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 #include "llvm/Support/Compiler.h"
22 using namespace clang;
23 using namespace CodeGen;
24 
25 //===----------------------------------------------------------------------===//
26 //                        Complex Expression Emitter
27 //===----------------------------------------------------------------------===//
28 
29 typedef CodeGenFunction::ComplexPairTy ComplexPairTy;
30 
31 namespace  {
32 class VISIBILITY_HIDDEN ComplexExprEmitter
33   : public StmtVisitor<ComplexExprEmitter, ComplexPairTy> {
34   CodeGenFunction &CGF;
35   CGBuilderTy &Builder;
36   // True is we should ignore the value of a
37   bool IgnoreReal;
38   bool IgnoreImag;
39   // True if we should ignore the value of a=b
40   bool IgnoreRealAssign;
41   bool IgnoreImagAssign;
42 public:
43   ComplexExprEmitter(CodeGenFunction &cgf, bool ir=false, bool ii=false,
44                      bool irn=false, bool iin=false)
45     : CGF(cgf), Builder(CGF.Builder), IgnoreReal(ir), IgnoreImag(ii),
46     IgnoreRealAssign(irn), IgnoreImagAssign(iin) {
47   }
48 
49 
50   //===--------------------------------------------------------------------===//
51   //                               Utilities
52   //===--------------------------------------------------------------------===//
53 
54   bool TestAndClearIgnoreReal() {
55     bool I = IgnoreReal;
56     IgnoreReal = false;
57     return I;
58   }
59   bool TestAndClearIgnoreImag() {
60     bool I = IgnoreImag;
61     IgnoreImag = false;
62     return I;
63   }
64   bool TestAndClearIgnoreRealAssign() {
65     bool I = IgnoreRealAssign;
66     IgnoreRealAssign = false;
67     return I;
68   }
69   bool TestAndClearIgnoreImagAssign() {
70     bool I = IgnoreImagAssign;
71     IgnoreImagAssign = false;
72     return I;
73   }
74 
75   /// EmitLoadOfLValue - Given an expression with complex type that represents a
76   /// value l-value, this method emits the address of the l-value, then loads
77   /// and returns the result.
78   ComplexPairTy EmitLoadOfLValue(const Expr *E) {
79     LValue LV = CGF.EmitLValue(E);
80     if (LV.isSimple())
81       return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
82 
83     if (LV.isPropertyRef())
84       return CGF.EmitObjCPropertyGet(LV.getPropertyRefExpr()).getComplexVal();
85 
86     assert(LV.isKVCRef() && "Unknown LValue type!");
87     return CGF.EmitObjCPropertyGet(LV.getKVCRefExpr()).getComplexVal();
88   }
89 
90   /// EmitLoadOfComplex - Given a pointer to a complex value, emit code to load
91   /// the real and imaginary pieces.
92   ComplexPairTy EmitLoadOfComplex(llvm::Value *SrcPtr, bool isVolatile);
93 
94   /// EmitStoreOfComplex - Store the specified real/imag parts into the
95   /// specified value pointer.
96   void EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *ResPtr, bool isVol);
97 
98   /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
99   ComplexPairTy EmitComplexToComplexCast(ComplexPairTy Val, QualType SrcType,
100                                          QualType DestType);
101 
102   //===--------------------------------------------------------------------===//
103   //                            Visitor Methods
104   //===--------------------------------------------------------------------===//
105 
106   ComplexPairTy VisitStmt(Stmt *S) {
107     S->dump(CGF.getContext().getSourceManager());
108     assert(0 && "Stmt can't have complex result type!");
109     return ComplexPairTy();
110   }
111   ComplexPairTy VisitExpr(Expr *S);
112   ComplexPairTy VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr());}
113   ComplexPairTy VisitImaginaryLiteral(const ImaginaryLiteral *IL);
114 
115   // l-values.
116   ComplexPairTy VisitDeclRefExpr(const Expr *E) { return EmitLoadOfLValue(E); }
117   ComplexPairTy VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
118     return EmitLoadOfLValue(E);
119   }
120   ComplexPairTy VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
121     return EmitLoadOfLValue(E);
122   }
123   ComplexPairTy VisitObjCImplctSetterGetterRefExpr(
124                                ObjCImplctSetterGetterRefExpr *E) {
125     return EmitLoadOfLValue(E);
126   }
127   ComplexPairTy VisitObjCMessageExpr(ObjCMessageExpr *E) {
128     return CGF.EmitObjCMessageExpr(E).getComplexVal();
129   }
130   ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
131   ComplexPairTy VisitMemberExpr(const Expr *E) { return EmitLoadOfLValue(E); }
132 
133   // FIXME: CompoundLiteralExpr
134 
135   ComplexPairTy EmitCast(Expr *Op, QualType DestTy);
136   ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
137     // Unlike for scalars, we don't have to worry about function->ptr demotion
138     // here.
139     return EmitCast(E->getSubExpr(), E->getType());
140   }
141   ComplexPairTy VisitCastExpr(CastExpr *E) {
142     return EmitCast(E->getSubExpr(), E->getType());
143   }
144   ComplexPairTy VisitCallExpr(const CallExpr *E);
145   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
146 
147   // Operators.
148   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
149                                    bool isInc, bool isPre);
150   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
151     return VisitPrePostIncDec(E, false, false);
152   }
153   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
154     return VisitPrePostIncDec(E, true, false);
155   }
156   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
157     return VisitPrePostIncDec(E, false, true);
158   }
159   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
160     return VisitPrePostIncDec(E, true, true);
161   }
162   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
163   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
164     TestAndClearIgnoreReal();
165     TestAndClearIgnoreImag();
166     TestAndClearIgnoreRealAssign();
167     TestAndClearIgnoreImagAssign();
168     return Visit(E->getSubExpr());
169   }
170   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
171   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
172   // LNot,Real,Imag never return complex.
173   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
174     return Visit(E->getSubExpr());
175   }
176   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
177     return Visit(DAE->getExpr());
178   }
179   ComplexPairTy VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) {
180     return CGF.EmitCXXExprWithTemporaries(E).getComplexVal();
181   }
182   ComplexPairTy VisitCXXZeroInitValueExpr(CXXZeroInitValueExpr *E) {
183     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
184     QualType Elem = E->getType()->getAsComplexType()->getElementType();
185     llvm::Constant *Null =
186                        llvm::Constant::getNullValue(CGF.ConvertType(Elem));
187     return ComplexPairTy(Null, Null);
188   }
189   ComplexPairTy VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
190     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
191     QualType Elem = E->getType()->getAsComplexType()->getElementType();
192     llvm::Constant *Null =
193                        llvm::Constant::getNullValue(CGF.ConvertType(Elem));
194     return ComplexPairTy(Null, Null);
195   }
196 
197   struct BinOpInfo {
198     ComplexPairTy LHS;
199     ComplexPairTy RHS;
200     QualType Ty;  // Computation Type.
201   };
202 
203   BinOpInfo EmitBinOps(const BinaryOperator *E);
204   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
205                                    ComplexPairTy (ComplexExprEmitter::*Func)
206                                    (const BinOpInfo &));
207 
208   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
209   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
210   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
211   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
212 
213   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
214     return EmitBinMul(EmitBinOps(E));
215   }
216   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
217     return EmitBinAdd(EmitBinOps(E));
218   }
219   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
220     return EmitBinSub(EmitBinOps(E));
221   }
222   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
223     return EmitBinDiv(EmitBinOps(E));
224   }
225 
226   // Compound assignments.
227   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
228     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
229   }
230   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
231     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
232   }
233   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
234     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
235   }
236   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
237     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
238   }
239 
240   // GCC rejects rem/and/or/xor for integer complex.
241   // Logical and/or always return int, never complex.
242 
243   // No comparisons produce a complex result.
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::SmallString<64> Name(SrcPtr->getName().begin(),
266                              SrcPtr->getName().end());
267 
268   llvm::Value *Real=0, *Imag=0;
269 
270   if (!IgnoreReal) {
271     // FIXME: Clean this up once builder takes Twine/StringRef.
272     Name += ".realp";
273     llvm::Value *RealPtr = Builder.CreateStructGEP(SrcPtr, 0,
274                                                    Name.str().str().c_str());
275 
276     Name.pop_back();  // .realp -> .real
277     // FIXME: Clean this up once builder takes Twine/StringRef.
278     Real = Builder.CreateLoad(RealPtr, isVolatile,
279                               Name.str().str().c_str());
280     Name.resize(Name.size()-4); // .real -> .imagp
281   }
282 
283   if (!IgnoreImag) {
284     Name += "imagp";
285 
286     // FIXME: Clean this up once builder takes Twine/StringRef.
287     llvm::Value *ImagPtr = Builder.CreateStructGEP(SrcPtr, 1,
288                                                    Name.str().str().c_str());
289 
290     Name.pop_back();  // .imagp -> .imag
291     // FIXME: Clean this up once builder takes Twine/StringRef.
292     Imag = Builder.CreateLoad(ImagPtr, isVolatile, Name.str().str().c_str());
293   }
294   return ComplexPairTy(Real, Imag);
295 }
296 
297 /// EmitStoreOfComplex - Store the specified real/imag parts into the
298 /// specified value pointer.
299 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *Ptr,
300                                             bool isVolatile) {
301   llvm::Value *RealPtr = Builder.CreateStructGEP(Ptr, 0, "real");
302   llvm::Value *ImagPtr = Builder.CreateStructGEP(Ptr, 1, "imag");
303 
304   Builder.CreateStore(Val.first, RealPtr, isVolatile);
305   Builder.CreateStore(Val.second, ImagPtr, isVolatile);
306 }
307 
308 
309 
310 //===----------------------------------------------------------------------===//
311 //                            Visitor Methods
312 //===----------------------------------------------------------------------===//
313 
314 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
315   CGF.ErrorUnsupported(E, "complex expression");
316   const llvm::Type *EltTy =
317     CGF.ConvertType(E->getType()->getAsComplexType()->getElementType());
318   llvm::Value *U = llvm::UndefValue::get(EltTy);
319   return ComplexPairTy(U, U);
320 }
321 
322 ComplexPairTy ComplexExprEmitter::
323 VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
324   llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
325   return
326         ComplexPairTy(llvm::Constant::getNullValue(Imag->getType()), Imag);
327 }
328 
329 
330 ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
331   if (E->getCallReturnType()->isReferenceType())
332     return EmitLoadOfLValue(E);
333 
334   return CGF.EmitCallExpr(E).getComplexVal();
335 }
336 
337 ComplexPairTy ComplexExprEmitter::VisitStmtExpr(const StmtExpr *E) {
338   return CGF.EmitCompoundStmt(*E->getSubStmt(), true).getComplexVal();
339 }
340 
341 /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
342 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
343                                                            QualType SrcType,
344                                                            QualType DestType) {
345   // Get the src/dest element type.
346   SrcType = SrcType->getAsComplexType()->getElementType();
347   DestType = DestType->getAsComplexType()->getElementType();
348 
349   // C99 6.3.1.6: When a value of complex type is converted to another
350   // complex type, both the real and imaginary parts follow the conversion
351   // rules for the corresponding real types.
352   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType);
353   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType);
354   return Val;
355 }
356 
357 ComplexPairTy ComplexExprEmitter::EmitCast(Expr *Op, QualType DestTy) {
358   // Two cases here: cast from (complex to complex) and (scalar to complex).
359   if (Op->getType()->isAnyComplexType())
360     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
361 
362   // C99 6.3.1.7: When a value of real type is converted to a complex type, the
363   // real part of the complex result value is determined by the rules of
364   // conversion to the corresponding real type and the imaginary part of the
365   // complex result value is a positive zero or an unsigned zero.
366   llvm::Value *Elt = CGF.EmitScalarExpr(Op);
367 
368   // Convert the input element to the element type of the complex.
369   DestTy = DestTy->getAsComplexType()->getElementType();
370   Elt = CGF.EmitScalarConversion(Elt, Op->getType(), DestTy);
371 
372   // Return (realval, 0).
373   return ComplexPairTy(Elt, llvm::Constant::getNullValue(Elt->getType()));
374 }
375 
376 ComplexPairTy ComplexExprEmitter::VisitPrePostIncDec(const UnaryOperator *E,
377                                                      bool isInc, bool isPre) {
378   LValue LV = CGF.EmitLValue(E->getSubExpr());
379   ComplexPairTy InVal = EmitLoadOfComplex(LV.getAddress(),
380                                           LV.isVolatileQualified());
381 
382   llvm::Value *NextVal;
383   if (isa<llvm::IntegerType>(InVal.first->getType())) {
384     uint64_t AmountVal = isInc ? 1 : -1;
385     NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
386 
387     // Add the inc/dec to the real part.
388     NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
389   } else {
390     QualType ElemTy = E->getType()->getAsComplexType()->getElementType();
391     llvm::APFloat FVal(CGF.getContext().getFloatTypeSemantics(ElemTy), 1);
392     if (!isInc)
393       FVal.changeSign();
394     NextVal = llvm::ConstantFP::get(CGF.getLLVMContext(), FVal);
395 
396     // Add the inc/dec to the real part.
397     NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
398   }
399 
400   ComplexPairTy IncVal(NextVal, InVal.second);
401 
402   // Store the updated result through the lvalue.
403   EmitStoreOfComplex(IncVal, LV.getAddress(), LV.isVolatileQualified());
404 
405   // If this is a postinc, return the value read from memory, otherwise use the
406   // updated value.
407   return isPre ? IncVal : InVal;
408 }
409 
410 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
411   TestAndClearIgnoreReal();
412   TestAndClearIgnoreImag();
413   TestAndClearIgnoreRealAssign();
414   TestAndClearIgnoreImagAssign();
415   ComplexPairTy Op = Visit(E->getSubExpr());
416 
417   llvm::Value *ResR, *ResI;
418   if (Op.first->getType()->isFloatingPoint()) {
419     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
420     ResI = Builder.CreateFNeg(Op.second, "neg.i");
421   } else {
422     ResR = Builder.CreateNeg(Op.first,  "neg.r");
423     ResI = Builder.CreateNeg(Op.second, "neg.i");
424   }
425   return ComplexPairTy(ResR, ResI);
426 }
427 
428 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
429   TestAndClearIgnoreReal();
430   TestAndClearIgnoreImag();
431   TestAndClearIgnoreRealAssign();
432   TestAndClearIgnoreImagAssign();
433   // ~(a+ib) = a + i*-b
434   ComplexPairTy Op = Visit(E->getSubExpr());
435   llvm::Value *ResI;
436   if (Op.second->getType()->isFloatingPoint())
437     ResI = Builder.CreateFNeg(Op.second, "conj.i");
438   else
439     ResI = Builder.CreateNeg(Op.second, "conj.i");
440 
441   return ComplexPairTy(Op.first, ResI);
442 }
443 
444 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
445   llvm::Value *ResR, *ResI;
446 
447   if (Op.LHS.first->getType()->isFloatingPoint()) {
448     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
449     ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
450   } else {
451     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
452     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
453   }
454   return ComplexPairTy(ResR, ResI);
455 }
456 
457 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
458   llvm::Value *ResR, *ResI;
459   if (Op.LHS.first->getType()->isFloatingPoint()) {
460     ResR = Builder.CreateFSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
461     ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
462   } else {
463     ResR = Builder.CreateSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
464     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
465   }
466   return ComplexPairTy(ResR, ResI);
467 }
468 
469 
470 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
471   using llvm::Value;
472   Value *ResR, *ResI;
473 
474   if (Op.LHS.first->getType()->isFloatingPoint()) {
475     Value *ResRl = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
476     Value *ResRr = Builder.CreateFMul(Op.LHS.second, Op.RHS.second,"mul.rr");
477     ResR  = Builder.CreateFSub(ResRl, ResRr, "mul.r");
478 
479     Value *ResIl = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il");
480     Value *ResIr = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
481     ResI  = Builder.CreateFAdd(ResIl, ResIr, "mul.i");
482   } else {
483     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
484     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
485     ResR  = Builder.CreateSub(ResRl, ResRr, "mul.r");
486 
487     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
488     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
489     ResI  = Builder.CreateAdd(ResIl, ResIr, "mul.i");
490   }
491   return ComplexPairTy(ResR, ResI);
492 }
493 
494 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
495   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
496   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
497 
498 
499   llvm::Value *DSTr, *DSTi;
500   if (Op.LHS.first->getType()->isFloatingPoint()) {
501     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
502     llvm::Value *Tmp1 = Builder.CreateFMul(LHSr, RHSr, "tmp"); // a*c
503     llvm::Value *Tmp2 = Builder.CreateFMul(LHSi, RHSi, "tmp"); // b*d
504     llvm::Value *Tmp3 = Builder.CreateFAdd(Tmp1, Tmp2, "tmp"); // ac+bd
505 
506     llvm::Value *Tmp4 = Builder.CreateFMul(RHSr, RHSr, "tmp"); // c*c
507     llvm::Value *Tmp5 = Builder.CreateFMul(RHSi, RHSi, "tmp"); // d*d
508     llvm::Value *Tmp6 = Builder.CreateFAdd(Tmp4, Tmp5, "tmp"); // cc+dd
509 
510     llvm::Value *Tmp7 = Builder.CreateFMul(LHSi, RHSr, "tmp"); // b*c
511     llvm::Value *Tmp8 = Builder.CreateFMul(LHSr, RHSi, "tmp"); // a*d
512     llvm::Value *Tmp9 = Builder.CreateFSub(Tmp7, Tmp8, "tmp"); // bc-ad
513 
514     DSTr = Builder.CreateFDiv(Tmp3, Tmp6, "tmp");
515     DSTi = Builder.CreateFDiv(Tmp9, Tmp6, "tmp");
516   } else {
517     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
518     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr, "tmp"); // a*c
519     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi, "tmp"); // b*d
520     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2, "tmp"); // ac+bd
521 
522     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr, "tmp"); // c*c
523     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi, "tmp"); // d*d
524     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5, "tmp"); // cc+dd
525 
526     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr, "tmp"); // b*c
527     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi, "tmp"); // a*d
528     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8, "tmp"); // bc-ad
529 
530     if (Op.Ty->getAsComplexType()->getElementType()->isUnsignedIntegerType()) {
531       DSTr = Builder.CreateUDiv(Tmp3, Tmp6, "tmp");
532       DSTi = Builder.CreateUDiv(Tmp9, Tmp6, "tmp");
533     } else {
534       DSTr = Builder.CreateSDiv(Tmp3, Tmp6, "tmp");
535       DSTi = Builder.CreateSDiv(Tmp9, Tmp6, "tmp");
536     }
537   }
538 
539   return ComplexPairTy(DSTr, DSTi);
540 }
541 
542 ComplexExprEmitter::BinOpInfo
543 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
544   TestAndClearIgnoreReal();
545   TestAndClearIgnoreImag();
546   TestAndClearIgnoreRealAssign();
547   TestAndClearIgnoreImagAssign();
548   BinOpInfo Ops;
549   Ops.LHS = Visit(E->getLHS());
550   Ops.RHS = Visit(E->getRHS());
551   Ops.Ty = E->getType();
552   return Ops;
553 }
554 
555 
556 // Compound assignments.
557 ComplexPairTy ComplexExprEmitter::
558 EmitCompoundAssign(const CompoundAssignOperator *E,
559                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
560   TestAndClearIgnoreReal();
561   TestAndClearIgnoreImag();
562   bool ignreal = TestAndClearIgnoreRealAssign();
563   bool ignimag = TestAndClearIgnoreImagAssign();
564   QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType();
565 
566   BinOpInfo OpInfo;
567 
568   // Load the RHS and LHS operands.
569   // __block variables need to have the rhs evaluated first, plus this should
570   // improve codegen a little.  It is possible for the RHS to be complex or
571   // scalar.
572   OpInfo.Ty = E->getComputationResultType();
573   OpInfo.RHS = EmitCast(E->getRHS(), OpInfo.Ty);
574 
575   LValue LHSLV = CGF.EmitLValue(E->getLHS());
576 
577 
578   // We know the LHS is a complex lvalue.
579   OpInfo.LHS=EmitLoadOfComplex(LHSLV.getAddress(),LHSLV.isVolatileQualified());
580   OpInfo.LHS=EmitComplexToComplexCast(OpInfo.LHS, LHSTy, OpInfo.Ty);
581 
582   // Expand the binary operator.
583   ComplexPairTy Result = (this->*Func)(OpInfo);
584 
585   // Truncate the result back to the LHS type.
586   Result = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
587 
588   // Store the result value into the LHS lvalue.
589   EmitStoreOfComplex(Result, LHSLV.getAddress(), LHSLV.isVolatileQualified());
590   // And now return the LHS
591   IgnoreReal = ignreal;
592   IgnoreImag = ignimag;
593   IgnoreRealAssign = ignreal;
594   IgnoreImagAssign = ignimag;
595   return EmitLoadOfComplex(LHSLV.getAddress(), LHSLV.isVolatileQualified());
596 }
597 
598 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
599   TestAndClearIgnoreReal();
600   TestAndClearIgnoreImag();
601   bool ignreal = TestAndClearIgnoreRealAssign();
602   bool ignimag = TestAndClearIgnoreImagAssign();
603   assert(CGF.getContext().getCanonicalType(E->getLHS()->getType()) ==
604          CGF.getContext().getCanonicalType(E->getRHS()->getType()) &&
605          "Invalid assignment");
606   // Emit the RHS.
607   ComplexPairTy Val = Visit(E->getRHS());
608 
609   // Compute the address to store into.
610   LValue LHS = CGF.EmitLValue(E->getLHS());
611 
612   // Store into it, if simple.
613   if (LHS.isSimple()) {
614     EmitStoreOfComplex(Val, LHS.getAddress(), LHS.isVolatileQualified());
615 
616     // And now return the LHS
617     IgnoreReal = ignreal;
618     IgnoreImag = ignimag;
619     IgnoreRealAssign = ignreal;
620     IgnoreImagAssign = ignimag;
621     return EmitLoadOfComplex(LHS.getAddress(), LHS.isVolatileQualified());
622   }
623 
624   // Otherwise we must have a property setter (no complex vector/bitfields).
625   if (LHS.isPropertyRef())
626     CGF.EmitObjCPropertySet(LHS.getPropertyRefExpr(), RValue::getComplex(Val));
627   else
628     CGF.EmitObjCPropertySet(LHS.getKVCRefExpr(), RValue::getComplex(Val));
629 
630   // There is no reload after a store through a method, but we need to restore
631   // the Ignore* flags.
632   IgnoreReal = ignreal;
633   IgnoreImag = ignimag;
634   IgnoreRealAssign = ignreal;
635   IgnoreImagAssign = ignimag;
636   return Val;
637 }
638 
639 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
640   CGF.EmitStmt(E->getLHS());
641   CGF.EnsureInsertPoint();
642   return Visit(E->getRHS());
643 }
644 
645 ComplexPairTy ComplexExprEmitter::
646 VisitConditionalOperator(const ConditionalOperator *E) {
647   TestAndClearIgnoreReal();
648   TestAndClearIgnoreImag();
649   TestAndClearIgnoreRealAssign();
650   TestAndClearIgnoreImagAssign();
651   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
652   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
653   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
654 
655   llvm::Value *Cond = CGF.EvaluateExprAsBool(E->getCond());
656   Builder.CreateCondBr(Cond, LHSBlock, RHSBlock);
657 
658   CGF.EmitBlock(LHSBlock);
659 
660   // Handle the GNU extension for missing LHS.
661   assert(E->getLHS() && "Must have LHS for complex value");
662 
663   ComplexPairTy LHS = Visit(E->getLHS());
664   LHSBlock = Builder.GetInsertBlock();
665   CGF.EmitBranch(ContBlock);
666 
667   CGF.EmitBlock(RHSBlock);
668 
669   ComplexPairTy RHS = Visit(E->getRHS());
670   RHSBlock = Builder.GetInsertBlock();
671   CGF.EmitBranch(ContBlock);
672 
673   CGF.EmitBlock(ContBlock);
674 
675   // Create a PHI node for the real part.
676   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), "cond.r");
677   RealPN->reserveOperandSpace(2);
678   RealPN->addIncoming(LHS.first, LHSBlock);
679   RealPN->addIncoming(RHS.first, RHSBlock);
680 
681   // Create a PHI node for the imaginary part.
682   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), "cond.i");
683   ImagPN->reserveOperandSpace(2);
684   ImagPN->addIncoming(LHS.second, LHSBlock);
685   ImagPN->addIncoming(RHS.second, RHSBlock);
686 
687   return ComplexPairTy(RealPN, ImagPN);
688 }
689 
690 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
691   return Visit(E->getChosenSubExpr(CGF.getContext()));
692 }
693 
694 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
695     bool Ignore = TestAndClearIgnoreReal();
696     (void)Ignore;
697     assert (Ignore == false && "init list ignored");
698     Ignore = TestAndClearIgnoreImag();
699     (void)Ignore;
700     assert (Ignore == false && "init list ignored");
701   if (E->getNumInits())
702     return Visit(E->getInit(0));
703 
704   // Empty init list intializes to null
705   QualType Ty = E->getType()->getAsComplexType()->getElementType();
706   const llvm::Type* LTy = CGF.ConvertType(Ty);
707   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
708   return ComplexPairTy(zeroConstant, zeroConstant);
709 }
710 
711 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
712   llvm::Value *ArgValue = CGF.EmitVAListRef(E->getSubExpr());
713   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, E->getType());
714 
715   if (!ArgPtr) {
716     CGF.ErrorUnsupported(E, "complex va_arg expression");
717     const llvm::Type *EltTy =
718       CGF.ConvertType(E->getType()->getAsComplexType()->getElementType());
719     llvm::Value *U = llvm::UndefValue::get(EltTy);
720     return ComplexPairTy(U, U);
721   }
722 
723   // FIXME Volatility.
724   return EmitLoadOfComplex(ArgPtr, false);
725 }
726 
727 //===----------------------------------------------------------------------===//
728 //                         Entry Point into this File
729 //===----------------------------------------------------------------------===//
730 
731 /// EmitComplexExpr - Emit the computation of the specified expression of
732 /// complex type, ignoring the result.
733 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
734                                                bool IgnoreImag, bool IgnoreRealAssign, bool IgnoreImagAssign) {
735   assert(E && E->getType()->isAnyComplexType() &&
736          "Invalid complex expression to emit");
737 
738   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag, IgnoreRealAssign,
739                             IgnoreImagAssign)
740     .Visit(const_cast<Expr*>(E));
741 }
742 
743 /// EmitComplexExprIntoAddr - Emit the computation of the specified expression
744 /// of complex type, storing into the specified Value*.
745 void CodeGenFunction::EmitComplexExprIntoAddr(const Expr *E,
746                                               llvm::Value *DestAddr,
747                                               bool DestIsVolatile) {
748   assert(E && E->getType()->isAnyComplexType() &&
749          "Invalid complex expression to emit");
750   ComplexExprEmitter Emitter(*this);
751   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
752   Emitter.EmitStoreOfComplex(Val, DestAddr, DestIsVolatile);
753 }
754 
755 /// StoreComplexToAddr - Store a complex number into the specified address.
756 void CodeGenFunction::StoreComplexToAddr(ComplexPairTy V,
757                                          llvm::Value *DestAddr,
758                                          bool DestIsVolatile) {
759   ComplexExprEmitter(*this).EmitStoreOfComplex(V, DestAddr, DestIsVolatile);
760 }
761 
762 /// LoadComplexFromAddr - Load a complex number from the specified address.
763 ComplexPairTy CodeGenFunction::LoadComplexFromAddr(llvm::Value *SrcAddr,
764                                                    bool SrcIsVolatile) {
765   return ComplexExprEmitter(*this).EmitLoadOfComplex(SrcAddr, SrcIsVolatile);
766 }
767