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 
116   // l-values.
117   ComplexPairTy VisitDeclRefExpr(const Expr *E) { return EmitLoadOfLValue(E); }
118   ComplexPairTy VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
119     return EmitLoadOfLValue(E);
120   }
121   ComplexPairTy VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
122     assert(E->getObjectKind() == OK_Ordinary);
123     return EmitLoadOfLValue(E);
124   }
125   ComplexPairTy VisitObjCMessageExpr(ObjCMessageExpr *E) {
126     return CGF.EmitObjCMessageExpr(E).getComplexVal();
127   }
128   ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
129   ComplexPairTy VisitMemberExpr(const Expr *E) { return EmitLoadOfLValue(E); }
130   ComplexPairTy VisitOpaqueValueExpr(OpaqueValueExpr *E) {
131     if (E->isGLValue())
132       return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E));
133     return CGF.getOpaqueRValueMapping(E).getComplexVal();
134   }
135 
136   // FIXME: CompoundLiteralExpr
137 
138   ComplexPairTy EmitCast(CastExpr::CastKind CK, Expr *Op, QualType DestTy);
139   ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
140     // Unlike for scalars, we don't have to worry about function->ptr demotion
141     // here.
142     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
143   }
144   ComplexPairTy VisitCastExpr(CastExpr *E) {
145     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
146   }
147   ComplexPairTy VisitCallExpr(const CallExpr *E);
148   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
149 
150   // Operators.
151   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
152                                    bool isInc, bool isPre) {
153     LValue LV = CGF.EmitLValue(E->getSubExpr());
154     return CGF.EmitComplexPrePostIncDec(E, LV, isInc, isPre);
155   }
156   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
157     return VisitPrePostIncDec(E, false, false);
158   }
159   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
160     return VisitPrePostIncDec(E, true, false);
161   }
162   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
163     return VisitPrePostIncDec(E, false, true);
164   }
165   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
166     return VisitPrePostIncDec(E, true, true);
167   }
168   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
169   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
170     TestAndClearIgnoreReal();
171     TestAndClearIgnoreImag();
172     return Visit(E->getSubExpr());
173   }
174   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
175   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
176   // LNot,Real,Imag never return complex.
177   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
178     return Visit(E->getSubExpr());
179   }
180   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
181     return Visit(DAE->getExpr());
182   }
183   ComplexPairTy VisitExprWithCleanups(ExprWithCleanups *E) {
184     return CGF.EmitExprWithCleanups(E).getComplexVal();
185   }
186   ComplexPairTy VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
187     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
188     QualType Elem = E->getType()->getAs<ComplexType>()->getElementType();
189     llvm::Constant *Null = llvm::Constant::getNullValue(CGF.ConvertType(Elem));
190     return ComplexPairTy(Null, Null);
191   }
192   ComplexPairTy VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
193     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
194     QualType Elem = E->getType()->getAs<ComplexType>()->getElementType();
195     llvm::Constant *Null =
196                        llvm::Constant::getNullValue(CGF.ConvertType(Elem));
197     return ComplexPairTy(Null, Null);
198   }
199 
200   struct BinOpInfo {
201     ComplexPairTy LHS;
202     ComplexPairTy RHS;
203     QualType Ty;  // Computation Type.
204   };
205 
206   BinOpInfo EmitBinOps(const BinaryOperator *E);
207   LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
208                                   ComplexPairTy (ComplexExprEmitter::*Func)
209                                   (const BinOpInfo &),
210                                   ComplexPairTy &Val);
211   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
212                                    ComplexPairTy (ComplexExprEmitter::*Func)
213                                    (const BinOpInfo &));
214 
215   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
216   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
217   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
218   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
219 
220   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
221     return EmitBinAdd(EmitBinOps(E));
222   }
223   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
224     return EmitBinSub(EmitBinOps(E));
225   }
226   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
227     return EmitBinMul(EmitBinOps(E));
228   }
229   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
230     return EmitBinDiv(EmitBinOps(E));
231   }
232 
233   // Compound assignments.
234   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
235     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
236   }
237   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
238     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
239   }
240   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
241     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
242   }
243   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
244     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
245   }
246 
247   // GCC rejects rem/and/or/xor for integer complex.
248   // Logical and/or always return int, never complex.
249 
250   // No comparisons produce a complex result.
251 
252   LValue EmitBinAssignLValue(const BinaryOperator *E,
253                              ComplexPairTy &Val);
254   ComplexPairTy VisitBinAssign     (const BinaryOperator *E);
255   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
256 
257 
258   ComplexPairTy
259   VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
260   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
261 
262   ComplexPairTy VisitInitListExpr(InitListExpr *E);
263 
264   ComplexPairTy VisitVAArgExpr(VAArgExpr *E);
265 };
266 }  // end anonymous namespace.
267 
268 //===----------------------------------------------------------------------===//
269 //                                Utilities
270 //===----------------------------------------------------------------------===//
271 
272 /// EmitLoadOfComplex - Given an RValue reference for a complex, emit code to
273 /// load the real and imaginary pieces, returning them as Real/Imag.
274 ComplexPairTy ComplexExprEmitter::EmitLoadOfComplex(llvm::Value *SrcPtr,
275                                                     bool isVolatile) {
276   llvm::Value *Real=0, *Imag=0;
277 
278   if (!IgnoreReal || isVolatile) {
279     llvm::Value *RealP = Builder.CreateStructGEP(SrcPtr, 0,
280                                                  SrcPtr->getName() + ".realp");
281     Real = Builder.CreateLoad(RealP, isVolatile, SrcPtr->getName() + ".real");
282   }
283 
284   if (!IgnoreImag || isVolatile) {
285     llvm::Value *ImagP = Builder.CreateStructGEP(SrcPtr, 1,
286                                                  SrcPtr->getName() + ".imagp");
287     Imag = Builder.CreateLoad(ImagP, isVolatile, SrcPtr->getName() + ".imag");
288   }
289   return ComplexPairTy(Real, Imag);
290 }
291 
292 /// EmitStoreOfComplex - Store the specified real/imag parts into the
293 /// specified value pointer.
294 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *Ptr,
295                                             bool isVolatile) {
296   llvm::Value *RealPtr = Builder.CreateStructGEP(Ptr, 0, "real");
297   llvm::Value *ImagPtr = Builder.CreateStructGEP(Ptr, 1, "imag");
298 
299   Builder.CreateStore(Val.first, RealPtr, isVolatile);
300   Builder.CreateStore(Val.second, ImagPtr, isVolatile);
301 }
302 
303 
304 
305 //===----------------------------------------------------------------------===//
306 //                            Visitor Methods
307 //===----------------------------------------------------------------------===//
308 
309 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
310   CGF.ErrorUnsupported(E, "complex expression");
311   const llvm::Type *EltTy =
312     CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
313   llvm::Value *U = llvm::UndefValue::get(EltTy);
314   return ComplexPairTy(U, U);
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     llvm_unreachable("invalid cast kind for complex value");
411 
412   case CK_FloatingRealToComplex:
413   case CK_IntegralRealToComplex: {
414     llvm::Value *Elt = CGF.EmitScalarExpr(Op);
415 
416     // Convert the input element to the element type of the complex.
417     DestTy = DestTy->getAs<ComplexType>()->getElementType();
418     Elt = CGF.EmitScalarConversion(Elt, Op->getType(), DestTy);
419 
420     // Return (realval, 0).
421     return ComplexPairTy(Elt, llvm::Constant::getNullValue(Elt->getType()));
422   }
423 
424   case CK_FloatingComplexCast:
425   case CK_FloatingComplexToIntegralComplex:
426   case CK_IntegralComplexCast:
427   case CK_IntegralComplexToFloatingComplex:
428     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
429   }
430 
431   llvm_unreachable("unknown cast resulting in complex value");
432 }
433 
434 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
435   TestAndClearIgnoreReal();
436   TestAndClearIgnoreImag();
437   ComplexPairTy Op = Visit(E->getSubExpr());
438 
439   llvm::Value *ResR, *ResI;
440   if (Op.first->getType()->isFloatingPointTy()) {
441     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
442     ResI = Builder.CreateFNeg(Op.second, "neg.i");
443   } else {
444     ResR = Builder.CreateNeg(Op.first,  "neg.r");
445     ResI = Builder.CreateNeg(Op.second, "neg.i");
446   }
447   return ComplexPairTy(ResR, ResI);
448 }
449 
450 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
451   TestAndClearIgnoreReal();
452   TestAndClearIgnoreImag();
453   // ~(a+ib) = a + i*-b
454   ComplexPairTy Op = Visit(E->getSubExpr());
455   llvm::Value *ResI;
456   if (Op.second->getType()->isFloatingPointTy())
457     ResI = Builder.CreateFNeg(Op.second, "conj.i");
458   else
459     ResI = Builder.CreateNeg(Op.second, "conj.i");
460 
461   return ComplexPairTy(Op.first, ResI);
462 }
463 
464 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
465   llvm::Value *ResR, *ResI;
466 
467   if (Op.LHS.first->getType()->isFloatingPointTy()) {
468     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
469     ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
470   } else {
471     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
472     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
473   }
474   return ComplexPairTy(ResR, ResI);
475 }
476 
477 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
478   llvm::Value *ResR, *ResI;
479   if (Op.LHS.first->getType()->isFloatingPointTy()) {
480     ResR = Builder.CreateFSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
481     ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
482   } else {
483     ResR = Builder.CreateSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
484     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
485   }
486   return ComplexPairTy(ResR, ResI);
487 }
488 
489 
490 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
491   using llvm::Value;
492   Value *ResR, *ResI;
493 
494   if (Op.LHS.first->getType()->isFloatingPointTy()) {
495     Value *ResRl = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
496     Value *ResRr = Builder.CreateFMul(Op.LHS.second, Op.RHS.second,"mul.rr");
497     ResR  = Builder.CreateFSub(ResRl, ResRr, "mul.r");
498 
499     Value *ResIl = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il");
500     Value *ResIr = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
501     ResI  = Builder.CreateFAdd(ResIl, ResIr, "mul.i");
502   } else {
503     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
504     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
505     ResR  = Builder.CreateSub(ResRl, ResRr, "mul.r");
506 
507     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
508     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
509     ResI  = Builder.CreateAdd(ResIl, ResIr, "mul.i");
510   }
511   return ComplexPairTy(ResR, ResI);
512 }
513 
514 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
515   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
516   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
517 
518 
519   llvm::Value *DSTr, *DSTi;
520   if (Op.LHS.first->getType()->isFloatingPointTy()) {
521     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
522     llvm::Value *Tmp1 = Builder.CreateFMul(LHSr, RHSr, "tmp"); // a*c
523     llvm::Value *Tmp2 = Builder.CreateFMul(LHSi, RHSi, "tmp"); // b*d
524     llvm::Value *Tmp3 = Builder.CreateFAdd(Tmp1, Tmp2, "tmp"); // ac+bd
525 
526     llvm::Value *Tmp4 = Builder.CreateFMul(RHSr, RHSr, "tmp"); // c*c
527     llvm::Value *Tmp5 = Builder.CreateFMul(RHSi, RHSi, "tmp"); // d*d
528     llvm::Value *Tmp6 = Builder.CreateFAdd(Tmp4, Tmp5, "tmp"); // cc+dd
529 
530     llvm::Value *Tmp7 = Builder.CreateFMul(LHSi, RHSr, "tmp"); // b*c
531     llvm::Value *Tmp8 = Builder.CreateFMul(LHSr, RHSi, "tmp"); // a*d
532     llvm::Value *Tmp9 = Builder.CreateFSub(Tmp7, Tmp8, "tmp"); // bc-ad
533 
534     DSTr = Builder.CreateFDiv(Tmp3, Tmp6, "tmp");
535     DSTi = Builder.CreateFDiv(Tmp9, Tmp6, "tmp");
536   } else {
537     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
538     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr, "tmp"); // a*c
539     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi, "tmp"); // b*d
540     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2, "tmp"); // ac+bd
541 
542     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr, "tmp"); // c*c
543     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi, "tmp"); // d*d
544     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5, "tmp"); // cc+dd
545 
546     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr, "tmp"); // b*c
547     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi, "tmp"); // a*d
548     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8, "tmp"); // bc-ad
549 
550     if (Op.Ty->getAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
551       DSTr = Builder.CreateUDiv(Tmp3, Tmp6, "tmp");
552       DSTi = Builder.CreateUDiv(Tmp9, Tmp6, "tmp");
553     } else {
554       DSTr = Builder.CreateSDiv(Tmp3, Tmp6, "tmp");
555       DSTi = Builder.CreateSDiv(Tmp9, Tmp6, "tmp");
556     }
557   }
558 
559   return ComplexPairTy(DSTr, DSTi);
560 }
561 
562 ComplexExprEmitter::BinOpInfo
563 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
564   TestAndClearIgnoreReal();
565   TestAndClearIgnoreImag();
566   BinOpInfo Ops;
567   Ops.LHS = Visit(E->getLHS());
568   Ops.RHS = Visit(E->getRHS());
569   Ops.Ty = E->getType();
570   return Ops;
571 }
572 
573 
574 LValue ComplexExprEmitter::
575 EmitCompoundAssignLValue(const CompoundAssignOperator *E,
576           ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&),
577                          ComplexPairTy &Val) {
578   TestAndClearIgnoreReal();
579   TestAndClearIgnoreImag();
580   QualType LHSTy = E->getLHS()->getType();
581 
582   BinOpInfo OpInfo;
583 
584   // Load the RHS and LHS operands.
585   // __block variables need to have the rhs evaluated first, plus this should
586   // improve codegen a little.
587   OpInfo.Ty = E->getComputationResultType();
588 
589   // The RHS should have been converted to the computation type.
590   assert(OpInfo.Ty->isAnyComplexType());
591   assert(CGF.getContext().hasSameUnqualifiedType(OpInfo.Ty,
592                                                  E->getRHS()->getType()));
593   OpInfo.RHS = Visit(E->getRHS());
594 
595   LValue LHS = CGF.EmitLValue(E->getLHS());
596 
597   // Load from the l-value.
598   ComplexPairTy LHSComplexPair = EmitLoadOfLValue(LHS);
599 
600   OpInfo.LHS = EmitComplexToComplexCast(LHSComplexPair, LHSTy, OpInfo.Ty);
601 
602   // Expand the binary operator.
603   ComplexPairTy Result = (this->*Func)(OpInfo);
604 
605   // Truncate the result back to the LHS type.
606   Result = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
607   Val = Result;
608 
609   // Store the result value into the LHS lvalue.
610   EmitStoreThroughLValue(Result, LHS);
611 
612   return LHS;
613 }
614 
615 // Compound assignments.
616 ComplexPairTy ComplexExprEmitter::
617 EmitCompoundAssign(const CompoundAssignOperator *E,
618                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
619   ComplexPairTy Val;
620   LValue LV = EmitCompoundAssignLValue(E, Func, Val);
621 
622   // The result of an assignment in C is the assigned r-value.
623   if (!CGF.getContext().getLangOptions().CPlusPlus)
624     return Val;
625 
626   // Objective-C property assignment never reloads the value following a store.
627   if (LV.isPropertyRef())
628     return Val;
629 
630   // If the lvalue is non-volatile, return the computed value of the assignment.
631   if (!LV.isVolatileQualified())
632     return Val;
633 
634   return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
635 }
636 
637 LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
638                                                ComplexPairTy &Val) {
639   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
640                                                  E->getRHS()->getType()) &&
641          "Invalid assignment");
642   TestAndClearIgnoreReal();
643   TestAndClearIgnoreImag();
644 
645   // Emit the RHS.  __block variables need the RHS evaluated first.
646   Val = Visit(E->getRHS());
647 
648   // Compute the address to store into.
649   LValue LHS = CGF.EmitLValue(E->getLHS());
650 
651   // Store the result value into the LHS lvalue.
652   EmitStoreThroughLValue(Val, LHS);
653 
654   return LHS;
655 }
656 
657 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
658   ComplexPairTy Val;
659   LValue LV = EmitBinAssignLValue(E, Val);
660 
661   // The result of an assignment in C is the assigned r-value.
662   if (!CGF.getContext().getLangOptions().CPlusPlus)
663     return Val;
664 
665   // Objective-C property assignment never reloads the value following a store.
666   if (LV.isPropertyRef())
667     return Val;
668 
669   // If the lvalue is non-volatile, return the computed value of the assignment.
670   if (!LV.isVolatileQualified())
671     return Val;
672 
673   return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
674 }
675 
676 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
677   CGF.EmitIgnoredExpr(E->getLHS());
678   return Visit(E->getRHS());
679 }
680 
681 ComplexPairTy ComplexExprEmitter::
682 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
683   TestAndClearIgnoreReal();
684   TestAndClearIgnoreImag();
685   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
686   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
687   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
688 
689   // Bind the common expression if necessary.
690   CodeGenFunction::OpaqueValueMapping binding(CGF, E);
691 
692   CodeGenFunction::ConditionalEvaluation eval(CGF);
693   CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
694 
695   eval.begin(CGF);
696   CGF.EmitBlock(LHSBlock);
697   ComplexPairTy LHS = Visit(E->getTrueExpr());
698   LHSBlock = Builder.GetInsertBlock();
699   CGF.EmitBranch(ContBlock);
700   eval.end(CGF);
701 
702   eval.begin(CGF);
703   CGF.EmitBlock(RHSBlock);
704   ComplexPairTy RHS = Visit(E->getFalseExpr());
705   RHSBlock = Builder.GetInsertBlock();
706   CGF.EmitBlock(ContBlock);
707   eval.end(CGF);
708 
709   // Create a PHI node for the real part.
710   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.r");
711   RealPN->addIncoming(LHS.first, LHSBlock);
712   RealPN->addIncoming(RHS.first, RHSBlock);
713 
714   // Create a PHI node for the imaginary part.
715   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.i");
716   ImagPN->addIncoming(LHS.second, LHSBlock);
717   ImagPN->addIncoming(RHS.second, RHSBlock);
718 
719   return ComplexPairTy(RealPN, ImagPN);
720 }
721 
722 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
723   return Visit(E->getChosenSubExpr(CGF.getContext()));
724 }
725 
726 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
727     bool Ignore = TestAndClearIgnoreReal();
728     (void)Ignore;
729     assert (Ignore == false && "init list ignored");
730     Ignore = TestAndClearIgnoreImag();
731     (void)Ignore;
732     assert (Ignore == false && "init list ignored");
733   if (E->getNumInits())
734     return Visit(E->getInit(0));
735 
736   // Empty init list intializes to null
737   QualType Ty = E->getType()->getAs<ComplexType>()->getElementType();
738   const llvm::Type* LTy = CGF.ConvertType(Ty);
739   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
740   return ComplexPairTy(zeroConstant, zeroConstant);
741 }
742 
743 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
744   llvm::Value *ArgValue = CGF.EmitVAListRef(E->getSubExpr());
745   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, E->getType());
746 
747   if (!ArgPtr) {
748     CGF.ErrorUnsupported(E, "complex va_arg expression");
749     const llvm::Type *EltTy =
750       CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
751     llvm::Value *U = llvm::UndefValue::get(EltTy);
752     return ComplexPairTy(U, U);
753   }
754 
755   // FIXME Volatility.
756   return EmitLoadOfComplex(ArgPtr, false);
757 }
758 
759 //===----------------------------------------------------------------------===//
760 //                         Entry Point into this File
761 //===----------------------------------------------------------------------===//
762 
763 /// EmitComplexExpr - Emit the computation of the specified expression of
764 /// complex type, ignoring the result.
765 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
766                                                bool IgnoreImag) {
767   assert(E && E->getType()->isAnyComplexType() &&
768          "Invalid complex expression to emit");
769 
770   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag)
771     .Visit(const_cast<Expr*>(E));
772 }
773 
774 /// EmitComplexExprIntoAddr - Emit the computation of the specified expression
775 /// of complex type, storing into the specified Value*.
776 void CodeGenFunction::EmitComplexExprIntoAddr(const Expr *E,
777                                               llvm::Value *DestAddr,
778                                               bool DestIsVolatile) {
779   assert(E && E->getType()->isAnyComplexType() &&
780          "Invalid complex expression to emit");
781   ComplexExprEmitter Emitter(*this);
782   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
783   Emitter.EmitStoreOfComplex(Val, DestAddr, DestIsVolatile);
784 }
785 
786 /// StoreComplexToAddr - Store a complex number into the specified address.
787 void CodeGenFunction::StoreComplexToAddr(ComplexPairTy V,
788                                          llvm::Value *DestAddr,
789                                          bool DestIsVolatile) {
790   ComplexExprEmitter(*this).EmitStoreOfComplex(V, DestAddr, DestIsVolatile);
791 }
792 
793 /// LoadComplexFromAddr - Load a complex number from the specified address.
794 ComplexPairTy CodeGenFunction::LoadComplexFromAddr(llvm::Value *SrcAddr,
795                                                    bool SrcIsVolatile) {
796   return ComplexExprEmitter(*this).EmitLoadOfComplex(SrcAddr, SrcIsVolatile);
797 }
798 
799 LValue CodeGenFunction::EmitComplexAssignmentLValue(const BinaryOperator *E) {
800   assert(E->getOpcode() == BO_Assign);
801   ComplexPairTy Val; // ignored
802   return ComplexExprEmitter(*this).EmitBinAssignLValue(E, Val);
803 }
804 
805 LValue CodeGenFunction::
806 EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E) {
807   ComplexPairTy(ComplexExprEmitter::*Op)(const ComplexExprEmitter::BinOpInfo &);
808   switch (E->getOpcode()) {
809   case BO_MulAssign: Op = &ComplexExprEmitter::EmitBinMul; break;
810   case BO_DivAssign: Op = &ComplexExprEmitter::EmitBinDiv; break;
811   case BO_SubAssign: Op = &ComplexExprEmitter::EmitBinSub; break;
812   case BO_AddAssign: Op = &ComplexExprEmitter::EmitBinAdd; break;
813 
814   default:
815     llvm_unreachable("unexpected complex compound assignment");
816     Op = 0;
817   }
818 
819   ComplexPairTy Val; // ignored
820   return ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
821 }
822