CGExprScalar.cpp revision 91daf4da934e10dcbf22697d59e2791420b1507a
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 "llvm/Support/CFG.h" 26#include <cstdarg> 27 28using namespace clang; 29using namespace CodeGen; 30using llvm::Value; 31 32//===----------------------------------------------------------------------===// 33// Scalar Expression Emitter 34//===----------------------------------------------------------------------===// 35 36struct BinOpInfo { 37 Value *LHS; 38 Value *RHS; 39 QualType Ty; // Computation Type. 40 const BinaryOperator *E; 41}; 42 43namespace { 44class VISIBILITY_HIDDEN ScalarExprEmitter 45 : public StmtVisitor<ScalarExprEmitter, Value*> { 46 CodeGenFunction &CGF; 47 CGBuilderTy &Builder; 48 49public: 50 51 ScalarExprEmitter(CodeGenFunction &cgf) : CGF(cgf), 52 Builder(CGF.Builder) { 53 } 54 55 //===--------------------------------------------------------------------===// 56 // Utilities 57 //===--------------------------------------------------------------------===// 58 59 const llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); } 60 LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); } 61 62 Value *EmitLoadOfLValue(LValue LV, QualType T) { 63 return CGF.EmitLoadOfLValue(LV, T).getScalarVal(); 64 } 65 66 /// EmitLoadOfLValue - Given an expression with complex type that represents a 67 /// value l-value, this method emits the address of the l-value, then loads 68 /// and returns the result. 69 Value *EmitLoadOfLValue(const Expr *E) { 70 // FIXME: Volatile 71 return EmitLoadOfLValue(EmitLValue(E), E->getType()); 72 } 73 74 /// EmitConversionToBool - Convert the specified expression value to a 75 /// boolean (i1) truth value. This is equivalent to "Val != 0". 76 Value *EmitConversionToBool(Value *Src, QualType DstTy); 77 78 /// EmitScalarConversion - Emit a conversion from the specified type to the 79 /// specified destination type, both of which are LLVM scalar types. 80 Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); 81 82 /// EmitComplexToScalarConversion - Emit a conversion from the specified 83 /// complex type to the specified destination type, where the destination 84 /// type is an LLVM scalar type. 85 Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 86 QualType SrcTy, QualType DstTy); 87 88 //===--------------------------------------------------------------------===// 89 // Visitor Methods 90 //===--------------------------------------------------------------------===// 91 92 Value *VisitStmt(Stmt *S) { 93 S->dump(CGF.getContext().getSourceManager()); 94 assert(0 && "Stmt can't have complex result type!"); 95 return 0; 96 } 97 Value *VisitExpr(Expr *S); 98 Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); } 99 100 // Leaves. 101 Value *VisitIntegerLiteral(const IntegerLiteral *E) { 102 return llvm::ConstantInt::get(E->getValue()); 103 } 104 Value *VisitFloatingLiteral(const FloatingLiteral *E) { 105 return llvm::ConstantFP::get(E->getValue()); 106 } 107 Value *VisitCharacterLiteral(const CharacterLiteral *E) { 108 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 109 } 110 Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { 111 return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); 112 } 113 Value *VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) { 114 return llvm::Constant::getNullValue(ConvertType(E->getType())); 115 } 116 Value *VisitGNUNullExpr(const GNUNullExpr *E) { 117 return llvm::Constant::getNullValue(ConvertType(E->getType())); 118 } 119 Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { 120 return llvm::ConstantInt::get(ConvertType(E->getType()), 121 CGF.getContext().typesAreCompatible( 122 E->getArgType1(), E->getArgType2())); 123 } 124 Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); 125 Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { 126 llvm::Value *V = 127 llvm::ConstantInt::get(llvm::Type::Int32Ty, 128 CGF.GetIDForAddrOfLabel(E->getLabel())); 129 130 return Builder.CreateIntToPtr(V, ConvertType(E->getType())); 131 } 132 133 // l-values. 134 Value *VisitDeclRefExpr(DeclRefExpr *E) { 135 if (const EnumConstantDecl *EC = dyn_cast<EnumConstantDecl>(E->getDecl())) 136 return llvm::ConstantInt::get(EC->getInitVal()); 137 return EmitLoadOfLValue(E); 138 } 139 Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { 140 return CGF.EmitObjCSelectorExpr(E); 141 } 142 Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { 143 return CGF.EmitObjCProtocolExpr(E); 144 } 145 Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 146 return EmitLoadOfLValue(E); 147 } 148 Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { 149 return EmitLoadOfLValue(E); 150 } 151 Value *VisitObjCKVCRefExpr(ObjCKVCRefExpr *E) { 152 return EmitLoadOfLValue(E); 153 } 154 Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { 155 return CGF.EmitObjCMessageExpr(E).getScalarVal(); 156 } 157 158 Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); 159 Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); 160 Value *VisitMemberExpr(Expr *E) { return EmitLoadOfLValue(E); } 161 Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } 162 Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 163 return EmitLoadOfLValue(E); 164 } 165 Value *VisitStringLiteral(Expr *E) { return EmitLValue(E).getAddress(); } 166 Value *VisitPredefinedExpr(Expr *E) { return EmitLValue(E).getAddress(); } 167 168 Value *VisitInitListExpr(InitListExpr *E) { 169 unsigned NumInitElements = E->getNumInits(); 170 171 const llvm::VectorType *VType = 172 dyn_cast<llvm::VectorType>(ConvertType(E->getType())); 173 174 // We have a scalar in braces. Just use the first element. 175 if (!VType) 176 return Visit(E->getInit(0)); 177 178 if (E->hadDesignators()) { 179 CGF.ErrorUnsupported(E, "initializer list with designators"); 180 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 181 } 182 183 unsigned NumVectorElements = VType->getNumElements(); 184 const llvm::Type *ElementType = VType->getElementType(); 185 186 // Emit individual vector element stores. 187 llvm::Value *V = llvm::UndefValue::get(VType); 188 189 // Emit initializers 190 unsigned i; 191 for (i = 0; i < NumInitElements; ++i) { 192 Value *NewV = Visit(E->getInit(i)); 193 Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); 194 V = Builder.CreateInsertElement(V, NewV, Idx); 195 } 196 197 // Emit remaining default initializers 198 for (/* Do not initialize i*/; i < NumVectorElements; ++i) { 199 Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); 200 llvm::Value *NewV = llvm::Constant::getNullValue(ElementType); 201 V = Builder.CreateInsertElement(V, NewV, Idx); 202 } 203 204 return V; 205 } 206 207 Value *VisitImplicitCastExpr(const ImplicitCastExpr *E); 208 Value *VisitCastExpr(const CastExpr *E) { 209 return EmitCastExpr(E->getSubExpr(), E->getType()); 210 } 211 Value *EmitCastExpr(const Expr *E, QualType T); 212 213 Value *VisitCallExpr(const CallExpr *E) { 214 return CGF.EmitCallExpr(E).getScalarVal(); 215 } 216 217 Value *VisitStmtExpr(const StmtExpr *E); 218 219 // Unary Operators. 220 Value *VisitPrePostIncDec(const UnaryOperator *E, bool isInc, bool isPre); 221 Value *VisitUnaryPostDec(const UnaryOperator *E) { 222 return VisitPrePostIncDec(E, false, false); 223 } 224 Value *VisitUnaryPostInc(const UnaryOperator *E) { 225 return VisitPrePostIncDec(E, true, false); 226 } 227 Value *VisitUnaryPreDec(const UnaryOperator *E) { 228 return VisitPrePostIncDec(E, false, true); 229 } 230 Value *VisitUnaryPreInc(const UnaryOperator *E) { 231 return VisitPrePostIncDec(E, true, true); 232 } 233 Value *VisitUnaryAddrOf(const UnaryOperator *E) { 234 return EmitLValue(E->getSubExpr()).getAddress(); 235 } 236 Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } 237 Value *VisitUnaryPlus(const UnaryOperator *E) { 238 return Visit(E->getSubExpr()); 239 } 240 Value *VisitUnaryMinus (const UnaryOperator *E); 241 Value *VisitUnaryNot (const UnaryOperator *E); 242 Value *VisitUnaryLNot (const UnaryOperator *E); 243 Value *VisitUnaryReal (const UnaryOperator *E); 244 Value *VisitUnaryImag (const UnaryOperator *E); 245 Value *VisitUnaryExtension(const UnaryOperator *E) { 246 return Visit(E->getSubExpr()); 247 } 248 Value *VisitUnaryOffsetOf(const UnaryOperator *E); 249 Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 250 return Visit(DAE->getExpr()); 251 } 252 253 // Binary Operators. 254 Value *EmitMul(const BinOpInfo &Ops) { 255 return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); 256 } 257 Value *EmitDiv(const BinOpInfo &Ops); 258 Value *EmitRem(const BinOpInfo &Ops); 259 Value *EmitAdd(const BinOpInfo &Ops); 260 Value *EmitSub(const BinOpInfo &Ops); 261 Value *EmitShl(const BinOpInfo &Ops); 262 Value *EmitShr(const BinOpInfo &Ops); 263 Value *EmitAnd(const BinOpInfo &Ops) { 264 return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); 265 } 266 Value *EmitXor(const BinOpInfo &Ops) { 267 return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); 268 } 269 Value *EmitOr (const BinOpInfo &Ops) { 270 return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); 271 } 272 273 BinOpInfo EmitBinOps(const BinaryOperator *E); 274 Value *EmitCompoundAssign(const CompoundAssignOperator *E, 275 Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); 276 277 // Binary operators and binary compound assignment operators. 278#define HANDLEBINOP(OP) \ 279 Value *VisitBin ## OP(const BinaryOperator *E) { \ 280 return Emit ## OP(EmitBinOps(E)); \ 281 } \ 282 Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ 283 return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ 284 } 285 HANDLEBINOP(Mul); 286 HANDLEBINOP(Div); 287 HANDLEBINOP(Rem); 288 HANDLEBINOP(Add); 289 HANDLEBINOP(Sub); 290 HANDLEBINOP(Shl); 291 HANDLEBINOP(Shr); 292 HANDLEBINOP(And); 293 HANDLEBINOP(Xor); 294 HANDLEBINOP(Or); 295#undef HANDLEBINOP 296 297 // Comparisons. 298 Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, 299 unsigned SICmpOpc, unsigned FCmpOpc); 300#define VISITCOMP(CODE, UI, SI, FP) \ 301 Value *VisitBin##CODE(const BinaryOperator *E) { \ 302 return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ 303 llvm::FCmpInst::FP); } 304 VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT); 305 VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT); 306 VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE); 307 VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE); 308 VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ); 309 VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE); 310#undef VISITCOMP 311 312 Value *VisitBinAssign (const BinaryOperator *E); 313 314 Value *VisitBinLAnd (const BinaryOperator *E); 315 Value *VisitBinLOr (const BinaryOperator *E); 316 Value *VisitBinComma (const BinaryOperator *E); 317 318 // Other Operators. 319 Value *VisitBlockExpr(const BlockExpr *BE) { 320 CGF.ErrorUnsupported(BE, "block expression"); 321 return llvm::UndefValue::get(CGF.ConvertType(BE->getType())); 322 } 323 324 Value *VisitConditionalOperator(const ConditionalOperator *CO); 325 Value *VisitChooseExpr(ChooseExpr *CE); 326 Value *VisitOverloadExpr(OverloadExpr *OE); 327 Value *VisitVAArgExpr(VAArgExpr *VE); 328 Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { 329 return CGF.EmitObjCStringLiteral(E); 330 } 331 Value *VisitObjCEncodeExpr(const ObjCEncodeExpr *E); 332}; 333} // end anonymous namespace. 334 335//===----------------------------------------------------------------------===// 336// Utilities 337//===----------------------------------------------------------------------===// 338 339/// EmitConversionToBool - Convert the specified expression value to a 340/// boolean (i1) truth value. This is equivalent to "Val != 0". 341Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { 342 assert(SrcType->isCanonical() && "EmitScalarConversion strips typedefs"); 343 344 if (SrcType->isRealFloatingType()) { 345 // Compare against 0.0 for fp scalars. 346 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 347 return Builder.CreateFCmpUNE(Src, Zero, "tobool"); 348 } 349 350 assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && 351 "Unknown scalar type to convert"); 352 353 // Because of the type rules of C, we often end up computing a logical value, 354 // then zero extending it to int, then wanting it as a logical value again. 355 // Optimize this common case. 356 if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) { 357 if (ZI->getOperand(0)->getType() == llvm::Type::Int1Ty) { 358 Value *Result = ZI->getOperand(0); 359 // If there aren't any more uses, zap the instruction to save space. 360 // Note that there can be more uses, for example if this 361 // is the result of an assignment. 362 if (ZI->use_empty()) 363 ZI->eraseFromParent(); 364 return Result; 365 } 366 } 367 368 // Compare against an integer or pointer null. 369 llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); 370 return Builder.CreateICmpNE(Src, Zero, "tobool"); 371} 372 373/// EmitScalarConversion - Emit a conversion from the specified type to the 374/// specified destination type, both of which are LLVM scalar types. 375Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, 376 QualType DstType) { 377 SrcType = CGF.getContext().getCanonicalType(SrcType); 378 DstType = CGF.getContext().getCanonicalType(DstType); 379 if (SrcType == DstType) return Src; 380 381 if (DstType->isVoidType()) return 0; 382 383 // Handle conversions to bool first, they are special: comparisons against 0. 384 if (DstType->isBooleanType()) 385 return EmitConversionToBool(Src, SrcType); 386 387 const llvm::Type *DstTy = ConvertType(DstType); 388 389 // Ignore conversions like int -> uint. 390 if (Src->getType() == DstTy) 391 return Src; 392 393 // Handle pointer conversions next: pointers can only be converted 394 // to/from other pointers and integers. Check for pointer types in 395 // terms of LLVM, as some native types (like Obj-C id) may map to a 396 // pointer type. 397 if (isa<llvm::PointerType>(DstTy)) { 398 // The source value may be an integer, or a pointer. 399 if (isa<llvm::PointerType>(Src->getType())) 400 return Builder.CreateBitCast(Src, DstTy, "conv"); 401 assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); 402 return Builder.CreateIntToPtr(Src, DstTy, "conv"); 403 } 404 405 if (isa<llvm::PointerType>(Src->getType())) { 406 // Must be an ptr to int cast. 407 assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); 408 return Builder.CreatePtrToInt(Src, DstTy, "conv"); 409 } 410 411 // A scalar can be splatted to an extended vector of the same element type 412 if (DstType->isExtVectorType() && !isa<VectorType>(SrcType)) { 413 // Cast the scalar to element type 414 QualType EltTy = DstType->getAsExtVectorType()->getElementType(); 415 llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); 416 417 // Insert the element in element zero of an undef vector 418 llvm::Value *UnV = llvm::UndefValue::get(DstTy); 419 llvm::Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, 0); 420 UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); 421 422 // Splat the element across to all elements 423 llvm::SmallVector<llvm::Constant*, 16> Args; 424 unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); 425 for (unsigned i = 0; i < NumElements; i++) 426 Args.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, 0)); 427 428 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 429 llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); 430 return Yay; 431 } 432 433 // Allow bitcast from vector to integer/fp of the same size. 434 if (isa<llvm::VectorType>(Src->getType()) || 435 isa<llvm::VectorType>(DstTy)) 436 return Builder.CreateBitCast(Src, DstTy, "conv"); 437 438 // Finally, we have the arithmetic types: real int/float. 439 if (isa<llvm::IntegerType>(Src->getType())) { 440 bool InputSigned = SrcType->isSignedIntegerType(); 441 if (isa<llvm::IntegerType>(DstTy)) 442 return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); 443 else if (InputSigned) 444 return Builder.CreateSIToFP(Src, DstTy, "conv"); 445 else 446 return Builder.CreateUIToFP(Src, DstTy, "conv"); 447 } 448 449 assert(Src->getType()->isFloatingPoint() && "Unknown real conversion"); 450 if (isa<llvm::IntegerType>(DstTy)) { 451 if (DstType->isSignedIntegerType()) 452 return Builder.CreateFPToSI(Src, DstTy, "conv"); 453 else 454 return Builder.CreateFPToUI(Src, DstTy, "conv"); 455 } 456 457 assert(DstTy->isFloatingPoint() && "Unknown real conversion"); 458 if (DstTy->getTypeID() < Src->getType()->getTypeID()) 459 return Builder.CreateFPTrunc(Src, DstTy, "conv"); 460 else 461 return Builder.CreateFPExt(Src, DstTy, "conv"); 462} 463 464/// EmitComplexToScalarConversion - Emit a conversion from the specified 465/// complex type to the specified destination type, where the destination 466/// type is an LLVM scalar type. 467Value *ScalarExprEmitter:: 468EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, 469 QualType SrcTy, QualType DstTy) { 470 // Get the source element type. 471 SrcTy = SrcTy->getAsComplexType()->getElementType(); 472 473 // Handle conversions to bool first, they are special: comparisons against 0. 474 if (DstTy->isBooleanType()) { 475 // Complex != 0 -> (Real != 0) | (Imag != 0) 476 Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); 477 Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); 478 return Builder.CreateOr(Src.first, Src.second, "tobool"); 479 } 480 481 // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, 482 // the imaginary part of the complex value is discarded and the value of the 483 // real part is converted according to the conversion rules for the 484 // corresponding real type. 485 return EmitScalarConversion(Src.first, SrcTy, DstTy); 486} 487 488 489//===----------------------------------------------------------------------===// 490// Visitor Methods 491//===----------------------------------------------------------------------===// 492 493Value *ScalarExprEmitter::VisitExpr(Expr *E) { 494 CGF.ErrorUnsupported(E, "scalar expression"); 495 if (E->getType()->isVoidType()) 496 return 0; 497 return llvm::UndefValue::get(CGF.ConvertType(E->getType())); 498} 499 500Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { 501 llvm::SmallVector<llvm::Constant*, 32> indices; 502 for (unsigned i = 2; i < E->getNumSubExprs(); i++) { 503 indices.push_back(cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i)))); 504 } 505 Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); 506 Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); 507 Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); 508 return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); 509} 510 511Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 512 // Emit subscript expressions in rvalue context's. For most cases, this just 513 // loads the lvalue formed by the subscript expr. However, we have to be 514 // careful, because the base of a vector subscript is occasionally an rvalue, 515 // so we can't get it as an lvalue. 516 if (!E->getBase()->getType()->isVectorType()) 517 return EmitLoadOfLValue(E); 518 519 // Handle the vector case. The base must be a vector, the index must be an 520 // integer value. 521 Value *Base = Visit(E->getBase()); 522 Value *Idx = Visit(E->getIdx()); 523 524 // FIXME: Convert Idx to i32 type. 525 return Builder.CreateExtractElement(Base, Idx, "vecext"); 526} 527 528/// VisitImplicitCastExpr - Implicit casts are the same as normal casts, but 529/// also handle things like function to pointer-to-function decay, and array to 530/// pointer decay. 531Value *ScalarExprEmitter::VisitImplicitCastExpr(const ImplicitCastExpr *E) { 532 const Expr *Op = E->getSubExpr(); 533 534 // If this is due to array->pointer conversion, emit the array expression as 535 // an l-value. 536 if (Op->getType()->isArrayType()) { 537 // FIXME: For now we assume that all source arrays map to LLVM arrays. This 538 // will not true when we add support for VLAs. 539 Value *V = EmitLValue(Op).getAddress(); // Bitfields can't be arrays. 540 541 if (!Op->getType()->isVariableArrayType()) { 542 assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); 543 assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) 544 ->getElementType()) && 545 "Expected pointer to array"); 546 V = Builder.CreateStructGEP(V, 0, "arraydecay"); 547 } 548 549 // The resultant pointer type can be implicitly casted to other pointer 550 // types as well (e.g. void*) and can be implicitly converted to integer. 551 const llvm::Type *DestTy = ConvertType(E->getType()); 552 if (V->getType() != DestTy) { 553 if (isa<llvm::PointerType>(DestTy)) 554 V = Builder.CreateBitCast(V, DestTy, "ptrconv"); 555 else { 556 assert(isa<llvm::IntegerType>(DestTy) && "Unknown array decay"); 557 V = Builder.CreatePtrToInt(V, DestTy, "ptrconv"); 558 } 559 } 560 return V; 561 562 } else if (E->getType()->isReferenceType()) { 563 return EmitLValue(Op).getAddress(); 564 } 565 566 return EmitCastExpr(Op, E->getType()); 567} 568 569 570// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts 571// have to handle a more broad range of conversions than explicit casts, as they 572// handle things like function to ptr-to-function decay etc. 573Value *ScalarExprEmitter::EmitCastExpr(const Expr *E, QualType DestTy) { 574 // Handle cases where the source is an non-complex type. 575 576 if (!CGF.hasAggregateLLVMType(E->getType())) { 577 Value *Src = Visit(const_cast<Expr*>(E)); 578 579 // Use EmitScalarConversion to perform the conversion. 580 return EmitScalarConversion(Src, E->getType(), DestTy); 581 } 582 583 if (E->getType()->isAnyComplexType()) { 584 // Handle cases where the source is a complex type. 585 return EmitComplexToScalarConversion(CGF.EmitComplexExpr(E), E->getType(), 586 DestTy); 587 } 588 589 // Okay, this is a cast from an aggregate. It must be a cast to void. Just 590 // evaluate the result and return. 591 CGF.EmitAggExpr(E, 0, false); 592 return 0; 593} 594 595Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { 596 return CGF.EmitCompoundStmt(*E->getSubStmt(), 597 !E->getType()->isVoidType()).getScalarVal(); 598} 599 600 601//===----------------------------------------------------------------------===// 602// Unary Operators 603//===----------------------------------------------------------------------===// 604 605Value *ScalarExprEmitter::VisitPrePostIncDec(const UnaryOperator *E, 606 bool isInc, bool isPre) { 607 LValue LV = EmitLValue(E->getSubExpr()); 608 // FIXME: Handle volatile! 609 Value *InVal = CGF.EmitLoadOfLValue(LV, // false 610 E->getSubExpr()->getType()).getScalarVal(); 611 612 int AmountVal = isInc ? 1 : -1; 613 614 Value *NextVal; 615 if (isa<llvm::PointerType>(InVal->getType())) { 616 // FIXME: This isn't right for VLAs. 617 NextVal = llvm::ConstantInt::get(llvm::Type::Int32Ty, AmountVal); 618 NextVal = Builder.CreateGEP(InVal, NextVal, "ptrincdec"); 619 } else { 620 // Add the inc/dec to the real part. 621 if (isa<llvm::IntegerType>(InVal->getType())) 622 NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); 623 else if (InVal->getType() == llvm::Type::FloatTy) 624 NextVal = 625 llvm::ConstantFP::get(llvm::APFloat(static_cast<float>(AmountVal))); 626 else if (InVal->getType() == llvm::Type::DoubleTy) 627 NextVal = 628 llvm::ConstantFP::get(llvm::APFloat(static_cast<double>(AmountVal))); 629 else { 630 llvm::APFloat F(static_cast<float>(AmountVal)); 631 bool ignored; 632 F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, 633 &ignored); 634 NextVal = llvm::ConstantFP::get(F); 635 } 636 NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); 637 } 638 639 // Store the updated result through the lvalue. 640 CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV, 641 E->getSubExpr()->getType()); 642 643 // If this is a postinc, return the value read from memory, otherwise use the 644 // updated value. 645 return isPre ? NextVal : InVal; 646} 647 648 649Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { 650 Value *Op = Visit(E->getSubExpr()); 651 return Builder.CreateNeg(Op, "neg"); 652} 653 654Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { 655 Value *Op = Visit(E->getSubExpr()); 656 return Builder.CreateNot(Op, "neg"); 657} 658 659Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { 660 // Compare operand to zero. 661 Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); 662 663 // Invert value. 664 // TODO: Could dynamically modify easy computations here. For example, if 665 // the operand is an icmp ne, turn into icmp eq. 666 BoolVal = Builder.CreateNot(BoolVal, "lnot"); 667 668 // ZExt result to int. 669 return Builder.CreateZExt(BoolVal, CGF.LLVMIntTy, "lnot.ext"); 670} 671 672/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of 673/// argument of the sizeof expression as an integer. 674Value * 675ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { 676 // Handle alignof with the constant folding logic. alignof always produces a 677 // constant. 678 if (!E->isSizeOf()) { 679 Expr::EvalResult Result; 680 E->Evaluate(Result, CGF.getContext()); 681 return llvm::ConstantInt::get(Result.Val.getInt()); 682 } 683 684 QualType RetType = E->getType(); 685 assert(RetType->isIntegerType() && "Result type must be an integer!"); 686 uint32_t ResultWidth = 687 static_cast<uint32_t>(CGF.getContext().getTypeSize(RetType)); 688 689 // sizeof(void) and sizeof(function) = 1 as a strange gcc extension. 690 QualType TypeToSize = E->getTypeOfArgument(); 691 if (TypeToSize->isVoidType() || TypeToSize->isFunctionType()) 692 return llvm::ConstantInt::get(llvm::APInt(ResultWidth, 1)); 693 694 if (const VariableArrayType *VAT = 695 CGF.getContext().getAsVariableArrayType(TypeToSize)) { 696 if (E->isArgumentType()) { 697 // sizeof(type) - make sure to emit the VLA size. 698 CGF.EmitVLASize(TypeToSize); 699 } 700 return CGF.GetVLASize(VAT); 701 } 702 703 if (TypeToSize->isObjCInterfaceType()) { 704 ObjCInterfaceDecl *OI = TypeToSize->getAsObjCInterfaceType()->getDecl(); 705 RecordDecl *RD = const_cast<RecordDecl*>( 706 CGF.getContext().addRecordToClass(OI)); 707 TypeToSize = CGF.getContext().getTagDeclType(static_cast<TagDecl*>(RD)); 708 } 709 710 uint64_t Val = CGF.getContext().getTypeSize(TypeToSize); 711 // Return size in bytes, not bits. 712 Val /= CGF.getContext().Target.getCharWidth(); 713 714 return llvm::ConstantInt::get(llvm::APInt(ResultWidth, Val)); 715} 716 717Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { 718 Expr *Op = E->getSubExpr(); 719 if (Op->getType()->isAnyComplexType()) 720 return CGF.EmitComplexExpr(Op).first; 721 return Visit(Op); 722} 723Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { 724 Expr *Op = E->getSubExpr(); 725 if (Op->getType()->isAnyComplexType()) 726 return CGF.EmitComplexExpr(Op).second; 727 728 // __imag on a scalar returns zero. Emit it the subexpr to ensure side 729 // effects are evaluated. 730 CGF.EmitScalarExpr(Op); 731 return llvm::Constant::getNullValue(ConvertType(E->getType())); 732} 733 734Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) 735{ 736 int64_t Val = E->evaluateOffsetOf(CGF.getContext()); 737 738 assert(E->getType()->isIntegerType() && "Result type must be an integer!"); 739 740 uint32_t ResultWidth = 741 static_cast<uint32_t>(CGF.getContext().getTypeSize(E->getType())); 742 return llvm::ConstantInt::get(llvm::APInt(ResultWidth, Val)); 743} 744 745//===----------------------------------------------------------------------===// 746// Binary Operators 747//===----------------------------------------------------------------------===// 748 749BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { 750 BinOpInfo Result; 751 Result.LHS = Visit(E->getLHS()); 752 Result.RHS = Visit(E->getRHS()); 753 Result.Ty = E->getType(); 754 Result.E = E; 755 return Result; 756} 757 758Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, 759 Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { 760 QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType(); 761 762 BinOpInfo OpInfo; 763 764 // Load the LHS and RHS operands. 765 LValue LHSLV = EmitLValue(E->getLHS()); 766 OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); 767 768 // Determine the computation type. If the RHS is complex, then this is one of 769 // the add/sub/mul/div operators. All of these operators can be computed in 770 // with just their real component even though the computation domain really is 771 // complex. 772 QualType ComputeType = E->getComputationType(); 773 774 // If the computation type is complex, then the RHS is complex. Emit the RHS. 775 if (const ComplexType *CT = ComputeType->getAsComplexType()) { 776 ComputeType = CT->getElementType(); 777 778 // Emit the RHS, only keeping the real component. 779 OpInfo.RHS = CGF.EmitComplexExpr(E->getRHS()).first; 780 RHSTy = RHSTy->getAsComplexType()->getElementType(); 781 } else { 782 // Otherwise the RHS is a simple scalar value. 783 OpInfo.RHS = Visit(E->getRHS()); 784 } 785 786 QualType LComputeTy, RComputeTy, ResultTy; 787 788 // Compound assignment does not contain enough information about all 789 // the types involved for pointer arithmetic cases. Figure it out 790 // here for now. 791 if (E->getLHS()->getType()->isPointerType()) { 792 // Pointer arithmetic cases: ptr +=,-= int and ptr -= ptr, 793 assert((E->getOpcode() == BinaryOperator::AddAssign || 794 E->getOpcode() == BinaryOperator::SubAssign) && 795 "Invalid compound assignment operator on pointer type."); 796 LComputeTy = E->getLHS()->getType(); 797 798 if (E->getRHS()->getType()->isPointerType()) { 799 // Degenerate case of (ptr -= ptr) allowed by GCC implicit cast 800 // extension, the conversion from the pointer difference back to 801 // the LHS type is handled at the end. 802 assert(E->getOpcode() == BinaryOperator::SubAssign && 803 "Invalid compound assignment operator on pointer type."); 804 RComputeTy = E->getLHS()->getType(); 805 ResultTy = CGF.getContext().getPointerDiffType(); 806 } else { 807 RComputeTy = E->getRHS()->getType(); 808 ResultTy = LComputeTy; 809 } 810 } else if (E->getRHS()->getType()->isPointerType()) { 811 // Degenerate case of (int += ptr) allowed by GCC implicit cast 812 // extension. 813 assert(E->getOpcode() == BinaryOperator::AddAssign && 814 "Invalid compound assignment operator on pointer type."); 815 LComputeTy = E->getLHS()->getType(); 816 RComputeTy = E->getRHS()->getType(); 817 ResultTy = RComputeTy; 818 } else { 819 LComputeTy = RComputeTy = ResultTy = ComputeType; 820 } 821 822 // Convert the LHS/RHS values to the computation type. 823 OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, LComputeTy); 824 OpInfo.RHS = EmitScalarConversion(OpInfo.RHS, RHSTy, RComputeTy); 825 OpInfo.Ty = ResultTy; 826 OpInfo.E = E; 827 828 // Expand the binary operator. 829 Value *Result = (this->*Func)(OpInfo); 830 831 // Convert the result back to the LHS type. 832 Result = EmitScalarConversion(Result, ResultTy, LHSTy); 833 834 // Store the result value into the LHS lvalue. Bit-fields are 835 // handled specially because the result is altered by the store, 836 // i.e., [C99 6.5.16p1] 'An assignment expression has the value of 837 // the left operand after the assignment...'. 838 if (LHSLV.isBitfield()) 839 CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, 840 &Result); 841 else 842 CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); 843 844 return Result; 845} 846 847 848Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { 849 if (Ops.LHS->getType()->isFPOrFPVector()) 850 return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); 851 else if (Ops.Ty->isUnsignedIntegerType()) 852 return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); 853 else 854 return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); 855} 856 857Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { 858 // Rem in C can't be a floating point type: C99 6.5.5p2. 859 if (Ops.Ty->isUnsignedIntegerType()) 860 return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); 861 else 862 return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); 863} 864 865 866Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { 867 if (!Ops.Ty->isPointerType()) 868 return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); 869 870 // FIXME: What about a pointer to a VLA? 871 Value *Ptr, *Idx; 872 Expr *IdxExp; 873 const PointerType *PT; 874 if ((PT = Ops.E->getLHS()->getType()->getAsPointerType())) { 875 Ptr = Ops.LHS; 876 Idx = Ops.RHS; 877 IdxExp = Ops.E->getRHS(); 878 } else { // int + pointer 879 PT = Ops.E->getRHS()->getType()->getAsPointerType(); 880 assert(PT && "Invalid add expr"); 881 Ptr = Ops.RHS; 882 Idx = Ops.LHS; 883 IdxExp = Ops.E->getLHS(); 884 } 885 886 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 887 if (Width < CGF.LLVMPointerWidth) { 888 // Zero or sign extend the pointer value based on whether the index is 889 // signed or not. 890 const llvm::Type *IdxType = llvm::IntegerType::get(CGF.LLVMPointerWidth); 891 if (IdxExp->getType()->isSignedIntegerType()) 892 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 893 else 894 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 895 } 896 897 // Explicitly handle GNU void* and function pointer arithmetic 898 // extensions. The GNU void* casts amount to no-ops since our void* 899 // type is i8*, but this is future proof. 900 const QualType ElementType = PT->getPointeeType(); 901 if (ElementType->isVoidType() || ElementType->isFunctionType()) { 902 const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); 903 Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); 904 Value *Res = Builder.CreateGEP(Casted, Idx, "sub.ptr"); 905 return Builder.CreateBitCast(Res, Ptr->getType()); 906 } 907 908 return Builder.CreateGEP(Ptr, Idx, "add.ptr"); 909} 910 911Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { 912 if (!isa<llvm::PointerType>(Ops.LHS->getType())) 913 return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); 914 915 const QualType LHSType = Ops.E->getLHS()->getType(); 916 const QualType LHSElementType = LHSType->getAsPointerType()->getPointeeType(); 917 if (!isa<llvm::PointerType>(Ops.RHS->getType())) { 918 // pointer - int 919 Value *Idx = Ops.RHS; 920 unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); 921 if (Width < CGF.LLVMPointerWidth) { 922 // Zero or sign extend the pointer value based on whether the index is 923 // signed or not. 924 const llvm::Type *IdxType = llvm::IntegerType::get(CGF.LLVMPointerWidth); 925 if (Ops.E->getRHS()->getType()->isSignedIntegerType()) 926 Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); 927 else 928 Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); 929 } 930 Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); 931 932 // FIXME: The pointer could point to a VLA. 933 934 // Explicitly handle GNU void* and function pointer arithmetic 935 // extensions. The GNU void* casts amount to no-ops since our 936 // void* type is i8*, but this is future proof. 937 if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { 938 const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); 939 Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); 940 Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); 941 return Builder.CreateBitCast(Res, Ops.LHS->getType()); 942 } 943 944 return Builder.CreateGEP(Ops.LHS, Idx, "sub.ptr"); 945 } else { 946 // pointer - pointer 947 Value *LHS = Ops.LHS; 948 Value *RHS = Ops.RHS; 949 950 uint64_t ElementSize; 951 952 // Handle GCC extension for pointer arithmetic on void* types. 953 if (LHSElementType->isVoidType()) { 954 ElementSize = 1; 955 } else { 956 ElementSize = CGF.getContext().getTypeSize(LHSElementType) / 8; 957 } 958 959 const llvm::Type *ResultType = ConvertType(Ops.Ty); 960 LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); 961 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 962 Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); 963 964 // HACK: LLVM doesn't have an divide instruction that 'knows' there is no 965 // remainder. As such, we handle common power-of-two cases here to generate 966 // better code. See PR2247. 967 if (llvm::isPowerOf2_64(ElementSize)) { 968 Value *ShAmt = 969 llvm::ConstantInt::get(ResultType, llvm::Log2_64(ElementSize)); 970 return Builder.CreateAShr(BytesBetween, ShAmt, "sub.ptr.shr"); 971 } 972 973 // Otherwise, do a full sdiv. 974 Value *BytesPerElt = llvm::ConstantInt::get(ResultType, ElementSize); 975 return Builder.CreateSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); 976 } 977} 978 979Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { 980 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 981 // RHS to the same size as the LHS. 982 Value *RHS = Ops.RHS; 983 if (Ops.LHS->getType() != RHS->getType()) 984 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 985 986 return Builder.CreateShl(Ops.LHS, RHS, "shl"); 987} 988 989Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { 990 // LLVM requires the LHS and RHS to be the same type: promote or truncate the 991 // RHS to the same size as the LHS. 992 Value *RHS = Ops.RHS; 993 if (Ops.LHS->getType() != RHS->getType()) 994 RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); 995 996 if (Ops.Ty->isUnsignedIntegerType()) 997 return Builder.CreateLShr(Ops.LHS, RHS, "shr"); 998 return Builder.CreateAShr(Ops.LHS, RHS, "shr"); 999} 1000 1001Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, 1002 unsigned SICmpOpc, unsigned FCmpOpc) { 1003 Value *Result; 1004 QualType LHSTy = E->getLHS()->getType(); 1005 if (!LHSTy->isAnyComplexType() && !LHSTy->isVectorType()) { 1006 Value *LHS = Visit(E->getLHS()); 1007 Value *RHS = Visit(E->getRHS()); 1008 1009 if (LHS->getType()->isFloatingPoint()) { 1010 Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, 1011 LHS, RHS, "cmp"); 1012 } else if (LHSTy->isSignedIntegerType()) { 1013 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, 1014 LHS, RHS, "cmp"); 1015 } else { 1016 // Unsigned integers and pointers. 1017 Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1018 LHS, RHS, "cmp"); 1019 } 1020 } else if (LHSTy->isVectorType()) { 1021 Value *LHS = Visit(E->getLHS()); 1022 Value *RHS = Visit(E->getRHS()); 1023 1024 if (LHS->getType()->isFPOrFPVector()) { 1025 Result = Builder.CreateVFCmp((llvm::CmpInst::Predicate)FCmpOpc, 1026 LHS, RHS, "cmp"); 1027 } else if (LHSTy->isUnsignedIntegerType()) { 1028 Result = Builder.CreateVICmp((llvm::CmpInst::Predicate)UICmpOpc, 1029 LHS, RHS, "cmp"); 1030 } else { 1031 // Signed integers and pointers. 1032 Result = Builder.CreateVICmp((llvm::CmpInst::Predicate)SICmpOpc, 1033 LHS, RHS, "cmp"); 1034 } 1035 return Result; 1036 } else { 1037 // Complex Comparison: can only be an equality comparison. 1038 CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); 1039 CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); 1040 1041 QualType CETy = LHSTy->getAsComplexType()->getElementType(); 1042 1043 Value *ResultR, *ResultI; 1044 if (CETy->isRealFloatingType()) { 1045 ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1046 LHS.first, RHS.first, "cmp.r"); 1047 ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, 1048 LHS.second, RHS.second, "cmp.i"); 1049 } else { 1050 // Complex comparisons can only be equality comparisons. As such, signed 1051 // and unsigned opcodes are the same. 1052 ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1053 LHS.first, RHS.first, "cmp.r"); 1054 ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, 1055 LHS.second, RHS.second, "cmp.i"); 1056 } 1057 1058 if (E->getOpcode() == BinaryOperator::EQ) { 1059 Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); 1060 } else { 1061 assert(E->getOpcode() == BinaryOperator::NE && 1062 "Complex comparison other than == or != ?"); 1063 Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); 1064 } 1065 } 1066 1067 return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); 1068} 1069 1070Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { 1071 LValue LHS = EmitLValue(E->getLHS()); 1072 Value *RHS = Visit(E->getRHS()); 1073 1074 // Store the value into the LHS. Bit-fields are handled specially 1075 // because the result is altered by the store, i.e., [C99 6.5.16p1] 1076 // 'An assignment expression has the value of the left operand after 1077 // the assignment...'. 1078 // FIXME: Volatility! 1079 if (LHS.isBitfield()) 1080 CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), 1081 &RHS); 1082 else 1083 CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); 1084 1085 // Return the RHS. 1086 return RHS; 1087} 1088 1089Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { 1090 // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. 1091 // If we have 1 && X, just emit X without inserting the control flow. 1092 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1093 if (Cond == 1) { // If we have 1 && X, just emit X. 1094 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1095 // ZExt result to int. 1096 return Builder.CreateZExt(RHSCond, CGF.LLVMIntTy, "land.ext"); 1097 } 1098 1099 // 0 && RHS: If it is safe, just elide the RHS, and return 0. 1100 if (!CGF.ContainsLabel(E->getRHS())) 1101 return llvm::Constant::getNullValue(CGF.LLVMIntTy); 1102 } 1103 1104 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); 1105 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); 1106 1107 // Branch on the LHS first. If it is false, go to the failure (cont) block. 1108 CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); 1109 1110 // Any edges into the ContBlock are now from an (indeterminate number of) 1111 // edges from this first condition. All of these values will be false. Start 1112 // setting up the PHI node in the Cont Block for this. 1113 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::Int1Ty, "", ContBlock); 1114 PN->reserveOperandSpace(2); // Normal case, two inputs. 1115 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1116 PI != PE; ++PI) 1117 PN->addIncoming(llvm::ConstantInt::getFalse(), *PI); 1118 1119 CGF.EmitBlock(RHSBlock); 1120 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1121 1122 // Reaquire the RHS block, as there may be subblocks inserted. 1123 RHSBlock = Builder.GetInsertBlock(); 1124 1125 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1126 // into the phi node for the edge with the value of RHSCond. 1127 CGF.EmitBlock(ContBlock); 1128 PN->addIncoming(RHSCond, RHSBlock); 1129 1130 // ZExt result to int. 1131 return Builder.CreateZExt(PN, CGF.LLVMIntTy, "land.ext"); 1132} 1133 1134Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { 1135 // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. 1136 // If we have 0 || X, just emit X without inserting the control flow. 1137 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { 1138 if (Cond == -1) { // If we have 0 || X, just emit X. 1139 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1140 // ZExt result to int. 1141 return Builder.CreateZExt(RHSCond, CGF.LLVMIntTy, "lor.ext"); 1142 } 1143 1144 // 1 || RHS: If it is safe, just elide the RHS, and return 1. 1145 if (!CGF.ContainsLabel(E->getRHS())) 1146 return llvm::ConstantInt::get(CGF.LLVMIntTy, 1); 1147 } 1148 1149 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); 1150 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); 1151 1152 // Branch on the LHS first. If it is true, go to the success (cont) block. 1153 CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); 1154 1155 // Any edges into the ContBlock are now from an (indeterminate number of) 1156 // edges from this first condition. All of these values will be true. Start 1157 // setting up the PHI node in the Cont Block for this. 1158 llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::Int1Ty, "", ContBlock); 1159 PN->reserveOperandSpace(2); // Normal case, two inputs. 1160 for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); 1161 PI != PE; ++PI) 1162 PN->addIncoming(llvm::ConstantInt::getTrue(), *PI); 1163 1164 // Emit the RHS condition as a bool value. 1165 CGF.EmitBlock(RHSBlock); 1166 Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); 1167 1168 // Reaquire the RHS block, as there may be subblocks inserted. 1169 RHSBlock = Builder.GetInsertBlock(); 1170 1171 // Emit an unconditional branch from this block to ContBlock. Insert an entry 1172 // into the phi node for the edge with the value of RHSCond. 1173 CGF.EmitBlock(ContBlock); 1174 PN->addIncoming(RHSCond, RHSBlock); 1175 1176 // ZExt result to int. 1177 return Builder.CreateZExt(PN, CGF.LLVMIntTy, "lor.ext"); 1178} 1179 1180Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { 1181 CGF.EmitStmt(E->getLHS()); 1182 CGF.EnsureInsertPoint(); 1183 return Visit(E->getRHS()); 1184} 1185 1186//===----------------------------------------------------------------------===// 1187// Other Operators 1188//===----------------------------------------------------------------------===// 1189 1190/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified 1191/// expression is cheap enough and side-effect-free enough to evaluate 1192/// unconditionally instead of conditionally. This is used to convert control 1193/// flow into selects in some cases. 1194static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E) { 1195 if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) 1196 return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr()); 1197 1198 // TODO: Allow anything we can constant fold to an integer or fp constant. 1199 if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || 1200 isa<FloatingLiteral>(E)) 1201 return true; 1202 1203 // Non-volatile automatic variables too, to get "cond ? X : Y" where 1204 // X and Y are local variables. 1205 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 1206 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) 1207 if (VD->hasLocalStorage() && !VD->getType().isVolatileQualified()) 1208 return true; 1209 1210 return false; 1211} 1212 1213 1214Value *ScalarExprEmitter:: 1215VisitConditionalOperator(const ConditionalOperator *E) { 1216 // If the condition constant folds and can be elided, try to avoid emitting 1217 // the condition and the dead arm. 1218 if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ 1219 Expr *Live = E->getLHS(), *Dead = E->getRHS(); 1220 if (Cond == -1) 1221 std::swap(Live, Dead); 1222 1223 // If the dead side doesn't have labels we need, and if the Live side isn't 1224 // the gnu missing ?: extension (which we could handle, but don't bother 1225 // to), just emit the Live part. 1226 if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part 1227 Live) // Live part isn't missing. 1228 return Visit(Live); 1229 } 1230 1231 1232 // If this is a really simple expression (like x ? 4 : 5), emit this as a 1233 // select instead of as control flow. We can only do this if it is cheap and 1234 // safe to evaluate the LHS and RHS unconditionally. 1235 if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS()) && 1236 isCheapEnoughToEvaluateUnconditionally(E->getRHS())) { 1237 llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); 1238 llvm::Value *LHS = Visit(E->getLHS()); 1239 llvm::Value *RHS = Visit(E->getRHS()); 1240 return Builder.CreateSelect(CondV, LHS, RHS, "cond"); 1241 } 1242 1243 1244 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 1245 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 1246 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 1247 Value *CondVal = 0; 1248 1249 // If we have the GNU missing condition extension, evaluate the conditional 1250 // and then convert it to bool the hard way. We do this explicitly 1251 // because we need the unconverted value for the missing middle value of 1252 // the ?:. 1253 if (E->getLHS() == 0) { 1254 CondVal = CGF.EmitScalarExpr(E->getCond()); 1255 Value *CondBoolVal = 1256 CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), 1257 CGF.getContext().BoolTy); 1258 Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); 1259 } else { 1260 // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for 1261 // the branch on bool. 1262 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); 1263 } 1264 1265 CGF.EmitBlock(LHSBlock); 1266 1267 // Handle the GNU extension for missing LHS. 1268 Value *LHS; 1269 if (E->getLHS()) 1270 LHS = Visit(E->getLHS()); 1271 else // Perform promotions, to handle cases like "short ?: int" 1272 LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); 1273 1274 LHSBlock = Builder.GetInsertBlock(); 1275 CGF.EmitBranch(ContBlock); 1276 1277 CGF.EmitBlock(RHSBlock); 1278 1279 Value *RHS = Visit(E->getRHS()); 1280 RHSBlock = Builder.GetInsertBlock(); 1281 CGF.EmitBranch(ContBlock); 1282 1283 CGF.EmitBlock(ContBlock); 1284 1285 if (!LHS || !RHS) { 1286 assert(E->getType()->isVoidType() && "Non-void value should have a value"); 1287 return 0; 1288 } 1289 1290 // Create a PHI node for the real part. 1291 llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); 1292 PN->reserveOperandSpace(2); 1293 PN->addIncoming(LHS, LHSBlock); 1294 PN->addIncoming(RHS, RHSBlock); 1295 return PN; 1296} 1297 1298Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { 1299 // Emit the LHS or RHS as appropriate. 1300 return 1301 Visit(E->isConditionTrue(CGF.getContext()) ? E->getLHS() : E->getRHS()); 1302} 1303 1304Value *ScalarExprEmitter::VisitOverloadExpr(OverloadExpr *E) { 1305 return CGF.EmitCallExpr(E->getFn(), E->arg_begin(), 1306 E->arg_end(CGF.getContext())).getScalarVal(); 1307} 1308 1309Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 1310 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 1311 1312 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 1313 1314 // If EmitVAArg fails, we fall back to the LLVM instruction. 1315 if (!ArgPtr) 1316 return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); 1317 1318 // FIXME: volatile? 1319 return Builder.CreateLoad(ArgPtr); 1320} 1321 1322Value *ScalarExprEmitter::VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { 1323 std::string str; 1324 CGF.getContext().getObjCEncodingForType(E->getEncodedType(), str); 1325 1326 llvm::Constant *C = llvm::ConstantArray::get(str); 1327 C = new llvm::GlobalVariable(C->getType(), true, 1328 llvm::GlobalValue::InternalLinkage, 1329 C, ".str", &CGF.CGM.getModule()); 1330 llvm::Constant *Zero = llvm::Constant::getNullValue(llvm::Type::Int32Ty); 1331 llvm::Constant *Zeros[] = { Zero, Zero }; 1332 C = llvm::ConstantExpr::getGetElementPtr(C, Zeros, 2); 1333 1334 return C; 1335} 1336 1337//===----------------------------------------------------------------------===// 1338// Entry Point into this File 1339//===----------------------------------------------------------------------===// 1340 1341/// EmitComplexExpr - Emit the computation of the specified expression of 1342/// complex type, ignoring the result. 1343Value *CodeGenFunction::EmitScalarExpr(const Expr *E) { 1344 assert(E && !hasAggregateLLVMType(E->getType()) && 1345 "Invalid scalar expression to emit"); 1346 1347 return ScalarExprEmitter(*this).Visit(const_cast<Expr*>(E)); 1348} 1349 1350/// EmitScalarConversion - Emit a conversion from the specified type to the 1351/// specified destination type, both of which are LLVM scalar types. 1352Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, 1353 QualType DstTy) { 1354 assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && 1355 "Invalid scalar expression to emit"); 1356 return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); 1357} 1358 1359/// EmitComplexToScalarConversion - Emit a conversion from the specified 1360/// complex type to the specified destination type, where the destination 1361/// type is an LLVM scalar type. 1362Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, 1363 QualType SrcTy, 1364 QualType DstTy) { 1365 assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && 1366 "Invalid complex -> scalar conversion"); 1367 return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, 1368 DstTy); 1369} 1370 1371Value *CodeGenFunction::EmitShuffleVector(Value* V1, Value *V2, ...) { 1372 assert(V1->getType() == V2->getType() && 1373 "Vector operands must be of the same type"); 1374 unsigned NumElements = 1375 cast<llvm::VectorType>(V1->getType())->getNumElements(); 1376 1377 va_list va; 1378 va_start(va, V2); 1379 1380 llvm::SmallVector<llvm::Constant*, 16> Args; 1381 for (unsigned i = 0; i < NumElements; i++) { 1382 int n = va_arg(va, int); 1383 assert(n >= 0 && n < (int)NumElements * 2 && 1384 "Vector shuffle index out of bounds!"); 1385 Args.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, n)); 1386 } 1387 1388 const char *Name = va_arg(va, const char *); 1389 va_end(va); 1390 1391 llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); 1392 1393 return Builder.CreateShuffleVector(V1, V2, Mask, Name); 1394} 1395 1396llvm::Value *CodeGenFunction::EmitVector(llvm::Value * const *Vals, 1397 unsigned NumVals, bool isSplat) { 1398 llvm::Value *Vec 1399 = llvm::UndefValue::get(llvm::VectorType::get(Vals[0]->getType(), NumVals)); 1400 1401 for (unsigned i = 0, e = NumVals; i != e; ++i) { 1402 llvm::Value *Val = isSplat ? Vals[0] : Vals[i]; 1403 llvm::Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); 1404 Vec = Builder.CreateInsertElement(Vec, Val, Idx, "tmp"); 1405 } 1406 1407 return Vec; 1408} 1409