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/StmtVisitor.h"
17 #include "llvm/ADT/STLExtras.h"
18 #include "llvm/IR/Constants.h"
19 #include "llvm/IR/Instructions.h"
20 #include "llvm/IR/MDBuilder.h"
21 #include "llvm/IR/Metadata.h"
22 #include <algorithm>
23 using namespace clang;
24 using namespace CodeGen;
25 
26 //===----------------------------------------------------------------------===//
27 //                        Complex Expression Emitter
28 //===----------------------------------------------------------------------===//
29 
30 typedef CodeGenFunction::ComplexPairTy ComplexPairTy;
31 
32 /// Return the complex type that we are meant to emit.
33 static const ComplexType *getComplexType(QualType type) {
34   type = type.getCanonicalType();
35   if (const ComplexType *comp = dyn_cast<ComplexType>(type)) {
36     return comp;
37   } else {
38     return cast<ComplexType>(cast<AtomicType>(type)->getValueType());
39   }
40 }
41 
42 namespace  {
43 class ComplexExprEmitter
44   : public StmtVisitor<ComplexExprEmitter, ComplexPairTy> {
45   CodeGenFunction &CGF;
46   CGBuilderTy &Builder;
47   bool IgnoreReal;
48   bool IgnoreImag;
49 public:
50   ComplexExprEmitter(CodeGenFunction &cgf, bool ir=false, bool ii=false)
51     : CGF(cgf), Builder(CGF.Builder), IgnoreReal(ir), IgnoreImag(ii) {
52   }
53 
54 
55   //===--------------------------------------------------------------------===//
56   //                               Utilities
57   //===--------------------------------------------------------------------===//
58 
59   bool TestAndClearIgnoreReal() {
60     bool I = IgnoreReal;
61     IgnoreReal = false;
62     return I;
63   }
64   bool TestAndClearIgnoreImag() {
65     bool I = IgnoreImag;
66     IgnoreImag = false;
67     return I;
68   }
69 
70   /// EmitLoadOfLValue - Given an expression with complex type that represents a
71   /// value l-value, this method emits the address of the l-value, then loads
72   /// and returns the result.
73   ComplexPairTy EmitLoadOfLValue(const Expr *E) {
74     return EmitLoadOfLValue(CGF.EmitLValue(E), E->getExprLoc());
75   }
76 
77   ComplexPairTy EmitLoadOfLValue(LValue LV, SourceLocation Loc);
78 
79   /// EmitStoreOfComplex - Store the specified real/imag parts into the
80   /// specified value pointer.
81   void EmitStoreOfComplex(ComplexPairTy Val, LValue LV, bool isInit);
82 
83   /// Emit a cast from complex value Val to DestType.
84   ComplexPairTy EmitComplexToComplexCast(ComplexPairTy Val, QualType SrcType,
85                                          QualType DestType, SourceLocation Loc);
86   /// Emit a cast from scalar value Val to DestType.
87   ComplexPairTy EmitScalarToComplexCast(llvm::Value *Val, QualType SrcType,
88                                         QualType DestType, SourceLocation Loc);
89 
90   //===--------------------------------------------------------------------===//
91   //                            Visitor Methods
92   //===--------------------------------------------------------------------===//
93 
94   ComplexPairTy Visit(Expr *E) {
95     ApplyDebugLocation DL(CGF, E);
96     return StmtVisitor<ComplexExprEmitter, ComplexPairTy>::Visit(E);
97   }
98 
99   ComplexPairTy VisitStmt(Stmt *S) {
100     S->dump(CGF.getContext().getSourceManager());
101     llvm_unreachable("Stmt can't have complex result type!");
102   }
103   ComplexPairTy VisitExpr(Expr *S);
104   ComplexPairTy VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr());}
105   ComplexPairTy VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
106     return Visit(GE->getResultExpr());
107   }
108   ComplexPairTy VisitImaginaryLiteral(const ImaginaryLiteral *IL);
109   ComplexPairTy
110   VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *PE) {
111     return Visit(PE->getReplacement());
112   }
113 
114   // l-values.
115   ComplexPairTy VisitDeclRefExpr(DeclRefExpr *E) {
116     if (CodeGenFunction::ConstantEmission result = CGF.tryEmitAsConstant(E)) {
117       if (result.isReference())
118         return EmitLoadOfLValue(result.getReferenceLValue(CGF, E),
119                                 E->getExprLoc());
120 
121       llvm::Constant *pair = result.getValue();
122       return ComplexPairTy(pair->getAggregateElement(0U),
123                            pair->getAggregateElement(1U));
124     }
125     return EmitLoadOfLValue(E);
126   }
127   ComplexPairTy VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
128     return EmitLoadOfLValue(E);
129   }
130   ComplexPairTy VisitObjCMessageExpr(ObjCMessageExpr *E) {
131     return CGF.EmitObjCMessageExpr(E).getComplexVal();
132   }
133   ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
134   ComplexPairTy VisitMemberExpr(const Expr *E) { return EmitLoadOfLValue(E); }
135   ComplexPairTy VisitOpaqueValueExpr(OpaqueValueExpr *E) {
136     if (E->isGLValue())
137       return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E), E->getExprLoc());
138     return CGF.getOpaqueRValueMapping(E).getComplexVal();
139   }
140 
141   ComplexPairTy VisitPseudoObjectExpr(PseudoObjectExpr *E) {
142     return CGF.EmitPseudoObjectRValue(E).getComplexVal();
143   }
144 
145   // FIXME: CompoundLiteralExpr
146 
147   ComplexPairTy EmitCast(CastKind CK, Expr *Op, QualType DestTy);
148   ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
149     // Unlike for scalars, we don't have to worry about function->ptr demotion
150     // here.
151     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
152   }
153   ComplexPairTy VisitCastExpr(CastExpr *E) {
154     if (const auto *ECE = dyn_cast<ExplicitCastExpr>(E))
155       CGF.CGM.EmitExplicitCastExprType(ECE, &CGF);
156     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
157   }
158   ComplexPairTy VisitCallExpr(const CallExpr *E);
159   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
160 
161   // Operators.
162   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
163                                    bool isInc, bool isPre) {
164     LValue LV = CGF.EmitLValue(E->getSubExpr());
165     return CGF.EmitComplexPrePostIncDec(E, LV, isInc, isPre);
166   }
167   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
168     return VisitPrePostIncDec(E, false, false);
169   }
170   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
171     return VisitPrePostIncDec(E, true, false);
172   }
173   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
174     return VisitPrePostIncDec(E, false, true);
175   }
176   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
177     return VisitPrePostIncDec(E, true, true);
178   }
179   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
180   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
181     TestAndClearIgnoreReal();
182     TestAndClearIgnoreImag();
183     return Visit(E->getSubExpr());
184   }
185   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
186   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
187   // LNot,Real,Imag never return complex.
188   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
189     return Visit(E->getSubExpr());
190   }
191   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
192     return Visit(DAE->getExpr());
193   }
194   ComplexPairTy VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
195     CodeGenFunction::CXXDefaultInitExprScope Scope(CGF);
196     return Visit(DIE->getExpr());
197   }
198   ComplexPairTy VisitExprWithCleanups(ExprWithCleanups *E) {
199     CGF.enterFullExpression(E);
200     CodeGenFunction::RunCleanupsScope Scope(CGF);
201     ComplexPairTy Vals = Visit(E->getSubExpr());
202     // Defend against dominance problems caused by jumps out of expression
203     // evaluation through the shared cleanup block.
204     Scope.ForceCleanup({&Vals.first, &Vals.second});
205     return Vals;
206   }
207   ComplexPairTy VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
208     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
209     QualType Elem = E->getType()->castAs<ComplexType>()->getElementType();
210     llvm::Constant *Null = llvm::Constant::getNullValue(CGF.ConvertType(Elem));
211     return ComplexPairTy(Null, Null);
212   }
213   ComplexPairTy VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
214     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
215     QualType Elem = E->getType()->castAs<ComplexType>()->getElementType();
216     llvm::Constant *Null =
217                        llvm::Constant::getNullValue(CGF.ConvertType(Elem));
218     return ComplexPairTy(Null, Null);
219   }
220 
221   struct BinOpInfo {
222     ComplexPairTy LHS;
223     ComplexPairTy RHS;
224     QualType Ty;  // Computation Type.
225   };
226 
227   BinOpInfo EmitBinOps(const BinaryOperator *E);
228   LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
229                                   ComplexPairTy (ComplexExprEmitter::*Func)
230                                   (const BinOpInfo &),
231                                   RValue &Val);
232   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
233                                    ComplexPairTy (ComplexExprEmitter::*Func)
234                                    (const BinOpInfo &));
235 
236   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
237   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
238   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
239   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
240 
241   ComplexPairTy EmitComplexBinOpLibCall(StringRef LibCallName,
242                                         const BinOpInfo &Op);
243 
244   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
245     return EmitBinAdd(EmitBinOps(E));
246   }
247   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
248     return EmitBinSub(EmitBinOps(E));
249   }
250   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
251     return EmitBinMul(EmitBinOps(E));
252   }
253   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
254     return EmitBinDiv(EmitBinOps(E));
255   }
256 
257   // Compound assignments.
258   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
259     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
260   }
261   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
262     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
263   }
264   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
265     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
266   }
267   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
268     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
269   }
270 
271   // GCC rejects rem/and/or/xor for integer complex.
272   // Logical and/or always return int, never complex.
273 
274   // No comparisons produce a complex result.
275 
276   LValue EmitBinAssignLValue(const BinaryOperator *E,
277                              ComplexPairTy &Val);
278   ComplexPairTy VisitBinAssign     (const BinaryOperator *E);
279   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
280 
281 
282   ComplexPairTy
283   VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
284   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
285 
286   ComplexPairTy VisitInitListExpr(InitListExpr *E);
287 
288   ComplexPairTy VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
289     return EmitLoadOfLValue(E);
290   }
291 
292   ComplexPairTy VisitVAArgExpr(VAArgExpr *E);
293 
294   ComplexPairTy VisitAtomicExpr(AtomicExpr *E) {
295     return CGF.EmitAtomicExpr(E).getComplexVal();
296   }
297 };
298 }  // end anonymous namespace.
299 
300 //===----------------------------------------------------------------------===//
301 //                                Utilities
302 //===----------------------------------------------------------------------===//
303 
304 Address CodeGenFunction::emitAddrOfRealComponent(Address addr,
305                                                  QualType complexType) {
306   CharUnits offset = CharUnits::Zero();
307   return Builder.CreateStructGEP(addr, 0, offset, addr.getName() + ".realp");
308 }
309 
310 Address CodeGenFunction::emitAddrOfImagComponent(Address addr,
311                                                  QualType complexType) {
312   QualType eltType = complexType->castAs<ComplexType>()->getElementType();
313   CharUnits offset = getContext().getTypeSizeInChars(eltType);
314   return Builder.CreateStructGEP(addr, 1, offset, addr.getName() + ".imagp");
315 }
316 
317 /// EmitLoadOfLValue - Given an RValue reference for a complex, emit code to
318 /// load the real and imaginary pieces, returning them as Real/Imag.
319 ComplexPairTy ComplexExprEmitter::EmitLoadOfLValue(LValue lvalue,
320                                                    SourceLocation loc) {
321   assert(lvalue.isSimple() && "non-simple complex l-value?");
322   if (lvalue.getType()->isAtomicType())
323     return CGF.EmitAtomicLoad(lvalue, loc).getComplexVal();
324 
325   Address SrcPtr = lvalue.getAddress();
326   bool isVolatile = lvalue.isVolatileQualified();
327 
328   llvm::Value *Real = nullptr, *Imag = nullptr;
329 
330   if (!IgnoreReal || isVolatile) {
331     Address RealP = CGF.emitAddrOfRealComponent(SrcPtr, lvalue.getType());
332     Real = Builder.CreateLoad(RealP, isVolatile, SrcPtr.getName() + ".real");
333   }
334 
335   if (!IgnoreImag || isVolatile) {
336     Address ImagP = CGF.emitAddrOfImagComponent(SrcPtr, lvalue.getType());
337     Imag = Builder.CreateLoad(ImagP, isVolatile, SrcPtr.getName() + ".imag");
338   }
339 
340   return ComplexPairTy(Real, Imag);
341 }
342 
343 /// EmitStoreOfComplex - Store the specified real/imag parts into the
344 /// specified value pointer.
345 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, LValue lvalue,
346                                             bool isInit) {
347   if (lvalue.getType()->isAtomicType() ||
348       (!isInit && CGF.LValueIsSuitableForInlineAtomic(lvalue)))
349     return CGF.EmitAtomicStore(RValue::getComplex(Val), lvalue, isInit);
350 
351   Address Ptr = lvalue.getAddress();
352   Address RealPtr = CGF.emitAddrOfRealComponent(Ptr, lvalue.getType());
353   Address ImagPtr = CGF.emitAddrOfImagComponent(Ptr, lvalue.getType());
354 
355   Builder.CreateStore(Val.first, RealPtr, lvalue.isVolatileQualified());
356   Builder.CreateStore(Val.second, ImagPtr, lvalue.isVolatileQualified());
357 }
358 
359 
360 
361 //===----------------------------------------------------------------------===//
362 //                            Visitor Methods
363 //===----------------------------------------------------------------------===//
364 
365 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
366   CGF.ErrorUnsupported(E, "complex expression");
367   llvm::Type *EltTy =
368     CGF.ConvertType(getComplexType(E->getType())->getElementType());
369   llvm::Value *U = llvm::UndefValue::get(EltTy);
370   return ComplexPairTy(U, U);
371 }
372 
373 ComplexPairTy ComplexExprEmitter::
374 VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
375   llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
376   return ComplexPairTy(llvm::Constant::getNullValue(Imag->getType()), Imag);
377 }
378 
379 
380 ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
381   if (E->getCallReturnType(CGF.getContext())->isReferenceType())
382     return EmitLoadOfLValue(E);
383 
384   return CGF.EmitCallExpr(E).getComplexVal();
385 }
386 
387 ComplexPairTy ComplexExprEmitter::VisitStmtExpr(const StmtExpr *E) {
388   CodeGenFunction::StmtExprEvaluation eval(CGF);
389   Address RetAlloca = CGF.EmitCompoundStmt(*E->getSubStmt(), true);
390   assert(RetAlloca.isValid() && "Expected complex return value");
391   return EmitLoadOfLValue(CGF.MakeAddrLValue(RetAlloca, E->getType()),
392                           E->getExprLoc());
393 }
394 
395 /// Emit a cast from complex value Val to DestType.
396 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
397                                                            QualType SrcType,
398                                                            QualType DestType,
399                                                            SourceLocation Loc) {
400   // Get the src/dest element type.
401   SrcType = SrcType->castAs<ComplexType>()->getElementType();
402   DestType = DestType->castAs<ComplexType>()->getElementType();
403 
404   // C99 6.3.1.6: When a value of complex type is converted to another
405   // complex type, both the real and imaginary parts follow the conversion
406   // rules for the corresponding real types.
407   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType, Loc);
408   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType, Loc);
409   return Val;
410 }
411 
412 ComplexPairTy ComplexExprEmitter::EmitScalarToComplexCast(llvm::Value *Val,
413                                                           QualType SrcType,
414                                                           QualType DestType,
415                                                           SourceLocation Loc) {
416   // Convert the input element to the element type of the complex.
417   DestType = DestType->castAs<ComplexType>()->getElementType();
418   Val = CGF.EmitScalarConversion(Val, SrcType, DestType, Loc);
419 
420   // Return (realval, 0).
421   return ComplexPairTy(Val, llvm::Constant::getNullValue(Val->getType()));
422 }
423 
424 ComplexPairTy ComplexExprEmitter::EmitCast(CastKind CK, Expr *Op,
425                                            QualType DestTy) {
426   switch (CK) {
427   case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!");
428 
429   // Atomic to non-atomic casts may be more than a no-op for some platforms and
430   // for some types.
431   case CK_AtomicToNonAtomic:
432   case CK_NonAtomicToAtomic:
433   case CK_NoOp:
434   case CK_LValueToRValue:
435   case CK_UserDefinedConversion:
436     return Visit(Op);
437 
438   case CK_LValueBitCast: {
439     LValue origLV = CGF.EmitLValue(Op);
440     Address V = origLV.getAddress();
441     V = Builder.CreateElementBitCast(V, CGF.ConvertType(DestTy));
442     return EmitLoadOfLValue(CGF.MakeAddrLValue(V, DestTy), Op->getExprLoc());
443   }
444 
445   case CK_BitCast:
446   case CK_BaseToDerived:
447   case CK_DerivedToBase:
448   case CK_UncheckedDerivedToBase:
449   case CK_Dynamic:
450   case CK_ToUnion:
451   case CK_ArrayToPointerDecay:
452   case CK_FunctionToPointerDecay:
453   case CK_NullToPointer:
454   case CK_NullToMemberPointer:
455   case CK_BaseToDerivedMemberPointer:
456   case CK_DerivedToBaseMemberPointer:
457   case CK_MemberPointerToBoolean:
458   case CK_ReinterpretMemberPointer:
459   case CK_ConstructorConversion:
460   case CK_IntegralToPointer:
461   case CK_PointerToIntegral:
462   case CK_PointerToBoolean:
463   case CK_ToVoid:
464   case CK_VectorSplat:
465   case CK_IntegralCast:
466   case CK_BooleanToSignedIntegral:
467   case CK_IntegralToBoolean:
468   case CK_IntegralToFloating:
469   case CK_FloatingToIntegral:
470   case CK_FloatingToBoolean:
471   case CK_FloatingCast:
472   case CK_CPointerToObjCPointerCast:
473   case CK_BlockPointerToObjCPointerCast:
474   case CK_AnyPointerToBlockPointerCast:
475   case CK_ObjCObjectLValueCast:
476   case CK_FloatingComplexToReal:
477   case CK_FloatingComplexToBoolean:
478   case CK_IntegralComplexToReal:
479   case CK_IntegralComplexToBoolean:
480   case CK_ARCProduceObject:
481   case CK_ARCConsumeObject:
482   case CK_ARCReclaimReturnedObject:
483   case CK_ARCExtendBlockObject:
484   case CK_CopyAndAutoreleaseBlockObject:
485   case CK_BuiltinFnToFnPtr:
486   case CK_ZeroToOCLEvent:
487   case CK_ZeroToOCLQueue:
488   case CK_AddressSpaceConversion:
489   case CK_IntToOCLSampler:
490     llvm_unreachable("invalid cast kind for complex value");
491 
492   case CK_FloatingRealToComplex:
493   case CK_IntegralRealToComplex:
494     return EmitScalarToComplexCast(CGF.EmitScalarExpr(Op), Op->getType(),
495                                    DestTy, Op->getExprLoc());
496 
497   case CK_FloatingComplexCast:
498   case CK_FloatingComplexToIntegralComplex:
499   case CK_IntegralComplexCast:
500   case CK_IntegralComplexToFloatingComplex:
501     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy,
502                                     Op->getExprLoc());
503   }
504 
505   llvm_unreachable("unknown cast resulting in complex value");
506 }
507 
508 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
509   TestAndClearIgnoreReal();
510   TestAndClearIgnoreImag();
511   ComplexPairTy Op = Visit(E->getSubExpr());
512 
513   llvm::Value *ResR, *ResI;
514   if (Op.first->getType()->isFloatingPointTy()) {
515     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
516     ResI = Builder.CreateFNeg(Op.second, "neg.i");
517   } else {
518     ResR = Builder.CreateNeg(Op.first,  "neg.r");
519     ResI = Builder.CreateNeg(Op.second, "neg.i");
520   }
521   return ComplexPairTy(ResR, ResI);
522 }
523 
524 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
525   TestAndClearIgnoreReal();
526   TestAndClearIgnoreImag();
527   // ~(a+ib) = a + i*-b
528   ComplexPairTy Op = Visit(E->getSubExpr());
529   llvm::Value *ResI;
530   if (Op.second->getType()->isFloatingPointTy())
531     ResI = Builder.CreateFNeg(Op.second, "conj.i");
532   else
533     ResI = Builder.CreateNeg(Op.second, "conj.i");
534 
535   return ComplexPairTy(Op.first, ResI);
536 }
537 
538 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
539   llvm::Value *ResR, *ResI;
540 
541   if (Op.LHS.first->getType()->isFloatingPointTy()) {
542     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
543     if (Op.LHS.second && Op.RHS.second)
544       ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
545     else
546       ResI = Op.LHS.second ? Op.LHS.second : Op.RHS.second;
547     assert(ResI && "Only one operand may be real!");
548   } else {
549     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
550     assert(Op.LHS.second && Op.RHS.second &&
551            "Both operands of integer complex operators must be complex!");
552     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
553   }
554   return ComplexPairTy(ResR, ResI);
555 }
556 
557 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
558   llvm::Value *ResR, *ResI;
559   if (Op.LHS.first->getType()->isFloatingPointTy()) {
560     ResR = Builder.CreateFSub(Op.LHS.first, Op.RHS.first, "sub.r");
561     if (Op.LHS.second && Op.RHS.second)
562       ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
563     else
564       ResI = Op.LHS.second ? Op.LHS.second
565                            : Builder.CreateFNeg(Op.RHS.second, "sub.i");
566     assert(ResI && "Only one operand may be real!");
567   } else {
568     ResR = Builder.CreateSub(Op.LHS.first, Op.RHS.first, "sub.r");
569     assert(Op.LHS.second && Op.RHS.second &&
570            "Both operands of integer complex operators must be complex!");
571     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
572   }
573   return ComplexPairTy(ResR, ResI);
574 }
575 
576 /// \brief Emit a libcall for a binary operation on complex types.
577 ComplexPairTy ComplexExprEmitter::EmitComplexBinOpLibCall(StringRef LibCallName,
578                                                           const BinOpInfo &Op) {
579   CallArgList Args;
580   Args.add(RValue::get(Op.LHS.first),
581            Op.Ty->castAs<ComplexType>()->getElementType());
582   Args.add(RValue::get(Op.LHS.second),
583            Op.Ty->castAs<ComplexType>()->getElementType());
584   Args.add(RValue::get(Op.RHS.first),
585            Op.Ty->castAs<ComplexType>()->getElementType());
586   Args.add(RValue::get(Op.RHS.second),
587            Op.Ty->castAs<ComplexType>()->getElementType());
588 
589   // We *must* use the full CG function call building logic here because the
590   // complex type has special ABI handling. We also should not forget about
591   // special calling convention which may be used for compiler builtins.
592 
593   // We create a function qualified type to state that this call does not have
594   // any exceptions.
595   FunctionProtoType::ExtProtoInfo EPI;
596   EPI = EPI.withExceptionSpec(
597       FunctionProtoType::ExceptionSpecInfo(EST_BasicNoexcept));
598   SmallVector<QualType, 4> ArgsQTys(
599       4, Op.Ty->castAs<ComplexType>()->getElementType());
600   QualType FQTy = CGF.getContext().getFunctionType(Op.Ty, ArgsQTys, EPI);
601   const CGFunctionInfo &FuncInfo = CGF.CGM.getTypes().arrangeFreeFunctionCall(
602       Args, cast<FunctionType>(FQTy.getTypePtr()), false);
603 
604   llvm::FunctionType *FTy = CGF.CGM.getTypes().GetFunctionType(FuncInfo);
605   llvm::Constant *Func = CGF.CGM.CreateBuiltinFunction(FTy, LibCallName);
606   CGCallee Callee = CGCallee::forDirect(Func, FQTy->getAs<FunctionProtoType>());
607 
608   llvm::Instruction *Call;
609   RValue Res = CGF.EmitCall(FuncInfo, Callee, ReturnValueSlot(), Args, &Call);
610   cast<llvm::CallInst>(Call)->setCallingConv(CGF.CGM.getBuiltinCC());
611   return Res.getComplexVal();
612 }
613 
614 /// \brief Lookup the libcall name for a given floating point type complex
615 /// multiply.
616 static StringRef getComplexMultiplyLibCallName(llvm::Type *Ty) {
617   switch (Ty->getTypeID()) {
618   default:
619     llvm_unreachable("Unsupported floating point type!");
620   case llvm::Type::HalfTyID:
621     return "__mulhc3";
622   case llvm::Type::FloatTyID:
623     return "__mulsc3";
624   case llvm::Type::DoubleTyID:
625     return "__muldc3";
626   case llvm::Type::PPC_FP128TyID:
627     return "__multc3";
628   case llvm::Type::X86_FP80TyID:
629     return "__mulxc3";
630   case llvm::Type::FP128TyID:
631     return "__multc3";
632   }
633 }
634 
635 // See C11 Annex G.5.1 for the semantics of multiplicative operators on complex
636 // typed values.
637 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
638   using llvm::Value;
639   Value *ResR, *ResI;
640   llvm::MDBuilder MDHelper(CGF.getLLVMContext());
641 
642   if (Op.LHS.first->getType()->isFloatingPointTy()) {
643     // The general formulation is:
644     // (a + ib) * (c + id) = (a * c - b * d) + i(a * d + b * c)
645     //
646     // But we can fold away components which would be zero due to a real
647     // operand according to C11 Annex G.5.1p2.
648     // FIXME: C11 also provides for imaginary types which would allow folding
649     // still more of this within the type system.
650 
651     if (Op.LHS.second && Op.RHS.second) {
652       // If both operands are complex, emit the core math directly, and then
653       // test for NaNs. If we find NaNs in the result, we delegate to a libcall
654       // to carefully re-compute the correct infinity representation if
655       // possible. The expectation is that the presence of NaNs here is
656       // *extremely* rare, and so the cost of the libcall is almost irrelevant.
657       // This is good, because the libcall re-computes the core multiplication
658       // exactly the same as we do here and re-tests for NaNs in order to be
659       // a generic complex*complex libcall.
660 
661       // First compute the four products.
662       Value *AC = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul_ac");
663       Value *BD = Builder.CreateFMul(Op.LHS.second, Op.RHS.second, "mul_bd");
664       Value *AD = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul_ad");
665       Value *BC = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul_bc");
666 
667       // The real part is the difference of the first two, the imaginary part is
668       // the sum of the second.
669       ResR = Builder.CreateFSub(AC, BD, "mul_r");
670       ResI = Builder.CreateFAdd(AD, BC, "mul_i");
671 
672       // Emit the test for the real part becoming NaN and create a branch to
673       // handle it. We test for NaN by comparing the number to itself.
674       Value *IsRNaN = Builder.CreateFCmpUNO(ResR, ResR, "isnan_cmp");
675       llvm::BasicBlock *ContBB = CGF.createBasicBlock("complex_mul_cont");
676       llvm::BasicBlock *INaNBB = CGF.createBasicBlock("complex_mul_imag_nan");
677       llvm::Instruction *Branch = Builder.CreateCondBr(IsRNaN, INaNBB, ContBB);
678       llvm::BasicBlock *OrigBB = Branch->getParent();
679 
680       // Give hint that we very much don't expect to see NaNs.
681       // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
682       llvm::MDNode *BrWeight = MDHelper.createBranchWeights(1, (1U << 20) - 1);
683       Branch->setMetadata(llvm::LLVMContext::MD_prof, BrWeight);
684 
685       // Now test the imaginary part and create its branch.
686       CGF.EmitBlock(INaNBB);
687       Value *IsINaN = Builder.CreateFCmpUNO(ResI, ResI, "isnan_cmp");
688       llvm::BasicBlock *LibCallBB = CGF.createBasicBlock("complex_mul_libcall");
689       Branch = Builder.CreateCondBr(IsINaN, LibCallBB, ContBB);
690       Branch->setMetadata(llvm::LLVMContext::MD_prof, BrWeight);
691 
692       // Now emit the libcall on this slowest of the slow paths.
693       CGF.EmitBlock(LibCallBB);
694       Value *LibCallR, *LibCallI;
695       std::tie(LibCallR, LibCallI) = EmitComplexBinOpLibCall(
696           getComplexMultiplyLibCallName(Op.LHS.first->getType()), Op);
697       Builder.CreateBr(ContBB);
698 
699       // Finally continue execution by phi-ing together the different
700       // computation paths.
701       CGF.EmitBlock(ContBB);
702       llvm::PHINode *RealPHI = Builder.CreatePHI(ResR->getType(), 3, "real_mul_phi");
703       RealPHI->addIncoming(ResR, OrigBB);
704       RealPHI->addIncoming(ResR, INaNBB);
705       RealPHI->addIncoming(LibCallR, LibCallBB);
706       llvm::PHINode *ImagPHI = Builder.CreatePHI(ResI->getType(), 3, "imag_mul_phi");
707       ImagPHI->addIncoming(ResI, OrigBB);
708       ImagPHI->addIncoming(ResI, INaNBB);
709       ImagPHI->addIncoming(LibCallI, LibCallBB);
710       return ComplexPairTy(RealPHI, ImagPHI);
711     }
712     assert((Op.LHS.second || Op.RHS.second) &&
713            "At least one operand must be complex!");
714 
715     // If either of the operands is a real rather than a complex, the
716     // imaginary component is ignored when computing the real component of the
717     // result.
718     ResR = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
719 
720     ResI = Op.LHS.second
721                ? Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il")
722                : Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
723   } else {
724     assert(Op.LHS.second && Op.RHS.second &&
725            "Both operands of integer complex operators must be complex!");
726     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
727     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second, "mul.rr");
728     ResR = Builder.CreateSub(ResRl, ResRr, "mul.r");
729 
730     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
731     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
732     ResI = Builder.CreateAdd(ResIl, ResIr, "mul.i");
733   }
734   return ComplexPairTy(ResR, ResI);
735 }
736 
737 // See C11 Annex G.5.1 for the semantics of multiplicative operators on complex
738 // typed values.
739 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
740   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
741   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
742 
743 
744   llvm::Value *DSTr, *DSTi;
745   if (LHSr->getType()->isFloatingPointTy()) {
746     // If we have a complex operand on the RHS, we delegate to a libcall to
747     // handle all of the complexities and minimize underflow/overflow cases.
748     //
749     // FIXME: We would be able to avoid the libcall in many places if we
750     // supported imaginary types in addition to complex types.
751     if (RHSi) {
752       BinOpInfo LibCallOp = Op;
753       // If LHS was a real, supply a null imaginary part.
754       if (!LHSi)
755         LibCallOp.LHS.second = llvm::Constant::getNullValue(LHSr->getType());
756 
757       StringRef LibCallName;
758       switch (LHSr->getType()->getTypeID()) {
759       default:
760         llvm_unreachable("Unsupported floating point type!");
761       case llvm::Type::HalfTyID:
762         return EmitComplexBinOpLibCall("__divhc3", LibCallOp);
763       case llvm::Type::FloatTyID:
764         return EmitComplexBinOpLibCall("__divsc3", LibCallOp);
765       case llvm::Type::DoubleTyID:
766         return EmitComplexBinOpLibCall("__divdc3", LibCallOp);
767       case llvm::Type::PPC_FP128TyID:
768         return EmitComplexBinOpLibCall("__divtc3", LibCallOp);
769       case llvm::Type::X86_FP80TyID:
770         return EmitComplexBinOpLibCall("__divxc3", LibCallOp);
771       case llvm::Type::FP128TyID:
772         return EmitComplexBinOpLibCall("__divtc3", LibCallOp);
773       }
774     }
775     assert(LHSi && "Can have at most one non-complex operand!");
776 
777     DSTr = Builder.CreateFDiv(LHSr, RHSr);
778     DSTi = Builder.CreateFDiv(LHSi, RHSr);
779   } else {
780     assert(Op.LHS.second && Op.RHS.second &&
781            "Both operands of integer complex operators must be complex!");
782     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
783     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr); // a*c
784     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi); // b*d
785     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2); // ac+bd
786 
787     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr); // c*c
788     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi); // d*d
789     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5); // cc+dd
790 
791     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr); // b*c
792     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi); // a*d
793     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8); // bc-ad
794 
795     if (Op.Ty->castAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
796       DSTr = Builder.CreateUDiv(Tmp3, Tmp6);
797       DSTi = Builder.CreateUDiv(Tmp9, Tmp6);
798     } else {
799       DSTr = Builder.CreateSDiv(Tmp3, Tmp6);
800       DSTi = Builder.CreateSDiv(Tmp9, Tmp6);
801     }
802   }
803 
804   return ComplexPairTy(DSTr, DSTi);
805 }
806 
807 ComplexExprEmitter::BinOpInfo
808 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
809   TestAndClearIgnoreReal();
810   TestAndClearIgnoreImag();
811   BinOpInfo Ops;
812   if (E->getLHS()->getType()->isRealFloatingType())
813     Ops.LHS = ComplexPairTy(CGF.EmitScalarExpr(E->getLHS()), nullptr);
814   else
815     Ops.LHS = Visit(E->getLHS());
816   if (E->getRHS()->getType()->isRealFloatingType())
817     Ops.RHS = ComplexPairTy(CGF.EmitScalarExpr(E->getRHS()), nullptr);
818   else
819     Ops.RHS = Visit(E->getRHS());
820 
821   Ops.Ty = E->getType();
822   return Ops;
823 }
824 
825 
826 LValue ComplexExprEmitter::
827 EmitCompoundAssignLValue(const CompoundAssignOperator *E,
828           ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&),
829                          RValue &Val) {
830   TestAndClearIgnoreReal();
831   TestAndClearIgnoreImag();
832   QualType LHSTy = E->getLHS()->getType();
833   if (const AtomicType *AT = LHSTy->getAs<AtomicType>())
834     LHSTy = AT->getValueType();
835 
836   BinOpInfo OpInfo;
837 
838   // Load the RHS and LHS operands.
839   // __block variables need to have the rhs evaluated first, plus this should
840   // improve codegen a little.
841   OpInfo.Ty = E->getComputationResultType();
842   QualType ComplexElementTy = cast<ComplexType>(OpInfo.Ty)->getElementType();
843 
844   // The RHS should have been converted to the computation type.
845   if (E->getRHS()->getType()->isRealFloatingType()) {
846     assert(
847         CGF.getContext()
848             .hasSameUnqualifiedType(ComplexElementTy, E->getRHS()->getType()));
849     OpInfo.RHS = ComplexPairTy(CGF.EmitScalarExpr(E->getRHS()), nullptr);
850   } else {
851     assert(CGF.getContext()
852                .hasSameUnqualifiedType(OpInfo.Ty, E->getRHS()->getType()));
853     OpInfo.RHS = Visit(E->getRHS());
854   }
855 
856   LValue LHS = CGF.EmitLValue(E->getLHS());
857 
858   // Load from the l-value and convert it.
859   SourceLocation Loc = E->getExprLoc();
860   if (LHSTy->isAnyComplexType()) {
861     ComplexPairTy LHSVal = EmitLoadOfLValue(LHS, Loc);
862     OpInfo.LHS = EmitComplexToComplexCast(LHSVal, LHSTy, OpInfo.Ty, Loc);
863   } else {
864     llvm::Value *LHSVal = CGF.EmitLoadOfScalar(LHS, Loc);
865     // For floating point real operands we can directly pass the scalar form
866     // to the binary operator emission and potentially get more efficient code.
867     if (LHSTy->isRealFloatingType()) {
868       if (!CGF.getContext().hasSameUnqualifiedType(ComplexElementTy, LHSTy))
869         LHSVal = CGF.EmitScalarConversion(LHSVal, LHSTy, ComplexElementTy, Loc);
870       OpInfo.LHS = ComplexPairTy(LHSVal, nullptr);
871     } else {
872       OpInfo.LHS = EmitScalarToComplexCast(LHSVal, LHSTy, OpInfo.Ty, Loc);
873     }
874   }
875 
876   // Expand the binary operator.
877   ComplexPairTy Result = (this->*Func)(OpInfo);
878 
879   // Truncate the result and store it into the LHS lvalue.
880   if (LHSTy->isAnyComplexType()) {
881     ComplexPairTy ResVal =
882         EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy, Loc);
883     EmitStoreOfComplex(ResVal, LHS, /*isInit*/ false);
884     Val = RValue::getComplex(ResVal);
885   } else {
886     llvm::Value *ResVal =
887         CGF.EmitComplexToScalarConversion(Result, OpInfo.Ty, LHSTy, Loc);
888     CGF.EmitStoreOfScalar(ResVal, LHS, /*isInit*/ false);
889     Val = RValue::get(ResVal);
890   }
891 
892   return LHS;
893 }
894 
895 // Compound assignments.
896 ComplexPairTy ComplexExprEmitter::
897 EmitCompoundAssign(const CompoundAssignOperator *E,
898                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
899   RValue Val;
900   LValue LV = EmitCompoundAssignLValue(E, Func, Val);
901 
902   // The result of an assignment in C is the assigned r-value.
903   if (!CGF.getLangOpts().CPlusPlus)
904     return Val.getComplexVal();
905 
906   // If the lvalue is non-volatile, return the computed value of the assignment.
907   if (!LV.isVolatileQualified())
908     return Val.getComplexVal();
909 
910   return EmitLoadOfLValue(LV, E->getExprLoc());
911 }
912 
913 LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
914                                                ComplexPairTy &Val) {
915   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
916                                                  E->getRHS()->getType()) &&
917          "Invalid assignment");
918   TestAndClearIgnoreReal();
919   TestAndClearIgnoreImag();
920 
921   // Emit the RHS.  __block variables need the RHS evaluated first.
922   Val = Visit(E->getRHS());
923 
924   // Compute the address to store into.
925   LValue LHS = CGF.EmitLValue(E->getLHS());
926 
927   // Store the result value into the LHS lvalue.
928   EmitStoreOfComplex(Val, LHS, /*isInit*/ false);
929 
930   return LHS;
931 }
932 
933 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
934   ComplexPairTy Val;
935   LValue LV = EmitBinAssignLValue(E, Val);
936 
937   // The result of an assignment in C is the assigned r-value.
938   if (!CGF.getLangOpts().CPlusPlus)
939     return Val;
940 
941   // If the lvalue is non-volatile, return the computed value of the assignment.
942   if (!LV.isVolatileQualified())
943     return Val;
944 
945   return EmitLoadOfLValue(LV, E->getExprLoc());
946 }
947 
948 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
949   CGF.EmitIgnoredExpr(E->getLHS());
950   return Visit(E->getRHS());
951 }
952 
953 ComplexPairTy ComplexExprEmitter::
954 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
955   TestAndClearIgnoreReal();
956   TestAndClearIgnoreImag();
957   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
958   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
959   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
960 
961   // Bind the common expression if necessary.
962   CodeGenFunction::OpaqueValueMapping binding(CGF, E);
963 
964 
965   CodeGenFunction::ConditionalEvaluation eval(CGF);
966   CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock,
967                            CGF.getProfileCount(E));
968 
969   eval.begin(CGF);
970   CGF.EmitBlock(LHSBlock);
971   CGF.incrementProfileCounter(E);
972   ComplexPairTy LHS = Visit(E->getTrueExpr());
973   LHSBlock = Builder.GetInsertBlock();
974   CGF.EmitBranch(ContBlock);
975   eval.end(CGF);
976 
977   eval.begin(CGF);
978   CGF.EmitBlock(RHSBlock);
979   ComplexPairTy RHS = Visit(E->getFalseExpr());
980   RHSBlock = Builder.GetInsertBlock();
981   CGF.EmitBlock(ContBlock);
982   eval.end(CGF);
983 
984   // Create a PHI node for the real part.
985   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.r");
986   RealPN->addIncoming(LHS.first, LHSBlock);
987   RealPN->addIncoming(RHS.first, RHSBlock);
988 
989   // Create a PHI node for the imaginary part.
990   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.i");
991   ImagPN->addIncoming(LHS.second, LHSBlock);
992   ImagPN->addIncoming(RHS.second, RHSBlock);
993 
994   return ComplexPairTy(RealPN, ImagPN);
995 }
996 
997 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
998   return Visit(E->getChosenSubExpr());
999 }
1000 
1001 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
1002     bool Ignore = TestAndClearIgnoreReal();
1003     (void)Ignore;
1004     assert (Ignore == false && "init list ignored");
1005     Ignore = TestAndClearIgnoreImag();
1006     (void)Ignore;
1007     assert (Ignore == false && "init list ignored");
1008 
1009   if (E->getNumInits() == 2) {
1010     llvm::Value *Real = CGF.EmitScalarExpr(E->getInit(0));
1011     llvm::Value *Imag = CGF.EmitScalarExpr(E->getInit(1));
1012     return ComplexPairTy(Real, Imag);
1013   } else if (E->getNumInits() == 1) {
1014     return Visit(E->getInit(0));
1015   }
1016 
1017   // Empty init list intializes to null
1018   assert(E->getNumInits() == 0 && "Unexpected number of inits");
1019   QualType Ty = E->getType()->castAs<ComplexType>()->getElementType();
1020   llvm::Type* LTy = CGF.ConvertType(Ty);
1021   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
1022   return ComplexPairTy(zeroConstant, zeroConstant);
1023 }
1024 
1025 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
1026   Address ArgValue = Address::invalid();
1027   Address ArgPtr = CGF.EmitVAArg(E, ArgValue);
1028 
1029   if (!ArgPtr.isValid()) {
1030     CGF.ErrorUnsupported(E, "complex va_arg expression");
1031     llvm::Type *EltTy =
1032       CGF.ConvertType(E->getType()->castAs<ComplexType>()->getElementType());
1033     llvm::Value *U = llvm::UndefValue::get(EltTy);
1034     return ComplexPairTy(U, U);
1035   }
1036 
1037   return EmitLoadOfLValue(CGF.MakeAddrLValue(ArgPtr, E->getType()),
1038                           E->getExprLoc());
1039 }
1040 
1041 //===----------------------------------------------------------------------===//
1042 //                         Entry Point into this File
1043 //===----------------------------------------------------------------------===//
1044 
1045 /// EmitComplexExpr - Emit the computation of the specified expression of
1046 /// complex type, ignoring the result.
1047 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
1048                                                bool IgnoreImag) {
1049   assert(E && getComplexType(E->getType()) &&
1050          "Invalid complex expression to emit");
1051 
1052   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag)
1053       .Visit(const_cast<Expr *>(E));
1054 }
1055 
1056 void CodeGenFunction::EmitComplexExprIntoLValue(const Expr *E, LValue dest,
1057                                                 bool isInit) {
1058   assert(E && getComplexType(E->getType()) &&
1059          "Invalid complex expression to emit");
1060   ComplexExprEmitter Emitter(*this);
1061   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
1062   Emitter.EmitStoreOfComplex(Val, dest, isInit);
1063 }
1064 
1065 /// EmitStoreOfComplex - Store a complex number into the specified l-value.
1066 void CodeGenFunction::EmitStoreOfComplex(ComplexPairTy V, LValue dest,
1067                                          bool isInit) {
1068   ComplexExprEmitter(*this).EmitStoreOfComplex(V, dest, isInit);
1069 }
1070 
1071 /// EmitLoadOfComplex - Load a complex number from the specified address.
1072 ComplexPairTy CodeGenFunction::EmitLoadOfComplex(LValue src,
1073                                                  SourceLocation loc) {
1074   return ComplexExprEmitter(*this).EmitLoadOfLValue(src, loc);
1075 }
1076 
1077 LValue CodeGenFunction::EmitComplexAssignmentLValue(const BinaryOperator *E) {
1078   assert(E->getOpcode() == BO_Assign);
1079   ComplexPairTy Val; // ignored
1080   return ComplexExprEmitter(*this).EmitBinAssignLValue(E, Val);
1081 }
1082 
1083 typedef ComplexPairTy (ComplexExprEmitter::*CompoundFunc)(
1084     const ComplexExprEmitter::BinOpInfo &);
1085 
1086 static CompoundFunc getComplexOp(BinaryOperatorKind Op) {
1087   switch (Op) {
1088   case BO_MulAssign: return &ComplexExprEmitter::EmitBinMul;
1089   case BO_DivAssign: return &ComplexExprEmitter::EmitBinDiv;
1090   case BO_SubAssign: return &ComplexExprEmitter::EmitBinSub;
1091   case BO_AddAssign: return &ComplexExprEmitter::EmitBinAdd;
1092   default:
1093     llvm_unreachable("unexpected complex compound assignment");
1094   }
1095 }
1096 
1097 LValue CodeGenFunction::
1098 EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E) {
1099   CompoundFunc Op = getComplexOp(E->getOpcode());
1100   RValue Val;
1101   return ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
1102 }
1103 
1104 LValue CodeGenFunction::
1105 EmitScalarCompoundAssignWithComplex(const CompoundAssignOperator *E,
1106                                     llvm::Value *&Result) {
1107   CompoundFunc Op = getComplexOp(E->getOpcode());
1108   RValue Val;
1109   LValue Ret = ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
1110   Result = Val.getScalarVal();
1111   return Ret;
1112 }
1113