CGExprScalar.cpp revision 5549976193e34417d4474a5f4a514268ef6666c7
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/AST.h" 17#include "clang/Basic/TargetInfo.h" 18#include "llvm/Constants.h" 19#include "llvm/Function.h" 20#include "llvm/GlobalVariable.h" 21#include "llvm/Intrinsics.h" 22#include "llvm/Support/Compiler.h" 23#include <cstdarg> 24 25using namespace clang; 26using namespace CodeGen; 27using llvm::Value; 28 29//===----------------------------------------------------------------------===// 30// Scalar Expression Emitter 31//===----------------------------------------------------------------------===// 32 33struct BinOpInfo { 34 Value *LHS; 35 Value *RHS; 36 QualType Ty; // Computation Type. 37 const BinaryOperator *E; 38}; 39 40namespace { 41class VISIBILITY_HIDDEN ScalarExprEmitter 42 : public StmtVisitor<ScalarExprEmitter, Value*> { 43 CodeGenFunction &CGF; 44 llvm::IRBuilder &Builder; 45 CGObjCRuntime *Runtime; 46 47public: 48 49 ScalarExprEmitter(CodeGenFunction &cgf) : CGF(cgf), 50 Builder(CGF.Builder), 51 Runtime(CGF.CGM.getObjCRuntime()) { 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 *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { 113 return llvm::ConstantInt::get(ConvertType(E->getType()), 114 CGF.getContext().typesAreCompatible( 115 E->getArgType1(), E->getArgType2())); 116 } 117 Value *VisitSizeOfAlignOfTypeExpr(const SizeOfAlignOfTypeExpr *E) { 118 return EmitSizeAlignOf(E->getArgumentType(), E->getType(), E->isSizeOf()); 119 } 120 121 // l-values. 122 Value *VisitDeclRefExpr(DeclRefExpr *E) { 123 if (const EnumConstantDecl *EC = dyn_cast<EnumConstantDecl>(E->getDecl())) 124 return llvm::ConstantInt::get(EC->getInitVal()); 125 return EmitLoadOfLValue(E); 126 } 127 Value *VisitObjCMessageExpr(ObjCMessageExpr *E); 128 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { return EmitLoadOfLValue(E);} 129 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 130 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 131 Value *VisitMemberExpr(Expr *E) { return EmitLoadOfLValue(E); } 132 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 133 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { return EmitLoadOfLValue(E); } 134 Value *VisitStringLiteral(Expr *E) { return EmitLValue(E).getAddress(); } 135 Value *VisitPreDefinedExpr(Expr *E) { return EmitLValue(E).getAddress(); } 136 137 Value *VisitInitListExpr(InitListExpr *E) { 138 unsigned NumInitElements = E->getNumInits(); 139 140 const llvm::VectorType *VType = 141 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 142 143 // We have a scalar in braces. Just use the first element. 144 if (!VType) 145 return Visit(E->getInit(0)); 146 147 unsigned NumVectorElements = VType->getNumElements(); 148 const llvm::Type *ElementType = VType->getElementType(); 149 150 // Emit individual vector element stores. 151 llvm::Value *V = llvm::UndefValue::get(VType); 152 153 // Emit initializers 154 unsigned i; 155 for (i = 0; i < NumInitElements; ++i) { 156 Value *NewV = Visit(E->getInit(i)); 157 Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); 158 V = Builder.CreateInsertElement(V, NewV, Idx); 159 } 160 161 // Emit remaining default initializers 162 for (/* Do not initialize i*/; i < NumVectorElements; ++i) { 163 Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); 164 llvm::Value *NewV = llvm::Constant::getNullValue(ElementType); 165 V = Builder.CreateInsertElement(V, NewV, Idx); 166 } 167 168 return V; 169 } 170 171 Value *VisitImplicitCastExpr(const ImplicitCastExpr *E); 172 Value *VisitCastExpr(const CastExpr *E) { 173 return EmitCastExpr(E->getSubExpr(), E->getType()); 174 } 175 Value *EmitCastExpr(const Expr *E, QualType T); 176 177 Value *VisitCallExpr(const CallExpr *E) { 178 return CGF.EmitCallExpr(E).getScalarVal(); 179 } 180 181 Value *VisitStmtExpr(const StmtExpr *E); 182 183 // Unary Operators. 184 Value *VisitPrePostIncDec(const UnaryOperator *E, bool isInc, bool isPre); 185 Value *VisitUnaryPostDec(const UnaryOperator *E) { 186 return VisitPrePostIncDec(E, false, false); 187 } 188 Value *VisitUnaryPostInc(const UnaryOperator *E) { 189 return VisitPrePostIncDec(E, true, false); 190 } 191 Value *VisitUnaryPreDec(const UnaryOperator *E) { 192 return VisitPrePostIncDec(E, false, true); 193 } 194 Value *VisitUnaryPreInc(const UnaryOperator *E) { 195 return VisitPrePostIncDec(E, true, true); 196 } 197 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 198 return EmitLValue(E->getSubExpr()).getAddress(); 199 } 200 Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } 201 Value *VisitUnaryPlus(const UnaryOperator *E) { 202 return Visit(E->getSubExpr()); 203 } 204 Value *VisitUnaryMinus (const UnaryOperator *E); 205 Value *VisitUnaryNot (const UnaryOperator *E); 206 Value *VisitUnaryLNot (const UnaryOperator *E); 207 Value *VisitUnarySizeOf (const UnaryOperator *E) { 208 return EmitSizeAlignOf(E->getSubExpr()->getType(), E->getType(), true); 209 } 210 Value *VisitUnaryAlignOf (const UnaryOperator *E) { 211 return EmitSizeAlignOf(E->getSubExpr()->getType(), E->getType(), false); 212 } 213 Value *EmitSizeAlignOf(QualType TypeToSize, QualType RetType, 214 bool isSizeOf); 215 Value *VisitUnaryReal (const UnaryOperator *E); 216 Value *VisitUnaryImag (const UnaryOperator *E); 217 Value *VisitUnaryExtension(const UnaryOperator *E) { 218 return Visit(E->getSubExpr()); 219 } 220 Value *VisitUnaryOffsetOf(const UnaryOperator *E); 221 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 222 return Visit(DAE->getExpr()); 223 } 224 225 // Binary Operators. 226 Value *EmitMul(const BinOpInfo &Ops) { 227 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 228 } 229 Value *EmitDiv(const BinOpInfo &Ops); 230 Value *EmitRem(const BinOpInfo &Ops); 231 Value *EmitAdd(const BinOpInfo &Ops); 232 Value *EmitSub(const BinOpInfo &Ops); 233 Value *EmitShl(const BinOpInfo &Ops); 234 Value *EmitShr(const BinOpInfo &Ops); 235 Value *EmitAnd(const BinOpInfo &Ops) { 236 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 237 } 238 Value *EmitXor(const BinOpInfo &Ops) { 239 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 240 } 241 Value *EmitOr (const BinOpInfo &Ops) { 242 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 243 } 244 245 BinOpInfo EmitBinOps(const BinaryOperator *E); 246 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 247 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 248 249 // Binary operators and binary compound assignment operators. 250#define HANDLEBINOP(OP) \ 251 Value *VisitBin ## OP(const BinaryOperator *E) { \ 252 return Emit ## OP(EmitBinOps(E)); \ 253 } \ 254 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 255 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 256 } 257 HANDLEBINOP(Mul); 258 HANDLEBINOP(Div); 259 HANDLEBINOP(Rem); 260 HANDLEBINOP(Add); 261 // (Sub) - Sub is handled specially below for ptr-ptr subtract. 262 HANDLEBINOP(Shl); 263 HANDLEBINOP(Shr); 264 HANDLEBINOP(And); 265 HANDLEBINOP(Xor); 266 HANDLEBINOP(Or); 267#undef HANDLEBINOP 268 Value *VisitBinSub(const BinaryOperator *E); 269 Value *VisitBinSubAssign(const CompoundAssignOperator *E) { 270 return EmitCompoundAssign(E, &ScalarExprEmitter::EmitSub); 271 } 272 273 // Comparisons. 274 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 275 unsigned SICmpOpc, unsigned FCmpOpc); 276#define VISITCOMP(CODE, UI, SI, FP) \ 277 Value *VisitBin##CODE(const BinaryOperator *E) { \ 278 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 279 llvm::FCmpInst::FP); } 280 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT); 281 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT); 282 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE); 283 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE); 284 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ); 285 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE); 286#undef VISITCOMP 287 288 Value *VisitBinAssign (const BinaryOperator *E); 289 290 Value *VisitBinLAnd (const BinaryOperator *E); 291 Value *VisitBinLOr (const BinaryOperator *E); 292 Value *VisitBinComma (const BinaryOperator *E); 293 294 // Other Operators. 295 Value *VisitConditionalOperator(const ConditionalOperator *CO); 296 Value *VisitChooseExpr(ChooseExpr *CE); 297 Value *VisitOverloadExpr(OverloadExpr *OE); 298 Value *VisitVAArgExpr(VAArgExpr *VE); 299 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 300 return CGF.EmitObjCStringLiteral(E); 301 } 302 Value *VisitObjCEncodeExpr(const ObjCEncodeExpr *E); 303}; 304} // end anonymous namespace. 305 306//===----------------------------------------------------------------------===// 307// Utilities 308//===----------------------------------------------------------------------===// 309 310/// EmitConversionToBool - Convert the specified expression value to a 311/// boolean (i1) truth value. This is equivalent to "Val != 0". 312Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 313 assert(SrcType->isCanonical() && "EmitScalarConversion strips typedefs"); 314 315 if (SrcType->isRealFloatingType()) { 316 // Compare against 0.0 for fp scalars. 317 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 318 return Builder.CreateFCmpUNE(Src, Zero, "tobool"); 319 } 320 321 assert((SrcType->isIntegerType() || SrcType->isPointerType()) && 322 "Unknown scalar type to convert"); 323 324 // Because of the type rules of C, we often end up computing a logical value, 325 // then zero extending it to int, then wanting it as a logical value again. 326 // Optimize this common case. 327 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) { 328 if (ZI->getOperand(0)->getType() == llvm::Type::Int1Ty) { 329 Value *Result = ZI->getOperand(0); 330 // If there aren't any more uses, zap the instruction to save space. 331 // Note that there can be more uses, for example if this 332 // is the result of an assignment. 333 if (ZI->use_empty()) 334 ZI->eraseFromParent(); 335 return Result; 336 } 337 } 338 339 // Compare against an integer or pointer null. 340 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 341 return Builder.CreateICmpNE(Src, Zero, "tobool"); 342} 343 344/// EmitScalarConversion - Emit a conversion from the specified type to the 345/// specified destination type, both of which are LLVM scalar types. 346Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 347 QualType DstType) { 348 SrcType = SrcType.getCanonicalType(); 349 DstType = DstType.getCanonicalType(); 350 if (SrcType == DstType) return Src; 351 352 if (DstType->isVoidType()) return 0; 353 354 // Handle conversions to bool first, they are special: comparisons against 0. 355 if (DstType->isBooleanType()) 356 return EmitConversionToBool(Src, SrcType); 357 358 const llvm::Type *DstTy = ConvertType(DstType); 359 360 // Ignore conversions like int -> uint. 361 if (Src->getType() == DstTy) 362 return Src; 363 364 // Handle pointer conversions next: pointers can only be converted to/from 365 // other pointers and integers. 366 if (isa<PointerType>(DstType)) { 367 // The source value may be an integer, or a pointer. 368 if (isa<llvm::PointerType>(Src->getType())) 369 return Builder.CreateBitCast(Src, DstTy, "conv"); 370 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 371 return Builder.CreateIntToPtr(Src, DstTy, "conv"); 372 } 373 374 if (isa<PointerType>(SrcType)) { 375 // Must be an ptr to int cast. 376 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 377 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 378 } 379 380 // A scalar can be splatted to an extended vector of the same element type 381 if (DstType->isExtVectorType() && !isa<VectorType>(SrcType) && 382 cast<llvm::VectorType>(DstTy)->getElementType() == Src->getType()) 383 return CGF.EmitVector(&Src, DstType->getAsVectorType()->getNumElements(), 384 true); 385 386 // Allow bitcast from vector to integer/fp of the same size. 387 if (isa<llvm::VectorType>(Src->getType()) || 388 isa<llvm::VectorType>(DstTy)) 389 return Builder.CreateBitCast(Src, DstTy, "conv"); 390 391 // Finally, we have the arithmetic types: real int/float. 392 if (isa<llvm::IntegerType>(Src->getType())) { 393 bool InputSigned = SrcType->isSignedIntegerType(); 394 if (isa<llvm::IntegerType>(DstTy)) 395 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 396 else if (InputSigned) 397 return Builder.CreateSIToFP(Src, DstTy, "conv"); 398 else 399 return Builder.CreateUIToFP(Src, DstTy, "conv"); 400 } 401 402 assert(Src->getType()->isFloatingPoint() && "Unknown real conversion"); 403 if (isa<llvm::IntegerType>(DstTy)) { 404 if (DstType->isSignedIntegerType()) 405 return Builder.CreateFPToSI(Src, DstTy, "conv"); 406 else 407 return Builder.CreateFPToUI(Src, DstTy, "conv"); 408 } 409 410 assert(DstTy->isFloatingPoint() && "Unknown real conversion"); 411 if (DstTy->getTypeID() < Src->getType()->getTypeID()) 412 return Builder.CreateFPTrunc(Src, DstTy, "conv"); 413 else 414 return Builder.CreateFPExt(Src, DstTy, "conv"); 415} 416 417/// EmitComplexToScalarConversion - Emit a conversion from the specified 418/// complex type to the specified destination type, where the destination 419/// type is an LLVM scalar type. 420Value *ScalarExprEmitter:: 421EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 422 QualType SrcTy, QualType DstTy) { 423 // Get the source element type. 424 SrcTy = cast<ComplexType>(SrcTy.getCanonicalType())->getElementType(); 425 426 // Handle conversions to bool first, they are special: comparisons against 0. 427 if (DstTy->isBooleanType()) { 428 // Complex != 0 -> (Real != 0) | (Imag != 0) 429 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 430 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 431 return Builder.CreateOr(Src.first, Src.second, "tobool"); 432 } 433 434 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 435 // the imaginary part of the complex value is discarded and the value of the 436 // real part is converted according to the conversion rules for the 437 // corresponding real type. 438 return EmitScalarConversion(Src.first, SrcTy, DstTy); 439} 440 441 442//===----------------------------------------------------------------------===// 443// Visitor Methods 444//===----------------------------------------------------------------------===// 445 446Value *ScalarExprEmitter::VisitExpr(Expr *E) { 447 CGF.WarnUnsupported(E, "scalar expression"); 448 if (E->getType()->isVoidType()) 449 return 0; 450 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 451} 452 453Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 454 llvm::SmallVector<llvm::Constant*, 32> indices; 455 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 456 indices.push_back(cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i)))); 457 } 458 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 459 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 460 Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); 461 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 462} 463 464Value *ScalarExprEmitter::VisitObjCMessageExpr(ObjCMessageExpr *E) { 465 // Only the lookup mechanism and first two arguments of the method 466 // implementation vary between runtimes. We can get the receiver and 467 // arguments in generic code. 468 469 // Find the receiver 470 llvm::Value *Receiver = CGF.EmitScalarExpr(E->getReceiver()); 471 472 // Process the arguments 473 unsigned ArgC = E->getNumArgs(); 474 llvm::SmallVector<llvm::Value*, 16> Args; 475 for (unsigned i = 0; i != ArgC; ++i) { 476 Expr *ArgExpr = E->getArg(i); 477 QualType ArgTy = ArgExpr->getType(); 478 if (!CGF.hasAggregateLLVMType(ArgTy)) { 479 // Scalar argument is passed by-value. 480 Args.push_back(CGF.EmitScalarExpr(ArgExpr)); 481 } else if (ArgTy->isAnyComplexType()) { 482 // Make a temporary alloca to pass the argument. 483 llvm::Value *DestMem = CGF.CreateTempAlloca(ConvertType(ArgTy)); 484 CGF.EmitComplexExprIntoAddr(ArgExpr, DestMem, false); 485 Args.push_back(DestMem); 486 } else { 487 llvm::Value *DestMem = CGF.CreateTempAlloca(ConvertType(ArgTy)); 488 CGF.EmitAggExpr(ArgExpr, DestMem, false); 489 Args.push_back(DestMem); 490 } 491 } 492 493 // Get the selector string 494 std::string SelStr = E->getSelector().getName(); 495 llvm::Constant *Selector = CGF.CGM.GetAddrOfConstantString(SelStr); 496 497 llvm::Value *SelPtr = Builder.CreateStructGEP(Selector, 0); 498 return Runtime->GenerateMessageSend(Builder, ConvertType(E->getType()), 499 CGF.LoadObjCSelf(), 500 Receiver, SelPtr, 501 &Args[0], Args.size()); 502} 503 504Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 505 // Emit subscript expressions in rvalue context's. For most cases, this just 506 // loads the lvalue formed by the subscript expr. However, we have to be 507 // careful, because the base of a vector subscript is occasionally an rvalue, 508 // so we can't get it as an lvalue. 509 if (!E->getBase()->getType()->isVectorType()) 510 return EmitLoadOfLValue(E); 511 512 // Handle the vector case. The base must be a vector, the index must be an 513 // integer value. 514 Value *Base = Visit(E->getBase()); 515 Value *Idx = Visit(E->getIdx()); 516 517 // FIXME: Convert Idx to i32 type. 518 return Builder.CreateExtractElement(Base, Idx, "vecext"); 519} 520 521/// VisitImplicitCastExpr - Implicit casts are the same as normal casts, but 522/// also handle things like function to pointer-to-function decay, and array to 523/// pointer decay. 524Value *ScalarExprEmitter::VisitImplicitCastExpr(const ImplicitCastExpr *E) { 525 const Expr *Op = E->getSubExpr(); 526 527 // If this is due to array->pointer conversion, emit the array expression as 528 // an l-value. 529 if (Op->getType()->isArrayType()) { 530 // FIXME: For now we assume that all source arrays map to LLVM arrays. This 531 // will not true when we add support for VLAs. 532 Value *V = EmitLValue(Op).getAddress(); // Bitfields can't be arrays. 533 534 assert(isa<llvm::PointerType>(V->getType()) && 535 isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 536 ->getElementType()) && 537 "Doesn't support VLAs yet!"); 538 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 539 540 // The resultant pointer type can be implicitly casted to other pointer 541 // types as well, for example void*. 542 const llvm::Type *DestPTy = ConvertType(E->getType()); 543 assert(isa<llvm::PointerType>(DestPTy) && 544 "Only expect implicit cast to pointer"); 545 if (V->getType() != DestPTy) 546 V = Builder.CreateBitCast(V, DestPTy, "ptrconv"); 547 return V; 548 549 } else if (E->getType()->isReferenceType()) { 550 assert(cast<ReferenceType>(E->getType().getCanonicalType())-> 551 getPointeeType() == 552 Op->getType().getCanonicalType() && "Incompatible types!"); 553 554 return EmitLValue(Op).getAddress(); 555 } 556 557 return EmitCastExpr(Op, E->getType()); 558} 559 560 561// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 562// have to handle a more broad range of conversions than explicit casts, as they 563// handle things like function to ptr-to-function decay etc. 564Value *ScalarExprEmitter::EmitCastExpr(const Expr *E, QualType DestTy) { 565 // Handle cases where the source is an non-complex type. 566 567 if (!CGF.hasAggregateLLVMType(E->getType())) { 568 Value *Src = Visit(const_cast<Expr*>(E)); 569 570 // Use EmitScalarConversion to perform the conversion. 571 return EmitScalarConversion(Src, E->getType(), DestTy); 572 } 573 574 if (E->getType()->isAnyComplexType()) { 575 // Handle cases where the source is a complex type. 576 return EmitComplexToScalarConversion(CGF.EmitComplexExpr(E), E->getType(), 577 DestTy); 578 } 579 580 // Okay, this is a cast from an aggregate. It must be a cast to void. Just 581 // evaluate the result and return. 582 CGF.EmitAggExpr(E, 0, false); 583 return 0; 584} 585 586Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 587 return CGF.EmitCompoundStmt(*E->getSubStmt(), true).getScalarVal(); 588} 589 590 591//===----------------------------------------------------------------------===// 592// Unary Operators 593//===----------------------------------------------------------------------===// 594 595Value *ScalarExprEmitter::VisitPrePostIncDec(const UnaryOperator *E, 596 bool isInc, bool isPre) { 597 LValue LV = EmitLValue(E->getSubExpr()); 598 // FIXME: Handle volatile! 599 Value *InVal = CGF.EmitLoadOfLValue(LV, // false 600 E->getSubExpr()->getType()).getScalarVal(); 601 602 int AmountVal = isInc ? 1 : -1; 603 604 Value *NextVal; 605 if (isa<llvm::PointerType>(InVal->getType())) { 606 // FIXME: This isn't right for VLAs. 607 NextVal = llvm::ConstantInt::get(llvm::Type::Int32Ty, AmountVal); 608 NextVal = Builder.CreateGEP(InVal, NextVal, "ptrincdec"); 609 } else { 610 // Add the inc/dec to the real part. 611 if (isa<llvm::IntegerType>(InVal->getType())) 612 NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); 613 else if (InVal->getType() == llvm::Type::FloatTy) 614 NextVal = 615 llvm::ConstantFP::get(llvm::APFloat(static_cast<float>(AmountVal))); 616 else if (InVal->getType() == llvm::Type::DoubleTy) 617 NextVal = 618 llvm::ConstantFP::get(llvm::APFloat(static_cast<double>(AmountVal))); 619 else { 620 llvm::APFloat F(static_cast<float>(AmountVal)); 621 F.convert(*CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero); 622 NextVal = llvm::ConstantFP::get(F); 623 } 624 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 625 } 626 627 // Store the updated result through the lvalue. 628 CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV, 629 E->getSubExpr()->getType()); 630 631 // If this is a postinc, return the value read from memory, otherwise use the 632 // updated value. 633 return isPre ? NextVal : InVal; 634} 635 636 637Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 638 Value *Op = Visit(E->getSubExpr()); 639 return Builder.CreateNeg(Op, "neg"); 640} 641 642Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 643 Value *Op = Visit(E->getSubExpr()); 644 return Builder.CreateNot(Op, "neg"); 645} 646 647Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 648 // Compare operand to zero. 649 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 650 651 // Invert value. 652 // TODO: Could dynamically modify easy computations here. For example, if 653 // the operand is an icmp ne, turn into icmp eq. 654 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 655 656 // ZExt result to int. 657 return Builder.CreateZExt(BoolVal, CGF.LLVMIntTy, "lnot.ext"); 658} 659 660/// EmitSizeAlignOf - Return the size or alignment of the 'TypeToSize' type as 661/// an integer (RetType). 662Value *ScalarExprEmitter::EmitSizeAlignOf(QualType TypeToSize, 663 QualType RetType,bool isSizeOf){ 664 assert(RetType->isIntegerType() && "Result type must be an integer!"); 665 uint32_t ResultWidth = 666 static_cast<uint32_t>(CGF.getContext().getTypeSize(RetType)); 667 668 // sizeof(void) and __alignof__(void) = 1 as a gcc extension. 669 if (TypeToSize->isVoidType()) 670 return llvm::ConstantInt::get(llvm::APInt(ResultWidth, 1)); 671 672 /// FIXME: This doesn't handle VLAs yet! 673 std::pair<uint64_t, unsigned> Info = CGF.getContext().getTypeInfo(TypeToSize); 674 675 uint64_t Val = isSizeOf ? Info.first : Info.second; 676 Val /= 8; // Return size in bytes, not bits. 677 678 return llvm::ConstantInt::get(llvm::APInt(ResultWidth, Val)); 679} 680 681Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 682 Expr *Op = E->getSubExpr(); 683 if (Op->getType()->isAnyComplexType()) 684 return CGF.EmitComplexExpr(Op).first; 685 return Visit(Op); 686} 687Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 688 Expr *Op = E->getSubExpr(); 689 if (Op->getType()->isAnyComplexType()) 690 return CGF.EmitComplexExpr(Op).second; 691 692 // __imag on a scalar returns zero. Emit it the subexpr to ensure side 693 // effects are evaluated. 694 CGF.EmitScalarExpr(Op); 695 return llvm::Constant::getNullValue(ConvertType(E->getType())); 696} 697 698Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) 699{ 700 int64_t Val = E->evaluateOffsetOf(CGF.getContext()); 701 702 assert(E->getType()->isIntegerType() && "Result type must be an integer!"); 703 704 uint32_t ResultWidth = 705 static_cast<uint32_t>(CGF.getContext().getTypeSize(E->getType())); 706 return llvm::ConstantInt::get(llvm::APInt(ResultWidth, Val)); 707} 708 709//===----------------------------------------------------------------------===// 710// Binary Operators 711//===----------------------------------------------------------------------===// 712 713BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 714 BinOpInfo Result; 715 Result.LHS = Visit(E->getLHS()); 716 Result.RHS = Visit(E->getRHS()); 717 Result.Ty = E->getType(); 718 Result.E = E; 719 return Result; 720} 721 722Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 723 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 724 QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType(); 725 726 BinOpInfo OpInfo; 727 728 // Load the LHS and RHS operands. 729 LValue LHSLV = EmitLValue(E->getLHS()); 730 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 731 732 // Determine the computation type. If the RHS is complex, then this is one of 733 // the add/sub/mul/div operators. All of these operators can be computed in 734 // with just their real component even though the computation domain really is 735 // complex. 736 QualType ComputeType = E->getComputationType(); 737 738 // If the computation type is complex, then the RHS is complex. Emit the RHS. 739 if (const ComplexType *CT = ComputeType->getAsComplexType()) { 740 ComputeType = CT->getElementType(); 741 742 // Emit the RHS, only keeping the real component. 743 OpInfo.RHS = CGF.EmitComplexExpr(E->getRHS()).first; 744 RHSTy = RHSTy->getAsComplexType()->getElementType(); 745 } else { 746 // Otherwise the RHS is a simple scalar value. 747 OpInfo.RHS = Visit(E->getRHS()); 748 } 749 750 // Convert the LHS/RHS values to the computation type. 751 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, ComputeType); 752 753 // Do not merge types for -= or += where the LHS is a pointer. 754 if (!(E->getOpcode() == BinaryOperator::SubAssign || 755 E->getOpcode() == BinaryOperator::AddAssign) || 756 !E->getLHS()->getType()->isPointerType()) { 757 OpInfo.RHS = EmitScalarConversion(OpInfo.RHS, RHSTy, ComputeType); 758 } 759 OpInfo.Ty = ComputeType; 760 OpInfo.E = E; 761 762 // Expand the binary operator. 763 Value *Result = (this->*Func)(OpInfo); 764 765 // Truncate the result back to the LHS type. 766 Result = EmitScalarConversion(Result, ComputeType, LHSTy); 767 768 // Store the result value into the LHS lvalue. 769 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, E->getType()); 770 771 // For bitfields, we need the value in the bitfield 772 // FIXME: This adds an extra bitfield load 773 if (LHSLV.isBitfield()) 774 Result = EmitLoadOfLValue(LHSLV, LHSTy); 775 776 return Result; 777} 778 779 780Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 781 if (Ops.LHS->getType()->isFPOrFPVector()) 782 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 783 else if (Ops.Ty->isUnsignedIntegerType()) 784 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 785 else 786 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 787} 788 789Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 790 // Rem in C can't be a floating point type: C99 6.5.5p2. 791 if (Ops.Ty->isUnsignedIntegerType()) 792 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 793 else 794 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 795} 796 797 798Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 799 if (!Ops.Ty->isPointerType()) 800 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 801 802 // FIXME: What about a pointer to a VLA? 803 Value *Ptr, *Idx; 804 Expr *IdxExp; 805 if (isa<llvm::PointerType>(Ops.LHS->getType())) { // pointer + int 806 Ptr = Ops.LHS; 807 Idx = Ops.RHS; 808 IdxExp = Ops.E->getRHS(); 809 } else { // int + pointer 810 Ptr = Ops.RHS; 811 Idx = Ops.LHS; 812 IdxExp = Ops.E->getLHS(); 813 } 814 815 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 816 if (Width < CGF.LLVMPointerWidth) { 817 // Zero or sign extend the pointer value based on whether the index is 818 // signed or not. 819 const llvm::Type *IdxType = llvm::IntegerType::get(CGF.LLVMPointerWidth); 820 if (IdxExp->getType().getCanonicalType()->isSignedIntegerType()) 821 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 822 else 823 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 824 } 825 826 return Builder.CreateGEP(Ptr, Idx, "add.ptr"); 827} 828 829Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 830 if (!isa<llvm::PointerType>(Ops.LHS->getType())) 831 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 832 833 // pointer - int 834 assert(!isa<llvm::PointerType>(Ops.RHS->getType()) && 835 "ptr-ptr shouldn't get here"); 836 // FIXME: The pointer could point to a VLA. 837 Value *Idx = Builder.CreateNeg(Ops.RHS, "sub.ptr.neg"); 838 839 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 840 if (Width < CGF.LLVMPointerWidth) { 841 // Zero or sign extend the pointer value based on whether the index is 842 // signed or not. 843 const llvm::Type *IdxType = llvm::IntegerType::get(CGF.LLVMPointerWidth); 844 if (Ops.E->getRHS()->getType().getCanonicalType()->isSignedIntegerType()) 845 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 846 else 847 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 848 } 849 850 return Builder.CreateGEP(Ops.LHS, Idx, "sub.ptr"); 851} 852 853Value *ScalarExprEmitter::VisitBinSub(const BinaryOperator *E) { 854 // "X - Y" is different from "X -= Y" in one case: when Y is a pointer. In 855 // the compound assignment case it is invalid, so just handle it here. 856 if (!E->getRHS()->getType()->isPointerType()) 857 return EmitSub(EmitBinOps(E)); 858 859 // pointer - pointer 860 Value *LHS = Visit(E->getLHS()); 861 Value *RHS = Visit(E->getRHS()); 862 863 const QualType LHSType = E->getLHS()->getType().getCanonicalType(); 864 const QualType LHSElementType = cast<PointerType>(LHSType)->getPointeeType(); 865 uint64_t ElementSize = CGF.getContext().getTypeSize(LHSElementType) / 8; 866 867 const llvm::Type *ResultType = ConvertType(E->getType()); 868 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 869 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 870 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 871 872 // HACK: LLVM doesn't have an divide instruction that 'knows' there is no 873 // remainder. As such, we handle common power-of-two cases here to generate 874 // better code. 875 if (llvm::isPowerOf2_64(ElementSize)) { 876 Value *ShAmt = 877 llvm::ConstantInt::get(ResultType, llvm::Log2_64(ElementSize)); 878 return Builder.CreateAShr(BytesBetween, ShAmt, "sub.ptr.shr"); 879 } 880 881 // Otherwise, do a full sdiv. 882 Value *BytesPerElt = llvm::ConstantInt::get(ResultType, ElementSize); 883 return Builder.CreateSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 884} 885 886 887Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 888 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 889 // RHS to the same size as the LHS. 890 Value *RHS = Ops.RHS; 891 if (Ops.LHS->getType() != RHS->getType()) 892 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 893 894 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 895} 896 897Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 898 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 899 // RHS to the same size as the LHS. 900 Value *RHS = Ops.RHS; 901 if (Ops.LHS->getType() != RHS->getType()) 902 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 903 904 if (Ops.Ty->isUnsignedIntegerType()) 905 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 906 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 907} 908 909Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 910 unsigned SICmpOpc, unsigned FCmpOpc) { 911 Value *Result; 912 QualType LHSTy = E->getLHS()->getType(); 913 if (!LHSTy->isAnyComplexType()) { 914 Value *LHS = Visit(E->getLHS()); 915 Value *RHS = Visit(E->getRHS()); 916 917 if (LHS->getType()->isFloatingPoint()) { 918 Result = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 919 LHS, RHS, "cmp"); 920 } else if (LHSTy->isSignedIntegerType()) { 921 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 922 LHS, RHS, "cmp"); 923 } else { 924 // Unsigned integers and pointers. 925 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 926 LHS, RHS, "cmp"); 927 } 928 } else { 929 // Complex Comparison: can only be an equality comparison. 930 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 931 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 932 933 QualType CETy = 934 cast<ComplexType>(LHSTy.getCanonicalType())->getElementType(); 935 936 Value *ResultR, *ResultI; 937 if (CETy->isRealFloatingType()) { 938 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 939 LHS.first, RHS.first, "cmp.r"); 940 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 941 LHS.second, RHS.second, "cmp.i"); 942 } else { 943 // Complex comparisons can only be equality comparisons. As such, signed 944 // and unsigned opcodes are the same. 945 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 946 LHS.first, RHS.first, "cmp.r"); 947 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 948 LHS.second, RHS.second, "cmp.i"); 949 } 950 951 if (E->getOpcode() == BinaryOperator::EQ) { 952 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 953 } else { 954 assert(E->getOpcode() == BinaryOperator::NE && 955 "Complex comparison other than == or != ?"); 956 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 957 } 958 } 959 960 // ZExt result to int. 961 return Builder.CreateZExt(Result, CGF.LLVMIntTy, "cmp.ext"); 962} 963 964Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 965 LValue LHS = EmitLValue(E->getLHS()); 966 Value *RHS = Visit(E->getRHS()); 967 968 // Store the value into the LHS. 969 // FIXME: Volatility! 970 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 971 972 // For bitfields, we need the value in the bitfield 973 // FIXME: This adds an extra bitfield load 974 if (LHS.isBitfield()) 975 return EmitLoadOfLValue(LHS, E->getLHS()->getType()); 976 // Return the RHS. 977 return RHS; 978} 979 980Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 981 Value *LHSCond = CGF.EvaluateExprAsBool(E->getLHS()); 982 983 llvm::BasicBlock *ContBlock = llvm::BasicBlock::Create("land_cont"); 984 llvm::BasicBlock *RHSBlock = llvm::BasicBlock::Create("land_rhs"); 985 986 llvm::BasicBlock *OrigBlock = Builder.GetInsertBlock(); 987 Builder.CreateCondBr(LHSCond, RHSBlock, ContBlock); 988 989 CGF.EmitBlock(RHSBlock); 990 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 991 992 // Reaquire the RHS block, as there may be subblocks inserted. 993 RHSBlock = Builder.GetInsertBlock(); 994 CGF.EmitBlock(ContBlock); 995 996 // Create a PHI node. If we just evaluted the LHS condition, the result is 997 // false. If we evaluated both, the result is the RHS condition. 998 llvm::PHINode *PN = Builder.CreatePHI(llvm::Type::Int1Ty, "land"); 999 PN->reserveOperandSpace(2); 1000 PN->addIncoming(llvm::ConstantInt::getFalse(), OrigBlock); 1001 PN->addIncoming(RHSCond, RHSBlock); 1002 1003 // ZExt result to int. 1004 return Builder.CreateZExt(PN, CGF.LLVMIntTy, "land.ext"); 1005} 1006 1007Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 1008 Value *LHSCond = CGF.EvaluateExprAsBool(E->getLHS()); 1009 1010 llvm::BasicBlock *ContBlock = llvm::BasicBlock::Create("lor_cont"); 1011 llvm::BasicBlock *RHSBlock = llvm::BasicBlock::Create("lor_rhs"); 1012 1013 llvm::BasicBlock *OrigBlock = Builder.GetInsertBlock(); 1014 Builder.CreateCondBr(LHSCond, ContBlock, RHSBlock); 1015 1016 CGF.EmitBlock(RHSBlock); 1017 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1018 1019 // Reaquire the RHS block, as there may be subblocks inserted. 1020 RHSBlock = Builder.GetInsertBlock(); 1021 CGF.EmitBlock(ContBlock); 1022 1023 // Create a PHI node. If we just evaluted the LHS condition, the result is 1024 // true. If we evaluated both, the result is the RHS condition. 1025 llvm::PHINode *PN = Builder.CreatePHI(llvm::Type::Int1Ty, "lor"); 1026 PN->reserveOperandSpace(2); 1027 PN->addIncoming(llvm::ConstantInt::getTrue(), OrigBlock); 1028 PN->addIncoming(RHSCond, RHSBlock); 1029 1030 // ZExt result to int. 1031 return Builder.CreateZExt(PN, CGF.LLVMIntTy, "lor.ext"); 1032} 1033 1034Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 1035 CGF.EmitStmt(E->getLHS()); 1036 return Visit(E->getRHS()); 1037} 1038 1039//===----------------------------------------------------------------------===// 1040// Other Operators 1041//===----------------------------------------------------------------------===// 1042 1043Value *ScalarExprEmitter:: 1044VisitConditionalOperator(const ConditionalOperator *E) { 1045 llvm::BasicBlock *LHSBlock = llvm::BasicBlock::Create("cond.?"); 1046 llvm::BasicBlock *RHSBlock = llvm::BasicBlock::Create("cond.:"); 1047 llvm::BasicBlock *ContBlock = llvm::BasicBlock::Create("cond.cont"); 1048 1049 // Evaluate the conditional, then convert it to bool. We do this explicitly 1050 // because we need the unconverted value if this is a GNU ?: expression with 1051 // missing middle value. 1052 Value *CondVal = CGF.EmitScalarExpr(E->getCond()); 1053 Value *CondBoolVal =CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 1054 CGF.getContext().BoolTy); 1055 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 1056 1057 CGF.EmitBlock(LHSBlock); 1058 1059 // Handle the GNU extension for missing LHS. 1060 Value *LHS; 1061 if (E->getLHS()) 1062 LHS = Visit(E->getLHS()); 1063 else // Perform promotions, to handle cases like "short ?: int" 1064 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); 1065 1066 Builder.CreateBr(ContBlock); 1067 LHSBlock = Builder.GetInsertBlock(); 1068 1069 CGF.EmitBlock(RHSBlock); 1070 1071 Value *RHS = Visit(E->getRHS()); 1072 Builder.CreateBr(ContBlock); 1073 RHSBlock = Builder.GetInsertBlock(); 1074 1075 CGF.EmitBlock(ContBlock); 1076 1077 if (!LHS || !RHS) { 1078 assert(E->getType()->isVoidType() && "Non-void value should have a value"); 1079 return 0; 1080 } 1081 1082 // Create a PHI node for the real part. 1083 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 1084 PN->reserveOperandSpace(2); 1085 PN->addIncoming(LHS, LHSBlock); 1086 PN->addIncoming(RHS, RHSBlock); 1087 return PN; 1088} 1089 1090Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 1091 // Emit the LHS or RHS as appropriate. 1092 return 1093 Visit(E->isConditionTrue(CGF.getContext()) ? E->getLHS() : E->getRHS()); 1094} 1095 1096Value *ScalarExprEmitter::VisitOverloadExpr(OverloadExpr *E) { 1097 return CGF.EmitCallExpr(E->getFn(), E->arg_begin(), 1098 E->arg_end(CGF.getContext())).getScalarVal(); 1099} 1100 1101Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 1102 llvm::Value *ArgValue = EmitLValue(VE->getSubExpr()).getAddress(); 1103 1104 llvm::Value *V = Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 1105 return V; 1106} 1107 1108Value *ScalarExprEmitter::VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { 1109 std::string str; 1110 llvm::SmallVector<const RecordType *, 8> EncodingRecordTypes; 1111 CGF.getContext().getObjCEncodingForType(E->getEncodedType(), str, 1112 EncodingRecordTypes); 1113 1114 llvm::Constant *C = llvm::ConstantArray::get(str); 1115 C = new llvm::GlobalVariable(C->getType(), true, 1116 llvm::GlobalValue::InternalLinkage, 1117 C, ".str", &CGF.CGM.getModule()); 1118 llvm::Constant *Zero = llvm::Constant::getNullValue(llvm::Type::Int32Ty); 1119 llvm::Constant *Zeros[] = { Zero, Zero }; 1120 C = llvm::ConstantExpr::getGetElementPtr(C, Zeros, 2); 1121 1122 return C; 1123} 1124 1125//===----------------------------------------------------------------------===// 1126// Entry Point into this File 1127//===----------------------------------------------------------------------===// 1128 1129/// EmitComplexExpr - Emit the computation of the specified expression of 1130/// complex type, ignoring the result. 1131Value *CodeGenFunction::EmitScalarExpr(const Expr *E) { 1132 assert(E && !hasAggregateLLVMType(E->getType()) && 1133 "Invalid scalar expression to emit"); 1134 1135 return ScalarExprEmitter(*this).Visit(const_cast<Expr*>(E)); 1136} 1137 1138/// EmitScalarConversion - Emit a conversion from the specified type to the 1139/// specified destination type, both of which are LLVM scalar types. 1140Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 1141 QualType DstTy) { 1142 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 1143 "Invalid scalar expression to emit"); 1144 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 1145} 1146 1147/// EmitComplexToScalarConversion - Emit a conversion from the specified 1148/// complex type to the specified destination type, where the destination 1149/// type is an LLVM scalar type. 1150Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 1151 QualType SrcTy, 1152 QualType DstTy) { 1153 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 1154 "Invalid complex -> scalar conversion"); 1155 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 1156 DstTy); 1157} 1158 1159Value *CodeGenFunction::EmitShuffleVector(Value* V1, Value *V2, ...) { 1160 assert(V1->getType() == V2->getType() && 1161 "Vector operands must be of the same type"); 1162 1163 unsigned NumElements = 1164 cast<llvm::VectorType>(V1->getType())->getNumElements(); 1165 1166 va_list va; 1167 va_start(va, V2); 1168 1169 llvm::SmallVector<llvm::Constant*, 16> Args; 1170 1171 for (unsigned i = 0; i < NumElements; i++) { 1172 int n = va_arg(va, int); 1173 1174 assert(n >= 0 && n < (int)NumElements * 2 && 1175 "Vector shuffle index out of bounds!"); 1176 1177 Args.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, n)); 1178 } 1179 1180 const char *Name = va_arg(va, const char *); 1181 va_end(va); 1182 1183 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 1184 1185 return Builder.CreateShuffleVector(V1, V2, Mask, Name); 1186} 1187 1188llvm::Value *CodeGenFunction::EmitVector(llvm::Value * const *Vals, 1189 unsigned NumVals, bool isSplat) 1190{ 1191 llvm::Value *Vec 1192 = llvm::UndefValue::get(llvm::VectorType::get(Vals[0]->getType(), NumVals)); 1193 1194 for (unsigned i = 0, e = NumVals ; i != e; ++i) { 1195 llvm::Value *Val = isSplat ? Vals[0] : Vals[i]; 1196 llvm::Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); 1197 Vec = Builder.CreateInsertElement(Vec, Val, Idx, "tmp"); 1198 } 1199 1200 return Vec; 1201} 1202