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 VisitObjCKVCRefExpr(ObjCKVCRefExpr *E) {
124     return EmitLoadOfLValue(E);
125   }
126   ComplexPairTy VisitObjCMessageExpr(ObjCMessageExpr *E) {
127     return CGF.EmitObjCMessageExpr(E).getComplexVal();
128   }
129   ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
130   ComplexPairTy VisitMemberExpr(const Expr *E) { return EmitLoadOfLValue(E); }
131 
132   // FIXME: CompoundLiteralExpr
133 
134   ComplexPairTy EmitCast(Expr *Op, QualType DestTy);
135   ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
136     // Unlike for scalars, we don't have to worry about function->ptr demotion
137     // here.
138     return EmitCast(E->getSubExpr(), E->getType());
139   }
140   ComplexPairTy VisitCastExpr(CastExpr *E) {
141     return EmitCast(E->getSubExpr(), E->getType());
142   }
143   ComplexPairTy VisitCallExpr(const CallExpr *E);
144   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
145 
146   // Operators.
147   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
148                                    bool isInc, bool isPre);
149   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
150     return VisitPrePostIncDec(E, false, false);
151   }
152   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
153     return VisitPrePostIncDec(E, true, false);
154   }
155   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
156     return VisitPrePostIncDec(E, false, true);
157   }
158   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
159     return VisitPrePostIncDec(E, true, true);
160   }
161   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
162   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
163     TestAndClearIgnoreReal();
164     TestAndClearIgnoreImag();
165     TestAndClearIgnoreRealAssign();
166     TestAndClearIgnoreImagAssign();
167     return Visit(E->getSubExpr());
168   }
169   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
170   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
171   // LNot,Real,Imag never return complex.
172   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
173     return Visit(E->getSubExpr());
174   }
175   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
176     return Visit(DAE->getExpr());
177   }
178   ComplexPairTy VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) {
179     return CGF.EmitCXXExprWithTemporaries(E).getComplexVal();
180   }
181   ComplexPairTy VisitCXXZeroInitValueExpr(CXXZeroInitValueExpr *E) {
182     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
183     QualType Elem = E->getType()->getAsComplexType()->getElementType();
184     llvm::Constant *Null =
185                        CGF.getLLVMContext().getNullValue(CGF.ConvertType(Elem));
186     return ComplexPairTy(Null, Null);
187   }
188   ComplexPairTy VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
189     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
190     QualType Elem = E->getType()->getAsComplexType()->getElementType();
191     llvm::Constant *Null =
192                        CGF.getLLVMContext().getNullValue(CGF.ConvertType(Elem));
193     return ComplexPairTy(Null, Null);
194   }
195 
196   struct BinOpInfo {
197     ComplexPairTy LHS;
198     ComplexPairTy RHS;
199     QualType Ty;  // Computation Type.
200   };
201 
202   BinOpInfo EmitBinOps(const BinaryOperator *E);
203   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
204                                    ComplexPairTy (ComplexExprEmitter::*Func)
205                                    (const BinOpInfo &));
206 
207   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
208   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
209   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
210   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
211 
212   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
213     return EmitBinMul(EmitBinOps(E));
214   }
215   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
216     return EmitBinAdd(EmitBinOps(E));
217   }
218   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
219     return EmitBinSub(EmitBinOps(E));
220   }
221   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
222     return EmitBinDiv(EmitBinOps(E));
223   }
224 
225   // Compound assignments.
226   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
227     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
228   }
229   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
230     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
231   }
232   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
233     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
234   }
235   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
236     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
237   }
238 
239   // GCC rejects rem/and/or/xor for integer complex.
240   // Logical and/or always return int, never complex.
241 
242   // No comparisons produce a complex result.
243   ComplexPairTy VisitBinAssign     (const BinaryOperator *E);
244   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
245 
246 
247   ComplexPairTy VisitConditionalOperator(const ConditionalOperator *CO);
248   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
249 
250   ComplexPairTy VisitInitListExpr(InitListExpr *E);
251 
252   ComplexPairTy VisitVAArgExpr(VAArgExpr *E);
253 };
254 }  // end anonymous namespace.
255 
256 //===----------------------------------------------------------------------===//
257 //                                Utilities
258 //===----------------------------------------------------------------------===//
259 
260 /// EmitLoadOfComplex - Given an RValue reference for a complex, emit code to
261 /// load the real and imaginary pieces, returning them as Real/Imag.
262 ComplexPairTy ComplexExprEmitter::EmitLoadOfComplex(llvm::Value *SrcPtr,
263                                                     bool isVolatile) {
264   llvm::SmallString<64> Name(SrcPtr->getNameStart(),
265                              SrcPtr->getNameStart()+SrcPtr->getNameLen());
266 
267   llvm::Value *Real=0, *Imag=0;
268 
269   if (!IgnoreReal) {
270     Name += ".realp";
271     llvm::Value *RealPtr = Builder.CreateStructGEP(SrcPtr, 0, Name.c_str());
272 
273     Name.pop_back();  // .realp -> .real
274     Real = Builder.CreateLoad(RealPtr, isVolatile, Name.c_str());
275     Name.resize(Name.size()-4); // .real -> .imagp
276   }
277 
278   if (!IgnoreImag) {
279     Name += "imagp";
280 
281     llvm::Value *ImagPtr = Builder.CreateStructGEP(SrcPtr, 1, Name.c_str());
282 
283     Name.pop_back();  // .imagp -> .imag
284     Imag = Builder.CreateLoad(ImagPtr, isVolatile, Name.c_str());
285   }
286   return ComplexPairTy(Real, Imag);
287 }
288 
289 /// EmitStoreOfComplex - Store the specified real/imag parts into the
290 /// specified value pointer.
291 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *Ptr,
292                                             bool isVolatile) {
293   llvm::Value *RealPtr = Builder.CreateStructGEP(Ptr, 0, "real");
294   llvm::Value *ImagPtr = Builder.CreateStructGEP(Ptr, 1, "imag");
295 
296   Builder.CreateStore(Val.first, RealPtr, isVolatile);
297   Builder.CreateStore(Val.second, ImagPtr, isVolatile);
298 }
299 
300 
301 
302 //===----------------------------------------------------------------------===//
303 //                            Visitor Methods
304 //===----------------------------------------------------------------------===//
305 
306 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
307   CGF.ErrorUnsupported(E, "complex expression");
308   const llvm::Type *EltTy =
309     CGF.ConvertType(E->getType()->getAsComplexType()->getElementType());
310   llvm::Value *U = llvm::UndefValue::get(EltTy);
311   return ComplexPairTy(U, U);
312 }
313 
314 ComplexPairTy ComplexExprEmitter::
315 VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
316   llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
317   return
318         ComplexPairTy(CGF.getLLVMContext().getNullValue(Imag->getType()), Imag);
319 }
320 
321 
322 ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
323   if (E->getCallReturnType()->isReferenceType())
324     return EmitLoadOfLValue(E);
325 
326   return CGF.EmitCallExpr(E).getComplexVal();
327 }
328 
329 ComplexPairTy ComplexExprEmitter::VisitStmtExpr(const StmtExpr *E) {
330   return CGF.EmitCompoundStmt(*E->getSubStmt(), true).getComplexVal();
331 }
332 
333 /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
334 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
335                                                            QualType SrcType,
336                                                            QualType DestType) {
337   // Get the src/dest element type.
338   SrcType = SrcType->getAsComplexType()->getElementType();
339   DestType = DestType->getAsComplexType()->getElementType();
340 
341   // C99 6.3.1.6: When a value of complex type is converted to another
342   // complex type, both the real and imaginary parts follow the conversion
343   // rules for the corresponding real types.
344   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType);
345   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType);
346   return Val;
347 }
348 
349 ComplexPairTy ComplexExprEmitter::EmitCast(Expr *Op, QualType DestTy) {
350   // Two cases here: cast from (complex to complex) and (scalar to complex).
351   if (Op->getType()->isAnyComplexType())
352     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
353 
354   // C99 6.3.1.7: When a value of real type is converted to a complex type, the
355   // real part of the complex result value is determined by the rules of
356   // conversion to the corresponding real type and the imaginary part of the
357   // complex result value is a positive zero or an unsigned zero.
358   llvm::Value *Elt = CGF.EmitScalarExpr(Op);
359 
360   // Convert the input element to the element type of the complex.
361   DestTy = DestTy->getAsComplexType()->getElementType();
362   Elt = CGF.EmitScalarConversion(Elt, Op->getType(), DestTy);
363 
364   // Return (realval, 0).
365   return ComplexPairTy(Elt, CGF.getLLVMContext().getNullValue(Elt->getType()));
366 }
367 
368 ComplexPairTy ComplexExprEmitter::VisitPrePostIncDec(const UnaryOperator *E,
369                                                      bool isInc, bool isPre) {
370   LValue LV = CGF.EmitLValue(E->getSubExpr());
371   ComplexPairTy InVal = EmitLoadOfComplex(LV.getAddress(),
372                                           LV.isVolatileQualified());
373 
374   llvm::Value *NextVal;
375   if (isa<llvm::IntegerType>(InVal.first->getType())) {
376     uint64_t AmountVal = isInc ? 1 : -1;
377     NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
378 
379     // Add the inc/dec to the real part.
380     NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
381 
382   } else {
383     QualType ElemTy = E->getType()->getAsComplexType()->getElementType();
384     llvm::APFloat FVal(CGF.getContext().getFloatTypeSemantics(ElemTy), 1);
385     if (!isInc)
386       FVal.changeSign();
387     NextVal = llvm::ConstantFP::get(FVal);
388 
389     // Add the inc/dec to the real part.
390     NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
391   }
392 
393   ComplexPairTy IncVal(NextVal, InVal.second);
394 
395   // Store the updated result through the lvalue.
396   EmitStoreOfComplex(IncVal, LV.getAddress(), LV.isVolatileQualified());
397 
398   // If this is a postinc, return the value read from memory, otherwise use the
399   // updated value.
400   return isPre ? IncVal : InVal;
401 }
402 
403 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
404   TestAndClearIgnoreReal();
405   TestAndClearIgnoreImag();
406   TestAndClearIgnoreRealAssign();
407   TestAndClearIgnoreImagAssign();
408   ComplexPairTy Op = Visit(E->getSubExpr());
409 
410   llvm::Value *ResR, *ResI;
411   if (Op.first->getType()->isFloatingPoint()) {
412     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
413     ResI = Builder.CreateFNeg(Op.second, "neg.i");
414   } else {
415     ResR = Builder.CreateNeg(Op.first,  "neg.r");
416     ResI = Builder.CreateNeg(Op.second, "neg.i");
417   }
418   return ComplexPairTy(ResR, ResI);
419 }
420 
421 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
422   TestAndClearIgnoreReal();
423   TestAndClearIgnoreImag();
424   TestAndClearIgnoreRealAssign();
425   TestAndClearIgnoreImagAssign();
426   // ~(a+ib) = a + i*-b
427   ComplexPairTy Op = Visit(E->getSubExpr());
428   llvm::Value *ResI;
429   if (Op.second->getType()->isFloatingPoint())
430     ResI = Builder.CreateFNeg(Op.second, "conj.i");
431   else
432     ResI = Builder.CreateNeg(Op.second, "conj.i");
433 
434   return ComplexPairTy(Op.first, ResI);
435 }
436 
437 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
438   llvm::Value *ResR, *ResI;
439 
440   if (Op.LHS.first->getType()->isFloatingPoint()) {
441     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
442     ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
443   } else {
444     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
445     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
446   }
447   return ComplexPairTy(ResR, ResI);
448 }
449 
450 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
451   llvm::Value *ResR, *ResI;
452   if (Op.LHS.first->getType()->isFloatingPoint()) {
453     ResR = Builder.CreateFSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
454     ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
455   } else {
456     ResR = Builder.CreateSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
457     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
458   }
459   return ComplexPairTy(ResR, ResI);
460 }
461 
462 
463 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
464   using llvm::Value;
465   Value *ResR, *ResI;
466 
467   if (Op.LHS.first->getType()->isFloatingPoint()) {
468     Value *ResRl = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
469     Value *ResRr = Builder.CreateFMul(Op.LHS.second, Op.RHS.second,"mul.rr");
470     ResR  = Builder.CreateFSub(ResRl, ResRr, "mul.r");
471 
472     Value *ResIl = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il");
473     Value *ResIr = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
474     ResI  = Builder.CreateFAdd(ResIl, ResIr, "mul.i");
475   } else {
476     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
477     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
478     ResR  = Builder.CreateSub(ResRl, ResRr, "mul.r");
479 
480     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
481     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
482     ResI  = Builder.CreateAdd(ResIl, ResIr, "mul.i");
483   }
484   return ComplexPairTy(ResR, ResI);
485 }
486 
487 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
488   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
489   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
490 
491 
492   llvm::Value *DSTr, *DSTi;
493   if (Op.LHS.first->getType()->isFloatingPoint()) {
494     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
495     llvm::Value *Tmp1 = Builder.CreateFMul(LHSr, RHSr, "tmp"); // a*c
496     llvm::Value *Tmp2 = Builder.CreateFMul(LHSi, RHSi, "tmp"); // b*d
497     llvm::Value *Tmp3 = Builder.CreateFAdd(Tmp1, Tmp2, "tmp"); // ac+bd
498 
499     llvm::Value *Tmp4 = Builder.CreateFMul(RHSr, RHSr, "tmp"); // c*c
500     llvm::Value *Tmp5 = Builder.CreateFMul(RHSi, RHSi, "tmp"); // d*d
501     llvm::Value *Tmp6 = Builder.CreateFAdd(Tmp4, Tmp5, "tmp"); // cc+dd
502 
503     llvm::Value *Tmp7 = Builder.CreateFMul(LHSi, RHSr, "tmp"); // b*c
504     llvm::Value *Tmp8 = Builder.CreateFMul(LHSr, RHSi, "tmp"); // a*d
505     llvm::Value *Tmp9 = Builder.CreateFSub(Tmp7, Tmp8, "tmp"); // bc-ad
506 
507     DSTr = Builder.CreateFDiv(Tmp3, Tmp6, "tmp");
508     DSTi = Builder.CreateFDiv(Tmp9, Tmp6, "tmp");
509   } else {
510     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
511     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr, "tmp"); // a*c
512     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi, "tmp"); // b*d
513     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2, "tmp"); // ac+bd
514 
515     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr, "tmp"); // c*c
516     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi, "tmp"); // d*d
517     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5, "tmp"); // cc+dd
518 
519     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr, "tmp"); // b*c
520     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi, "tmp"); // a*d
521     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8, "tmp"); // bc-ad
522 
523     if (Op.Ty->getAsComplexType()->getElementType()->isUnsignedIntegerType()) {
524       DSTr = Builder.CreateUDiv(Tmp3, Tmp6, "tmp");
525       DSTi = Builder.CreateUDiv(Tmp9, Tmp6, "tmp");
526     } else {
527       DSTr = Builder.CreateSDiv(Tmp3, Tmp6, "tmp");
528       DSTi = Builder.CreateSDiv(Tmp9, Tmp6, "tmp");
529     }
530   }
531 
532   return ComplexPairTy(DSTr, DSTi);
533 }
534 
535 ComplexExprEmitter::BinOpInfo
536 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
537   TestAndClearIgnoreReal();
538   TestAndClearIgnoreImag();
539   TestAndClearIgnoreRealAssign();
540   TestAndClearIgnoreImagAssign();
541   BinOpInfo Ops;
542   Ops.LHS = Visit(E->getLHS());
543   Ops.RHS = Visit(E->getRHS());
544   Ops.Ty = E->getType();
545   return Ops;
546 }
547 
548 
549 // Compound assignments.
550 ComplexPairTy ComplexExprEmitter::
551 EmitCompoundAssign(const CompoundAssignOperator *E,
552                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
553   TestAndClearIgnoreReal();
554   TestAndClearIgnoreImag();
555   bool ignreal = TestAndClearIgnoreRealAssign();
556   bool ignimag = TestAndClearIgnoreImagAssign();
557   QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType();
558 
559   BinOpInfo OpInfo;
560 
561   // Load the RHS and LHS operands.
562   // __block variables need to have the rhs evaluated first, plus this should
563   // improve codegen a little.  It is possible for the RHS to be complex or
564   // scalar.
565   OpInfo.Ty = E->getComputationResultType();
566   OpInfo.RHS = EmitCast(E->getRHS(), OpInfo.Ty);
567 
568   LValue LHSLV = CGF.EmitLValue(E->getLHS());
569 
570 
571   // We know the LHS is a complex lvalue.
572   OpInfo.LHS=EmitLoadOfComplex(LHSLV.getAddress(),LHSLV.isVolatileQualified());
573   OpInfo.LHS=EmitComplexToComplexCast(OpInfo.LHS, LHSTy, OpInfo.Ty);
574 
575   // Expand the binary operator.
576   ComplexPairTy Result = (this->*Func)(OpInfo);
577 
578   // Truncate the result back to the LHS type.
579   Result = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
580 
581   // Store the result value into the LHS lvalue.
582   EmitStoreOfComplex(Result, LHSLV.getAddress(), LHSLV.isVolatileQualified());
583   // And now return the LHS
584   IgnoreReal = ignreal;
585   IgnoreImag = ignimag;
586   IgnoreRealAssign = ignreal;
587   IgnoreImagAssign = ignimag;
588   return EmitLoadOfComplex(LHSLV.getAddress(), LHSLV.isVolatileQualified());
589 }
590 
591 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
592   TestAndClearIgnoreReal();
593   TestAndClearIgnoreImag();
594   bool ignreal = TestAndClearIgnoreRealAssign();
595   bool ignimag = TestAndClearIgnoreImagAssign();
596   assert(CGF.getContext().getCanonicalType(E->getLHS()->getType()) ==
597          CGF.getContext().getCanonicalType(E->getRHS()->getType()) &&
598          "Invalid assignment");
599   // Emit the RHS.
600   ComplexPairTy Val = Visit(E->getRHS());
601 
602   // Compute the address to store into.
603   LValue LHS = CGF.EmitLValue(E->getLHS());
604 
605   // Store into it, if simple.
606   if (LHS.isSimple()) {
607     EmitStoreOfComplex(Val, LHS.getAddress(), LHS.isVolatileQualified());
608 
609     // And now return the LHS
610     IgnoreReal = ignreal;
611     IgnoreImag = ignimag;
612     IgnoreRealAssign = ignreal;
613     IgnoreImagAssign = ignimag;
614     return EmitLoadOfComplex(LHS.getAddress(), LHS.isVolatileQualified());
615   }
616 
617   // Otherwise we must have a property setter (no complex vector/bitfields).
618   if (LHS.isPropertyRef())
619     CGF.EmitObjCPropertySet(LHS.getPropertyRefExpr(), RValue::getComplex(Val));
620   else
621     CGF.EmitObjCPropertySet(LHS.getKVCRefExpr(), RValue::getComplex(Val));
622 
623   // There is no reload after a store through a method, but we need to restore
624   // the Ignore* flags.
625   IgnoreReal = ignreal;
626   IgnoreImag = ignimag;
627   IgnoreRealAssign = ignreal;
628   IgnoreImagAssign = ignimag;
629   return Val;
630 }
631 
632 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
633   CGF.EmitStmt(E->getLHS());
634   CGF.EnsureInsertPoint();
635   return Visit(E->getRHS());
636 }
637 
638 ComplexPairTy ComplexExprEmitter::
639 VisitConditionalOperator(const ConditionalOperator *E) {
640   TestAndClearIgnoreReal();
641   TestAndClearIgnoreImag();
642   TestAndClearIgnoreRealAssign();
643   TestAndClearIgnoreImagAssign();
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   llvm::Value *Cond = CGF.EvaluateExprAsBool(E->getCond());
649   Builder.CreateCondBr(Cond, LHSBlock, RHSBlock);
650 
651   CGF.EmitBlock(LHSBlock);
652 
653   // Handle the GNU extension for missing LHS.
654   assert(E->getLHS() && "Must have LHS for complex value");
655 
656   ComplexPairTy LHS = Visit(E->getLHS());
657   LHSBlock = Builder.GetInsertBlock();
658   CGF.EmitBranch(ContBlock);
659 
660   CGF.EmitBlock(RHSBlock);
661 
662   ComplexPairTy RHS = Visit(E->getRHS());
663   RHSBlock = Builder.GetInsertBlock();
664   CGF.EmitBranch(ContBlock);
665 
666   CGF.EmitBlock(ContBlock);
667 
668   // Create a PHI node for the real part.
669   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), "cond.r");
670   RealPN->reserveOperandSpace(2);
671   RealPN->addIncoming(LHS.first, LHSBlock);
672   RealPN->addIncoming(RHS.first, RHSBlock);
673 
674   // Create a PHI node for the imaginary part.
675   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), "cond.i");
676   ImagPN->reserveOperandSpace(2);
677   ImagPN->addIncoming(LHS.second, LHSBlock);
678   ImagPN->addIncoming(RHS.second, RHSBlock);
679 
680   return ComplexPairTy(RealPN, ImagPN);
681 }
682 
683 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
684   return Visit(E->getChosenSubExpr(CGF.getContext()));
685 }
686 
687 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
688     bool Ignore = TestAndClearIgnoreReal();
689     (void)Ignore;
690     assert (Ignore == false && "init list ignored");
691     Ignore = TestAndClearIgnoreImag();
692     (void)Ignore;
693     assert (Ignore == false && "init list ignored");
694   if (E->getNumInits())
695     return Visit(E->getInit(0));
696 
697   // Empty init list intializes to null
698   QualType Ty = E->getType()->getAsComplexType()->getElementType();
699   const llvm::Type* LTy = CGF.ConvertType(Ty);
700   llvm::Value* zeroConstant = CGF.getLLVMContext().getNullValue(LTy);
701   return ComplexPairTy(zeroConstant, zeroConstant);
702 }
703 
704 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
705   llvm::Value *ArgValue = CGF.EmitVAListRef(E->getSubExpr());
706   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, E->getType());
707 
708   if (!ArgPtr) {
709     CGF.ErrorUnsupported(E, "complex va_arg expression");
710     const llvm::Type *EltTy =
711       CGF.ConvertType(E->getType()->getAsComplexType()->getElementType());
712     llvm::Value *U = llvm::UndefValue::get(EltTy);
713     return ComplexPairTy(U, U);
714   }
715 
716   // FIXME Volatility.
717   return EmitLoadOfComplex(ArgPtr, false);
718 }
719 
720 //===----------------------------------------------------------------------===//
721 //                         Entry Point into this File
722 //===----------------------------------------------------------------------===//
723 
724 /// EmitComplexExpr - Emit the computation of the specified expression of
725 /// complex type, ignoring the result.
726 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
727                                                bool IgnoreImag, bool IgnoreRealAssign, bool IgnoreImagAssign) {
728   assert(E && E->getType()->isAnyComplexType() &&
729          "Invalid complex expression to emit");
730 
731   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag, IgnoreRealAssign,
732                             IgnoreImagAssign)
733     .Visit(const_cast<Expr*>(E));
734 }
735 
736 /// EmitComplexExprIntoAddr - Emit the computation of the specified expression
737 /// of complex type, storing into the specified Value*.
738 void CodeGenFunction::EmitComplexExprIntoAddr(const Expr *E,
739                                               llvm::Value *DestAddr,
740                                               bool DestIsVolatile) {
741   assert(E && E->getType()->isAnyComplexType() &&
742          "Invalid complex expression to emit");
743   ComplexExprEmitter Emitter(*this);
744   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
745   Emitter.EmitStoreOfComplex(Val, DestAddr, DestIsVolatile);
746 }
747 
748 /// StoreComplexToAddr - Store a complex number into the specified address.
749 void CodeGenFunction::StoreComplexToAddr(ComplexPairTy V,
750                                          llvm::Value *DestAddr,
751                                          bool DestIsVolatile) {
752   ComplexExprEmitter(*this).EmitStoreOfComplex(V, DestAddr, DestIsVolatile);
753 }
754 
755 /// LoadComplexFromAddr - Load a complex number from the specified address.
756 ComplexPairTy CodeGenFunction::LoadComplexFromAddr(llvm::Value *SrcAddr,
757                                                    bool SrcIsVolatile) {
758   return ComplexExprEmitter(*this).EmitLoadOfComplex(SrcAddr, SrcIsVolatile);
759 }
760