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 VisitObjCImplicitSetterGetterRefExpr(
124                                ObjCImplicitSetterGetterRefExpr *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()->getAs<ComplexType>()->getElementType();
185     llvm::Constant *Null = llvm::Constant::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()->getAs<ComplexType>()->getElementType();
191     llvm::Constant *Null =
192                        llvm::Constant::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->getName().begin(),
265                              SrcPtr->getName().end());
266 
267   llvm::Value *Real=0, *Imag=0;
268 
269   if (!IgnoreReal) {
270     // FIXME: Clean this up once builder takes Twine/StringRef.
271     Name += ".realp";
272     llvm::Value *RealPtr = Builder.CreateStructGEP(SrcPtr, 0,
273                                                    Name.str().str().c_str());
274 
275     Name.pop_back();  // .realp -> .real
276     // FIXME: Clean this up once builder takes Twine/StringRef.
277     Real = Builder.CreateLoad(RealPtr, isVolatile,
278                               Name.str().str().c_str());
279     Name.resize(Name.size()-4); // .real -> .imagp
280   }
281 
282   if (!IgnoreImag) {
283     Name += "imagp";
284 
285     // FIXME: Clean this up once builder takes Twine/StringRef.
286     llvm::Value *ImagPtr = Builder.CreateStructGEP(SrcPtr, 1,
287                                                    Name.str().str().c_str());
288 
289     Name.pop_back();  // .imagp -> .imag
290     // FIXME: Clean this up once builder takes Twine/StringRef.
291     Imag = Builder.CreateLoad(ImagPtr, isVolatile, Name.str().str().c_str());
292   }
293   return ComplexPairTy(Real, Imag);
294 }
295 
296 /// EmitStoreOfComplex - Store the specified real/imag parts into the
297 /// specified value pointer.
298 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *Ptr,
299                                             bool isVolatile) {
300   llvm::Value *RealPtr = Builder.CreateStructGEP(Ptr, 0, "real");
301   llvm::Value *ImagPtr = Builder.CreateStructGEP(Ptr, 1, "imag");
302 
303   Builder.CreateStore(Val.first, RealPtr, isVolatile);
304   Builder.CreateStore(Val.second, ImagPtr, isVolatile);
305 }
306 
307 
308 
309 //===----------------------------------------------------------------------===//
310 //                            Visitor Methods
311 //===----------------------------------------------------------------------===//
312 
313 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
314   CGF.ErrorUnsupported(E, "complex expression");
315   const llvm::Type *EltTy =
316     CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
317   llvm::Value *U = llvm::UndefValue::get(EltTy);
318   return ComplexPairTy(U, U);
319 }
320 
321 ComplexPairTy ComplexExprEmitter::
322 VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
323   llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
324   return
325         ComplexPairTy(llvm::Constant::getNullValue(Imag->getType()), Imag);
326 }
327 
328 
329 ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
330   if (E->getCallReturnType()->isReferenceType())
331     return EmitLoadOfLValue(E);
332 
333   return CGF.EmitCallExpr(E).getComplexVal();
334 }
335 
336 ComplexPairTy ComplexExprEmitter::VisitStmtExpr(const StmtExpr *E) {
337   return CGF.EmitCompoundStmt(*E->getSubStmt(), true).getComplexVal();
338 }
339 
340 /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
341 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
342                                                            QualType SrcType,
343                                                            QualType DestType) {
344   // Get the src/dest element type.
345   SrcType = SrcType->getAs<ComplexType>()->getElementType();
346   DestType = DestType->getAs<ComplexType>()->getElementType();
347 
348   // C99 6.3.1.6: When a value of complex type is converted to another
349   // complex type, both the real and imaginary parts follow the conversion
350   // rules for the corresponding real types.
351   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType);
352   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType);
353   return Val;
354 }
355 
356 ComplexPairTy ComplexExprEmitter::EmitCast(Expr *Op, QualType DestTy) {
357   // Two cases here: cast from (complex to complex) and (scalar to complex).
358   if (Op->getType()->isAnyComplexType())
359     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
360 
361   // C99 6.3.1.7: When a value of real type is converted to a complex type, the
362   // real part of the complex result value is determined by the rules of
363   // conversion to the corresponding real type and the imaginary part of the
364   // complex result value is a positive zero or an unsigned zero.
365   llvm::Value *Elt = CGF.EmitScalarExpr(Op);
366 
367   // Convert the input element to the element type of the complex.
368   DestTy = DestTy->getAs<ComplexType>()->getElementType();
369   Elt = CGF.EmitScalarConversion(Elt, Op->getType(), DestTy);
370 
371   // Return (realval, 0).
372   return ComplexPairTy(Elt, llvm::Constant::getNullValue(Elt->getType()));
373 }
374 
375 ComplexPairTy ComplexExprEmitter::VisitPrePostIncDec(const UnaryOperator *E,
376                                                      bool isInc, bool isPre) {
377   LValue LV = CGF.EmitLValue(E->getSubExpr());
378   ComplexPairTy InVal = EmitLoadOfComplex(LV.getAddress(),
379                                           LV.isVolatileQualified());
380 
381   llvm::Value *NextVal;
382   if (isa<llvm::IntegerType>(InVal.first->getType())) {
383     uint64_t AmountVal = isInc ? 1 : -1;
384     NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
385 
386     // Add the inc/dec to the real part.
387     NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
388   } else {
389     QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
390     llvm::APFloat FVal(CGF.getContext().getFloatTypeSemantics(ElemTy), 1);
391     if (!isInc)
392       FVal.changeSign();
393     NextVal = llvm::ConstantFP::get(CGF.getLLVMContext(), FVal);
394 
395     // Add the inc/dec to the real part.
396     NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
397   }
398 
399   ComplexPairTy IncVal(NextVal, InVal.second);
400 
401   // Store the updated result through the lvalue.
402   EmitStoreOfComplex(IncVal, LV.getAddress(), LV.isVolatileQualified());
403 
404   // If this is a postinc, return the value read from memory, otherwise use the
405   // updated value.
406   return isPre ? IncVal : InVal;
407 }
408 
409 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
410   TestAndClearIgnoreReal();
411   TestAndClearIgnoreImag();
412   TestAndClearIgnoreRealAssign();
413   TestAndClearIgnoreImagAssign();
414   ComplexPairTy Op = Visit(E->getSubExpr());
415 
416   llvm::Value *ResR, *ResI;
417   if (Op.first->getType()->isFloatingPoint()) {
418     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
419     ResI = Builder.CreateFNeg(Op.second, "neg.i");
420   } else {
421     ResR = Builder.CreateNeg(Op.first,  "neg.r");
422     ResI = Builder.CreateNeg(Op.second, "neg.i");
423   }
424   return ComplexPairTy(ResR, ResI);
425 }
426 
427 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
428   TestAndClearIgnoreReal();
429   TestAndClearIgnoreImag();
430   TestAndClearIgnoreRealAssign();
431   TestAndClearIgnoreImagAssign();
432   // ~(a+ib) = a + i*-b
433   ComplexPairTy Op = Visit(E->getSubExpr());
434   llvm::Value *ResI;
435   if (Op.second->getType()->isFloatingPoint())
436     ResI = Builder.CreateFNeg(Op.second, "conj.i");
437   else
438     ResI = Builder.CreateNeg(Op.second, "conj.i");
439 
440   return ComplexPairTy(Op.first, ResI);
441 }
442 
443 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
444   llvm::Value *ResR, *ResI;
445 
446   if (Op.LHS.first->getType()->isFloatingPoint()) {
447     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
448     ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
449   } else {
450     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
451     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
452   }
453   return ComplexPairTy(ResR, ResI);
454 }
455 
456 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
457   llvm::Value *ResR, *ResI;
458   if (Op.LHS.first->getType()->isFloatingPoint()) {
459     ResR = Builder.CreateFSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
460     ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
461   } else {
462     ResR = Builder.CreateSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
463     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
464   }
465   return ComplexPairTy(ResR, ResI);
466 }
467 
468 
469 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
470   using llvm::Value;
471   Value *ResR, *ResI;
472 
473   if (Op.LHS.first->getType()->isFloatingPoint()) {
474     Value *ResRl = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
475     Value *ResRr = Builder.CreateFMul(Op.LHS.second, Op.RHS.second,"mul.rr");
476     ResR  = Builder.CreateFSub(ResRl, ResRr, "mul.r");
477 
478     Value *ResIl = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il");
479     Value *ResIr = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
480     ResI  = Builder.CreateFAdd(ResIl, ResIr, "mul.i");
481   } else {
482     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
483     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
484     ResR  = Builder.CreateSub(ResRl, ResRr, "mul.r");
485 
486     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
487     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
488     ResI  = Builder.CreateAdd(ResIl, ResIr, "mul.i");
489   }
490   return ComplexPairTy(ResR, ResI);
491 }
492 
493 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
494   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
495   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
496 
497 
498   llvm::Value *DSTr, *DSTi;
499   if (Op.LHS.first->getType()->isFloatingPoint()) {
500     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
501     llvm::Value *Tmp1 = Builder.CreateFMul(LHSr, RHSr, "tmp"); // a*c
502     llvm::Value *Tmp2 = Builder.CreateFMul(LHSi, RHSi, "tmp"); // b*d
503     llvm::Value *Tmp3 = Builder.CreateFAdd(Tmp1, Tmp2, "tmp"); // ac+bd
504 
505     llvm::Value *Tmp4 = Builder.CreateFMul(RHSr, RHSr, "tmp"); // c*c
506     llvm::Value *Tmp5 = Builder.CreateFMul(RHSi, RHSi, "tmp"); // d*d
507     llvm::Value *Tmp6 = Builder.CreateFAdd(Tmp4, Tmp5, "tmp"); // cc+dd
508 
509     llvm::Value *Tmp7 = Builder.CreateFMul(LHSi, RHSr, "tmp"); // b*c
510     llvm::Value *Tmp8 = Builder.CreateFMul(LHSr, RHSi, "tmp"); // a*d
511     llvm::Value *Tmp9 = Builder.CreateFSub(Tmp7, Tmp8, "tmp"); // bc-ad
512 
513     DSTr = Builder.CreateFDiv(Tmp3, Tmp6, "tmp");
514     DSTi = Builder.CreateFDiv(Tmp9, Tmp6, "tmp");
515   } else {
516     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
517     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr, "tmp"); // a*c
518     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi, "tmp"); // b*d
519     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2, "tmp"); // ac+bd
520 
521     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr, "tmp"); // c*c
522     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi, "tmp"); // d*d
523     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5, "tmp"); // cc+dd
524 
525     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr, "tmp"); // b*c
526     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi, "tmp"); // a*d
527     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8, "tmp"); // bc-ad
528 
529     if (Op.Ty->getAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
530       DSTr = Builder.CreateUDiv(Tmp3, Tmp6, "tmp");
531       DSTi = Builder.CreateUDiv(Tmp9, Tmp6, "tmp");
532     } else {
533       DSTr = Builder.CreateSDiv(Tmp3, Tmp6, "tmp");
534       DSTi = Builder.CreateSDiv(Tmp9, Tmp6, "tmp");
535     }
536   }
537 
538   return ComplexPairTy(DSTr, DSTi);
539 }
540 
541 ComplexExprEmitter::BinOpInfo
542 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
543   TestAndClearIgnoreReal();
544   TestAndClearIgnoreImag();
545   TestAndClearIgnoreRealAssign();
546   TestAndClearIgnoreImagAssign();
547   BinOpInfo Ops;
548   Ops.LHS = Visit(E->getLHS());
549   Ops.RHS = Visit(E->getRHS());
550   Ops.Ty = E->getType();
551   return Ops;
552 }
553 
554 
555 // Compound assignments.
556 ComplexPairTy ComplexExprEmitter::
557 EmitCompoundAssign(const CompoundAssignOperator *E,
558                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
559   TestAndClearIgnoreReal();
560   TestAndClearIgnoreImag();
561   bool ignreal = TestAndClearIgnoreRealAssign();
562   bool ignimag = TestAndClearIgnoreImagAssign();
563   QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType();
564 
565   BinOpInfo OpInfo;
566 
567   // Load the RHS and LHS operands.
568   // __block variables need to have the rhs evaluated first, plus this should
569   // improve codegen a little.  It is possible for the RHS to be complex or
570   // scalar.
571   OpInfo.Ty = E->getComputationResultType();
572   OpInfo.RHS = EmitCast(E->getRHS(), OpInfo.Ty);
573 
574   LValue LHSLV = CGF.EmitLValue(E->getLHS());
575 
576 
577   // We know the LHS is a complex lvalue.
578   OpInfo.LHS=EmitLoadOfComplex(LHSLV.getAddress(), LHSLV.isVolatileQualified());
579   OpInfo.LHS=EmitComplexToComplexCast(OpInfo.LHS, LHSTy, OpInfo.Ty);
580 
581   // Expand the binary operator.
582   ComplexPairTy Result = (this->*Func)(OpInfo);
583 
584   // Truncate the result back to the LHS type.
585   Result = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
586 
587   // Store the result value into the LHS lvalue.
588   EmitStoreOfComplex(Result, LHSLV.getAddress(), LHSLV.isVolatileQualified());
589   // And now return the LHS
590   IgnoreReal = ignreal;
591   IgnoreImag = ignimag;
592   IgnoreRealAssign = ignreal;
593   IgnoreImagAssign = ignimag;
594   return EmitLoadOfComplex(LHSLV.getAddress(), LHSLV.isVolatileQualified());
595 }
596 
597 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
598   TestAndClearIgnoreReal();
599   TestAndClearIgnoreImag();
600   bool ignreal = TestAndClearIgnoreRealAssign();
601   bool ignimag = TestAndClearIgnoreImagAssign();
602   assert(CGF.getContext().getCanonicalType(E->getLHS()->getType()) ==
603          CGF.getContext().getCanonicalType(E->getRHS()->getType()) &&
604          "Invalid assignment");
605   // Emit the RHS.
606   ComplexPairTy Val = Visit(E->getRHS());
607 
608   // Compute the address to store into.
609   LValue LHS = CGF.EmitLValue(E->getLHS());
610 
611   // Store into it, if simple.
612   if (LHS.isSimple()) {
613     EmitStoreOfComplex(Val, LHS.getAddress(), LHS.isVolatileQualified());
614 
615     // And now return the LHS
616     IgnoreReal = ignreal;
617     IgnoreImag = ignimag;
618     IgnoreRealAssign = ignreal;
619     IgnoreImagAssign = ignimag;
620     return EmitLoadOfComplex(LHS.getAddress(), LHS.isVolatileQualified());
621   }
622 
623   // Otherwise we must have a property setter (no complex vector/bitfields).
624   if (LHS.isPropertyRef())
625     CGF.EmitObjCPropertySet(LHS.getPropertyRefExpr(), RValue::getComplex(Val));
626   else
627     CGF.EmitObjCPropertySet(LHS.getKVCRefExpr(), RValue::getComplex(Val));
628 
629   // There is no reload after a store through a method, but we need to restore
630   // the Ignore* flags.
631   IgnoreReal = ignreal;
632   IgnoreImag = ignimag;
633   IgnoreRealAssign = ignreal;
634   IgnoreImagAssign = ignimag;
635   return Val;
636 }
637 
638 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
639   CGF.EmitStmt(E->getLHS());
640   CGF.EnsureInsertPoint();
641   return Visit(E->getRHS());
642 }
643 
644 ComplexPairTy ComplexExprEmitter::
645 VisitConditionalOperator(const ConditionalOperator *E) {
646   TestAndClearIgnoreReal();
647   TestAndClearIgnoreImag();
648   TestAndClearIgnoreRealAssign();
649   TestAndClearIgnoreImagAssign();
650   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
651   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
652   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
653 
654   llvm::Value *Cond = CGF.EvaluateExprAsBool(E->getCond());
655   Builder.CreateCondBr(Cond, LHSBlock, RHSBlock);
656 
657   CGF.EmitBlock(LHSBlock);
658 
659   // Handle the GNU extension for missing LHS.
660   assert(E->getLHS() && "Must have LHS for complex value");
661 
662   ComplexPairTy LHS = Visit(E->getLHS());
663   LHSBlock = Builder.GetInsertBlock();
664   CGF.EmitBranch(ContBlock);
665 
666   CGF.EmitBlock(RHSBlock);
667 
668   ComplexPairTy RHS = Visit(E->getRHS());
669   RHSBlock = Builder.GetInsertBlock();
670   CGF.EmitBranch(ContBlock);
671 
672   CGF.EmitBlock(ContBlock);
673 
674   // Create a PHI node for the real part.
675   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), "cond.r");
676   RealPN->reserveOperandSpace(2);
677   RealPN->addIncoming(LHS.first, LHSBlock);
678   RealPN->addIncoming(RHS.first, RHSBlock);
679 
680   // Create a PHI node for the imaginary part.
681   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), "cond.i");
682   ImagPN->reserveOperandSpace(2);
683   ImagPN->addIncoming(LHS.second, LHSBlock);
684   ImagPN->addIncoming(RHS.second, RHSBlock);
685 
686   return ComplexPairTy(RealPN, ImagPN);
687 }
688 
689 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
690   return Visit(E->getChosenSubExpr(CGF.getContext()));
691 }
692 
693 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
694     bool Ignore = TestAndClearIgnoreReal();
695     (void)Ignore;
696     assert (Ignore == false && "init list ignored");
697     Ignore = TestAndClearIgnoreImag();
698     (void)Ignore;
699     assert (Ignore == false && "init list ignored");
700   if (E->getNumInits())
701     return Visit(E->getInit(0));
702 
703   // Empty init list intializes to null
704   QualType Ty = E->getType()->getAs<ComplexType>()->getElementType();
705   const llvm::Type* LTy = CGF.ConvertType(Ty);
706   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
707   return ComplexPairTy(zeroConstant, zeroConstant);
708 }
709 
710 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
711   llvm::Value *ArgValue = CGF.EmitVAListRef(E->getSubExpr());
712   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, E->getType());
713 
714   if (!ArgPtr) {
715     CGF.ErrorUnsupported(E, "complex va_arg expression");
716     const llvm::Type *EltTy =
717       CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
718     llvm::Value *U = llvm::UndefValue::get(EltTy);
719     return ComplexPairTy(U, U);
720   }
721 
722   // FIXME Volatility.
723   return EmitLoadOfComplex(ArgPtr, false);
724 }
725 
726 //===----------------------------------------------------------------------===//
727 //                         Entry Point into this File
728 //===----------------------------------------------------------------------===//
729 
730 /// EmitComplexExpr - Emit the computation of the specified expression of
731 /// complex type, ignoring the result.
732 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
733                                                bool IgnoreImag, bool IgnoreRealAssign, bool IgnoreImagAssign) {
734   assert(E && E->getType()->isAnyComplexType() &&
735          "Invalid complex expression to emit");
736 
737   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag, IgnoreRealAssign,
738                             IgnoreImagAssign)
739     .Visit(const_cast<Expr*>(E));
740 }
741 
742 /// EmitComplexExprIntoAddr - Emit the computation of the specified expression
743 /// of complex type, storing into the specified Value*.
744 void CodeGenFunction::EmitComplexExprIntoAddr(const Expr *E,
745                                               llvm::Value *DestAddr,
746                                               bool DestIsVolatile) {
747   assert(E && E->getType()->isAnyComplexType() &&
748          "Invalid complex expression to emit");
749   ComplexExprEmitter Emitter(*this);
750   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
751   Emitter.EmitStoreOfComplex(Val, DestAddr, DestIsVolatile);
752 }
753 
754 /// StoreComplexToAddr - Store a complex number into the specified address.
755 void CodeGenFunction::StoreComplexToAddr(ComplexPairTy V,
756                                          llvm::Value *DestAddr,
757                                          bool DestIsVolatile) {
758   ComplexExprEmitter(*this).EmitStoreOfComplex(V, DestAddr, DestIsVolatile);
759 }
760 
761 /// LoadComplexFromAddr - Load a complex number from the specified address.
762 ComplexPairTy CodeGenFunction::LoadComplexFromAddr(llvm::Value *SrcAddr,
763                                                    bool SrcIsVolatile) {
764   return ComplexExprEmitter(*this).EmitLoadOfComplex(SrcAddr, SrcIsVolatile);
765 }
766