1 //===--- CGExprComplex.cpp - Emit LLVM Code for Complex Exprs -------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This contains code to emit Expr nodes with complex types as LLVM code.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "CodeGenFunction.h"
15 #include "CodeGenModule.h"
16 #include "clang/AST/ASTContext.h"
17 #include "clang/AST/StmtVisitor.h"
18 #include "llvm/ADT/STLExtras.h"
19 #include "llvm/ADT/SmallString.h"
20 #include "llvm/IR/Constants.h"
21 #include "llvm/IR/Function.h"
22 #include "llvm/IR/Instructions.h"
23 #include "llvm/IR/MDBuilder.h"
24 #include "llvm/IR/Metadata.h"
25 #include <algorithm>
26 using namespace clang;
27 using namespace CodeGen;
28 
29 //===----------------------------------------------------------------------===//
30 //                        Complex Expression Emitter
31 //===----------------------------------------------------------------------===//
32 
33 typedef CodeGenFunction::ComplexPairTy ComplexPairTy;
34 
35 /// Return the complex type that we are meant to emit.
36 static const ComplexType *getComplexType(QualType type) {
37   type = type.getCanonicalType();
38   if (const ComplexType *comp = dyn_cast<ComplexType>(type)) {
39     return comp;
40   } else {
41     return cast<ComplexType>(cast<AtomicType>(type)->getValueType());
42   }
43 }
44 
45 namespace  {
46 class ComplexExprEmitter
47   : public StmtVisitor<ComplexExprEmitter, ComplexPairTy> {
48   CodeGenFunction &CGF;
49   CGBuilderTy &Builder;
50   bool IgnoreReal;
51   bool IgnoreImag;
52 public:
53   ComplexExprEmitter(CodeGenFunction &cgf, bool ir=false, bool ii=false)
54     : CGF(cgf), Builder(CGF.Builder), IgnoreReal(ir), IgnoreImag(ii) {
55   }
56 
57 
58   //===--------------------------------------------------------------------===//
59   //                               Utilities
60   //===--------------------------------------------------------------------===//
61 
62   bool TestAndClearIgnoreReal() {
63     bool I = IgnoreReal;
64     IgnoreReal = false;
65     return I;
66   }
67   bool TestAndClearIgnoreImag() {
68     bool I = IgnoreImag;
69     IgnoreImag = false;
70     return I;
71   }
72 
73   /// EmitLoadOfLValue - Given an expression with complex type that represents a
74   /// value l-value, this method emits the address of the l-value, then loads
75   /// and returns the result.
76   ComplexPairTy EmitLoadOfLValue(const Expr *E) {
77     return EmitLoadOfLValue(CGF.EmitLValue(E), E->getExprLoc());
78   }
79 
80   ComplexPairTy EmitLoadOfLValue(LValue LV, SourceLocation Loc);
81 
82   /// EmitStoreOfComplex - Store the specified real/imag parts into the
83   /// specified value pointer.
84   void EmitStoreOfComplex(ComplexPairTy Val, LValue LV, bool isInit);
85 
86   /// Emit a cast from complex value Val to DestType.
87   ComplexPairTy EmitComplexToComplexCast(ComplexPairTy Val, QualType SrcType,
88                                          QualType DestType, SourceLocation Loc);
89   /// Emit a cast from scalar value Val to DestType.
90   ComplexPairTy EmitScalarToComplexCast(llvm::Value *Val, QualType SrcType,
91                                         QualType DestType, SourceLocation Loc);
92 
93   //===--------------------------------------------------------------------===//
94   //                            Visitor Methods
95   //===--------------------------------------------------------------------===//
96 
97   ComplexPairTy Visit(Expr *E) {
98     ApplyDebugLocation DL(CGF, E);
99     return StmtVisitor<ComplexExprEmitter, ComplexPairTy>::Visit(E);
100   }
101 
102   ComplexPairTy VisitStmt(Stmt *S) {
103     S->dump(CGF.getContext().getSourceManager());
104     llvm_unreachable("Stmt can't have complex result type!");
105   }
106   ComplexPairTy VisitExpr(Expr *S);
107   ComplexPairTy VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr());}
108   ComplexPairTy VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
109     return Visit(GE->getResultExpr());
110   }
111   ComplexPairTy VisitImaginaryLiteral(const ImaginaryLiteral *IL);
112   ComplexPairTy
113   VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *PE) {
114     return Visit(PE->getReplacement());
115   }
116 
117   // l-values.
118   ComplexPairTy VisitDeclRefExpr(DeclRefExpr *E) {
119     if (CodeGenFunction::ConstantEmission result = CGF.tryEmitAsConstant(E)) {
120       if (result.isReference())
121         return EmitLoadOfLValue(result.getReferenceLValue(CGF, E),
122                                 E->getExprLoc());
123 
124       llvm::Constant *pair = result.getValue();
125       return ComplexPairTy(pair->getAggregateElement(0U),
126                            pair->getAggregateElement(1U));
127     }
128     return EmitLoadOfLValue(E);
129   }
130   ComplexPairTy VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
131     return EmitLoadOfLValue(E);
132   }
133   ComplexPairTy VisitObjCMessageExpr(ObjCMessageExpr *E) {
134     return CGF.EmitObjCMessageExpr(E).getComplexVal();
135   }
136   ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
137   ComplexPairTy VisitMemberExpr(const Expr *E) { return EmitLoadOfLValue(E); }
138   ComplexPairTy VisitOpaqueValueExpr(OpaqueValueExpr *E) {
139     if (E->isGLValue())
140       return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E), E->getExprLoc());
141     return CGF.getOpaqueRValueMapping(E).getComplexVal();
142   }
143 
144   ComplexPairTy VisitPseudoObjectExpr(PseudoObjectExpr *E) {
145     return CGF.EmitPseudoObjectRValue(E).getComplexVal();
146   }
147 
148   // FIXME: CompoundLiteralExpr
149 
150   ComplexPairTy EmitCast(CastKind CK, Expr *Op, QualType DestTy);
151   ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
152     // Unlike for scalars, we don't have to worry about function->ptr demotion
153     // here.
154     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
155   }
156   ComplexPairTy VisitCastExpr(CastExpr *E) {
157     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
158   }
159   ComplexPairTy VisitCallExpr(const CallExpr *E);
160   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
161 
162   // Operators.
163   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
164                                    bool isInc, bool isPre) {
165     LValue LV = CGF.EmitLValue(E->getSubExpr());
166     return CGF.EmitComplexPrePostIncDec(E, LV, isInc, isPre);
167   }
168   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
169     return VisitPrePostIncDec(E, false, false);
170   }
171   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
172     return VisitPrePostIncDec(E, true, false);
173   }
174   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
175     return VisitPrePostIncDec(E, false, true);
176   }
177   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
178     return VisitPrePostIncDec(E, true, true);
179   }
180   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
181   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
182     TestAndClearIgnoreReal();
183     TestAndClearIgnoreImag();
184     return Visit(E->getSubExpr());
185   }
186   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
187   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
188   // LNot,Real,Imag never return complex.
189   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
190     return Visit(E->getSubExpr());
191   }
192   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
193     return Visit(DAE->getExpr());
194   }
195   ComplexPairTy VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
196     CodeGenFunction::CXXDefaultInitExprScope Scope(CGF);
197     return Visit(DIE->getExpr());
198   }
199   ComplexPairTy VisitExprWithCleanups(ExprWithCleanups *E) {
200     CGF.enterFullExpression(E);
201     CodeGenFunction::RunCleanupsScope Scope(CGF);
202     return Visit(E->getSubExpr());
203   }
204   ComplexPairTy VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
205     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
206     QualType Elem = E->getType()->castAs<ComplexType>()->getElementType();
207     llvm::Constant *Null = llvm::Constant::getNullValue(CGF.ConvertType(Elem));
208     return ComplexPairTy(Null, Null);
209   }
210   ComplexPairTy VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
211     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
212     QualType Elem = E->getType()->castAs<ComplexType>()->getElementType();
213     llvm::Constant *Null =
214                        llvm::Constant::getNullValue(CGF.ConvertType(Elem));
215     return ComplexPairTy(Null, Null);
216   }
217 
218   struct BinOpInfo {
219     ComplexPairTy LHS;
220     ComplexPairTy RHS;
221     QualType Ty;  // Computation Type.
222   };
223 
224   BinOpInfo EmitBinOps(const BinaryOperator *E);
225   LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
226                                   ComplexPairTy (ComplexExprEmitter::*Func)
227                                   (const BinOpInfo &),
228                                   RValue &Val);
229   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
230                                    ComplexPairTy (ComplexExprEmitter::*Func)
231                                    (const BinOpInfo &));
232 
233   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
234   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
235   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
236   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
237 
238   ComplexPairTy EmitComplexBinOpLibCall(StringRef LibCallName,
239                                         const BinOpInfo &Op);
240 
241   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
242     return EmitBinAdd(EmitBinOps(E));
243   }
244   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
245     return EmitBinSub(EmitBinOps(E));
246   }
247   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
248     return EmitBinMul(EmitBinOps(E));
249   }
250   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
251     return EmitBinDiv(EmitBinOps(E));
252   }
253 
254   // Compound assignments.
255   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
256     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
257   }
258   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
259     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
260   }
261   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
262     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
263   }
264   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
265     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
266   }
267 
268   // GCC rejects rem/and/or/xor for integer complex.
269   // Logical and/or always return int, never complex.
270 
271   // No comparisons produce a complex result.
272 
273   LValue EmitBinAssignLValue(const BinaryOperator *E,
274                              ComplexPairTy &Val);
275   ComplexPairTy VisitBinAssign     (const BinaryOperator *E);
276   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
277 
278 
279   ComplexPairTy
280   VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
281   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
282 
283   ComplexPairTy VisitInitListExpr(InitListExpr *E);
284 
285   ComplexPairTy VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
286     return EmitLoadOfLValue(E);
287   }
288 
289   ComplexPairTy VisitVAArgExpr(VAArgExpr *E);
290 
291   ComplexPairTy VisitAtomicExpr(AtomicExpr *E) {
292     return CGF.EmitAtomicExpr(E).getComplexVal();
293   }
294 };
295 }  // end anonymous namespace.
296 
297 //===----------------------------------------------------------------------===//
298 //                                Utilities
299 //===----------------------------------------------------------------------===//
300 
301 Address CodeGenFunction::emitAddrOfRealComponent(Address addr,
302                                                  QualType complexType) {
303   CharUnits offset = CharUnits::Zero();
304   return Builder.CreateStructGEP(addr, 0, offset, addr.getName() + ".realp");
305 }
306 
307 Address CodeGenFunction::emitAddrOfImagComponent(Address addr,
308                                                  QualType complexType) {
309   QualType eltType = complexType->castAs<ComplexType>()->getElementType();
310   CharUnits offset = getContext().getTypeSizeInChars(eltType);
311   return Builder.CreateStructGEP(addr, 1, offset, addr.getName() + ".imagp");
312 }
313 
314 /// EmitLoadOfLValue - Given an RValue reference for a complex, emit code to
315 /// load the real and imaginary pieces, returning them as Real/Imag.
316 ComplexPairTy ComplexExprEmitter::EmitLoadOfLValue(LValue lvalue,
317                                                    SourceLocation loc) {
318   assert(lvalue.isSimple() && "non-simple complex l-value?");
319   if (lvalue.getType()->isAtomicType())
320     return CGF.EmitAtomicLoad(lvalue, loc).getComplexVal();
321 
322   Address SrcPtr = lvalue.getAddress();
323   bool isVolatile = lvalue.isVolatileQualified();
324 
325   llvm::Value *Real = nullptr, *Imag = nullptr;
326 
327   if (!IgnoreReal || isVolatile) {
328     Address RealP = CGF.emitAddrOfRealComponent(SrcPtr, lvalue.getType());
329     Real = Builder.CreateLoad(RealP, isVolatile, SrcPtr.getName() + ".real");
330   }
331 
332   if (!IgnoreImag || isVolatile) {
333     Address ImagP = CGF.emitAddrOfImagComponent(SrcPtr, lvalue.getType());
334     Imag = Builder.CreateLoad(ImagP, isVolatile, SrcPtr.getName() + ".imag");
335   }
336 
337   return ComplexPairTy(Real, Imag);
338 }
339 
340 /// EmitStoreOfComplex - Store the specified real/imag parts into the
341 /// specified value pointer.
342 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, LValue lvalue,
343                                             bool isInit) {
344   if (lvalue.getType()->isAtomicType() ||
345       (!isInit && CGF.LValueIsSuitableForInlineAtomic(lvalue)))
346     return CGF.EmitAtomicStore(RValue::getComplex(Val), lvalue, isInit);
347 
348   Address Ptr = lvalue.getAddress();
349   Address RealPtr = CGF.emitAddrOfRealComponent(Ptr, lvalue.getType());
350   Address ImagPtr = CGF.emitAddrOfImagComponent(Ptr, lvalue.getType());
351 
352   Builder.CreateStore(Val.first, RealPtr, lvalue.isVolatileQualified());
353   Builder.CreateStore(Val.second, ImagPtr, lvalue.isVolatileQualified());
354 }
355 
356 
357 
358 //===----------------------------------------------------------------------===//
359 //                            Visitor Methods
360 //===----------------------------------------------------------------------===//
361 
362 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
363   CGF.ErrorUnsupported(E, "complex expression");
364   llvm::Type *EltTy =
365     CGF.ConvertType(getComplexType(E->getType())->getElementType());
366   llvm::Value *U = llvm::UndefValue::get(EltTy);
367   return ComplexPairTy(U, U);
368 }
369 
370 ComplexPairTy ComplexExprEmitter::
371 VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
372   llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
373   return ComplexPairTy(llvm::Constant::getNullValue(Imag->getType()), Imag);
374 }
375 
376 
377 ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
378   if (E->getCallReturnType(CGF.getContext())->isReferenceType())
379     return EmitLoadOfLValue(E);
380 
381   return CGF.EmitCallExpr(E).getComplexVal();
382 }
383 
384 ComplexPairTy ComplexExprEmitter::VisitStmtExpr(const StmtExpr *E) {
385   CodeGenFunction::StmtExprEvaluation eval(CGF);
386   Address RetAlloca = CGF.EmitCompoundStmt(*E->getSubStmt(), true);
387   assert(RetAlloca.isValid() && "Expected complex return value");
388   return EmitLoadOfLValue(CGF.MakeAddrLValue(RetAlloca, E->getType()),
389                           E->getExprLoc());
390 }
391 
392 /// Emit a cast from complex value Val to DestType.
393 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
394                                                            QualType SrcType,
395                                                            QualType DestType,
396                                                            SourceLocation Loc) {
397   // Get the src/dest element type.
398   SrcType = SrcType->castAs<ComplexType>()->getElementType();
399   DestType = DestType->castAs<ComplexType>()->getElementType();
400 
401   // C99 6.3.1.6: When a value of complex type is converted to another
402   // complex type, both the real and imaginary parts follow the conversion
403   // rules for the corresponding real types.
404   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType, Loc);
405   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType, Loc);
406   return Val;
407 }
408 
409 ComplexPairTy ComplexExprEmitter::EmitScalarToComplexCast(llvm::Value *Val,
410                                                           QualType SrcType,
411                                                           QualType DestType,
412                                                           SourceLocation Loc) {
413   // Convert the input element to the element type of the complex.
414   DestType = DestType->castAs<ComplexType>()->getElementType();
415   Val = CGF.EmitScalarConversion(Val, SrcType, DestType, Loc);
416 
417   // Return (realval, 0).
418   return ComplexPairTy(Val, llvm::Constant::getNullValue(Val->getType()));
419 }
420 
421 ComplexPairTy ComplexExprEmitter::EmitCast(CastKind CK, Expr *Op,
422                                            QualType DestTy) {
423   switch (CK) {
424   case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!");
425 
426   // Atomic to non-atomic casts may be more than a no-op for some platforms and
427   // for some types.
428   case CK_AtomicToNonAtomic:
429   case CK_NonAtomicToAtomic:
430   case CK_NoOp:
431   case CK_LValueToRValue:
432   case CK_UserDefinedConversion:
433     return Visit(Op);
434 
435   case CK_LValueBitCast: {
436     LValue origLV = CGF.EmitLValue(Op);
437     Address V = origLV.getAddress();
438     V = Builder.CreateElementBitCast(V, CGF.ConvertType(DestTy));
439     return EmitLoadOfLValue(CGF.MakeAddrLValue(V, DestTy), Op->getExprLoc());
440   }
441 
442   case CK_BitCast:
443   case CK_BaseToDerived:
444   case CK_DerivedToBase:
445   case CK_UncheckedDerivedToBase:
446   case CK_Dynamic:
447   case CK_ToUnion:
448   case CK_ArrayToPointerDecay:
449   case CK_FunctionToPointerDecay:
450   case CK_NullToPointer:
451   case CK_NullToMemberPointer:
452   case CK_BaseToDerivedMemberPointer:
453   case CK_DerivedToBaseMemberPointer:
454   case CK_MemberPointerToBoolean:
455   case CK_ReinterpretMemberPointer:
456   case CK_ConstructorConversion:
457   case CK_IntegralToPointer:
458   case CK_PointerToIntegral:
459   case CK_PointerToBoolean:
460   case CK_ToVoid:
461   case CK_VectorSplat:
462   case CK_IntegralCast:
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     llvm_unreachable("invalid cast kind for complex value");
485 
486   case CK_FloatingRealToComplex:
487   case CK_IntegralRealToComplex:
488     return EmitScalarToComplexCast(CGF.EmitScalarExpr(Op), Op->getType(),
489                                    DestTy, Op->getExprLoc());
490 
491   case CK_FloatingComplexCast:
492   case CK_FloatingComplexToIntegralComplex:
493   case CK_IntegralComplexCast:
494   case CK_IntegralComplexToFloatingComplex:
495     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy,
496                                     Op->getExprLoc());
497   }
498 
499   llvm_unreachable("unknown cast resulting in complex value");
500 }
501 
502 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
503   TestAndClearIgnoreReal();
504   TestAndClearIgnoreImag();
505   ComplexPairTy Op = Visit(E->getSubExpr());
506 
507   llvm::Value *ResR, *ResI;
508   if (Op.first->getType()->isFloatingPointTy()) {
509     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
510     ResI = Builder.CreateFNeg(Op.second, "neg.i");
511   } else {
512     ResR = Builder.CreateNeg(Op.first,  "neg.r");
513     ResI = Builder.CreateNeg(Op.second, "neg.i");
514   }
515   return ComplexPairTy(ResR, ResI);
516 }
517 
518 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
519   TestAndClearIgnoreReal();
520   TestAndClearIgnoreImag();
521   // ~(a+ib) = a + i*-b
522   ComplexPairTy Op = Visit(E->getSubExpr());
523   llvm::Value *ResI;
524   if (Op.second->getType()->isFloatingPointTy())
525     ResI = Builder.CreateFNeg(Op.second, "conj.i");
526   else
527     ResI = Builder.CreateNeg(Op.second, "conj.i");
528 
529   return ComplexPairTy(Op.first, ResI);
530 }
531 
532 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
533   llvm::Value *ResR, *ResI;
534 
535   if (Op.LHS.first->getType()->isFloatingPointTy()) {
536     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
537     if (Op.LHS.second && Op.RHS.second)
538       ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
539     else
540       ResI = Op.LHS.second ? Op.LHS.second : Op.RHS.second;
541     assert(ResI && "Only one operand may be real!");
542   } else {
543     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
544     assert(Op.LHS.second && Op.RHS.second &&
545            "Both operands of integer complex operators must be complex!");
546     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
547   }
548   return ComplexPairTy(ResR, ResI);
549 }
550 
551 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
552   llvm::Value *ResR, *ResI;
553   if (Op.LHS.first->getType()->isFloatingPointTy()) {
554     ResR = Builder.CreateFSub(Op.LHS.first, Op.RHS.first, "sub.r");
555     if (Op.LHS.second && Op.RHS.second)
556       ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
557     else
558       ResI = Op.LHS.second ? Op.LHS.second
559                            : Builder.CreateFNeg(Op.RHS.second, "sub.i");
560     assert(ResI && "Only one operand may be real!");
561   } else {
562     ResR = Builder.CreateSub(Op.LHS.first, Op.RHS.first, "sub.r");
563     assert(Op.LHS.second && Op.RHS.second &&
564            "Both operands of integer complex operators must be complex!");
565     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
566   }
567   return ComplexPairTy(ResR, ResI);
568 }
569 
570 /// \brief Emit a libcall for a binary operation on complex types.
571 ComplexPairTy ComplexExprEmitter::EmitComplexBinOpLibCall(StringRef LibCallName,
572                                                           const BinOpInfo &Op) {
573   CallArgList Args;
574   Args.add(RValue::get(Op.LHS.first),
575            Op.Ty->castAs<ComplexType>()->getElementType());
576   Args.add(RValue::get(Op.LHS.second),
577            Op.Ty->castAs<ComplexType>()->getElementType());
578   Args.add(RValue::get(Op.RHS.first),
579            Op.Ty->castAs<ComplexType>()->getElementType());
580   Args.add(RValue::get(Op.RHS.second),
581            Op.Ty->castAs<ComplexType>()->getElementType());
582 
583   // We *must* use the full CG function call building logic here because the
584   // complex type has special ABI handling. We also should not forget about
585   // special calling convention which may be used for compiler builtins.
586   const CGFunctionInfo &FuncInfo =
587     CGF.CGM.getTypes().arrangeFreeFunctionCall(
588       Op.Ty, Args, FunctionType::ExtInfo(/* No CC here - will be added later */),
589       RequiredArgs::All);
590   llvm::FunctionType *FTy = CGF.CGM.getTypes().GetFunctionType(FuncInfo);
591   llvm::Constant *Func = CGF.CGM.CreateBuiltinFunction(FTy, LibCallName);
592   llvm::Instruction *Call;
593 
594   RValue Res = CGF.EmitCall(FuncInfo, Func, ReturnValueSlot(), Args,
595                             nullptr, &Call);
596   cast<llvm::CallInst>(Call)->setCallingConv(CGF.CGM.getBuiltinCC());
597   cast<llvm::CallInst>(Call)->setDoesNotThrow();
598 
599   return Res.getComplexVal();
600 }
601 
602 /// \brief Lookup the libcall name for a given floating point type complex
603 /// multiply.
604 static StringRef getComplexMultiplyLibCallName(llvm::Type *Ty) {
605   switch (Ty->getTypeID()) {
606   default:
607     llvm_unreachable("Unsupported floating point type!");
608   case llvm::Type::HalfTyID:
609     return "__mulhc3";
610   case llvm::Type::FloatTyID:
611     return "__mulsc3";
612   case llvm::Type::DoubleTyID:
613     return "__muldc3";
614   case llvm::Type::PPC_FP128TyID:
615     return "__multc3";
616   case llvm::Type::X86_FP80TyID:
617     return "__mulxc3";
618   case llvm::Type::FP128TyID:
619     return "__multc3";
620   }
621 }
622 
623 // See C11 Annex G.5.1 for the semantics of multiplicative operators on complex
624 // typed values.
625 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
626   using llvm::Value;
627   Value *ResR, *ResI;
628   llvm::MDBuilder MDHelper(CGF.getLLVMContext());
629 
630   if (Op.LHS.first->getType()->isFloatingPointTy()) {
631     // The general formulation is:
632     // (a + ib) * (c + id) = (a * c - b * d) + i(a * d + b * c)
633     //
634     // But we can fold away components which would be zero due to a real
635     // operand according to C11 Annex G.5.1p2.
636     // FIXME: C11 also provides for imaginary types which would allow folding
637     // still more of this within the type system.
638 
639     if (Op.LHS.second && Op.RHS.second) {
640       // If both operands are complex, emit the core math directly, and then
641       // test for NaNs. If we find NaNs in the result, we delegate to a libcall
642       // to carefully re-compute the correct infinity representation if
643       // possible. The expectation is that the presence of NaNs here is
644       // *extremely* rare, and so the cost of the libcall is almost irrelevant.
645       // This is good, because the libcall re-computes the core multiplication
646       // exactly the same as we do here and re-tests for NaNs in order to be
647       // a generic complex*complex libcall.
648 
649       // First compute the four products.
650       Value *AC = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul_ac");
651       Value *BD = Builder.CreateFMul(Op.LHS.second, Op.RHS.second, "mul_bd");
652       Value *AD = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul_ad");
653       Value *BC = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul_bc");
654 
655       // The real part is the difference of the first two, the imaginary part is
656       // the sum of the second.
657       ResR = Builder.CreateFSub(AC, BD, "mul_r");
658       ResI = Builder.CreateFAdd(AD, BC, "mul_i");
659 
660       // Emit the test for the real part becoming NaN and create a branch to
661       // handle it. We test for NaN by comparing the number to itself.
662       Value *IsRNaN = Builder.CreateFCmpUNO(ResR, ResR, "isnan_cmp");
663       llvm::BasicBlock *ContBB = CGF.createBasicBlock("complex_mul_cont");
664       llvm::BasicBlock *INaNBB = CGF.createBasicBlock("complex_mul_imag_nan");
665       llvm::Instruction *Branch = Builder.CreateCondBr(IsRNaN, INaNBB, ContBB);
666       llvm::BasicBlock *OrigBB = Branch->getParent();
667 
668       // Give hint that we very much don't expect to see NaNs.
669       // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
670       llvm::MDNode *BrWeight = MDHelper.createBranchWeights(1, (1U << 20) - 1);
671       Branch->setMetadata(llvm::LLVMContext::MD_prof, BrWeight);
672 
673       // Now test the imaginary part and create its branch.
674       CGF.EmitBlock(INaNBB);
675       Value *IsINaN = Builder.CreateFCmpUNO(ResI, ResI, "isnan_cmp");
676       llvm::BasicBlock *LibCallBB = CGF.createBasicBlock("complex_mul_libcall");
677       Branch = Builder.CreateCondBr(IsINaN, LibCallBB, ContBB);
678       Branch->setMetadata(llvm::LLVMContext::MD_prof, BrWeight);
679 
680       // Now emit the libcall on this slowest of the slow paths.
681       CGF.EmitBlock(LibCallBB);
682       Value *LibCallR, *LibCallI;
683       std::tie(LibCallR, LibCallI) = EmitComplexBinOpLibCall(
684           getComplexMultiplyLibCallName(Op.LHS.first->getType()), Op);
685       Builder.CreateBr(ContBB);
686 
687       // Finally continue execution by phi-ing together the different
688       // computation paths.
689       CGF.EmitBlock(ContBB);
690       llvm::PHINode *RealPHI = Builder.CreatePHI(ResR->getType(), 3, "real_mul_phi");
691       RealPHI->addIncoming(ResR, OrigBB);
692       RealPHI->addIncoming(ResR, INaNBB);
693       RealPHI->addIncoming(LibCallR, LibCallBB);
694       llvm::PHINode *ImagPHI = Builder.CreatePHI(ResI->getType(), 3, "imag_mul_phi");
695       ImagPHI->addIncoming(ResI, OrigBB);
696       ImagPHI->addIncoming(ResI, INaNBB);
697       ImagPHI->addIncoming(LibCallI, LibCallBB);
698       return ComplexPairTy(RealPHI, ImagPHI);
699     }
700     assert((Op.LHS.second || Op.RHS.second) &&
701            "At least one operand must be complex!");
702 
703     // If either of the operands is a real rather than a complex, the
704     // imaginary component is ignored when computing the real component of the
705     // result.
706     ResR = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
707 
708     ResI = Op.LHS.second
709                ? Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il")
710                : Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
711   } else {
712     assert(Op.LHS.second && Op.RHS.second &&
713            "Both operands of integer complex operators must be complex!");
714     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
715     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second, "mul.rr");
716     ResR = Builder.CreateSub(ResRl, ResRr, "mul.r");
717 
718     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
719     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
720     ResI = Builder.CreateAdd(ResIl, ResIr, "mul.i");
721   }
722   return ComplexPairTy(ResR, ResI);
723 }
724 
725 // See C11 Annex G.5.1 for the semantics of multiplicative operators on complex
726 // typed values.
727 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
728   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
729   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
730 
731 
732   llvm::Value *DSTr, *DSTi;
733   if (LHSr->getType()->isFloatingPointTy()) {
734     // If we have a complex operand on the RHS, we delegate to a libcall to
735     // handle all of the complexities and minimize underflow/overflow cases.
736     //
737     // FIXME: We would be able to avoid the libcall in many places if we
738     // supported imaginary types in addition to complex types.
739     if (RHSi) {
740       BinOpInfo LibCallOp = Op;
741       // If LHS was a real, supply a null imaginary part.
742       if (!LHSi)
743         LibCallOp.LHS.second = llvm::Constant::getNullValue(LHSr->getType());
744 
745       StringRef LibCallName;
746       switch (LHSr->getType()->getTypeID()) {
747       default:
748         llvm_unreachable("Unsupported floating point type!");
749       case llvm::Type::HalfTyID:
750         return EmitComplexBinOpLibCall("__divhc3", LibCallOp);
751       case llvm::Type::FloatTyID:
752         return EmitComplexBinOpLibCall("__divsc3", LibCallOp);
753       case llvm::Type::DoubleTyID:
754         return EmitComplexBinOpLibCall("__divdc3", LibCallOp);
755       case llvm::Type::PPC_FP128TyID:
756         return EmitComplexBinOpLibCall("__divtc3", LibCallOp);
757       case llvm::Type::X86_FP80TyID:
758         return EmitComplexBinOpLibCall("__divxc3", LibCallOp);
759       case llvm::Type::FP128TyID:
760         return EmitComplexBinOpLibCall("__divtc3", LibCallOp);
761       }
762     }
763     assert(LHSi && "Can have at most one non-complex operand!");
764 
765     DSTr = Builder.CreateFDiv(LHSr, RHSr);
766     DSTi = Builder.CreateFDiv(LHSi, RHSr);
767   } else {
768     assert(Op.LHS.second && Op.RHS.second &&
769            "Both operands of integer complex operators must be complex!");
770     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
771     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr); // a*c
772     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi); // b*d
773     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2); // ac+bd
774 
775     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr); // c*c
776     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi); // d*d
777     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5); // cc+dd
778 
779     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr); // b*c
780     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi); // a*d
781     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8); // bc-ad
782 
783     if (Op.Ty->castAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
784       DSTr = Builder.CreateUDiv(Tmp3, Tmp6);
785       DSTi = Builder.CreateUDiv(Tmp9, Tmp6);
786     } else {
787       DSTr = Builder.CreateSDiv(Tmp3, Tmp6);
788       DSTi = Builder.CreateSDiv(Tmp9, Tmp6);
789     }
790   }
791 
792   return ComplexPairTy(DSTr, DSTi);
793 }
794 
795 ComplexExprEmitter::BinOpInfo
796 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
797   TestAndClearIgnoreReal();
798   TestAndClearIgnoreImag();
799   BinOpInfo Ops;
800   if (E->getLHS()->getType()->isRealFloatingType())
801     Ops.LHS = ComplexPairTy(CGF.EmitScalarExpr(E->getLHS()), nullptr);
802   else
803     Ops.LHS = Visit(E->getLHS());
804   if (E->getRHS()->getType()->isRealFloatingType())
805     Ops.RHS = ComplexPairTy(CGF.EmitScalarExpr(E->getRHS()), nullptr);
806   else
807     Ops.RHS = Visit(E->getRHS());
808 
809   Ops.Ty = E->getType();
810   return Ops;
811 }
812 
813 
814 LValue ComplexExprEmitter::
815 EmitCompoundAssignLValue(const CompoundAssignOperator *E,
816           ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&),
817                          RValue &Val) {
818   TestAndClearIgnoreReal();
819   TestAndClearIgnoreImag();
820   QualType LHSTy = E->getLHS()->getType();
821   if (const AtomicType *AT = LHSTy->getAs<AtomicType>())
822     LHSTy = AT->getValueType();
823 
824   BinOpInfo OpInfo;
825 
826   // Load the RHS and LHS operands.
827   // __block variables need to have the rhs evaluated first, plus this should
828   // improve codegen a little.
829   OpInfo.Ty = E->getComputationResultType();
830   QualType ComplexElementTy = cast<ComplexType>(OpInfo.Ty)->getElementType();
831 
832   // The RHS should have been converted to the computation type.
833   if (E->getRHS()->getType()->isRealFloatingType()) {
834     assert(
835         CGF.getContext()
836             .hasSameUnqualifiedType(ComplexElementTy, E->getRHS()->getType()));
837     OpInfo.RHS = ComplexPairTy(CGF.EmitScalarExpr(E->getRHS()), nullptr);
838   } else {
839     assert(CGF.getContext()
840                .hasSameUnqualifiedType(OpInfo.Ty, E->getRHS()->getType()));
841     OpInfo.RHS = Visit(E->getRHS());
842   }
843 
844   LValue LHS = CGF.EmitLValue(E->getLHS());
845 
846   // Load from the l-value and convert it.
847   SourceLocation Loc = E->getExprLoc();
848   if (LHSTy->isAnyComplexType()) {
849     ComplexPairTy LHSVal = EmitLoadOfLValue(LHS, Loc);
850     OpInfo.LHS = EmitComplexToComplexCast(LHSVal, LHSTy, OpInfo.Ty, Loc);
851   } else {
852     llvm::Value *LHSVal = CGF.EmitLoadOfScalar(LHS, Loc);
853     // For floating point real operands we can directly pass the scalar form
854     // to the binary operator emission and potentially get more efficient code.
855     if (LHSTy->isRealFloatingType()) {
856       if (!CGF.getContext().hasSameUnqualifiedType(ComplexElementTy, LHSTy))
857         LHSVal = CGF.EmitScalarConversion(LHSVal, LHSTy, ComplexElementTy, Loc);
858       OpInfo.LHS = ComplexPairTy(LHSVal, nullptr);
859     } else {
860       OpInfo.LHS = EmitScalarToComplexCast(LHSVal, LHSTy, OpInfo.Ty, Loc);
861     }
862   }
863 
864   // Expand the binary operator.
865   ComplexPairTy Result = (this->*Func)(OpInfo);
866 
867   // Truncate the result and store it into the LHS lvalue.
868   if (LHSTy->isAnyComplexType()) {
869     ComplexPairTy ResVal =
870         EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy, Loc);
871     EmitStoreOfComplex(ResVal, LHS, /*isInit*/ false);
872     Val = RValue::getComplex(ResVal);
873   } else {
874     llvm::Value *ResVal =
875         CGF.EmitComplexToScalarConversion(Result, OpInfo.Ty, LHSTy, Loc);
876     CGF.EmitStoreOfScalar(ResVal, LHS, /*isInit*/ false);
877     Val = RValue::get(ResVal);
878   }
879 
880   return LHS;
881 }
882 
883 // Compound assignments.
884 ComplexPairTy ComplexExprEmitter::
885 EmitCompoundAssign(const CompoundAssignOperator *E,
886                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
887   RValue Val;
888   LValue LV = EmitCompoundAssignLValue(E, Func, Val);
889 
890   // The result of an assignment in C is the assigned r-value.
891   if (!CGF.getLangOpts().CPlusPlus)
892     return Val.getComplexVal();
893 
894   // If the lvalue is non-volatile, return the computed value of the assignment.
895   if (!LV.isVolatileQualified())
896     return Val.getComplexVal();
897 
898   return EmitLoadOfLValue(LV, E->getExprLoc());
899 }
900 
901 LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
902                                                ComplexPairTy &Val) {
903   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
904                                                  E->getRHS()->getType()) &&
905          "Invalid assignment");
906   TestAndClearIgnoreReal();
907   TestAndClearIgnoreImag();
908 
909   // Emit the RHS.  __block variables need the RHS evaluated first.
910   Val = Visit(E->getRHS());
911 
912   // Compute the address to store into.
913   LValue LHS = CGF.EmitLValue(E->getLHS());
914 
915   // Store the result value into the LHS lvalue.
916   EmitStoreOfComplex(Val, LHS, /*isInit*/ false);
917 
918   return LHS;
919 }
920 
921 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
922   ComplexPairTy Val;
923   LValue LV = EmitBinAssignLValue(E, Val);
924 
925   // The result of an assignment in C is the assigned r-value.
926   if (!CGF.getLangOpts().CPlusPlus)
927     return Val;
928 
929   // If the lvalue is non-volatile, return the computed value of the assignment.
930   if (!LV.isVolatileQualified())
931     return Val;
932 
933   return EmitLoadOfLValue(LV, E->getExprLoc());
934 }
935 
936 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
937   CGF.EmitIgnoredExpr(E->getLHS());
938   return Visit(E->getRHS());
939 }
940 
941 ComplexPairTy ComplexExprEmitter::
942 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
943   TestAndClearIgnoreReal();
944   TestAndClearIgnoreImag();
945   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
946   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
947   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
948 
949   // Bind the common expression if necessary.
950   CodeGenFunction::OpaqueValueMapping binding(CGF, E);
951 
952 
953   CodeGenFunction::ConditionalEvaluation eval(CGF);
954   CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock,
955                            CGF.getProfileCount(E));
956 
957   eval.begin(CGF);
958   CGF.EmitBlock(LHSBlock);
959   CGF.incrementProfileCounter(E);
960   ComplexPairTy LHS = Visit(E->getTrueExpr());
961   LHSBlock = Builder.GetInsertBlock();
962   CGF.EmitBranch(ContBlock);
963   eval.end(CGF);
964 
965   eval.begin(CGF);
966   CGF.EmitBlock(RHSBlock);
967   ComplexPairTy RHS = Visit(E->getFalseExpr());
968   RHSBlock = Builder.GetInsertBlock();
969   CGF.EmitBlock(ContBlock);
970   eval.end(CGF);
971 
972   // Create a PHI node for the real part.
973   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.r");
974   RealPN->addIncoming(LHS.first, LHSBlock);
975   RealPN->addIncoming(RHS.first, RHSBlock);
976 
977   // Create a PHI node for the imaginary part.
978   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.i");
979   ImagPN->addIncoming(LHS.second, LHSBlock);
980   ImagPN->addIncoming(RHS.second, RHSBlock);
981 
982   return ComplexPairTy(RealPN, ImagPN);
983 }
984 
985 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
986   return Visit(E->getChosenSubExpr());
987 }
988 
989 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
990     bool Ignore = TestAndClearIgnoreReal();
991     (void)Ignore;
992     assert (Ignore == false && "init list ignored");
993     Ignore = TestAndClearIgnoreImag();
994     (void)Ignore;
995     assert (Ignore == false && "init list ignored");
996 
997   if (E->getNumInits() == 2) {
998     llvm::Value *Real = CGF.EmitScalarExpr(E->getInit(0));
999     llvm::Value *Imag = CGF.EmitScalarExpr(E->getInit(1));
1000     return ComplexPairTy(Real, Imag);
1001   } else if (E->getNumInits() == 1) {
1002     return Visit(E->getInit(0));
1003   }
1004 
1005   // Empty init list intializes to null
1006   assert(E->getNumInits() == 0 && "Unexpected number of inits");
1007   QualType Ty = E->getType()->castAs<ComplexType>()->getElementType();
1008   llvm::Type* LTy = CGF.ConvertType(Ty);
1009   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
1010   return ComplexPairTy(zeroConstant, zeroConstant);
1011 }
1012 
1013 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
1014   Address ArgValue = Address::invalid();
1015   Address ArgPtr = CGF.EmitVAArg(E, ArgValue);
1016 
1017   if (!ArgPtr.isValid()) {
1018     CGF.ErrorUnsupported(E, "complex va_arg expression");
1019     llvm::Type *EltTy =
1020       CGF.ConvertType(E->getType()->castAs<ComplexType>()->getElementType());
1021     llvm::Value *U = llvm::UndefValue::get(EltTy);
1022     return ComplexPairTy(U, U);
1023   }
1024 
1025   return EmitLoadOfLValue(CGF.MakeAddrLValue(ArgPtr, E->getType()),
1026                           E->getExprLoc());
1027 }
1028 
1029 //===----------------------------------------------------------------------===//
1030 //                         Entry Point into this File
1031 //===----------------------------------------------------------------------===//
1032 
1033 /// EmitComplexExpr - Emit the computation of the specified expression of
1034 /// complex type, ignoring the result.
1035 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
1036                                                bool IgnoreImag) {
1037   assert(E && getComplexType(E->getType()) &&
1038          "Invalid complex expression to emit");
1039 
1040   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag)
1041       .Visit(const_cast<Expr *>(E));
1042 }
1043 
1044 void CodeGenFunction::EmitComplexExprIntoLValue(const Expr *E, LValue dest,
1045                                                 bool isInit) {
1046   assert(E && getComplexType(E->getType()) &&
1047          "Invalid complex expression to emit");
1048   ComplexExprEmitter Emitter(*this);
1049   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
1050   Emitter.EmitStoreOfComplex(Val, dest, isInit);
1051 }
1052 
1053 /// EmitStoreOfComplex - Store a complex number into the specified l-value.
1054 void CodeGenFunction::EmitStoreOfComplex(ComplexPairTy V, LValue dest,
1055                                          bool isInit) {
1056   ComplexExprEmitter(*this).EmitStoreOfComplex(V, dest, isInit);
1057 }
1058 
1059 /// EmitLoadOfComplex - Load a complex number from the specified address.
1060 ComplexPairTy CodeGenFunction::EmitLoadOfComplex(LValue src,
1061                                                  SourceLocation loc) {
1062   return ComplexExprEmitter(*this).EmitLoadOfLValue(src, loc);
1063 }
1064 
1065 LValue CodeGenFunction::EmitComplexAssignmentLValue(const BinaryOperator *E) {
1066   assert(E->getOpcode() == BO_Assign);
1067   ComplexPairTy Val; // ignored
1068   return ComplexExprEmitter(*this).EmitBinAssignLValue(E, Val);
1069 }
1070 
1071 typedef ComplexPairTy (ComplexExprEmitter::*CompoundFunc)(
1072     const ComplexExprEmitter::BinOpInfo &);
1073 
1074 static CompoundFunc getComplexOp(BinaryOperatorKind Op) {
1075   switch (Op) {
1076   case BO_MulAssign: return &ComplexExprEmitter::EmitBinMul;
1077   case BO_DivAssign: return &ComplexExprEmitter::EmitBinDiv;
1078   case BO_SubAssign: return &ComplexExprEmitter::EmitBinSub;
1079   case BO_AddAssign: return &ComplexExprEmitter::EmitBinAdd;
1080   default:
1081     llvm_unreachable("unexpected complex compound assignment");
1082   }
1083 }
1084 
1085 LValue CodeGenFunction::
1086 EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E) {
1087   CompoundFunc Op = getComplexOp(E->getOpcode());
1088   RValue Val;
1089   return ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
1090 }
1091 
1092 LValue CodeGenFunction::
1093 EmitScalarCompoundAssignWithComplex(const CompoundAssignOperator *E,
1094                                     llvm::Value *&Result) {
1095   CompoundFunc Op = getComplexOp(E->getOpcode());
1096   RValue Val;
1097   LValue Ret = ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
1098   Result = Val.getScalarVal();
1099   return Ret;
1100 }
1101