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   // Two cases here: cast from (complex to complex) and (scalar to complex).
354   if (Op->getType()->isAnyComplexType())
355     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
356 
357   // FIXME: We should be looking at all of the cast kinds here, not
358   // cherry-picking the ones we have test cases for.
359   if (CK == CK_LValueBitCast) {
360     llvm::Value *V = CGF.EmitLValue(Op).getAddress();
361     V = Builder.CreateBitCast(V,
362                       CGF.ConvertType(CGF.getContext().getPointerType(DestTy)));
363     // FIXME: Are the qualifiers correct here?
364     return EmitLoadOfComplex(V, DestTy.isVolatileQualified());
365   }
366 
367   // C99 6.3.1.7: When a value of real type is converted to a complex type, the
368   // real part of the complex result value is determined by the rules of
369   // conversion to the corresponding real type and the imaginary part of the
370   // complex result value is a positive zero or an unsigned zero.
371   llvm::Value *Elt = CGF.EmitScalarExpr(Op);
372 
373   // Convert the input element to the element type of the complex.
374   DestTy = DestTy->getAs<ComplexType>()->getElementType();
375   Elt = CGF.EmitScalarConversion(Elt, Op->getType(), DestTy);
376 
377   // Return (realval, 0).
378   return ComplexPairTy(Elt, llvm::Constant::getNullValue(Elt->getType()));
379 }
380 
381 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
382   TestAndClearIgnoreReal();
383   TestAndClearIgnoreImag();
384   TestAndClearIgnoreRealAssign();
385   TestAndClearIgnoreImagAssign();
386   ComplexPairTy Op = Visit(E->getSubExpr());
387 
388   llvm::Value *ResR, *ResI;
389   if (Op.first->getType()->isFloatingPointTy()) {
390     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
391     ResI = Builder.CreateFNeg(Op.second, "neg.i");
392   } else {
393     ResR = Builder.CreateNeg(Op.first,  "neg.r");
394     ResI = Builder.CreateNeg(Op.second, "neg.i");
395   }
396   return ComplexPairTy(ResR, ResI);
397 }
398 
399 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
400   TestAndClearIgnoreReal();
401   TestAndClearIgnoreImag();
402   TestAndClearIgnoreRealAssign();
403   TestAndClearIgnoreImagAssign();
404   // ~(a+ib) = a + i*-b
405   ComplexPairTy Op = Visit(E->getSubExpr());
406   llvm::Value *ResI;
407   if (Op.second->getType()->isFloatingPointTy())
408     ResI = Builder.CreateFNeg(Op.second, "conj.i");
409   else
410     ResI = Builder.CreateNeg(Op.second, "conj.i");
411 
412   return ComplexPairTy(Op.first, ResI);
413 }
414 
415 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
416   llvm::Value *ResR, *ResI;
417 
418   if (Op.LHS.first->getType()->isFloatingPointTy()) {
419     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
420     ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
421   } else {
422     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
423     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
424   }
425   return ComplexPairTy(ResR, ResI);
426 }
427 
428 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
429   llvm::Value *ResR, *ResI;
430   if (Op.LHS.first->getType()->isFloatingPointTy()) {
431     ResR = Builder.CreateFSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
432     ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
433   } else {
434     ResR = Builder.CreateSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
435     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
436   }
437   return ComplexPairTy(ResR, ResI);
438 }
439 
440 
441 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
442   using llvm::Value;
443   Value *ResR, *ResI;
444 
445   if (Op.LHS.first->getType()->isFloatingPointTy()) {
446     Value *ResRl = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
447     Value *ResRr = Builder.CreateFMul(Op.LHS.second, Op.RHS.second,"mul.rr");
448     ResR  = Builder.CreateFSub(ResRl, ResRr, "mul.r");
449 
450     Value *ResIl = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il");
451     Value *ResIr = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
452     ResI  = Builder.CreateFAdd(ResIl, ResIr, "mul.i");
453   } else {
454     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
455     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
456     ResR  = Builder.CreateSub(ResRl, ResRr, "mul.r");
457 
458     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
459     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
460     ResI  = Builder.CreateAdd(ResIl, ResIr, "mul.i");
461   }
462   return ComplexPairTy(ResR, ResI);
463 }
464 
465 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
466   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
467   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
468 
469 
470   llvm::Value *DSTr, *DSTi;
471   if (Op.LHS.first->getType()->isFloatingPointTy()) {
472     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
473     llvm::Value *Tmp1 = Builder.CreateFMul(LHSr, RHSr, "tmp"); // a*c
474     llvm::Value *Tmp2 = Builder.CreateFMul(LHSi, RHSi, "tmp"); // b*d
475     llvm::Value *Tmp3 = Builder.CreateFAdd(Tmp1, Tmp2, "tmp"); // ac+bd
476 
477     llvm::Value *Tmp4 = Builder.CreateFMul(RHSr, RHSr, "tmp"); // c*c
478     llvm::Value *Tmp5 = Builder.CreateFMul(RHSi, RHSi, "tmp"); // d*d
479     llvm::Value *Tmp6 = Builder.CreateFAdd(Tmp4, Tmp5, "tmp"); // cc+dd
480 
481     llvm::Value *Tmp7 = Builder.CreateFMul(LHSi, RHSr, "tmp"); // b*c
482     llvm::Value *Tmp8 = Builder.CreateFMul(LHSr, RHSi, "tmp"); // a*d
483     llvm::Value *Tmp9 = Builder.CreateFSub(Tmp7, Tmp8, "tmp"); // bc-ad
484 
485     DSTr = Builder.CreateFDiv(Tmp3, Tmp6, "tmp");
486     DSTi = Builder.CreateFDiv(Tmp9, Tmp6, "tmp");
487   } else {
488     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
489     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr, "tmp"); // a*c
490     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi, "tmp"); // b*d
491     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2, "tmp"); // ac+bd
492 
493     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr, "tmp"); // c*c
494     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi, "tmp"); // d*d
495     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5, "tmp"); // cc+dd
496 
497     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr, "tmp"); // b*c
498     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi, "tmp"); // a*d
499     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8, "tmp"); // bc-ad
500 
501     if (Op.Ty->getAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
502       DSTr = Builder.CreateUDiv(Tmp3, Tmp6, "tmp");
503       DSTi = Builder.CreateUDiv(Tmp9, Tmp6, "tmp");
504     } else {
505       DSTr = Builder.CreateSDiv(Tmp3, Tmp6, "tmp");
506       DSTi = Builder.CreateSDiv(Tmp9, Tmp6, "tmp");
507     }
508   }
509 
510   return ComplexPairTy(DSTr, DSTi);
511 }
512 
513 ComplexExprEmitter::BinOpInfo
514 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
515   TestAndClearIgnoreReal();
516   TestAndClearIgnoreImag();
517   TestAndClearIgnoreRealAssign();
518   TestAndClearIgnoreImagAssign();
519   BinOpInfo Ops;
520   Ops.LHS = Visit(E->getLHS());
521   Ops.RHS = Visit(E->getRHS());
522   Ops.Ty = E->getType();
523   return Ops;
524 }
525 
526 
527 // Compound assignments.
528 ComplexPairTy ComplexExprEmitter::
529 EmitCompoundAssign(const CompoundAssignOperator *E,
530                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
531   TestAndClearIgnoreReal();
532   TestAndClearIgnoreImag();
533   bool ignreal = TestAndClearIgnoreRealAssign();
534   bool ignimag = TestAndClearIgnoreImagAssign();
535   QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType();
536 
537   BinOpInfo OpInfo;
538 
539   // Load the RHS and LHS operands.
540   // __block variables need to have the rhs evaluated first, plus this should
541   // improve codegen a little.  It is possible for the RHS to be complex or
542   // scalar.
543   OpInfo.Ty = E->getComputationResultType();
544   OpInfo.RHS = EmitCast(CK_Unknown, E->getRHS(), OpInfo.Ty);
545 
546   LValue LHS = CGF.EmitLValue(E->getLHS());
547   // We know the LHS is a complex lvalue.
548   ComplexPairTy LHSComplexPair;
549   if (LHS.isPropertyRef())
550     LHSComplexPair =
551       CGF.EmitObjCPropertyGet(LHS.getPropertyRefExpr()).getComplexVal();
552   else if (LHS.isKVCRef())
553     LHSComplexPair =
554       CGF.EmitObjCPropertyGet(LHS.getKVCRefExpr()).getComplexVal();
555   else
556     LHSComplexPair = EmitLoadOfComplex(LHS.getAddress(),
557                                        LHS.isVolatileQualified());
558 
559   OpInfo.LHS = EmitComplexToComplexCast(LHSComplexPair, LHSTy, OpInfo.Ty);
560 
561   // Expand the binary operator.
562   ComplexPairTy Result = (this->*Func)(OpInfo);
563 
564   // Truncate the result back to the LHS type.
565   Result = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
566 
567   // Store the result value into the LHS lvalue.
568   if (LHS.isPropertyRef())
569     CGF.EmitObjCPropertySet(LHS.getPropertyRefExpr(),
570                             RValue::getComplex(Result));
571   else if (LHS.isKVCRef())
572     CGF.EmitObjCPropertySet(LHS.getKVCRefExpr(), RValue::getComplex(Result));
573   else
574     EmitStoreOfComplex(Result, LHS.getAddress(), LHS.isVolatileQualified());
575 
576   // Restore the Ignore* flags.
577   IgnoreReal = ignreal;
578   IgnoreImag = ignimag;
579   IgnoreRealAssign = ignreal;
580   IgnoreImagAssign = ignimag;
581 
582   // Objective-C property assignment never reloads the value following a store.
583   if (LHS.isPropertyRef() || LHS.isKVCRef())
584     return Result;
585 
586   // Otherwise, reload the value.
587   return EmitLoadOfComplex(LHS.getAddress(), LHS.isVolatileQualified());
588 }
589 
590 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
591   TestAndClearIgnoreReal();
592   TestAndClearIgnoreImag();
593   bool ignreal = TestAndClearIgnoreRealAssign();
594   bool ignimag = TestAndClearIgnoreImagAssign();
595   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
596                                                  E->getRHS()->getType()) &&
597          "Invalid assignment");
598   // Emit the RHS.
599   ComplexPairTy Val = Visit(E->getRHS());
600 
601   // Compute the address to store into.
602   LValue LHS = CGF.EmitLValue(E->getLHS());
603 
604   // Store the result value into the LHS lvalue.
605   if (LHS.isPropertyRef())
606     CGF.EmitObjCPropertySet(LHS.getPropertyRefExpr(), RValue::getComplex(Val));
607   else if (LHS.isKVCRef())
608     CGF.EmitObjCPropertySet(LHS.getKVCRefExpr(), RValue::getComplex(Val));
609   else
610     EmitStoreOfComplex(Val, LHS.getAddress(), LHS.isVolatileQualified());
611 
612   // Restore the Ignore* flags.
613   IgnoreReal = ignreal;
614   IgnoreImag = ignimag;
615   IgnoreRealAssign = ignreal;
616   IgnoreImagAssign = ignimag;
617 
618   // Objective-C property assignment never reloads the value following a store.
619   if (LHS.isPropertyRef() || LHS.isKVCRef())
620     return Val;
621 
622   // Otherwise, reload the value.
623   return EmitLoadOfComplex(LHS.getAddress(), LHS.isVolatileQualified());
624 }
625 
626 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
627   CGF.EmitStmt(E->getLHS());
628   CGF.EnsureInsertPoint();
629   return Visit(E->getRHS());
630 }
631 
632 ComplexPairTy ComplexExprEmitter::
633 VisitConditionalOperator(const ConditionalOperator *E) {
634 
635   TestAndClearIgnoreReal();
636   TestAndClearIgnoreImag();
637   TestAndClearIgnoreRealAssign();
638   TestAndClearIgnoreImagAssign();
639   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
640   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
641   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
642 
643   if (E->getLHS())
644     CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
645   else {
646     Expr *save = E->getSAVE();
647     assert(save && "VisitConditionalOperator - save is null");
648     // Intentianlly not doing direct assignment to ConditionalSaveExprs[save] !!
649     ComplexPairTy SaveVal = Visit(save);
650     CGF.ConditionalSaveComplexExprs[save] = SaveVal;
651     CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
652   }
653 
654   CGF.EmitBlock(LHSBlock);
655   ComplexPairTy LHS = Visit(E->getTrueExpr());
656   LHSBlock = Builder.GetInsertBlock();
657   CGF.EmitBranch(ContBlock);
658 
659   CGF.EmitBlock(RHSBlock);
660 
661   ComplexPairTy RHS = Visit(E->getRHS());
662   RHSBlock = Builder.GetInsertBlock();
663   CGF.EmitBranch(ContBlock);
664 
665   CGF.EmitBlock(ContBlock);
666 
667   // Create a PHI node for the real part.
668   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), "cond.r");
669   RealPN->reserveOperandSpace(2);
670   RealPN->addIncoming(LHS.first, LHSBlock);
671   RealPN->addIncoming(RHS.first, RHSBlock);
672 
673   // Create a PHI node for the imaginary part.
674   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), "cond.i");
675   ImagPN->reserveOperandSpace(2);
676   ImagPN->addIncoming(LHS.second, LHSBlock);
677   ImagPN->addIncoming(RHS.second, RHSBlock);
678 
679   return ComplexPairTy(RealPN, ImagPN);
680 }
681 
682 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
683   return Visit(E->getChosenSubExpr(CGF.getContext()));
684 }
685 
686 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
687     bool Ignore = TestAndClearIgnoreReal();
688     (void)Ignore;
689     assert (Ignore == false && "init list ignored");
690     Ignore = TestAndClearIgnoreImag();
691     (void)Ignore;
692     assert (Ignore == false && "init list ignored");
693   if (E->getNumInits())
694     return Visit(E->getInit(0));
695 
696   // Empty init list intializes to null
697   QualType Ty = E->getType()->getAs<ComplexType>()->getElementType();
698   const llvm::Type* LTy = CGF.ConvertType(Ty);
699   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
700   return ComplexPairTy(zeroConstant, zeroConstant);
701 }
702 
703 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
704   llvm::Value *ArgValue = CGF.EmitVAListRef(E->getSubExpr());
705   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, E->getType());
706 
707   if (!ArgPtr) {
708     CGF.ErrorUnsupported(E, "complex va_arg expression");
709     const llvm::Type *EltTy =
710       CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
711     llvm::Value *U = llvm::UndefValue::get(EltTy);
712     return ComplexPairTy(U, U);
713   }
714 
715   // FIXME Volatility.
716   return EmitLoadOfComplex(ArgPtr, false);
717 }
718 
719 //===----------------------------------------------------------------------===//
720 //                         Entry Point into this File
721 //===----------------------------------------------------------------------===//
722 
723 /// EmitComplexExpr - Emit the computation of the specified expression of
724 /// complex type, ignoring the result.
725 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
726                                                bool IgnoreImag, bool IgnoreRealAssign, bool IgnoreImagAssign) {
727   assert(E && E->getType()->isAnyComplexType() &&
728          "Invalid complex expression to emit");
729 
730   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag, IgnoreRealAssign,
731                             IgnoreImagAssign)
732     .Visit(const_cast<Expr*>(E));
733 }
734 
735 /// EmitComplexExprIntoAddr - Emit the computation of the specified expression
736 /// of complex type, storing into the specified Value*.
737 void CodeGenFunction::EmitComplexExprIntoAddr(const Expr *E,
738                                               llvm::Value *DestAddr,
739                                               bool DestIsVolatile) {
740   assert(E && E->getType()->isAnyComplexType() &&
741          "Invalid complex expression to emit");
742   ComplexExprEmitter Emitter(*this);
743   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
744   Emitter.EmitStoreOfComplex(Val, DestAddr, DestIsVolatile);
745 }
746 
747 /// StoreComplexToAddr - Store a complex number into the specified address.
748 void CodeGenFunction::StoreComplexToAddr(ComplexPairTy V,
749                                          llvm::Value *DestAddr,
750                                          bool DestIsVolatile) {
751   ComplexExprEmitter(*this).EmitStoreOfComplex(V, DestAddr, DestIsVolatile);
752 }
753 
754 /// LoadComplexFromAddr - Load a complex number from the specified address.
755 ComplexPairTy CodeGenFunction::LoadComplexFromAddr(llvm::Value *SrcAddr,
756                                                    bool SrcIsVolatile) {
757   return ComplexExprEmitter(*this).EmitLoadOfComplex(SrcAddr, SrcIsVolatile);
758 }
759