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