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     if (const auto *ECE = dyn_cast<ExplicitCastExpr>(E))
158       CGF.CGM.EmitExplicitCastExprType(ECE, &CGF);
159     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
160   }
161   ComplexPairTy VisitCallExpr(const CallExpr *E);
162   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
163 
164   // Operators.
165   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
166                                    bool isInc, bool isPre) {
167     LValue LV = CGF.EmitLValue(E->getSubExpr());
168     return CGF.EmitComplexPrePostIncDec(E, LV, isInc, isPre);
169   }
170   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
171     return VisitPrePostIncDec(E, false, false);
172   }
173   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
174     return VisitPrePostIncDec(E, true, false);
175   }
176   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
177     return VisitPrePostIncDec(E, false, true);
178   }
179   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
180     return VisitPrePostIncDec(E, true, true);
181   }
182   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
183   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
184     TestAndClearIgnoreReal();
185     TestAndClearIgnoreImag();
186     return Visit(E->getSubExpr());
187   }
188   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
189   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
190   // LNot,Real,Imag never return complex.
191   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
192     return Visit(E->getSubExpr());
193   }
194   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
195     return Visit(DAE->getExpr());
196   }
197   ComplexPairTy VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
198     CodeGenFunction::CXXDefaultInitExprScope Scope(CGF);
199     return Visit(DIE->getExpr());
200   }
201   ComplexPairTy VisitExprWithCleanups(ExprWithCleanups *E) {
202     CGF.enterFullExpression(E);
203     CodeGenFunction::RunCleanupsScope Scope(CGF);
204     return Visit(E->getSubExpr());
205   }
206   ComplexPairTy VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
207     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
208     QualType Elem = E->getType()->castAs<ComplexType>()->getElementType();
209     llvm::Constant *Null = llvm::Constant::getNullValue(CGF.ConvertType(Elem));
210     return ComplexPairTy(Null, Null);
211   }
212   ComplexPairTy VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
213     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
214     QualType Elem = E->getType()->castAs<ComplexType>()->getElementType();
215     llvm::Constant *Null =
216                        llvm::Constant::getNullValue(CGF.ConvertType(Elem));
217     return ComplexPairTy(Null, Null);
218   }
219 
220   struct BinOpInfo {
221     ComplexPairTy LHS;
222     ComplexPairTy RHS;
223     QualType Ty;  // Computation Type.
224   };
225 
226   BinOpInfo EmitBinOps(const BinaryOperator *E);
227   LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
228                                   ComplexPairTy (ComplexExprEmitter::*Func)
229                                   (const BinOpInfo &),
230                                   RValue &Val);
231   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
232                                    ComplexPairTy (ComplexExprEmitter::*Func)
233                                    (const BinOpInfo &));
234 
235   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
236   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
237   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
238   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
239 
240   ComplexPairTy EmitComplexBinOpLibCall(StringRef LibCallName,
241                                         const BinOpInfo &Op);
242 
243   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
244     return EmitBinAdd(EmitBinOps(E));
245   }
246   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
247     return EmitBinSub(EmitBinOps(E));
248   }
249   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
250     return EmitBinMul(EmitBinOps(E));
251   }
252   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
253     return EmitBinDiv(EmitBinOps(E));
254   }
255 
256   // Compound assignments.
257   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
258     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
259   }
260   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
261     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
262   }
263   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
264     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
265   }
266   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
267     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
268   }
269 
270   // GCC rejects rem/and/or/xor for integer complex.
271   // Logical and/or always return int, never complex.
272 
273   // No comparisons produce a complex result.
274 
275   LValue EmitBinAssignLValue(const BinaryOperator *E,
276                              ComplexPairTy &Val);
277   ComplexPairTy VisitBinAssign     (const BinaryOperator *E);
278   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
279 
280 
281   ComplexPairTy
282   VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
283   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
284 
285   ComplexPairTy VisitInitListExpr(InitListExpr *E);
286 
287   ComplexPairTy VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
288     return EmitLoadOfLValue(E);
289   }
290 
291   ComplexPairTy VisitVAArgExpr(VAArgExpr *E);
292 
293   ComplexPairTy VisitAtomicExpr(AtomicExpr *E) {
294     return CGF.EmitAtomicExpr(E).getComplexVal();
295   }
296 };
297 }  // end anonymous namespace.
298 
299 //===----------------------------------------------------------------------===//
300 //                                Utilities
301 //===----------------------------------------------------------------------===//
302 
303 Address CodeGenFunction::emitAddrOfRealComponent(Address addr,
304                                                  QualType complexType) {
305   CharUnits offset = CharUnits::Zero();
306   return Builder.CreateStructGEP(addr, 0, offset, addr.getName() + ".realp");
307 }
308 
309 Address CodeGenFunction::emitAddrOfImagComponent(Address addr,
310                                                  QualType complexType) {
311   QualType eltType = complexType->castAs<ComplexType>()->getElementType();
312   CharUnits offset = getContext().getTypeSizeInChars(eltType);
313   return Builder.CreateStructGEP(addr, 1, offset, addr.getName() + ".imagp");
314 }
315 
316 /// EmitLoadOfLValue - Given an RValue reference for a complex, emit code to
317 /// load the real and imaginary pieces, returning them as Real/Imag.
318 ComplexPairTy ComplexExprEmitter::EmitLoadOfLValue(LValue lvalue,
319                                                    SourceLocation loc) {
320   assert(lvalue.isSimple() && "non-simple complex l-value?");
321   if (lvalue.getType()->isAtomicType())
322     return CGF.EmitAtomicLoad(lvalue, loc).getComplexVal();
323 
324   Address SrcPtr = lvalue.getAddress();
325   bool isVolatile = lvalue.isVolatileQualified();
326 
327   llvm::Value *Real = nullptr, *Imag = nullptr;
328 
329   if (!IgnoreReal || isVolatile) {
330     Address RealP = CGF.emitAddrOfRealComponent(SrcPtr, lvalue.getType());
331     Real = Builder.CreateLoad(RealP, isVolatile, SrcPtr.getName() + ".real");
332   }
333 
334   if (!IgnoreImag || isVolatile) {
335     Address ImagP = CGF.emitAddrOfImagComponent(SrcPtr, lvalue.getType());
336     Imag = Builder.CreateLoad(ImagP, isVolatile, SrcPtr.getName() + ".imag");
337   }
338 
339   return ComplexPairTy(Real, Imag);
340 }
341 
342 /// EmitStoreOfComplex - Store the specified real/imag parts into the
343 /// specified value pointer.
344 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, LValue lvalue,
345                                             bool isInit) {
346   if (lvalue.getType()->isAtomicType() ||
347       (!isInit && CGF.LValueIsSuitableForInlineAtomic(lvalue)))
348     return CGF.EmitAtomicStore(RValue::getComplex(Val), lvalue, isInit);
349 
350   Address Ptr = lvalue.getAddress();
351   Address RealPtr = CGF.emitAddrOfRealComponent(Ptr, lvalue.getType());
352   Address ImagPtr = CGF.emitAddrOfImagComponent(Ptr, lvalue.getType());
353 
354   Builder.CreateStore(Val.first, RealPtr, lvalue.isVolatileQualified());
355   Builder.CreateStore(Val.second, ImagPtr, 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   Address RetAlloca = CGF.EmitCompoundStmt(*E->getSubStmt(), true);
389   assert(RetAlloca.isValid() && "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     Address V = origLV.getAddress();
440     V = Builder.CreateElementBitCast(V, CGF.ConvertType(DestTy));
441     return EmitLoadOfLValue(CGF.MakeAddrLValue(V, DestTy), Op->getExprLoc());
442   }
443 
444   case CK_BitCast:
445   case CK_BaseToDerived:
446   case CK_DerivedToBase:
447   case CK_UncheckedDerivedToBase:
448   case CK_Dynamic:
449   case CK_ToUnion:
450   case CK_ArrayToPointerDecay:
451   case CK_FunctionToPointerDecay:
452   case CK_NullToPointer:
453   case CK_NullToMemberPointer:
454   case CK_BaseToDerivedMemberPointer:
455   case CK_DerivedToBaseMemberPointer:
456   case CK_MemberPointerToBoolean:
457   case CK_ReinterpretMemberPointer:
458   case CK_ConstructorConversion:
459   case CK_IntegralToPointer:
460   case CK_PointerToIntegral:
461   case CK_PointerToBoolean:
462   case CK_ToVoid:
463   case CK_VectorSplat:
464   case CK_IntegralCast:
465   case CK_IntegralToBoolean:
466   case CK_IntegralToFloating:
467   case CK_FloatingToIntegral:
468   case CK_FloatingToBoolean:
469   case CK_FloatingCast:
470   case CK_CPointerToObjCPointerCast:
471   case CK_BlockPointerToObjCPointerCast:
472   case CK_AnyPointerToBlockPointerCast:
473   case CK_ObjCObjectLValueCast:
474   case CK_FloatingComplexToReal:
475   case CK_FloatingComplexToBoolean:
476   case CK_IntegralComplexToReal:
477   case CK_IntegralComplexToBoolean:
478   case CK_ARCProduceObject:
479   case CK_ARCConsumeObject:
480   case CK_ARCReclaimReturnedObject:
481   case CK_ARCExtendBlockObject:
482   case CK_CopyAndAutoreleaseBlockObject:
483   case CK_BuiltinFnToFnPtr:
484   case CK_ZeroToOCLEvent:
485   case CK_AddressSpaceConversion:
486     llvm_unreachable("invalid cast kind for complex value");
487 
488   case CK_FloatingRealToComplex:
489   case CK_IntegralRealToComplex:
490     return EmitScalarToComplexCast(CGF.EmitScalarExpr(Op), Op->getType(),
491                                    DestTy, Op->getExprLoc());
492 
493   case CK_FloatingComplexCast:
494   case CK_FloatingComplexToIntegralComplex:
495   case CK_IntegralComplexCast:
496   case CK_IntegralComplexToFloatingComplex:
497     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy,
498                                     Op->getExprLoc());
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   SourceLocation Loc = E->getExprLoc();
850   if (LHSTy->isAnyComplexType()) {
851     ComplexPairTy LHSVal = EmitLoadOfLValue(LHS, Loc);
852     OpInfo.LHS = EmitComplexToComplexCast(LHSVal, LHSTy, OpInfo.Ty, Loc);
853   } else {
854     llvm::Value *LHSVal = CGF.EmitLoadOfScalar(LHS, Loc);
855     // For floating point real operands we can directly pass the scalar form
856     // to the binary operator emission and potentially get more efficient code.
857     if (LHSTy->isRealFloatingType()) {
858       if (!CGF.getContext().hasSameUnqualifiedType(ComplexElementTy, LHSTy))
859         LHSVal = CGF.EmitScalarConversion(LHSVal, LHSTy, ComplexElementTy, Loc);
860       OpInfo.LHS = ComplexPairTy(LHSVal, nullptr);
861     } else {
862       OpInfo.LHS = EmitScalarToComplexCast(LHSVal, LHSTy, OpInfo.Ty, Loc);
863     }
864   }
865 
866   // Expand the binary operator.
867   ComplexPairTy Result = (this->*Func)(OpInfo);
868 
869   // Truncate the result and store it into the LHS lvalue.
870   if (LHSTy->isAnyComplexType()) {
871     ComplexPairTy ResVal =
872         EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy, Loc);
873     EmitStoreOfComplex(ResVal, LHS, /*isInit*/ false);
874     Val = RValue::getComplex(ResVal);
875   } else {
876     llvm::Value *ResVal =
877         CGF.EmitComplexToScalarConversion(Result, OpInfo.Ty, LHSTy, Loc);
878     CGF.EmitStoreOfScalar(ResVal, LHS, /*isInit*/ false);
879     Val = RValue::get(ResVal);
880   }
881 
882   return LHS;
883 }
884 
885 // Compound assignments.
886 ComplexPairTy ComplexExprEmitter::
887 EmitCompoundAssign(const CompoundAssignOperator *E,
888                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
889   RValue Val;
890   LValue LV = EmitCompoundAssignLValue(E, Func, Val);
891 
892   // The result of an assignment in C is the assigned r-value.
893   if (!CGF.getLangOpts().CPlusPlus)
894     return Val.getComplexVal();
895 
896   // If the lvalue is non-volatile, return the computed value of the assignment.
897   if (!LV.isVolatileQualified())
898     return Val.getComplexVal();
899 
900   return EmitLoadOfLValue(LV, E->getExprLoc());
901 }
902 
903 LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
904                                                ComplexPairTy &Val) {
905   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
906                                                  E->getRHS()->getType()) &&
907          "Invalid assignment");
908   TestAndClearIgnoreReal();
909   TestAndClearIgnoreImag();
910 
911   // Emit the RHS.  __block variables need the RHS evaluated first.
912   Val = Visit(E->getRHS());
913 
914   // Compute the address to store into.
915   LValue LHS = CGF.EmitLValue(E->getLHS());
916 
917   // Store the result value into the LHS lvalue.
918   EmitStoreOfComplex(Val, LHS, /*isInit*/ false);
919 
920   return LHS;
921 }
922 
923 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
924   ComplexPairTy Val;
925   LValue LV = EmitBinAssignLValue(E, Val);
926 
927   // The result of an assignment in C is the assigned r-value.
928   if (!CGF.getLangOpts().CPlusPlus)
929     return Val;
930 
931   // If the lvalue is non-volatile, return the computed value of the assignment.
932   if (!LV.isVolatileQualified())
933     return Val;
934 
935   return EmitLoadOfLValue(LV, E->getExprLoc());
936 }
937 
938 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
939   CGF.EmitIgnoredExpr(E->getLHS());
940   return Visit(E->getRHS());
941 }
942 
943 ComplexPairTy ComplexExprEmitter::
944 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
945   TestAndClearIgnoreReal();
946   TestAndClearIgnoreImag();
947   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
948   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
949   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
950 
951   // Bind the common expression if necessary.
952   CodeGenFunction::OpaqueValueMapping binding(CGF, E);
953 
954 
955   CodeGenFunction::ConditionalEvaluation eval(CGF);
956   CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock,
957                            CGF.getProfileCount(E));
958 
959   eval.begin(CGF);
960   CGF.EmitBlock(LHSBlock);
961   CGF.incrementProfileCounter(E);
962   ComplexPairTy LHS = Visit(E->getTrueExpr());
963   LHSBlock = Builder.GetInsertBlock();
964   CGF.EmitBranch(ContBlock);
965   eval.end(CGF);
966 
967   eval.begin(CGF);
968   CGF.EmitBlock(RHSBlock);
969   ComplexPairTy RHS = Visit(E->getFalseExpr());
970   RHSBlock = Builder.GetInsertBlock();
971   CGF.EmitBlock(ContBlock);
972   eval.end(CGF);
973 
974   // Create a PHI node for the real part.
975   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.r");
976   RealPN->addIncoming(LHS.first, LHSBlock);
977   RealPN->addIncoming(RHS.first, RHSBlock);
978 
979   // Create a PHI node for the imaginary part.
980   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.i");
981   ImagPN->addIncoming(LHS.second, LHSBlock);
982   ImagPN->addIncoming(RHS.second, RHSBlock);
983 
984   return ComplexPairTy(RealPN, ImagPN);
985 }
986 
987 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
988   return Visit(E->getChosenSubExpr());
989 }
990 
991 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
992     bool Ignore = TestAndClearIgnoreReal();
993     (void)Ignore;
994     assert (Ignore == false && "init list ignored");
995     Ignore = TestAndClearIgnoreImag();
996     (void)Ignore;
997     assert (Ignore == false && "init list ignored");
998 
999   if (E->getNumInits() == 2) {
1000     llvm::Value *Real = CGF.EmitScalarExpr(E->getInit(0));
1001     llvm::Value *Imag = CGF.EmitScalarExpr(E->getInit(1));
1002     return ComplexPairTy(Real, Imag);
1003   } else if (E->getNumInits() == 1) {
1004     return Visit(E->getInit(0));
1005   }
1006 
1007   // Empty init list intializes to null
1008   assert(E->getNumInits() == 0 && "Unexpected number of inits");
1009   QualType Ty = E->getType()->castAs<ComplexType>()->getElementType();
1010   llvm::Type* LTy = CGF.ConvertType(Ty);
1011   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
1012   return ComplexPairTy(zeroConstant, zeroConstant);
1013 }
1014 
1015 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
1016   Address ArgValue = Address::invalid();
1017   Address ArgPtr = CGF.EmitVAArg(E, ArgValue);
1018 
1019   if (!ArgPtr.isValid()) {
1020     CGF.ErrorUnsupported(E, "complex va_arg expression");
1021     llvm::Type *EltTy =
1022       CGF.ConvertType(E->getType()->castAs<ComplexType>()->getElementType());
1023     llvm::Value *U = llvm::UndefValue::get(EltTy);
1024     return ComplexPairTy(U, U);
1025   }
1026 
1027   return EmitLoadOfLValue(CGF.MakeAddrLValue(ArgPtr, E->getType()),
1028                           E->getExprLoc());
1029 }
1030 
1031 //===----------------------------------------------------------------------===//
1032 //                         Entry Point into this File
1033 //===----------------------------------------------------------------------===//
1034 
1035 /// EmitComplexExpr - Emit the computation of the specified expression of
1036 /// complex type, ignoring the result.
1037 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
1038                                                bool IgnoreImag) {
1039   assert(E && getComplexType(E->getType()) &&
1040          "Invalid complex expression to emit");
1041 
1042   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag)
1043       .Visit(const_cast<Expr *>(E));
1044 }
1045 
1046 void CodeGenFunction::EmitComplexExprIntoLValue(const Expr *E, LValue dest,
1047                                                 bool isInit) {
1048   assert(E && getComplexType(E->getType()) &&
1049          "Invalid complex expression to emit");
1050   ComplexExprEmitter Emitter(*this);
1051   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
1052   Emitter.EmitStoreOfComplex(Val, dest, isInit);
1053 }
1054 
1055 /// EmitStoreOfComplex - Store a complex number into the specified l-value.
1056 void CodeGenFunction::EmitStoreOfComplex(ComplexPairTy V, LValue dest,
1057                                          bool isInit) {
1058   ComplexExprEmitter(*this).EmitStoreOfComplex(V, dest, isInit);
1059 }
1060 
1061 /// EmitLoadOfComplex - Load a complex number from the specified address.
1062 ComplexPairTy CodeGenFunction::EmitLoadOfComplex(LValue src,
1063                                                  SourceLocation loc) {
1064   return ComplexExprEmitter(*this).EmitLoadOfLValue(src, loc);
1065 }
1066 
1067 LValue CodeGenFunction::EmitComplexAssignmentLValue(const BinaryOperator *E) {
1068   assert(E->getOpcode() == BO_Assign);
1069   ComplexPairTy Val; // ignored
1070   return ComplexExprEmitter(*this).EmitBinAssignLValue(E, Val);
1071 }
1072 
1073 typedef ComplexPairTy (ComplexExprEmitter::*CompoundFunc)(
1074     const ComplexExprEmitter::BinOpInfo &);
1075 
1076 static CompoundFunc getComplexOp(BinaryOperatorKind Op) {
1077   switch (Op) {
1078   case BO_MulAssign: return &ComplexExprEmitter::EmitBinMul;
1079   case BO_DivAssign: return &ComplexExprEmitter::EmitBinDiv;
1080   case BO_SubAssign: return &ComplexExprEmitter::EmitBinSub;
1081   case BO_AddAssign: return &ComplexExprEmitter::EmitBinAdd;
1082   default:
1083     llvm_unreachable("unexpected complex compound assignment");
1084   }
1085 }
1086 
1087 LValue CodeGenFunction::
1088 EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E) {
1089   CompoundFunc Op = getComplexOp(E->getOpcode());
1090   RValue Val;
1091   return ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
1092 }
1093 
1094 LValue CodeGenFunction::
1095 EmitScalarCompoundAssignWithComplex(const CompoundAssignOperator *E,
1096                                     llvm::Value *&Result) {
1097   CompoundFunc Op = getComplexOp(E->getOpcode());
1098   RValue Val;
1099   LValue Ret = ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
1100   Result = Val.getScalarVal();
1101   return Ret;
1102 }
1103