1 //===--- CGExprComplex.cpp - Emit LLVM Code for Complex Exprs -------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This contains code to emit Expr nodes with complex types as LLVM code.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "CodeGenFunction.h"
14 #include "CodeGenModule.h"
15 #include "clang/AST/StmtVisitor.h"
16 #include "llvm/ADT/STLExtras.h"
17 #include "llvm/IR/Constants.h"
18 #include "llvm/IR/Instructions.h"
19 #include "llvm/IR/MDBuilder.h"
20 #include "llvm/IR/Metadata.h"
21 #include <algorithm>
22 using namespace clang;
23 using namespace CodeGen;
24 
25 //===----------------------------------------------------------------------===//
26 //                        Complex Expression Emitter
27 //===----------------------------------------------------------------------===//
28 
29 typedef CodeGenFunction::ComplexPairTy ComplexPairTy;
30 
31 /// Return the complex type that we are meant to emit.
32 static const ComplexType *getComplexType(QualType type) {
33   type = type.getCanonicalType();
34   if (const ComplexType *comp = dyn_cast<ComplexType>(type)) {
35     return comp;
36   } else {
37     return cast<ComplexType>(cast<AtomicType>(type)->getValueType());
38   }
39 }
40 
41 namespace  {
42 class ComplexExprEmitter
43   : public StmtVisitor<ComplexExprEmitter, ComplexPairTy> {
44   CodeGenFunction &CGF;
45   CGBuilderTy &Builder;
46   bool IgnoreReal;
47   bool IgnoreImag;
48 public:
49   ComplexExprEmitter(CodeGenFunction &cgf, bool ir=false, bool ii=false)
50     : CGF(cgf), Builder(CGF.Builder), IgnoreReal(ir), IgnoreImag(ii) {
51   }
52 
53 
54   //===--------------------------------------------------------------------===//
55   //                               Utilities
56   //===--------------------------------------------------------------------===//
57 
58   bool TestAndClearIgnoreReal() {
59     bool I = IgnoreReal;
60     IgnoreReal = false;
61     return I;
62   }
63   bool TestAndClearIgnoreImag() {
64     bool I = IgnoreImag;
65     IgnoreImag = false;
66     return I;
67   }
68 
69   /// EmitLoadOfLValue - Given an expression with complex type that represents a
70   /// value l-value, this method emits the address of the l-value, then loads
71   /// and returns the result.
72   ComplexPairTy EmitLoadOfLValue(const Expr *E) {
73     return EmitLoadOfLValue(CGF.EmitLValue(E), E->getExprLoc());
74   }
75 
76   ComplexPairTy EmitLoadOfLValue(LValue LV, SourceLocation Loc);
77 
78   /// EmitStoreOfComplex - Store the specified real/imag parts into the
79   /// specified value pointer.
80   void EmitStoreOfComplex(ComplexPairTy Val, LValue LV, bool isInit);
81 
82   /// Emit a cast from complex value Val to DestType.
83   ComplexPairTy EmitComplexToComplexCast(ComplexPairTy Val, QualType SrcType,
84                                          QualType DestType, SourceLocation Loc);
85   /// Emit a cast from scalar value Val to DestType.
86   ComplexPairTy EmitScalarToComplexCast(llvm::Value *Val, QualType SrcType,
87                                         QualType DestType, SourceLocation Loc);
88 
89   //===--------------------------------------------------------------------===//
90   //                            Visitor Methods
91   //===--------------------------------------------------------------------===//
92 
93   ComplexPairTy Visit(Expr *E) {
94     ApplyDebugLocation DL(CGF, E);
95     return StmtVisitor<ComplexExprEmitter, ComplexPairTy>::Visit(E);
96   }
97 
98   ComplexPairTy VisitStmt(Stmt *S) {
99     S->dump(CGF.getContext().getSourceManager());
100     llvm_unreachable("Stmt can't have complex result type!");
101   }
102   ComplexPairTy VisitExpr(Expr *S);
103   ComplexPairTy VisitConstantExpr(ConstantExpr *E) {
104     return Visit(E->getSubExpr());
105   }
106   ComplexPairTy VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr());}
107   ComplexPairTy VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
108     return Visit(GE->getResultExpr());
109   }
110   ComplexPairTy VisitImaginaryLiteral(const ImaginaryLiteral *IL);
111   ComplexPairTy
112   VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *PE) {
113     return Visit(PE->getReplacement());
114   }
115   ComplexPairTy VisitCoawaitExpr(CoawaitExpr *S) {
116     return CGF.EmitCoawaitExpr(*S).getComplexVal();
117   }
118   ComplexPairTy VisitCoyieldExpr(CoyieldExpr *S) {
119     return CGF.EmitCoyieldExpr(*S).getComplexVal();
120   }
121   ComplexPairTy VisitUnaryCoawait(const UnaryOperator *E) {
122     return Visit(E->getSubExpr());
123   }
124 
125   ComplexPairTy emitConstant(const CodeGenFunction::ConstantEmission &Constant,
126                              Expr *E) {
127     assert(Constant && "not a constant");
128     if (Constant.isReference())
129       return EmitLoadOfLValue(Constant.getReferenceLValue(CGF, E),
130                               E->getExprLoc());
131 
132     llvm::Constant *pair = Constant.getValue();
133     return ComplexPairTy(pair->getAggregateElement(0U),
134                          pair->getAggregateElement(1U));
135   }
136 
137   // l-values.
138   ComplexPairTy VisitDeclRefExpr(DeclRefExpr *E) {
139     if (CodeGenFunction::ConstantEmission Constant = CGF.tryEmitAsConstant(E))
140       return emitConstant(Constant, E);
141     return EmitLoadOfLValue(E);
142   }
143   ComplexPairTy VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
144     return EmitLoadOfLValue(E);
145   }
146   ComplexPairTy VisitObjCMessageExpr(ObjCMessageExpr *E) {
147     return CGF.EmitObjCMessageExpr(E).getComplexVal();
148   }
149   ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
150   ComplexPairTy VisitMemberExpr(MemberExpr *ME) {
151     if (CodeGenFunction::ConstantEmission Constant =
152             CGF.tryEmitAsConstant(ME)) {
153       CGF.EmitIgnoredExpr(ME->getBase());
154       return emitConstant(Constant, ME);
155     }
156     return EmitLoadOfLValue(ME);
157   }
158   ComplexPairTy VisitOpaqueValueExpr(OpaqueValueExpr *E) {
159     if (E->isGLValue())
160       return EmitLoadOfLValue(CGF.getOrCreateOpaqueLValueMapping(E),
161                               E->getExprLoc());
162     return CGF.getOrCreateOpaqueRValueMapping(E).getComplexVal();
163   }
164 
165   ComplexPairTy VisitPseudoObjectExpr(PseudoObjectExpr *E) {
166     return CGF.EmitPseudoObjectRValue(E).getComplexVal();
167   }
168 
169   // FIXME: CompoundLiteralExpr
170 
171   ComplexPairTy EmitCast(CastKind CK, Expr *Op, QualType DestTy);
172   ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
173     // Unlike for scalars, we don't have to worry about function->ptr demotion
174     // here.
175     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
176   }
177   ComplexPairTy VisitCastExpr(CastExpr *E) {
178     if (const auto *ECE = dyn_cast<ExplicitCastExpr>(E))
179       CGF.CGM.EmitExplicitCastExprType(ECE, &CGF);
180     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
181   }
182   ComplexPairTy VisitCallExpr(const CallExpr *E);
183   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
184 
185   // Operators.
186   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
187                                    bool isInc, bool isPre) {
188     LValue LV = CGF.EmitLValue(E->getSubExpr());
189     return CGF.EmitComplexPrePostIncDec(E, LV, isInc, isPre);
190   }
191   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
192     return VisitPrePostIncDec(E, false, false);
193   }
194   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
195     return VisitPrePostIncDec(E, true, false);
196   }
197   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
198     return VisitPrePostIncDec(E, false, true);
199   }
200   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
201     return VisitPrePostIncDec(E, true, true);
202   }
203   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
204   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
205     TestAndClearIgnoreReal();
206     TestAndClearIgnoreImag();
207     return Visit(E->getSubExpr());
208   }
209   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
210   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
211   // LNot,Real,Imag never return complex.
212   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
213     return Visit(E->getSubExpr());
214   }
215   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
216     return Visit(DAE->getExpr());
217   }
218   ComplexPairTy VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
219     CodeGenFunction::CXXDefaultInitExprScope Scope(CGF);
220     return Visit(DIE->getExpr());
221   }
222   ComplexPairTy VisitExprWithCleanups(ExprWithCleanups *E) {
223     CGF.enterFullExpression(E);
224     CodeGenFunction::RunCleanupsScope Scope(CGF);
225     ComplexPairTy Vals = Visit(E->getSubExpr());
226     // Defend against dominance problems caused by jumps out of expression
227     // evaluation through the shared cleanup block.
228     Scope.ForceCleanup({&Vals.first, &Vals.second});
229     return Vals;
230   }
231   ComplexPairTy VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
232     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
233     QualType Elem = E->getType()->castAs<ComplexType>()->getElementType();
234     llvm::Constant *Null = llvm::Constant::getNullValue(CGF.ConvertType(Elem));
235     return ComplexPairTy(Null, Null);
236   }
237   ComplexPairTy VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
238     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
239     QualType Elem = E->getType()->castAs<ComplexType>()->getElementType();
240     llvm::Constant *Null =
241                        llvm::Constant::getNullValue(CGF.ConvertType(Elem));
242     return ComplexPairTy(Null, Null);
243   }
244 
245   struct BinOpInfo {
246     ComplexPairTy LHS;
247     ComplexPairTy RHS;
248     QualType Ty;  // Computation Type.
249   };
250 
251   BinOpInfo EmitBinOps(const BinaryOperator *E);
252   LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
253                                   ComplexPairTy (ComplexExprEmitter::*Func)
254                                   (const BinOpInfo &),
255                                   RValue &Val);
256   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
257                                    ComplexPairTy (ComplexExprEmitter::*Func)
258                                    (const BinOpInfo &));
259 
260   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
261   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
262   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
263   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
264 
265   ComplexPairTy EmitComplexBinOpLibCall(StringRef LibCallName,
266                                         const BinOpInfo &Op);
267 
268   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
269     return EmitBinAdd(EmitBinOps(E));
270   }
271   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
272     return EmitBinSub(EmitBinOps(E));
273   }
274   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
275     return EmitBinMul(EmitBinOps(E));
276   }
277   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
278     return EmitBinDiv(EmitBinOps(E));
279   }
280 
281   // Compound assignments.
282   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
283     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
284   }
285   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
286     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
287   }
288   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
289     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
290   }
291   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
292     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
293   }
294 
295   // GCC rejects rem/and/or/xor for integer complex.
296   // Logical and/or always return int, never complex.
297 
298   // No comparisons produce a complex result.
299 
300   LValue EmitBinAssignLValue(const BinaryOperator *E,
301                              ComplexPairTy &Val);
302   ComplexPairTy VisitBinAssign     (const BinaryOperator *E);
303   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
304 
305 
306   ComplexPairTy
307   VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
308   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
309 
310   ComplexPairTy VisitInitListExpr(InitListExpr *E);
311 
312   ComplexPairTy VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
313     return EmitLoadOfLValue(E);
314   }
315 
316   ComplexPairTy VisitVAArgExpr(VAArgExpr *E);
317 
318   ComplexPairTy VisitAtomicExpr(AtomicExpr *E) {
319     return CGF.EmitAtomicExpr(E).getComplexVal();
320   }
321 };
322 }  // end anonymous namespace.
323 
324 //===----------------------------------------------------------------------===//
325 //                                Utilities
326 //===----------------------------------------------------------------------===//
327 
328 Address CodeGenFunction::emitAddrOfRealComponent(Address addr,
329                                                  QualType complexType) {
330   return Builder.CreateStructGEP(addr, 0, addr.getName() + ".realp");
331 }
332 
333 Address CodeGenFunction::emitAddrOfImagComponent(Address addr,
334                                                  QualType complexType) {
335   return Builder.CreateStructGEP(addr, 1, addr.getName() + ".imagp");
336 }
337 
338 /// EmitLoadOfLValue - Given an RValue reference for a complex, emit code to
339 /// load the real and imaginary pieces, returning them as Real/Imag.
340 ComplexPairTy ComplexExprEmitter::EmitLoadOfLValue(LValue lvalue,
341                                                    SourceLocation loc) {
342   assert(lvalue.isSimple() && "non-simple complex l-value?");
343   if (lvalue.getType()->isAtomicType())
344     return CGF.EmitAtomicLoad(lvalue, loc).getComplexVal();
345 
346   Address SrcPtr = lvalue.getAddress();
347   bool isVolatile = lvalue.isVolatileQualified();
348 
349   llvm::Value *Real = nullptr, *Imag = nullptr;
350 
351   if (!IgnoreReal || isVolatile) {
352     Address RealP = CGF.emitAddrOfRealComponent(SrcPtr, lvalue.getType());
353     Real = Builder.CreateLoad(RealP, isVolatile, SrcPtr.getName() + ".real");
354   }
355 
356   if (!IgnoreImag || isVolatile) {
357     Address ImagP = CGF.emitAddrOfImagComponent(SrcPtr, lvalue.getType());
358     Imag = Builder.CreateLoad(ImagP, isVolatile, SrcPtr.getName() + ".imag");
359   }
360 
361   return ComplexPairTy(Real, Imag);
362 }
363 
364 /// EmitStoreOfComplex - Store the specified real/imag parts into the
365 /// specified value pointer.
366 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, LValue lvalue,
367                                             bool isInit) {
368   if (lvalue.getType()->isAtomicType() ||
369       (!isInit && CGF.LValueIsSuitableForInlineAtomic(lvalue)))
370     return CGF.EmitAtomicStore(RValue::getComplex(Val), lvalue, isInit);
371 
372   Address Ptr = lvalue.getAddress();
373   Address RealPtr = CGF.emitAddrOfRealComponent(Ptr, lvalue.getType());
374   Address ImagPtr = CGF.emitAddrOfImagComponent(Ptr, lvalue.getType());
375 
376   Builder.CreateStore(Val.first, RealPtr, lvalue.isVolatileQualified());
377   Builder.CreateStore(Val.second, ImagPtr, lvalue.isVolatileQualified());
378 }
379 
380 
381 
382 //===----------------------------------------------------------------------===//
383 //                            Visitor Methods
384 //===----------------------------------------------------------------------===//
385 
386 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
387   CGF.ErrorUnsupported(E, "complex expression");
388   llvm::Type *EltTy =
389     CGF.ConvertType(getComplexType(E->getType())->getElementType());
390   llvm::Value *U = llvm::UndefValue::get(EltTy);
391   return ComplexPairTy(U, U);
392 }
393 
394 ComplexPairTy ComplexExprEmitter::
395 VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
396   llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
397   return ComplexPairTy(llvm::Constant::getNullValue(Imag->getType()), Imag);
398 }
399 
400 
401 ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
402   if (E->getCallReturnType(CGF.getContext())->isReferenceType())
403     return EmitLoadOfLValue(E);
404 
405   return CGF.EmitCallExpr(E).getComplexVal();
406 }
407 
408 ComplexPairTy ComplexExprEmitter::VisitStmtExpr(const StmtExpr *E) {
409   CodeGenFunction::StmtExprEvaluation eval(CGF);
410   Address RetAlloca = CGF.EmitCompoundStmt(*E->getSubStmt(), true);
411   assert(RetAlloca.isValid() && "Expected complex return value");
412   return EmitLoadOfLValue(CGF.MakeAddrLValue(RetAlloca, E->getType()),
413                           E->getExprLoc());
414 }
415 
416 /// Emit a cast from complex value Val to DestType.
417 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
418                                                            QualType SrcType,
419                                                            QualType DestType,
420                                                            SourceLocation Loc) {
421   // Get the src/dest element type.
422   SrcType = SrcType->castAs<ComplexType>()->getElementType();
423   DestType = DestType->castAs<ComplexType>()->getElementType();
424 
425   // C99 6.3.1.6: When a value of complex type is converted to another
426   // complex type, both the real and imaginary parts follow the conversion
427   // rules for the corresponding real types.
428   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType, Loc);
429   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType, Loc);
430   return Val;
431 }
432 
433 ComplexPairTy ComplexExprEmitter::EmitScalarToComplexCast(llvm::Value *Val,
434                                                           QualType SrcType,
435                                                           QualType DestType,
436                                                           SourceLocation Loc) {
437   // Convert the input element to the element type of the complex.
438   DestType = DestType->castAs<ComplexType>()->getElementType();
439   Val = CGF.EmitScalarConversion(Val, SrcType, DestType, Loc);
440 
441   // Return (realval, 0).
442   return ComplexPairTy(Val, llvm::Constant::getNullValue(Val->getType()));
443 }
444 
445 ComplexPairTy ComplexExprEmitter::EmitCast(CastKind CK, Expr *Op,
446                                            QualType DestTy) {
447   switch (CK) {
448   case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!");
449 
450   // Atomic to non-atomic casts may be more than a no-op for some platforms and
451   // for some types.
452   case CK_AtomicToNonAtomic:
453   case CK_NonAtomicToAtomic:
454   case CK_NoOp:
455   case CK_LValueToRValue:
456   case CK_UserDefinedConversion:
457     return Visit(Op);
458 
459   case CK_LValueBitCast: {
460     LValue origLV = CGF.EmitLValue(Op);
461     Address V = origLV.getAddress();
462     V = Builder.CreateElementBitCast(V, CGF.ConvertType(DestTy));
463     return EmitLoadOfLValue(CGF.MakeAddrLValue(V, DestTy), Op->getExprLoc());
464   }
465 
466   case CK_BitCast:
467   case CK_BaseToDerived:
468   case CK_DerivedToBase:
469   case CK_UncheckedDerivedToBase:
470   case CK_Dynamic:
471   case CK_ToUnion:
472   case CK_ArrayToPointerDecay:
473   case CK_FunctionToPointerDecay:
474   case CK_NullToPointer:
475   case CK_NullToMemberPointer:
476   case CK_BaseToDerivedMemberPointer:
477   case CK_DerivedToBaseMemberPointer:
478   case CK_MemberPointerToBoolean:
479   case CK_ReinterpretMemberPointer:
480   case CK_ConstructorConversion:
481   case CK_IntegralToPointer:
482   case CK_PointerToIntegral:
483   case CK_PointerToBoolean:
484   case CK_ToVoid:
485   case CK_VectorSplat:
486   case CK_IntegralCast:
487   case CK_BooleanToSignedIntegral:
488   case CK_IntegralToBoolean:
489   case CK_IntegralToFloating:
490   case CK_FloatingToIntegral:
491   case CK_FloatingToBoolean:
492   case CK_FloatingCast:
493   case CK_CPointerToObjCPointerCast:
494   case CK_BlockPointerToObjCPointerCast:
495   case CK_AnyPointerToBlockPointerCast:
496   case CK_ObjCObjectLValueCast:
497   case CK_FloatingComplexToReal:
498   case CK_FloatingComplexToBoolean:
499   case CK_IntegralComplexToReal:
500   case CK_IntegralComplexToBoolean:
501   case CK_ARCProduceObject:
502   case CK_ARCConsumeObject:
503   case CK_ARCReclaimReturnedObject:
504   case CK_ARCExtendBlockObject:
505   case CK_CopyAndAutoreleaseBlockObject:
506   case CK_BuiltinFnToFnPtr:
507   case CK_ZeroToOCLOpaqueType:
508   case CK_AddressSpaceConversion:
509   case CK_IntToOCLSampler:
510   case CK_FixedPointCast:
511   case CK_FixedPointToBoolean:
512   case CK_FixedPointToIntegral:
513   case CK_IntegralToFixedPoint:
514     llvm_unreachable("invalid cast kind for complex value");
515 
516   case CK_FloatingRealToComplex:
517   case CK_IntegralRealToComplex:
518     return EmitScalarToComplexCast(CGF.EmitScalarExpr(Op), Op->getType(),
519                                    DestTy, Op->getExprLoc());
520 
521   case CK_FloatingComplexCast:
522   case CK_FloatingComplexToIntegralComplex:
523   case CK_IntegralComplexCast:
524   case CK_IntegralComplexToFloatingComplex:
525     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy,
526                                     Op->getExprLoc());
527   }
528 
529   llvm_unreachable("unknown cast resulting in complex value");
530 }
531 
532 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
533   TestAndClearIgnoreReal();
534   TestAndClearIgnoreImag();
535   ComplexPairTy Op = Visit(E->getSubExpr());
536 
537   llvm::Value *ResR, *ResI;
538   if (Op.first->getType()->isFloatingPointTy()) {
539     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
540     ResI = Builder.CreateFNeg(Op.second, "neg.i");
541   } else {
542     ResR = Builder.CreateNeg(Op.first,  "neg.r");
543     ResI = Builder.CreateNeg(Op.second, "neg.i");
544   }
545   return ComplexPairTy(ResR, ResI);
546 }
547 
548 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
549   TestAndClearIgnoreReal();
550   TestAndClearIgnoreImag();
551   // ~(a+ib) = a + i*-b
552   ComplexPairTy Op = Visit(E->getSubExpr());
553   llvm::Value *ResI;
554   if (Op.second->getType()->isFloatingPointTy())
555     ResI = Builder.CreateFNeg(Op.second, "conj.i");
556   else
557     ResI = Builder.CreateNeg(Op.second, "conj.i");
558 
559   return ComplexPairTy(Op.first, ResI);
560 }
561 
562 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
563   llvm::Value *ResR, *ResI;
564 
565   if (Op.LHS.first->getType()->isFloatingPointTy()) {
566     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
567     if (Op.LHS.second && Op.RHS.second)
568       ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
569     else
570       ResI = Op.LHS.second ? Op.LHS.second : Op.RHS.second;
571     assert(ResI && "Only one operand may be real!");
572   } else {
573     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
574     assert(Op.LHS.second && Op.RHS.second &&
575            "Both operands of integer complex operators must be complex!");
576     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
577   }
578   return ComplexPairTy(ResR, ResI);
579 }
580 
581 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
582   llvm::Value *ResR, *ResI;
583   if (Op.LHS.first->getType()->isFloatingPointTy()) {
584     ResR = Builder.CreateFSub(Op.LHS.first, Op.RHS.first, "sub.r");
585     if (Op.LHS.second && Op.RHS.second)
586       ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
587     else
588       ResI = Op.LHS.second ? Op.LHS.second
589                            : Builder.CreateFNeg(Op.RHS.second, "sub.i");
590     assert(ResI && "Only one operand may be real!");
591   } else {
592     ResR = Builder.CreateSub(Op.LHS.first, Op.RHS.first, "sub.r");
593     assert(Op.LHS.second && Op.RHS.second &&
594            "Both operands of integer complex operators must be complex!");
595     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
596   }
597   return ComplexPairTy(ResR, ResI);
598 }
599 
600 /// Emit a libcall for a binary operation on complex types.
601 ComplexPairTy ComplexExprEmitter::EmitComplexBinOpLibCall(StringRef LibCallName,
602                                                           const BinOpInfo &Op) {
603   CallArgList Args;
604   Args.add(RValue::get(Op.LHS.first),
605            Op.Ty->castAs<ComplexType>()->getElementType());
606   Args.add(RValue::get(Op.LHS.second),
607            Op.Ty->castAs<ComplexType>()->getElementType());
608   Args.add(RValue::get(Op.RHS.first),
609            Op.Ty->castAs<ComplexType>()->getElementType());
610   Args.add(RValue::get(Op.RHS.second),
611            Op.Ty->castAs<ComplexType>()->getElementType());
612 
613   // We *must* use the full CG function call building logic here because the
614   // complex type has special ABI handling. We also should not forget about
615   // special calling convention which may be used for compiler builtins.
616 
617   // We create a function qualified type to state that this call does not have
618   // any exceptions.
619   FunctionProtoType::ExtProtoInfo EPI;
620   EPI = EPI.withExceptionSpec(
621       FunctionProtoType::ExceptionSpecInfo(EST_BasicNoexcept));
622   SmallVector<QualType, 4> ArgsQTys(
623       4, Op.Ty->castAs<ComplexType>()->getElementType());
624   QualType FQTy = CGF.getContext().getFunctionType(Op.Ty, ArgsQTys, EPI);
625   const CGFunctionInfo &FuncInfo = CGF.CGM.getTypes().arrangeFreeFunctionCall(
626       Args, cast<FunctionType>(FQTy.getTypePtr()), false);
627 
628   llvm::FunctionType *FTy = CGF.CGM.getTypes().GetFunctionType(FuncInfo);
629   llvm::FunctionCallee Func = CGF.CGM.CreateRuntimeFunction(
630       FTy, LibCallName, llvm::AttributeList(), true);
631   CGCallee Callee = CGCallee::forDirect(Func, FQTy->getAs<FunctionProtoType>());
632 
633   llvm::CallBase *Call;
634   RValue Res = CGF.EmitCall(FuncInfo, Callee, ReturnValueSlot(), Args, &Call);
635   Call->setCallingConv(CGF.CGM.getRuntimeCC());
636   return Res.getComplexVal();
637 }
638 
639 /// Lookup the libcall name for a given floating point type complex
640 /// multiply.
641 static StringRef getComplexMultiplyLibCallName(llvm::Type *Ty) {
642   switch (Ty->getTypeID()) {
643   default:
644     llvm_unreachable("Unsupported floating point type!");
645   case llvm::Type::HalfTyID:
646     return "__mulhc3";
647   case llvm::Type::FloatTyID:
648     return "__mulsc3";
649   case llvm::Type::DoubleTyID:
650     return "__muldc3";
651   case llvm::Type::PPC_FP128TyID:
652     return "__multc3";
653   case llvm::Type::X86_FP80TyID:
654     return "__mulxc3";
655   case llvm::Type::FP128TyID:
656     return "__multc3";
657   }
658 }
659 
660 // See C11 Annex G.5.1 for the semantics of multiplicative operators on complex
661 // typed values.
662 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
663   using llvm::Value;
664   Value *ResR, *ResI;
665   llvm::MDBuilder MDHelper(CGF.getLLVMContext());
666 
667   if (Op.LHS.first->getType()->isFloatingPointTy()) {
668     // The general formulation is:
669     // (a + ib) * (c + id) = (a * c - b * d) + i(a * d + b * c)
670     //
671     // But we can fold away components which would be zero due to a real
672     // operand according to C11 Annex G.5.1p2.
673     // FIXME: C11 also provides for imaginary types which would allow folding
674     // still more of this within the type system.
675 
676     if (Op.LHS.second && Op.RHS.second) {
677       // If both operands are complex, emit the core math directly, and then
678       // test for NaNs. If we find NaNs in the result, we delegate to a libcall
679       // to carefully re-compute the correct infinity representation if
680       // possible. The expectation is that the presence of NaNs here is
681       // *extremely* rare, and so the cost of the libcall is almost irrelevant.
682       // This is good, because the libcall re-computes the core multiplication
683       // exactly the same as we do here and re-tests for NaNs in order to be
684       // a generic complex*complex libcall.
685 
686       // First compute the four products.
687       Value *AC = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul_ac");
688       Value *BD = Builder.CreateFMul(Op.LHS.second, Op.RHS.second, "mul_bd");
689       Value *AD = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul_ad");
690       Value *BC = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul_bc");
691 
692       // The real part is the difference of the first two, the imaginary part is
693       // the sum of the second.
694       ResR = Builder.CreateFSub(AC, BD, "mul_r");
695       ResI = Builder.CreateFAdd(AD, BC, "mul_i");
696 
697       // Emit the test for the real part becoming NaN and create a branch to
698       // handle it. We test for NaN by comparing the number to itself.
699       Value *IsRNaN = Builder.CreateFCmpUNO(ResR, ResR, "isnan_cmp");
700       llvm::BasicBlock *ContBB = CGF.createBasicBlock("complex_mul_cont");
701       llvm::BasicBlock *INaNBB = CGF.createBasicBlock("complex_mul_imag_nan");
702       llvm::Instruction *Branch = Builder.CreateCondBr(IsRNaN, INaNBB, ContBB);
703       llvm::BasicBlock *OrigBB = Branch->getParent();
704 
705       // Give hint that we very much don't expect to see NaNs.
706       // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
707       llvm::MDNode *BrWeight = MDHelper.createBranchWeights(1, (1U << 20) - 1);
708       Branch->setMetadata(llvm::LLVMContext::MD_prof, BrWeight);
709 
710       // Now test the imaginary part and create its branch.
711       CGF.EmitBlock(INaNBB);
712       Value *IsINaN = Builder.CreateFCmpUNO(ResI, ResI, "isnan_cmp");
713       llvm::BasicBlock *LibCallBB = CGF.createBasicBlock("complex_mul_libcall");
714       Branch = Builder.CreateCondBr(IsINaN, LibCallBB, ContBB);
715       Branch->setMetadata(llvm::LLVMContext::MD_prof, BrWeight);
716 
717       // Now emit the libcall on this slowest of the slow paths.
718       CGF.EmitBlock(LibCallBB);
719       Value *LibCallR, *LibCallI;
720       std::tie(LibCallR, LibCallI) = EmitComplexBinOpLibCall(
721           getComplexMultiplyLibCallName(Op.LHS.first->getType()), Op);
722       Builder.CreateBr(ContBB);
723 
724       // Finally continue execution by phi-ing together the different
725       // computation paths.
726       CGF.EmitBlock(ContBB);
727       llvm::PHINode *RealPHI = Builder.CreatePHI(ResR->getType(), 3, "real_mul_phi");
728       RealPHI->addIncoming(ResR, OrigBB);
729       RealPHI->addIncoming(ResR, INaNBB);
730       RealPHI->addIncoming(LibCallR, LibCallBB);
731       llvm::PHINode *ImagPHI = Builder.CreatePHI(ResI->getType(), 3, "imag_mul_phi");
732       ImagPHI->addIncoming(ResI, OrigBB);
733       ImagPHI->addIncoming(ResI, INaNBB);
734       ImagPHI->addIncoming(LibCallI, LibCallBB);
735       return ComplexPairTy(RealPHI, ImagPHI);
736     }
737     assert((Op.LHS.second || Op.RHS.second) &&
738            "At least one operand must be complex!");
739 
740     // If either of the operands is a real rather than a complex, the
741     // imaginary component is ignored when computing the real component of the
742     // result.
743     ResR = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
744 
745     ResI = Op.LHS.second
746                ? Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il")
747                : Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
748   } else {
749     assert(Op.LHS.second && Op.RHS.second &&
750            "Both operands of integer complex operators must be complex!");
751     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
752     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second, "mul.rr");
753     ResR = Builder.CreateSub(ResRl, ResRr, "mul.r");
754 
755     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
756     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
757     ResI = Builder.CreateAdd(ResIl, ResIr, "mul.i");
758   }
759   return ComplexPairTy(ResR, ResI);
760 }
761 
762 // See C11 Annex G.5.1 for the semantics of multiplicative operators on complex
763 // typed values.
764 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
765   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
766   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
767 
768   llvm::Value *DSTr, *DSTi;
769   if (LHSr->getType()->isFloatingPointTy()) {
770     // If we have a complex operand on the RHS and FastMath is not allowed, we
771     // delegate to a libcall to handle all of the complexities and minimize
772     // underflow/overflow cases. When FastMath is allowed we construct the
773     // divide inline using the same algorithm as for integer operands.
774     //
775     // FIXME: We would be able to avoid the libcall in many places if we
776     // supported imaginary types in addition to complex types.
777     if (RHSi && !CGF.getLangOpts().FastMath) {
778       BinOpInfo LibCallOp = Op;
779       // If LHS was a real, supply a null imaginary part.
780       if (!LHSi)
781         LibCallOp.LHS.second = llvm::Constant::getNullValue(LHSr->getType());
782 
783       switch (LHSr->getType()->getTypeID()) {
784       default:
785         llvm_unreachable("Unsupported floating point type!");
786       case llvm::Type::HalfTyID:
787         return EmitComplexBinOpLibCall("__divhc3", LibCallOp);
788       case llvm::Type::FloatTyID:
789         return EmitComplexBinOpLibCall("__divsc3", LibCallOp);
790       case llvm::Type::DoubleTyID:
791         return EmitComplexBinOpLibCall("__divdc3", LibCallOp);
792       case llvm::Type::PPC_FP128TyID:
793         return EmitComplexBinOpLibCall("__divtc3", LibCallOp);
794       case llvm::Type::X86_FP80TyID:
795         return EmitComplexBinOpLibCall("__divxc3", LibCallOp);
796       case llvm::Type::FP128TyID:
797         return EmitComplexBinOpLibCall("__divtc3", LibCallOp);
798       }
799     } else if (RHSi) {
800       if (!LHSi)
801         LHSi = llvm::Constant::getNullValue(RHSi->getType());
802 
803       // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
804       llvm::Value *AC = Builder.CreateFMul(LHSr, RHSr); // a*c
805       llvm::Value *BD = Builder.CreateFMul(LHSi, RHSi); // b*d
806       llvm::Value *ACpBD = Builder.CreateFAdd(AC, BD); // ac+bd
807 
808       llvm::Value *CC = Builder.CreateFMul(RHSr, RHSr); // c*c
809       llvm::Value *DD = Builder.CreateFMul(RHSi, RHSi); // d*d
810       llvm::Value *CCpDD = Builder.CreateFAdd(CC, DD); // cc+dd
811 
812       llvm::Value *BC = Builder.CreateFMul(LHSi, RHSr); // b*c
813       llvm::Value *AD = Builder.CreateFMul(LHSr, RHSi); // a*d
814       llvm::Value *BCmAD = Builder.CreateFSub(BC, AD); // bc-ad
815 
816       DSTr = Builder.CreateFDiv(ACpBD, CCpDD);
817       DSTi = Builder.CreateFDiv(BCmAD, CCpDD);
818     } else {
819       assert(LHSi && "Can have at most one non-complex operand!");
820 
821       DSTr = Builder.CreateFDiv(LHSr, RHSr);
822       DSTi = Builder.CreateFDiv(LHSi, RHSr);
823     }
824   } else {
825     assert(Op.LHS.second && Op.RHS.second &&
826            "Both operands of integer complex operators must be complex!");
827     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
828     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr); // a*c
829     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi); // b*d
830     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2); // ac+bd
831 
832     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr); // c*c
833     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi); // d*d
834     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5); // cc+dd
835 
836     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr); // b*c
837     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi); // a*d
838     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8); // bc-ad
839 
840     if (Op.Ty->castAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
841       DSTr = Builder.CreateUDiv(Tmp3, Tmp6);
842       DSTi = Builder.CreateUDiv(Tmp9, Tmp6);
843     } else {
844       DSTr = Builder.CreateSDiv(Tmp3, Tmp6);
845       DSTi = Builder.CreateSDiv(Tmp9, Tmp6);
846     }
847   }
848 
849   return ComplexPairTy(DSTr, DSTi);
850 }
851 
852 ComplexExprEmitter::BinOpInfo
853 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
854   TestAndClearIgnoreReal();
855   TestAndClearIgnoreImag();
856   BinOpInfo Ops;
857   if (E->getLHS()->getType()->isRealFloatingType())
858     Ops.LHS = ComplexPairTy(CGF.EmitScalarExpr(E->getLHS()), nullptr);
859   else
860     Ops.LHS = Visit(E->getLHS());
861   if (E->getRHS()->getType()->isRealFloatingType())
862     Ops.RHS = ComplexPairTy(CGF.EmitScalarExpr(E->getRHS()), nullptr);
863   else
864     Ops.RHS = Visit(E->getRHS());
865 
866   Ops.Ty = E->getType();
867   return Ops;
868 }
869 
870 
871 LValue ComplexExprEmitter::
872 EmitCompoundAssignLValue(const CompoundAssignOperator *E,
873           ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&),
874                          RValue &Val) {
875   TestAndClearIgnoreReal();
876   TestAndClearIgnoreImag();
877   QualType LHSTy = E->getLHS()->getType();
878   if (const AtomicType *AT = LHSTy->getAs<AtomicType>())
879     LHSTy = AT->getValueType();
880 
881   BinOpInfo OpInfo;
882 
883   // Load the RHS and LHS operands.
884   // __block variables need to have the rhs evaluated first, plus this should
885   // improve codegen a little.
886   OpInfo.Ty = E->getComputationResultType();
887   QualType ComplexElementTy = cast<ComplexType>(OpInfo.Ty)->getElementType();
888 
889   // The RHS should have been converted to the computation type.
890   if (E->getRHS()->getType()->isRealFloatingType()) {
891     assert(
892         CGF.getContext()
893             .hasSameUnqualifiedType(ComplexElementTy, E->getRHS()->getType()));
894     OpInfo.RHS = ComplexPairTy(CGF.EmitScalarExpr(E->getRHS()), nullptr);
895   } else {
896     assert(CGF.getContext()
897                .hasSameUnqualifiedType(OpInfo.Ty, E->getRHS()->getType()));
898     OpInfo.RHS = Visit(E->getRHS());
899   }
900 
901   LValue LHS = CGF.EmitLValue(E->getLHS());
902 
903   // Load from the l-value and convert it.
904   SourceLocation Loc = E->getExprLoc();
905   if (LHSTy->isAnyComplexType()) {
906     ComplexPairTy LHSVal = EmitLoadOfLValue(LHS, Loc);
907     OpInfo.LHS = EmitComplexToComplexCast(LHSVal, LHSTy, OpInfo.Ty, Loc);
908   } else {
909     llvm::Value *LHSVal = CGF.EmitLoadOfScalar(LHS, Loc);
910     // For floating point real operands we can directly pass the scalar form
911     // to the binary operator emission and potentially get more efficient code.
912     if (LHSTy->isRealFloatingType()) {
913       if (!CGF.getContext().hasSameUnqualifiedType(ComplexElementTy, LHSTy))
914         LHSVal = CGF.EmitScalarConversion(LHSVal, LHSTy, ComplexElementTy, Loc);
915       OpInfo.LHS = ComplexPairTy(LHSVal, nullptr);
916     } else {
917       OpInfo.LHS = EmitScalarToComplexCast(LHSVal, LHSTy, OpInfo.Ty, Loc);
918     }
919   }
920 
921   // Expand the binary operator.
922   ComplexPairTy Result = (this->*Func)(OpInfo);
923 
924   // Truncate the result and store it into the LHS lvalue.
925   if (LHSTy->isAnyComplexType()) {
926     ComplexPairTy ResVal =
927         EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy, Loc);
928     EmitStoreOfComplex(ResVal, LHS, /*isInit*/ false);
929     Val = RValue::getComplex(ResVal);
930   } else {
931     llvm::Value *ResVal =
932         CGF.EmitComplexToScalarConversion(Result, OpInfo.Ty, LHSTy, Loc);
933     CGF.EmitStoreOfScalar(ResVal, LHS, /*isInit*/ false);
934     Val = RValue::get(ResVal);
935   }
936 
937   return LHS;
938 }
939 
940 // Compound assignments.
941 ComplexPairTy ComplexExprEmitter::
942 EmitCompoundAssign(const CompoundAssignOperator *E,
943                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
944   RValue Val;
945   LValue LV = EmitCompoundAssignLValue(E, Func, Val);
946 
947   // The result of an assignment in C is the assigned r-value.
948   if (!CGF.getLangOpts().CPlusPlus)
949     return Val.getComplexVal();
950 
951   // If the lvalue is non-volatile, return the computed value of the assignment.
952   if (!LV.isVolatileQualified())
953     return Val.getComplexVal();
954 
955   return EmitLoadOfLValue(LV, E->getExprLoc());
956 }
957 
958 LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
959                                                ComplexPairTy &Val) {
960   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
961                                                  E->getRHS()->getType()) &&
962          "Invalid assignment");
963   TestAndClearIgnoreReal();
964   TestAndClearIgnoreImag();
965 
966   // Emit the RHS.  __block variables need the RHS evaluated first.
967   Val = Visit(E->getRHS());
968 
969   // Compute the address to store into.
970   LValue LHS = CGF.EmitLValue(E->getLHS());
971 
972   // Store the result value into the LHS lvalue.
973   EmitStoreOfComplex(Val, LHS, /*isInit*/ false);
974 
975   return LHS;
976 }
977 
978 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
979   ComplexPairTy Val;
980   LValue LV = EmitBinAssignLValue(E, Val);
981 
982   // The result of an assignment in C is the assigned r-value.
983   if (!CGF.getLangOpts().CPlusPlus)
984     return Val;
985 
986   // If the lvalue is non-volatile, return the computed value of the assignment.
987   if (!LV.isVolatileQualified())
988     return Val;
989 
990   return EmitLoadOfLValue(LV, E->getExprLoc());
991 }
992 
993 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
994   CGF.EmitIgnoredExpr(E->getLHS());
995   return Visit(E->getRHS());
996 }
997 
998 ComplexPairTy ComplexExprEmitter::
999 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
1000   TestAndClearIgnoreReal();
1001   TestAndClearIgnoreImag();
1002   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
1003   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
1004   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
1005 
1006   // Bind the common expression if necessary.
1007   CodeGenFunction::OpaqueValueMapping binding(CGF, E);
1008 
1009 
1010   CodeGenFunction::ConditionalEvaluation eval(CGF);
1011   CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock,
1012                            CGF.getProfileCount(E));
1013 
1014   eval.begin(CGF);
1015   CGF.EmitBlock(LHSBlock);
1016   CGF.incrementProfileCounter(E);
1017   ComplexPairTy LHS = Visit(E->getTrueExpr());
1018   LHSBlock = Builder.GetInsertBlock();
1019   CGF.EmitBranch(ContBlock);
1020   eval.end(CGF);
1021 
1022   eval.begin(CGF);
1023   CGF.EmitBlock(RHSBlock);
1024   ComplexPairTy RHS = Visit(E->getFalseExpr());
1025   RHSBlock = Builder.GetInsertBlock();
1026   CGF.EmitBlock(ContBlock);
1027   eval.end(CGF);
1028 
1029   // Create a PHI node for the real part.
1030   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.r");
1031   RealPN->addIncoming(LHS.first, LHSBlock);
1032   RealPN->addIncoming(RHS.first, RHSBlock);
1033 
1034   // Create a PHI node for the imaginary part.
1035   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.i");
1036   ImagPN->addIncoming(LHS.second, LHSBlock);
1037   ImagPN->addIncoming(RHS.second, RHSBlock);
1038 
1039   return ComplexPairTy(RealPN, ImagPN);
1040 }
1041 
1042 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
1043   return Visit(E->getChosenSubExpr());
1044 }
1045 
1046 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
1047     bool Ignore = TestAndClearIgnoreReal();
1048     (void)Ignore;
1049     assert (Ignore == false && "init list ignored");
1050     Ignore = TestAndClearIgnoreImag();
1051     (void)Ignore;
1052     assert (Ignore == false && "init list ignored");
1053 
1054   if (E->getNumInits() == 2) {
1055     llvm::Value *Real = CGF.EmitScalarExpr(E->getInit(0));
1056     llvm::Value *Imag = CGF.EmitScalarExpr(E->getInit(1));
1057     return ComplexPairTy(Real, Imag);
1058   } else if (E->getNumInits() == 1) {
1059     return Visit(E->getInit(0));
1060   }
1061 
1062   // Empty init list initializes to null
1063   assert(E->getNumInits() == 0 && "Unexpected number of inits");
1064   QualType Ty = E->getType()->castAs<ComplexType>()->getElementType();
1065   llvm::Type* LTy = CGF.ConvertType(Ty);
1066   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
1067   return ComplexPairTy(zeroConstant, zeroConstant);
1068 }
1069 
1070 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
1071   Address ArgValue = Address::invalid();
1072   Address ArgPtr = CGF.EmitVAArg(E, ArgValue);
1073 
1074   if (!ArgPtr.isValid()) {
1075     CGF.ErrorUnsupported(E, "complex va_arg expression");
1076     llvm::Type *EltTy =
1077       CGF.ConvertType(E->getType()->castAs<ComplexType>()->getElementType());
1078     llvm::Value *U = llvm::UndefValue::get(EltTy);
1079     return ComplexPairTy(U, U);
1080   }
1081 
1082   return EmitLoadOfLValue(CGF.MakeAddrLValue(ArgPtr, E->getType()),
1083                           E->getExprLoc());
1084 }
1085 
1086 //===----------------------------------------------------------------------===//
1087 //                         Entry Point into this File
1088 //===----------------------------------------------------------------------===//
1089 
1090 /// EmitComplexExpr - Emit the computation of the specified expression of
1091 /// complex type, ignoring the result.
1092 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
1093                                                bool IgnoreImag) {
1094   assert(E && getComplexType(E->getType()) &&
1095          "Invalid complex expression to emit");
1096 
1097   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag)
1098       .Visit(const_cast<Expr *>(E));
1099 }
1100 
1101 void CodeGenFunction::EmitComplexExprIntoLValue(const Expr *E, LValue dest,
1102                                                 bool isInit) {
1103   assert(E && getComplexType(E->getType()) &&
1104          "Invalid complex expression to emit");
1105   ComplexExprEmitter Emitter(*this);
1106   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
1107   Emitter.EmitStoreOfComplex(Val, dest, isInit);
1108 }
1109 
1110 /// EmitStoreOfComplex - Store a complex number into the specified l-value.
1111 void CodeGenFunction::EmitStoreOfComplex(ComplexPairTy V, LValue dest,
1112                                          bool isInit) {
1113   ComplexExprEmitter(*this).EmitStoreOfComplex(V, dest, isInit);
1114 }
1115 
1116 /// EmitLoadOfComplex - Load a complex number from the specified address.
1117 ComplexPairTy CodeGenFunction::EmitLoadOfComplex(LValue src,
1118                                                  SourceLocation loc) {
1119   return ComplexExprEmitter(*this).EmitLoadOfLValue(src, loc);
1120 }
1121 
1122 LValue CodeGenFunction::EmitComplexAssignmentLValue(const BinaryOperator *E) {
1123   assert(E->getOpcode() == BO_Assign);
1124   ComplexPairTy Val; // ignored
1125   return ComplexExprEmitter(*this).EmitBinAssignLValue(E, Val);
1126 }
1127 
1128 typedef ComplexPairTy (ComplexExprEmitter::*CompoundFunc)(
1129     const ComplexExprEmitter::BinOpInfo &);
1130 
1131 static CompoundFunc getComplexOp(BinaryOperatorKind Op) {
1132   switch (Op) {
1133   case BO_MulAssign: return &ComplexExprEmitter::EmitBinMul;
1134   case BO_DivAssign: return &ComplexExprEmitter::EmitBinDiv;
1135   case BO_SubAssign: return &ComplexExprEmitter::EmitBinSub;
1136   case BO_AddAssign: return &ComplexExprEmitter::EmitBinAdd;
1137   default:
1138     llvm_unreachable("unexpected complex compound assignment");
1139   }
1140 }
1141 
1142 LValue CodeGenFunction::
1143 EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E) {
1144   CompoundFunc Op = getComplexOp(E->getOpcode());
1145   RValue Val;
1146   return ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
1147 }
1148 
1149 LValue CodeGenFunction::
1150 EmitScalarCompoundAssignWithComplex(const CompoundAssignOperator *E,
1151                                     llvm::Value *&Result) {
1152   CompoundFunc Op = getComplexOp(E->getOpcode());
1153   RValue Val;
1154   LValue Ret = ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
1155   Result = Val.getScalarVal();
1156   return Ret;
1157 }
1158