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/Constants.h"
19 #include "llvm/Function.h"
20 #include "llvm/ADT/SmallString.h"
21 #include "llvm/Support/Compiler.h"
22 using namespace clang;
23 using namespace CodeGen;
24 
25 //===----------------------------------------------------------------------===//
26 //                        Complex Expression Emitter
27 //===----------------------------------------------------------------------===//
28 
29 typedef CodeGenFunction::ComplexPairTy ComplexPairTy;
30 
31 namespace  {
32 class VISIBILITY_HIDDEN ComplexExprEmitter
33   : public StmtVisitor<ComplexExprEmitter, ComplexPairTy> {
34   CodeGenFunction &CGF;
35   CGBuilderTy &Builder;
36   // True is we should ignore the value of a
37   bool IgnoreReal;
38   bool IgnoreImag;
39   // True if we should ignore the value of a=b
40   bool IgnoreRealAssign;
41   bool IgnoreImagAssign;
42 public:
43   ComplexExprEmitter(CodeGenFunction &cgf, bool ir=false, bool ii=false,
44                      bool irn=false, bool iin=false)
45     : CGF(cgf), Builder(CGF.Builder), IgnoreReal(ir), IgnoreImag(ii),
46     IgnoreRealAssign(irn), IgnoreImagAssign(iin) {
47   }
48 
49 
50   //===--------------------------------------------------------------------===//
51   //                               Utilities
52   //===--------------------------------------------------------------------===//
53 
54   bool TestAndClearIgnoreReal() {
55     bool I = IgnoreReal;
56     IgnoreReal = false;
57     return I;
58   }
59   bool TestAndClearIgnoreImag() {
60     bool I = IgnoreImag;
61     IgnoreImag = false;
62     return I;
63   }
64   bool TestAndClearIgnoreRealAssign() {
65     bool I = IgnoreRealAssign;
66     IgnoreRealAssign = false;
67     return I;
68   }
69   bool TestAndClearIgnoreImagAssign() {
70     bool I = IgnoreImagAssign;
71     IgnoreImagAssign = false;
72     return I;
73   }
74 
75   /// EmitLoadOfLValue - Given an expression with complex type that represents a
76   /// value l-value, this method emits the address of the l-value, then loads
77   /// and returns the result.
78   ComplexPairTy EmitLoadOfLValue(const Expr *E) {
79     LValue LV = CGF.EmitLValue(E);
80     return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
81   }
82 
83   /// EmitLoadOfComplex - Given a pointer to a complex value, emit code to load
84   /// the real and imaginary pieces.
85   ComplexPairTy EmitLoadOfComplex(llvm::Value *SrcPtr, bool isVolatile);
86 
87   /// EmitStoreOfComplex - Store the specified real/imag parts into the
88   /// specified value pointer.
89   void EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *ResPtr, bool isVol);
90 
91   /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
92   ComplexPairTy EmitComplexToComplexCast(ComplexPairTy Val, QualType SrcType,
93                                          QualType DestType);
94 
95   //===--------------------------------------------------------------------===//
96   //                            Visitor Methods
97   //===--------------------------------------------------------------------===//
98 
99   ComplexPairTy VisitStmt(Stmt *S) {
100     S->dump(CGF.getContext().getSourceManager());
101     assert(0 && "Stmt can't have complex result type!");
102     return ComplexPairTy();
103   }
104   ComplexPairTy VisitExpr(Expr *S);
105   ComplexPairTy VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr());}
106   ComplexPairTy VisitImaginaryLiteral(const ImaginaryLiteral *IL);
107 
108   // l-values.
109   ComplexPairTy VisitDeclRefExpr(const Expr *E) { return EmitLoadOfLValue(E); }
110   ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
111   ComplexPairTy VisitMemberExpr(const Expr *E) { return EmitLoadOfLValue(E); }
112 
113   // FIXME: CompoundLiteralExpr
114 
115   ComplexPairTy EmitCast(Expr *Op, QualType DestTy);
116   ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
117     // Unlike for scalars, we don't have to worry about function->ptr demotion
118     // here.
119     return EmitCast(E->getSubExpr(), E->getType());
120   }
121   ComplexPairTy VisitCastExpr(CastExpr *E) {
122     return EmitCast(E->getSubExpr(), E->getType());
123   }
124   ComplexPairTy VisitCallExpr(const CallExpr *E);
125   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
126 
127   // Operators.
128   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
129                                    bool isInc, bool isPre);
130   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
131     return VisitPrePostIncDec(E, false, false);
132   }
133   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
134     return VisitPrePostIncDec(E, true, false);
135   }
136   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
137     return VisitPrePostIncDec(E, false, true);
138   }
139   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
140     return VisitPrePostIncDec(E, true, true);
141   }
142   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
143   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
144     TestAndClearIgnoreReal();
145     TestAndClearIgnoreImag();
146     TestAndClearIgnoreRealAssign();
147     TestAndClearIgnoreImagAssign();
148     return Visit(E->getSubExpr());
149   }
150   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
151   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
152   // LNot,Real,Imag never return complex.
153   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
154     return Visit(E->getSubExpr());
155   }
156   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
157     return Visit(DAE->getExpr());
158   }
159   ComplexPairTy VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) {
160     return CGF.EmitCXXExprWithTemporaries(E).getComplexVal();
161   }
162   ComplexPairTy VisitCXXZeroInitValueExpr(CXXZeroInitValueExpr *E) {
163     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
164     QualType Elem = E->getType()->getAsComplexType()->getElementType();
165     llvm::Constant *Null = llvm::Constant::getNullValue(CGF.ConvertType(Elem));
166     return ComplexPairTy(Null, Null);
167   }
168   ComplexPairTy VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
169     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
170     QualType Elem = E->getType()->getAsComplexType()->getElementType();
171     llvm::Constant *Null = llvm::Constant::getNullValue(CGF.ConvertType(Elem));
172     return ComplexPairTy(Null, Null);
173   }
174 
175   struct BinOpInfo {
176     ComplexPairTy LHS;
177     ComplexPairTy RHS;
178     QualType Ty;  // Computation Type.
179   };
180 
181   BinOpInfo EmitBinOps(const BinaryOperator *E);
182   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
183                                    ComplexPairTy (ComplexExprEmitter::*Func)
184                                    (const BinOpInfo &));
185 
186   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
187   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
188   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
189   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
190 
191   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
192     return EmitBinMul(EmitBinOps(E));
193   }
194   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
195     return EmitBinAdd(EmitBinOps(E));
196   }
197   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
198     return EmitBinSub(EmitBinOps(E));
199   }
200   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
201     return EmitBinDiv(EmitBinOps(E));
202   }
203 
204   // Compound assignments.
205   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
206     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
207   }
208   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
209     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
210   }
211   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
212     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
213   }
214   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
215     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
216   }
217 
218   // GCC rejects rem/and/or/xor for integer complex.
219   // Logical and/or always return int, never complex.
220 
221   // No comparisons produce a complex result.
222   ComplexPairTy VisitBinAssign     (const BinaryOperator *E);
223   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
224 
225 
226   ComplexPairTy VisitConditionalOperator(const ConditionalOperator *CO);
227   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
228 
229   ComplexPairTy VisitInitListExpr(InitListExpr *E);
230 
231   ComplexPairTy VisitVAArgExpr(VAArgExpr *E);
232 };
233 }  // end anonymous namespace.
234 
235 //===----------------------------------------------------------------------===//
236 //                                Utilities
237 //===----------------------------------------------------------------------===//
238 
239 /// EmitLoadOfComplex - Given an RValue reference for a complex, emit code to
240 /// load the real and imaginary pieces, returning them as Real/Imag.
241 ComplexPairTy ComplexExprEmitter::EmitLoadOfComplex(llvm::Value *SrcPtr,
242                                                     bool isVolatile) {
243   llvm::SmallString<64> Name(SrcPtr->getNameStart(),
244                              SrcPtr->getNameStart()+SrcPtr->getNameLen());
245 
246   llvm::Value *Real=0, *Imag=0;
247 
248   if (!IgnoreReal) {
249     Name += ".realp";
250     llvm::Value *RealPtr = Builder.CreateStructGEP(SrcPtr, 0, Name.c_str());
251 
252     Name.pop_back();  // .realp -> .real
253     Real = Builder.CreateLoad(RealPtr, isVolatile, Name.c_str());
254     Name.resize(Name.size()-4); // .real -> .imagp
255   }
256 
257   if (!IgnoreImag) {
258     Name += "imagp";
259 
260     llvm::Value *ImagPtr = Builder.CreateStructGEP(SrcPtr, 1, Name.c_str());
261 
262     Name.pop_back();  // .imagp -> .imag
263     Imag = Builder.CreateLoad(ImagPtr, isVolatile, Name.c_str());
264   }
265   return ComplexPairTy(Real, Imag);
266 }
267 
268 /// EmitStoreOfComplex - Store the specified real/imag parts into the
269 /// specified value pointer.
270 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *Ptr,
271                                             bool isVolatile) {
272   llvm::Value *RealPtr = Builder.CreateStructGEP(Ptr, 0, "real");
273   llvm::Value *ImagPtr = Builder.CreateStructGEP(Ptr, 1, "imag");
274 
275   Builder.CreateStore(Val.first, RealPtr, isVolatile);
276   Builder.CreateStore(Val.second, ImagPtr, isVolatile);
277 }
278 
279 
280 
281 //===----------------------------------------------------------------------===//
282 //                            Visitor Methods
283 //===----------------------------------------------------------------------===//
284 
285 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
286   CGF.ErrorUnsupported(E, "complex expression");
287   const llvm::Type *EltTy =
288     CGF.ConvertType(E->getType()->getAsComplexType()->getElementType());
289   llvm::Value *U = llvm::UndefValue::get(EltTy);
290   return ComplexPairTy(U, U);
291 }
292 
293 ComplexPairTy ComplexExprEmitter::
294 VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
295   llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
296   return ComplexPairTy(llvm::Constant::getNullValue(Imag->getType()), Imag);
297 }
298 
299 
300 ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
301   if (E->getCallReturnType()->isReferenceType())
302     return EmitLoadOfLValue(E);
303 
304   return CGF.EmitCallExpr(E).getComplexVal();
305 }
306 
307 ComplexPairTy ComplexExprEmitter::VisitStmtExpr(const StmtExpr *E) {
308   return CGF.EmitCompoundStmt(*E->getSubStmt(), true).getComplexVal();
309 }
310 
311 /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
312 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
313                                                            QualType SrcType,
314                                                            QualType DestType) {
315   // Get the src/dest element type.
316   SrcType = SrcType->getAsComplexType()->getElementType();
317   DestType = DestType->getAsComplexType()->getElementType();
318 
319   // C99 6.3.1.6: When a value of complex type is converted to another
320   // complex type, both the real and imaginary parts follow the conversion
321   // rules for the corresponding real types.
322   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType);
323   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType);
324   return Val;
325 }
326 
327 ComplexPairTy ComplexExprEmitter::EmitCast(Expr *Op, QualType DestTy) {
328   // Two cases here: cast from (complex to complex) and (scalar to complex).
329   if (Op->getType()->isAnyComplexType())
330     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
331 
332   // C99 6.3.1.7: When a value of real type is converted to a complex type, the
333   // real part of the complex result value is determined by the rules of
334   // conversion to the corresponding real type and the imaginary part of the
335   // complex result value is a positive zero or an unsigned zero.
336   llvm::Value *Elt = CGF.EmitScalarExpr(Op);
337 
338   // Convert the input element to the element type of the complex.
339   DestTy = DestTy->getAsComplexType()->getElementType();
340   Elt = CGF.EmitScalarConversion(Elt, Op->getType(), DestTy);
341 
342   // Return (realval, 0).
343   return ComplexPairTy(Elt, llvm::Constant::getNullValue(Elt->getType()));
344 }
345 
346 ComplexPairTy ComplexExprEmitter::VisitPrePostIncDec(const UnaryOperator *E,
347                                                      bool isInc, bool isPre) {
348   LValue LV = CGF.EmitLValue(E->getSubExpr());
349   ComplexPairTy InVal = EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
350 
351   llvm::Value *NextVal;
352   if (isa<llvm::IntegerType>(InVal.first->getType())) {
353     uint64_t AmountVal = isInc ? 1 : -1;
354     NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
355   } else {
356     QualType ElemTy = E->getType()->getAsComplexType()->getElementType();
357     llvm::APFloat FVal(CGF.getContext().getFloatTypeSemantics(ElemTy), 1);
358     if (!isInc)
359       FVal.changeSign();
360     NextVal = llvm::ConstantFP::get(FVal);
361   }
362 
363   // Add the inc/dec to the real part.
364   NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
365 
366   ComplexPairTy IncVal(NextVal, InVal.second);
367 
368   // Store the updated result through the lvalue.
369   EmitStoreOfComplex(IncVal, LV.getAddress(), LV.isVolatileQualified());
370 
371   // If this is a postinc, return the value read from memory, otherwise use the
372   // updated value.
373   return isPre ? IncVal : InVal;
374 }
375 
376 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
377   TestAndClearIgnoreReal();
378   TestAndClearIgnoreImag();
379   TestAndClearIgnoreRealAssign();
380   TestAndClearIgnoreImagAssign();
381   ComplexPairTy Op = Visit(E->getSubExpr());
382   llvm::Value *ResR = Builder.CreateNeg(Op.first,  "neg.r");
383   llvm::Value *ResI = Builder.CreateNeg(Op.second, "neg.i");
384   return ComplexPairTy(ResR, ResI);
385 }
386 
387 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
388   TestAndClearIgnoreReal();
389   TestAndClearIgnoreImag();
390   TestAndClearIgnoreRealAssign();
391   TestAndClearIgnoreImagAssign();
392   // ~(a+ib) = a + i*-b
393   ComplexPairTy Op = Visit(E->getSubExpr());
394   llvm::Value *ResI = Builder.CreateNeg(Op.second, "conj.i");
395   return ComplexPairTy(Op.first, ResI);
396 }
397 
398 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
399   llvm::Value *ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
400   llvm::Value *ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
401   return ComplexPairTy(ResR, ResI);
402 }
403 
404 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
405   llvm::Value *ResR = Builder.CreateSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
406   llvm::Value *ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
407   return ComplexPairTy(ResR, ResI);
408 }
409 
410 
411 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
412   llvm::Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
413   llvm::Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
414   llvm::Value *ResR  = Builder.CreateSub(ResRl, ResRr, "mul.r");
415 
416   llvm::Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
417   llvm::Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
418   llvm::Value *ResI  = Builder.CreateAdd(ResIl, ResIr, "mul.i");
419   return ComplexPairTy(ResR, ResI);
420 }
421 
422 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
423   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
424   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
425 
426   // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
427   llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr, "tmp"); // a*c
428   llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi, "tmp"); // b*d
429   llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2, "tmp"); // ac+bd
430 
431   llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr, "tmp"); // c*c
432   llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi, "tmp"); // d*d
433   llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5, "tmp"); // cc+dd
434 
435   llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr, "tmp"); // b*c
436   llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi, "tmp"); // a*d
437   llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8, "tmp"); // bc-ad
438 
439   llvm::Value *DSTr, *DSTi;
440   if (Tmp3->getType()->isFloatingPoint()) {
441     DSTr = Builder.CreateFDiv(Tmp3, Tmp6, "tmp");
442     DSTi = Builder.CreateFDiv(Tmp9, Tmp6, "tmp");
443   } else {
444     if (Op.Ty->getAsComplexType()->getElementType()->isUnsignedIntegerType()) {
445       DSTr = Builder.CreateUDiv(Tmp3, Tmp6, "tmp");
446       DSTi = Builder.CreateUDiv(Tmp9, Tmp6, "tmp");
447     } else {
448       DSTr = Builder.CreateSDiv(Tmp3, Tmp6, "tmp");
449       DSTi = Builder.CreateSDiv(Tmp9, Tmp6, "tmp");
450     }
451   }
452 
453   return ComplexPairTy(DSTr, DSTi);
454 }
455 
456 ComplexExprEmitter::BinOpInfo
457 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
458   TestAndClearIgnoreReal();
459   TestAndClearIgnoreImag();
460   TestAndClearIgnoreRealAssign();
461   TestAndClearIgnoreImagAssign();
462   BinOpInfo Ops;
463   Ops.LHS = Visit(E->getLHS());
464   Ops.RHS = Visit(E->getRHS());
465   Ops.Ty = E->getType();
466   return Ops;
467 }
468 
469 
470 // Compound assignments.
471 ComplexPairTy ComplexExprEmitter::
472 EmitCompoundAssign(const CompoundAssignOperator *E,
473                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
474   TestAndClearIgnoreReal();
475   TestAndClearIgnoreImag();
476   bool ignreal = TestAndClearIgnoreRealAssign();
477   bool ignimag = TestAndClearIgnoreImagAssign();
478   QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType();
479 
480   BinOpInfo OpInfo;
481 
482   // Load the RHS and LHS operands.
483   // __block variables need to have the rhs evaluated first, plus this should
484   // improve codegen a little.  It is possible for the RHS to be complex or
485   // scalar.
486   OpInfo.Ty = E->getComputationResultType();
487   OpInfo.RHS = EmitCast(E->getRHS(), OpInfo.Ty);
488 
489   LValue LHSLV = CGF.EmitLValue(E->getLHS());
490 
491 
492   // We know the LHS is a complex lvalue.
493   OpInfo.LHS=EmitLoadOfComplex(LHSLV.getAddress(),LHSLV.isVolatileQualified());
494   OpInfo.LHS=EmitComplexToComplexCast(OpInfo.LHS, LHSTy, OpInfo.Ty);
495 
496   // Expand the binary operator.
497   ComplexPairTy Result = (this->*Func)(OpInfo);
498 
499   // Truncate the result back to the LHS type.
500   Result = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
501 
502   // Store the result value into the LHS lvalue.
503   EmitStoreOfComplex(Result, LHSLV.getAddress(), LHSLV.isVolatileQualified());
504   // And now return the LHS
505   IgnoreReal = ignreal;
506   IgnoreImag = ignimag;
507   IgnoreRealAssign = ignreal;
508   IgnoreImagAssign = ignimag;
509   return EmitLoadOfComplex(LHSLV.getAddress(), LHSLV.isVolatileQualified());
510 }
511 
512 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
513   TestAndClearIgnoreReal();
514   TestAndClearIgnoreImag();
515   bool ignreal = TestAndClearIgnoreRealAssign();
516   bool ignimag = TestAndClearIgnoreImagAssign();
517   assert(CGF.getContext().getCanonicalType(E->getLHS()->getType()) ==
518          CGF.getContext().getCanonicalType(E->getRHS()->getType()) &&
519          "Invalid assignment");
520   // Emit the RHS.
521   ComplexPairTy Val = Visit(E->getRHS());
522 
523   // Compute the address to store into.
524   LValue LHS = CGF.EmitLValue(E->getLHS());
525 
526   // Store into it.
527   EmitStoreOfComplex(Val, LHS.getAddress(), LHS.isVolatileQualified());
528   // And now return the LHS
529   IgnoreReal = ignreal;
530   IgnoreImag = ignimag;
531   IgnoreRealAssign = ignreal;
532   IgnoreImagAssign = ignimag;
533   return EmitLoadOfComplex(LHS.getAddress(), LHS.isVolatileQualified());
534 }
535 
536 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
537   CGF.EmitStmt(E->getLHS());
538   CGF.EnsureInsertPoint();
539   return Visit(E->getRHS());
540 }
541 
542 ComplexPairTy ComplexExprEmitter::
543 VisitConditionalOperator(const ConditionalOperator *E) {
544   TestAndClearIgnoreReal();
545   TestAndClearIgnoreImag();
546   TestAndClearIgnoreRealAssign();
547   TestAndClearIgnoreImagAssign();
548   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
549   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
550   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
551 
552   llvm::Value *Cond = CGF.EvaluateExprAsBool(E->getCond());
553   Builder.CreateCondBr(Cond, LHSBlock, RHSBlock);
554 
555   CGF.EmitBlock(LHSBlock);
556 
557   // Handle the GNU extension for missing LHS.
558   assert(E->getLHS() && "Must have LHS for complex value");
559 
560   ComplexPairTy LHS = Visit(E->getLHS());
561   LHSBlock = Builder.GetInsertBlock();
562   CGF.EmitBranch(ContBlock);
563 
564   CGF.EmitBlock(RHSBlock);
565 
566   ComplexPairTy RHS = Visit(E->getRHS());
567   RHSBlock = Builder.GetInsertBlock();
568   CGF.EmitBranch(ContBlock);
569 
570   CGF.EmitBlock(ContBlock);
571 
572   // Create a PHI node for the real part.
573   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), "cond.r");
574   RealPN->reserveOperandSpace(2);
575   RealPN->addIncoming(LHS.first, LHSBlock);
576   RealPN->addIncoming(RHS.first, RHSBlock);
577 
578   // Create a PHI node for the imaginary part.
579   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), "cond.i");
580   ImagPN->reserveOperandSpace(2);
581   ImagPN->addIncoming(LHS.second, LHSBlock);
582   ImagPN->addIncoming(RHS.second, RHSBlock);
583 
584   return ComplexPairTy(RealPN, ImagPN);
585 }
586 
587 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
588   return Visit(E->getChosenSubExpr(CGF.getContext()));
589 }
590 
591 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
592     bool Ignore = TestAndClearIgnoreReal();
593     (void)Ignore;
594     assert (Ignore == false && "init list ignored");
595     Ignore = TestAndClearIgnoreImag();
596     (void)Ignore;
597     assert (Ignore == false && "init list ignored");
598   if (E->getNumInits())
599     return Visit(E->getInit(0));
600 
601   // Empty init list intializes to null
602   QualType Ty = E->getType()->getAsComplexType()->getElementType();
603   const llvm::Type* LTy = CGF.ConvertType(Ty);
604   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
605   return ComplexPairTy(zeroConstant, zeroConstant);
606 }
607 
608 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
609   llvm::Value *ArgValue = CGF.EmitVAListRef(E->getSubExpr());
610   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, E->getType());
611 
612   if (!ArgPtr) {
613     CGF.ErrorUnsupported(E, "complex va_arg expression");
614     const llvm::Type *EltTy =
615       CGF.ConvertType(E->getType()->getAsComplexType()->getElementType());
616     llvm::Value *U = llvm::UndefValue::get(EltTy);
617     return ComplexPairTy(U, U);
618   }
619 
620   // FIXME Volatility.
621   return EmitLoadOfComplex(ArgPtr, false);
622 }
623 
624 //===----------------------------------------------------------------------===//
625 //                         Entry Point into this File
626 //===----------------------------------------------------------------------===//
627 
628 /// EmitComplexExpr - Emit the computation of the specified expression of
629 /// complex type, ignoring the result.
630 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
631                                                bool IgnoreImag, bool IgnoreRealAssign, bool IgnoreImagAssign) {
632   assert(E && E->getType()->isAnyComplexType() &&
633          "Invalid complex expression to emit");
634 
635   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag, IgnoreRealAssign,
636                             IgnoreImagAssign)
637     .Visit(const_cast<Expr*>(E));
638 }
639 
640 /// EmitComplexExprIntoAddr - Emit the computation of the specified expression
641 /// of complex type, storing into the specified Value*.
642 void CodeGenFunction::EmitComplexExprIntoAddr(const Expr *E,
643                                               llvm::Value *DestAddr,
644                                               bool DestIsVolatile) {
645   assert(E && E->getType()->isAnyComplexType() &&
646          "Invalid complex expression to emit");
647   ComplexExprEmitter Emitter(*this);
648   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
649   Emitter.EmitStoreOfComplex(Val, DestAddr, DestIsVolatile);
650 }
651 
652 /// StoreComplexToAddr - Store a complex number into the specified address.
653 void CodeGenFunction::StoreComplexToAddr(ComplexPairTy V,
654                                          llvm::Value *DestAddr,
655                                          bool DestIsVolatile) {
656   ComplexExprEmitter(*this).EmitStoreOfComplex(V, DestAddr, DestIsVolatile);
657 }
658 
659 /// LoadComplexFromAddr - Load a complex number from the specified address.
660 ComplexPairTy CodeGenFunction::LoadComplexFromAddr(llvm::Value *SrcAddr,
661                                                    bool SrcIsVolatile) {
662   return ComplexExprEmitter(*this).EmitLoadOfComplex(SrcAddr, SrcIsVolatile);
663 }
664