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     CGF.enterFullExpression(E);
183     CodeGenFunction::RunCleanupsScope Scope(CGF);
184     return Visit(E->getSubExpr());
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 VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
265     return EmitLoadOfLValue(E);
266   }
267 
268   ComplexPairTy VisitVAArgExpr(VAArgExpr *E);
269 
270   ComplexPairTy VisitAtomicExpr(AtomicExpr *E) {
271     return CGF.EmitAtomicExpr(E).getComplexVal();
272   }
273 };
274 }  // end anonymous namespace.
275 
276 //===----------------------------------------------------------------------===//
277 //                                Utilities
278 //===----------------------------------------------------------------------===//
279 
280 /// EmitLoadOfComplex - Given an RValue reference for a complex, emit code to
281 /// load the real and imaginary pieces, returning them as Real/Imag.
282 ComplexPairTy ComplexExprEmitter::EmitLoadOfComplex(llvm::Value *SrcPtr,
283                                                     bool isVolatile) {
284   llvm::Value *Real=0, *Imag=0;
285 
286   if (!IgnoreReal || isVolatile) {
287     llvm::Value *RealP = Builder.CreateStructGEP(SrcPtr, 0,
288                                                  SrcPtr->getName() + ".realp");
289     Real = Builder.CreateLoad(RealP, isVolatile, SrcPtr->getName() + ".real");
290   }
291 
292   if (!IgnoreImag || isVolatile) {
293     llvm::Value *ImagP = Builder.CreateStructGEP(SrcPtr, 1,
294                                                  SrcPtr->getName() + ".imagp");
295     Imag = Builder.CreateLoad(ImagP, isVolatile, SrcPtr->getName() + ".imag");
296   }
297   return ComplexPairTy(Real, Imag);
298 }
299 
300 /// EmitStoreOfComplex - Store the specified real/imag parts into the
301 /// specified value pointer.
302 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *Ptr,
303                                             bool isVolatile) {
304   llvm::Value *RealPtr = Builder.CreateStructGEP(Ptr, 0, "real");
305   llvm::Value *ImagPtr = Builder.CreateStructGEP(Ptr, 1, "imag");
306 
307   Builder.CreateStore(Val.first, RealPtr, isVolatile);
308   Builder.CreateStore(Val.second, ImagPtr, isVolatile);
309 }
310 
311 
312 
313 //===----------------------------------------------------------------------===//
314 //                            Visitor Methods
315 //===----------------------------------------------------------------------===//
316 
317 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
318   CGF.ErrorUnsupported(E, "complex expression");
319   llvm::Type *EltTy =
320   CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
321   llvm::Value *U = llvm::UndefValue::get(EltTy);
322   return ComplexPairTy(U, U);
323 }
324 
325 ComplexPairTy ComplexExprEmitter::
326 VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
327   llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
328   return ComplexPairTy(llvm::Constant::getNullValue(Imag->getType()), Imag);
329 }
330 
331 
332 ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
333   if (E->getCallReturnType()->isReferenceType())
334     return EmitLoadOfLValue(E);
335 
336   return CGF.EmitCallExpr(E).getComplexVal();
337 }
338 
339 ComplexPairTy ComplexExprEmitter::VisitStmtExpr(const StmtExpr *E) {
340   CodeGenFunction::StmtExprEvaluation eval(CGF);
341   return CGF.EmitCompoundStmt(*E->getSubStmt(), true).getComplexVal();
342 }
343 
344 /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
345 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
346                                                            QualType SrcType,
347                                                            QualType DestType) {
348   // Get the src/dest element type.
349   SrcType = SrcType->getAs<ComplexType>()->getElementType();
350   DestType = DestType->getAs<ComplexType>()->getElementType();
351 
352   // C99 6.3.1.6: When a value of complex type is converted to another
353   // complex type, both the real and imaginary parts follow the conversion
354   // rules for the corresponding real types.
355   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType);
356   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType);
357   return Val;
358 }
359 
360 ComplexPairTy ComplexExprEmitter::EmitCast(CastExpr::CastKind CK, Expr *Op,
361                                            QualType DestTy) {
362   switch (CK) {
363   case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!");
364 
365   // Atomic to non-atomic casts may be more than a no-op for some platforms and
366   // for some types.
367   case CK_AtomicToNonAtomic:
368   case CK_NonAtomicToAtomic:
369   case CK_NoOp:
370   case CK_LValueToRValue:
371   case CK_UserDefinedConversion:
372     return Visit(Op);
373 
374   case CK_LValueBitCast: {
375     llvm::Value *V = CGF.EmitLValue(Op).getAddress();
376     V = Builder.CreateBitCast(V,
377                     CGF.ConvertType(CGF.getContext().getPointerType(DestTy)));
378     // FIXME: Are the qualifiers correct here?
379     return EmitLoadOfComplex(V, DestTy.isVolatileQualified());
380   }
381 
382   case CK_BitCast:
383   case CK_BaseToDerived:
384   case CK_DerivedToBase:
385   case CK_UncheckedDerivedToBase:
386   case CK_Dynamic:
387   case CK_ToUnion:
388   case CK_ArrayToPointerDecay:
389   case CK_FunctionToPointerDecay:
390   case CK_NullToPointer:
391   case CK_NullToMemberPointer:
392   case CK_BaseToDerivedMemberPointer:
393   case CK_DerivedToBaseMemberPointer:
394   case CK_MemberPointerToBoolean:
395   case CK_ReinterpretMemberPointer:
396   case CK_ConstructorConversion:
397   case CK_IntegralToPointer:
398   case CK_PointerToIntegral:
399   case CK_PointerToBoolean:
400   case CK_ToVoid:
401   case CK_VectorSplat:
402   case CK_IntegralCast:
403   case CK_IntegralToBoolean:
404   case CK_IntegralToFloating:
405   case CK_FloatingToIntegral:
406   case CK_FloatingToBoolean:
407   case CK_FloatingCast:
408   case CK_CPointerToObjCPointerCast:
409   case CK_BlockPointerToObjCPointerCast:
410   case CK_AnyPointerToBlockPointerCast:
411   case CK_ObjCObjectLValueCast:
412   case CK_FloatingComplexToReal:
413   case CK_FloatingComplexToBoolean:
414   case CK_IntegralComplexToReal:
415   case CK_IntegralComplexToBoolean:
416   case CK_ARCProduceObject:
417   case CK_ARCConsumeObject:
418   case CK_ARCReclaimReturnedObject:
419   case CK_ARCExtendBlockObject:
420   case CK_CopyAndAutoreleaseBlockObject:
421     llvm_unreachable("invalid cast kind for complex value");
422 
423   case CK_FloatingRealToComplex:
424   case CK_IntegralRealToComplex: {
425     llvm::Value *Elt = CGF.EmitScalarExpr(Op);
426 
427     // Convert the input element to the element type of the complex.
428     DestTy = DestTy->getAs<ComplexType>()->getElementType();
429     Elt = CGF.EmitScalarConversion(Elt, Op->getType(), DestTy);
430 
431     // Return (realval, 0).
432     return ComplexPairTy(Elt, llvm::Constant::getNullValue(Elt->getType()));
433   }
434 
435   case CK_FloatingComplexCast:
436   case CK_FloatingComplexToIntegralComplex:
437   case CK_IntegralComplexCast:
438   case CK_IntegralComplexToFloatingComplex:
439     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
440   }
441 
442   llvm_unreachable("unknown cast resulting in complex value");
443 }
444 
445 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
446   TestAndClearIgnoreReal();
447   TestAndClearIgnoreImag();
448   ComplexPairTy Op = Visit(E->getSubExpr());
449 
450   llvm::Value *ResR, *ResI;
451   if (Op.first->getType()->isFloatingPointTy()) {
452     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
453     ResI = Builder.CreateFNeg(Op.second, "neg.i");
454   } else {
455     ResR = Builder.CreateNeg(Op.first,  "neg.r");
456     ResI = Builder.CreateNeg(Op.second, "neg.i");
457   }
458   return ComplexPairTy(ResR, ResI);
459 }
460 
461 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
462   TestAndClearIgnoreReal();
463   TestAndClearIgnoreImag();
464   // ~(a+ib) = a + i*-b
465   ComplexPairTy Op = Visit(E->getSubExpr());
466   llvm::Value *ResI;
467   if (Op.second->getType()->isFloatingPointTy())
468     ResI = Builder.CreateFNeg(Op.second, "conj.i");
469   else
470     ResI = Builder.CreateNeg(Op.second, "conj.i");
471 
472   return ComplexPairTy(Op.first, ResI);
473 }
474 
475 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
476   llvm::Value *ResR, *ResI;
477 
478   if (Op.LHS.first->getType()->isFloatingPointTy()) {
479     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
480     ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
481   } else {
482     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
483     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
484   }
485   return ComplexPairTy(ResR, ResI);
486 }
487 
488 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
489   llvm::Value *ResR, *ResI;
490   if (Op.LHS.first->getType()->isFloatingPointTy()) {
491     ResR = Builder.CreateFSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
492     ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
493   } else {
494     ResR = Builder.CreateSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
495     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
496   }
497   return ComplexPairTy(ResR, ResI);
498 }
499 
500 
501 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
502   using llvm::Value;
503   Value *ResR, *ResI;
504 
505   if (Op.LHS.first->getType()->isFloatingPointTy()) {
506     Value *ResRl = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
507     Value *ResRr = Builder.CreateFMul(Op.LHS.second, Op.RHS.second,"mul.rr");
508     ResR  = Builder.CreateFSub(ResRl, ResRr, "mul.r");
509 
510     Value *ResIl = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il");
511     Value *ResIr = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
512     ResI  = Builder.CreateFAdd(ResIl, ResIr, "mul.i");
513   } else {
514     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
515     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
516     ResR  = Builder.CreateSub(ResRl, ResRr, "mul.r");
517 
518     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
519     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
520     ResI  = Builder.CreateAdd(ResIl, ResIr, "mul.i");
521   }
522   return ComplexPairTy(ResR, ResI);
523 }
524 
525 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
526   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
527   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
528 
529 
530   llvm::Value *DSTr, *DSTi;
531   if (Op.LHS.first->getType()->isFloatingPointTy()) {
532     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
533     llvm::Value *Tmp1 = Builder.CreateFMul(LHSr, RHSr); // a*c
534     llvm::Value *Tmp2 = Builder.CreateFMul(LHSi, RHSi); // b*d
535     llvm::Value *Tmp3 = Builder.CreateFAdd(Tmp1, Tmp2); // ac+bd
536 
537     llvm::Value *Tmp4 = Builder.CreateFMul(RHSr, RHSr); // c*c
538     llvm::Value *Tmp5 = Builder.CreateFMul(RHSi, RHSi); // d*d
539     llvm::Value *Tmp6 = Builder.CreateFAdd(Tmp4, Tmp5); // cc+dd
540 
541     llvm::Value *Tmp7 = Builder.CreateFMul(LHSi, RHSr); // b*c
542     llvm::Value *Tmp8 = Builder.CreateFMul(LHSr, RHSi); // a*d
543     llvm::Value *Tmp9 = Builder.CreateFSub(Tmp7, Tmp8); // bc-ad
544 
545     DSTr = Builder.CreateFDiv(Tmp3, Tmp6);
546     DSTi = Builder.CreateFDiv(Tmp9, Tmp6);
547   } else {
548     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
549     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr); // a*c
550     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi); // b*d
551     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2); // ac+bd
552 
553     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr); // c*c
554     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi); // d*d
555     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5); // cc+dd
556 
557     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr); // b*c
558     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi); // a*d
559     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8); // bc-ad
560 
561     if (Op.Ty->getAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
562       DSTr = Builder.CreateUDiv(Tmp3, Tmp6);
563       DSTi = Builder.CreateUDiv(Tmp9, Tmp6);
564     } else {
565       DSTr = Builder.CreateSDiv(Tmp3, Tmp6);
566       DSTi = Builder.CreateSDiv(Tmp9, Tmp6);
567     }
568   }
569 
570   return ComplexPairTy(DSTr, DSTi);
571 }
572 
573 ComplexExprEmitter::BinOpInfo
574 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
575   TestAndClearIgnoreReal();
576   TestAndClearIgnoreImag();
577   BinOpInfo Ops;
578   Ops.LHS = Visit(E->getLHS());
579   Ops.RHS = Visit(E->getRHS());
580   Ops.Ty = E->getType();
581   return Ops;
582 }
583 
584 
585 LValue ComplexExprEmitter::
586 EmitCompoundAssignLValue(const CompoundAssignOperator *E,
587           ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&),
588                          ComplexPairTy &Val) {
589   TestAndClearIgnoreReal();
590   TestAndClearIgnoreImag();
591   QualType LHSTy = E->getLHS()->getType();
592 
593   BinOpInfo OpInfo;
594 
595   // Load the RHS and LHS operands.
596   // __block variables need to have the rhs evaluated first, plus this should
597   // improve codegen a little.
598   OpInfo.Ty = E->getComputationResultType();
599 
600   // The RHS should have been converted to the computation type.
601   assert(OpInfo.Ty->isAnyComplexType());
602   assert(CGF.getContext().hasSameUnqualifiedType(OpInfo.Ty,
603                                                  E->getRHS()->getType()));
604   OpInfo.RHS = Visit(E->getRHS());
605 
606   LValue LHS = CGF.EmitLValue(E->getLHS());
607 
608   // Load from the l-value.
609   ComplexPairTy LHSComplexPair = EmitLoadOfLValue(LHS);
610 
611   OpInfo.LHS = EmitComplexToComplexCast(LHSComplexPair, LHSTy, OpInfo.Ty);
612 
613   // Expand the binary operator.
614   ComplexPairTy Result = (this->*Func)(OpInfo);
615 
616   // Truncate the result back to the LHS type.
617   Result = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
618   Val = Result;
619 
620   // Store the result value into the LHS lvalue.
621   EmitStoreThroughLValue(Result, LHS);
622 
623   return LHS;
624 }
625 
626 // Compound assignments.
627 ComplexPairTy ComplexExprEmitter::
628 EmitCompoundAssign(const CompoundAssignOperator *E,
629                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
630   ComplexPairTy Val;
631   LValue LV = EmitCompoundAssignLValue(E, Func, Val);
632 
633   // The result of an assignment in C is the assigned r-value.
634   if (!CGF.getContext().getLangOptions().CPlusPlus)
635     return Val;
636 
637   // If the lvalue is non-volatile, return the computed value of the assignment.
638   if (!LV.isVolatileQualified())
639     return Val;
640 
641   return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
642 }
643 
644 LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
645                                                ComplexPairTy &Val) {
646   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
647                                                  E->getRHS()->getType()) &&
648          "Invalid assignment");
649   TestAndClearIgnoreReal();
650   TestAndClearIgnoreImag();
651 
652   // Emit the RHS.  __block variables need the RHS evaluated first.
653   Val = Visit(E->getRHS());
654 
655   // Compute the address to store into.
656   LValue LHS = CGF.EmitLValue(E->getLHS());
657 
658   // Store the result value into the LHS lvalue.
659   EmitStoreThroughLValue(Val, LHS);
660 
661   return LHS;
662 }
663 
664 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
665   ComplexPairTy Val;
666   LValue LV = EmitBinAssignLValue(E, Val);
667 
668   // The result of an assignment in C is the assigned r-value.
669   if (!CGF.getContext().getLangOptions().CPlusPlus)
670     return Val;
671 
672   // If the lvalue is non-volatile, return the computed value of the assignment.
673   if (!LV.isVolatileQualified())
674     return Val;
675 
676   return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
677 }
678 
679 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
680   CGF.EmitIgnoredExpr(E->getLHS());
681   return Visit(E->getRHS());
682 }
683 
684 ComplexPairTy ComplexExprEmitter::
685 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
686   TestAndClearIgnoreReal();
687   TestAndClearIgnoreImag();
688   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
689   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
690   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
691 
692   // Bind the common expression if necessary.
693   CodeGenFunction::OpaqueValueMapping binding(CGF, E);
694 
695   CodeGenFunction::ConditionalEvaluation eval(CGF);
696   CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
697 
698   eval.begin(CGF);
699   CGF.EmitBlock(LHSBlock);
700   ComplexPairTy LHS = Visit(E->getTrueExpr());
701   LHSBlock = Builder.GetInsertBlock();
702   CGF.EmitBranch(ContBlock);
703   eval.end(CGF);
704 
705   eval.begin(CGF);
706   CGF.EmitBlock(RHSBlock);
707   ComplexPairTy RHS = Visit(E->getFalseExpr());
708   RHSBlock = Builder.GetInsertBlock();
709   CGF.EmitBlock(ContBlock);
710   eval.end(CGF);
711 
712   // Create a PHI node for the real part.
713   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.r");
714   RealPN->addIncoming(LHS.first, LHSBlock);
715   RealPN->addIncoming(RHS.first, RHSBlock);
716 
717   // Create a PHI node for the imaginary part.
718   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.i");
719   ImagPN->addIncoming(LHS.second, LHSBlock);
720   ImagPN->addIncoming(RHS.second, RHSBlock);
721 
722   return ComplexPairTy(RealPN, ImagPN);
723 }
724 
725 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
726   return Visit(E->getChosenSubExpr(CGF.getContext()));
727 }
728 
729 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
730     bool Ignore = TestAndClearIgnoreReal();
731     (void)Ignore;
732     assert (Ignore == false && "init list ignored");
733     Ignore = TestAndClearIgnoreImag();
734     (void)Ignore;
735     assert (Ignore == false && "init list ignored");
736 
737   if (E->getNumInits() == 2) {
738     llvm::Value *Real = CGF.EmitScalarExpr(E->getInit(0));
739     llvm::Value *Imag = CGF.EmitScalarExpr(E->getInit(1));
740     return ComplexPairTy(Real, Imag);
741   } else if (E->getNumInits() == 1) {
742     return Visit(E->getInit(0));
743   }
744 
745   // Empty init list intializes to null
746   assert(E->getNumInits() == 0 && "Unexpected number of inits");
747   QualType Ty = E->getType()->getAs<ComplexType>()->getElementType();
748   llvm::Type* LTy = CGF.ConvertType(Ty);
749   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
750   return ComplexPairTy(zeroConstant, zeroConstant);
751 }
752 
753 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
754   llvm::Value *ArgValue = CGF.EmitVAListRef(E->getSubExpr());
755   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, E->getType());
756 
757   if (!ArgPtr) {
758     CGF.ErrorUnsupported(E, "complex va_arg expression");
759     llvm::Type *EltTy =
760       CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
761     llvm::Value *U = llvm::UndefValue::get(EltTy);
762     return ComplexPairTy(U, U);
763   }
764 
765   // FIXME Volatility.
766   return EmitLoadOfComplex(ArgPtr, false);
767 }
768 
769 //===----------------------------------------------------------------------===//
770 //                         Entry Point into this File
771 //===----------------------------------------------------------------------===//
772 
773 /// EmitComplexExpr - Emit the computation of the specified expression of
774 /// complex type, ignoring the result.
775 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
776                                                bool IgnoreImag) {
777   assert(E && E->getType()->isAnyComplexType() &&
778          "Invalid complex expression to emit");
779 
780   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag)
781     .Visit(const_cast<Expr*>(E));
782 }
783 
784 /// EmitComplexExprIntoAddr - Emit the computation of the specified expression
785 /// of complex type, storing into the specified Value*.
786 void CodeGenFunction::EmitComplexExprIntoAddr(const Expr *E,
787                                               llvm::Value *DestAddr,
788                                               bool DestIsVolatile) {
789   assert(E && E->getType()->isAnyComplexType() &&
790          "Invalid complex expression to emit");
791   ComplexExprEmitter Emitter(*this);
792   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
793   Emitter.EmitStoreOfComplex(Val, DestAddr, DestIsVolatile);
794 }
795 
796 /// StoreComplexToAddr - Store a complex number into the specified address.
797 void CodeGenFunction::StoreComplexToAddr(ComplexPairTy V,
798                                          llvm::Value *DestAddr,
799                                          bool DestIsVolatile) {
800   ComplexExprEmitter(*this).EmitStoreOfComplex(V, DestAddr, DestIsVolatile);
801 }
802 
803 /// LoadComplexFromAddr - Load a complex number from the specified address.
804 ComplexPairTy CodeGenFunction::LoadComplexFromAddr(llvm::Value *SrcAddr,
805                                                    bool SrcIsVolatile) {
806   return ComplexExprEmitter(*this).EmitLoadOfComplex(SrcAddr, SrcIsVolatile);
807 }
808 
809 LValue CodeGenFunction::EmitComplexAssignmentLValue(const BinaryOperator *E) {
810   assert(E->getOpcode() == BO_Assign);
811   ComplexPairTy Val; // ignored
812   return ComplexExprEmitter(*this).EmitBinAssignLValue(E, Val);
813 }
814 
815 LValue CodeGenFunction::
816 EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E) {
817   ComplexPairTy(ComplexExprEmitter::*Op)(const ComplexExprEmitter::BinOpInfo &);
818   switch (E->getOpcode()) {
819   case BO_MulAssign: Op = &ComplexExprEmitter::EmitBinMul; break;
820   case BO_DivAssign: Op = &ComplexExprEmitter::EmitBinDiv; break;
821   case BO_SubAssign: Op = &ComplexExprEmitter::EmitBinSub; break;
822   case BO_AddAssign: Op = &ComplexExprEmitter::EmitBinAdd; break;
823 
824   default:
825     llvm_unreachable("unexpected complex compound assignment");
826   }
827 
828   ComplexPairTy Val; // ignored
829   return ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
830 }
831