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     LValue LV = CGF.EmitLValue(E);
64     if (LV.isSimple())
65       return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
66 
67     if (LV.isPropertyRef())
68       return CGF.EmitObjCPropertyGet(LV.getPropertyRefExpr()).getComplexVal();
69 
70     assert(LV.isKVCRef() && "Unknown LValue type!");
71     return CGF.EmitObjCPropertyGet(LV.getKVCRefExpr()).getComplexVal();
72   }
73 
74   /// EmitLoadOfComplex - Given a pointer to a complex value, emit code to load
75   /// the real and imaginary pieces.
76   ComplexPairTy EmitLoadOfComplex(llvm::Value *SrcPtr, bool isVolatile);
77 
78   /// EmitStoreOfComplex - Store the specified real/imag parts into the
79   /// specified value pointer.
80   void EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *ResPtr, bool isVol);
81 
82   /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
83   ComplexPairTy EmitComplexToComplexCast(ComplexPairTy Val, QualType SrcType,
84                                          QualType DestType);
85 
86   //===--------------------------------------------------------------------===//
87   //                            Visitor Methods
88   //===--------------------------------------------------------------------===//
89 
90   ComplexPairTy Visit(Expr *E) {
91     llvm::DenseMap<const Expr *, ComplexPairTy>::iterator I =
92       CGF.ConditionalSaveComplexExprs.find(E);
93     if (I != CGF.ConditionalSaveComplexExprs.end())
94       return I->second;
95 
96       return StmtVisitor<ComplexExprEmitter, ComplexPairTy>::Visit(E);
97   }
98 
99   ComplexPairTy VisitStmt(Stmt *S) {
100     S->dump(CGF.getContext().getSourceManager());
101     assert(0 && "Stmt can't have complex result type!");
102     return ComplexPairTy();
103   }
104   ComplexPairTy VisitExpr(Expr *S);
105   ComplexPairTy VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr());}
106   ComplexPairTy VisitImaginaryLiteral(const ImaginaryLiteral *IL);
107 
108   // l-values.
109   ComplexPairTy VisitDeclRefExpr(const Expr *E) { return EmitLoadOfLValue(E); }
110   ComplexPairTy VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
111     return EmitLoadOfLValue(E);
112   }
113   ComplexPairTy VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
114     return EmitLoadOfLValue(E);
115   }
116   ComplexPairTy VisitObjCImplicitSetterGetterRefExpr(
117                                ObjCImplicitSetterGetterRefExpr *E) {
118     return EmitLoadOfLValue(E);
119   }
120   ComplexPairTy VisitObjCMessageExpr(ObjCMessageExpr *E) {
121     return CGF.EmitObjCMessageExpr(E).getComplexVal();
122   }
123   ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
124   ComplexPairTy VisitMemberExpr(const Expr *E) { return EmitLoadOfLValue(E); }
125 
126   // FIXME: CompoundLiteralExpr
127 
128   ComplexPairTy EmitCast(CastExpr::CastKind CK, Expr *Op, QualType DestTy);
129   ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
130     // Unlike for scalars, we don't have to worry about function->ptr demotion
131     // here.
132     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
133   }
134   ComplexPairTy VisitCastExpr(CastExpr *E) {
135     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
136   }
137   ComplexPairTy VisitCallExpr(const CallExpr *E);
138   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
139 
140   // Operators.
141   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
142                                    bool isInc, bool isPre) {
143     LValue LV = CGF.EmitLValue(E->getSubExpr());
144     return CGF.EmitComplexPrePostIncDec(E, LV, isInc, isPre);
145   }
146   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
147     return VisitPrePostIncDec(E, false, false);
148   }
149   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
150     return VisitPrePostIncDec(E, true, false);
151   }
152   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
153     return VisitPrePostIncDec(E, false, true);
154   }
155   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
156     return VisitPrePostIncDec(E, true, true);
157   }
158   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
159   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
160     TestAndClearIgnoreReal();
161     TestAndClearIgnoreImag();
162     return Visit(E->getSubExpr());
163   }
164   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
165   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
166   // LNot,Real,Imag never return complex.
167   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
168     return Visit(E->getSubExpr());
169   }
170   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
171     return Visit(DAE->getExpr());
172   }
173   ComplexPairTy VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) {
174     return CGF.EmitCXXExprWithTemporaries(E).getComplexVal();
175   }
176   ComplexPairTy VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
177     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
178     QualType Elem = E->getType()->getAs<ComplexType>()->getElementType();
179     llvm::Constant *Null = llvm::Constant::getNullValue(CGF.ConvertType(Elem));
180     return ComplexPairTy(Null, Null);
181   }
182   ComplexPairTy VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
183     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
184     QualType Elem = E->getType()->getAs<ComplexType>()->getElementType();
185     llvm::Constant *Null =
186                        llvm::Constant::getNullValue(CGF.ConvertType(Elem));
187     return ComplexPairTy(Null, Null);
188   }
189 
190   struct BinOpInfo {
191     ComplexPairTy LHS;
192     ComplexPairTy RHS;
193     QualType Ty;  // Computation Type.
194   };
195 
196   BinOpInfo EmitBinOps(const BinaryOperator *E);
197   LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
198                                   ComplexPairTy (ComplexExprEmitter::*Func)
199                                   (const BinOpInfo &),
200                                   ComplexPairTy &Val);
201   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
202                                    ComplexPairTy (ComplexExprEmitter::*Func)
203                                    (const BinOpInfo &));
204 
205   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
206   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
207   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
208   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
209 
210   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
211     return EmitBinAdd(EmitBinOps(E));
212   }
213   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
214     return EmitBinSub(EmitBinOps(E));
215   }
216   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
217     return EmitBinMul(EmitBinOps(E));
218   }
219   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
220     return EmitBinDiv(EmitBinOps(E));
221   }
222 
223   // Compound assignments.
224   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
225     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
226   }
227   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
228     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
229   }
230   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
231     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
232   }
233   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
234     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
235   }
236 
237   // GCC rejects rem/and/or/xor for integer complex.
238   // Logical and/or always return int, never complex.
239 
240   // No comparisons produce a complex result.
241 
242   LValue EmitBinAssignLValue(const BinaryOperator *E,
243                              ComplexPairTy &Val);
244   ComplexPairTy VisitBinAssign     (const BinaryOperator *E);
245   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
246 
247 
248   ComplexPairTy VisitConditionalOperator(const ConditionalOperator *CO);
249   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
250 
251   ComplexPairTy VisitInitListExpr(InitListExpr *E);
252 
253   ComplexPairTy VisitVAArgExpr(VAArgExpr *E);
254 };
255 }  // end anonymous namespace.
256 
257 //===----------------------------------------------------------------------===//
258 //                                Utilities
259 //===----------------------------------------------------------------------===//
260 
261 /// EmitLoadOfComplex - Given an RValue reference for a complex, emit code to
262 /// load the real and imaginary pieces, returning them as Real/Imag.
263 ComplexPairTy ComplexExprEmitter::EmitLoadOfComplex(llvm::Value *SrcPtr,
264                                                     bool isVolatile) {
265   llvm::Value *Real=0, *Imag=0;
266 
267   if (!IgnoreReal || isVolatile) {
268     llvm::Value *RealP = Builder.CreateStructGEP(SrcPtr, 0,
269                                                  SrcPtr->getName() + ".realp");
270     Real = Builder.CreateLoad(RealP, isVolatile, SrcPtr->getName() + ".real");
271   }
272 
273   if (!IgnoreImag || isVolatile) {
274     llvm::Value *ImagP = Builder.CreateStructGEP(SrcPtr, 1,
275                                                  SrcPtr->getName() + ".imagp");
276     Imag = Builder.CreateLoad(ImagP, isVolatile, SrcPtr->getName() + ".imag");
277   }
278   return ComplexPairTy(Real, Imag);
279 }
280 
281 /// EmitStoreOfComplex - Store the specified real/imag parts into the
282 /// specified value pointer.
283 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *Ptr,
284                                             bool isVolatile) {
285   llvm::Value *RealPtr = Builder.CreateStructGEP(Ptr, 0, "real");
286   llvm::Value *ImagPtr = Builder.CreateStructGEP(Ptr, 1, "imag");
287 
288   Builder.CreateStore(Val.first, RealPtr, isVolatile);
289   Builder.CreateStore(Val.second, ImagPtr, isVolatile);
290 }
291 
292 
293 
294 //===----------------------------------------------------------------------===//
295 //                            Visitor Methods
296 //===----------------------------------------------------------------------===//
297 
298 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
299   CGF.ErrorUnsupported(E, "complex expression");
300   const llvm::Type *EltTy =
301     CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
302   llvm::Value *U = llvm::UndefValue::get(EltTy);
303   return ComplexPairTy(U, U);
304 }
305 
306 ComplexPairTy ComplexExprEmitter::
307 VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
308   llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
309   return
310         ComplexPairTy(llvm::Constant::getNullValue(Imag->getType()), Imag);
311 }
312 
313 
314 ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
315   if (E->getCallReturnType()->isReferenceType())
316     return EmitLoadOfLValue(E);
317 
318   return CGF.EmitCallExpr(E).getComplexVal();
319 }
320 
321 ComplexPairTy ComplexExprEmitter::VisitStmtExpr(const StmtExpr *E) {
322   return CGF.EmitCompoundStmt(*E->getSubStmt(), true).getComplexVal();
323 }
324 
325 /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
326 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
327                                                            QualType SrcType,
328                                                            QualType DestType) {
329   // Get the src/dest element type.
330   SrcType = SrcType->getAs<ComplexType>()->getElementType();
331   DestType = DestType->getAs<ComplexType>()->getElementType();
332 
333   // C99 6.3.1.6: When a value of complex type is converted to another
334   // complex type, both the real and imaginary parts follow the conversion
335   // rules for the corresponding real types.
336   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType);
337   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType);
338   return Val;
339 }
340 
341 ComplexPairTy ComplexExprEmitter::EmitCast(CastExpr::CastKind CK, Expr *Op,
342                                            QualType DestTy) {
343   // FIXME: this should be based off of the CastKind.
344 
345   // Two cases here: cast from (complex to complex) and (scalar to complex).
346   if (Op->getType()->isAnyComplexType())
347     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
348 
349   // FIXME: We should be looking at all of the cast kinds here, not
350   // cherry-picking the ones we have test cases for.
351   if (CK == CK_LValueBitCast) {
352     llvm::Value *V = CGF.EmitLValue(Op).getAddress();
353     V = Builder.CreateBitCast(V,
354                       CGF.ConvertType(CGF.getContext().getPointerType(DestTy)));
355     // FIXME: Are the qualifiers correct here?
356     return EmitLoadOfComplex(V, DestTy.isVolatileQualified());
357   }
358 
359   // C99 6.3.1.7: When a value of real type is converted to a complex type, the
360   // real part of the complex result value is determined by the rules of
361   // conversion to the corresponding real type and the imaginary part of the
362   // complex result value is a positive zero or an unsigned zero.
363   llvm::Value *Elt = CGF.EmitScalarExpr(Op);
364 
365   // Convert the input element to the element type of the complex.
366   DestTy = DestTy->getAs<ComplexType>()->getElementType();
367   Elt = CGF.EmitScalarConversion(Elt, Op->getType(), DestTy);
368 
369   // Return (realval, 0).
370   return ComplexPairTy(Elt, llvm::Constant::getNullValue(Elt->getType()));
371 }
372 
373 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
374   TestAndClearIgnoreReal();
375   TestAndClearIgnoreImag();
376   ComplexPairTy Op = Visit(E->getSubExpr());
377 
378   llvm::Value *ResR, *ResI;
379   if (Op.first->getType()->isFloatingPointTy()) {
380     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
381     ResI = Builder.CreateFNeg(Op.second, "neg.i");
382   } else {
383     ResR = Builder.CreateNeg(Op.first,  "neg.r");
384     ResI = Builder.CreateNeg(Op.second, "neg.i");
385   }
386   return ComplexPairTy(ResR, ResI);
387 }
388 
389 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
390   TestAndClearIgnoreReal();
391   TestAndClearIgnoreImag();
392   // ~(a+ib) = a + i*-b
393   ComplexPairTy Op = Visit(E->getSubExpr());
394   llvm::Value *ResI;
395   if (Op.second->getType()->isFloatingPointTy())
396     ResI = Builder.CreateFNeg(Op.second, "conj.i");
397   else
398     ResI = Builder.CreateNeg(Op.second, "conj.i");
399 
400   return ComplexPairTy(Op.first, ResI);
401 }
402 
403 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
404   llvm::Value *ResR, *ResI;
405 
406   if (Op.LHS.first->getType()->isFloatingPointTy()) {
407     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
408     ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
409   } else {
410     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
411     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
412   }
413   return ComplexPairTy(ResR, ResI);
414 }
415 
416 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
417   llvm::Value *ResR, *ResI;
418   if (Op.LHS.first->getType()->isFloatingPointTy()) {
419     ResR = Builder.CreateFSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
420     ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
421   } else {
422     ResR = Builder.CreateSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
423     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
424   }
425   return ComplexPairTy(ResR, ResI);
426 }
427 
428 
429 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
430   using llvm::Value;
431   Value *ResR, *ResI;
432 
433   if (Op.LHS.first->getType()->isFloatingPointTy()) {
434     Value *ResRl = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
435     Value *ResRr = Builder.CreateFMul(Op.LHS.second, Op.RHS.second,"mul.rr");
436     ResR  = Builder.CreateFSub(ResRl, ResRr, "mul.r");
437 
438     Value *ResIl = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il");
439     Value *ResIr = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
440     ResI  = Builder.CreateFAdd(ResIl, ResIr, "mul.i");
441   } else {
442     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
443     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
444     ResR  = Builder.CreateSub(ResRl, ResRr, "mul.r");
445 
446     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
447     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
448     ResI  = Builder.CreateAdd(ResIl, ResIr, "mul.i");
449   }
450   return ComplexPairTy(ResR, ResI);
451 }
452 
453 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
454   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
455   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
456 
457 
458   llvm::Value *DSTr, *DSTi;
459   if (Op.LHS.first->getType()->isFloatingPointTy()) {
460     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
461     llvm::Value *Tmp1 = Builder.CreateFMul(LHSr, RHSr, "tmp"); // a*c
462     llvm::Value *Tmp2 = Builder.CreateFMul(LHSi, RHSi, "tmp"); // b*d
463     llvm::Value *Tmp3 = Builder.CreateFAdd(Tmp1, Tmp2, "tmp"); // ac+bd
464 
465     llvm::Value *Tmp4 = Builder.CreateFMul(RHSr, RHSr, "tmp"); // c*c
466     llvm::Value *Tmp5 = Builder.CreateFMul(RHSi, RHSi, "tmp"); // d*d
467     llvm::Value *Tmp6 = Builder.CreateFAdd(Tmp4, Tmp5, "tmp"); // cc+dd
468 
469     llvm::Value *Tmp7 = Builder.CreateFMul(LHSi, RHSr, "tmp"); // b*c
470     llvm::Value *Tmp8 = Builder.CreateFMul(LHSr, RHSi, "tmp"); // a*d
471     llvm::Value *Tmp9 = Builder.CreateFSub(Tmp7, Tmp8, "tmp"); // bc-ad
472 
473     DSTr = Builder.CreateFDiv(Tmp3, Tmp6, "tmp");
474     DSTi = Builder.CreateFDiv(Tmp9, Tmp6, "tmp");
475   } else {
476     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
477     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr, "tmp"); // a*c
478     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi, "tmp"); // b*d
479     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2, "tmp"); // ac+bd
480 
481     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr, "tmp"); // c*c
482     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi, "tmp"); // d*d
483     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5, "tmp"); // cc+dd
484 
485     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr, "tmp"); // b*c
486     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi, "tmp"); // a*d
487     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8, "tmp"); // bc-ad
488 
489     if (Op.Ty->getAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
490       DSTr = Builder.CreateUDiv(Tmp3, Tmp6, "tmp");
491       DSTi = Builder.CreateUDiv(Tmp9, Tmp6, "tmp");
492     } else {
493       DSTr = Builder.CreateSDiv(Tmp3, Tmp6, "tmp");
494       DSTi = Builder.CreateSDiv(Tmp9, Tmp6, "tmp");
495     }
496   }
497 
498   return ComplexPairTy(DSTr, DSTi);
499 }
500 
501 ComplexExprEmitter::BinOpInfo
502 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
503   TestAndClearIgnoreReal();
504   TestAndClearIgnoreImag();
505   BinOpInfo Ops;
506   Ops.LHS = Visit(E->getLHS());
507   Ops.RHS = Visit(E->getRHS());
508   Ops.Ty = E->getType();
509   return Ops;
510 }
511 
512 
513 LValue ComplexExprEmitter::
514 EmitCompoundAssignLValue(const CompoundAssignOperator *E,
515           ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&),
516                          ComplexPairTy &Val) {
517   TestAndClearIgnoreReal();
518   TestAndClearIgnoreImag();
519   QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType();
520 
521   BinOpInfo OpInfo;
522 
523   // Load the RHS and LHS operands.
524   // __block variables need to have the rhs evaluated first, plus this should
525   // improve codegen a little.
526   OpInfo.Ty = E->getComputationResultType();
527 
528   // The RHS should have been converted to the computation type.
529   assert(OpInfo.Ty->isAnyComplexType());
530   assert(CGF.getContext().hasSameUnqualifiedType(OpInfo.Ty,
531                                                  E->getRHS()->getType()));
532   OpInfo.RHS = Visit(E->getRHS());
533 
534   LValue LHS = CGF.EmitLValue(E->getLHS());
535   // We know the LHS is a complex lvalue.
536   ComplexPairTy LHSComplexPair;
537   if (LHS.isPropertyRef())
538     LHSComplexPair =
539       CGF.EmitObjCPropertyGet(LHS.getPropertyRefExpr()).getComplexVal();
540   else if (LHS.isKVCRef())
541     LHSComplexPair =
542       CGF.EmitObjCPropertyGet(LHS.getKVCRefExpr()).getComplexVal();
543   else
544     LHSComplexPair = EmitLoadOfComplex(LHS.getAddress(),
545                                        LHS.isVolatileQualified());
546 
547   OpInfo.LHS = EmitComplexToComplexCast(LHSComplexPair, LHSTy, OpInfo.Ty);
548 
549   // Expand the binary operator.
550   ComplexPairTy Result = (this->*Func)(OpInfo);
551 
552   // Truncate the result back to the LHS type.
553   Result = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
554   Val = Result;
555 
556   // Store the result value into the LHS lvalue.
557   if (LHS.isPropertyRef())
558     CGF.EmitObjCPropertySet(LHS.getPropertyRefExpr(),
559                             RValue::getComplex(Result));
560   else if (LHS.isKVCRef())
561     CGF.EmitObjCPropertySet(LHS.getKVCRefExpr(), RValue::getComplex(Result));
562   else
563     EmitStoreOfComplex(Result, LHS.getAddress(), LHS.isVolatileQualified());
564 
565   return LHS;
566 }
567 
568 // Compound assignments.
569 ComplexPairTy ComplexExprEmitter::
570 EmitCompoundAssign(const CompoundAssignOperator *E,
571                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
572   ComplexPairTy Val;
573   LValue LV = EmitCompoundAssignLValue(E, Func, Val);
574 
575   // The result of an assignment in C is the assigned r-value.
576   if (!CGF.getContext().getLangOptions().CPlusPlus)
577     return Val;
578 
579   // Objective-C property assignment never reloads the value following a store.
580   if (LV.isPropertyRef() || LV.isKVCRef())
581     return Val;
582 
583   // If the lvalue is non-volatile, return the computed value of the assignment.
584   if (!LV.isVolatileQualified())
585     return Val;
586 
587   return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
588 }
589 
590 LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
591                                                ComplexPairTy &Val) {
592   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
593                                                  E->getRHS()->getType()) &&
594          "Invalid assignment");
595   TestAndClearIgnoreReal();
596   TestAndClearIgnoreImag();
597 
598   // Emit the RHS.
599   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   return LHS;
613 }
614 
615 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
616   ComplexPairTy Val;
617   LValue LV = EmitBinAssignLValue(E, Val);
618 
619   // The result of an assignment in C is the assigned r-value.
620   if (!CGF.getContext().getLangOptions().CPlusPlus)
621     return Val;
622 
623   // Objective-C property assignment never reloads the value following a store.
624   if (LV.isPropertyRef() || LV.isKVCRef())
625     return Val;
626 
627   // If the lvalue is non-volatile, return the computed value of the assignment.
628   if (!LV.isVolatileQualified())
629     return Val;
630 
631   return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
632 }
633 
634 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
635   CGF.EmitStmt(E->getLHS());
636   CGF.EnsureInsertPoint();
637   return Visit(E->getRHS());
638 }
639 
640 ComplexPairTy ComplexExprEmitter::
641 VisitConditionalOperator(const ConditionalOperator *E) {
642   TestAndClearIgnoreReal();
643   TestAndClearIgnoreImag();
644   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
645   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
646   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
647 
648   if (E->getLHS())
649     CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
650   else {
651     Expr *save = E->getSAVE();
652     assert(save && "VisitConditionalOperator - save is null");
653     // Intentianlly not doing direct assignment to ConditionalSaveExprs[save] !!
654     ComplexPairTy SaveVal = Visit(save);
655     CGF.ConditionalSaveComplexExprs[save] = SaveVal;
656     CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
657   }
658 
659   CGF.EmitBlock(LHSBlock);
660   ComplexPairTy LHS = Visit(E->getTrueExpr());
661   LHSBlock = Builder.GetInsertBlock();
662   CGF.EmitBranch(ContBlock);
663 
664   CGF.EmitBlock(RHSBlock);
665 
666   ComplexPairTy RHS = Visit(E->getRHS());
667   RHSBlock = Builder.GetInsertBlock();
668   CGF.EmitBranch(ContBlock);
669 
670   CGF.EmitBlock(ContBlock);
671 
672   // Create a PHI node for the real part.
673   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), "cond.r");
674   RealPN->reserveOperandSpace(2);
675   RealPN->addIncoming(LHS.first, LHSBlock);
676   RealPN->addIncoming(RHS.first, RHSBlock);
677 
678   // Create a PHI node for the imaginary part.
679   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), "cond.i");
680   ImagPN->reserveOperandSpace(2);
681   ImagPN->addIncoming(LHS.second, LHSBlock);
682   ImagPN->addIncoming(RHS.second, RHSBlock);
683 
684   return ComplexPairTy(RealPN, ImagPN);
685 }
686 
687 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
688   return Visit(E->getChosenSubExpr(CGF.getContext()));
689 }
690 
691 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
692     bool Ignore = TestAndClearIgnoreReal();
693     (void)Ignore;
694     assert (Ignore == false && "init list ignored");
695     Ignore = TestAndClearIgnoreImag();
696     (void)Ignore;
697     assert (Ignore == false && "init list ignored");
698   if (E->getNumInits())
699     return Visit(E->getInit(0));
700 
701   // Empty init list intializes to null
702   QualType Ty = E->getType()->getAs<ComplexType>()->getElementType();
703   const llvm::Type* LTy = CGF.ConvertType(Ty);
704   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
705   return ComplexPairTy(zeroConstant, zeroConstant);
706 }
707 
708 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
709   llvm::Value *ArgValue = CGF.EmitVAListRef(E->getSubExpr());
710   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, E->getType());
711 
712   if (!ArgPtr) {
713     CGF.ErrorUnsupported(E, "complex va_arg expression");
714     const llvm::Type *EltTy =
715       CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
716     llvm::Value *U = llvm::UndefValue::get(EltTy);
717     return ComplexPairTy(U, U);
718   }
719 
720   // FIXME Volatility.
721   return EmitLoadOfComplex(ArgPtr, false);
722 }
723 
724 //===----------------------------------------------------------------------===//
725 //                         Entry Point into this File
726 //===----------------------------------------------------------------------===//
727 
728 /// EmitComplexExpr - Emit the computation of the specified expression of
729 /// complex type, ignoring the result.
730 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
731                                                bool IgnoreImag) {
732   assert(E && E->getType()->isAnyComplexType() &&
733          "Invalid complex expression to emit");
734 
735   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag)
736     .Visit(const_cast<Expr*>(E));
737 }
738 
739 /// EmitComplexExprIntoAddr - Emit the computation of the specified expression
740 /// of complex type, storing into the specified Value*.
741 void CodeGenFunction::EmitComplexExprIntoAddr(const Expr *E,
742                                               llvm::Value *DestAddr,
743                                               bool DestIsVolatile) {
744   assert(E && E->getType()->isAnyComplexType() &&
745          "Invalid complex expression to emit");
746   ComplexExprEmitter Emitter(*this);
747   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
748   Emitter.EmitStoreOfComplex(Val, DestAddr, DestIsVolatile);
749 }
750 
751 /// StoreComplexToAddr - Store a complex number into the specified address.
752 void CodeGenFunction::StoreComplexToAddr(ComplexPairTy V,
753                                          llvm::Value *DestAddr,
754                                          bool DestIsVolatile) {
755   ComplexExprEmitter(*this).EmitStoreOfComplex(V, DestAddr, DestIsVolatile);
756 }
757 
758 /// LoadComplexFromAddr - Load a complex number from the specified address.
759 ComplexPairTy CodeGenFunction::LoadComplexFromAddr(llvm::Value *SrcAddr,
760                                                    bool SrcIsVolatile) {
761   return ComplexExprEmitter(*this).EmitLoadOfComplex(SrcAddr, SrcIsVolatile);
762 }
763