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   // True if we should ignore the value of a=b
39   bool IgnoreRealAssign;
40   bool IgnoreImagAssign;
41 public:
42   ComplexExprEmitter(CodeGenFunction &cgf, bool ir=false, bool ii=false,
43                      bool irn=false, bool iin=false)
44     : CGF(cgf), Builder(CGF.Builder), IgnoreReal(ir), IgnoreImag(ii),
45     IgnoreRealAssign(irn), IgnoreImagAssign(iin) {
46   }
47 
48 
49   //===--------------------------------------------------------------------===//
50   //                               Utilities
51   //===--------------------------------------------------------------------===//
52 
53   bool TestAndClearIgnoreReal() {
54     bool I = IgnoreReal;
55     IgnoreReal = false;
56     return I;
57   }
58   bool TestAndClearIgnoreImag() {
59     bool I = IgnoreImag;
60     IgnoreImag = false;
61     return I;
62   }
63   bool TestAndClearIgnoreRealAssign() {
64     bool I = IgnoreRealAssign;
65     IgnoreRealAssign = false;
66     return I;
67   }
68   bool TestAndClearIgnoreImagAssign() {
69     bool I = IgnoreImagAssign;
70     IgnoreImagAssign = false;
71     return I;
72   }
73 
74   /// EmitLoadOfLValue - Given an expression with complex type that represents a
75   /// value l-value, this method emits the address of the l-value, then loads
76   /// and returns the result.
77   ComplexPairTy EmitLoadOfLValue(const Expr *E) {
78     LValue LV = CGF.EmitLValue(E);
79     if (LV.isSimple())
80       return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
81 
82     if (LV.isPropertyRef())
83       return CGF.EmitObjCPropertyGet(LV.getPropertyRefExpr()).getComplexVal();
84 
85     assert(LV.isKVCRef() && "Unknown LValue type!");
86     return CGF.EmitObjCPropertyGet(LV.getKVCRefExpr()).getComplexVal();
87   }
88 
89   /// EmitLoadOfComplex - Given a pointer to a complex value, emit code to load
90   /// the real and imaginary pieces.
91   ComplexPairTy EmitLoadOfComplex(llvm::Value *SrcPtr, bool isVolatile);
92 
93   /// EmitStoreOfComplex - Store the specified real/imag parts into the
94   /// specified value pointer.
95   void EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *ResPtr, bool isVol);
96 
97   /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
98   ComplexPairTy EmitComplexToComplexCast(ComplexPairTy Val, QualType SrcType,
99                                          QualType DestType);
100 
101   //===--------------------------------------------------------------------===//
102   //                            Visitor Methods
103   //===--------------------------------------------------------------------===//
104 
105   ComplexPairTy Visit(Expr *E) {
106     llvm::DenseMap<const Expr *, ComplexPairTy>::iterator I =
107       CGF.ConditionalSaveComplexExprs.find(E);
108     if (I != CGF.ConditionalSaveComplexExprs.end())
109       return I->second;
110 
111       return StmtVisitor<ComplexExprEmitter, ComplexPairTy>::Visit(E);
112   }
113 
114   ComplexPairTy VisitStmt(Stmt *S) {
115     S->dump(CGF.getContext().getSourceManager());
116     assert(0 && "Stmt can't have complex result type!");
117     return ComplexPairTy();
118   }
119   ComplexPairTy VisitExpr(Expr *S);
120   ComplexPairTy VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr());}
121   ComplexPairTy VisitImaginaryLiteral(const ImaginaryLiteral *IL);
122 
123   // l-values.
124   ComplexPairTy VisitDeclRefExpr(const Expr *E) { return EmitLoadOfLValue(E); }
125   ComplexPairTy VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
126     return EmitLoadOfLValue(E);
127   }
128   ComplexPairTy VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
129     return EmitLoadOfLValue(E);
130   }
131   ComplexPairTy VisitObjCImplicitSetterGetterRefExpr(
132                                ObjCImplicitSetterGetterRefExpr *E) {
133     return EmitLoadOfLValue(E);
134   }
135   ComplexPairTy VisitObjCMessageExpr(ObjCMessageExpr *E) {
136     return CGF.EmitObjCMessageExpr(E).getComplexVal();
137   }
138   ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
139   ComplexPairTy VisitMemberExpr(const Expr *E) { return EmitLoadOfLValue(E); }
140 
141   // FIXME: CompoundLiteralExpr
142 
143   ComplexPairTy EmitCast(CastExpr::CastKind CK, Expr *Op, QualType DestTy);
144   ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
145     // Unlike for scalars, we don't have to worry about function->ptr demotion
146     // here.
147     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
148   }
149   ComplexPairTy VisitCastExpr(CastExpr *E) {
150     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
151   }
152   ComplexPairTy VisitCallExpr(const CallExpr *E);
153   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
154 
155   // Operators.
156   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
157                                    bool isInc, bool isPre) {
158     LValue LV = CGF.EmitLValue(E->getSubExpr());
159     return CGF.EmitComplexPrePostIncDec(E, LV, isInc, isPre);
160   }
161   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
162     return VisitPrePostIncDec(E, false, false);
163   }
164   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
165     return VisitPrePostIncDec(E, true, false);
166   }
167   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
168     return VisitPrePostIncDec(E, false, true);
169   }
170   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
171     return VisitPrePostIncDec(E, true, true);
172   }
173   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
174   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
175     TestAndClearIgnoreReal();
176     TestAndClearIgnoreImag();
177     TestAndClearIgnoreRealAssign();
178     TestAndClearIgnoreImagAssign();
179     return Visit(E->getSubExpr());
180   }
181   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
182   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
183   // LNot,Real,Imag never return complex.
184   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
185     return Visit(E->getSubExpr());
186   }
187   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
188     return Visit(DAE->getExpr());
189   }
190   ComplexPairTy VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) {
191     return CGF.EmitCXXExprWithTemporaries(E).getComplexVal();
192   }
193   ComplexPairTy VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
194     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
195     QualType Elem = E->getType()->getAs<ComplexType>()->getElementType();
196     llvm::Constant *Null = llvm::Constant::getNullValue(CGF.ConvertType(Elem));
197     return ComplexPairTy(Null, Null);
198   }
199   ComplexPairTy VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
200     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
201     QualType Elem = E->getType()->getAs<ComplexType>()->getElementType();
202     llvm::Constant *Null =
203                        llvm::Constant::getNullValue(CGF.ConvertType(Elem));
204     return ComplexPairTy(Null, Null);
205   }
206 
207   struct BinOpInfo {
208     ComplexPairTy LHS;
209     ComplexPairTy RHS;
210     QualType Ty;  // Computation Type.
211   };
212 
213   BinOpInfo EmitBinOps(const BinaryOperator *E);
214   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
215                                    ComplexPairTy (ComplexExprEmitter::*Func)
216                                    (const BinOpInfo &));
217 
218   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
219   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
220   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
221   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
222 
223   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
224     return EmitBinMul(EmitBinOps(E));
225   }
226   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
227     return EmitBinAdd(EmitBinOps(E));
228   }
229   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
230     return EmitBinSub(EmitBinOps(E));
231   }
232   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
233     return EmitBinDiv(EmitBinOps(E));
234   }
235 
236   // Compound assignments.
237   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
238     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
239   }
240   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
241     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
242   }
243   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
244     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
245   }
246   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
247     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
248   }
249 
250   // GCC rejects rem/and/or/xor for integer complex.
251   // Logical and/or always return int, never complex.
252 
253   // No comparisons produce a complex result.
254   ComplexPairTy VisitBinAssign     (const BinaryOperator *E);
255   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
256 
257 
258   ComplexPairTy VisitConditionalOperator(const ConditionalOperator *CO);
259   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
260 
261   ComplexPairTy VisitInitListExpr(InitListExpr *E);
262 
263   ComplexPairTy VisitVAArgExpr(VAArgExpr *E);
264 };
265 }  // end anonymous namespace.
266 
267 //===----------------------------------------------------------------------===//
268 //                                Utilities
269 //===----------------------------------------------------------------------===//
270 
271 /// EmitLoadOfComplex - Given an RValue reference for a complex, emit code to
272 /// load the real and imaginary pieces, returning them as Real/Imag.
273 ComplexPairTy ComplexExprEmitter::EmitLoadOfComplex(llvm::Value *SrcPtr,
274                                                     bool isVolatile) {
275   llvm::Value *Real=0, *Imag=0;
276 
277   if (!IgnoreReal) {
278     llvm::Value *RealP = Builder.CreateStructGEP(SrcPtr, 0,
279                                                  SrcPtr->getName() + ".realp");
280     Real = Builder.CreateLoad(RealP, isVolatile, SrcPtr->getName() + ".real");
281   }
282 
283   if (!IgnoreImag) {
284     llvm::Value *ImagP = Builder.CreateStructGEP(SrcPtr, 1,
285                                                  SrcPtr->getName() + ".imagp");
286     Imag = Builder.CreateLoad(ImagP, isVolatile, SrcPtr->getName() + ".imag");
287   }
288   return ComplexPairTy(Real, Imag);
289 }
290 
291 /// EmitStoreOfComplex - Store the specified real/imag parts into the
292 /// specified value pointer.
293 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *Ptr,
294                                             bool isVolatile) {
295   llvm::Value *RealPtr = Builder.CreateStructGEP(Ptr, 0, "real");
296   llvm::Value *ImagPtr = Builder.CreateStructGEP(Ptr, 1, "imag");
297 
298   Builder.CreateStore(Val.first, RealPtr, isVolatile);
299   Builder.CreateStore(Val.second, ImagPtr, isVolatile);
300 }
301 
302 
303 
304 //===----------------------------------------------------------------------===//
305 //                            Visitor Methods
306 //===----------------------------------------------------------------------===//
307 
308 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
309   CGF.ErrorUnsupported(E, "complex expression");
310   const llvm::Type *EltTy =
311     CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
312   llvm::Value *U = llvm::UndefValue::get(EltTy);
313   return ComplexPairTy(U, U);
314 }
315 
316 ComplexPairTy ComplexExprEmitter::
317 VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
318   llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
319   return
320         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   return CGF.EmitCompoundStmt(*E->getSubStmt(), true).getComplexVal();
333 }
334 
335 /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
336 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
337                                                            QualType SrcType,
338                                                            QualType DestType) {
339   // Get the src/dest element type.
340   SrcType = SrcType->getAs<ComplexType>()->getElementType();
341   DestType = DestType->getAs<ComplexType>()->getElementType();
342 
343   // C99 6.3.1.6: When a value of complex type is converted to another
344   // complex type, both the real and imaginary parts follow the conversion
345   // rules for the corresponding real types.
346   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType);
347   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType);
348   return Val;
349 }
350 
351 ComplexPairTy ComplexExprEmitter::EmitCast(CastExpr::CastKind CK, Expr *Op,
352                                            QualType DestTy) {
353   // FIXME: this should be based off of the CastKind.
354 
355   // Two cases here: cast from (complex to complex) and (scalar to complex).
356   if (Op->getType()->isAnyComplexType())
357     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
358 
359   // FIXME: We should be looking at all of the cast kinds here, not
360   // cherry-picking the ones we have test cases for.
361   if (CK == CK_LValueBitCast) {
362     llvm::Value *V = CGF.EmitLValue(Op).getAddress();
363     V = Builder.CreateBitCast(V,
364                       CGF.ConvertType(CGF.getContext().getPointerType(DestTy)));
365     // FIXME: Are the qualifiers correct here?
366     return EmitLoadOfComplex(V, DestTy.isVolatileQualified());
367   }
368 
369   // C99 6.3.1.7: When a value of real type is converted to a complex type, the
370   // real part of the complex result value is determined by the rules of
371   // conversion to the corresponding real type and the imaginary part of the
372   // complex result value is a positive zero or an unsigned zero.
373   llvm::Value *Elt = CGF.EmitScalarExpr(Op);
374 
375   // Convert the input element to the element type of the complex.
376   DestTy = DestTy->getAs<ComplexType>()->getElementType();
377   Elt = CGF.EmitScalarConversion(Elt, Op->getType(), DestTy);
378 
379   // Return (realval, 0).
380   return ComplexPairTy(Elt, llvm::Constant::getNullValue(Elt->getType()));
381 }
382 
383 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
384   TestAndClearIgnoreReal();
385   TestAndClearIgnoreImag();
386   TestAndClearIgnoreRealAssign();
387   TestAndClearIgnoreImagAssign();
388   ComplexPairTy Op = Visit(E->getSubExpr());
389 
390   llvm::Value *ResR, *ResI;
391   if (Op.first->getType()->isFloatingPointTy()) {
392     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
393     ResI = Builder.CreateFNeg(Op.second, "neg.i");
394   } else {
395     ResR = Builder.CreateNeg(Op.first,  "neg.r");
396     ResI = Builder.CreateNeg(Op.second, "neg.i");
397   }
398   return ComplexPairTy(ResR, ResI);
399 }
400 
401 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
402   TestAndClearIgnoreReal();
403   TestAndClearIgnoreImag();
404   TestAndClearIgnoreRealAssign();
405   TestAndClearIgnoreImagAssign();
406   // ~(a+ib) = a + i*-b
407   ComplexPairTy Op = Visit(E->getSubExpr());
408   llvm::Value *ResI;
409   if (Op.second->getType()->isFloatingPointTy())
410     ResI = Builder.CreateFNeg(Op.second, "conj.i");
411   else
412     ResI = Builder.CreateNeg(Op.second, "conj.i");
413 
414   return ComplexPairTy(Op.first, ResI);
415 }
416 
417 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
418   llvm::Value *ResR, *ResI;
419 
420   if (Op.LHS.first->getType()->isFloatingPointTy()) {
421     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
422     ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
423   } else {
424     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
425     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
426   }
427   return ComplexPairTy(ResR, ResI);
428 }
429 
430 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
431   llvm::Value *ResR, *ResI;
432   if (Op.LHS.first->getType()->isFloatingPointTy()) {
433     ResR = Builder.CreateFSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
434     ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
435   } else {
436     ResR = Builder.CreateSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
437     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
438   }
439   return ComplexPairTy(ResR, ResI);
440 }
441 
442 
443 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
444   using llvm::Value;
445   Value *ResR, *ResI;
446 
447   if (Op.LHS.first->getType()->isFloatingPointTy()) {
448     Value *ResRl = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
449     Value *ResRr = Builder.CreateFMul(Op.LHS.second, Op.RHS.second,"mul.rr");
450     ResR  = Builder.CreateFSub(ResRl, ResRr, "mul.r");
451 
452     Value *ResIl = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il");
453     Value *ResIr = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
454     ResI  = Builder.CreateFAdd(ResIl, ResIr, "mul.i");
455   } else {
456     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
457     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
458     ResR  = Builder.CreateSub(ResRl, ResRr, "mul.r");
459 
460     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
461     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
462     ResI  = Builder.CreateAdd(ResIl, ResIr, "mul.i");
463   }
464   return ComplexPairTy(ResR, ResI);
465 }
466 
467 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
468   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
469   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
470 
471 
472   llvm::Value *DSTr, *DSTi;
473   if (Op.LHS.first->getType()->isFloatingPointTy()) {
474     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
475     llvm::Value *Tmp1 = Builder.CreateFMul(LHSr, RHSr, "tmp"); // a*c
476     llvm::Value *Tmp2 = Builder.CreateFMul(LHSi, RHSi, "tmp"); // b*d
477     llvm::Value *Tmp3 = Builder.CreateFAdd(Tmp1, Tmp2, "tmp"); // ac+bd
478 
479     llvm::Value *Tmp4 = Builder.CreateFMul(RHSr, RHSr, "tmp"); // c*c
480     llvm::Value *Tmp5 = Builder.CreateFMul(RHSi, RHSi, "tmp"); // d*d
481     llvm::Value *Tmp6 = Builder.CreateFAdd(Tmp4, Tmp5, "tmp"); // cc+dd
482 
483     llvm::Value *Tmp7 = Builder.CreateFMul(LHSi, RHSr, "tmp"); // b*c
484     llvm::Value *Tmp8 = Builder.CreateFMul(LHSr, RHSi, "tmp"); // a*d
485     llvm::Value *Tmp9 = Builder.CreateFSub(Tmp7, Tmp8, "tmp"); // bc-ad
486 
487     DSTr = Builder.CreateFDiv(Tmp3, Tmp6, "tmp");
488     DSTi = Builder.CreateFDiv(Tmp9, Tmp6, "tmp");
489   } else {
490     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
491     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr, "tmp"); // a*c
492     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi, "tmp"); // b*d
493     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2, "tmp"); // ac+bd
494 
495     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr, "tmp"); // c*c
496     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi, "tmp"); // d*d
497     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5, "tmp"); // cc+dd
498 
499     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr, "tmp"); // b*c
500     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi, "tmp"); // a*d
501     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8, "tmp"); // bc-ad
502 
503     if (Op.Ty->getAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
504       DSTr = Builder.CreateUDiv(Tmp3, Tmp6, "tmp");
505       DSTi = Builder.CreateUDiv(Tmp9, Tmp6, "tmp");
506     } else {
507       DSTr = Builder.CreateSDiv(Tmp3, Tmp6, "tmp");
508       DSTi = Builder.CreateSDiv(Tmp9, Tmp6, "tmp");
509     }
510   }
511 
512   return ComplexPairTy(DSTr, DSTi);
513 }
514 
515 ComplexExprEmitter::BinOpInfo
516 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
517   TestAndClearIgnoreReal();
518   TestAndClearIgnoreImag();
519   TestAndClearIgnoreRealAssign();
520   TestAndClearIgnoreImagAssign();
521   BinOpInfo Ops;
522   Ops.LHS = Visit(E->getLHS());
523   Ops.RHS = Visit(E->getRHS());
524   Ops.Ty = E->getType();
525   return Ops;
526 }
527 
528 
529 // Compound assignments.
530 ComplexPairTy ComplexExprEmitter::
531 EmitCompoundAssign(const CompoundAssignOperator *E,
532                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
533   TestAndClearIgnoreReal();
534   TestAndClearIgnoreImag();
535   bool ignreal = TestAndClearIgnoreRealAssign();
536   bool ignimag = TestAndClearIgnoreImagAssign();
537   QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType();
538 
539   BinOpInfo OpInfo;
540 
541   // Load the RHS and LHS operands.
542   // __block variables need to have the rhs evaluated first, plus this should
543   // improve codegen a little.  It is possible for the RHS to be complex or
544   // scalar.
545   OpInfo.Ty = E->getComputationResultType();
546   OpInfo.RHS = EmitCast(CK_Unknown, E->getRHS(), OpInfo.Ty);
547 
548   LValue LHS = CGF.EmitLValue(E->getLHS());
549   // We know the LHS is a complex lvalue.
550   ComplexPairTy LHSComplexPair;
551   if (LHS.isPropertyRef())
552     LHSComplexPair =
553       CGF.EmitObjCPropertyGet(LHS.getPropertyRefExpr()).getComplexVal();
554   else if (LHS.isKVCRef())
555     LHSComplexPair =
556       CGF.EmitObjCPropertyGet(LHS.getKVCRefExpr()).getComplexVal();
557   else
558     LHSComplexPair = EmitLoadOfComplex(LHS.getAddress(),
559                                        LHS.isVolatileQualified());
560 
561   OpInfo.LHS = EmitComplexToComplexCast(LHSComplexPair, LHSTy, OpInfo.Ty);
562 
563   // Expand the binary operator.
564   ComplexPairTy Result = (this->*Func)(OpInfo);
565 
566   // Truncate the result back to the LHS type.
567   Result = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
568 
569   // Store the result value into the LHS lvalue.
570   if (LHS.isPropertyRef())
571     CGF.EmitObjCPropertySet(LHS.getPropertyRefExpr(),
572                             RValue::getComplex(Result));
573   else if (LHS.isKVCRef())
574     CGF.EmitObjCPropertySet(LHS.getKVCRefExpr(), RValue::getComplex(Result));
575   else
576     EmitStoreOfComplex(Result, LHS.getAddress(), LHS.isVolatileQualified());
577 
578   // Restore the Ignore* flags.
579   IgnoreReal = ignreal;
580   IgnoreImag = ignimag;
581   IgnoreRealAssign = ignreal;
582   IgnoreImagAssign = ignimag;
583 
584   // Objective-C property assignment never reloads the value following a store.
585   if (LHS.isPropertyRef() || LHS.isKVCRef())
586     return Result;
587 
588   // Otherwise, reload the value.
589   return EmitLoadOfComplex(LHS.getAddress(), LHS.isVolatileQualified());
590 }
591 
592 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
593   TestAndClearIgnoreReal();
594   TestAndClearIgnoreImag();
595   bool ignreal = TestAndClearIgnoreRealAssign();
596   bool ignimag = TestAndClearIgnoreImagAssign();
597   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
598                                                  E->getRHS()->getType()) &&
599          "Invalid assignment");
600   // Emit the RHS.
601   ComplexPairTy Val = Visit(E->getRHS());
602 
603   // Compute the address to store into.
604   LValue LHS = CGF.EmitLValue(E->getLHS());
605 
606   // Store the result value into the LHS lvalue.
607   if (LHS.isPropertyRef())
608     CGF.EmitObjCPropertySet(LHS.getPropertyRefExpr(), RValue::getComplex(Val));
609   else if (LHS.isKVCRef())
610     CGF.EmitObjCPropertySet(LHS.getKVCRefExpr(), RValue::getComplex(Val));
611   else
612     EmitStoreOfComplex(Val, LHS.getAddress(), LHS.isVolatileQualified());
613 
614   // Restore the Ignore* flags.
615   IgnoreReal = ignreal;
616   IgnoreImag = ignimag;
617   IgnoreRealAssign = ignreal;
618   IgnoreImagAssign = ignimag;
619 
620   // Objective-C property assignment never reloads the value following a store.
621   if (LHS.isPropertyRef() || LHS.isKVCRef())
622     return Val;
623 
624   // Otherwise, reload the value.
625   return EmitLoadOfComplex(LHS.getAddress(), LHS.isVolatileQualified());
626 }
627 
628 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
629   CGF.EmitStmt(E->getLHS());
630   CGF.EnsureInsertPoint();
631   return Visit(E->getRHS());
632 }
633 
634 ComplexPairTy ComplexExprEmitter::
635 VisitConditionalOperator(const ConditionalOperator *E) {
636 
637   TestAndClearIgnoreReal();
638   TestAndClearIgnoreImag();
639   TestAndClearIgnoreRealAssign();
640   TestAndClearIgnoreImagAssign();
641   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
642   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
643   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
644 
645   if (E->getLHS())
646     CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
647   else {
648     Expr *save = E->getSAVE();
649     assert(save && "VisitConditionalOperator - save is null");
650     // Intentianlly not doing direct assignment to ConditionalSaveExprs[save] !!
651     ComplexPairTy SaveVal = Visit(save);
652     CGF.ConditionalSaveComplexExprs[save] = SaveVal;
653     CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
654   }
655 
656   CGF.EmitBlock(LHSBlock);
657   ComplexPairTy LHS = Visit(E->getTrueExpr());
658   LHSBlock = Builder.GetInsertBlock();
659   CGF.EmitBranch(ContBlock);
660 
661   CGF.EmitBlock(RHSBlock);
662 
663   ComplexPairTy RHS = Visit(E->getRHS());
664   RHSBlock = Builder.GetInsertBlock();
665   CGF.EmitBranch(ContBlock);
666 
667   CGF.EmitBlock(ContBlock);
668 
669   // Create a PHI node for the real part.
670   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), "cond.r");
671   RealPN->reserveOperandSpace(2);
672   RealPN->addIncoming(LHS.first, LHSBlock);
673   RealPN->addIncoming(RHS.first, RHSBlock);
674 
675   // Create a PHI node for the imaginary part.
676   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), "cond.i");
677   ImagPN->reserveOperandSpace(2);
678   ImagPN->addIncoming(LHS.second, LHSBlock);
679   ImagPN->addIncoming(RHS.second, RHSBlock);
680 
681   return ComplexPairTy(RealPN, ImagPN);
682 }
683 
684 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
685   return Visit(E->getChosenSubExpr(CGF.getContext()));
686 }
687 
688 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
689     bool Ignore = TestAndClearIgnoreReal();
690     (void)Ignore;
691     assert (Ignore == false && "init list ignored");
692     Ignore = TestAndClearIgnoreImag();
693     (void)Ignore;
694     assert (Ignore == false && "init list ignored");
695   if (E->getNumInits())
696     return Visit(E->getInit(0));
697 
698   // Empty init list intializes to null
699   QualType Ty = E->getType()->getAs<ComplexType>()->getElementType();
700   const llvm::Type* LTy = CGF.ConvertType(Ty);
701   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
702   return ComplexPairTy(zeroConstant, zeroConstant);
703 }
704 
705 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
706   llvm::Value *ArgValue = CGF.EmitVAListRef(E->getSubExpr());
707   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, E->getType());
708 
709   if (!ArgPtr) {
710     CGF.ErrorUnsupported(E, "complex va_arg expression");
711     const llvm::Type *EltTy =
712       CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
713     llvm::Value *U = llvm::UndefValue::get(EltTy);
714     return ComplexPairTy(U, U);
715   }
716 
717   // FIXME Volatility.
718   return EmitLoadOfComplex(ArgPtr, false);
719 }
720 
721 //===----------------------------------------------------------------------===//
722 //                         Entry Point into this File
723 //===----------------------------------------------------------------------===//
724 
725 /// EmitComplexExpr - Emit the computation of the specified expression of
726 /// complex type, ignoring the result.
727 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
728                                                bool IgnoreImag, bool IgnoreRealAssign, bool IgnoreImagAssign) {
729   assert(E && E->getType()->isAnyComplexType() &&
730          "Invalid complex expression to emit");
731 
732   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag, IgnoreRealAssign,
733                             IgnoreImagAssign)
734     .Visit(const_cast<Expr*>(E));
735 }
736 
737 /// EmitComplexExprIntoAddr - Emit the computation of the specified expression
738 /// of complex type, storing into the specified Value*.
739 void CodeGenFunction::EmitComplexExprIntoAddr(const Expr *E,
740                                               llvm::Value *DestAddr,
741                                               bool DestIsVolatile) {
742   assert(E && E->getType()->isAnyComplexType() &&
743          "Invalid complex expression to emit");
744   ComplexExprEmitter Emitter(*this);
745   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
746   Emitter.EmitStoreOfComplex(Val, DestAddr, DestIsVolatile);
747 }
748 
749 /// StoreComplexToAddr - Store a complex number into the specified address.
750 void CodeGenFunction::StoreComplexToAddr(ComplexPairTy V,
751                                          llvm::Value *DestAddr,
752                                          bool DestIsVolatile) {
753   ComplexExprEmitter(*this).EmitStoreOfComplex(V, DestAddr, DestIsVolatile);
754 }
755 
756 /// LoadComplexFromAddr - Load a complex number from the specified address.
757 ComplexPairTy CodeGenFunction::LoadComplexFromAddr(llvm::Value *SrcAddr,
758                                                    bool SrcIsVolatile) {
759   return ComplexExprEmitter(*this).EmitLoadOfComplex(SrcAddr, SrcIsVolatile);
760 }
761