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