.EmitVariablyModifiedType(TypeToSize); 1540 } else { 1541 // C99 6.5.3.4p2: If the argument is an expression of type 1542 // VLA, it is evaluated. 1543 CGF.EmitIgnoredExpr(E->getArgumentExpr()); 1544 } 1545 1546 QualType eltType; 1547 llvm::Value *numElts; 1548 llvm::tie(numElts, eltType) = CGF.getVLASize(VAT); 1549 1550 llvm::Value *size = numElts; 1551 1552 // Scale the number of non-VLA elements by the non-VLA element size. 1553 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType); 1554 if (!eltSize.isOne()) 1555 size = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), numElts); 1556 1557 return size; 1558 } 1559 } 1560 1561 // If this isn't sizeof(vla), the result must be constant; use the constant 1562 // folding logic so we don't have to duplicate it here. 1563 Expr::EvalResult Result; 1564 E->Evaluate(Result, CGF.getContext()); 1565 return Builder.getInt(Result.Val.getInt()); 1566} 1567 1568Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 1569 Expr *Op = E->getSubExpr(); 1570 if (Op->getType()->isAnyComplexType()) { 1571 // If it's an l-value, load through the appropriate subobject l-value. 1572 // Note that we have to ask E because Op might be an l-value that 1573 // this won't work for, e.g. an Obj-C property. 1574 if (E->isGLValue()) 1575 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E)).getScalarVal(); 1576 1577 // Otherwise, calculate and project. 1578 return CGF.EmitComplexExpr(Op, false, true).first; 1579 } 1580 1581 return Visit(Op); 1582} 1583 1584Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 1585 Expr *Op = E->getSubExpr(); 1586 if (Op->getType()->isAnyComplexType()) { 1587 // If it's an l-value, load through the appropriate subobject l-value. 1588 // Note that we have to ask E because Op might be an l-value that 1589 // this won't work for, e.g. an Obj-C property. 1590 if (Op->isGLValue()) 1591 return CGF.EmitLoadOfLValue(CGF.EmitLValue(E)).getScalarVal(); 1592 1593 // Otherwise, calculate and project. 1594 return CGF.EmitComplexExpr(Op, true, false).second; 1595 } 1596 1597 // __imag on a scalar returns zero. Emit the subexpr to ensure side 1598 // effects are evaluated, but not the actual value. 1599 CGF.EmitScalarExpr(Op, true); 1600 return llvm::Constant::getNullValue(ConvertType(E->getType())); 1601} 1602 1603//===----------------------------------------------------------------------===// 1604// Binary Operators 1605//===----------------------------------------------------------------------===// 1606 1607BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 1608 TestAndClearIgnoreResultAssign(); 1609 BinOpInfo Result; 1610 Result.LHS = Visit(E->getLHS()); 1611 Result.RHS = Visit(E->getRHS()); 1612 Result.Ty = E->getType(); 1613 Result.Opcode = E->getOpcode(); 1614 Result.E = E; 1615 return Result; 1616} 1617 1618LValue ScalarExprEmitter::EmitCompoundAssignLValue( 1619 const CompoundAssignOperator *E, 1620 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &), 1621 Value *&Result) { 1622 QualType LHSTy = E->getLHS()->getType(); 1623 BinOpInfo OpInfo; 1624 1625 if (E->getComputationResultType()->isAnyComplexType()) { 1626 // This needs to go through the complex expression emitter, but it's a tad 1627 // complicated to do that... I'm leaving it out for now. (Note that we do 1628 // actually need the imaginary part of the RHS for multiplication and 1629 // division.) 1630 CGF.ErrorUnsupported(E, "complex compound assignment"); 1631 Result = llvm::UndefValue::get(CGF.ConvertType(E->getType())); 1632 return LValue(); 1633 } 1634 1635 // Emit the RHS first. __block variables need to have the rhs evaluated 1636 // first, plus this should improve codegen a little. 1637 OpInfo.RHS = Visit(E->getRHS()); 1638 OpInfo.Ty = E->getComputationResultType(); 1639 OpInfo.Opcode = E->getOpcode(); 1640 OpInfo.E = E; 1641 // Load/convert the LHS. 1642 LValue LHSLV = EmitCheckedLValue(E->getLHS()); 1643 OpInfo.LHS = EmitLoadOfLValue(LHSLV); 1644 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, 1645 E->getComputationLHSType()); 1646 1647 // Expand the binary operator. 1648 Result = (this->*Func)(OpInfo); 1649 1650 // Convert the result back to the LHS type. 1651 Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); 1652 1653 // Store the result value into the LHS lvalue. Bit-fields are handled 1654 // specially because the result is altered by the store, i.e., [C99 6.5.16p1] 1655 // 'An assignment expression has the value of the left operand after the 1656 // assignment...'. 1657 if (LHSLV.isBitField()) 1658 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, &Result); 1659 else 1660 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV); 1661 1662 return LHSLV; 1663} 1664 1665Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 1666 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 1667 bool Ignore = TestAndClearIgnoreResultAssign(); 1668 Value *RHS; 1669 LValue LHS = EmitCompoundAssignLValue(E, Func, RHS); 1670 1671 // If the result is clearly ignored, return now. 1672 if (Ignore) 1673 return 0; 1674 1675 // The result of an assignment in C is the assigned r-value. 1676 if (!CGF.getContext().getLangOptions().CPlusPlus) 1677 return RHS; 1678 1679 // Objective-C property assignment never reloads the value following a store. 1680 if (LHS.isPropertyRef()) 1681 return RHS; 1682 1683 // If the lvalue is non-volatile, return the computed value of the assignment. 1684 if (!LHS.isVolatileQualified()) 1685 return RHS; 1686 1687 // Otherwise, reload the value. 1688 return EmitLoadOfLValue(LHS); 1689} 1690 1691void ScalarExprEmitter::EmitUndefinedBehaviorIntegerDivAndRemCheck( 1692 const BinOpInfo &Ops, 1693 llvm::Value *Zero, bool isDiv) { 1694 llvm::Function::iterator insertPt = Builder.GetInsertBlock(); 1695 llvm::BasicBlock *contBB = 1696 CGF.createBasicBlock(isDiv ? "div.cont" : "rem.cont", CGF.CurFn, 1697 llvm::next(insertPt)); 1698 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); 1699 1700 llvm::IntegerType *Ty = cast<llvm::IntegerType>(Zero->getType()); 1701 1702 if (Ops.Ty->hasSignedIntegerRepresentation()) { 1703 llvm::Value *IntMin = 1704 Builder.getInt(llvm::APInt::getSignedMinValue(Ty->getBitWidth())); 1705 llvm::Value *NegOne = llvm::ConstantInt::get(Ty, -1ULL); 1706 1707 llvm::Value *Cond1 = Builder.CreateICmpEQ(Ops.RHS, Zero); 1708 llvm::Value *LHSCmp = Builder.CreateICmpEQ(Ops.LHS, IntMin); 1709 llvm::Value *RHSCmp = Builder.CreateICmpEQ(Ops.RHS, NegOne); 1710 llvm::Value *Cond2 = Builder.CreateAnd(LHSCmp, RHSCmp, "and"); 1711 Builder.CreateCondBr(Builder.CreateOr(Cond1, Cond2, "or"), 1712 overflowBB, contBB); 1713 } else { 1714 CGF.Builder.CreateCondBr(Builder.CreateICmpEQ(Ops.RHS, Zero), 1715 overflowBB, contBB); 1716 } 1717 EmitOverflowBB(overflowBB); 1718 Builder.SetInsertPoint(contBB); 1719} 1720 1721Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 1722 if (isTrapvOverflowBehavior()) { 1723 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 1724 1725 if (Ops.Ty->isIntegerType()) 1726 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, true); 1727 else if (Ops.Ty->isRealFloatingType()) { 1728 llvm::Function::iterator insertPt = Builder.GetInsertBlock(); 1729 llvm::BasicBlock *DivCont = CGF.createBasicBlock("div.cont", CGF.CurFn, 1730 llvm::next(insertPt)); 1731 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", 1732 CGF.CurFn); 1733 CGF.Builder.CreateCondBr(Builder.CreateFCmpOEQ(Ops.RHS, Zero), 1734 overflowBB, DivCont); 1735 EmitOverflowBB(overflowBB); 1736 Builder.SetInsertPoint(DivCont); 1737 } 1738 } 1739 if (Ops.LHS->getType()->isFPOrFPVectorTy()) 1740 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 1741 else if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1742 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 1743 else 1744 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 1745} 1746 1747Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 1748 // Rem in C can't be a floating point type: C99 6.5.5p2. 1749 if (isTrapvOverflowBehavior()) { 1750 llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty)); 1751 1752 if (Ops.Ty->isIntegerType()) 1753 EmitUndefinedBehaviorIntegerDivAndRemCheck(Ops, Zero, false); 1754 } 1755 1756 if (Ops.Ty->hasUnsignedIntegerRepresentation()) 1757 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 1758 else 1759 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 1760} 1761 1762Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { 1763 unsigned IID; 1764 unsigned OpID = 0; 1765 1766 switch (Ops.Opcode) { 1767 case BO_Add: 1768 case BO_AddAssign: 1769 OpID = 1; 1770 IID = llvm::Intrinsic::sadd_with_overflow; 1771 break; 1772 case BO_Sub: 1773 case BO_SubAssign: 1774 OpID = 2; 1775 IID = llvm::Intrinsic::ssub_with_overflow; 1776 break; 1777 case BO_Mul: 1778 case BO_MulAssign: 1779 OpID = 3; 1780 IID = llvm::Intrinsic::smul_with_overflow; 1781 break; 1782 default: 1783 llvm_unreachable("Unsupported operation for overflow detection"); 1784 IID = 0; 1785 } 1786 OpID <<= 1; 1787 OpID |= 1; 1788 1789 llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); 1790 1791 llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, opTy); 1792 1793 Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); 1794 Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); 1795 Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); 1796 1797 // Branch in case of overflow. 1798 llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); 1799 llvm::Function::iterator insertPt = initialBB; 1800 llvm::BasicBlock *continueBB = CGF.createBasicBlock("nooverflow", CGF.CurFn, 1801 llvm::next(insertPt)); 1802 llvm::BasicBlock *overflowBB = CGF.createBasicBlock("overflow", CGF.CurFn); 1803 1804 Builder.CreateCondBr(overflow, overflowBB, continueBB); 1805 1806 // Handle overflow with llvm.trap. 1807 const std::string *handlerName = 1808 &CGF.getContext().getLangOptions().OverflowHandler; 1809 if (handlerName->empty()) { 1810 EmitOverflowBB(overflowBB); 1811 Builder.SetInsertPoint(continueBB); 1812 return result; 1813 } 1814 1815 // If an overflow handler is set, then we want to call it and then use its 1816 // result, if it returns. 1817 Builder.SetInsertPoint(overflowBB); 1818 1819 // Get the overflow handler. 1820 llvm::Type *Int8Ty = llvm::Type::getInt8Ty(VMContext); 1821 llvm::Type *argTypes[] = { CGF.Int64Ty, CGF.Int64Ty, Int8Ty, Int8Ty }; 1822 llvm::FunctionType *handlerTy = 1823 llvm::FunctionType::get(CGF.Int64Ty, argTypes, true); 1824 llvm::Value *handler = CGF.CGM.CreateRuntimeFunction(handlerTy, *handlerName); 1825 1826 // Sign extend the args to 64-bit, so that we can use the same handler for 1827 // all types of overflow. 1828 llvm::Value *lhs = Builder.CreateSExt(Ops.LHS, CGF.Int64Ty); 1829 llvm::Value *rhs = Builder.CreateSExt(Ops.RHS, CGF.Int64Ty); 1830 1831 // Call the handler with the two arguments, the operation, and the size of 1832 // the result. 1833 llvm::Value *handlerResult = Builder.CreateCall4(handler, lhs, rhs, 1834 Builder.getInt8(OpID), 1835 Builder.getInt8(cast<llvm::IntegerType>(opTy)->getBitWidth())); 1836 1837 // Truncate the result back to the desired size. 1838 handlerResult = Builder.CreateTrunc(handlerResult, opTy); 1839 Builder.CreateBr(continueBB); 1840 1841 Builder.SetInsertPoint(continueBB); 1842 llvm::PHINode *phi = Builder.CreatePHI(opTy, 2); 1843 phi->addIncoming(result, initialBB); 1844 phi->addIncoming(handlerResult, overflowBB); 1845 1846 return phi; 1847} 1848 1849/// Emit pointer + index arithmetic. 1850static Value *emitPointerArithmetic(CodeGenFunction &CGF, 1851 const BinOpInfo &op, 1852 bool isSubtraction) { 1853 // Must have binary (not unary) expr here. Unary pointer 1854 // increment/decrement doesn't use this path. 1855 const BinaryOperator *expr = cast<BinaryOperator>(op.E); 1856 1857 Value *pointer = op.LHS; 1858 Expr *pointerOperand = expr->getLHS(); 1859 Value *index = op.RHS; 1860 Expr *indexOperand = expr->getRHS(); 1861 1862 // In a subtraction, the LHS is always the pointer. 1863 if (!isSubtraction && !pointer->getType()->isPointerTy()) { 1864 std::swap(pointer, index); 1865 std::swap(pointerOperand, indexOperand); 1866 } 1867 1868 unsigned width = cast<llvm::IntegerType>(index->getType())->getBitWidth(); 1869 if (width != CGF.PointerWidthInBits) { 1870 // Zero-extend or sign-extend the pointer value according to 1871 // whether the index is signed or not. 1872 bool isSigned = indexOperand->getType()->isSignedIntegerOrEnumerationType(); 1873 index = CGF.Builder.CreateIntCast(index, CGF.PtrDiffTy, isSigned, 1874 "idx.ext"); 1875 } 1876 1877 // If this is subtraction, negate the index. 1878 if (isSubtraction) 1879 index = CGF.Builder.CreateNeg(index, "idx.neg"); 1880 1881 const PointerType *pointerType 1882 = pointerOperand->getType()->getAs<PointerType>(); 1883 if (!pointerType) { 1884 QualType objectType = pointerOperand->getType() 1885 ->castAs<ObjCObjectPointerType>() 1886 ->getPointeeType(); 1887 llvm::Value *objectSize 1888 = CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(objectType)); 1889 1890 index = CGF.Builder.CreateMul(index, objectSize); 1891 1892 Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy); 1893 result = CGF.Builder.CreateGEP(result, index, "add.ptr"); 1894 return CGF.Builder.CreateBitCast(result, pointer->getType()); 1895 } 1896 1897 QualType elementType = pointerType->getPointeeType(); 1898 if (const VariableArrayType *vla 1899 = CGF.getContext().getAsVariableArrayType(elementType)) { 1900 // The element count here is the total number of non-VLA elements. 1901 llvm::Value *numElements = CGF.getVLASize(vla).first; 1902 1903 // Effectively, the multiply by the VLA size is part of the GEP. 1904 // GEP indexes are signed, and scaling an index isn't permitted to 1905 // signed-overflow, so we use the same semantics for our explicit 1906 // multiply. We suppress this if overflow is not undefined behavior. 1907 if (CGF.getLangOptions().isSignedOverflowDefined()) { 1908 index = CGF.Builder.CreateMul(index, numElements, "vla.index"); 1909 pointer = CGF.Builder.CreateGEP(pointer, index, "add.ptr"); 1910 } else { 1911 index = CGF.Builder.CreateNSWMul(index, numElements, "vla.index"); 1912 pointer = CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr"); 1913 } 1914 return pointer; 1915 } 1916 1917 // Explicitly handle GNU void* and function pointer arithmetic extensions. The 1918 // GNU void* casts amount to no-ops since our void* type is i8*, but this is 1919 // future proof. 1920 if (elementType->isVoidType() || elementType->isFunctionType()) { 1921 Value *result = CGF.Builder.CreateBitCast(pointer, CGF.VoidPtrTy); 1922 result = CGF.Builder.CreateGEP(result, index, "add.ptr"); 1923 return CGF.Builder.CreateBitCast(result, pointer->getType()); 1924 } 1925 1926 if (CGF.getLangOptions().isSignedOverflowDefined()) 1927 return CGF.Builder.CreateGEP(pointer, index, "add.ptr"); 1928 1929 return CGF.Builder.CreateInBoundsGEP(pointer, index, "add.ptr"); 1930} 1931 1932Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &op) { 1933 if (op.LHS->getType()->isPointerTy() || 1934 op.RHS->getType()->isPointerTy()) 1935 return emitPointerArithmetic(CGF, op, /*subtraction*/ false); 1936 1937 if (op.Ty->isSignedIntegerOrEnumerationType()) { 1938 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1939 case LangOptions::SOB_Undefined: 1940 return Builder.CreateNSWAdd(op.LHS, op.RHS, "add"); 1941 case LangOptions::SOB_Defined: 1942 return Builder.CreateAdd(op.LHS, op.RHS, "add"); 1943 case LangOptions::SOB_Trapping: 1944 return EmitOverflowCheckedBinOp(op); 1945 } 1946 } 1947 1948 if (op.LHS->getType()->isFPOrFPVectorTy()) 1949 return Builder.CreateFAdd(op.LHS, op.RHS, "add"); 1950 1951 return Builder.CreateAdd(op.LHS, op.RHS, "add"); 1952} 1953 1954Value *ScalarExprEmitter::EmitSub(const BinOpInfo &op) { 1955 // The LHS is always a pointer if either side is. 1956 if (!op.LHS->getType()->isPointerTy()) { 1957 if (op.Ty->isSignedIntegerOrEnumerationType()) { 1958 switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) { 1959 case LangOptions::SOB_Undefined: 1960 return Builder.CreateNSWSub(op.LHS, op.RHS, "sub"); 1961 case LangOptions::SOB_Defined: 1962 return Builder.CreateSub(op.LHS, op.RHS, "sub"); 1963 case LangOptions::SOB_Trapping: 1964 return EmitOverflowCheckedBinOp(op); 1965 } 1966 } 1967 1968 if (op.LHS->getType()->isFPOrFPVectorTy()) 1969 return Builder.CreateFSub(op.LHS, op.RHS, "sub"); 1970 1971 return Builder.CreateSub(op.LHS, op.RHS, "sub"); 1972 } 1973 1974 // If the RHS is not a pointer, then we have normal pointer 1975 // arithmetic. 1976 if (!op.RHS->getType()->isPointerTy()) 1977 return emitPointerArithmetic(CGF, op, /*subtraction*/ true); 1978 1979 // Otherwise, this is a pointer subtraction. 1980 1981 // Do the raw subtraction part. 1982 llvm::Value *LHS 1983 = Builder.CreatePtrToInt(op.LHS, CGF.PtrDiffTy, "sub.ptr.lhs.cast"); 1984 llvm::Value *RHS 1985 = Builder.CreatePtrToInt(op.RHS, CGF.PtrDiffTy, "sub.ptr.rhs.cast"); 1986 Value *diffInChars = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 1987 1988 // Okay, figure out the element size. 1989 const BinaryOperator *expr = cast<BinaryOperator>(op.E); 1990 QualType elementType = expr->getLHS()->getType()->getPointeeType(); 1991 1992 llvm::Value *divisor = 0; 1993 1994 // For a variable-length array, this is going to be non-constant. 1995 if (const VariableArrayType *vla 1996 = CGF.getContext().getAsVariableArrayType(elementType)) { 1997 llvm::Value *numElements; 1998 llvm::tie(numElements, elementType) = CGF.getVLASize(vla); 1999 2000 divisor = numElements; 2001 2002 // Scale the number of non-VLA elements by the non-VLA element size. 2003 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(elementType); 2004 if (!eltSize.isOne()) 2005 divisor = CGF.Builder.CreateNUWMul(CGF.CGM.getSize(eltSize), divisor); 2006 2007 // For everything elese, we can just compute it, safe in the 2008 // assumption that Sema won't let anything through that we can't 2009 // safely compute the size of. 2010 } else { 2011 CharUnits elementSize; 2012 // Handle GCC extension for pointer arithmetic on void* and 2013 // function pointer types. 2014 if (elementType->isVoidType() || elementType->isFunctionType()) 2015 elementSize = CharUnits::One(); 2016 else 2017 elementSize = CGF.getContext().getTypeSizeInChars(elementType); 2018 2019 // Don't even emit the divide for element size of 1. 2020 if (elementSize.isOne()) 2021 return diffInChars; 2022 2023 divisor = CGF.CGM.getSize(elementSize); 2024 } 2025 2026 // Otherwise, do a full sdiv. This uses the "exact" form of sdiv, since 2027 // pointer difference in C is only defined in the case where both operands 2028 // are pointing to elements of an array. 2029 return Builder.CreateExactSDiv(diffInChars, divisor, "sub.ptr.div"); 2030} 2031 2032Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 2033 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 2034 // RHS to the same size as the LHS. 2035 Value *RHS = Ops.RHS; 2036 if (Ops.LHS->getType() != RHS->getType()) 2037 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 2038 2039 if (CGF.CatchUndefined 2040 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 2041 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 2042 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 2043 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 2044 llvm::ConstantInt::get(RHS->getType(), Width)), 2045 Cont, CGF.getTrapBB()); 2046 CGF.EmitBlock(Cont); 2047 } 2048 2049 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 2050} 2051 2052Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 2053 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 2054 // RHS to the same size as the LHS. 2055 Value *RHS = Ops.RHS; 2056 if (Ops.LHS->getType() != RHS->getType()) 2057 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 2058 2059 if (CGF.CatchUndefined 2060 && isa<llvm::IntegerType>(Ops.LHS->getType())) { 2061 unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth(); 2062 llvm::BasicBlock *Cont = CGF.createBasicBlock("cont"); 2063 CGF.Builder.CreateCondBr(Builder.CreateICmpULT(RHS, 2064 llvm::ConstantInt::get(RHS->getType(), Width)), 2065 Cont, CGF.getTrapBB()); 2066 CGF.EmitBlock(Cont); 2067 } 2068 2069 if (Ops.Ty->hasUnsignedIntegerRepresentation()) 2070 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 2071 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 2072} 2073 2074enum IntrinsicType { VCMPEQ, VCMPGT }; 2075// return corresponding comparison intrinsic for given vector type 2076static llvm::Intrinsic::ID GetIntrinsic(IntrinsicType IT, 2077 BuiltinType::Kind ElemKind) { 2078 switch (ElemKind) { 2079 default: llvm_unreachable("unexpected element type"); 2080 case BuiltinType::Char_U: 2081 case BuiltinType::UChar: 2082 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p : 2083 llvm::Intrinsic::ppc_altivec_vcmpgtub_p; 2084 break; 2085 case BuiltinType::Char_S: 2086 case BuiltinType::SChar: 2087 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p : 2088 llvm::Intrinsic::ppc_altivec_vcmpgtsb_p; 2089 break; 2090 case BuiltinType::UShort: 2091 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p : 2092 llvm::Intrinsic::ppc_altivec_vcmpgtuh_p; 2093 break; 2094 case BuiltinType::Short: 2095 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p : 2096 llvm::Intrinsic::ppc_altivec_vcmpgtsh_p; 2097 break; 2098 case BuiltinType::UInt: 2099 case BuiltinType::ULong: 2100 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p : 2101 llvm::Intrinsic::ppc_altivec_vcmpgtuw_p; 2102 break; 2103 case BuiltinType::Int: 2104 case BuiltinType::Long: 2105 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p : 2106 llvm::Intrinsic::ppc_altivec_vcmpgtsw_p; 2107 break; 2108 case BuiltinType::Float: 2109 return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpeqfp_p : 2110 llvm::Intrinsic::ppc_altivec_vcmpgtfp_p; 2111 break; 2112 } 2113 return llvm::Intrinsic::not_intrinsic; 2114} 2115 2116Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 2117 unsigned SICmpOpc, unsigned FCmpOpc) { 2118 TestAndClearIgnoreResultAssign(); 2119 Value *Result; 2120 QualType LHSTy = E->getLHS()->getType(); 2121 if (const MemberPointerType *MPT = LHSTy->getAs<MemberPointerType>()) { 2122 assert(E->getOpcode() == BO_EQ || 2123 E->getOpcode() == BO_NE); 2124 Value *LHS = CGF.EmitScalarExpr(E->getLHS()); 2125 Value *RHS = CGF.EmitScalarExpr(E->getRHS()); 2126 Result = CGF.CGM.getCXXABI().EmitMemberPointerComparison( 2127 CGF, LHS, RHS, MPT, E->getOpcode() == BO_NE); 2128 } else if (!LHSTy->isAnyComplexType()) { 2129 Value *LHS = Visit(E->getLHS()); 2130 Value *RHS = Visit(E->getRHS()); 2131 2132 // If AltiVec, the comparison results in a numeric type, so we use 2133 // intrinsics comparing vectors and giving 0 or 1 as a result 2134 if (LHSTy->isVectorType() && !E->getType()->isVectorType()) { 2135 // constants for mapping CR6 register bits to predicate result 2136 enum { CR6_EQ=0, CR6_EQ_REV, CR6_LT, CR6_LT_REV } CR6; 2137 2138 llvm::Intrinsic::ID ID = llvm::Intrinsic::not_intrinsic; 2139 2140 // in several cases vector arguments order will be reversed 2141 Value *FirstVecArg = LHS, 2142 *SecondVecArg = RHS; 2143 2144 QualType ElTy = LHSTy->getAs<VectorType>()->getElementType(); 2145 const BuiltinType *BTy = ElTy->getAs<BuiltinType>(); 2146 BuiltinType::Kind ElementKind = BTy->getKind(); 2147 2148 switch(E->getOpcode()) { 2149 default: llvm_unreachable("is not a comparison operation"); 2150 case BO_EQ: 2151 CR6 = CR6_LT; 2152 ID = GetIntrinsic(VCMPEQ, ElementKind); 2153 break; 2154 case BO_NE: 2155 CR6 = CR6_EQ; 2156 ID = GetIntrinsic(VCMPEQ, ElementKind); 2157 break; 2158 case BO_LT: 2159 CR6 = CR6_LT; 2160 ID = GetIntrinsic(VCMPGT, ElementKind); 2161 std::swap(FirstVecArg, SecondVecArg); 2162 break; 2163 case BO_GT: 2164 CR6 = CR6_LT; 2165 ID = GetIntrinsic(VCMPGT, ElementKind); 2166 break; 2167 case BO_LE: 2168 if (ElementKind == BuiltinType::Float) { 2169 CR6 = CR6_LT; 2170 ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p; 2171 std::swap(FirstVecArg, SecondVecArg); 2172 } 2173 else { 2174 CR6 = CR6_EQ; 2175 ID = GetIntrinsic(VCMPGT, ElementKind); 2176 } 2177 break; 2178 case BO_GE: 2179 if (ElementKind == BuiltinType::Float) { 2180 CR6 = CR6_LT; 2181 ID = llvm::Intrinsic::ppc_altivec_vcmpgefp_p; 2182 } 2183 else { 2184 CR6 = CR6_EQ; 2185 ID = GetIntrinsic(VCMPGT, ElementKind); 2186 std::swap(FirstVecArg, SecondVecArg); 2187 } 2188 break; 2189 } 2190 2191 Value *CR6Param = Builder.getInt32(CR6); 2192 llvm::Function *F = CGF.CGM.getIntrinsic(ID); 2193 Result = Builder.CreateCall3(F, CR6Param, FirstVecArg, SecondVecArg, ""); 2194 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 2195 } 2196 2197 if (LHS->getType()->isFPOrFPVectorTy()) { 2198 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 2199 LHS, RHS, "cmp"); 2200 } else if (LHSTy->hasSignedIntegerRepresentation()) { 2201 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 2202 LHS, RHS, "cmp"); 2203 } else { 2204 // Unsigned integers and pointers. 2205 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2206 LHS, RHS, "cmp"); 2207 } 2208 2209 // If this is a vector comparison, sign extend the result to the appropriate 2210 // vector integer type and return it (don't convert to bool). 2211 if (LHSTy->isVectorType()) 2212 return Builder.CreateSExt(Result, ConvertType(E->getType()), "sext"); 2213 2214 } else { 2215 // Complex Comparison: can only be an equality comparison. 2216 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 2217 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 2218 2219 QualType CETy = LHSTy->getAs<ComplexType>()->getElementType(); 2220 2221 Value *ResultR, *ResultI; 2222 if (CETy->isRealFloatingType()) { 2223 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 2224 LHS.first, RHS.first, "cmp.r"); 2225 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 2226 LHS.second, RHS.second, "cmp.i"); 2227 } else { 2228 // Complex comparisons can only be equality comparisons. As such, signed 2229 // and unsigned opcodes are the same. 2230 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2231 LHS.first, RHS.first, "cmp.r"); 2232 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 2233 LHS.second, RHS.second, "cmp.i"); 2234 } 2235 2236 if (E->getOpcode() == BO_EQ) { 2237 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 2238 } else { 2239 assert(E->getOpcode() == BO_NE && 2240 "Complex comparison other than == or != ?"); 2241 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 2242 } 2243 } 2244 2245 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 2246} 2247 2248Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 2249 bool Ignore = TestAndClearIgnoreResultAssign(); 2250 2251 Value *RHS; 2252 LValue LHS; 2253 2254 switch (E->getLHS()->getType().getObjCLifetime()) { 2255 case Qualifiers::OCL_Strong: 2256 llvm::tie(LHS, RHS) = CGF.EmitARCStoreStrong(E, Ignore); 2257 break; 2258 2259 case Qualifiers::OCL_Autoreleasing: 2260 llvm::tie(LHS,RHS) = CGF.EmitARCStoreAutoreleasing(E); 2261 break; 2262 2263 case Qualifiers::OCL_Weak: 2264 RHS = Visit(E->getRHS()); 2265 LHS = EmitCheckedLValue(E->getLHS()); 2266 RHS = CGF.EmitARCStoreWeak(LHS.getAddress(), RHS, Ignore); 2267 break; 2268 2269 // No reason to do any of these differently. 2270 case Qualifiers::OCL_None: 2271 case Qualifiers::OCL_ExplicitNone: 2272 // __block variables need to have the rhs evaluated first, plus 2273 // this should improve codegen just a little. 2274 RHS = Visit(E->getRHS()); 2275 LHS = EmitCheckedLValue(E->getLHS()); 2276 2277 // Store the value into the LHS. Bit-fields are handled specially 2278 // because the result is altered by the store, i.e., [C99 6.5.16p1] 2279 // 'An assignment expression has the value of the left operand after 2280 // the assignment...'. 2281 if (LHS.isBitField()) 2282 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, &RHS); 2283 else 2284 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS); 2285 } 2286 2287 // If the result is clearly ignored, return now. 2288 if (Ignore) 2289 return 0; 2290 2291 // The result of an assignment in C is the assigned r-value. 2292 if (!CGF.getContext().getLangOptions().CPlusPlus) 2293 return RHS; 2294 2295 // Objective-C property assignment never reloads the value following a store. 2296 if (LHS.isPropertyRef()) 2297 return RHS; 2298 2299 // If the lvalue is non-volatile, return the computed value of the assignment. 2300 if (!LHS.isVolatileQualified()) 2301 return RHS; 2302 2303 // Otherwise, reload the value. 2304 return EmitLoadOfLValue(LHS); 2305} 2306 2307Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 2308 llvm::Type *ResTy = ConvertType(E->getType()); 2309 2310 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 2311 // If we have 1 && X, just emit X without inserting the control flow. 2312 bool LHSCondVal; 2313 if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) { 2314 if (LHSCondVal) { // If we have 1 && X, just emit X. 2315 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2316 // ZExt result to int or bool. 2317 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext"); 2318 } 2319 2320 // 0 && RHS: If it is safe, just elide the RHS, and return 0/false. 2321 if (!CGF.ContainsLabel(E->getRHS())) 2322 return llvm::Constant::getNullValue(ResTy); 2323 } 2324 2325 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 2326 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 2327 2328 CodeGenFunction::ConditionalEvaluation eval(CGF); 2329 2330 // Branch on the LHS first. If it is false, go to the failure (cont) block. 2331 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 2332 2333 // Any edges into the ContBlock are now from an (indeterminate number of) 2334 // edges from this first condition. All of these values will be false. Start 2335 // setting up the PHI node in the Cont Block for this. 2336 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2, 2337 "", ContBlock); 2338 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 2339 PI != PE; ++PI) 2340 PN->addIncoming(llvm::ConstantInt::getFalse(VMContext), *PI); 2341 2342 eval.begin(CGF); 2343 CGF.EmitBlock(RHSBlock); 2344 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2345 eval.end(CGF); 2346 2347 // Reaquire the RHS block, as there may be subblocks inserted. 2348 RHSBlock = Builder.GetInsertBlock(); 2349 2350 // Emit an unconditional branch from this block to ContBlock. Insert an entry 2351 // into the phi node for the edge with the value of RHSCond. 2352 if (CGF.getDebugInfo()) 2353 // There is no need to emit line number for unconditional branch. 2354 Builder.SetCurrentDebugLocation(llvm::DebugLoc()); 2355 CGF.EmitBlock(ContBlock); 2356 PN->addIncoming(RHSCond, RHSBlock); 2357 2358 // ZExt result to int. 2359 return Builder.CreateZExtOrBitCast(PN, ResTy, "land.ext"); 2360} 2361 2362Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 2363 llvm::Type *ResTy = ConvertType(E->getType()); 2364 2365 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 2366 // If we have 0 || X, just emit X without inserting the control flow. 2367 bool LHSCondVal; 2368 if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) { 2369 if (!LHSCondVal) { // If we have 0 || X, just emit X. 2370 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2371 // ZExt result to int or bool. 2372 return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext"); 2373 } 2374 2375 // 1 || RHS: If it is safe, just elide the RHS, and return 1/true. 2376 if (!CGF.ContainsLabel(E->getRHS())) 2377 return llvm::ConstantInt::get(ResTy, 1); 2378 } 2379 2380 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 2381 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 2382 2383 CodeGenFunction::ConditionalEvaluation eval(CGF); 2384 2385 // Branch on the LHS first. If it is true, go to the success (cont) block. 2386 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 2387 2388 // Any edges into the ContBlock are now from an (indeterminate number of) 2389 // edges from this first condition. All of these values will be true. Start 2390 // setting up the PHI node in the Cont Block for this. 2391 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::getInt1Ty(VMContext), 2, 2392 "", ContBlock); 2393 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 2394 PI != PE; ++PI) 2395 PN->addIncoming(llvm::ConstantInt::getTrue(VMContext), *PI); 2396 2397 eval.begin(CGF); 2398 2399 // Emit the RHS condition as a bool value. 2400 CGF.EmitBlock(RHSBlock); 2401 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 2402 2403 eval.end(CGF); 2404 2405 // Reaquire the RHS block, as there may be subblocks inserted. 2406 RHSBlock = Builder.GetInsertBlock(); 2407 2408 // Emit an unconditional branch from this block to ContBlock. Insert an entry 2409 // into the phi node for the edge with the value of RHSCond. 2410 CGF.EmitBlock(ContBlock); 2411 PN->addIncoming(RHSCond, RHSBlock); 2412 2413 // ZExt result to int. 2414 return Builder.CreateZExtOrBitCast(PN, ResTy, "lor.ext"); 2415} 2416 2417Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 2418 CGF.EmitIgnoredExpr(E->getLHS()); 2419 CGF.EnsureInsertPoint(); 2420 return Visit(E->getRHS()); 2421} 2422 2423//===----------------------------------------------------------------------===// 2424// Other Operators 2425//===----------------------------------------------------------------------===// 2426 2427/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 2428/// expression is cheap enough and side-effect-free enough to evaluate 2429/// unconditionally instead of conditionally. This is used to convert control 2430/// flow into selects in some cases. 2431static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E, 2432 CodeGenFunction &CGF) { 2433 E = E->IgnoreParens(); 2434 2435 // Anything that is an integer or floating point constant is fine. 2436 if (E->isConstantInitializer(CGF.getContext(), false)) 2437 return true; 2438 2439 // Non-volatile automatic variables too, to get "cond ? X : Y" where 2440 // X and Y are local variables. 2441 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 2442 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 2443 if (VD->hasLocalStorage() && !(CGF.getContext() 2444 .getCanonicalType(VD->getType()) 2445 .isVolatileQualified())) 2446 return true; 2447 2448 return false; 2449} 2450 2451 2452Value *ScalarExprEmitter:: 2453VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) { 2454 TestAndClearIgnoreResultAssign(); 2455 2456 // Bind the common expression if necessary. 2457 CodeGenFunction::OpaqueValueMapping binding(CGF, E); 2458 2459 Expr *condExpr = E->getCond(); 2460 Expr *lhsExpr = E->getTrueExpr(); 2461 Expr *rhsExpr = E->getFalseExpr(); 2462 2463 // If the condition constant folds and can be elided, try to avoid emitting 2464 // the condition and the dead arm. 2465 bool CondExprBool; 2466 if (CGF.ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) { 2467 Expr *live = lhsExpr, *dead = rhsExpr; 2468 if (!CondExprBool) std::swap(live, dead); 2469 2470 // If the dead side doesn't have labels we need, and if the Live side isn't 2471 // the gnu missing ?: extension (which we could handle, but don't bother 2472 // to), just emit the Live part. 2473 if (!CGF.ContainsLabel(dead)) 2474 return Visit(live); 2475 } 2476 2477 // OpenCL: If the condition is a vector, we can treat this condition like 2478 // the select function. 2479 if (CGF.getContext().getLangOptions().OpenCL 2480 && condExpr->getType()->isVectorType()) { 2481 llvm::Value *CondV = CGF.EmitScalarExpr(condExpr); 2482 llvm::Value *LHS = Visit(lhsExpr); 2483 llvm::Value *RHS = Visit(rhsExpr); 2484 2485 llvm::Type *condType = ConvertType(condExpr->getType()); 2486 llvm::VectorType *vecTy = cast<llvm::VectorType>(condType); 2487 2488 unsigned numElem = vecTy->getNumElements(); 2489 llvm::Type *elemType = vecTy->getElementType(); 2490 2491 std::vector<llvm::Constant*> Zvals; 2492 for (unsigned i = 0; i < numElem; ++i) 2493 Zvals.push_back(llvm::ConstantInt::get(elemType, 0)); 2494 2495 llvm::Value *zeroVec = llvm::ConstantVector::get(Zvals); 2496 llvm::Value *TestMSB = Builder.CreateICmpSLT(CondV, zeroVec); 2497 llvm::Value *tmp = Builder.CreateSExt(TestMSB, 2498 llvm::VectorType::get(elemType, 2499 numElem), 2500 "sext"); 2501 llvm::Value *tmp2 = Builder.CreateNot(tmp); 2502 2503 // Cast float to int to perform ANDs if necessary. 2504 llvm::Value *RHSTmp = RHS; 2505 llvm::Value *LHSTmp = LHS; 2506 bool wasCast = false; 2507 llvm::VectorType *rhsVTy = cast<llvm::VectorType>(RHS->getType()); 2508 if (rhsVTy->getElementType()->isFloatTy()) { 2509 RHSTmp = Builder.CreateBitCast(RHS, tmp2->getType()); 2510 LHSTmp = Builder.CreateBitCast(LHS, tmp->getType()); 2511 wasCast = true; 2512 } 2513 2514 llvm::Value *tmp3 = Builder.CreateAnd(RHSTmp, tmp2); 2515 llvm::Value *tmp4 = Builder.CreateAnd(LHSTmp, tmp); 2516 llvm::Value *tmp5 = Builder.CreateOr(tmp3, tmp4, "cond"); 2517 if (wasCast) 2518 tmp5 = Builder.CreateBitCast(tmp5, RHS->getType()); 2519 2520 return tmp5; 2521 } 2522 2523 // If this is a really simple expression (like x ? 4 : 5), emit this as a 2524 // select instead of as control flow. We can only do this if it is cheap and 2525 // safe to evaluate the LHS and RHS unconditionally. 2526 if (isCheapEnoughToEvaluateUnconditionally(lhsExpr, CGF) && 2527 isCheapEnoughToEvaluateUnconditionally(rhsExpr, CGF)) { 2528 llvm::Value *CondV = CGF.EvaluateExprAsBool(condExpr); 2529 llvm::Value *LHS = Visit(lhsExpr); 2530 llvm::Value *RHS = Visit(rhsExpr); 2531 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 2532 } 2533 2534 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 2535 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 2536 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 2537 2538 CodeGenFunction::ConditionalEvaluation eval(CGF); 2539 CGF.EmitBranchOnBoolExpr(condExpr, LHSBlock, RHSBlock); 2540 2541 CGF.EmitBlock(LHSBlock); 2542 eval.begin(CGF); 2543 Value *LHS = Visit(lhsExpr); 2544 eval.end(CGF); 2545 2546 LHSBlock = Builder.GetInsertBlock(); 2547 Builder.CreateBr(ContBlock); 2548 2549 CGF.EmitBlock(RHSBlock); 2550 eval.begin(CGF); 2551 Value *RHS = Visit(rhsExpr); 2552 eval.end(CGF); 2553 2554 RHSBlock = Builder.GetInsertBlock(); 2555 CGF.EmitBlock(ContBlock); 2556 2557 // If the LHS or RHS is a throw expression, it will be legitimately null. 2558 if (!LHS) 2559 return RHS; 2560 if (!RHS) 2561 return LHS; 2562 2563 // Create a PHI node for the real part. 2564 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), 2, "cond"); 2565 PN->addIncoming(LHS, LHSBlock); 2566 PN->addIncoming(RHS, RHSBlock); 2567 return PN; 2568} 2569 2570Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 2571 return Visit(E->getChosenSubExpr(CGF.getContext())); 2572} 2573 2574Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 2575 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 2576 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 2577 2578 // If EmitVAArg fails, we fall back to the LLVM instruction. 2579 if (!ArgPtr) 2580 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 2581 2582 // FIXME Volatility. 2583 return Builder.CreateLoad(ArgPtr); 2584} 2585 2586Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *block) { 2587 return CGF.EmitBlockLiteral(block); 2588} 2589 2590Value *ScalarExprEmitter::VisitAsTypeExpr(AsTypeExpr *E) { 2591 Value *Src = CGF.EmitScalarExpr(E->getSrcExpr()); 2592 llvm::Type *DstTy = ConvertType(E->getType()); 2593 2594 // Going from vec4->vec3 or vec3->vec4 is a special case and requires 2595 // a shuffle vector instead of a bitcast. 2596 llvm::Type *SrcTy = Src->getType(); 2597 if (isa<llvm::VectorType>(DstTy) && isa<llvm::VectorType>(SrcTy)) { 2598 unsigned numElementsDst = cast<llvm::VectorType>(DstTy)->getNumElements(); 2599 unsigned numElementsSrc = cast<llvm::VectorType>(SrcTy)->getNumElements(); 2600 if ((numElementsDst == 3 && numElementsSrc == 4) 2601 || (numElementsDst == 4 && numElementsSrc == 3)) { 2602 2603 2604 // In the case of going from int4->float3, a bitcast is needed before 2605 // doing a shuffle. 2606 llvm::Type *srcElemTy = 2607 cast<llvm::VectorType>(SrcTy)->getElementType(); 2608 llvm::Type *dstElemTy = 2609 cast<llvm::VectorType>(DstTy)->getElementType(); 2610 2611 if ((srcElemTy->isIntegerTy() && dstElemTy->isFloatTy()) 2612 || (srcElemTy->isFloatTy() && dstElemTy->isIntegerTy())) { 2613 // Create a float type of the same size as the source or destination. 2614 llvm::VectorType *newSrcTy = llvm::VectorType::get(dstElemTy, 2615 numElementsSrc); 2616 2617 Src = Builder.CreateBitCast(Src, newSrcTy, "astypeCast"); 2618 } 2619 2620 llvm::Value *UnV = llvm::UndefValue::get(Src->getType()); 2621 2622 SmallVector<llvm::Constant*, 3> Args; 2623 Args.push_back(Builder.getInt32(0)); 2624 Args.push_back(Builder.getInt32(1)); 2625 Args.push_back(Builder.getInt32(2)); 2626 2627 if (numElementsDst == 4) 2628 Args.push_back(llvm::UndefValue::get( 2629 llvm::Type::getInt32Ty(CGF.getLLVMContext()))); 2630 2631 llvm::Constant *Mask = llvm::ConstantVector::get(Args); 2632 2633 return Builder.CreateShuffleVector(Src, UnV, Mask, "astype"); 2634 } 2635 } 2636 2637 return Builder.CreateBitCast(Src, DstTy, "astype"); 2638} 2639 2640//===----------------------------------------------------------------------===// 2641// Entry Point into this File 2642//===----------------------------------------------------------------------===// 2643 2644/// EmitScalarExpr - Emit the computation of the specified expression of scalar 2645/// type, ignoring the result. 2646Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { 2647 assert(E && !hasAggregateLLVMType(E->getType()) && 2648 "Invalid scalar expression to emit"); 2649 2650 if (isa<CXXDefaultArgExpr>(E)) 2651 disableDebugInfo(); 2652 Value *V = ScalarExprEmitter(*this, IgnoreResultAssign) 2653 .Visit(const_cast<Expr*>(E)); 2654 if (isa<CXXDefaultArgExpr>(E)) 2655 enableDebugInfo(); 2656 return V; 2657} 2658 2659/// EmitScalarConversion - Emit a conversion from the specified type to the 2660/// specified destination type, both of which are LLVM scalar types. 2661Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 2662 QualType DstTy) { 2663 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 2664 "Invalid scalar expression to emit"); 2665 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 2666} 2667 2668/// EmitComplexToScalarConversion - Emit a conversion from the specified complex 2669/// type to the specified destination type, where the destination type is an 2670/// LLVM scalar type. 2671Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 2672 QualType SrcTy, 2673 QualType DstTy) { 2674 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 2675 "Invalid complex -> scalar conversion"); 2676 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 2677 DstTy); 2678} 2679 2680 2681llvm::Value *CodeGenFunction:: 2682EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV, 2683 bool isInc, bool isPre) { 2684 return ScalarExprEmitter(*this).EmitScalarPrePostIncDec(E, LV, isInc, isPre); 2685} 2686 2687LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) { 2688 llvm::Value *V; 2689 // object->isa or (*object).isa 2690 // Generate code as for: *(Class*)object 2691 // build Class* type 2692 llvm::Type *ClassPtrTy = ConvertType(E->getType()); 2693 2694 Expr *BaseExpr = E->getBase(); 2695 if (BaseExpr->isRValue()) { 2696 V = CreateTempAlloca(ClassPtrTy, "resval"); 2697 llvm::Value *Src = EmitScalarExpr(BaseExpr); 2698 Builder.CreateStore(Src, V); 2699 V = ScalarExprEmitter(*this).EmitLoadOfLValue( 2700 MakeAddrLValue(V, E->getType())); 2701 } else { 2702 if (E->isArrow()) 2703 V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr); 2704 else 2705 V = EmitLValue(BaseExpr).getAddress(); 2706 } 2707 2708 // build Class* type 2709 ClassPtrTy = ClassPtrTy->getPointerTo(); 2710 V = Builder.CreateBitCast(V, ClassPtrTy); 2711 return MakeAddrLValue(V, E->getType()); 2712} 2713 2714 2715LValue CodeGenFunction::EmitCompoundAssignmentLValue( 2716 const CompoundAssignOperator *E) { 2717 ScalarExprEmitter Scalar(*this); 2718 Value *Result = 0; 2719 switch (E->getOpcode()) { 2720#define COMPOUND_OP(Op) \ 2721 case BO_##Op##Assign: \ 2722 return Scalar.EmitCompoundAssignLValue(E, &ScalarExprEmitter::Emit##Op, \ 2723 Result) 2724 COMPOUND_OP(Mul); 2725 COMPOUND_OP(Div); 2726 COMPOUND_OP(Rem); 2727 COMPOUND_OP(Add); 2728 COMPOUND_OP(Sub); 2729 COMPOUND_OP(Shl); 2730 COMPOUND_OP(Shr); 2731 COMPOUND_OP(And); 2732 COMPOUND_OP(Xor); 2733 COMPOUND_OP(Or); 2734#undef COMPOUND_OP 2735 2736 case BO_PtrMemD: 2737 case BO_PtrMemI: 2738 case BO_Mul: 2739 case BO_Div: 2740 case BO_Rem: 2741 case BO_Add: 2742 case BO_Sub: 2743 case BO_Shl: 2744 case BO_Shr: 2745 case BO_LT: 2746 case BO_GT: 2747 case BO_LE: 2748 case BO_GE: 2749 case BO_EQ: 2750 case BO_NE: 2751 case BO_And: 2752 case BO_Xor: 2753 case BO_Or: 2754 case BO_LAnd: 2755 case BO_LOr: 2756 case BO_Assign: 2757 case BO_Comma: 2758 llvm_unreachable("Not valid compound assignment operators"); 2759 } 2760 2761 llvm_unreachable("Unhandled compound assignment operator"); 2762} 2763