CGExprScalar.cpp revision 12d152f61ccef9a2c0372ba39be7cf416c6e1a9e
1//===--- CGExprScalar.cpp - Emit LLVM Code for Scalar Exprs ---------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This contains code to emit Expr nodes with scalar LLVM types as LLVM code. 11// 12//===----------------------------------------------------------------------===// 13 14#include "CodeGenFunction.h" 15#include "CodeGenModule.h" 16#include "clang/AST/ASTContext.h" 17#include "clang/AST/DeclObjC.h" 18#include "clang/AST/RecordLayout.h" 19#include "clang/AST/StmtVisitor.h" 20#include "clang/Basic/TargetInfo.h" 21#include "llvm/Constants.h" 22#include "llvm/Function.h" 23#include "llvm/GlobalVariable.h" 24#include "llvm/Intrinsics.h" 25#include "llvm/Support/Compiler.h" 26#include "llvm/Support/CFG.h" 27#include <cstdarg> 28 29using namespace clang; 30using namespace CodeGen; 31using llvm::Value; 32 33//===----------------------------------------------------------------------===// 34// Scalar Expression Emitter 35//===----------------------------------------------------------------------===// 36 37struct BinOpInfo { 38 Value *LHS; 39 Value *RHS; 40 QualType Ty; // Computation Type. 41 const BinaryOperator *E; 42}; 43 44namespace { 45class VISIBILITY_HIDDEN ScalarExprEmitter 46 : public StmtVisitor<ScalarExprEmitter, Value*> { 47 CodeGenFunction &CGF; 48 CGBuilderTy &Builder; 49 50public: 51 52 ScalarExprEmitter(CodeGenFunction &cgf) : CGF(cgf), 53 Builder(CGF.Builder) { 54 } 55 56 //===--------------------------------------------------------------------===// 57 // Utilities 58 //===--------------------------------------------------------------------===// 59 60 const llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); } 61 LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); } 62 63 Value *EmitLoadOfLValue(LValue LV, QualType T) { 64 return CGF.EmitLoadOfLValue(LV, T).getScalarVal(); 65 } 66 67 /// EmitLoadOfLValue - Given an expression with complex type that represents a 68 /// value l-value, this method emits the address of the l-value, then loads 69 /// and returns the result. 70 Value *EmitLoadOfLValue(const Expr *E) { 71 // FIXME: Volatile 72 return EmitLoadOfLValue(EmitLValue(E), E->getType()); 73 } 74 75 /// EmitConversionToBool - Convert the specified expression value to a 76 /// boolean (i1) truth value. This is equivalent to "Val != 0". 77 Value *EmitConversionToBool(Value *Src, QualType DstTy); 78 79 /// EmitScalarConversion - Emit a conversion from the specified type to the 80 /// specified destination type, both of which are LLVM scalar types. 81 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); 82 83 /// EmitComplexToScalarConversion - Emit a conversion from the specified 84 /// complex type to the specified destination type, where the destination 85 /// type is an LLVM scalar type. 86 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 87 QualType SrcTy, QualType DstTy); 88 89 //===--------------------------------------------------------------------===// 90 // Visitor Methods 91 //===--------------------------------------------------------------------===// 92 93 Value *VisitStmt(Stmt *S) { 94 S->dump(CGF.getContext().getSourceManager()); 95 assert(0 && "Stmt can't have complex result type!"); 96 return 0; 97 } 98 Value *VisitExpr(Expr *S); 99 Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); } 100 101 // Leaves. 102 Value *VisitIntegerLiteral(const IntegerLiteral *E) { 103 return llvm::ConstantInt::get(E->getValue()); 104 } 105 Value *VisitFloatingLiteral(const FloatingLiteral *E) { 106 return llvm::ConstantFP::get(E->getValue()); 107 } 108 Value *VisitCharacterLiteral(const CharacterLiteral *E) { 109 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 110 } 111 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 112 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 113 } 114 Value *VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) { 115 return llvm::Constant::getNullValue(ConvertType(E->getType())); 116 } 117 Value *VisitGNUNullExpr(const GNUNullExpr *E) { 118 return llvm::Constant::getNullValue(ConvertType(E->getType())); 119 } 120 Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { 121 return llvm::ConstantInt::get(ConvertType(E->getType()), 122 CGF.getContext().typesAreCompatible( 123 E->getArgType1(), E->getArgType2())); 124 } 125 Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); 126 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 127 llvm::Value *V = 128 llvm::ConstantInt::get(llvm::Type::Int32Ty, 129 CGF.GetIDForAddrOfLabel(E->getLabel())); 130 131 return Builder.CreateIntToPtr(V, ConvertType(E->getType())); 132 } 133 134 // l-values. 135 Value *VisitDeclRefExpr(DeclRefExpr *E) { 136 if (const EnumConstantDecl *EC = dyn_cast<EnumConstantDecl>(E->getDecl())) 137 return llvm::ConstantInt::get(EC->getInitVal()); 138 return EmitLoadOfLValue(E); 139 } 140 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 141 return CGF.EmitObjCSelectorExpr(E); 142 } 143 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 144 return CGF.EmitObjCProtocolExpr(E); 145 } 146 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 147 return EmitLoadOfLValue(E); 148 } 149 Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { 150 return EmitLoadOfLValue(E); 151 } 152 Value *VisitObjCKVCRefExpr(ObjCKVCRefExpr *E) { 153 return EmitLoadOfLValue(E); 154 } 155 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 156 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 157 } 158 159 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 160 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 161 Value *VisitMemberExpr(Expr *E) { return EmitLoadOfLValue(E); } 162 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 163 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 164 return EmitLoadOfLValue(E); 165 } 166 Value *VisitStringLiteral(Expr *E) { return EmitLValue(E).getAddress(); } 167 Value *VisitPredefinedExpr(Expr *E) { return EmitLValue(E).getAddress(); } 168 169 Value *VisitInitListExpr(InitListExpr *E) { 170 unsigned NumInitElements = E->getNumInits(); 171 172 if (E->hadArrayRangeDesignator()) { 173 CGF.ErrorUnsupported(E, "GNU array range designator extension"); 174 } 175 176 const llvm::VectorType *VType = 177 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 178 179 // We have a scalar in braces. Just use the first element. 180 if (!VType) 181 return Visit(E->getInit(0)); 182 183 unsigned NumVectorElements = VType->getNumElements(); 184 const llvm::Type *ElementType = VType->getElementType(); 185 186 // Emit individual vector element stores. 187 llvm::Value *V = llvm::UndefValue::get(VType); 188 189 // Emit initializers 190 unsigned i; 191 for (i = 0; i < NumInitElements; ++i) { 192 Value *NewV = Visit(E->getInit(i)); 193 Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); 194 V = Builder.CreateInsertElement(V, NewV, Idx); 195 } 196 197 // Emit remaining default initializers 198 for (/* Do not initialize i*/; i < NumVectorElements; ++i) { 199 Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); 200 llvm::Value *NewV = llvm::Constant::getNullValue(ElementType); 201 V = Builder.CreateInsertElement(V, NewV, Idx); 202 } 203 204 return V; 205 } 206 207 Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { 208 return llvm::Constant::getNullValue(ConvertType(E->getType())); 209 } 210 Value *VisitImplicitCastExpr(const ImplicitCastExpr *E); 211 Value *VisitCastExpr(const CastExpr *E) { 212 return EmitCastExpr(E->getSubExpr(), E->getType()); 213 } 214 Value *EmitCastExpr(const Expr *E, QualType T); 215 216 Value *VisitCallExpr(const CallExpr *E) { 217 return CGF.EmitCallExpr(E).getScalarVal(); 218 } 219 220 Value *VisitStmtExpr(const StmtExpr *E); 221 222 // Unary Operators. 223 Value *VisitPrePostIncDec(const UnaryOperator *E, bool isInc, bool isPre); 224 Value *VisitUnaryPostDec(const UnaryOperator *E) { 225 return VisitPrePostIncDec(E, false, false); 226 } 227 Value *VisitUnaryPostInc(const UnaryOperator *E) { 228 return VisitPrePostIncDec(E, true, false); 229 } 230 Value *VisitUnaryPreDec(const UnaryOperator *E) { 231 return VisitPrePostIncDec(E, false, true); 232 } 233 Value *VisitUnaryPreInc(const UnaryOperator *E) { 234 return VisitPrePostIncDec(E, true, true); 235 } 236 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 237 return EmitLValue(E->getSubExpr()).getAddress(); 238 } 239 Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } 240 Value *VisitUnaryPlus(const UnaryOperator *E) { 241 return Visit(E->getSubExpr()); 242 } 243 Value *VisitUnaryMinus (const UnaryOperator *E); 244 Value *VisitUnaryNot (const UnaryOperator *E); 245 Value *VisitUnaryLNot (const UnaryOperator *E); 246 Value *VisitUnaryReal (const UnaryOperator *E); 247 Value *VisitUnaryImag (const UnaryOperator *E); 248 Value *VisitUnaryExtension(const UnaryOperator *E) { 249 return Visit(E->getSubExpr()); 250 } 251 Value *VisitUnaryOffsetOf(const UnaryOperator *E); 252 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 253 return Visit(DAE->getExpr()); 254 } 255 256 // Binary Operators. 257 Value *EmitMul(const BinOpInfo &Ops) { 258 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 259 } 260 Value *EmitDiv(const BinOpInfo &Ops); 261 Value *EmitRem(const BinOpInfo &Ops); 262 Value *EmitAdd(const BinOpInfo &Ops); 263 Value *EmitSub(const BinOpInfo &Ops); 264 Value *EmitShl(const BinOpInfo &Ops); 265 Value *EmitShr(const BinOpInfo &Ops); 266 Value *EmitAnd(const BinOpInfo &Ops) { 267 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 268 } 269 Value *EmitXor(const BinOpInfo &Ops) { 270 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 271 } 272 Value *EmitOr (const BinOpInfo &Ops) { 273 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 274 } 275 276 BinOpInfo EmitBinOps(const BinaryOperator *E); 277 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 278 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 279 280 // Binary operators and binary compound assignment operators. 281#define HANDLEBINOP(OP) \ 282 Value *VisitBin ## OP(const BinaryOperator *E) { \ 283 return Emit ## OP(EmitBinOps(E)); \ 284 } \ 285 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 286 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 287 } 288 HANDLEBINOP(Mul); 289 HANDLEBINOP(Div); 290 HANDLEBINOP(Rem); 291 HANDLEBINOP(Add); 292 HANDLEBINOP(Sub); 293 HANDLEBINOP(Shl); 294 HANDLEBINOP(Shr); 295 HANDLEBINOP(And); 296 HANDLEBINOP(Xor); 297 HANDLEBINOP(Or); 298#undef HANDLEBINOP 299 300 // Comparisons. 301 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 302 unsigned SICmpOpc, unsigned FCmpOpc); 303#define VISITCOMP(CODE, UI, SI, FP) \ 304 Value *VisitBin##CODE(const BinaryOperator *E) { \ 305 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 306 llvm::FCmpInst::FP); } 307 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT); 308 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT); 309 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE); 310 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE); 311 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ); 312 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE); 313#undef VISITCOMP 314 315 Value *VisitBinAssign (const BinaryOperator *E); 316 317 Value *VisitBinLAnd (const BinaryOperator *E); 318 Value *VisitBinLOr (const BinaryOperator *E); 319 Value *VisitBinComma (const BinaryOperator *E); 320 321 // Other Operators. 322 Value *VisitBlockExpr(const BlockExpr *BE); 323 Value *VisitConditionalOperator(const ConditionalOperator *CO); 324 Value *VisitChooseExpr(ChooseExpr *CE); 325 Value *VisitOverloadExpr(OverloadExpr *OE); 326 Value *VisitVAArgExpr(VAArgExpr *VE); 327 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 328 return CGF.EmitObjCStringLiteral(E); 329 } 330 Value *VisitObjCEncodeExpr(const ObjCEncodeExpr *E); 331}; 332} // end anonymous namespace. 333 334//===----------------------------------------------------------------------===// 335// Utilities 336//===----------------------------------------------------------------------===// 337 338/// EmitConversionToBool - Convert the specified expression value to a 339/// boolean (i1) truth value. This is equivalent to "Val != 0". 340Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 341 assert(SrcType->isCanonical() && "EmitScalarConversion strips typedefs"); 342 343 if (SrcType->isRealFloatingType()) { 344 // Compare against 0.0 for fp scalars. 345 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 346 return Builder.CreateFCmpUNE(Src, Zero, "tobool"); 347 } 348 349 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 350 "Unknown scalar type to convert"); 351 352 // Because of the type rules of C, we often end up computing a logical value, 353 // then zero extending it to int, then wanting it as a logical value again. 354 // Optimize this common case. 355 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) { 356 if (ZI->getOperand(0)->getType() == llvm::Type::Int1Ty) { 357 Value *Result = ZI->getOperand(0); 358 // If there aren't any more uses, zap the instruction to save space. 359 // Note that there can be more uses, for example if this 360 // is the result of an assignment. 361 if (ZI->use_empty()) 362 ZI->eraseFromParent(); 363 return Result; 364 } 365 } 366 367 // Compare against an integer or pointer null. 368 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 369 return Builder.CreateICmpNE(Src, Zero, "tobool"); 370} 371 372/// EmitScalarConversion - Emit a conversion from the specified type to the 373/// specified destination type, both of which are LLVM scalar types. 374Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 375 QualType DstType) { 376 SrcType = CGF.getContext().getCanonicalType(SrcType); 377 DstType = CGF.getContext().getCanonicalType(DstType); 378 if (SrcType == DstType) return Src; 379 380 if (DstType->isVoidType()) return 0; 381 382 // Handle conversions to bool first, they are special: comparisons against 0. 383 if (DstType->isBooleanType()) 384 return EmitConversionToBool(Src, SrcType); 385 386 const llvm::Type *DstTy = ConvertType(DstType); 387 388 // Ignore conversions like int -> uint. 389 if (Src->getType() == DstTy) 390 return Src; 391 392 // Handle pointer conversions next: pointers can only be converted 393 // to/from other pointers and integers. Check for pointer types in 394 // terms of LLVM, as some native types (like Obj-C id) may map to a 395 // pointer type. 396 if (isa<llvm::PointerType>(DstTy)) { 397 // The source value may be an integer, or a pointer. 398 if (isa<llvm::PointerType>(Src->getType())) 399 return Builder.CreateBitCast(Src, DstTy, "conv"); 400 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 401 return Builder.CreateIntToPtr(Src, DstTy, "conv"); 402 } 403 404 if (isa<llvm::PointerType>(Src->getType())) { 405 // Must be an ptr to int cast. 406 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 407 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 408 } 409 410 // A scalar can be splatted to an extended vector of the same element type 411 if (DstType->isExtVectorType() && !isa<VectorType>(SrcType)) { 412 // Cast the scalar to element type 413 QualType EltTy = DstType->getAsExtVectorType()->getElementType(); 414 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 415 416 // Insert the element in element zero of an undef vector 417 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 418 llvm::Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, 0); 419 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 420 421 // Splat the element across to all elements 422 llvm::SmallVector<llvm::Constant*, 16> Args; 423 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 424 for (unsigned i = 0; i < NumElements; i++) 425 Args.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, 0)); 426 427 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 428 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 429 return Yay; 430 } 431 432 // Allow bitcast from vector to integer/fp of the same size. 433 if (isa<llvm::VectorType>(Src->getType()) || 434 isa<llvm::VectorType>(DstTy)) 435 return Builder.CreateBitCast(Src, DstTy, "conv"); 436 437 // Finally, we have the arithmetic types: real int/float. 438 if (isa<llvm::IntegerType>(Src->getType())) { 439 bool InputSigned = SrcType->isSignedIntegerType(); 440 if (isa<llvm::IntegerType>(DstTy)) 441 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 442 else if (InputSigned) 443 return Builder.CreateSIToFP(Src, DstTy, "conv"); 444 else 445 return Builder.CreateUIToFP(Src, DstTy, "conv"); 446 } 447 448 assert(Src->getType()->isFloatingPoint() && "Unknown real conversion"); 449 if (isa<llvm::IntegerType>(DstTy)) { 450 if (DstType->isSignedIntegerType()) 451 return Builder.CreateFPToSI(Src, DstTy, "conv"); 452 else 453 return Builder.CreateFPToUI(Src, DstTy, "conv"); 454 } 455 456 assert(DstTy->isFloatingPoint() && "Unknown real conversion"); 457 if (DstTy->getTypeID() < Src->getType()->getTypeID()) 458 return Builder.CreateFPTrunc(Src, DstTy, "conv"); 459 else 460 return Builder.CreateFPExt(Src, DstTy, "conv"); 461} 462 463/// EmitComplexToScalarConversion - Emit a conversion from the specified 464/// complex type to the specified destination type, where the destination 465/// type is an LLVM scalar type. 466Value *ScalarExprEmitter:: 467EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 468 QualType SrcTy, QualType DstTy) { 469 // Get the source element type. 470 SrcTy = SrcTy->getAsComplexType()->getElementType(); 471 472 // Handle conversions to bool first, they are special: comparisons against 0. 473 if (DstTy->isBooleanType()) { 474 // Complex != 0 -> (Real != 0) | (Imag != 0) 475 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 476 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 477 return Builder.CreateOr(Src.first, Src.second, "tobool"); 478 } 479 480 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 481 // the imaginary part of the complex value is discarded and the value of the 482 // real part is converted according to the conversion rules for the 483 // corresponding real type. 484 return EmitScalarConversion(Src.first, SrcTy, DstTy); 485} 486 487 488//===----------------------------------------------------------------------===// 489// Visitor Methods 490//===----------------------------------------------------------------------===// 491 492Value *ScalarExprEmitter::VisitExpr(Expr *E) { 493 CGF.ErrorUnsupported(E, "scalar expression"); 494 if (E->getType()->isVoidType()) 495 return 0; 496 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 497} 498 499Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 500 llvm::SmallVector<llvm::Constant*, 32> indices; 501 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 502 indices.push_back(cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i)))); 503 } 504 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 505 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 506 Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); 507 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 508} 509 510Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 511 // Emit subscript expressions in rvalue context's. For most cases, this just 512 // loads the lvalue formed by the subscript expr. However, we have to be 513 // careful, because the base of a vector subscript is occasionally an rvalue, 514 // so we can't get it as an lvalue. 515 if (!E->getBase()->getType()->isVectorType()) 516 return EmitLoadOfLValue(E); 517 518 // Handle the vector case. The base must be a vector, the index must be an 519 // integer value. 520 Value *Base = Visit(E->getBase()); 521 Value *Idx = Visit(E->getIdx()); 522 523 // FIXME: Convert Idx to i32 type. 524 return Builder.CreateExtractElement(Base, Idx, "vecext"); 525} 526 527/// VisitImplicitCastExpr - Implicit casts are the same as normal casts, but 528/// also handle things like function to pointer-to-function decay, and array to 529/// pointer decay. 530Value *ScalarExprEmitter::VisitImplicitCastExpr(const ImplicitCastExpr *E) { 531 const Expr *Op = E->getSubExpr(); 532 533 // If this is due to array->pointer conversion, emit the array expression as 534 // an l-value. 535 if (Op->getType()->isArrayType()) { 536 // FIXME: For now we assume that all source arrays map to LLVM arrays. This 537 // will not true when we add support for VLAs. 538 Value *V = EmitLValue(Op).getAddress(); // Bitfields can't be arrays. 539 540 if (!Op->getType()->isVariableArrayType()) { 541 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 542 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 543 ->getElementType()) && 544 "Expected pointer to array"); 545 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 546 } 547 548 // The resultant pointer type can be implicitly casted to other pointer 549 // types as well (e.g. void*) and can be implicitly converted to integer. 550 const llvm::Type *DestTy = ConvertType(E->getType()); 551 if (V->getType() != DestTy) { 552 if (isa<llvm::PointerType>(DestTy)) 553 V = Builder.CreateBitCast(V, DestTy, "ptrconv"); 554 else { 555 assert(isa<llvm::IntegerType>(DestTy) && "Unknown array decay"); 556 V = Builder.CreatePtrToInt(V, DestTy, "ptrconv"); 557 } 558 } 559 return V; 560 561 } else if (E->getType()->isReferenceType()) { 562 return EmitLValue(Op).getAddress(); 563 } 564 565 return EmitCastExpr(Op, E->getType()); 566} 567 568 569// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 570// have to handle a more broad range of conversions than explicit casts, as they 571// handle things like function to ptr-to-function decay etc. 572Value *ScalarExprEmitter::EmitCastExpr(const Expr *E, QualType DestTy) { 573 // Handle cases where the source is an non-complex type. 574 575 if (!CGF.hasAggregateLLVMType(E->getType())) { 576 Value *Src = Visit(const_cast<Expr*>(E)); 577 578 // Use EmitScalarConversion to perform the conversion. 579 return EmitScalarConversion(Src, E->getType(), DestTy); 580 } 581 582 if (E->getType()->isAnyComplexType()) { 583 // Handle cases where the source is a complex type. 584 return EmitComplexToScalarConversion(CGF.EmitComplexExpr(E), E->getType(), 585 DestTy); 586 } 587 588 // Okay, this is a cast from an aggregate. It must be a cast to void. Just 589 // evaluate the result and return. 590 CGF.EmitAggExpr(E, 0, false); 591 return 0; 592} 593 594Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 595 return CGF.EmitCompoundStmt(*E->getSubStmt(), 596 !E->getType()->isVoidType()).getScalarVal(); 597} 598 599 600//===----------------------------------------------------------------------===// 601// Unary Operators 602//===----------------------------------------------------------------------===// 603 604Value *ScalarExprEmitter::VisitPrePostIncDec(const UnaryOperator *E, 605 bool isInc, bool isPre) { 606 LValue LV = EmitLValue(E->getSubExpr()); 607 // FIXME: Handle volatile! 608 Value *InVal = CGF.EmitLoadOfLValue(LV, // false 609 E->getSubExpr()->getType()).getScalarVal(); 610 611 int AmountVal = isInc ? 1 : -1; 612 613 Value *NextVal; 614 if (isa<llvm::PointerType>(InVal->getType())) { 615 // FIXME: This isn't right for VLAs. 616 NextVal = llvm::ConstantInt::get(llvm::Type::Int32Ty, AmountVal); 617 NextVal = Builder.CreateGEP(InVal, NextVal, "ptrincdec"); 618 } else if (InVal->getType() == llvm::Type::Int1Ty && isInc) { 619 // Bool++ is an interesting case, due to promotion rules, we get: 620 // Bool++ -> Bool = Bool+1 -> Bool = (int)Bool+1 -> 621 // Bool = ((int)Bool+1) != 0 622 // An interesting aspect of this is that increment is always true. 623 // Decrement does not have this property. 624 NextVal = llvm::ConstantInt::getTrue(); 625 } else { 626 // Add the inc/dec to the real part. 627 if (isa<llvm::IntegerType>(InVal->getType())) 628 NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); 629 else if (InVal->getType() == llvm::Type::FloatTy) 630 NextVal = 631 llvm::ConstantFP::get(llvm::APFloat(static_cast<float>(AmountVal))); 632 else if (InVal->getType() == llvm::Type::DoubleTy) 633 NextVal = 634 llvm::ConstantFP::get(llvm::APFloat(static_cast<double>(AmountVal))); 635 else { 636 llvm::APFloat F(static_cast<float>(AmountVal)); 637 bool ignored; 638 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, 639 &ignored); 640 NextVal = llvm::ConstantFP::get(F); 641 } 642 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 643 } 644 645 // Store the updated result through the lvalue. 646 CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV, 647 E->getSubExpr()->getType()); 648 649 // If this is a postinc, return the value read from memory, otherwise use the 650 // updated value. 651 return isPre ? NextVal : InVal; 652} 653 654 655Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 656 Value *Op = Visit(E->getSubExpr()); 657 return Builder.CreateNeg(Op, "neg"); 658} 659 660Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 661 Value *Op = Visit(E->getSubExpr()); 662 return Builder.CreateNot(Op, "neg"); 663} 664 665Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 666 // Compare operand to zero. 667 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 668 669 // Invert value. 670 // TODO: Could dynamically modify easy computations here. For example, if 671 // the operand is an icmp ne, turn into icmp eq. 672 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 673 674 // ZExt result to int. 675 return Builder.CreateZExt(BoolVal, CGF.LLVMIntTy, "lnot.ext"); 676} 677 678/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of 679/// argument of the sizeof expression as an integer. 680Value * 681ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { 682 QualType TypeToSize = E->getTypeOfArgument(); 683 if (E->isSizeOf()) { 684 if (const VariableArrayType *VAT = 685 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 686 if (E->isArgumentType()) { 687 // sizeof(type) - make sure to emit the VLA size. 688 CGF.EmitVLASize(TypeToSize); 689 } 690 691 return CGF.GetVLASize(VAT); 692 } 693 } 694 695 // If this isn't sizeof(vla), the result must be constant; use the 696 // constant folding logic so we don't have to duplicate it here. 697 Expr::EvalResult Result; 698 E->Evaluate(Result, CGF.getContext()); 699 return llvm::ConstantInt::get(Result.Val.getInt()); 700} 701 702Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 703 Expr *Op = E->getSubExpr(); 704 if (Op->getType()->isAnyComplexType()) 705 return CGF.EmitComplexExpr(Op).first; 706 return Visit(Op); 707} 708Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 709 Expr *Op = E->getSubExpr(); 710 if (Op->getType()->isAnyComplexType()) 711 return CGF.EmitComplexExpr(Op).second; 712 713 // __imag on a scalar returns zero. Emit it the subexpr to ensure side 714 // effects are evaluated. 715 CGF.EmitScalarExpr(Op); 716 return llvm::Constant::getNullValue(ConvertType(E->getType())); 717} 718 719Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) 720{ 721 const Expr* SubExpr = E->getSubExpr(); 722 const llvm::Type* ResultType = ConvertType(E->getType()); 723 llvm::Value* Result = llvm::Constant::getNullValue(ResultType); 724 while (!isa<CompoundLiteralExpr>(SubExpr)) { 725 if (const MemberExpr *ME = dyn_cast<MemberExpr>(SubExpr)) { 726 SubExpr = ME->getBase(); 727 QualType Ty = SubExpr->getType(); 728 729 RecordDecl *RD = Ty->getAsRecordType()->getDecl(); 730 const ASTRecordLayout &RL = CGF.getContext().getASTRecordLayout(RD); 731 FieldDecl *FD = cast<FieldDecl>(ME->getMemberDecl()); 732 733 // FIXME: This is linear time. And the fact that we're indexing 734 // into the layout by position in the record means that we're 735 // either stuck numbering the fields in the AST or we have to keep 736 // the linear search (yuck and yuck). 737 unsigned i = 0; 738 for (RecordDecl::field_iterator Field = RD->field_begin(), 739 FieldEnd = RD->field_end(); 740 Field != FieldEnd; (void)++Field, ++i) { 741 if (*Field == FD) 742 break; 743 } 744 745 llvm::Value* Offset = 746 llvm::ConstantInt::get(ResultType, RL.getFieldOffset(i) / 8); 747 Result = Builder.CreateAdd(Result, Offset); 748 } else if (const ArraySubscriptExpr *ASE = dyn_cast<ArraySubscriptExpr>(SubExpr)) { 749 SubExpr = ASE->getBase(); 750 int64_t size = CGF.getContext().getTypeSize(ASE->getType()) / 8; 751 llvm::Value* ElemSize = llvm::ConstantInt::get(ResultType, size); 752 llvm::Value* ElemIndex = CGF.EmitScalarExpr(ASE->getIdx()); 753 bool IndexSigned = ASE->getIdx()->getType()->isSignedIntegerType(); 754 ElemIndex = Builder.CreateIntCast(ElemIndex, ResultType, IndexSigned); 755 llvm::Value* Offset = Builder.CreateMul(ElemSize, ElemIndex); 756 Result = Builder.CreateAdd(Result, Offset); 757 } else { 758 assert(0 && "This should be impossible!"); 759 } 760 } 761 return Result; 762} 763 764//===----------------------------------------------------------------------===// 765// Binary Operators 766//===----------------------------------------------------------------------===// 767 768BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 769 BinOpInfo Result; 770 Result.LHS = Visit(E->getLHS()); 771 Result.RHS = Visit(E->getRHS()); 772 Result.Ty = E->getType(); 773 Result.E = E; 774 return Result; 775} 776 777Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 778 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 779 QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType(); 780 781 BinOpInfo OpInfo; 782 783 // Load the LHS and RHS operands. 784 LValue LHSLV = EmitLValue(E->getLHS()); 785 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 786 787 // Determine the computation type. If the RHS is complex, then this is one of 788 // the add/sub/mul/div operators. All of these operators can be computed in 789 // with just their real component even though the computation domain really is 790 // complex. 791 QualType ComputeType = E->getComputationType(); 792 793 // If the computation type is complex, then the RHS is complex. Emit the RHS. 794 if (const ComplexType *CT = ComputeType->getAsComplexType()) { 795 ComputeType = CT->getElementType(); 796 797 // Emit the RHS, only keeping the real component. 798 OpInfo.RHS = CGF.EmitComplexExpr(E->getRHS()).first; 799 RHSTy = RHSTy->getAsComplexType()->getElementType(); 800 } else { 801 // Otherwise the RHS is a simple scalar value. 802 OpInfo.RHS = Visit(E->getRHS()); 803 } 804 805 QualType LComputeTy, RComputeTy, ResultTy; 806 807 // Compound assignment does not contain enough information about all 808 // the types involved for pointer arithmetic cases. Figure it out 809 // here for now. 810 if (E->getLHS()->getType()->isPointerType()) { 811 // Pointer arithmetic cases: ptr +=,-= int and ptr -= ptr, 812 assert((E->getOpcode() == BinaryOperator::AddAssign || 813 E->getOpcode() == BinaryOperator::SubAssign) && 814 "Invalid compound assignment operator on pointer type."); 815 LComputeTy = E->getLHS()->getType(); 816 817 if (E->getRHS()->getType()->isPointerType()) { 818 // Degenerate case of (ptr -= ptr) allowed by GCC implicit cast 819 // extension, the conversion from the pointer difference back to 820 // the LHS type is handled at the end. 821 assert(E->getOpcode() == BinaryOperator::SubAssign && 822 "Invalid compound assignment operator on pointer type."); 823 RComputeTy = E->getLHS()->getType(); 824 ResultTy = CGF.getContext().getPointerDiffType(); 825 } else { 826 RComputeTy = E->getRHS()->getType(); 827 ResultTy = LComputeTy; 828 } 829 } else if (E->getRHS()->getType()->isPointerType()) { 830 // Degenerate case of (int += ptr) allowed by GCC implicit cast 831 // extension. 832 assert(E->getOpcode() == BinaryOperator::AddAssign && 833 "Invalid compound assignment operator on pointer type."); 834 LComputeTy = E->getLHS()->getType(); 835 RComputeTy = E->getRHS()->getType(); 836 ResultTy = RComputeTy; 837 } else { 838 LComputeTy = RComputeTy = ResultTy = ComputeType; 839 } 840 841 // Convert the LHS/RHS values to the computation type. 842 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, LComputeTy); 843 OpInfo.RHS = EmitScalarConversion(OpInfo.RHS, RHSTy, RComputeTy); 844 OpInfo.Ty = ResultTy; 845 OpInfo.E = E; 846 847 // Expand the binary operator. 848 Value *Result = (this->*Func)(OpInfo); 849 850 // Convert the result back to the LHS type. 851 Result = EmitScalarConversion(Result, ResultTy, LHSTy); 852 853 // Store the result value into the LHS lvalue. Bit-fields are 854 // handled specially because the result is altered by the store, 855 // i.e., [C99 6.5.16p1] 'An assignment expression has the value of 856 // the left operand after the assignment...'. 857 if (LHSLV.isBitfield()) 858 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, 859 &Result); 860 else 861 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); 862 863 return Result; 864} 865 866 867Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 868 if (Ops.LHS->getType()->isFPOrFPVector()) 869 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 870 else if (Ops.Ty->isUnsignedIntegerType()) 871 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 872 else 873 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 874} 875 876Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 877 // Rem in C can't be a floating point type: C99 6.5.5p2. 878 if (Ops.Ty->isUnsignedIntegerType()) 879 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 880 else 881 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 882} 883 884 885Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 886 if (!Ops.Ty->isPointerType()) 887 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 888 889 // FIXME: What about a pointer to a VLA? 890 Value *Ptr, *Idx; 891 Expr *IdxExp; 892 const PointerType *PT; 893 if ((PT = Ops.E->getLHS()->getType()->getAsPointerType())) { 894 Ptr = Ops.LHS; 895 Idx = Ops.RHS; 896 IdxExp = Ops.E->getRHS(); 897 } else { // int + pointer 898 PT = Ops.E->getRHS()->getType()->getAsPointerType(); 899 assert(PT && "Invalid add expr"); 900 Ptr = Ops.RHS; 901 Idx = Ops.LHS; 902 IdxExp = Ops.E->getLHS(); 903 } 904 905 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 906 if (Width < CGF.LLVMPointerWidth) { 907 // Zero or sign extend the pointer value based on whether the index is 908 // signed or not. 909 const llvm::Type *IdxType = llvm::IntegerType::get(CGF.LLVMPointerWidth); 910 if (IdxExp->getType()->isSignedIntegerType()) 911 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 912 else 913 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 914 } 915 916 // Explicitly handle GNU void* and function pointer arithmetic 917 // extensions. The GNU void* casts amount to no-ops since our void* 918 // type is i8*, but this is future proof. 919 const QualType ElementType = PT->getPointeeType(); 920 if (ElementType->isVoidType() || ElementType->isFunctionType()) { 921 const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); 922 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 923 Value *Res = Builder.CreateGEP(Casted, Idx, "sub.ptr"); 924 return Builder.CreateBitCast(Res, Ptr->getType()); 925 } 926 927 return Builder.CreateGEP(Ptr, Idx, "add.ptr"); 928} 929 930Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 931 if (!isa<llvm::PointerType>(Ops.LHS->getType())) 932 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 933 934 const QualType LHSType = Ops.E->getLHS()->getType(); 935 const QualType LHSElementType = LHSType->getAsPointerType()->getPointeeType(); 936 if (!isa<llvm::PointerType>(Ops.RHS->getType())) { 937 // pointer - int 938 Value *Idx = Ops.RHS; 939 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 940 if (Width < CGF.LLVMPointerWidth) { 941 // Zero or sign extend the pointer value based on whether the index is 942 // signed or not. 943 const llvm::Type *IdxType = llvm::IntegerType::get(CGF.LLVMPointerWidth); 944 if (Ops.E->getRHS()->getType()->isSignedIntegerType()) 945 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 946 else 947 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 948 } 949 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); 950 951 // FIXME: The pointer could point to a VLA. 952 953 // Explicitly handle GNU void* and function pointer arithmetic 954 // extensions. The GNU void* casts amount to no-ops since our 955 // void* type is i8*, but this is future proof. 956 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 957 const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); 958 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 959 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); 960 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 961 } 962 963 return Builder.CreateGEP(Ops.LHS, Idx, "sub.ptr"); 964 } else { 965 // pointer - pointer 966 Value *LHS = Ops.LHS; 967 Value *RHS = Ops.RHS; 968 969 uint64_t ElementSize; 970 971 // Handle GCC extension for pointer arithmetic on void* and function pointer 972 // types. 973 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 974 ElementSize = 1; 975 } else { 976 ElementSize = CGF.getContext().getTypeSize(LHSElementType) / 8; 977 } 978 979 const llvm::Type *ResultType = ConvertType(Ops.Ty); 980 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 981 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 982 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 983 984 // Optimize out the shift for element size of 1. 985 if (ElementSize == 1) 986 return BytesBetween; 987 988 // HACK: LLVM doesn't have an divide instruction that 'knows' there is no 989 // remainder. As such, we handle common power-of-two cases here to generate 990 // better code. See PR2247. 991 if (llvm::isPowerOf2_64(ElementSize)) { 992 Value *ShAmt = 993 llvm::ConstantInt::get(ResultType, llvm::Log2_64(ElementSize)); 994 return Builder.CreateAShr(BytesBetween, ShAmt, "sub.ptr.shr"); 995 } 996 997 // Otherwise, do a full sdiv. 998 Value *BytesPerElt = llvm::ConstantInt::get(ResultType, ElementSize); 999 return Builder.CreateSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 1000 } 1001} 1002 1003Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 1004 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1005 // RHS to the same size as the LHS. 1006 Value *RHS = Ops.RHS; 1007 if (Ops.LHS->getType() != RHS->getType()) 1008 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1009 1010 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 1011} 1012 1013Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 1014 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 1015 // RHS to the same size as the LHS. 1016 Value *RHS = Ops.RHS; 1017 if (Ops.LHS->getType() != RHS->getType()) 1018 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 1019 1020 if (Ops.Ty->isUnsignedIntegerType()) 1021 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 1022 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 1023} 1024 1025Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 1026 unsigned SICmpOpc, unsigned FCmpOpc) { 1027 Value *Result; 1028 QualType LHSTy = E->getLHS()->getType(); 1029 if (!LHSTy->isAnyComplexType() && !LHSTy->isVectorType()) { 1030 Value *LHS = Visit(E->getLHS()); 1031 Value *RHS = Visit(E->getRHS()); 1032 1033 if (LHS->getType()->isFloatingPoint()) { 1034 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 1035 LHS, RHS, "cmp"); 1036 } else if (LHSTy->isSignedIntegerType()) { 1037 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 1038 LHS, RHS, "cmp"); 1039 } else { 1040 // Unsigned integers and pointers. 1041 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1042 LHS, RHS, "cmp"); 1043 } 1044 } else if (LHSTy->isVectorType()) { 1045 Value *LHS = Visit(E->getLHS()); 1046 Value *RHS = Visit(E->getRHS()); 1047 1048 if (LHS->getType()->isFPOrFPVector()) { 1049 Result = Builder.CreateVFCmp((llvm::CmpInst::Predicate)FCmpOpc, 1050 LHS, RHS, "cmp"); 1051 } else if (LHSTy->isUnsignedIntegerType()) { 1052 Result = Builder.CreateVICmp((llvm::CmpInst::Predicate)UICmpOpc, 1053 LHS, RHS, "cmp"); 1054 } else { 1055 // Signed integers and pointers. 1056 Result = Builder.CreateVICmp((llvm::CmpInst::Predicate)SICmpOpc, 1057 LHS, RHS, "cmp"); 1058 } 1059 return Result; 1060 } else { 1061 // Complex Comparison: can only be an equality comparison. 1062 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 1063 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 1064 1065 QualType CETy = LHSTy->getAsComplexType()->getElementType(); 1066 1067 Value *ResultR, *ResultI; 1068 if (CETy->isRealFloatingType()) { 1069 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1070 LHS.first, RHS.first, "cmp.r"); 1071 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1072 LHS.second, RHS.second, "cmp.i"); 1073 } else { 1074 // Complex comparisons can only be equality comparisons. As such, signed 1075 // and unsigned opcodes are the same. 1076 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1077 LHS.first, RHS.first, "cmp.r"); 1078 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1079 LHS.second, RHS.second, "cmp.i"); 1080 } 1081 1082 if (E->getOpcode() == BinaryOperator::EQ) { 1083 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 1084 } else { 1085 assert(E->getOpcode() == BinaryOperator::NE && 1086 "Complex comparison other than == or != ?"); 1087 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 1088 } 1089 } 1090 1091 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 1092} 1093 1094Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 1095 LValue LHS = EmitLValue(E->getLHS()); 1096 Value *RHS = Visit(E->getRHS()); 1097 1098 // Store the value into the LHS. Bit-fields are handled specially 1099 // because the result is altered by the store, i.e., [C99 6.5.16p1] 1100 // 'An assignment expression has the value of the left operand after 1101 // the assignment...'. 1102 // FIXME: Volatility! 1103 if (LHS.isBitfield()) 1104 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), 1105 &RHS); 1106 else 1107 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 1108 1109 // Return the RHS. 1110 return RHS; 1111} 1112 1113Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 1114 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 1115 // If we have 1 && X, just emit X without inserting the control flow. 1116 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1117 if (Cond == 1) { // If we have 1 && X, just emit X. 1118 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1119 // ZExt result to int. 1120 return Builder.CreateZExt(RHSCond, CGF.LLVMIntTy, "land.ext"); 1121 } 1122 1123 // 0 && RHS: If it is safe, just elide the RHS, and return 0. 1124 if (!CGF.ContainsLabel(E->getRHS())) 1125 return llvm::Constant::getNullValue(CGF.LLVMIntTy); 1126 } 1127 1128 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 1129 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 1130 1131 // Branch on the LHS first. If it is false, go to the failure (cont) block. 1132 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 1133 1134 // Any edges into the ContBlock are now from an (indeterminate number of) 1135 // edges from this first condition. All of these values will be false. Start 1136 // setting up the PHI node in the Cont Block for this. 1137 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::Int1Ty, "", ContBlock); 1138 PN->reserveOperandSpace(2); // Normal case, two inputs. 1139 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1140 PI != PE; ++PI) 1141 PN->addIncoming(llvm::ConstantInt::getFalse(), *PI); 1142 1143 CGF.EmitBlock(RHSBlock); 1144 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1145 1146 // Reaquire the RHS block, as there may be subblocks inserted. 1147 RHSBlock = Builder.GetInsertBlock(); 1148 1149 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1150 // into the phi node for the edge with the value of RHSCond. 1151 CGF.EmitBlock(ContBlock); 1152 PN->addIncoming(RHSCond, RHSBlock); 1153 1154 // ZExt result to int. 1155 return Builder.CreateZExt(PN, CGF.LLVMIntTy, "land.ext"); 1156} 1157 1158Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 1159 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 1160 // If we have 0 || X, just emit X without inserting the control flow. 1161 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1162 if (Cond == -1) { // If we have 0 || X, just emit X. 1163 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1164 // ZExt result to int. 1165 return Builder.CreateZExt(RHSCond, CGF.LLVMIntTy, "lor.ext"); 1166 } 1167 1168 // 1 || RHS: If it is safe, just elide the RHS, and return 1. 1169 if (!CGF.ContainsLabel(E->getRHS())) 1170 return llvm::ConstantInt::get(CGF.LLVMIntTy, 1); 1171 } 1172 1173 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 1174 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 1175 1176 // Branch on the LHS first. If it is true, go to the success (cont) block. 1177 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 1178 1179 // Any edges into the ContBlock are now from an (indeterminate number of) 1180 // edges from this first condition. All of these values will be true. Start 1181 // setting up the PHI node in the Cont Block for this. 1182 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::Int1Ty, "", ContBlock); 1183 PN->reserveOperandSpace(2); // Normal case, two inputs. 1184 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1185 PI != PE; ++PI) 1186 PN->addIncoming(llvm::ConstantInt::getTrue(), *PI); 1187 1188 // Emit the RHS condition as a bool value. 1189 CGF.EmitBlock(RHSBlock); 1190 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1191 1192 // Reaquire the RHS block, as there may be subblocks inserted. 1193 RHSBlock = Builder.GetInsertBlock(); 1194 1195 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1196 // into the phi node for the edge with the value of RHSCond. 1197 CGF.EmitBlock(ContBlock); 1198 PN->addIncoming(RHSCond, RHSBlock); 1199 1200 // ZExt result to int. 1201 return Builder.CreateZExt(PN, CGF.LLVMIntTy, "lor.ext"); 1202} 1203 1204Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 1205 CGF.EmitStmt(E->getLHS()); 1206 CGF.EnsureInsertPoint(); 1207 return Visit(E->getRHS()); 1208} 1209 1210//===----------------------------------------------------------------------===// 1211// Other Operators 1212//===----------------------------------------------------------------------===// 1213 1214/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 1215/// expression is cheap enough and side-effect-free enough to evaluate 1216/// unconditionally instead of conditionally. This is used to convert control 1217/// flow into selects in some cases. 1218static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E) { 1219 if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) 1220 return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr()); 1221 1222 // TODO: Allow anything we can constant fold to an integer or fp constant. 1223 if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || 1224 isa<FloatingLiteral>(E)) 1225 return true; 1226 1227 // Non-volatile automatic variables too, to get "cond ? X : Y" where 1228 // X and Y are local variables. 1229 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 1230 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 1231 if (VD->hasLocalStorage() && !VD->getType().isVolatileQualified()) 1232 return true; 1233 1234 return false; 1235} 1236 1237 1238Value *ScalarExprEmitter:: 1239VisitConditionalOperator(const ConditionalOperator *E) { 1240 // If the condition constant folds and can be elided, try to avoid emitting 1241 // the condition and the dead arm. 1242 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ 1243 Expr *Live = E->getLHS(), *Dead = E->getRHS(); 1244 if (Cond == -1) 1245 std::swap(Live, Dead); 1246 1247 // If the dead side doesn't have labels we need, and if the Live side isn't 1248 // the gnu missing ?: extension (which we could handle, but don't bother 1249 // to), just emit the Live part. 1250 if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part 1251 Live) // Live part isn't missing. 1252 return Visit(Live); 1253 } 1254 1255 1256 // If this is a really simple expression (like x ? 4 : 5), emit this as a 1257 // select instead of as control flow. We can only do this if it is cheap and 1258 // safe to evaluate the LHS and RHS unconditionally. 1259 if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS()) && 1260 isCheapEnoughToEvaluateUnconditionally(E->getRHS())) { 1261 llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); 1262 llvm::Value *LHS = Visit(E->getLHS()); 1263 llvm::Value *RHS = Visit(E->getRHS()); 1264 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 1265 } 1266 1267 1268 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 1269 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 1270 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 1271 Value *CondVal = 0; 1272 1273 // If we don't have the GNU missing condition extension, emit a branch on 1274 // bool the normal way. 1275 if (E->getLHS()) { 1276 // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for 1277 // the branch on bool. 1278 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); 1279 } else { 1280 // Otherwise, for the ?: extension, evaluate the conditional and then 1281 // convert it to bool the hard way. We do this explicitly because we need 1282 // the unconverted value for the missing middle value of the ?:. 1283 CondVal = CGF.EmitScalarExpr(E->getCond()); 1284 1285 // In some cases, EmitScalarConversion will delete the "CondVal" expression 1286 // if there are no extra uses (an optimization). Inhibit this by making an 1287 // extra dead use, because we're going to add a use of CondVal later. We 1288 // don't use the builder for this, because we don't want it to get optimized 1289 // away. This leaves dead code, but the ?: extension isn't common. 1290 new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", 1291 Builder.GetInsertBlock()); 1292 1293 Value *CondBoolVal = 1294 CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 1295 CGF.getContext().BoolTy); 1296 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 1297 } 1298 1299 CGF.EmitBlock(LHSBlock); 1300 1301 // Handle the GNU extension for missing LHS. 1302 Value *LHS; 1303 if (E->getLHS()) 1304 LHS = Visit(E->getLHS()); 1305 else // Perform promotions, to handle cases like "short ?: int" 1306 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); 1307 1308 LHSBlock = Builder.GetInsertBlock(); 1309 CGF.EmitBranch(ContBlock); 1310 1311 CGF.EmitBlock(RHSBlock); 1312 1313 Value *RHS = Visit(E->getRHS()); 1314 RHSBlock = Builder.GetInsertBlock(); 1315 CGF.EmitBranch(ContBlock); 1316 1317 CGF.EmitBlock(ContBlock); 1318 1319 if (!LHS || !RHS) { 1320 assert(E->getType()->isVoidType() && "Non-void value should have a value"); 1321 return 0; 1322 } 1323 1324 // Create a PHI node for the real part. 1325 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 1326 PN->reserveOperandSpace(2); 1327 PN->addIncoming(LHS, LHSBlock); 1328 PN->addIncoming(RHS, RHSBlock); 1329 return PN; 1330} 1331 1332Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 1333 // Emit the LHS or RHS as appropriate. 1334 return 1335 Visit(E->isConditionTrue(CGF.getContext()) ? E->getLHS() : E->getRHS()); 1336} 1337 1338Value *ScalarExprEmitter::VisitOverloadExpr(OverloadExpr *E) { 1339 return CGF.EmitCallExpr(E->getFn(), E->arg_begin(), 1340 E->arg_end(CGF.getContext())).getScalarVal(); 1341} 1342 1343Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 1344 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 1345 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 1346 1347 // If EmitVAArg fails, we fall back to the LLVM instruction. 1348 if (!ArgPtr) 1349 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 1350 1351 // FIXME: volatile? 1352 return Builder.CreateLoad(ArgPtr); 1353} 1354 1355Value *ScalarExprEmitter::VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { 1356 std::string str; 1357 CGF.getContext().getObjCEncodingForType(E->getEncodedType(), str); 1358 1359 llvm::Constant *C = llvm::ConstantArray::get(str); 1360 C = new llvm::GlobalVariable(C->getType(), true, 1361 llvm::GlobalValue::InternalLinkage, 1362 C, ".str", &CGF.CGM.getModule()); 1363 llvm::Constant *Zero = llvm::Constant::getNullValue(llvm::Type::Int32Ty); 1364 llvm::Constant *Zeros[] = { Zero, Zero }; 1365 C = llvm::ConstantExpr::getGetElementPtr(C, Zeros, 2); 1366 1367 return C; 1368} 1369 1370 1371Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { 1372 llvm::Constant *C = CGF.BuildBlockLiteralTmp(); 1373 1374 const llvm::PointerType *PtrToInt8Ty 1375 = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); 1376 return llvm::ConstantExpr::getBitCast(C, PtrToInt8Ty); 1377} 1378 1379//===----------------------------------------------------------------------===// 1380// Entry Point into this File 1381//===----------------------------------------------------------------------===// 1382 1383/// EmitComplexExpr - Emit the computation of the specified expression of 1384/// complex type, ignoring the result. 1385Value *CodeGenFunction::EmitScalarExpr(const Expr *E) { 1386 assert(E && !hasAggregateLLVMType(E->getType()) && 1387 "Invalid scalar expression to emit"); 1388 1389 return ScalarExprEmitter(*this).Visit(const_cast<Expr*>(E)); 1390} 1391 1392/// EmitScalarConversion - Emit a conversion from the specified type to the 1393/// specified destination type, both of which are LLVM scalar types. 1394Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 1395 QualType DstTy) { 1396 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 1397 "Invalid scalar expression to emit"); 1398 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 1399} 1400 1401/// EmitComplexToScalarConversion - Emit a conversion from the specified 1402/// complex type to the specified destination type, where the destination 1403/// type is an LLVM scalar type. 1404Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 1405 QualType SrcTy, 1406 QualType DstTy) { 1407 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 1408 "Invalid complex -> scalar conversion"); 1409 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 1410 DstTy); 1411} 1412 1413Value *CodeGenFunction::EmitShuffleVector(Value* V1, Value *V2, ...) { 1414 assert(V1->getType() == V2->getType() && 1415 "Vector operands must be of the same type"); 1416 unsigned NumElements = 1417 cast<llvm::VectorType>(V1->getType())->getNumElements(); 1418 1419 va_list va; 1420 va_start(va, V2); 1421 1422 llvm::SmallVector<llvm::Constant*, 16> Args; 1423 for (unsigned i = 0; i < NumElements; i++) { 1424 int n = va_arg(va, int); 1425 assert(n >= 0 && n < (int)NumElements * 2 && 1426 "Vector shuffle index out of bounds!"); 1427 Args.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, n)); 1428 } 1429 1430 const char *Name = va_arg(va, const char *); 1431 va_end(va); 1432 1433 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 1434 1435 return Builder.CreateShuffleVector(V1, V2, Mask, Name); 1436} 1437 1438llvm::Value *CodeGenFunction::EmitVector(llvm::Value * const *Vals, 1439 unsigned NumVals, bool isSplat) { 1440 llvm::Value *Vec 1441 = llvm::UndefValue::get(llvm::VectorType::get(Vals[0]->getType(), NumVals)); 1442 1443 for (unsigned i = 0, e = NumVals; i != e; ++i) { 1444 llvm::Value *Val = isSplat ? Vals[0] : Vals[i]; 1445 llvm::Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); 1446 Vec = Builder.CreateInsertElement(Vec, Val, Idx, "tmp"); 1447 } 1448 1449 return Vec; 1450} 1451