CGExprScalar.cpp revision 662174c82ef46b19a2329c7d37208e1d12dfb7b3
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/StmtVisitor.h" 19#include "clang/Basic/TargetInfo.h" 20#include "llvm/Constants.h" 21#include "llvm/Function.h" 22#include "llvm/GlobalVariable.h" 23#include "llvm/Intrinsics.h" 24#include "llvm/Support/Compiler.h" 25#include <cstdarg> 26 27using namespace clang; 28using namespace CodeGen; 29using llvm::Value; 30 31//===----------------------------------------------------------------------===// 32// Scalar Expression Emitter 33//===----------------------------------------------------------------------===// 34 35struct BinOpInfo { 36 Value *LHS; 37 Value *RHS; 38 QualType Ty; // Computation Type. 39 const BinaryOperator *E; 40}; 41 42namespace { 43class VISIBILITY_HIDDEN ScalarExprEmitter 44 : public StmtVisitor<ScalarExprEmitter, Value*> { 45 CodeGenFunction &CGF; 46 llvm::IRBuilder<> &Builder; 47 48public: 49 50 ScalarExprEmitter(CodeGenFunction &cgf) : CGF(cgf), 51 Builder(CGF.Builder) { 52 } 53 54 //===--------------------------------------------------------------------===// 55 // Utilities 56 //===--------------------------------------------------------------------===// 57 58 const llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); } 59 LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); } 60 61 Value *EmitLoadOfLValue(LValue LV, QualType T) { 62 return CGF.EmitLoadOfLValue(LV, T).getScalarVal(); 63 } 64 65 /// EmitLoadOfLValue - Given an expression with complex type that represents a 66 /// value l-value, this method emits the address of the l-value, then loads 67 /// and returns the result. 68 Value *EmitLoadOfLValue(const Expr *E) { 69 // FIXME: Volatile 70 return EmitLoadOfLValue(EmitLValue(E), E->getType()); 71 } 72 73 /// EmitConversionToBool - Convert the specified expression value to a 74 /// boolean (i1) truth value. This is equivalent to "Val != 0". 75 Value *EmitConversionToBool(Value *Src, QualType DstTy); 76 77 /// EmitScalarConversion - Emit a conversion from the specified type to the 78 /// specified destination type, both of which are LLVM scalar types. 79 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); 80 81 /// EmitComplexToScalarConversion - Emit a conversion from the specified 82 /// complex type to the specified destination type, where the destination 83 /// type is an LLVM scalar type. 84 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 85 QualType SrcTy, QualType DstTy); 86 87 //===--------------------------------------------------------------------===// 88 // Visitor Methods 89 //===--------------------------------------------------------------------===// 90 91 Value *VisitStmt(Stmt *S) { 92 S->dump(CGF.getContext().getSourceManager()); 93 assert(0 && "Stmt can't have complex result type!"); 94 return 0; 95 } 96 Value *VisitExpr(Expr *S); 97 Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); } 98 99 // Leaves. 100 Value *VisitIntegerLiteral(const IntegerLiteral *E) { 101 return llvm::ConstantInt::get(E->getValue()); 102 } 103 Value *VisitFloatingLiteral(const FloatingLiteral *E) { 104 return llvm::ConstantFP::get(E->getValue()); 105 } 106 Value *VisitCharacterLiteral(const CharacterLiteral *E) { 107 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 108 } 109 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 110 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 111 } 112 Value *VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) { 113 return llvm::Constant::getNullValue(ConvertType(E->getType())); 114 } 115 Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { 116 return llvm::ConstantInt::get(ConvertType(E->getType()), 117 CGF.getContext().typesAreCompatible( 118 E->getArgType1(), E->getArgType2())); 119 } 120 Value *VisitSizeOfAlignOfTypeExpr(const SizeOfAlignOfTypeExpr *E) { 121 return EmitSizeAlignOf(E->getArgumentType(), E->getType(), E->isSizeOf()); 122 } 123 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 124 llvm::Value *V = 125 llvm::ConstantInt::get(llvm::Type::Int32Ty, 126 CGF.GetIDForAddrOfLabel(E->getLabel())); 127 128 return Builder.CreateIntToPtr(V, ConvertType(E->getType())); 129 } 130 131 // l-values. 132 Value *VisitDeclRefExpr(DeclRefExpr *E) { 133 if (const EnumConstantDecl *EC = dyn_cast<EnumConstantDecl>(E->getDecl())) 134 return llvm::ConstantInt::get(EC->getInitVal()); 135 return EmitLoadOfLValue(E); 136 } 137 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 138 return CGF.EmitObjCSelectorExpr(E); 139 } 140 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 141 return CGF.EmitObjCProtocolExpr(E); 142 } 143 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 144 return EmitLoadOfLValue(E); 145 } 146 Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { 147 return EmitLoadOfLValue(E); 148 } 149 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 150 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 151 } 152 153 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 154 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 155 Value *VisitMemberExpr(Expr *E) { return EmitLoadOfLValue(E); } 156 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 157 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { return EmitLoadOfLValue(E); } 158 Value *VisitStringLiteral(Expr *E) { return EmitLValue(E).getAddress(); } 159 Value *VisitPredefinedExpr(Expr *E) { return EmitLValue(E).getAddress(); } 160 161 Value *VisitInitListExpr(InitListExpr *E) { 162 unsigned NumInitElements = E->getNumInits(); 163 164 const llvm::VectorType *VType = 165 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 166 167 // We have a scalar in braces. Just use the first element. 168 if (!VType) 169 return Visit(E->getInit(0)); 170 171 unsigned NumVectorElements = VType->getNumElements(); 172 const llvm::Type *ElementType = VType->getElementType(); 173 174 // Emit individual vector element stores. 175 llvm::Value *V = llvm::UndefValue::get(VType); 176 177 // Emit initializers 178 unsigned i; 179 for (i = 0; i < NumInitElements; ++i) { 180 Value *NewV = Visit(E->getInit(i)); 181 Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); 182 V = Builder.CreateInsertElement(V, NewV, Idx); 183 } 184 185 // Emit remaining default initializers 186 for (/* Do not initialize i*/; i < NumVectorElements; ++i) { 187 Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); 188 llvm::Value *NewV = llvm::Constant::getNullValue(ElementType); 189 V = Builder.CreateInsertElement(V, NewV, Idx); 190 } 191 192 return V; 193 } 194 195 Value *VisitImplicitCastExpr(const ImplicitCastExpr *E); 196 Value *VisitCastExpr(const CastExpr *E) { 197 return EmitCastExpr(E->getSubExpr(), E->getType()); 198 } 199 Value *EmitCastExpr(const Expr *E, QualType T); 200 201 Value *VisitCallExpr(const CallExpr *E) { 202 return CGF.EmitCallExpr(E).getScalarVal(); 203 } 204 205 Value *VisitStmtExpr(const StmtExpr *E); 206 207 // Unary Operators. 208 Value *VisitPrePostIncDec(const UnaryOperator *E, bool isInc, bool isPre); 209 Value *VisitUnaryPostDec(const UnaryOperator *E) { 210 return VisitPrePostIncDec(E, false, false); 211 } 212 Value *VisitUnaryPostInc(const UnaryOperator *E) { 213 return VisitPrePostIncDec(E, true, false); 214 } 215 Value *VisitUnaryPreDec(const UnaryOperator *E) { 216 return VisitPrePostIncDec(E, false, true); 217 } 218 Value *VisitUnaryPreInc(const UnaryOperator *E) { 219 return VisitPrePostIncDec(E, true, true); 220 } 221 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 222 return EmitLValue(E->getSubExpr()).getAddress(); 223 } 224 Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } 225 Value *VisitUnaryPlus(const UnaryOperator *E) { 226 return Visit(E->getSubExpr()); 227 } 228 Value *VisitUnaryMinus (const UnaryOperator *E); 229 Value *VisitUnaryNot (const UnaryOperator *E); 230 Value *VisitUnaryLNot (const UnaryOperator *E); 231 Value *VisitUnarySizeOf (const UnaryOperator *E) { 232 return EmitSizeAlignOf(E->getSubExpr()->getType(), E->getType(), true); 233 } 234 Value *VisitUnaryAlignOf (const UnaryOperator *E) { 235 return EmitSizeAlignOf(E->getSubExpr()->getType(), E->getType(), false); 236 } 237 Value *EmitSizeAlignOf(QualType TypeToSize, QualType RetType, 238 bool isSizeOf); 239 Value *VisitUnaryReal (const UnaryOperator *E); 240 Value *VisitUnaryImag (const UnaryOperator *E); 241 Value *VisitUnaryExtension(const UnaryOperator *E) { 242 return Visit(E->getSubExpr()); 243 } 244 Value *VisitUnaryOffsetOf(const UnaryOperator *E); 245 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 246 return Visit(DAE->getExpr()); 247 } 248 249 // Binary Operators. 250 Value *EmitMul(const BinOpInfo &Ops) { 251 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 252 } 253 Value *EmitDiv(const BinOpInfo &Ops); 254 Value *EmitRem(const BinOpInfo &Ops); 255 Value *EmitAdd(const BinOpInfo &Ops); 256 Value *EmitSub(const BinOpInfo &Ops); 257 Value *EmitShl(const BinOpInfo &Ops); 258 Value *EmitShr(const BinOpInfo &Ops); 259 Value *EmitAnd(const BinOpInfo &Ops) { 260 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 261 } 262 Value *EmitXor(const BinOpInfo &Ops) { 263 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 264 } 265 Value *EmitOr (const BinOpInfo &Ops) { 266 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 267 } 268 269 BinOpInfo EmitBinOps(const BinaryOperator *E); 270 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 271 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 272 273 // Binary operators and binary compound assignment operators. 274#define HANDLEBINOP(OP) \ 275 Value *VisitBin ## OP(const BinaryOperator *E) { \ 276 return Emit ## OP(EmitBinOps(E)); \ 277 } \ 278 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 279 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 280 } 281 HANDLEBINOP(Mul); 282 HANDLEBINOP(Div); 283 HANDLEBINOP(Rem); 284 HANDLEBINOP(Add); 285 HANDLEBINOP(Sub); 286 HANDLEBINOP(Shl); 287 HANDLEBINOP(Shr); 288 HANDLEBINOP(And); 289 HANDLEBINOP(Xor); 290 HANDLEBINOP(Or); 291#undef HANDLEBINOP 292 293 // Comparisons. 294 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 295 unsigned SICmpOpc, unsigned FCmpOpc); 296#define VISITCOMP(CODE, UI, SI, FP) \ 297 Value *VisitBin##CODE(const BinaryOperator *E) { \ 298 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 299 llvm::FCmpInst::FP); } 300 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT); 301 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT); 302 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE); 303 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE); 304 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ); 305 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE); 306#undef VISITCOMP 307 308 Value *VisitBinAssign (const BinaryOperator *E); 309 310 Value *VisitBinLAnd (const BinaryOperator *E); 311 Value *VisitBinLOr (const BinaryOperator *E); 312 Value *VisitBinComma (const BinaryOperator *E); 313 314 // Other Operators. 315 Value *VisitConditionalOperator(const ConditionalOperator *CO); 316 Value *VisitChooseExpr(ChooseExpr *CE); 317 Value *VisitOverloadExpr(OverloadExpr *OE); 318 Value *VisitVAArgExpr(VAArgExpr *VE); 319 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 320 return CGF.EmitObjCStringLiteral(E); 321 } 322 Value *VisitObjCEncodeExpr(const ObjCEncodeExpr *E); 323}; 324} // end anonymous namespace. 325 326//===----------------------------------------------------------------------===// 327// Utilities 328//===----------------------------------------------------------------------===// 329 330/// EmitConversionToBool - Convert the specified expression value to a 331/// boolean (i1) truth value. This is equivalent to "Val != 0". 332Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 333 assert(SrcType->isCanonical() && "EmitScalarConversion strips typedefs"); 334 335 if (SrcType->isRealFloatingType()) { 336 // Compare against 0.0 for fp scalars. 337 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 338 return Builder.CreateFCmpUNE(Src, Zero, "tobool"); 339 } 340 341 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 342 "Unknown scalar type to convert"); 343 344 // Because of the type rules of C, we often end up computing a logical value, 345 // then zero extending it to int, then wanting it as a logical value again. 346 // Optimize this common case. 347 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) { 348 if (ZI->getOperand(0)->getType() == llvm::Type::Int1Ty) { 349 Value *Result = ZI->getOperand(0); 350 // If there aren't any more uses, zap the instruction to save space. 351 // Note that there can be more uses, for example if this 352 // is the result of an assignment. 353 if (ZI->use_empty()) 354 ZI->eraseFromParent(); 355 return Result; 356 } 357 } 358 359 // Compare against an integer or pointer null. 360 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 361 return Builder.CreateICmpNE(Src, Zero, "tobool"); 362} 363 364/// EmitScalarConversion - Emit a conversion from the specified type to the 365/// specified destination type, both of which are LLVM scalar types. 366Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 367 QualType DstType) { 368 SrcType = CGF.getContext().getCanonicalType(SrcType); 369 DstType = CGF.getContext().getCanonicalType(DstType); 370 if (SrcType == DstType) return Src; 371 372 if (DstType->isVoidType()) return 0; 373 374 // Handle conversions to bool first, they are special: comparisons against 0. 375 if (DstType->isBooleanType()) 376 return EmitConversionToBool(Src, SrcType); 377 378 const llvm::Type *DstTy = ConvertType(DstType); 379 380 // Ignore conversions like int -> uint. 381 if (Src->getType() == DstTy) 382 return Src; 383 384 // Handle pointer conversions next: pointers can only be converted 385 // to/from other pointers and integers. Check for pointer types in 386 // terms of LLVM, as some native types (like Obj-C id) may map to a 387 // pointer type. 388 if (isa<llvm::PointerType>(DstTy)) { 389 // The source value may be an integer, or a pointer. 390 if (isa<llvm::PointerType>(Src->getType())) 391 return Builder.CreateBitCast(Src, DstTy, "conv"); 392 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 393 return Builder.CreateIntToPtr(Src, DstTy, "conv"); 394 } 395 396 if (isa<llvm::PointerType>(Src->getType())) { 397 // Must be an ptr to int cast. 398 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 399 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 400 } 401 402 // A scalar can be splatted to an extended vector of the same element type 403 if (DstType->isExtVectorType() && !isa<VectorType>(SrcType) && 404 cast<llvm::VectorType>(DstTy)->getElementType() == Src->getType()) 405 return CGF.EmitVector(&Src, DstType->getAsVectorType()->getNumElements(), 406 true); 407 408 // Allow bitcast from vector to integer/fp of the same size. 409 if (isa<llvm::VectorType>(Src->getType()) || 410 isa<llvm::VectorType>(DstTy)) 411 return Builder.CreateBitCast(Src, DstTy, "conv"); 412 413 // Finally, we have the arithmetic types: real int/float. 414 if (isa<llvm::IntegerType>(Src->getType())) { 415 bool InputSigned = SrcType->isSignedIntegerType(); 416 if (isa<llvm::IntegerType>(DstTy)) 417 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 418 else if (InputSigned) 419 return Builder.CreateSIToFP(Src, DstTy, "conv"); 420 else 421 return Builder.CreateUIToFP(Src, DstTy, "conv"); 422 } 423 424 assert(Src->getType()->isFloatingPoint() && "Unknown real conversion"); 425 if (isa<llvm::IntegerType>(DstTy)) { 426 if (DstType->isSignedIntegerType()) 427 return Builder.CreateFPToSI(Src, DstTy, "conv"); 428 else 429 return Builder.CreateFPToUI(Src, DstTy, "conv"); 430 } 431 432 assert(DstTy->isFloatingPoint() && "Unknown real conversion"); 433 if (DstTy->getTypeID() < Src->getType()->getTypeID()) 434 return Builder.CreateFPTrunc(Src, DstTy, "conv"); 435 else 436 return Builder.CreateFPExt(Src, DstTy, "conv"); 437} 438 439/// EmitComplexToScalarConversion - Emit a conversion from the specified 440/// complex type to the specified destination type, where the destination 441/// type is an LLVM scalar type. 442Value *ScalarExprEmitter:: 443EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 444 QualType SrcTy, QualType DstTy) { 445 // Get the source element type. 446 SrcTy = SrcTy->getAsComplexType()->getElementType(); 447 448 // Handle conversions to bool first, they are special: comparisons against 0. 449 if (DstTy->isBooleanType()) { 450 // Complex != 0 -> (Real != 0) | (Imag != 0) 451 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 452 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 453 return Builder.CreateOr(Src.first, Src.second, "tobool"); 454 } 455 456 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 457 // the imaginary part of the complex value is discarded and the value of the 458 // real part is converted according to the conversion rules for the 459 // corresponding real type. 460 return EmitScalarConversion(Src.first, SrcTy, DstTy); 461} 462 463 464//===----------------------------------------------------------------------===// 465// Visitor Methods 466//===----------------------------------------------------------------------===// 467 468Value *ScalarExprEmitter::VisitExpr(Expr *E) { 469 CGF.ErrorUnsupported(E, "scalar expression"); 470 if (E->getType()->isVoidType()) 471 return 0; 472 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 473} 474 475Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 476 llvm::SmallVector<llvm::Constant*, 32> indices; 477 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 478 indices.push_back(cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i)))); 479 } 480 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 481 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 482 Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); 483 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 484} 485 486Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 487 // Emit subscript expressions in rvalue context's. For most cases, this just 488 // loads the lvalue formed by the subscript expr. However, we have to be 489 // careful, because the base of a vector subscript is occasionally an rvalue, 490 // so we can't get it as an lvalue. 491 if (!E->getBase()->getType()->isVectorType()) 492 return EmitLoadOfLValue(E); 493 494 // Handle the vector case. The base must be a vector, the index must be an 495 // integer value. 496 Value *Base = Visit(E->getBase()); 497 Value *Idx = Visit(E->getIdx()); 498 499 // FIXME: Convert Idx to i32 type. 500 return Builder.CreateExtractElement(Base, Idx, "vecext"); 501} 502 503/// VisitImplicitCastExpr - Implicit casts are the same as normal casts, but 504/// also handle things like function to pointer-to-function decay, and array to 505/// pointer decay. 506Value *ScalarExprEmitter::VisitImplicitCastExpr(const ImplicitCastExpr *E) { 507 const Expr *Op = E->getSubExpr(); 508 509 // If this is due to array->pointer conversion, emit the array expression as 510 // an l-value. 511 if (Op->getType()->isArrayType()) { 512 // FIXME: For now we assume that all source arrays map to LLVM arrays. This 513 // will not true when we add support for VLAs. 514 Value *V = EmitLValue(Op).getAddress(); // Bitfields can't be arrays. 515 516 if (!(isa<llvm::PointerType>(V->getType()) && 517 isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 518 ->getElementType()))) { 519 CGF.ErrorUnsupported(E, "variable-length array cast"); 520 if (E->getType()->isVoidType()) 521 return 0; 522 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 523 } 524 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 525 526 // The resultant pointer type can be implicitly casted to other pointer 527 // types as well (e.g. void*) and can be implicitly converted to integer. 528 const llvm::Type *DestTy = ConvertType(E->getType()); 529 if (V->getType() != DestTy) { 530 if (isa<llvm::PointerType>(DestTy)) 531 V = Builder.CreateBitCast(V, DestTy, "ptrconv"); 532 else { 533 assert(isa<llvm::IntegerType>(DestTy) && "Unknown array decay"); 534 V = Builder.CreatePtrToInt(V, DestTy, "ptrconv"); 535 } 536 } 537 return V; 538 539 } else if (E->getType()->isReferenceType()) { 540 return EmitLValue(Op).getAddress(); 541 } 542 543 return EmitCastExpr(Op, E->getType()); 544} 545 546 547// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 548// have to handle a more broad range of conversions than explicit casts, as they 549// handle things like function to ptr-to-function decay etc. 550Value *ScalarExprEmitter::EmitCastExpr(const Expr *E, QualType DestTy) { 551 // Handle cases where the source is an non-complex type. 552 553 if (!CGF.hasAggregateLLVMType(E->getType())) { 554 Value *Src = Visit(const_cast<Expr*>(E)); 555 556 // Use EmitScalarConversion to perform the conversion. 557 return EmitScalarConversion(Src, E->getType(), DestTy); 558 } 559 560 if (E->getType()->isAnyComplexType()) { 561 // Handle cases where the source is a complex type. 562 return EmitComplexToScalarConversion(CGF.EmitComplexExpr(E), E->getType(), 563 DestTy); 564 } 565 566 // Okay, this is a cast from an aggregate. It must be a cast to void. Just 567 // evaluate the result and return. 568 CGF.EmitAggExpr(E, 0, false); 569 return 0; 570} 571 572Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 573 return CGF.EmitCompoundStmt(*E->getSubStmt(), 574 !E->getType()->isVoidType()).getScalarVal(); 575} 576 577 578//===----------------------------------------------------------------------===// 579// Unary Operators 580//===----------------------------------------------------------------------===// 581 582Value *ScalarExprEmitter::VisitPrePostIncDec(const UnaryOperator *E, 583 bool isInc, bool isPre) { 584 LValue LV = EmitLValue(E->getSubExpr()); 585 // FIXME: Handle volatile! 586 Value *InVal = CGF.EmitLoadOfLValue(LV, // false 587 E->getSubExpr()->getType()).getScalarVal(); 588 589 int AmountVal = isInc ? 1 : -1; 590 591 Value *NextVal; 592 if (isa<llvm::PointerType>(InVal->getType())) { 593 // FIXME: This isn't right for VLAs. 594 NextVal = llvm::ConstantInt::get(llvm::Type::Int32Ty, AmountVal); 595 NextVal = Builder.CreateGEP(InVal, NextVal, "ptrincdec"); 596 } else { 597 // Add the inc/dec to the real part. 598 if (isa<llvm::IntegerType>(InVal->getType())) 599 NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); 600 else if (InVal->getType() == llvm::Type::FloatTy) 601 NextVal = 602 llvm::ConstantFP::get(llvm::APFloat(static_cast<float>(AmountVal))); 603 else if (InVal->getType() == llvm::Type::DoubleTy) 604 NextVal = 605 llvm::ConstantFP::get(llvm::APFloat(static_cast<double>(AmountVal))); 606 else { 607 llvm::APFloat F(static_cast<float>(AmountVal)); 608 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero); 609 NextVal = llvm::ConstantFP::get(F); 610 } 611 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 612 } 613 614 // Store the updated result through the lvalue. 615 CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV, 616 E->getSubExpr()->getType()); 617 618 // If this is a postinc, return the value read from memory, otherwise use the 619 // updated value. 620 return isPre ? NextVal : InVal; 621} 622 623 624Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 625 Value *Op = Visit(E->getSubExpr()); 626 return Builder.CreateNeg(Op, "neg"); 627} 628 629Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 630 Value *Op = Visit(E->getSubExpr()); 631 return Builder.CreateNot(Op, "neg"); 632} 633 634Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 635 // Compare operand to zero. 636 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 637 638 // Invert value. 639 // TODO: Could dynamically modify easy computations here. For example, if 640 // the operand is an icmp ne, turn into icmp eq. 641 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 642 643 // ZExt result to int. 644 return Builder.CreateZExt(BoolVal, CGF.LLVMIntTy, "lnot.ext"); 645} 646 647/// EmitSizeAlignOf - Return the size or alignment of the 'TypeToSize' type as 648/// an integer (RetType). 649Value *ScalarExprEmitter::EmitSizeAlignOf(QualType TypeToSize, 650 QualType RetType,bool isSizeOf){ 651 assert(RetType->isIntegerType() && "Result type must be an integer!"); 652 uint32_t ResultWidth = 653 static_cast<uint32_t>(CGF.getContext().getTypeSize(RetType)); 654 655 // sizeof(void) and __alignof__(void) = 1 as a gcc extension. Also 656 // for function types. 657 // FIXME: what is alignof a function type in gcc? 658 if (TypeToSize->isVoidType() || TypeToSize->isFunctionType()) 659 return llvm::ConstantInt::get(llvm::APInt(ResultWidth, 1)); 660 661 /// FIXME: This doesn't handle VLAs yet! 662 std::pair<uint64_t, unsigned> Info = CGF.getContext().getTypeInfo(TypeToSize); 663 664 uint64_t Val = isSizeOf ? Info.first : Info.second; 665 Val /= 8; // Return size in bytes, not bits. 666 667 return llvm::ConstantInt::get(llvm::APInt(ResultWidth, Val)); 668} 669 670Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 671 Expr *Op = E->getSubExpr(); 672 if (Op->getType()->isAnyComplexType()) 673 return CGF.EmitComplexExpr(Op).first; 674 return Visit(Op); 675} 676Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 677 Expr *Op = E->getSubExpr(); 678 if (Op->getType()->isAnyComplexType()) 679 return CGF.EmitComplexExpr(Op).second; 680 681 // __imag on a scalar returns zero. Emit it the subexpr to ensure side 682 // effects are evaluated. 683 CGF.EmitScalarExpr(Op); 684 return llvm::Constant::getNullValue(ConvertType(E->getType())); 685} 686 687Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) 688{ 689 int64_t Val = E->evaluateOffsetOf(CGF.getContext()); 690 691 assert(E->getType()->isIntegerType() && "Result type must be an integer!"); 692 693 uint32_t ResultWidth = 694 static_cast<uint32_t>(CGF.getContext().getTypeSize(E->getType())); 695 return llvm::ConstantInt::get(llvm::APInt(ResultWidth, Val)); 696} 697 698//===----------------------------------------------------------------------===// 699// Binary Operators 700//===----------------------------------------------------------------------===// 701 702BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 703 BinOpInfo Result; 704 Result.LHS = Visit(E->getLHS()); 705 Result.RHS = Visit(E->getRHS()); 706 Result.Ty = E->getType(); 707 Result.E = E; 708 return Result; 709} 710 711Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 712 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 713 QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType(); 714 715 BinOpInfo OpInfo; 716 717 // Load the LHS and RHS operands. 718 LValue LHSLV = EmitLValue(E->getLHS()); 719 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 720 721 // Determine the computation type. If the RHS is complex, then this is one of 722 // the add/sub/mul/div operators. All of these operators can be computed in 723 // with just their real component even though the computation domain really is 724 // complex. 725 QualType ComputeType = E->getComputationType(); 726 727 // If the computation type is complex, then the RHS is complex. Emit the RHS. 728 if (const ComplexType *CT = ComputeType->getAsComplexType()) { 729 ComputeType = CT->getElementType(); 730 731 // Emit the RHS, only keeping the real component. 732 OpInfo.RHS = CGF.EmitComplexExpr(E->getRHS()).first; 733 RHSTy = RHSTy->getAsComplexType()->getElementType(); 734 } else { 735 // Otherwise the RHS is a simple scalar value. 736 OpInfo.RHS = Visit(E->getRHS()); 737 } 738 739 QualType LComputeTy, RComputeTy, ResultTy; 740 741 // Compound assignment does not contain enough information about all 742 // the types involved for pointer arithmetic cases. Figure it out 743 // here for now. 744 if (E->getLHS()->getType()->isPointerType()) { 745 // Pointer arithmetic cases: ptr +=,-= int and ptr -= ptr, 746 assert((E->getOpcode() == BinaryOperator::AddAssign || 747 E->getOpcode() == BinaryOperator::SubAssign) && 748 "Invalid compound assignment operator on pointer type."); 749 LComputeTy = E->getLHS()->getType(); 750 751 if (E->getRHS()->getType()->isPointerType()) { 752 // Degenerate case of (ptr -= ptr) allowed by GCC implicit cast 753 // extension, the conversion from the pointer difference back to 754 // the LHS type is handled at the end. 755 assert(E->getOpcode() == BinaryOperator::SubAssign && 756 "Invalid compound assignment operator on pointer type."); 757 RComputeTy = E->getLHS()->getType(); 758 ResultTy = CGF.getContext().getPointerDiffType(); 759 } else { 760 RComputeTy = E->getRHS()->getType(); 761 ResultTy = LComputeTy; 762 } 763 } else if (E->getRHS()->getType()->isPointerType()) { 764 // Degenerate case of (int += ptr) allowed by GCC implicit cast 765 // extension. 766 assert(E->getOpcode() == BinaryOperator::AddAssign && 767 "Invalid compound assignment operator on pointer type."); 768 LComputeTy = E->getLHS()->getType(); 769 RComputeTy = E->getRHS()->getType(); 770 ResultTy = RComputeTy; 771 } else { 772 LComputeTy = RComputeTy = ResultTy = ComputeType; 773 } 774 775 // Convert the LHS/RHS values to the computation type. 776 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, LComputeTy); 777 OpInfo.RHS = EmitScalarConversion(OpInfo.RHS, RHSTy, RComputeTy); 778 OpInfo.Ty = ResultTy; 779 OpInfo.E = E; 780 781 // Expand the binary operator. 782 Value *Result = (this->*Func)(OpInfo); 783 784 // Convert the result back to the LHS type. 785 Result = EmitScalarConversion(Result, ResultTy, LHSTy); 786 787 // Store the result value into the LHS lvalue. 788 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); 789 790 // For bitfields, we need the value in the bitfield. Note that 791 // property references do not reload their value (even though the 792 // setter may have changed it). 793 // FIXME: This adds an extra bitfield load 794 if (LHSLV.isBitfield()) 795 Result = EmitLoadOfLValue(LHSLV, LHSTy); 796 return Result; 797} 798 799 800Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 801 if (Ops.LHS->getType()->isFPOrFPVector()) 802 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 803 else if (Ops.Ty->isUnsignedIntegerType()) 804 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 805 else 806 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 807} 808 809Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 810 // Rem in C can't be a floating point type: C99 6.5.5p2. 811 if (Ops.Ty->isUnsignedIntegerType()) 812 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 813 else 814 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 815} 816 817 818Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 819 if (!Ops.Ty->isPointerType()) 820 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 821 822 // FIXME: What about a pointer to a VLA? 823 Value *Ptr, *Idx; 824 Expr *IdxExp; 825 if (isa<llvm::PointerType>(Ops.LHS->getType())) { // pointer + int 826 Ptr = Ops.LHS; 827 Idx = Ops.RHS; 828 IdxExp = Ops.E->getRHS(); 829 } else { // int + pointer 830 Ptr = Ops.RHS; 831 Idx = Ops.LHS; 832 IdxExp = Ops.E->getLHS(); 833 } 834 835 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 836 if (Width < CGF.LLVMPointerWidth) { 837 // Zero or sign extend the pointer value based on whether the index is 838 // signed or not. 839 const llvm::Type *IdxType = llvm::IntegerType::get(CGF.LLVMPointerWidth); 840 if (IdxExp->getType()->isSignedIntegerType()) 841 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 842 else 843 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 844 } 845 846 return Builder.CreateGEP(Ptr, Idx, "add.ptr"); 847} 848 849Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 850 if (!isa<llvm::PointerType>(Ops.LHS->getType())) 851 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 852 853 if (!isa<llvm::PointerType>(Ops.RHS->getType())) { 854 // pointer - int 855 Value *Idx = Ops.RHS; 856 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 857 if (Width < CGF.LLVMPointerWidth) { 858 // Zero or sign extend the pointer value based on whether the index is 859 // signed or not. 860 const llvm::Type *IdxType = llvm::IntegerType::get(CGF.LLVMPointerWidth); 861 if (Ops.E->getRHS()->getType()->isSignedIntegerType()) 862 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 863 else 864 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 865 } 866 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); 867 868 // FIXME: The pointer could point to a VLA. 869 // The GNU void* - int case is automatically handled here because 870 // our LLVM type for void* is i8*. 871 return Builder.CreateGEP(Ops.LHS, Idx, "sub.ptr"); 872 } else { 873 // pointer - pointer 874 Value *LHS = Ops.LHS; 875 Value *RHS = Ops.RHS; 876 877 const QualType LHSType = Ops.E->getLHS()->getType(); 878 const QualType LHSElementType = LHSType->getAsPointerType()->getPointeeType(); 879 uint64_t ElementSize; 880 881 // Handle GCC extension for pointer arithmetic on void* types. 882 if (LHSElementType->isVoidType()) { 883 ElementSize = 1; 884 } else { 885 ElementSize = CGF.getContext().getTypeSize(LHSElementType) / 8; 886 } 887 888 const llvm::Type *ResultType = ConvertType(Ops.Ty); 889 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 890 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 891 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 892 893 // HACK: LLVM doesn't have an divide instruction that 'knows' there is no 894 // remainder. As such, we handle common power-of-two cases here to generate 895 // better code. See PR2247. 896 if (llvm::isPowerOf2_64(ElementSize)) { 897 Value *ShAmt = 898 llvm::ConstantInt::get(ResultType, llvm::Log2_64(ElementSize)); 899 return Builder.CreateAShr(BytesBetween, ShAmt, "sub.ptr.shr"); 900 } 901 902 // Otherwise, do a full sdiv. 903 Value *BytesPerElt = llvm::ConstantInt::get(ResultType, ElementSize); 904 return Builder.CreateSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 905 } 906} 907 908Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 909 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 910 // RHS to the same size as the LHS. 911 Value *RHS = Ops.RHS; 912 if (Ops.LHS->getType() != RHS->getType()) 913 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 914 915 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 916} 917 918Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 919 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 920 // RHS to the same size as the LHS. 921 Value *RHS = Ops.RHS; 922 if (Ops.LHS->getType() != RHS->getType()) 923 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 924 925 if (Ops.Ty->isUnsignedIntegerType()) 926 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 927 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 928} 929 930Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 931 unsigned SICmpOpc, unsigned FCmpOpc) { 932 Value *Result; 933 QualType LHSTy = E->getLHS()->getType(); 934 if (!LHSTy->isAnyComplexType() && !LHSTy->isVectorType()) { 935 Value *LHS = Visit(E->getLHS()); 936 Value *RHS = Visit(E->getRHS()); 937 938 if (LHS->getType()->isFloatingPoint()) { 939 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 940 LHS, RHS, "cmp"); 941 } else if (LHSTy->isSignedIntegerType()) { 942 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 943 LHS, RHS, "cmp"); 944 } else { 945 // Unsigned integers and pointers. 946 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 947 LHS, RHS, "cmp"); 948 } 949 } else if (LHSTy->isVectorType()) { 950 Value *LHS = Visit(E->getLHS()); 951 Value *RHS = Visit(E->getRHS()); 952 953 if (LHS->getType()->isFPOrFPVector()) { 954 Result = Builder.CreateVFCmp((llvm::CmpInst::Predicate)FCmpOpc, 955 LHS, RHS, "cmp"); 956 } else if (LHSTy->isUnsignedIntegerType()) { 957 Result = Builder.CreateVICmp((llvm::CmpInst::Predicate)UICmpOpc, 958 LHS, RHS, "cmp"); 959 } else { 960 // Signed integers and pointers. 961 Result = Builder.CreateVICmp((llvm::CmpInst::Predicate)SICmpOpc, 962 LHS, RHS, "cmp"); 963 } 964 return Result; 965 } else { 966 // Complex Comparison: can only be an equality comparison. 967 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 968 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 969 970 QualType CETy = LHSTy->getAsComplexType()->getElementType(); 971 972 Value *ResultR, *ResultI; 973 if (CETy->isRealFloatingType()) { 974 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 975 LHS.first, RHS.first, "cmp.r"); 976 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 977 LHS.second, RHS.second, "cmp.i"); 978 } else { 979 // Complex comparisons can only be equality comparisons. As such, signed 980 // and unsigned opcodes are the same. 981 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 982 LHS.first, RHS.first, "cmp.r"); 983 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 984 LHS.second, RHS.second, "cmp.i"); 985 } 986 987 if (E->getOpcode() == BinaryOperator::EQ) { 988 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 989 } else { 990 assert(E->getOpcode() == BinaryOperator::NE && 991 "Complex comparison other than == or != ?"); 992 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 993 } 994 } 995 996 // ZExt result to int. 997 return Builder.CreateZExt(Result, CGF.LLVMIntTy, "cmp.ext"); 998} 999 1000Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 1001 LValue LHS = EmitLValue(E->getLHS()); 1002 Value *RHS = Visit(E->getRHS()); 1003 1004 // Store the value into the LHS. 1005 // FIXME: Volatility! 1006 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 1007 1008 // For bitfields, we need the value in the bitfield. Note that 1009 // property references do not reload their value (even though the 1010 // setter may have changed it). 1011 // FIXME: This adds an extra bitfield load 1012 if (LHS.isBitfield()) 1013 return EmitLoadOfLValue(LHS, E->getLHS()->getType()); 1014 1015 // Return the RHS. 1016 return RHS; 1017} 1018 1019Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 1020 Value *LHSCond = CGF.EvaluateExprAsBool(E->getLHS()); 1021 1022 llvm::BasicBlock *ContBlock = llvm::BasicBlock::Create("land_cont"); 1023 llvm::BasicBlock *RHSBlock = llvm::BasicBlock::Create("land_rhs"); 1024 1025 llvm::BasicBlock *OrigBlock = Builder.GetInsertBlock(); 1026 Builder.CreateCondBr(LHSCond, RHSBlock, ContBlock); 1027 1028 CGF.EmitBlock(RHSBlock); 1029 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1030 1031 // Reaquire the RHS block, as there may be subblocks inserted. 1032 RHSBlock = Builder.GetInsertBlock(); 1033 CGF.EmitBlock(ContBlock); 1034 1035 // Create a PHI node. If we just evaluted the LHS condition, the result is 1036 // false. If we evaluated both, the result is the RHS condition. 1037 llvm::PHINode *PN = Builder.CreatePHI(llvm::Type::Int1Ty, "land"); 1038 PN->reserveOperandSpace(2); 1039 PN->addIncoming(llvm::ConstantInt::getFalse(), OrigBlock); 1040 PN->addIncoming(RHSCond, RHSBlock); 1041 1042 // ZExt result to int. 1043 return Builder.CreateZExt(PN, CGF.LLVMIntTy, "land.ext"); 1044} 1045 1046Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 1047 Value *LHSCond = CGF.EvaluateExprAsBool(E->getLHS()); 1048 1049 llvm::BasicBlock *ContBlock = llvm::BasicBlock::Create("lor_cont"); 1050 llvm::BasicBlock *RHSBlock = llvm::BasicBlock::Create("lor_rhs"); 1051 1052 llvm::BasicBlock *OrigBlock = Builder.GetInsertBlock(); 1053 Builder.CreateCondBr(LHSCond, ContBlock, RHSBlock); 1054 1055 CGF.EmitBlock(RHSBlock); 1056 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1057 1058 // Reaquire the RHS block, as there may be subblocks inserted. 1059 RHSBlock = Builder.GetInsertBlock(); 1060 CGF.EmitBlock(ContBlock); 1061 1062 // Create a PHI node. If we just evaluted the LHS condition, the result is 1063 // true. If we evaluated both, the result is the RHS condition. 1064 llvm::PHINode *PN = Builder.CreatePHI(llvm::Type::Int1Ty, "lor"); 1065 PN->reserveOperandSpace(2); 1066 PN->addIncoming(llvm::ConstantInt::getTrue(), OrigBlock); 1067 PN->addIncoming(RHSCond, RHSBlock); 1068 1069 // ZExt result to int. 1070 return Builder.CreateZExt(PN, CGF.LLVMIntTy, "lor.ext"); 1071} 1072 1073Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 1074 CGF.EmitStmt(E->getLHS()); 1075 return Visit(E->getRHS()); 1076} 1077 1078//===----------------------------------------------------------------------===// 1079// Other Operators 1080//===----------------------------------------------------------------------===// 1081 1082Value *ScalarExprEmitter:: 1083VisitConditionalOperator(const ConditionalOperator *E) { 1084 llvm::BasicBlock *LHSBlock = llvm::BasicBlock::Create("cond.?"); 1085 llvm::BasicBlock *RHSBlock = llvm::BasicBlock::Create("cond.:"); 1086 llvm::BasicBlock *ContBlock = llvm::BasicBlock::Create("cond.cont"); 1087 1088 // Evaluate the conditional, then convert it to bool. We do this explicitly 1089 // because we need the unconverted value if this is a GNU ?: expression with 1090 // missing middle value. 1091 Value *CondVal = CGF.EmitScalarExpr(E->getCond()); 1092 Value *CondBoolVal =CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 1093 CGF.getContext().BoolTy); 1094 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 1095 1096 CGF.EmitBlock(LHSBlock); 1097 1098 // Handle the GNU extension for missing LHS. 1099 Value *LHS; 1100 if (E->getLHS()) 1101 LHS = Visit(E->getLHS()); 1102 else // Perform promotions, to handle cases like "short ?: int" 1103 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); 1104 1105 Builder.CreateBr(ContBlock); 1106 LHSBlock = Builder.GetInsertBlock(); 1107 1108 CGF.EmitBlock(RHSBlock); 1109 1110 Value *RHS = Visit(E->getRHS()); 1111 Builder.CreateBr(ContBlock); 1112 RHSBlock = Builder.GetInsertBlock(); 1113 1114 CGF.EmitBlock(ContBlock); 1115 1116 if (!LHS || !RHS) { 1117 assert(E->getType()->isVoidType() && "Non-void value should have a value"); 1118 return 0; 1119 } 1120 1121 // Create a PHI node for the real part. 1122 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 1123 PN->reserveOperandSpace(2); 1124 PN->addIncoming(LHS, LHSBlock); 1125 PN->addIncoming(RHS, RHSBlock); 1126 return PN; 1127} 1128 1129Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 1130 // Emit the LHS or RHS as appropriate. 1131 return 1132 Visit(E->isConditionTrue(CGF.getContext()) ? E->getLHS() : E->getRHS()); 1133} 1134 1135Value *ScalarExprEmitter::VisitOverloadExpr(OverloadExpr *E) { 1136 return CGF.EmitCallExpr(E->getFn(), E->arg_begin(), 1137 E->arg_end(CGF.getContext())).getScalarVal(); 1138} 1139 1140Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 1141 llvm::Value *ArgValue = EmitLValue(VE->getSubExpr()).getAddress(); 1142 1143 llvm::Value *V = Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 1144 return V; 1145} 1146 1147Value *ScalarExprEmitter::VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { 1148 std::string str; 1149 llvm::SmallVector<const RecordType *, 8> EncodingRecordTypes; 1150 CGF.getContext().getObjCEncodingForType(E->getEncodedType(), str, 1151 EncodingRecordTypes); 1152 1153 llvm::Constant *C = llvm::ConstantArray::get(str); 1154 C = new llvm::GlobalVariable(C->getType(), true, 1155 llvm::GlobalValue::InternalLinkage, 1156 C, ".str", &CGF.CGM.getModule()); 1157 llvm::Constant *Zero = llvm::Constant::getNullValue(llvm::Type::Int32Ty); 1158 llvm::Constant *Zeros[] = { Zero, Zero }; 1159 C = llvm::ConstantExpr::getGetElementPtr(C, Zeros, 2); 1160 1161 return C; 1162} 1163 1164//===----------------------------------------------------------------------===// 1165// Entry Point into this File 1166//===----------------------------------------------------------------------===// 1167 1168/// EmitComplexExpr - Emit the computation of the specified expression of 1169/// complex type, ignoring the result. 1170Value *CodeGenFunction::EmitScalarExpr(const Expr *E) { 1171 assert(E && !hasAggregateLLVMType(E->getType()) && 1172 "Invalid scalar expression to emit"); 1173 1174 return ScalarExprEmitter(*this).Visit(const_cast<Expr*>(E)); 1175} 1176 1177/// EmitScalarConversion - Emit a conversion from the specified type to the 1178/// specified destination type, both of which are LLVM scalar types. 1179Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 1180 QualType DstTy) { 1181 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 1182 "Invalid scalar expression to emit"); 1183 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 1184} 1185 1186/// EmitComplexToScalarConversion - Emit a conversion from the specified 1187/// complex type to the specified destination type, where the destination 1188/// type is an LLVM scalar type. 1189Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 1190 QualType SrcTy, 1191 QualType DstTy) { 1192 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 1193 "Invalid complex -> scalar conversion"); 1194 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 1195 DstTy); 1196} 1197 1198Value *CodeGenFunction::EmitShuffleVector(Value* V1, Value *V2, ...) { 1199 assert(V1->getType() == V2->getType() && 1200 "Vector operands must be of the same type"); 1201 unsigned NumElements = 1202 cast<llvm::VectorType>(V1->getType())->getNumElements(); 1203 1204 va_list va; 1205 va_start(va, V2); 1206 1207 llvm::SmallVector<llvm::Constant*, 16> Args; 1208 for (unsigned i = 0; i < NumElements; i++) { 1209 int n = va_arg(va, int); 1210 assert(n >= 0 && n < (int)NumElements * 2 && 1211 "Vector shuffle index out of bounds!"); 1212 Args.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, n)); 1213 } 1214 1215 const char *Name = va_arg(va, const char *); 1216 va_end(va); 1217 1218 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 1219 1220 return Builder.CreateShuffleVector(V1, V2, Mask, Name); 1221} 1222 1223llvm::Value *CodeGenFunction::EmitVector(llvm::Value * const *Vals, 1224 unsigned NumVals, bool isSplat) { 1225 llvm::Value *Vec 1226 = llvm::UndefValue::get(llvm::VectorType::get(Vals[0]->getType(), NumVals)); 1227 1228 for (unsigned i = 0, e = NumVals; i != e; ++i) { 1229 llvm::Value *Val = isSplat ? Vals[0] : Vals[i]; 1230 llvm::Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); 1231 Vec = Builder.CreateInsertElement(Vec, Val, Idx, "tmp"); 1232 } 1233 1234 return Vec; 1235} 1236