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      1 //===--- CGExprComplex.cpp - Emit LLVM Code for Complex 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 complex 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/StmtVisitor.h"
     18 #include "llvm/ADT/STLExtras.h"
     19 #include "llvm/ADT/SmallString.h"
     20 #include "llvm/IR/Constants.h"
     21 #include "llvm/IR/Function.h"
     22 #include "llvm/IR/Instructions.h"
     23 #include "llvm/IR/MDBuilder.h"
     24 #include "llvm/IR/Metadata.h"
     25 #include <algorithm>
     26 using namespace clang;
     27 using namespace CodeGen;
     28 
     29 //===----------------------------------------------------------------------===//
     30 //                        Complex Expression Emitter
     31 //===----------------------------------------------------------------------===//
     32 
     33 typedef CodeGenFunction::ComplexPairTy ComplexPairTy;
     34 
     35 /// Return the complex type that we are meant to emit.
     36 static const ComplexType *getComplexType(QualType type) {
     37   type = type.getCanonicalType();
     38   if (const ComplexType *comp = dyn_cast<ComplexType>(type)) {
     39     return comp;
     40   } else {
     41     return cast<ComplexType>(cast<AtomicType>(type)->getValueType());
     42   }
     43 }
     44 
     45 namespace  {
     46 class ComplexExprEmitter
     47   : public StmtVisitor<ComplexExprEmitter, ComplexPairTy> {
     48   CodeGenFunction &CGF;
     49   CGBuilderTy &Builder;
     50   bool IgnoreReal;
     51   bool IgnoreImag;
     52 public:
     53   ComplexExprEmitter(CodeGenFunction &cgf, bool ir=false, bool ii=false)
     54     : CGF(cgf), Builder(CGF.Builder), IgnoreReal(ir), IgnoreImag(ii) {
     55   }
     56 
     57 
     58   //===--------------------------------------------------------------------===//
     59   //                               Utilities
     60   //===--------------------------------------------------------------------===//
     61 
     62   bool TestAndClearIgnoreReal() {
     63     bool I = IgnoreReal;
     64     IgnoreReal = false;
     65     return I;
     66   }
     67   bool TestAndClearIgnoreImag() {
     68     bool I = IgnoreImag;
     69     IgnoreImag = false;
     70     return I;
     71   }
     72 
     73   /// EmitLoadOfLValue - Given an expression with complex type that represents a
     74   /// value l-value, this method emits the address of the l-value, then loads
     75   /// and returns the result.
     76   ComplexPairTy EmitLoadOfLValue(const Expr *E) {
     77     return EmitLoadOfLValue(CGF.EmitLValue(E), E->getExprLoc());
     78   }
     79 
     80   ComplexPairTy EmitLoadOfLValue(LValue LV, SourceLocation Loc);
     81 
     82   /// EmitStoreOfComplex - Store the specified real/imag parts into the
     83   /// specified value pointer.
     84   void EmitStoreOfComplex(ComplexPairTy Val, LValue LV, bool isInit);
     85 
     86   /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
     87   ComplexPairTy EmitComplexToComplexCast(ComplexPairTy Val, QualType SrcType,
     88                                          QualType DestType);
     89   /// EmitComplexToComplexCast - Emit a cast from scalar value Val to DestType.
     90   ComplexPairTy EmitScalarToComplexCast(llvm::Value *Val, QualType SrcType,
     91                                         QualType DestType);
     92 
     93   //===--------------------------------------------------------------------===//
     94   //                            Visitor Methods
     95   //===--------------------------------------------------------------------===//
     96 
     97   ComplexPairTy Visit(Expr *E) {
     98     ApplyDebugLocation DL(CGF, E);
     99     return StmtVisitor<ComplexExprEmitter, ComplexPairTy>::Visit(E);
    100   }
    101 
    102   ComplexPairTy VisitStmt(Stmt *S) {
    103     S->dump(CGF.getContext().getSourceManager());
    104     llvm_unreachable("Stmt can't have complex result type!");
    105   }
    106   ComplexPairTy VisitExpr(Expr *S);
    107   ComplexPairTy VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr());}
    108   ComplexPairTy VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
    109     return Visit(GE->getResultExpr());
    110   }
    111   ComplexPairTy VisitImaginaryLiteral(const ImaginaryLiteral *IL);
    112   ComplexPairTy
    113   VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *PE) {
    114     return Visit(PE->getReplacement());
    115   }
    116 
    117   // l-values.
    118   ComplexPairTy VisitDeclRefExpr(DeclRefExpr *E) {
    119     if (CodeGenFunction::ConstantEmission result = CGF.tryEmitAsConstant(E)) {
    120       if (result.isReference())
    121         return EmitLoadOfLValue(result.getReferenceLValue(CGF, E),
    122                                 E->getExprLoc());
    123 
    124       llvm::Constant *pair = result.getValue();
    125       return ComplexPairTy(pair->getAggregateElement(0U),
    126                            pair->getAggregateElement(1U));
    127     }
    128     return EmitLoadOfLValue(E);
    129   }
    130   ComplexPairTy VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
    131     return EmitLoadOfLValue(E);
    132   }
    133   ComplexPairTy VisitObjCMessageExpr(ObjCMessageExpr *E) {
    134     return CGF.EmitObjCMessageExpr(E).getComplexVal();
    135   }
    136   ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
    137   ComplexPairTy VisitMemberExpr(const Expr *E) { return EmitLoadOfLValue(E); }
    138   ComplexPairTy VisitOpaqueValueExpr(OpaqueValueExpr *E) {
    139     if (E->isGLValue())
    140       return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E), E->getExprLoc());
    141     return CGF.getOpaqueRValueMapping(E).getComplexVal();
    142   }
    143 
    144   ComplexPairTy VisitPseudoObjectExpr(PseudoObjectExpr *E) {
    145     return CGF.EmitPseudoObjectRValue(E).getComplexVal();
    146   }
    147 
    148   // FIXME: CompoundLiteralExpr
    149 
    150   ComplexPairTy EmitCast(CastKind CK, Expr *Op, QualType DestTy);
    151   ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
    152     // Unlike for scalars, we don't have to worry about function->ptr demotion
    153     // here.
    154     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
    155   }
    156   ComplexPairTy VisitCastExpr(CastExpr *E) {
    157     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
    158   }
    159   ComplexPairTy VisitCallExpr(const CallExpr *E);
    160   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
    161 
    162   // Operators.
    163   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
    164                                    bool isInc, bool isPre) {
    165     LValue LV = CGF.EmitLValue(E->getSubExpr());
    166     return CGF.EmitComplexPrePostIncDec(E, LV, isInc, isPre);
    167   }
    168   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
    169     return VisitPrePostIncDec(E, false, false);
    170   }
    171   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
    172     return VisitPrePostIncDec(E, true, false);
    173   }
    174   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
    175     return VisitPrePostIncDec(E, false, true);
    176   }
    177   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
    178     return VisitPrePostIncDec(E, true, true);
    179   }
    180   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
    181   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
    182     TestAndClearIgnoreReal();
    183     TestAndClearIgnoreImag();
    184     return Visit(E->getSubExpr());
    185   }
    186   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
    187   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
    188   // LNot,Real,Imag never return complex.
    189   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
    190     return Visit(E->getSubExpr());
    191   }
    192   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
    193     return Visit(DAE->getExpr());
    194   }
    195   ComplexPairTy VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
    196     CodeGenFunction::CXXDefaultInitExprScope Scope(CGF);
    197     return Visit(DIE->getExpr());
    198   }
    199   ComplexPairTy VisitExprWithCleanups(ExprWithCleanups *E) {
    200     CGF.enterFullExpression(E);
    201     CodeGenFunction::RunCleanupsScope Scope(CGF);
    202     return Visit(E->getSubExpr());
    203   }
    204   ComplexPairTy VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
    205     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
    206     QualType Elem = E->getType()->castAs<ComplexType>()->getElementType();
    207     llvm::Constant *Null = llvm::Constant::getNullValue(CGF.ConvertType(Elem));
    208     return ComplexPairTy(Null, Null);
    209   }
    210   ComplexPairTy VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
    211     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
    212     QualType Elem = E->getType()->castAs<ComplexType>()->getElementType();
    213     llvm::Constant *Null =
    214                        llvm::Constant::getNullValue(CGF.ConvertType(Elem));
    215     return ComplexPairTy(Null, Null);
    216   }
    217 
    218   struct BinOpInfo {
    219     ComplexPairTy LHS;
    220     ComplexPairTy RHS;
    221     QualType Ty;  // Computation Type.
    222   };
    223 
    224   BinOpInfo EmitBinOps(const BinaryOperator *E);
    225   LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
    226                                   ComplexPairTy (ComplexExprEmitter::*Func)
    227                                   (const BinOpInfo &),
    228                                   RValue &Val);
    229   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
    230                                    ComplexPairTy (ComplexExprEmitter::*Func)
    231                                    (const BinOpInfo &));
    232 
    233   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
    234   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
    235   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
    236   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
    237 
    238   ComplexPairTy EmitComplexBinOpLibCall(StringRef LibCallName,
    239                                         const BinOpInfo &Op);
    240 
    241   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
    242     return EmitBinAdd(EmitBinOps(E));
    243   }
    244   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
    245     return EmitBinSub(EmitBinOps(E));
    246   }
    247   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
    248     return EmitBinMul(EmitBinOps(E));
    249   }
    250   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
    251     return EmitBinDiv(EmitBinOps(E));
    252   }
    253 
    254   // Compound assignments.
    255   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
    256     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
    257   }
    258   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
    259     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
    260   }
    261   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
    262     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
    263   }
    264   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
    265     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
    266   }
    267 
    268   // GCC rejects rem/and/or/xor for integer complex.
    269   // Logical and/or always return int, never complex.
    270 
    271   // No comparisons produce a complex result.
    272 
    273   LValue EmitBinAssignLValue(const BinaryOperator *E,
    274                              ComplexPairTy &Val);
    275   ComplexPairTy VisitBinAssign     (const BinaryOperator *E);
    276   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
    277 
    278 
    279   ComplexPairTy
    280   VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
    281   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
    282 
    283   ComplexPairTy VisitInitListExpr(InitListExpr *E);
    284 
    285   ComplexPairTy VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
    286     return EmitLoadOfLValue(E);
    287   }
    288 
    289   ComplexPairTy VisitVAArgExpr(VAArgExpr *E);
    290 
    291   ComplexPairTy VisitAtomicExpr(AtomicExpr *E) {
    292     return CGF.EmitAtomicExpr(E).getComplexVal();
    293   }
    294 };
    295 }  // end anonymous namespace.
    296 
    297 //===----------------------------------------------------------------------===//
    298 //                                Utilities
    299 //===----------------------------------------------------------------------===//
    300 
    301 /// EmitLoadOfLValue - Given an RValue reference for a complex, emit code to
    302 /// load the real and imaginary pieces, returning them as Real/Imag.
    303 ComplexPairTy ComplexExprEmitter::EmitLoadOfLValue(LValue lvalue,
    304                                                    SourceLocation loc) {
    305   assert(lvalue.isSimple() && "non-simple complex l-value?");
    306   if (lvalue.getType()->isAtomicType())
    307     return CGF.EmitAtomicLoad(lvalue, loc).getComplexVal();
    308 
    309   llvm::Value *SrcPtr = lvalue.getAddress();
    310   bool isVolatile = lvalue.isVolatileQualified();
    311   unsigned AlignR = lvalue.getAlignment().getQuantity();
    312   ASTContext &C = CGF.getContext();
    313   QualType ComplexTy = lvalue.getType();
    314   unsigned ComplexAlign = C.getTypeAlignInChars(ComplexTy).getQuantity();
    315   unsigned AlignI = std::min(AlignR, ComplexAlign);
    316 
    317   llvm::Value *Real=nullptr, *Imag=nullptr;
    318 
    319   if (!IgnoreReal || isVolatile) {
    320     llvm::Value *RealP = Builder.CreateStructGEP(nullptr, SrcPtr, 0,
    321                                                  SrcPtr->getName() + ".realp");
    322     Real = Builder.CreateAlignedLoad(RealP, AlignR, isVolatile,
    323                                      SrcPtr->getName() + ".real");
    324   }
    325 
    326   if (!IgnoreImag || isVolatile) {
    327     llvm::Value *ImagP = Builder.CreateStructGEP(nullptr, SrcPtr, 1,
    328                                                  SrcPtr->getName() + ".imagp");
    329     Imag = Builder.CreateAlignedLoad(ImagP, AlignI, isVolatile,
    330                                      SrcPtr->getName() + ".imag");
    331   }
    332   return ComplexPairTy(Real, Imag);
    333 }
    334 
    335 /// EmitStoreOfComplex - Store the specified real/imag parts into the
    336 /// specified value pointer.
    337 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, LValue lvalue,
    338                                             bool isInit) {
    339   if (lvalue.getType()->isAtomicType() ||
    340       (!isInit && CGF.LValueIsSuitableForInlineAtomic(lvalue)))
    341     return CGF.EmitAtomicStore(RValue::getComplex(Val), lvalue, isInit);
    342 
    343   llvm::Value *Ptr = lvalue.getAddress();
    344   llvm::Value *RealPtr = Builder.CreateStructGEP(nullptr, Ptr, 0, "real");
    345   llvm::Value *ImagPtr = Builder.CreateStructGEP(nullptr, Ptr, 1, "imag");
    346   unsigned AlignR = lvalue.getAlignment().getQuantity();
    347   ASTContext &C = CGF.getContext();
    348   QualType ComplexTy = lvalue.getType();
    349   unsigned ComplexAlign = C.getTypeAlignInChars(ComplexTy).getQuantity();
    350   unsigned AlignI = std::min(AlignR, ComplexAlign);
    351 
    352   Builder.CreateAlignedStore(Val.first, RealPtr, AlignR,
    353                              lvalue.isVolatileQualified());
    354   Builder.CreateAlignedStore(Val.second, ImagPtr, AlignI,
    355                              lvalue.isVolatileQualified());
    356 }
    357 
    358 
    359 
    360 //===----------------------------------------------------------------------===//
    361 //                            Visitor Methods
    362 //===----------------------------------------------------------------------===//
    363 
    364 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
    365   CGF.ErrorUnsupported(E, "complex expression");
    366   llvm::Type *EltTy =
    367     CGF.ConvertType(getComplexType(E->getType())->getElementType());
    368   llvm::Value *U = llvm::UndefValue::get(EltTy);
    369   return ComplexPairTy(U, U);
    370 }
    371 
    372 ComplexPairTy ComplexExprEmitter::
    373 VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
    374   llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
    375   return ComplexPairTy(llvm::Constant::getNullValue(Imag->getType()), Imag);
    376 }
    377 
    378 
    379 ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
    380   if (E->getCallReturnType(CGF.getContext())->isReferenceType())
    381     return EmitLoadOfLValue(E);
    382 
    383   return CGF.EmitCallExpr(E).getComplexVal();
    384 }
    385 
    386 ComplexPairTy ComplexExprEmitter::VisitStmtExpr(const StmtExpr *E) {
    387   CodeGenFunction::StmtExprEvaluation eval(CGF);
    388   llvm::Value *RetAlloca = CGF.EmitCompoundStmt(*E->getSubStmt(), true);
    389   assert(RetAlloca && "Expected complex return value");
    390   return EmitLoadOfLValue(CGF.MakeAddrLValue(RetAlloca, E->getType()),
    391                           E->getExprLoc());
    392 }
    393 
    394 /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
    395 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
    396                                                            QualType SrcType,
    397                                                            QualType DestType) {
    398   // Get the src/dest element type.
    399   SrcType = SrcType->castAs<ComplexType>()->getElementType();
    400   DestType = DestType->castAs<ComplexType>()->getElementType();
    401 
    402   // C99 6.3.1.6: When a value of complex type is converted to another
    403   // complex type, both the real and imaginary parts follow the conversion
    404   // rules for the corresponding real types.
    405   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType);
    406   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType);
    407   return Val;
    408 }
    409 
    410 ComplexPairTy ComplexExprEmitter::EmitScalarToComplexCast(llvm::Value *Val,
    411                                                           QualType SrcType,
    412                                                           QualType DestType) {
    413   // Convert the input element to the element type of the complex.
    414   DestType = DestType->castAs<ComplexType>()->getElementType();
    415   Val = CGF.EmitScalarConversion(Val, SrcType, DestType);
    416 
    417   // Return (realval, 0).
    418   return ComplexPairTy(Val, llvm::Constant::getNullValue(Val->getType()));
    419 }
    420 
    421 ComplexPairTy ComplexExprEmitter::EmitCast(CastKind CK, Expr *Op,
    422                                            QualType DestTy) {
    423   switch (CK) {
    424   case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!");
    425 
    426   // Atomic to non-atomic casts may be more than a no-op for some platforms and
    427   // for some types.
    428   case CK_AtomicToNonAtomic:
    429   case CK_NonAtomicToAtomic:
    430   case CK_NoOp:
    431   case CK_LValueToRValue:
    432   case CK_UserDefinedConversion:
    433     return Visit(Op);
    434 
    435   case CK_LValueBitCast: {
    436     LValue origLV = CGF.EmitLValue(Op);
    437     llvm::Value *V = origLV.getAddress();
    438     V = Builder.CreateBitCast(V,
    439                     CGF.ConvertType(CGF.getContext().getPointerType(DestTy)));
    440     return EmitLoadOfLValue(CGF.MakeAddrLValue(V, DestTy,
    441                                                origLV.getAlignment()),
    442                             Op->getExprLoc());
    443   }
    444 
    445   case CK_BitCast:
    446   case CK_BaseToDerived:
    447   case CK_DerivedToBase:
    448   case CK_UncheckedDerivedToBase:
    449   case CK_Dynamic:
    450   case CK_ToUnion:
    451   case CK_ArrayToPointerDecay:
    452   case CK_FunctionToPointerDecay:
    453   case CK_NullToPointer:
    454   case CK_NullToMemberPointer:
    455   case CK_BaseToDerivedMemberPointer:
    456   case CK_DerivedToBaseMemberPointer:
    457   case CK_MemberPointerToBoolean:
    458   case CK_ReinterpretMemberPointer:
    459   case CK_ConstructorConversion:
    460   case CK_IntegralToPointer:
    461   case CK_PointerToIntegral:
    462   case CK_PointerToBoolean:
    463   case CK_ToVoid:
    464   case CK_VectorSplat:
    465   case CK_IntegralCast:
    466   case CK_IntegralToBoolean:
    467   case CK_IntegralToFloating:
    468   case CK_FloatingToIntegral:
    469   case CK_FloatingToBoolean:
    470   case CK_FloatingCast:
    471   case CK_CPointerToObjCPointerCast:
    472   case CK_BlockPointerToObjCPointerCast:
    473   case CK_AnyPointerToBlockPointerCast:
    474   case CK_ObjCObjectLValueCast:
    475   case CK_FloatingComplexToReal:
    476   case CK_FloatingComplexToBoolean:
    477   case CK_IntegralComplexToReal:
    478   case CK_IntegralComplexToBoolean:
    479   case CK_ARCProduceObject:
    480   case CK_ARCConsumeObject:
    481   case CK_ARCReclaimReturnedObject:
    482   case CK_ARCExtendBlockObject:
    483   case CK_CopyAndAutoreleaseBlockObject:
    484   case CK_BuiltinFnToFnPtr:
    485   case CK_ZeroToOCLEvent:
    486   case CK_AddressSpaceConversion:
    487     llvm_unreachable("invalid cast kind for complex value");
    488 
    489   case CK_FloatingRealToComplex:
    490   case CK_IntegralRealToComplex:
    491     return EmitScalarToComplexCast(CGF.EmitScalarExpr(Op),
    492                                    Op->getType(), DestTy);
    493 
    494   case CK_FloatingComplexCast:
    495   case CK_FloatingComplexToIntegralComplex:
    496   case CK_IntegralComplexCast:
    497   case CK_IntegralComplexToFloatingComplex:
    498     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
    499   }
    500 
    501   llvm_unreachable("unknown cast resulting in complex value");
    502 }
    503 
    504 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
    505   TestAndClearIgnoreReal();
    506   TestAndClearIgnoreImag();
    507   ComplexPairTy Op = Visit(E->getSubExpr());
    508 
    509   llvm::Value *ResR, *ResI;
    510   if (Op.first->getType()->isFloatingPointTy()) {
    511     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
    512     ResI = Builder.CreateFNeg(Op.second, "neg.i");
    513   } else {
    514     ResR = Builder.CreateNeg(Op.first,  "neg.r");
    515     ResI = Builder.CreateNeg(Op.second, "neg.i");
    516   }
    517   return ComplexPairTy(ResR, ResI);
    518 }
    519 
    520 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
    521   TestAndClearIgnoreReal();
    522   TestAndClearIgnoreImag();
    523   // ~(a+ib) = a + i*-b
    524   ComplexPairTy Op = Visit(E->getSubExpr());
    525   llvm::Value *ResI;
    526   if (Op.second->getType()->isFloatingPointTy())
    527     ResI = Builder.CreateFNeg(Op.second, "conj.i");
    528   else
    529     ResI = Builder.CreateNeg(Op.second, "conj.i");
    530 
    531   return ComplexPairTy(Op.first, ResI);
    532 }
    533 
    534 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
    535   llvm::Value *ResR, *ResI;
    536 
    537   if (Op.LHS.first->getType()->isFloatingPointTy()) {
    538     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
    539     if (Op.LHS.second && Op.RHS.second)
    540       ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
    541     else
    542       ResI = Op.LHS.second ? Op.LHS.second : Op.RHS.second;
    543     assert(ResI && "Only one operand may be real!");
    544   } else {
    545     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
    546     assert(Op.LHS.second && Op.RHS.second &&
    547            "Both operands of integer complex operators must be complex!");
    548     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
    549   }
    550   return ComplexPairTy(ResR, ResI);
    551 }
    552 
    553 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
    554   llvm::Value *ResR, *ResI;
    555   if (Op.LHS.first->getType()->isFloatingPointTy()) {
    556     ResR = Builder.CreateFSub(Op.LHS.first, Op.RHS.first, "sub.r");
    557     if (Op.LHS.second && Op.RHS.second)
    558       ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
    559     else
    560       ResI = Op.LHS.second ? Op.LHS.second
    561                            : Builder.CreateFNeg(Op.RHS.second, "sub.i");
    562     assert(ResI && "Only one operand may be real!");
    563   } else {
    564     ResR = Builder.CreateSub(Op.LHS.first, Op.RHS.first, "sub.r");
    565     assert(Op.LHS.second && Op.RHS.second &&
    566            "Both operands of integer complex operators must be complex!");
    567     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
    568   }
    569   return ComplexPairTy(ResR, ResI);
    570 }
    571 
    572 /// \brief Emit a libcall for a binary operation on complex types.
    573 ComplexPairTy ComplexExprEmitter::EmitComplexBinOpLibCall(StringRef LibCallName,
    574                                                           const BinOpInfo &Op) {
    575   CallArgList Args;
    576   Args.add(RValue::get(Op.LHS.first),
    577            Op.Ty->castAs<ComplexType>()->getElementType());
    578   Args.add(RValue::get(Op.LHS.second),
    579            Op.Ty->castAs<ComplexType>()->getElementType());
    580   Args.add(RValue::get(Op.RHS.first),
    581            Op.Ty->castAs<ComplexType>()->getElementType());
    582   Args.add(RValue::get(Op.RHS.second),
    583            Op.Ty->castAs<ComplexType>()->getElementType());
    584 
    585   // We *must* use the full CG function call building logic here because the
    586   // complex type has special ABI handling. We also should not forget about
    587   // special calling convention which may be used for compiler builtins.
    588   const CGFunctionInfo &FuncInfo =
    589     CGF.CGM.getTypes().arrangeFreeFunctionCall(
    590       Op.Ty, Args, FunctionType::ExtInfo(/* No CC here - will be added later */),
    591       RequiredArgs::All);
    592   llvm::FunctionType *FTy = CGF.CGM.getTypes().GetFunctionType(FuncInfo);
    593   llvm::Constant *Func = CGF.CGM.CreateBuiltinFunction(FTy, LibCallName);
    594   llvm::Instruction *Call;
    595 
    596   RValue Res = CGF.EmitCall(FuncInfo, Func, ReturnValueSlot(), Args,
    597                             nullptr, &Call);
    598   cast<llvm::CallInst>(Call)->setCallingConv(CGF.CGM.getBuiltinCC());
    599   cast<llvm::CallInst>(Call)->setDoesNotThrow();
    600 
    601   return Res.getComplexVal();
    602 }
    603 
    604 /// \brief Lookup the libcall name for a given floating point type complex
    605 /// multiply.
    606 static StringRef getComplexMultiplyLibCallName(llvm::Type *Ty) {
    607   switch (Ty->getTypeID()) {
    608   default:
    609     llvm_unreachable("Unsupported floating point type!");
    610   case llvm::Type::HalfTyID:
    611     return "__mulhc3";
    612   case llvm::Type::FloatTyID:
    613     return "__mulsc3";
    614   case llvm::Type::DoubleTyID:
    615     return "__muldc3";
    616   case llvm::Type::PPC_FP128TyID:
    617     return "__multc3";
    618   case llvm::Type::X86_FP80TyID:
    619     return "__mulxc3";
    620   case llvm::Type::FP128TyID:
    621     return "__multc3";
    622   }
    623 }
    624 
    625 // See C11 Annex G.5.1 for the semantics of multiplicative operators on complex
    626 // typed values.
    627 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
    628   using llvm::Value;
    629   Value *ResR, *ResI;
    630   llvm::MDBuilder MDHelper(CGF.getLLVMContext());
    631 
    632   if (Op.LHS.first->getType()->isFloatingPointTy()) {
    633     // The general formulation is:
    634     // (a + ib) * (c + id) = (a * c - b * d) + i(a * d + b * c)
    635     //
    636     // But we can fold away components which would be zero due to a real
    637     // operand according to C11 Annex G.5.1p2.
    638     // FIXME: C11 also provides for imaginary types which would allow folding
    639     // still more of this within the type system.
    640 
    641     if (Op.LHS.second && Op.RHS.second) {
    642       // If both operands are complex, emit the core math directly, and then
    643       // test for NaNs. If we find NaNs in the result, we delegate to a libcall
    644       // to carefully re-compute the correct infinity representation if
    645       // possible. The expectation is that the presence of NaNs here is
    646       // *extremely* rare, and so the cost of the libcall is almost irrelevant.
    647       // This is good, because the libcall re-computes the core multiplication
    648       // exactly the same as we do here and re-tests for NaNs in order to be
    649       // a generic complex*complex libcall.
    650 
    651       // First compute the four products.
    652       Value *AC = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul_ac");
    653       Value *BD = Builder.CreateFMul(Op.LHS.second, Op.RHS.second, "mul_bd");
    654       Value *AD = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul_ad");
    655       Value *BC = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul_bc");
    656 
    657       // The real part is the difference of the first two, the imaginary part is
    658       // the sum of the second.
    659       ResR = Builder.CreateFSub(AC, BD, "mul_r");
    660       ResI = Builder.CreateFAdd(AD, BC, "mul_i");
    661 
    662       // Emit the test for the real part becoming NaN and create a branch to
    663       // handle it. We test for NaN by comparing the number to itself.
    664       Value *IsRNaN = Builder.CreateFCmpUNO(ResR, ResR, "isnan_cmp");
    665       llvm::BasicBlock *ContBB = CGF.createBasicBlock("complex_mul_cont");
    666       llvm::BasicBlock *INaNBB = CGF.createBasicBlock("complex_mul_imag_nan");
    667       llvm::Instruction *Branch = Builder.CreateCondBr(IsRNaN, INaNBB, ContBB);
    668       llvm::BasicBlock *OrigBB = Branch->getParent();
    669 
    670       // Give hint that we very much don't expect to see NaNs.
    671       // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
    672       llvm::MDNode *BrWeight = MDHelper.createBranchWeights(1, (1U << 20) - 1);
    673       Branch->setMetadata(llvm::LLVMContext::MD_prof, BrWeight);
    674 
    675       // Now test the imaginary part and create its branch.
    676       CGF.EmitBlock(INaNBB);
    677       Value *IsINaN = Builder.CreateFCmpUNO(ResI, ResI, "isnan_cmp");
    678       llvm::BasicBlock *LibCallBB = CGF.createBasicBlock("complex_mul_libcall");
    679       Branch = Builder.CreateCondBr(IsINaN, LibCallBB, ContBB);
    680       Branch->setMetadata(llvm::LLVMContext::MD_prof, BrWeight);
    681 
    682       // Now emit the libcall on this slowest of the slow paths.
    683       CGF.EmitBlock(LibCallBB);
    684       Value *LibCallR, *LibCallI;
    685       std::tie(LibCallR, LibCallI) = EmitComplexBinOpLibCall(
    686           getComplexMultiplyLibCallName(Op.LHS.first->getType()), Op);
    687       Builder.CreateBr(ContBB);
    688 
    689       // Finally continue execution by phi-ing together the different
    690       // computation paths.
    691       CGF.EmitBlock(ContBB);
    692       llvm::PHINode *RealPHI = Builder.CreatePHI(ResR->getType(), 3, "real_mul_phi");
    693       RealPHI->addIncoming(ResR, OrigBB);
    694       RealPHI->addIncoming(ResR, INaNBB);
    695       RealPHI->addIncoming(LibCallR, LibCallBB);
    696       llvm::PHINode *ImagPHI = Builder.CreatePHI(ResI->getType(), 3, "imag_mul_phi");
    697       ImagPHI->addIncoming(ResI, OrigBB);
    698       ImagPHI->addIncoming(ResI, INaNBB);
    699       ImagPHI->addIncoming(LibCallI, LibCallBB);
    700       return ComplexPairTy(RealPHI, ImagPHI);
    701     }
    702     assert((Op.LHS.second || Op.RHS.second) &&
    703            "At least one operand must be complex!");
    704 
    705     // If either of the operands is a real rather than a complex, the
    706     // imaginary component is ignored when computing the real component of the
    707     // result.
    708     ResR = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
    709 
    710     ResI = Op.LHS.second
    711                ? Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il")
    712                : Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
    713   } else {
    714     assert(Op.LHS.second && Op.RHS.second &&
    715            "Both operands of integer complex operators must be complex!");
    716     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
    717     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second, "mul.rr");
    718     ResR = Builder.CreateSub(ResRl, ResRr, "mul.r");
    719 
    720     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
    721     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
    722     ResI = Builder.CreateAdd(ResIl, ResIr, "mul.i");
    723   }
    724   return ComplexPairTy(ResR, ResI);
    725 }
    726 
    727 // See C11 Annex G.5.1 for the semantics of multiplicative operators on complex
    728 // typed values.
    729 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
    730   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
    731   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
    732 
    733 
    734   llvm::Value *DSTr, *DSTi;
    735   if (LHSr->getType()->isFloatingPointTy()) {
    736     // If we have a complex operand on the RHS, we delegate to a libcall to
    737     // handle all of the complexities and minimize underflow/overflow cases.
    738     //
    739     // FIXME: We would be able to avoid the libcall in many places if we
    740     // supported imaginary types in addition to complex types.
    741     if (RHSi) {
    742       BinOpInfo LibCallOp = Op;
    743       // If LHS was a real, supply a null imaginary part.
    744       if (!LHSi)
    745         LibCallOp.LHS.second = llvm::Constant::getNullValue(LHSr->getType());
    746 
    747       StringRef LibCallName;
    748       switch (LHSr->getType()->getTypeID()) {
    749       default:
    750         llvm_unreachable("Unsupported floating point type!");
    751       case llvm::Type::HalfTyID:
    752         return EmitComplexBinOpLibCall("__divhc3", LibCallOp);
    753       case llvm::Type::FloatTyID:
    754         return EmitComplexBinOpLibCall("__divsc3", LibCallOp);
    755       case llvm::Type::DoubleTyID:
    756         return EmitComplexBinOpLibCall("__divdc3", LibCallOp);
    757       case llvm::Type::PPC_FP128TyID:
    758         return EmitComplexBinOpLibCall("__divtc3", LibCallOp);
    759       case llvm::Type::X86_FP80TyID:
    760         return EmitComplexBinOpLibCall("__divxc3", LibCallOp);
    761       case llvm::Type::FP128TyID:
    762         return EmitComplexBinOpLibCall("__divtc3", LibCallOp);
    763       }
    764     }
    765     assert(LHSi && "Can have at most one non-complex operand!");
    766 
    767     DSTr = Builder.CreateFDiv(LHSr, RHSr);
    768     DSTi = Builder.CreateFDiv(LHSi, RHSr);
    769   } else {
    770     assert(Op.LHS.second && Op.RHS.second &&
    771            "Both operands of integer complex operators must be complex!");
    772     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
    773     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr); // a*c
    774     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi); // b*d
    775     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2); // ac+bd
    776 
    777     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr); // c*c
    778     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi); // d*d
    779     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5); // cc+dd
    780 
    781     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr); // b*c
    782     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi); // a*d
    783     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8); // bc-ad
    784 
    785     if (Op.Ty->castAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
    786       DSTr = Builder.CreateUDiv(Tmp3, Tmp6);
    787       DSTi = Builder.CreateUDiv(Tmp9, Tmp6);
    788     } else {
    789       DSTr = Builder.CreateSDiv(Tmp3, Tmp6);
    790       DSTi = Builder.CreateSDiv(Tmp9, Tmp6);
    791     }
    792   }
    793 
    794   return ComplexPairTy(DSTr, DSTi);
    795 }
    796 
    797 ComplexExprEmitter::BinOpInfo
    798 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
    799   TestAndClearIgnoreReal();
    800   TestAndClearIgnoreImag();
    801   BinOpInfo Ops;
    802   if (E->getLHS()->getType()->isRealFloatingType())
    803     Ops.LHS = ComplexPairTy(CGF.EmitScalarExpr(E->getLHS()), nullptr);
    804   else
    805     Ops.LHS = Visit(E->getLHS());
    806   if (E->getRHS()->getType()->isRealFloatingType())
    807     Ops.RHS = ComplexPairTy(CGF.EmitScalarExpr(E->getRHS()), nullptr);
    808   else
    809     Ops.RHS = Visit(E->getRHS());
    810 
    811   Ops.Ty = E->getType();
    812   return Ops;
    813 }
    814 
    815 
    816 LValue ComplexExprEmitter::
    817 EmitCompoundAssignLValue(const CompoundAssignOperator *E,
    818           ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&),
    819                          RValue &Val) {
    820   TestAndClearIgnoreReal();
    821   TestAndClearIgnoreImag();
    822   QualType LHSTy = E->getLHS()->getType();
    823   if (const AtomicType *AT = LHSTy->getAs<AtomicType>())
    824     LHSTy = AT->getValueType();
    825 
    826   BinOpInfo OpInfo;
    827 
    828   // Load the RHS and LHS operands.
    829   // __block variables need to have the rhs evaluated first, plus this should
    830   // improve codegen a little.
    831   OpInfo.Ty = E->getComputationResultType();
    832   QualType ComplexElementTy = cast<ComplexType>(OpInfo.Ty)->getElementType();
    833 
    834   // The RHS should have been converted to the computation type.
    835   if (E->getRHS()->getType()->isRealFloatingType()) {
    836     assert(
    837         CGF.getContext()
    838             .hasSameUnqualifiedType(ComplexElementTy, E->getRHS()->getType()));
    839     OpInfo.RHS = ComplexPairTy(CGF.EmitScalarExpr(E->getRHS()), nullptr);
    840   } else {
    841     assert(CGF.getContext()
    842                .hasSameUnqualifiedType(OpInfo.Ty, E->getRHS()->getType()));
    843     OpInfo.RHS = Visit(E->getRHS());
    844   }
    845 
    846   LValue LHS = CGF.EmitLValue(E->getLHS());
    847 
    848   // Load from the l-value and convert it.
    849   if (LHSTy->isAnyComplexType()) {
    850     ComplexPairTy LHSVal = EmitLoadOfLValue(LHS, E->getExprLoc());
    851     OpInfo.LHS = EmitComplexToComplexCast(LHSVal, LHSTy, OpInfo.Ty);
    852   } else {
    853     llvm::Value *LHSVal = CGF.EmitLoadOfScalar(LHS, E->getExprLoc());
    854     // For floating point real operands we can directly pass the scalar form
    855     // to the binary operator emission and potentially get more efficient code.
    856     if (LHSTy->isRealFloatingType()) {
    857       if (!CGF.getContext().hasSameUnqualifiedType(ComplexElementTy, LHSTy))
    858         LHSVal = CGF.EmitScalarConversion(LHSVal, LHSTy, ComplexElementTy);
    859       OpInfo.LHS = ComplexPairTy(LHSVal, nullptr);
    860     } else {
    861       OpInfo.LHS = EmitScalarToComplexCast(LHSVal, LHSTy, OpInfo.Ty);
    862     }
    863   }
    864 
    865   // Expand the binary operator.
    866   ComplexPairTy Result = (this->*Func)(OpInfo);
    867 
    868   // Truncate the result and store it into the LHS lvalue.
    869   if (LHSTy->isAnyComplexType()) {
    870     ComplexPairTy ResVal = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
    871     EmitStoreOfComplex(ResVal, LHS, /*isInit*/ false);
    872     Val = RValue::getComplex(ResVal);
    873   } else {
    874     llvm::Value *ResVal =
    875         CGF.EmitComplexToScalarConversion(Result, OpInfo.Ty, LHSTy);
    876     CGF.EmitStoreOfScalar(ResVal, LHS, /*isInit*/ false);
    877     Val = RValue::get(ResVal);
    878   }
    879 
    880   return LHS;
    881 }
    882 
    883 // Compound assignments.
    884 ComplexPairTy ComplexExprEmitter::
    885 EmitCompoundAssign(const CompoundAssignOperator *E,
    886                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
    887   RValue Val;
    888   LValue LV = EmitCompoundAssignLValue(E, Func, Val);
    889 
    890   // The result of an assignment in C is the assigned r-value.
    891   if (!CGF.getLangOpts().CPlusPlus)
    892     return Val.getComplexVal();
    893 
    894   // If the lvalue is non-volatile, return the computed value of the assignment.
    895   if (!LV.isVolatileQualified())
    896     return Val.getComplexVal();
    897 
    898   return EmitLoadOfLValue(LV, E->getExprLoc());
    899 }
    900 
    901 LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
    902                                                ComplexPairTy &Val) {
    903   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
    904                                                  E->getRHS()->getType()) &&
    905          "Invalid assignment");
    906   TestAndClearIgnoreReal();
    907   TestAndClearIgnoreImag();
    908 
    909   // Emit the RHS.  __block variables need the RHS evaluated first.
    910   Val = Visit(E->getRHS());
    911 
    912   // Compute the address to store into.
    913   LValue LHS = CGF.EmitLValue(E->getLHS());
    914 
    915   // Store the result value into the LHS lvalue.
    916   EmitStoreOfComplex(Val, LHS, /*isInit*/ false);
    917 
    918   return LHS;
    919 }
    920 
    921 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
    922   ComplexPairTy Val;
    923   LValue LV = EmitBinAssignLValue(E, Val);
    924 
    925   // The result of an assignment in C is the assigned r-value.
    926   if (!CGF.getLangOpts().CPlusPlus)
    927     return Val;
    928 
    929   // If the lvalue is non-volatile, return the computed value of the assignment.
    930   if (!LV.isVolatileQualified())
    931     return Val;
    932 
    933   return EmitLoadOfLValue(LV, E->getExprLoc());
    934 }
    935 
    936 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
    937   CGF.EmitIgnoredExpr(E->getLHS());
    938   return Visit(E->getRHS());
    939 }
    940 
    941 ComplexPairTy ComplexExprEmitter::
    942 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
    943   TestAndClearIgnoreReal();
    944   TestAndClearIgnoreImag();
    945   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
    946   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
    947   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
    948 
    949   // Bind the common expression if necessary.
    950   CodeGenFunction::OpaqueValueMapping binding(CGF, E);
    951 
    952   RegionCounter Cnt = CGF.getPGORegionCounter(E);
    953   CodeGenFunction::ConditionalEvaluation eval(CGF);
    954   CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock, Cnt.getCount());
    955 
    956   eval.begin(CGF);
    957   CGF.EmitBlock(LHSBlock);
    958   Cnt.beginRegion(Builder);
    959   ComplexPairTy LHS = Visit(E->getTrueExpr());
    960   LHSBlock = Builder.GetInsertBlock();
    961   CGF.EmitBranch(ContBlock);
    962   eval.end(CGF);
    963 
    964   eval.begin(CGF);
    965   CGF.EmitBlock(RHSBlock);
    966   ComplexPairTy RHS = Visit(E->getFalseExpr());
    967   RHSBlock = Builder.GetInsertBlock();
    968   CGF.EmitBlock(ContBlock);
    969   eval.end(CGF);
    970 
    971   // Create a PHI node for the real part.
    972   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.r");
    973   RealPN->addIncoming(LHS.first, LHSBlock);
    974   RealPN->addIncoming(RHS.first, RHSBlock);
    975 
    976   // Create a PHI node for the imaginary part.
    977   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.i");
    978   ImagPN->addIncoming(LHS.second, LHSBlock);
    979   ImagPN->addIncoming(RHS.second, RHSBlock);
    980 
    981   return ComplexPairTy(RealPN, ImagPN);
    982 }
    983 
    984 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
    985   return Visit(E->getChosenSubExpr());
    986 }
    987 
    988 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
    989     bool Ignore = TestAndClearIgnoreReal();
    990     (void)Ignore;
    991     assert (Ignore == false && "init list ignored");
    992     Ignore = TestAndClearIgnoreImag();
    993     (void)Ignore;
    994     assert (Ignore == false && "init list ignored");
    995 
    996   if (E->getNumInits() == 2) {
    997     llvm::Value *Real = CGF.EmitScalarExpr(E->getInit(0));
    998     llvm::Value *Imag = CGF.EmitScalarExpr(E->getInit(1));
    999     return ComplexPairTy(Real, Imag);
   1000   } else if (E->getNumInits() == 1) {
   1001     return Visit(E->getInit(0));
   1002   }
   1003 
   1004   // Empty init list intializes to null
   1005   assert(E->getNumInits() == 0 && "Unexpected number of inits");
   1006   QualType Ty = E->getType()->castAs<ComplexType>()->getElementType();
   1007   llvm::Type* LTy = CGF.ConvertType(Ty);
   1008   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
   1009   return ComplexPairTy(zeroConstant, zeroConstant);
   1010 }
   1011 
   1012 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
   1013   llvm::Value *ArgValue = CGF.EmitVAListRef(E->getSubExpr());
   1014   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, E->getType());
   1015 
   1016   if (!ArgPtr) {
   1017     CGF.ErrorUnsupported(E, "complex va_arg expression");
   1018     llvm::Type *EltTy =
   1019       CGF.ConvertType(E->getType()->castAs<ComplexType>()->getElementType());
   1020     llvm::Value *U = llvm::UndefValue::get(EltTy);
   1021     return ComplexPairTy(U, U);
   1022   }
   1023 
   1024   return EmitLoadOfLValue(CGF.MakeNaturalAlignAddrLValue(ArgPtr, E->getType()),
   1025                           E->getExprLoc());
   1026 }
   1027 
   1028 //===----------------------------------------------------------------------===//
   1029 //                         Entry Point into this File
   1030 //===----------------------------------------------------------------------===//
   1031 
   1032 /// EmitComplexExpr - Emit the computation of the specified expression of
   1033 /// complex type, ignoring the result.
   1034 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
   1035                                                bool IgnoreImag) {
   1036   assert(E && getComplexType(E->getType()) &&
   1037          "Invalid complex expression to emit");
   1038 
   1039   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag)
   1040       .Visit(const_cast<Expr *>(E));
   1041 }
   1042 
   1043 void CodeGenFunction::EmitComplexExprIntoLValue(const Expr *E, LValue dest,
   1044                                                 bool isInit) {
   1045   assert(E && getComplexType(E->getType()) &&
   1046          "Invalid complex expression to emit");
   1047   ComplexExprEmitter Emitter(*this);
   1048   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
   1049   Emitter.EmitStoreOfComplex(Val, dest, isInit);
   1050 }
   1051 
   1052 /// EmitStoreOfComplex - Store a complex number into the specified l-value.
   1053 void CodeGenFunction::EmitStoreOfComplex(ComplexPairTy V, LValue dest,
   1054                                          bool isInit) {
   1055   ComplexExprEmitter(*this).EmitStoreOfComplex(V, dest, isInit);
   1056 }
   1057 
   1058 /// EmitLoadOfComplex - Load a complex number from the specified address.
   1059 ComplexPairTy CodeGenFunction::EmitLoadOfComplex(LValue src,
   1060                                                  SourceLocation loc) {
   1061   return ComplexExprEmitter(*this).EmitLoadOfLValue(src, loc);
   1062 }
   1063 
   1064 LValue CodeGenFunction::EmitComplexAssignmentLValue(const BinaryOperator *E) {
   1065   assert(E->getOpcode() == BO_Assign);
   1066   ComplexPairTy Val; // ignored
   1067   return ComplexExprEmitter(*this).EmitBinAssignLValue(E, Val);
   1068 }
   1069 
   1070 typedef ComplexPairTy (ComplexExprEmitter::*CompoundFunc)(
   1071     const ComplexExprEmitter::BinOpInfo &);
   1072 
   1073 static CompoundFunc getComplexOp(BinaryOperatorKind Op) {
   1074   switch (Op) {
   1075   case BO_MulAssign: return &ComplexExprEmitter::EmitBinMul;
   1076   case BO_DivAssign: return &ComplexExprEmitter::EmitBinDiv;
   1077   case BO_SubAssign: return &ComplexExprEmitter::EmitBinSub;
   1078   case BO_AddAssign: return &ComplexExprEmitter::EmitBinAdd;
   1079   default:
   1080     llvm_unreachable("unexpected complex compound assignment");
   1081   }
   1082 }
   1083 
   1084 LValue CodeGenFunction::
   1085 EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E) {
   1086   CompoundFunc Op = getComplexOp(E->getOpcode());
   1087   RValue Val;
   1088   return ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
   1089 }
   1090 
   1091 LValue CodeGenFunction::
   1092 EmitScalarCompoundAssignWithComplex(const CompoundAssignOperator *E,
   1093                                     llvm::Value *&Result) {
   1094   CompoundFunc Op = getComplexOp(E->getOpcode());
   1095   RValue Val;
   1096   LValue Ret = ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
   1097   Result = Val.getScalarVal();
   1098   return Ret;
   1099 }
   1100