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 using namespace clang;
22 using namespace CodeGen;
23 
24 //===----------------------------------------------------------------------===//
25 //                        Complex Expression Emitter
26 //===----------------------------------------------------------------------===//
27 
28 typedef CodeGenFunction::ComplexPairTy ComplexPairTy;
29 
30 namespace  {
31 class ComplexExprEmitter
32   : public StmtVisitor<ComplexExprEmitter, ComplexPairTy> {
33   CodeGenFunction &CGF;
34   CGBuilderTy &Builder;
35   // True is we should ignore the value of a
36   bool IgnoreReal;
37   bool IgnoreImag;
38 public:
39   ComplexExprEmitter(CodeGenFunction &cgf, bool ir=false, bool ii=false)
40     : CGF(cgf), Builder(CGF.Builder), IgnoreReal(ir), IgnoreImag(ii) {
41   }
42 
43 
44   //===--------------------------------------------------------------------===//
45   //                               Utilities
46   //===--------------------------------------------------------------------===//
47 
48   bool TestAndClearIgnoreReal() {
49     bool I = IgnoreReal;
50     IgnoreReal = false;
51     return I;
52   }
53   bool TestAndClearIgnoreImag() {
54     bool I = IgnoreImag;
55     IgnoreImag = false;
56     return I;
57   }
58 
59   /// EmitLoadOfLValue - Given an expression with complex type that represents a
60   /// value l-value, this method emits the address of the l-value, then loads
61   /// and returns the result.
62   ComplexPairTy EmitLoadOfLValue(const Expr *E) {
63     return EmitLoadOfLValue(CGF.EmitLValue(E));
64   }
65 
66   ComplexPairTy EmitLoadOfLValue(LValue LV) {
67     if (LV.isSimple())
68       return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
69 
70     assert(LV.isPropertyRef() && "Unknown LValue type!");
71     return CGF.EmitLoadOfPropertyRefLValue(LV).getComplexVal();
72   }
73 
74   /// EmitLoadOfComplex - Given a pointer to a complex value, emit code to load
75   /// the real and imaginary pieces.
76   ComplexPairTy EmitLoadOfComplex(llvm::Value *SrcPtr, bool isVolatile);
77 
78   /// EmitStoreThroughLValue - Given an l-value of complex type, store
79   /// a complex number into it.
80   void EmitStoreThroughLValue(ComplexPairTy Val, LValue LV) {
81     if (LV.isSimple())
82       return EmitStoreOfComplex(Val, LV.getAddress(), LV.isVolatileQualified());
83 
84     assert(LV.isPropertyRef() && "Unknown LValue type!");
85     CGF.EmitStoreThroughPropertyRefLValue(RValue::getComplex(Val), LV);
86   }
87 
88   /// EmitStoreOfComplex - Store the specified real/imag parts into the
89   /// specified value pointer.
90   void EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *ResPtr, bool isVol);
91 
92   /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
93   ComplexPairTy EmitComplexToComplexCast(ComplexPairTy Val, QualType SrcType,
94                                          QualType DestType);
95 
96   //===--------------------------------------------------------------------===//
97   //                            Visitor Methods
98   //===--------------------------------------------------------------------===//
99 
100   ComplexPairTy Visit(Expr *E) {
101     return StmtVisitor<ComplexExprEmitter, ComplexPairTy>::Visit(E);
102   }
103 
104   ComplexPairTy VisitStmt(Stmt *S) {
105     S->dump(CGF.getContext().getSourceManager());
106     assert(0 && "Stmt can't have complex result type!");
107     return ComplexPairTy();
108   }
109   ComplexPairTy VisitExpr(Expr *S);
110   ComplexPairTy VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr());}
111   ComplexPairTy VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
112     return Visit(GE->getResultExpr());
113   }
114   ComplexPairTy VisitImaginaryLiteral(const ImaginaryLiteral *IL);
115   ComplexPairTy
116   VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *PE) {
117     return Visit(PE->getReplacement());
118   }
119 
120   // l-values.
121   ComplexPairTy VisitDeclRefExpr(const Expr *E) { return EmitLoadOfLValue(E); }
122   ComplexPairTy VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
123     return EmitLoadOfLValue(E);
124   }
125   ComplexPairTy VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
126     assert(E->getObjectKind() == OK_Ordinary);
127     return EmitLoadOfLValue(E);
128   }
129   ComplexPairTy VisitObjCMessageExpr(ObjCMessageExpr *E) {
130     return CGF.EmitObjCMessageExpr(E).getComplexVal();
131   }
132   ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
133   ComplexPairTy VisitMemberExpr(const Expr *E) { return EmitLoadOfLValue(E); }
134   ComplexPairTy VisitOpaqueValueExpr(OpaqueValueExpr *E) {
135     if (E->isGLValue())
136       return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E));
137     return CGF.getOpaqueRValueMapping(E).getComplexVal();
138   }
139 
140   // FIXME: CompoundLiteralExpr
141 
142   ComplexPairTy EmitCast(CastExpr::CastKind CK, Expr *Op, QualType DestTy);
143   ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
144     // Unlike for scalars, we don't have to worry about function->ptr demotion
145     // here.
146     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
147   }
148   ComplexPairTy VisitCastExpr(CastExpr *E) {
149     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
150   }
151   ComplexPairTy VisitCallExpr(const CallExpr *E);
152   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
153 
154   // Operators.
155   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
156                                    bool isInc, bool isPre) {
157     LValue LV = CGF.EmitLValue(E->getSubExpr());
158     return CGF.EmitComplexPrePostIncDec(E, LV, isInc, isPre);
159   }
160   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
161     return VisitPrePostIncDec(E, false, false);
162   }
163   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
164     return VisitPrePostIncDec(E, true, false);
165   }
166   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
167     return VisitPrePostIncDec(E, false, true);
168   }
169   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
170     return VisitPrePostIncDec(E, true, true);
171   }
172   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
173   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
174     TestAndClearIgnoreReal();
175     TestAndClearIgnoreImag();
176     return Visit(E->getSubExpr());
177   }
178   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
179   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
180   // LNot,Real,Imag never return complex.
181   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
182     return Visit(E->getSubExpr());
183   }
184   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
185     return Visit(DAE->getExpr());
186   }
187   ComplexPairTy VisitExprWithCleanups(ExprWithCleanups *E) {
188     return CGF.EmitExprWithCleanups(E).getComplexVal();
189   }
190   ComplexPairTy VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
191     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
192     QualType Elem = E->getType()->getAs<ComplexType>()->getElementType();
193     llvm::Constant *Null = llvm::Constant::getNullValue(CGF.ConvertType(Elem));
194     return ComplexPairTy(Null, Null);
195   }
196   ComplexPairTy VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
197     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
198     QualType Elem = E->getType()->getAs<ComplexType>()->getElementType();
199     llvm::Constant *Null =
200                        llvm::Constant::getNullValue(CGF.ConvertType(Elem));
201     return ComplexPairTy(Null, Null);
202   }
203 
204   struct BinOpInfo {
205     ComplexPairTy LHS;
206     ComplexPairTy RHS;
207     QualType Ty;  // Computation Type.
208   };
209 
210   BinOpInfo EmitBinOps(const BinaryOperator *E);
211   LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
212                                   ComplexPairTy (ComplexExprEmitter::*Func)
213                                   (const BinOpInfo &),
214                                   ComplexPairTy &Val);
215   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
216                                    ComplexPairTy (ComplexExprEmitter::*Func)
217                                    (const BinOpInfo &));
218 
219   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
220   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
221   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
222   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
223 
224   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
225     return EmitBinAdd(EmitBinOps(E));
226   }
227   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
228     return EmitBinSub(EmitBinOps(E));
229   }
230   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
231     return EmitBinMul(EmitBinOps(E));
232   }
233   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
234     return EmitBinDiv(EmitBinOps(E));
235   }
236 
237   // Compound assignments.
238   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
239     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
240   }
241   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
242     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
243   }
244   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
245     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
246   }
247   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
248     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
249   }
250 
251   // GCC rejects rem/and/or/xor for integer complex.
252   // Logical and/or always return int, never complex.
253 
254   // No comparisons produce a complex result.
255 
256   LValue EmitBinAssignLValue(const BinaryOperator *E,
257                              ComplexPairTy &Val);
258   ComplexPairTy VisitBinAssign     (const BinaryOperator *E);
259   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
260 
261 
262   ComplexPairTy
263   VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
264   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
265 
266   ComplexPairTy VisitInitListExpr(InitListExpr *E);
267 
268   ComplexPairTy VisitVAArgExpr(VAArgExpr *E);
269 };
270 }  // end anonymous namespace.
271 
272 //===----------------------------------------------------------------------===//
273 //                                Utilities
274 //===----------------------------------------------------------------------===//
275 
276 /// EmitLoadOfComplex - Given an RValue reference for a complex, emit code to
277 /// load the real and imaginary pieces, returning them as Real/Imag.
278 ComplexPairTy ComplexExprEmitter::EmitLoadOfComplex(llvm::Value *SrcPtr,
279                                                     bool isVolatile) {
280   llvm::Value *Real=0, *Imag=0;
281 
282   if (!IgnoreReal || isVolatile) {
283     llvm::Value *RealP = Builder.CreateStructGEP(SrcPtr, 0,
284                                                  SrcPtr->getName() + ".realp");
285     Real = Builder.CreateLoad(RealP, isVolatile, SrcPtr->getName() + ".real");
286   }
287 
288   if (!IgnoreImag || isVolatile) {
289     llvm::Value *ImagP = Builder.CreateStructGEP(SrcPtr, 1,
290                                                  SrcPtr->getName() + ".imagp");
291     Imag = Builder.CreateLoad(ImagP, isVolatile, SrcPtr->getName() + ".imag");
292   }
293   return ComplexPairTy(Real, Imag);
294 }
295 
296 /// EmitStoreOfComplex - Store the specified real/imag parts into the
297 /// specified value pointer.
298 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *Ptr,
299                                             bool isVolatile) {
300   llvm::Value *RealPtr = Builder.CreateStructGEP(Ptr, 0, "real");
301   llvm::Value *ImagPtr = Builder.CreateStructGEP(Ptr, 1, "imag");
302 
303   Builder.CreateStore(Val.first, RealPtr, isVolatile);
304   Builder.CreateStore(Val.second, ImagPtr, isVolatile);
305 }
306 
307 
308 
309 //===----------------------------------------------------------------------===//
310 //                            Visitor Methods
311 //===----------------------------------------------------------------------===//
312 
313 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
314   return EmitLoadOfLValue(E);
315 }
316 
317 ComplexPairTy ComplexExprEmitter::
318 VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
319   llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
320   return ComplexPairTy(llvm::Constant::getNullValue(Imag->getType()), Imag);
321 }
322 
323 
324 ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
325   if (E->getCallReturnType()->isReferenceType())
326     return EmitLoadOfLValue(E);
327 
328   return CGF.EmitCallExpr(E).getComplexVal();
329 }
330 
331 ComplexPairTy ComplexExprEmitter::VisitStmtExpr(const StmtExpr *E) {
332   CodeGenFunction::StmtExprEvaluation eval(CGF);
333   return CGF.EmitCompoundStmt(*E->getSubStmt(), true).getComplexVal();
334 }
335 
336 /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
337 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
338                                                            QualType SrcType,
339                                                            QualType DestType) {
340   // Get the src/dest element type.
341   SrcType = SrcType->getAs<ComplexType>()->getElementType();
342   DestType = DestType->getAs<ComplexType>()->getElementType();
343 
344   // C99 6.3.1.6: When a value of complex type is converted to another
345   // complex type, both the real and imaginary parts follow the conversion
346   // rules for the corresponding real types.
347   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType);
348   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType);
349   return Val;
350 }
351 
352 ComplexPairTy ComplexExprEmitter::EmitCast(CastExpr::CastKind CK, Expr *Op,
353                                            QualType DestTy) {
354   switch (CK) {
355   case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!");
356 
357   case CK_GetObjCProperty: {
358     LValue LV = CGF.EmitLValue(Op);
359     assert(LV.isPropertyRef() && "Unknown LValue type!");
360     return CGF.EmitLoadOfPropertyRefLValue(LV).getComplexVal();
361   }
362 
363   case CK_NoOp:
364   case CK_LValueToRValue:
365   case CK_UserDefinedConversion:
366     return Visit(Op);
367 
368   case CK_LValueBitCast: {
369     llvm::Value *V = CGF.EmitLValue(Op).getAddress();
370     V = Builder.CreateBitCast(V,
371                     CGF.ConvertType(CGF.getContext().getPointerType(DestTy)));
372     // FIXME: Are the qualifiers correct here?
373     return EmitLoadOfComplex(V, DestTy.isVolatileQualified());
374   }
375 
376   case CK_BitCast:
377   case CK_BaseToDerived:
378   case CK_DerivedToBase:
379   case CK_UncheckedDerivedToBase:
380   case CK_Dynamic:
381   case CK_ToUnion:
382   case CK_ArrayToPointerDecay:
383   case CK_FunctionToPointerDecay:
384   case CK_NullToPointer:
385   case CK_NullToMemberPointer:
386   case CK_BaseToDerivedMemberPointer:
387   case CK_DerivedToBaseMemberPointer:
388   case CK_MemberPointerToBoolean:
389   case CK_ConstructorConversion:
390   case CK_IntegralToPointer:
391   case CK_PointerToIntegral:
392   case CK_PointerToBoolean:
393   case CK_ToVoid:
394   case CK_VectorSplat:
395   case CK_IntegralCast:
396   case CK_IntegralToBoolean:
397   case CK_IntegralToFloating:
398   case CK_FloatingToIntegral:
399   case CK_FloatingToBoolean:
400   case CK_FloatingCast:
401   case CK_AnyPointerToObjCPointerCast:
402   case CK_AnyPointerToBlockPointerCast:
403   case CK_ObjCObjectLValueCast:
404   case CK_FloatingComplexToReal:
405   case CK_FloatingComplexToBoolean:
406   case CK_IntegralComplexToReal:
407   case CK_IntegralComplexToBoolean:
408   case CK_ObjCProduceObject:
409   case CK_ObjCConsumeObject:
410   case CK_ObjCReclaimReturnedObject:
411     llvm_unreachable("invalid cast kind for complex value");
412 
413   case CK_FloatingRealToComplex:
414   case CK_IntegralRealToComplex: {
415     llvm::Value *Elt = CGF.EmitScalarExpr(Op);
416 
417     // Convert the input element to the element type of the complex.
418     DestTy = DestTy->getAs<ComplexType>()->getElementType();
419     Elt = CGF.EmitScalarConversion(Elt, Op->getType(), DestTy);
420 
421     // Return (realval, 0).
422     return ComplexPairTy(Elt, llvm::Constant::getNullValue(Elt->getType()));
423   }
424 
425   case CK_FloatingComplexCast:
426   case CK_FloatingComplexToIntegralComplex:
427   case CK_IntegralComplexCast:
428   case CK_IntegralComplexToFloatingComplex:
429     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
430   }
431 
432   llvm_unreachable("unknown cast resulting in complex value");
433 }
434 
435 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
436   TestAndClearIgnoreReal();
437   TestAndClearIgnoreImag();
438   ComplexPairTy Op = Visit(E->getSubExpr());
439 
440   llvm::Value *ResR, *ResI;
441   if (Op.first->getType()->isFloatingPointTy()) {
442     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
443     ResI = Builder.CreateFNeg(Op.second, "neg.i");
444   } else {
445     ResR = Builder.CreateNeg(Op.first,  "neg.r");
446     ResI = Builder.CreateNeg(Op.second, "neg.i");
447   }
448   return ComplexPairTy(ResR, ResI);
449 }
450 
451 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
452   TestAndClearIgnoreReal();
453   TestAndClearIgnoreImag();
454   // ~(a+ib) = a + i*-b
455   ComplexPairTy Op = Visit(E->getSubExpr());
456   llvm::Value *ResI;
457   if (Op.second->getType()->isFloatingPointTy())
458     ResI = Builder.CreateFNeg(Op.second, "conj.i");
459   else
460     ResI = Builder.CreateNeg(Op.second, "conj.i");
461 
462   return ComplexPairTy(Op.first, ResI);
463 }
464 
465 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
466   llvm::Value *ResR, *ResI;
467 
468   if (Op.LHS.first->getType()->isFloatingPointTy()) {
469     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
470     ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
471   } else {
472     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
473     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
474   }
475   return ComplexPairTy(ResR, ResI);
476 }
477 
478 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
479   llvm::Value *ResR, *ResI;
480   if (Op.LHS.first->getType()->isFloatingPointTy()) {
481     ResR = Builder.CreateFSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
482     ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
483   } else {
484     ResR = Builder.CreateSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
485     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
486   }
487   return ComplexPairTy(ResR, ResI);
488 }
489 
490 
491 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
492   using llvm::Value;
493   Value *ResR, *ResI;
494 
495   if (Op.LHS.first->getType()->isFloatingPointTy()) {
496     Value *ResRl = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
497     Value *ResRr = Builder.CreateFMul(Op.LHS.second, Op.RHS.second,"mul.rr");
498     ResR  = Builder.CreateFSub(ResRl, ResRr, "mul.r");
499 
500     Value *ResIl = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il");
501     Value *ResIr = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
502     ResI  = Builder.CreateFAdd(ResIl, ResIr, "mul.i");
503   } else {
504     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
505     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
506     ResR  = Builder.CreateSub(ResRl, ResRr, "mul.r");
507 
508     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
509     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
510     ResI  = Builder.CreateAdd(ResIl, ResIr, "mul.i");
511   }
512   return ComplexPairTy(ResR, ResI);
513 }
514 
515 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
516   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
517   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
518 
519 
520   llvm::Value *DSTr, *DSTi;
521   if (Op.LHS.first->getType()->isFloatingPointTy()) {
522     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
523     llvm::Value *Tmp1 = Builder.CreateFMul(LHSr, RHSr, "tmp"); // a*c
524     llvm::Value *Tmp2 = Builder.CreateFMul(LHSi, RHSi, "tmp"); // b*d
525     llvm::Value *Tmp3 = Builder.CreateFAdd(Tmp1, Tmp2, "tmp"); // ac+bd
526 
527     llvm::Value *Tmp4 = Builder.CreateFMul(RHSr, RHSr, "tmp"); // c*c
528     llvm::Value *Tmp5 = Builder.CreateFMul(RHSi, RHSi, "tmp"); // d*d
529     llvm::Value *Tmp6 = Builder.CreateFAdd(Tmp4, Tmp5, "tmp"); // cc+dd
530 
531     llvm::Value *Tmp7 = Builder.CreateFMul(LHSi, RHSr, "tmp"); // b*c
532     llvm::Value *Tmp8 = Builder.CreateFMul(LHSr, RHSi, "tmp"); // a*d
533     llvm::Value *Tmp9 = Builder.CreateFSub(Tmp7, Tmp8, "tmp"); // bc-ad
534 
535     DSTr = Builder.CreateFDiv(Tmp3, Tmp6, "tmp");
536     DSTi = Builder.CreateFDiv(Tmp9, Tmp6, "tmp");
537   } else {
538     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
539     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr, "tmp"); // a*c
540     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi, "tmp"); // b*d
541     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2, "tmp"); // ac+bd
542 
543     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr, "tmp"); // c*c
544     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi, "tmp"); // d*d
545     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5, "tmp"); // cc+dd
546 
547     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr, "tmp"); // b*c
548     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi, "tmp"); // a*d
549     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8, "tmp"); // bc-ad
550 
551     if (Op.Ty->getAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
552       DSTr = Builder.CreateUDiv(Tmp3, Tmp6, "tmp");
553       DSTi = Builder.CreateUDiv(Tmp9, Tmp6, "tmp");
554     } else {
555       DSTr = Builder.CreateSDiv(Tmp3, Tmp6, "tmp");
556       DSTi = Builder.CreateSDiv(Tmp9, Tmp6, "tmp");
557     }
558   }
559 
560   return ComplexPairTy(DSTr, DSTi);
561 }
562 
563 ComplexExprEmitter::BinOpInfo
564 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
565   TestAndClearIgnoreReal();
566   TestAndClearIgnoreImag();
567   BinOpInfo Ops;
568   Ops.LHS = Visit(E->getLHS());
569   Ops.RHS = Visit(E->getRHS());
570   Ops.Ty = E->getType();
571   return Ops;
572 }
573 
574 
575 LValue ComplexExprEmitter::
576 EmitCompoundAssignLValue(const CompoundAssignOperator *E,
577           ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&),
578                          ComplexPairTy &Val) {
579   TestAndClearIgnoreReal();
580   TestAndClearIgnoreImag();
581   QualType LHSTy = E->getLHS()->getType();
582 
583   BinOpInfo OpInfo;
584 
585   // Load the RHS and LHS operands.
586   // __block variables need to have the rhs evaluated first, plus this should
587   // improve codegen a little.
588   OpInfo.Ty = E->getComputationResultType();
589 
590   // The RHS should have been converted to the computation type.
591   assert(OpInfo.Ty->isAnyComplexType());
592   assert(CGF.getContext().hasSameUnqualifiedType(OpInfo.Ty,
593                                                  E->getRHS()->getType()));
594   OpInfo.RHS = Visit(E->getRHS());
595 
596   LValue LHS = CGF.EmitLValue(E->getLHS());
597 
598   // Load from the l-value.
599   ComplexPairTy LHSComplexPair = EmitLoadOfLValue(LHS);
600 
601   OpInfo.LHS = EmitComplexToComplexCast(LHSComplexPair, LHSTy, OpInfo.Ty);
602 
603   // Expand the binary operator.
604   ComplexPairTy Result = (this->*Func)(OpInfo);
605 
606   // Truncate the result back to the LHS type.
607   Result = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
608   Val = Result;
609 
610   // Store the result value into the LHS lvalue.
611   EmitStoreThroughLValue(Result, LHS);
612 
613   return LHS;
614 }
615 
616 // Compound assignments.
617 ComplexPairTy ComplexExprEmitter::
618 EmitCompoundAssign(const CompoundAssignOperator *E,
619                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
620   ComplexPairTy Val;
621   LValue LV = EmitCompoundAssignLValue(E, Func, Val);
622 
623   // The result of an assignment in C is the assigned r-value.
624   if (!CGF.getContext().getLangOptions().CPlusPlus)
625     return Val;
626 
627   // Objective-C property assignment never reloads the value following a store.
628   if (LV.isPropertyRef())
629     return Val;
630 
631   // If the lvalue is non-volatile, return the computed value of the assignment.
632   if (!LV.isVolatileQualified())
633     return Val;
634 
635   return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
636 }
637 
638 LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
639                                                ComplexPairTy &Val) {
640   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
641                                                  E->getRHS()->getType()) &&
642          "Invalid assignment");
643   TestAndClearIgnoreReal();
644   TestAndClearIgnoreImag();
645 
646   // Emit the RHS.  __block variables need the RHS evaluated first.
647   Val = Visit(E->getRHS());
648 
649   // Compute the address to store into.
650   LValue LHS = CGF.EmitLValue(E->getLHS());
651 
652   // Store the result value into the LHS lvalue.
653   EmitStoreThroughLValue(Val, LHS);
654 
655   return LHS;
656 }
657 
658 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
659   ComplexPairTy Val;
660   LValue LV = EmitBinAssignLValue(E, Val);
661 
662   // The result of an assignment in C is the assigned r-value.
663   if (!CGF.getContext().getLangOptions().CPlusPlus)
664     return Val;
665 
666   // Objective-C property assignment never reloads the value following a store.
667   if (LV.isPropertyRef())
668     return Val;
669 
670   // If the lvalue is non-volatile, return the computed value of the assignment.
671   if (!LV.isVolatileQualified())
672     return Val;
673 
674   return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
675 }
676 
677 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
678   CGF.EmitIgnoredExpr(E->getLHS());
679   return Visit(E->getRHS());
680 }
681 
682 ComplexPairTy ComplexExprEmitter::
683 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
684   TestAndClearIgnoreReal();
685   TestAndClearIgnoreImag();
686   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
687   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
688   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
689 
690   // Bind the common expression if necessary.
691   CodeGenFunction::OpaqueValueMapping binding(CGF, E);
692 
693   CodeGenFunction::ConditionalEvaluation eval(CGF);
694   CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
695 
696   eval.begin(CGF);
697   CGF.EmitBlock(LHSBlock);
698   ComplexPairTy LHS = Visit(E->getTrueExpr());
699   LHSBlock = Builder.GetInsertBlock();
700   CGF.EmitBranch(ContBlock);
701   eval.end(CGF);
702 
703   eval.begin(CGF);
704   CGF.EmitBlock(RHSBlock);
705   ComplexPairTy RHS = Visit(E->getFalseExpr());
706   RHSBlock = Builder.GetInsertBlock();
707   CGF.EmitBlock(ContBlock);
708   eval.end(CGF);
709 
710   // Create a PHI node for the real part.
711   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.r");
712   RealPN->addIncoming(LHS.first, LHSBlock);
713   RealPN->addIncoming(RHS.first, RHSBlock);
714 
715   // Create a PHI node for the imaginary part.
716   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.i");
717   ImagPN->addIncoming(LHS.second, LHSBlock);
718   ImagPN->addIncoming(RHS.second, RHSBlock);
719 
720   return ComplexPairTy(RealPN, ImagPN);
721 }
722 
723 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
724   return Visit(E->getChosenSubExpr(CGF.getContext()));
725 }
726 
727 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
728     bool Ignore = TestAndClearIgnoreReal();
729     (void)Ignore;
730     assert (Ignore == false && "init list ignored");
731     Ignore = TestAndClearIgnoreImag();
732     (void)Ignore;
733     assert (Ignore == false && "init list ignored");
734   if (E->getNumInits())
735     return Visit(E->getInit(0));
736 
737   // Empty init list intializes to null
738   QualType Ty = E->getType()->getAs<ComplexType>()->getElementType();
739   llvm::Type* LTy = CGF.ConvertType(Ty);
740   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
741   return ComplexPairTy(zeroConstant, zeroConstant);
742 }
743 
744 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
745   llvm::Value *ArgValue = CGF.EmitVAListRef(E->getSubExpr());
746   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, E->getType());
747 
748   if (!ArgPtr) {
749     CGF.ErrorUnsupported(E, "complex va_arg expression");
750     llvm::Type *EltTy =
751       CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
752     llvm::Value *U = llvm::UndefValue::get(EltTy);
753     return ComplexPairTy(U, U);
754   }
755 
756   // FIXME Volatility.
757   return EmitLoadOfComplex(ArgPtr, false);
758 }
759 
760 //===----------------------------------------------------------------------===//
761 //                         Entry Point into this File
762 //===----------------------------------------------------------------------===//
763 
764 /// EmitComplexExpr - Emit the computation of the specified expression of
765 /// complex type, ignoring the result.
766 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
767                                                bool IgnoreImag) {
768   assert(E && E->getType()->isAnyComplexType() &&
769          "Invalid complex expression to emit");
770 
771   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag)
772     .Visit(const_cast<Expr*>(E));
773 }
774 
775 /// EmitComplexExprIntoAddr - Emit the computation of the specified expression
776 /// of complex type, storing into the specified Value*.
777 void CodeGenFunction::EmitComplexExprIntoAddr(const Expr *E,
778                                               llvm::Value *DestAddr,
779                                               bool DestIsVolatile) {
780   assert(E && E->getType()->isAnyComplexType() &&
781          "Invalid complex expression to emit");
782   ComplexExprEmitter Emitter(*this);
783   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
784   Emitter.EmitStoreOfComplex(Val, DestAddr, DestIsVolatile);
785 }
786 
787 /// StoreComplexToAddr - Store a complex number into the specified address.
788 void CodeGenFunction::StoreComplexToAddr(ComplexPairTy V,
789                                          llvm::Value *DestAddr,
790                                          bool DestIsVolatile) {
791   ComplexExprEmitter(*this).EmitStoreOfComplex(V, DestAddr, DestIsVolatile);
792 }
793 
794 /// LoadComplexFromAddr - Load a complex number from the specified address.
795 ComplexPairTy CodeGenFunction::LoadComplexFromAddr(llvm::Value *SrcAddr,
796                                                    bool SrcIsVolatile) {
797   return ComplexExprEmitter(*this).EmitLoadOfComplex(SrcAddr, SrcIsVolatile);
798 }
799 
800 LValue CodeGenFunction::EmitComplexAssignmentLValue(const BinaryOperator *E) {
801   assert(E->getOpcode() == BO_Assign);
802   ComplexPairTy Val; // ignored
803   return ComplexExprEmitter(*this).EmitBinAssignLValue(E, Val);
804 }
805 
806 LValue CodeGenFunction::
807 EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E) {
808   ComplexPairTy(ComplexExprEmitter::*Op)(const ComplexExprEmitter::BinOpInfo &);
809   switch (E->getOpcode()) {
810   case BO_MulAssign: Op = &ComplexExprEmitter::EmitBinMul; break;
811   case BO_DivAssign: Op = &ComplexExprEmitter::EmitBinDiv; break;
812   case BO_SubAssign: Op = &ComplexExprEmitter::EmitBinSub; break;
813   case BO_AddAssign: Op = &ComplexExprEmitter::EmitBinAdd; break;
814 
815   default:
816     llvm_unreachable("unexpected complex compound assignment");
817     Op = 0;
818   }
819 
820   ComplexPairTy Val; // ignored
821   return ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
822 }
823