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_ZeroToOCLQueue:
484   case CK_AddressSpaceConversion:
485   case CK_IntToOCLSampler:
486     llvm_unreachable("invalid cast kind for complex value");
487 
488   case CK_FloatingRealToComplex:
489   case CK_IntegralRealToComplex:
490     return EmitScalarToComplexCast(CGF.EmitScalarExpr(Op), Op->getType(),
491                                    DestTy, Op->getExprLoc());
492 
493   case CK_FloatingComplexCast:
494   case CK_FloatingComplexToIntegralComplex:
495   case CK_IntegralComplexCast:
496   case CK_IntegralComplexToFloatingComplex:
497     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy,
498                                     Op->getExprLoc());
499   }
500 
501   llvm_unreachable("unknown cast resulting in complex value");
502 }
503 
504 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
505   TestAndClearIgnoreReal();
506   TestAndClearIgnoreImag();
507   ComplexPairTy Op = Visit(E->getSubExpr());
508 
509   llvm::Value *ResR, *ResI;
510   if (Op.first->getType()->isFloatingPointTy()) {
511     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
512     ResI = Builder.CreateFNeg(Op.second, "neg.i");
513   } else {
514     ResR = Builder.CreateNeg(Op.first,  "neg.r");
515     ResI = Builder.CreateNeg(Op.second, "neg.i");
516   }
517   return ComplexPairTy(ResR, ResI);
518 }
519 
520 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
521   TestAndClearIgnoreReal();
522   TestAndClearIgnoreImag();
523   // ~(a+ib) = a + i*-b
524   ComplexPairTy Op = Visit(E->getSubExpr());
525   llvm::Value *ResI;
526   if (Op.second->getType()->isFloatingPointTy())
527     ResI = Builder.CreateFNeg(Op.second, "conj.i");
528   else
529     ResI = Builder.CreateNeg(Op.second, "conj.i");
530 
531   return ComplexPairTy(Op.first, ResI);
532 }
533 
534 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
535   llvm::Value *ResR, *ResI;
536 
537   if (Op.LHS.first->getType()->isFloatingPointTy()) {
538     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
539     if (Op.LHS.second && Op.RHS.second)
540       ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
541     else
542       ResI = Op.LHS.second ? Op.LHS.second : Op.RHS.second;
543     assert(ResI && "Only one operand may be real!");
544   } else {
545     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
546     assert(Op.LHS.second && Op.RHS.second &&
547            "Both operands of integer complex operators must be complex!");
548     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
549   }
550   return ComplexPairTy(ResR, ResI);
551 }
552 
553 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
554   llvm::Value *ResR, *ResI;
555   if (Op.LHS.first->getType()->isFloatingPointTy()) {
556     ResR = Builder.CreateFSub(Op.LHS.first, Op.RHS.first, "sub.r");
557     if (Op.LHS.second && Op.RHS.second)
558       ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
559     else
560       ResI = Op.LHS.second ? Op.LHS.second
561                            : Builder.CreateFNeg(Op.RHS.second, "sub.i");
562     assert(ResI && "Only one operand may be real!");
563   } else {
564     ResR = Builder.CreateSub(Op.LHS.first, Op.RHS.first, "sub.r");
565     assert(Op.LHS.second && Op.RHS.second &&
566            "Both operands of integer complex operators must be complex!");
567     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
568   }
569   return ComplexPairTy(ResR, ResI);
570 }
571 
572 /// \brief Emit a libcall for a binary operation on complex types.
573 ComplexPairTy ComplexExprEmitter::EmitComplexBinOpLibCall(StringRef LibCallName,
574                                                           const BinOpInfo &Op) {
575   CallArgList Args;
576   Args.add(RValue::get(Op.LHS.first),
577            Op.Ty->castAs<ComplexType>()->getElementType());
578   Args.add(RValue::get(Op.LHS.second),
579            Op.Ty->castAs<ComplexType>()->getElementType());
580   Args.add(RValue::get(Op.RHS.first),
581            Op.Ty->castAs<ComplexType>()->getElementType());
582   Args.add(RValue::get(Op.RHS.second),
583            Op.Ty->castAs<ComplexType>()->getElementType());
584 
585   // We *must* use the full CG function call building logic here because the
586   // complex type has special ABI handling. We also should not forget about
587   // special calling convention which may be used for compiler builtins.
588 
589   // We create a function qualified type to state that this call does not have
590   // any exceptions.
591   FunctionProtoType::ExtProtoInfo EPI;
592   EPI = EPI.withExceptionSpec(
593       FunctionProtoType::ExceptionSpecInfo(EST_BasicNoexcept));
594   SmallVector<QualType, 4> ArgsQTys(
595       4, Op.Ty->castAs<ComplexType>()->getElementType());
596   QualType FQTy = CGF.getContext().getFunctionType(Op.Ty, ArgsQTys, EPI);
597   const CGFunctionInfo &FuncInfo = CGF.CGM.getTypes().arrangeFreeFunctionCall(
598       Args, cast<FunctionType>(FQTy.getTypePtr()), false);
599 
600   llvm::FunctionType *FTy = CGF.CGM.getTypes().GetFunctionType(FuncInfo);
601   llvm::Constant *Func = CGF.CGM.CreateBuiltinFunction(FTy, LibCallName);
602   CGCallee Callee = CGCallee::forDirect(Func, FQTy->getAs<FunctionProtoType>());
603 
604   llvm::Instruction *Call;
605   RValue Res = CGF.EmitCall(FuncInfo, Callee, ReturnValueSlot(), Args, &Call);
606   cast<llvm::CallInst>(Call)->setCallingConv(CGF.CGM.getBuiltinCC());
607   return Res.getComplexVal();
608 }
609 
610 /// \brief Lookup the libcall name for a given floating point type complex
611 /// multiply.
612 static StringRef getComplexMultiplyLibCallName(llvm::Type *Ty) {
613   switch (Ty->getTypeID()) {
614   default:
615     llvm_unreachable("Unsupported floating point type!");
616   case llvm::Type::HalfTyID:
617     return "__mulhc3";
618   case llvm::Type::FloatTyID:
619     return "__mulsc3";
620   case llvm::Type::DoubleTyID:
621     return "__muldc3";
622   case llvm::Type::PPC_FP128TyID:
623     return "__multc3";
624   case llvm::Type::X86_FP80TyID:
625     return "__mulxc3";
626   case llvm::Type::FP128TyID:
627     return "__multc3";
628   }
629 }
630 
631 // See C11 Annex G.5.1 for the semantics of multiplicative operators on complex
632 // typed values.
633 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
634   using llvm::Value;
635   Value *ResR, *ResI;
636   llvm::MDBuilder MDHelper(CGF.getLLVMContext());
637 
638   if (Op.LHS.first->getType()->isFloatingPointTy()) {
639     // The general formulation is:
640     // (a + ib) * (c + id) = (a * c - b * d) + i(a * d + b * c)
641     //
642     // But we can fold away components which would be zero due to a real
643     // operand according to C11 Annex G.5.1p2.
644     // FIXME: C11 also provides for imaginary types which would allow folding
645     // still more of this within the type system.
646 
647     if (Op.LHS.second && Op.RHS.second) {
648       // If both operands are complex, emit the core math directly, and then
649       // test for NaNs. If we find NaNs in the result, we delegate to a libcall
650       // to carefully re-compute the correct infinity representation if
651       // possible. The expectation is that the presence of NaNs here is
652       // *extremely* rare, and so the cost of the libcall is almost irrelevant.
653       // This is good, because the libcall re-computes the core multiplication
654       // exactly the same as we do here and re-tests for NaNs in order to be
655       // a generic complex*complex libcall.
656 
657       // First compute the four products.
658       Value *AC = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul_ac");
659       Value *BD = Builder.CreateFMul(Op.LHS.second, Op.RHS.second, "mul_bd");
660       Value *AD = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul_ad");
661       Value *BC = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul_bc");
662 
663       // The real part is the difference of the first two, the imaginary part is
664       // the sum of the second.
665       ResR = Builder.CreateFSub(AC, BD, "mul_r");
666       ResI = Builder.CreateFAdd(AD, BC, "mul_i");
667 
668       // Emit the test for the real part becoming NaN and create a branch to
669       // handle it. We test for NaN by comparing the number to itself.
670       Value *IsRNaN = Builder.CreateFCmpUNO(ResR, ResR, "isnan_cmp");
671       llvm::BasicBlock *ContBB = CGF.createBasicBlock("complex_mul_cont");
672       llvm::BasicBlock *INaNBB = CGF.createBasicBlock("complex_mul_imag_nan");
673       llvm::Instruction *Branch = Builder.CreateCondBr(IsRNaN, INaNBB, ContBB);
674       llvm::BasicBlock *OrigBB = Branch->getParent();
675 
676       // Give hint that we very much don't expect to see NaNs.
677       // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
678       llvm::MDNode *BrWeight = MDHelper.createBranchWeights(1, (1U << 20) - 1);
679       Branch->setMetadata(llvm::LLVMContext::MD_prof, BrWeight);
680 
681       // Now test the imaginary part and create its branch.
682       CGF.EmitBlock(INaNBB);
683       Value *IsINaN = Builder.CreateFCmpUNO(ResI, ResI, "isnan_cmp");
684       llvm::BasicBlock *LibCallBB = CGF.createBasicBlock("complex_mul_libcall");
685       Branch = Builder.CreateCondBr(IsINaN, LibCallBB, ContBB);
686       Branch->setMetadata(llvm::LLVMContext::MD_prof, BrWeight);
687 
688       // Now emit the libcall on this slowest of the slow paths.
689       CGF.EmitBlock(LibCallBB);
690       Value *LibCallR, *LibCallI;
691       std::tie(LibCallR, LibCallI) = EmitComplexBinOpLibCall(
692           getComplexMultiplyLibCallName(Op.LHS.first->getType()), Op);
693       Builder.CreateBr(ContBB);
694 
695       // Finally continue execution by phi-ing together the different
696       // computation paths.
697       CGF.EmitBlock(ContBB);
698       llvm::PHINode *RealPHI = Builder.CreatePHI(ResR->getType(), 3, "real_mul_phi");
699       RealPHI->addIncoming(ResR, OrigBB);
700       RealPHI->addIncoming(ResR, INaNBB);
701       RealPHI->addIncoming(LibCallR, LibCallBB);
702       llvm::PHINode *ImagPHI = Builder.CreatePHI(ResI->getType(), 3, "imag_mul_phi");
703       ImagPHI->addIncoming(ResI, OrigBB);
704       ImagPHI->addIncoming(ResI, INaNBB);
705       ImagPHI->addIncoming(LibCallI, LibCallBB);
706       return ComplexPairTy(RealPHI, ImagPHI);
707     }
708     assert((Op.LHS.second || Op.RHS.second) &&
709            "At least one operand must be complex!");
710 
711     // If either of the operands is a real rather than a complex, the
712     // imaginary component is ignored when computing the real component of the
713     // result.
714     ResR = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
715 
716     ResI = Op.LHS.second
717                ? Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il")
718                : Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
719   } else {
720     assert(Op.LHS.second && Op.RHS.second &&
721            "Both operands of integer complex operators must be complex!");
722     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
723     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second, "mul.rr");
724     ResR = Builder.CreateSub(ResRl, ResRr, "mul.r");
725 
726     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
727     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
728     ResI = Builder.CreateAdd(ResIl, ResIr, "mul.i");
729   }
730   return ComplexPairTy(ResR, ResI);
731 }
732 
733 // See C11 Annex G.5.1 for the semantics of multiplicative operators on complex
734 // typed values.
735 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
736   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
737   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
738 
739 
740   llvm::Value *DSTr, *DSTi;
741   if (LHSr->getType()->isFloatingPointTy()) {
742     // If we have a complex operand on the RHS, we delegate to a libcall to
743     // handle all of the complexities and minimize underflow/overflow cases.
744     //
745     // FIXME: We would be able to avoid the libcall in many places if we
746     // supported imaginary types in addition to complex types.
747     if (RHSi) {
748       BinOpInfo LibCallOp = Op;
749       // If LHS was a real, supply a null imaginary part.
750       if (!LHSi)
751         LibCallOp.LHS.second = llvm::Constant::getNullValue(LHSr->getType());
752 
753       StringRef LibCallName;
754       switch (LHSr->getType()->getTypeID()) {
755       default:
756         llvm_unreachable("Unsupported floating point type!");
757       case llvm::Type::HalfTyID:
758         return EmitComplexBinOpLibCall("__divhc3", LibCallOp);
759       case llvm::Type::FloatTyID:
760         return EmitComplexBinOpLibCall("__divsc3", LibCallOp);
761       case llvm::Type::DoubleTyID:
762         return EmitComplexBinOpLibCall("__divdc3", LibCallOp);
763       case llvm::Type::PPC_FP128TyID:
764         return EmitComplexBinOpLibCall("__divtc3", LibCallOp);
765       case llvm::Type::X86_FP80TyID:
766         return EmitComplexBinOpLibCall("__divxc3", LibCallOp);
767       case llvm::Type::FP128TyID:
768         return EmitComplexBinOpLibCall("__divtc3", LibCallOp);
769       }
770     }
771     assert(LHSi && "Can have at most one non-complex operand!");
772 
773     DSTr = Builder.CreateFDiv(LHSr, RHSr);
774     DSTi = Builder.CreateFDiv(LHSi, RHSr);
775   } else {
776     assert(Op.LHS.second && Op.RHS.second &&
777            "Both operands of integer complex operators must be complex!");
778     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
779     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr); // a*c
780     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi); // b*d
781     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2); // ac+bd
782 
783     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr); // c*c
784     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi); // d*d
785     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5); // cc+dd
786 
787     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr); // b*c
788     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi); // a*d
789     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8); // bc-ad
790 
791     if (Op.Ty->castAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
792       DSTr = Builder.CreateUDiv(Tmp3, Tmp6);
793       DSTi = Builder.CreateUDiv(Tmp9, Tmp6);
794     } else {
795       DSTr = Builder.CreateSDiv(Tmp3, Tmp6);
796       DSTi = Builder.CreateSDiv(Tmp9, Tmp6);
797     }
798   }
799 
800   return ComplexPairTy(DSTr, DSTi);
801 }
802 
803 ComplexExprEmitter::BinOpInfo
804 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
805   TestAndClearIgnoreReal();
806   TestAndClearIgnoreImag();
807   BinOpInfo Ops;
808   if (E->getLHS()->getType()->isRealFloatingType())
809     Ops.LHS = ComplexPairTy(CGF.EmitScalarExpr(E->getLHS()), nullptr);
810   else
811     Ops.LHS = Visit(E->getLHS());
812   if (E->getRHS()->getType()->isRealFloatingType())
813     Ops.RHS = ComplexPairTy(CGF.EmitScalarExpr(E->getRHS()), nullptr);
814   else
815     Ops.RHS = Visit(E->getRHS());
816 
817   Ops.Ty = E->getType();
818   return Ops;
819 }
820 
821 
822 LValue ComplexExprEmitter::
823 EmitCompoundAssignLValue(const CompoundAssignOperator *E,
824           ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&),
825                          RValue &Val) {
826   TestAndClearIgnoreReal();
827   TestAndClearIgnoreImag();
828   QualType LHSTy = E->getLHS()->getType();
829   if (const AtomicType *AT = LHSTy->getAs<AtomicType>())
830     LHSTy = AT->getValueType();
831 
832   BinOpInfo OpInfo;
833 
834   // Load the RHS and LHS operands.
835   // __block variables need to have the rhs evaluated first, plus this should
836   // improve codegen a little.
837   OpInfo.Ty = E->getComputationResultType();
838   QualType ComplexElementTy = cast<ComplexType>(OpInfo.Ty)->getElementType();
839 
840   // The RHS should have been converted to the computation type.
841   if (E->getRHS()->getType()->isRealFloatingType()) {
842     assert(
843         CGF.getContext()
844             .hasSameUnqualifiedType(ComplexElementTy, E->getRHS()->getType()));
845     OpInfo.RHS = ComplexPairTy(CGF.EmitScalarExpr(E->getRHS()), nullptr);
846   } else {
847     assert(CGF.getContext()
848                .hasSameUnqualifiedType(OpInfo.Ty, E->getRHS()->getType()));
849     OpInfo.RHS = Visit(E->getRHS());
850   }
851 
852   LValue LHS = CGF.EmitLValue(E->getLHS());
853 
854   // Load from the l-value and convert it.
855   SourceLocation Loc = E->getExprLoc();
856   if (LHSTy->isAnyComplexType()) {
857     ComplexPairTy LHSVal = EmitLoadOfLValue(LHS, Loc);
858     OpInfo.LHS = EmitComplexToComplexCast(LHSVal, LHSTy, OpInfo.Ty, Loc);
859   } else {
860     llvm::Value *LHSVal = CGF.EmitLoadOfScalar(LHS, Loc);
861     // For floating point real operands we can directly pass the scalar form
862     // to the binary operator emission and potentially get more efficient code.
863     if (LHSTy->isRealFloatingType()) {
864       if (!CGF.getContext().hasSameUnqualifiedType(ComplexElementTy, LHSTy))
865         LHSVal = CGF.EmitScalarConversion(LHSVal, LHSTy, ComplexElementTy, Loc);
866       OpInfo.LHS = ComplexPairTy(LHSVal, nullptr);
867     } else {
868       OpInfo.LHS = EmitScalarToComplexCast(LHSVal, LHSTy, OpInfo.Ty, Loc);
869     }
870   }
871 
872   // Expand the binary operator.
873   ComplexPairTy Result = (this->*Func)(OpInfo);
874 
875   // Truncate the result and store it into the LHS lvalue.
876   if (LHSTy->isAnyComplexType()) {
877     ComplexPairTy ResVal =
878         EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy, Loc);
879     EmitStoreOfComplex(ResVal, LHS, /*isInit*/ false);
880     Val = RValue::getComplex(ResVal);
881   } else {
882     llvm::Value *ResVal =
883         CGF.EmitComplexToScalarConversion(Result, OpInfo.Ty, LHSTy, Loc);
884     CGF.EmitStoreOfScalar(ResVal, LHS, /*isInit*/ false);
885     Val = RValue::get(ResVal);
886   }
887 
888   return LHS;
889 }
890 
891 // Compound assignments.
892 ComplexPairTy ComplexExprEmitter::
893 EmitCompoundAssign(const CompoundAssignOperator *E,
894                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
895   RValue Val;
896   LValue LV = EmitCompoundAssignLValue(E, Func, Val);
897 
898   // The result of an assignment in C is the assigned r-value.
899   if (!CGF.getLangOpts().CPlusPlus)
900     return Val.getComplexVal();
901 
902   // If the lvalue is non-volatile, return the computed value of the assignment.
903   if (!LV.isVolatileQualified())
904     return Val.getComplexVal();
905 
906   return EmitLoadOfLValue(LV, E->getExprLoc());
907 }
908 
909 LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
910                                                ComplexPairTy &Val) {
911   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
912                                                  E->getRHS()->getType()) &&
913          "Invalid assignment");
914   TestAndClearIgnoreReal();
915   TestAndClearIgnoreImag();
916 
917   // Emit the RHS.  __block variables need the RHS evaluated first.
918   Val = Visit(E->getRHS());
919 
920   // Compute the address to store into.
921   LValue LHS = CGF.EmitLValue(E->getLHS());
922 
923   // Store the result value into the LHS lvalue.
924   EmitStoreOfComplex(Val, LHS, /*isInit*/ false);
925 
926   return LHS;
927 }
928 
929 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
930   ComplexPairTy Val;
931   LValue LV = EmitBinAssignLValue(E, Val);
932 
933   // The result of an assignment in C is the assigned r-value.
934   if (!CGF.getLangOpts().CPlusPlus)
935     return Val;
936 
937   // If the lvalue is non-volatile, return the computed value of the assignment.
938   if (!LV.isVolatileQualified())
939     return Val;
940 
941   return EmitLoadOfLValue(LV, E->getExprLoc());
942 }
943 
944 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
945   CGF.EmitIgnoredExpr(E->getLHS());
946   return Visit(E->getRHS());
947 }
948 
949 ComplexPairTy ComplexExprEmitter::
950 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
951   TestAndClearIgnoreReal();
952   TestAndClearIgnoreImag();
953   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
954   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
955   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
956 
957   // Bind the common expression if necessary.
958   CodeGenFunction::OpaqueValueMapping binding(CGF, E);
959 
960 
961   CodeGenFunction::ConditionalEvaluation eval(CGF);
962   CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock,
963                            CGF.getProfileCount(E));
964 
965   eval.begin(CGF);
966   CGF.EmitBlock(LHSBlock);
967   CGF.incrementProfileCounter(E);
968   ComplexPairTy LHS = Visit(E->getTrueExpr());
969   LHSBlock = Builder.GetInsertBlock();
970   CGF.EmitBranch(ContBlock);
971   eval.end(CGF);
972 
973   eval.begin(CGF);
974   CGF.EmitBlock(RHSBlock);
975   ComplexPairTy RHS = Visit(E->getFalseExpr());
976   RHSBlock = Builder.GetInsertBlock();
977   CGF.EmitBlock(ContBlock);
978   eval.end(CGF);
979 
980   // Create a PHI node for the real part.
981   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.r");
982   RealPN->addIncoming(LHS.first, LHSBlock);
983   RealPN->addIncoming(RHS.first, RHSBlock);
984 
985   // Create a PHI node for the imaginary part.
986   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.i");
987   ImagPN->addIncoming(LHS.second, LHSBlock);
988   ImagPN->addIncoming(RHS.second, RHSBlock);
989 
990   return ComplexPairTy(RealPN, ImagPN);
991 }
992 
993 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
994   return Visit(E->getChosenSubExpr());
995 }
996 
997 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
998     bool Ignore = TestAndClearIgnoreReal();
999     (void)Ignore;
1000     assert (Ignore == false && "init list ignored");
1001     Ignore = TestAndClearIgnoreImag();
1002     (void)Ignore;
1003     assert (Ignore == false && "init list ignored");
1004 
1005   if (E->getNumInits() == 2) {
1006     llvm::Value *Real = CGF.EmitScalarExpr(E->getInit(0));
1007     llvm::Value *Imag = CGF.EmitScalarExpr(E->getInit(1));
1008     return ComplexPairTy(Real, Imag);
1009   } else if (E->getNumInits() == 1) {
1010     return Visit(E->getInit(0));
1011   }
1012 
1013   // Empty init list intializes to null
1014   assert(E->getNumInits() == 0 && "Unexpected number of inits");
1015   QualType Ty = E->getType()->castAs<ComplexType>()->getElementType();
1016   llvm::Type* LTy = CGF.ConvertType(Ty);
1017   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
1018   return ComplexPairTy(zeroConstant, zeroConstant);
1019 }
1020 
1021 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
1022   Address ArgValue = Address::invalid();
1023   Address ArgPtr = CGF.EmitVAArg(E, ArgValue);
1024 
1025   if (!ArgPtr.isValid()) {
1026     CGF.ErrorUnsupported(E, "complex va_arg expression");
1027     llvm::Type *EltTy =
1028       CGF.ConvertType(E->getType()->castAs<ComplexType>()->getElementType());
1029     llvm::Value *U = llvm::UndefValue::get(EltTy);
1030     return ComplexPairTy(U, U);
1031   }
1032 
1033   return EmitLoadOfLValue(CGF.MakeAddrLValue(ArgPtr, E->getType()),
1034                           E->getExprLoc());
1035 }
1036 
1037 //===----------------------------------------------------------------------===//
1038 //                         Entry Point into this File
1039 //===----------------------------------------------------------------------===//
1040 
1041 /// EmitComplexExpr - Emit the computation of the specified expression of
1042 /// complex type, ignoring the result.
1043 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
1044                                                bool IgnoreImag) {
1045   assert(E && getComplexType(E->getType()) &&
1046          "Invalid complex expression to emit");
1047 
1048   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag)
1049       .Visit(const_cast<Expr *>(E));
1050 }
1051 
1052 void CodeGenFunction::EmitComplexExprIntoLValue(const Expr *E, LValue dest,
1053                                                 bool isInit) {
1054   assert(E && getComplexType(E->getType()) &&
1055          "Invalid complex expression to emit");
1056   ComplexExprEmitter Emitter(*this);
1057   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
1058   Emitter.EmitStoreOfComplex(Val, dest, isInit);
1059 }
1060 
1061 /// EmitStoreOfComplex - Store a complex number into the specified l-value.
1062 void CodeGenFunction::EmitStoreOfComplex(ComplexPairTy V, LValue dest,
1063                                          bool isInit) {
1064   ComplexExprEmitter(*this).EmitStoreOfComplex(V, dest, isInit);
1065 }
1066 
1067 /// EmitLoadOfComplex - Load a complex number from the specified address.
1068 ComplexPairTy CodeGenFunction::EmitLoadOfComplex(LValue src,
1069                                                  SourceLocation loc) {
1070   return ComplexExprEmitter(*this).EmitLoadOfLValue(src, loc);
1071 }
1072 
1073 LValue CodeGenFunction::EmitComplexAssignmentLValue(const BinaryOperator *E) {
1074   assert(E->getOpcode() == BO_Assign);
1075   ComplexPairTy Val; // ignored
1076   return ComplexExprEmitter(*this).EmitBinAssignLValue(E, Val);
1077 }
1078 
1079 typedef ComplexPairTy (ComplexExprEmitter::*CompoundFunc)(
1080     const ComplexExprEmitter::BinOpInfo &);
1081 
1082 static CompoundFunc getComplexOp(BinaryOperatorKind Op) {
1083   switch (Op) {
1084   case BO_MulAssign: return &ComplexExprEmitter::EmitBinMul;
1085   case BO_DivAssign: return &ComplexExprEmitter::EmitBinDiv;
1086   case BO_SubAssign: return &ComplexExprEmitter::EmitBinSub;
1087   case BO_AddAssign: return &ComplexExprEmitter::EmitBinAdd;
1088   default:
1089     llvm_unreachable("unexpected complex compound assignment");
1090   }
1091 }
1092 
1093 LValue CodeGenFunction::
1094 EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E) {
1095   CompoundFunc Op = getComplexOp(E->getOpcode());
1096   RValue Val;
1097   return ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
1098 }
1099 
1100 LValue CodeGenFunction::
1101 EmitScalarCompoundAssignWithComplex(const CompoundAssignOperator *E,
1102                                     llvm::Value *&Result) {
1103   CompoundFunc Op = getComplexOp(E->getOpcode());
1104   RValue Val;
1105   LValue Ret = ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
1106   Result = Val.getScalarVal();
1107   return Ret;
1108 }
1109