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   /// Emit a cast from complex value Val to DestType.
87   ComplexPairTy EmitComplexToComplexCast(ComplexPairTy Val, QualType SrcType,
88                                          QualType DestType, SourceLocation Loc);
89   /// Emit a cast from scalar value Val to DestType.
90   ComplexPairTy EmitScalarToComplexCast(llvm::Value *Val, QualType SrcType,
91                                         QualType DestType, SourceLocation Loc);
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 /// Emit a cast from complex value Val to DestType.
395 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
396                                                            QualType SrcType,
397                                                            QualType DestType,
398                                                            SourceLocation Loc) {
399   // Get the src/dest element type.
400   SrcType = SrcType->castAs<ComplexType>()->getElementType();
401   DestType = DestType->castAs<ComplexType>()->getElementType();
402 
403   // C99 6.3.1.6: When a value of complex type is converted to another
404   // complex type, both the real and imaginary parts follow the conversion
405   // rules for the corresponding real types.
406   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType, Loc);
407   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType, Loc);
408   return Val;
409 }
410 
411 ComplexPairTy ComplexExprEmitter::EmitScalarToComplexCast(llvm::Value *Val,
412                                                           QualType SrcType,
413                                                           QualType DestType,
414                                                           SourceLocation Loc) {
415   // Convert the input element to the element type of the complex.
416   DestType = DestType->castAs<ComplexType>()->getElementType();
417   Val = CGF.EmitScalarConversion(Val, SrcType, DestType, Loc);
418 
419   // Return (realval, 0).
420   return ComplexPairTy(Val, llvm::Constant::getNullValue(Val->getType()));
421 }
422 
423 ComplexPairTy ComplexExprEmitter::EmitCast(CastKind CK, Expr *Op,
424                                            QualType DestTy) {
425   switch (CK) {
426   case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!");
427 
428   // Atomic to non-atomic casts may be more than a no-op for some platforms and
429   // for some types.
430   case CK_AtomicToNonAtomic:
431   case CK_NonAtomicToAtomic:
432   case CK_NoOp:
433   case CK_LValueToRValue:
434   case CK_UserDefinedConversion:
435     return Visit(Op);
436 
437   case CK_LValueBitCast: {
438     LValue origLV = CGF.EmitLValue(Op);
439     llvm::Value *V = origLV.getAddress();
440     V = Builder.CreateBitCast(V,
441                     CGF.ConvertType(CGF.getContext().getPointerType(DestTy)));
442     return EmitLoadOfLValue(CGF.MakeAddrLValue(V, DestTy,
443                                                origLV.getAlignment()),
444                             Op->getExprLoc());
445   }
446 
447   case CK_BitCast:
448   case CK_BaseToDerived:
449   case CK_DerivedToBase:
450   case CK_UncheckedDerivedToBase:
451   case CK_Dynamic:
452   case CK_ToUnion:
453   case CK_ArrayToPointerDecay:
454   case CK_FunctionToPointerDecay:
455   case CK_NullToPointer:
456   case CK_NullToMemberPointer:
457   case CK_BaseToDerivedMemberPointer:
458   case CK_DerivedToBaseMemberPointer:
459   case CK_MemberPointerToBoolean:
460   case CK_ReinterpretMemberPointer:
461   case CK_ConstructorConversion:
462   case CK_IntegralToPointer:
463   case CK_PointerToIntegral:
464   case CK_PointerToBoolean:
465   case CK_ToVoid:
466   case CK_VectorSplat:
467   case CK_IntegralCast:
468   case CK_IntegralToBoolean:
469   case CK_IntegralToFloating:
470   case CK_FloatingToIntegral:
471   case CK_FloatingToBoolean:
472   case CK_FloatingCast:
473   case CK_CPointerToObjCPointerCast:
474   case CK_BlockPointerToObjCPointerCast:
475   case CK_AnyPointerToBlockPointerCast:
476   case CK_ObjCObjectLValueCast:
477   case CK_FloatingComplexToReal:
478   case CK_FloatingComplexToBoolean:
479   case CK_IntegralComplexToReal:
480   case CK_IntegralComplexToBoolean:
481   case CK_ARCProduceObject:
482   case CK_ARCConsumeObject:
483   case CK_ARCReclaimReturnedObject:
484   case CK_ARCExtendBlockObject:
485   case CK_CopyAndAutoreleaseBlockObject:
486   case CK_BuiltinFnToFnPtr:
487   case CK_ZeroToOCLEvent:
488   case CK_AddressSpaceConversion:
489     llvm_unreachable("invalid cast kind for complex value");
490 
491   case CK_FloatingRealToComplex:
492   case CK_IntegralRealToComplex:
493     return EmitScalarToComplexCast(CGF.EmitScalarExpr(Op), Op->getType(),
494                                    DestTy, Op->getExprLoc());
495 
496   case CK_FloatingComplexCast:
497   case CK_FloatingComplexToIntegralComplex:
498   case CK_IntegralComplexCast:
499   case CK_IntegralComplexToFloatingComplex:
500     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy,
501                                     Op->getExprLoc());
502   }
503 
504   llvm_unreachable("unknown cast resulting in complex value");
505 }
506 
507 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
508   TestAndClearIgnoreReal();
509   TestAndClearIgnoreImag();
510   ComplexPairTy Op = Visit(E->getSubExpr());
511 
512   llvm::Value *ResR, *ResI;
513   if (Op.first->getType()->isFloatingPointTy()) {
514     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
515     ResI = Builder.CreateFNeg(Op.second, "neg.i");
516   } else {
517     ResR = Builder.CreateNeg(Op.first,  "neg.r");
518     ResI = Builder.CreateNeg(Op.second, "neg.i");
519   }
520   return ComplexPairTy(ResR, ResI);
521 }
522 
523 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
524   TestAndClearIgnoreReal();
525   TestAndClearIgnoreImag();
526   // ~(a+ib) = a + i*-b
527   ComplexPairTy Op = Visit(E->getSubExpr());
528   llvm::Value *ResI;
529   if (Op.second->getType()->isFloatingPointTy())
530     ResI = Builder.CreateFNeg(Op.second, "conj.i");
531   else
532     ResI = Builder.CreateNeg(Op.second, "conj.i");
533 
534   return ComplexPairTy(Op.first, ResI);
535 }
536 
537 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
538   llvm::Value *ResR, *ResI;
539 
540   if (Op.LHS.first->getType()->isFloatingPointTy()) {
541     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
542     if (Op.LHS.second && Op.RHS.second)
543       ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
544     else
545       ResI = Op.LHS.second ? Op.LHS.second : Op.RHS.second;
546     assert(ResI && "Only one operand may be real!");
547   } else {
548     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
549     assert(Op.LHS.second && Op.RHS.second &&
550            "Both operands of integer complex operators must be complex!");
551     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
552   }
553   return ComplexPairTy(ResR, ResI);
554 }
555 
556 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
557   llvm::Value *ResR, *ResI;
558   if (Op.LHS.first->getType()->isFloatingPointTy()) {
559     ResR = Builder.CreateFSub(Op.LHS.first, Op.RHS.first, "sub.r");
560     if (Op.LHS.second && Op.RHS.second)
561       ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
562     else
563       ResI = Op.LHS.second ? Op.LHS.second
564                            : Builder.CreateFNeg(Op.RHS.second, "sub.i");
565     assert(ResI && "Only one operand may be real!");
566   } else {
567     ResR = Builder.CreateSub(Op.LHS.first, Op.RHS.first, "sub.r");
568     assert(Op.LHS.second && Op.RHS.second &&
569            "Both operands of integer complex operators must be complex!");
570     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
571   }
572   return ComplexPairTy(ResR, ResI);
573 }
574 
575 /// \brief Emit a libcall for a binary operation on complex types.
576 ComplexPairTy ComplexExprEmitter::EmitComplexBinOpLibCall(StringRef LibCallName,
577                                                           const BinOpInfo &Op) {
578   CallArgList Args;
579   Args.add(RValue::get(Op.LHS.first),
580            Op.Ty->castAs<ComplexType>()->getElementType());
581   Args.add(RValue::get(Op.LHS.second),
582            Op.Ty->castAs<ComplexType>()->getElementType());
583   Args.add(RValue::get(Op.RHS.first),
584            Op.Ty->castAs<ComplexType>()->getElementType());
585   Args.add(RValue::get(Op.RHS.second),
586            Op.Ty->castAs<ComplexType>()->getElementType());
587 
588   // We *must* use the full CG function call building logic here because the
589   // complex type has special ABI handling. We also should not forget about
590   // special calling convention which may be used for compiler builtins.
591   const CGFunctionInfo &FuncInfo =
592     CGF.CGM.getTypes().arrangeFreeFunctionCall(
593       Op.Ty, Args, FunctionType::ExtInfo(/* No CC here - will be added later */),
594       RequiredArgs::All);
595   llvm::FunctionType *FTy = CGF.CGM.getTypes().GetFunctionType(FuncInfo);
596   llvm::Constant *Func = CGF.CGM.CreateBuiltinFunction(FTy, LibCallName);
597   llvm::Instruction *Call;
598 
599   RValue Res = CGF.EmitCall(FuncInfo, Func, ReturnValueSlot(), Args,
600                             nullptr, &Call);
601   cast<llvm::CallInst>(Call)->setCallingConv(CGF.CGM.getBuiltinCC());
602   cast<llvm::CallInst>(Call)->setDoesNotThrow();
603 
604   return Res.getComplexVal();
605 }
606 
607 /// \brief Lookup the libcall name for a given floating point type complex
608 /// multiply.
609 static StringRef getComplexMultiplyLibCallName(llvm::Type *Ty) {
610   switch (Ty->getTypeID()) {
611   default:
612     llvm_unreachable("Unsupported floating point type!");
613   case llvm::Type::HalfTyID:
614     return "__mulhc3";
615   case llvm::Type::FloatTyID:
616     return "__mulsc3";
617   case llvm::Type::DoubleTyID:
618     return "__muldc3";
619   case llvm::Type::PPC_FP128TyID:
620     return "__multc3";
621   case llvm::Type::X86_FP80TyID:
622     return "__mulxc3";
623   case llvm::Type::FP128TyID:
624     return "__multc3";
625   }
626 }
627 
628 // See C11 Annex G.5.1 for the semantics of multiplicative operators on complex
629 // typed values.
630 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
631   using llvm::Value;
632   Value *ResR, *ResI;
633   llvm::MDBuilder MDHelper(CGF.getLLVMContext());
634 
635   if (Op.LHS.first->getType()->isFloatingPointTy()) {
636     // The general formulation is:
637     // (a + ib) * (c + id) = (a * c - b * d) + i(a * d + b * c)
638     //
639     // But we can fold away components which would be zero due to a real
640     // operand according to C11 Annex G.5.1p2.
641     // FIXME: C11 also provides for imaginary types which would allow folding
642     // still more of this within the type system.
643 
644     if (Op.LHS.second && Op.RHS.second) {
645       // If both operands are complex, emit the core math directly, and then
646       // test for NaNs. If we find NaNs in the result, we delegate to a libcall
647       // to carefully re-compute the correct infinity representation if
648       // possible. The expectation is that the presence of NaNs here is
649       // *extremely* rare, and so the cost of the libcall is almost irrelevant.
650       // This is good, because the libcall re-computes the core multiplication
651       // exactly the same as we do here and re-tests for NaNs in order to be
652       // a generic complex*complex libcall.
653 
654       // First compute the four products.
655       Value *AC = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul_ac");
656       Value *BD = Builder.CreateFMul(Op.LHS.second, Op.RHS.second, "mul_bd");
657       Value *AD = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul_ad");
658       Value *BC = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul_bc");
659 
660       // The real part is the difference of the first two, the imaginary part is
661       // the sum of the second.
662       ResR = Builder.CreateFSub(AC, BD, "mul_r");
663       ResI = Builder.CreateFAdd(AD, BC, "mul_i");
664 
665       // Emit the test for the real part becoming NaN and create a branch to
666       // handle it. We test for NaN by comparing the number to itself.
667       Value *IsRNaN = Builder.CreateFCmpUNO(ResR, ResR, "isnan_cmp");
668       llvm::BasicBlock *ContBB = CGF.createBasicBlock("complex_mul_cont");
669       llvm::BasicBlock *INaNBB = CGF.createBasicBlock("complex_mul_imag_nan");
670       llvm::Instruction *Branch = Builder.CreateCondBr(IsRNaN, INaNBB, ContBB);
671       llvm::BasicBlock *OrigBB = Branch->getParent();
672 
673       // Give hint that we very much don't expect to see NaNs.
674       // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
675       llvm::MDNode *BrWeight = MDHelper.createBranchWeights(1, (1U << 20) - 1);
676       Branch->setMetadata(llvm::LLVMContext::MD_prof, BrWeight);
677 
678       // Now test the imaginary part and create its branch.
679       CGF.EmitBlock(INaNBB);
680       Value *IsINaN = Builder.CreateFCmpUNO(ResI, ResI, "isnan_cmp");
681       llvm::BasicBlock *LibCallBB = CGF.createBasicBlock("complex_mul_libcall");
682       Branch = Builder.CreateCondBr(IsINaN, LibCallBB, ContBB);
683       Branch->setMetadata(llvm::LLVMContext::MD_prof, BrWeight);
684 
685       // Now emit the libcall on this slowest of the slow paths.
686       CGF.EmitBlock(LibCallBB);
687       Value *LibCallR, *LibCallI;
688       std::tie(LibCallR, LibCallI) = EmitComplexBinOpLibCall(
689           getComplexMultiplyLibCallName(Op.LHS.first->getType()), Op);
690       Builder.CreateBr(ContBB);
691 
692       // Finally continue execution by phi-ing together the different
693       // computation paths.
694       CGF.EmitBlock(ContBB);
695       llvm::PHINode *RealPHI = Builder.CreatePHI(ResR->getType(), 3, "real_mul_phi");
696       RealPHI->addIncoming(ResR, OrigBB);
697       RealPHI->addIncoming(ResR, INaNBB);
698       RealPHI->addIncoming(LibCallR, LibCallBB);
699       llvm::PHINode *ImagPHI = Builder.CreatePHI(ResI->getType(), 3, "imag_mul_phi");
700       ImagPHI->addIncoming(ResI, OrigBB);
701       ImagPHI->addIncoming(ResI, INaNBB);
702       ImagPHI->addIncoming(LibCallI, LibCallBB);
703       return ComplexPairTy(RealPHI, ImagPHI);
704     }
705     assert((Op.LHS.second || Op.RHS.second) &&
706            "At least one operand must be complex!");
707 
708     // If either of the operands is a real rather than a complex, the
709     // imaginary component is ignored when computing the real component of the
710     // result.
711     ResR = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
712 
713     ResI = Op.LHS.second
714                ? Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il")
715                : Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
716   } else {
717     assert(Op.LHS.second && Op.RHS.second &&
718            "Both operands of integer complex operators must be complex!");
719     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
720     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second, "mul.rr");
721     ResR = Builder.CreateSub(ResRl, ResRr, "mul.r");
722 
723     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
724     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
725     ResI = Builder.CreateAdd(ResIl, ResIr, "mul.i");
726   }
727   return ComplexPairTy(ResR, ResI);
728 }
729 
730 // See C11 Annex G.5.1 for the semantics of multiplicative operators on complex
731 // typed values.
732 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
733   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
734   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
735 
736 
737   llvm::Value *DSTr, *DSTi;
738   if (LHSr->getType()->isFloatingPointTy()) {
739     // If we have a complex operand on the RHS, we delegate to a libcall to
740     // handle all of the complexities and minimize underflow/overflow cases.
741     //
742     // FIXME: We would be able to avoid the libcall in many places if we
743     // supported imaginary types in addition to complex types.
744     if (RHSi) {
745       BinOpInfo LibCallOp = Op;
746       // If LHS was a real, supply a null imaginary part.
747       if (!LHSi)
748         LibCallOp.LHS.second = llvm::Constant::getNullValue(LHSr->getType());
749 
750       StringRef LibCallName;
751       switch (LHSr->getType()->getTypeID()) {
752       default:
753         llvm_unreachable("Unsupported floating point type!");
754       case llvm::Type::HalfTyID:
755         return EmitComplexBinOpLibCall("__divhc3", LibCallOp);
756       case llvm::Type::FloatTyID:
757         return EmitComplexBinOpLibCall("__divsc3", LibCallOp);
758       case llvm::Type::DoubleTyID:
759         return EmitComplexBinOpLibCall("__divdc3", LibCallOp);
760       case llvm::Type::PPC_FP128TyID:
761         return EmitComplexBinOpLibCall("__divtc3", LibCallOp);
762       case llvm::Type::X86_FP80TyID:
763         return EmitComplexBinOpLibCall("__divxc3", LibCallOp);
764       case llvm::Type::FP128TyID:
765         return EmitComplexBinOpLibCall("__divtc3", LibCallOp);
766       }
767     }
768     assert(LHSi && "Can have at most one non-complex operand!");
769 
770     DSTr = Builder.CreateFDiv(LHSr, RHSr);
771     DSTi = Builder.CreateFDiv(LHSi, RHSr);
772   } else {
773     assert(Op.LHS.second && Op.RHS.second &&
774            "Both operands of integer complex operators must be complex!");
775     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
776     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr); // a*c
777     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi); // b*d
778     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2); // ac+bd
779 
780     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr); // c*c
781     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi); // d*d
782     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5); // cc+dd
783 
784     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr); // b*c
785     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi); // a*d
786     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8); // bc-ad
787 
788     if (Op.Ty->castAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
789       DSTr = Builder.CreateUDiv(Tmp3, Tmp6);
790       DSTi = Builder.CreateUDiv(Tmp9, Tmp6);
791     } else {
792       DSTr = Builder.CreateSDiv(Tmp3, Tmp6);
793       DSTi = Builder.CreateSDiv(Tmp9, Tmp6);
794     }
795   }
796 
797   return ComplexPairTy(DSTr, DSTi);
798 }
799 
800 ComplexExprEmitter::BinOpInfo
801 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
802   TestAndClearIgnoreReal();
803   TestAndClearIgnoreImag();
804   BinOpInfo Ops;
805   if (E->getLHS()->getType()->isRealFloatingType())
806     Ops.LHS = ComplexPairTy(CGF.EmitScalarExpr(E->getLHS()), nullptr);
807   else
808     Ops.LHS = Visit(E->getLHS());
809   if (E->getRHS()->getType()->isRealFloatingType())
810     Ops.RHS = ComplexPairTy(CGF.EmitScalarExpr(E->getRHS()), nullptr);
811   else
812     Ops.RHS = Visit(E->getRHS());
813 
814   Ops.Ty = E->getType();
815   return Ops;
816 }
817 
818 
819 LValue ComplexExprEmitter::
820 EmitCompoundAssignLValue(const CompoundAssignOperator *E,
821           ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&),
822                          RValue &Val) {
823   TestAndClearIgnoreReal();
824   TestAndClearIgnoreImag();
825   QualType LHSTy = E->getLHS()->getType();
826   if (const AtomicType *AT = LHSTy->getAs<AtomicType>())
827     LHSTy = AT->getValueType();
828 
829   BinOpInfo OpInfo;
830 
831   // Load the RHS and LHS operands.
832   // __block variables need to have the rhs evaluated first, plus this should
833   // improve codegen a little.
834   OpInfo.Ty = E->getComputationResultType();
835   QualType ComplexElementTy = cast<ComplexType>(OpInfo.Ty)->getElementType();
836 
837   // The RHS should have been converted to the computation type.
838   if (E->getRHS()->getType()->isRealFloatingType()) {
839     assert(
840         CGF.getContext()
841             .hasSameUnqualifiedType(ComplexElementTy, E->getRHS()->getType()));
842     OpInfo.RHS = ComplexPairTy(CGF.EmitScalarExpr(E->getRHS()), nullptr);
843   } else {
844     assert(CGF.getContext()
845                .hasSameUnqualifiedType(OpInfo.Ty, E->getRHS()->getType()));
846     OpInfo.RHS = Visit(E->getRHS());
847   }
848 
849   LValue LHS = CGF.EmitLValue(E->getLHS());
850 
851   // Load from the l-value and convert it.
852   SourceLocation Loc = E->getExprLoc();
853   if (LHSTy->isAnyComplexType()) {
854     ComplexPairTy LHSVal = EmitLoadOfLValue(LHS, Loc);
855     OpInfo.LHS = EmitComplexToComplexCast(LHSVal, LHSTy, OpInfo.Ty, Loc);
856   } else {
857     llvm::Value *LHSVal = CGF.EmitLoadOfScalar(LHS, Loc);
858     // For floating point real operands we can directly pass the scalar form
859     // to the binary operator emission and potentially get more efficient code.
860     if (LHSTy->isRealFloatingType()) {
861       if (!CGF.getContext().hasSameUnqualifiedType(ComplexElementTy, LHSTy))
862         LHSVal = CGF.EmitScalarConversion(LHSVal, LHSTy, ComplexElementTy, Loc);
863       OpInfo.LHS = ComplexPairTy(LHSVal, nullptr);
864     } else {
865       OpInfo.LHS = EmitScalarToComplexCast(LHSVal, LHSTy, OpInfo.Ty, Loc);
866     }
867   }
868 
869   // Expand the binary operator.
870   ComplexPairTy Result = (this->*Func)(OpInfo);
871 
872   // Truncate the result and store it into the LHS lvalue.
873   if (LHSTy->isAnyComplexType()) {
874     ComplexPairTy ResVal =
875         EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy, Loc);
876     EmitStoreOfComplex(ResVal, LHS, /*isInit*/ false);
877     Val = RValue::getComplex(ResVal);
878   } else {
879     llvm::Value *ResVal =
880         CGF.EmitComplexToScalarConversion(Result, OpInfo.Ty, LHSTy, Loc);
881     CGF.EmitStoreOfScalar(ResVal, LHS, /*isInit*/ false);
882     Val = RValue::get(ResVal);
883   }
884 
885   return LHS;
886 }
887 
888 // Compound assignments.
889 ComplexPairTy ComplexExprEmitter::
890 EmitCompoundAssign(const CompoundAssignOperator *E,
891                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
892   RValue Val;
893   LValue LV = EmitCompoundAssignLValue(E, Func, Val);
894 
895   // The result of an assignment in C is the assigned r-value.
896   if (!CGF.getLangOpts().CPlusPlus)
897     return Val.getComplexVal();
898 
899   // If the lvalue is non-volatile, return the computed value of the assignment.
900   if (!LV.isVolatileQualified())
901     return Val.getComplexVal();
902 
903   return EmitLoadOfLValue(LV, E->getExprLoc());
904 }
905 
906 LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
907                                                ComplexPairTy &Val) {
908   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
909                                                  E->getRHS()->getType()) &&
910          "Invalid assignment");
911   TestAndClearIgnoreReal();
912   TestAndClearIgnoreImag();
913 
914   // Emit the RHS.  __block variables need the RHS evaluated first.
915   Val = Visit(E->getRHS());
916 
917   // Compute the address to store into.
918   LValue LHS = CGF.EmitLValue(E->getLHS());
919 
920   // Store the result value into the LHS lvalue.
921   EmitStoreOfComplex(Val, LHS, /*isInit*/ false);
922 
923   return LHS;
924 }
925 
926 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
927   ComplexPairTy Val;
928   LValue LV = EmitBinAssignLValue(E, Val);
929 
930   // The result of an assignment in C is the assigned r-value.
931   if (!CGF.getLangOpts().CPlusPlus)
932     return Val;
933 
934   // If the lvalue is non-volatile, return the computed value of the assignment.
935   if (!LV.isVolatileQualified())
936     return Val;
937 
938   return EmitLoadOfLValue(LV, E->getExprLoc());
939 }
940 
941 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
942   CGF.EmitIgnoredExpr(E->getLHS());
943   return Visit(E->getRHS());
944 }
945 
946 ComplexPairTy ComplexExprEmitter::
947 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
948   TestAndClearIgnoreReal();
949   TestAndClearIgnoreImag();
950   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
951   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
952   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
953 
954   // Bind the common expression if necessary.
955   CodeGenFunction::OpaqueValueMapping binding(CGF, E);
956 
957 
958   CodeGenFunction::ConditionalEvaluation eval(CGF);
959   CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock,
960                            CGF.getProfileCount(E));
961 
962   eval.begin(CGF);
963   CGF.EmitBlock(LHSBlock);
964   CGF.incrementProfileCounter(E);
965   ComplexPairTy LHS = Visit(E->getTrueExpr());
966   LHSBlock = Builder.GetInsertBlock();
967   CGF.EmitBranch(ContBlock);
968   eval.end(CGF);
969 
970   eval.begin(CGF);
971   CGF.EmitBlock(RHSBlock);
972   ComplexPairTy RHS = Visit(E->getFalseExpr());
973   RHSBlock = Builder.GetInsertBlock();
974   CGF.EmitBlock(ContBlock);
975   eval.end(CGF);
976 
977   // Create a PHI node for the real part.
978   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.r");
979   RealPN->addIncoming(LHS.first, LHSBlock);
980   RealPN->addIncoming(RHS.first, RHSBlock);
981 
982   // Create a PHI node for the imaginary part.
983   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.i");
984   ImagPN->addIncoming(LHS.second, LHSBlock);
985   ImagPN->addIncoming(RHS.second, RHSBlock);
986 
987   return ComplexPairTy(RealPN, ImagPN);
988 }
989 
990 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
991   return Visit(E->getChosenSubExpr());
992 }
993 
994 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
995     bool Ignore = TestAndClearIgnoreReal();
996     (void)Ignore;
997     assert (Ignore == false && "init list ignored");
998     Ignore = TestAndClearIgnoreImag();
999     (void)Ignore;
1000     assert (Ignore == false && "init list ignored");
1001 
1002   if (E->getNumInits() == 2) {
1003     llvm::Value *Real = CGF.EmitScalarExpr(E->getInit(0));
1004     llvm::Value *Imag = CGF.EmitScalarExpr(E->getInit(1));
1005     return ComplexPairTy(Real, Imag);
1006   } else if (E->getNumInits() == 1) {
1007     return Visit(E->getInit(0));
1008   }
1009 
1010   // Empty init list intializes to null
1011   assert(E->getNumInits() == 0 && "Unexpected number of inits");
1012   QualType Ty = E->getType()->castAs<ComplexType>()->getElementType();
1013   llvm::Type* LTy = CGF.ConvertType(Ty);
1014   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
1015   return ComplexPairTy(zeroConstant, zeroConstant);
1016 }
1017 
1018 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
1019   llvm::Value *ArgValue = CGF.EmitVAListRef(E->getSubExpr());
1020   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, E->getType());
1021 
1022   if (!ArgPtr) {
1023     CGF.ErrorUnsupported(E, "complex va_arg expression");
1024     llvm::Type *EltTy =
1025       CGF.ConvertType(E->getType()->castAs<ComplexType>()->getElementType());
1026     llvm::Value *U = llvm::UndefValue::get(EltTy);
1027     return ComplexPairTy(U, U);
1028   }
1029 
1030   return EmitLoadOfLValue(CGF.MakeNaturalAlignAddrLValue(ArgPtr, E->getType()),
1031                           E->getExprLoc());
1032 }
1033 
1034 //===----------------------------------------------------------------------===//
1035 //                         Entry Point into this File
1036 //===----------------------------------------------------------------------===//
1037 
1038 /// EmitComplexExpr - Emit the computation of the specified expression of
1039 /// complex type, ignoring the result.
1040 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
1041                                                bool IgnoreImag) {
1042   assert(E && getComplexType(E->getType()) &&
1043          "Invalid complex expression to emit");
1044 
1045   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag)
1046       .Visit(const_cast<Expr *>(E));
1047 }
1048 
1049 void CodeGenFunction::EmitComplexExprIntoLValue(const Expr *E, LValue dest,
1050                                                 bool isInit) {
1051   assert(E && getComplexType(E->getType()) &&
1052          "Invalid complex expression to emit");
1053   ComplexExprEmitter Emitter(*this);
1054   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
1055   Emitter.EmitStoreOfComplex(Val, dest, isInit);
1056 }
1057 
1058 /// EmitStoreOfComplex - Store a complex number into the specified l-value.
1059 void CodeGenFunction::EmitStoreOfComplex(ComplexPairTy V, LValue dest,
1060                                          bool isInit) {
1061   ComplexExprEmitter(*this).EmitStoreOfComplex(V, dest, isInit);
1062 }
1063 
1064 /// EmitLoadOfComplex - Load a complex number from the specified address.
1065 ComplexPairTy CodeGenFunction::EmitLoadOfComplex(LValue src,
1066                                                  SourceLocation loc) {
1067   return ComplexExprEmitter(*this).EmitLoadOfLValue(src, loc);
1068 }
1069 
1070 LValue CodeGenFunction::EmitComplexAssignmentLValue(const BinaryOperator *E) {
1071   assert(E->getOpcode() == BO_Assign);
1072   ComplexPairTy Val; // ignored
1073   return ComplexExprEmitter(*this).EmitBinAssignLValue(E, Val);
1074 }
1075 
1076 typedef ComplexPairTy (ComplexExprEmitter::*CompoundFunc)(
1077     const ComplexExprEmitter::BinOpInfo &);
1078 
1079 static CompoundFunc getComplexOp(BinaryOperatorKind Op) {
1080   switch (Op) {
1081   case BO_MulAssign: return &ComplexExprEmitter::EmitBinMul;
1082   case BO_DivAssign: return &ComplexExprEmitter::EmitBinDiv;
1083   case BO_SubAssign: return &ComplexExprEmitter::EmitBinSub;
1084   case BO_AddAssign: return &ComplexExprEmitter::EmitBinAdd;
1085   default:
1086     llvm_unreachable("unexpected complex compound assignment");
1087   }
1088 }
1089 
1090 LValue CodeGenFunction::
1091 EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E) {
1092   CompoundFunc Op = getComplexOp(E->getOpcode());
1093   RValue Val;
1094   return ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
1095 }
1096 
1097 LValue CodeGenFunction::
1098 EmitScalarCompoundAssignWithComplex(const CompoundAssignOperator *E,
1099                                     llvm::Value *&Result) {
1100   CompoundFunc Op = getComplexOp(E->getOpcode());
1101   RValue Val;
1102   LValue Ret = ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
1103   Result = Val.getScalarVal();
1104   return Ret;
1105 }
1106