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