1 //===--- CGExprComplex.cpp - Emit LLVM Code for Complex Exprs -------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This contains code to emit Expr nodes with complex types as LLVM code.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "CodeGenFunction.h"
15 #include "CodeGenModule.h"
16 #include "clang/AST/ASTContext.h"
17 #include "clang/AST/StmtVisitor.h"
18 #include "llvm/Constants.h"
19 #include "llvm/Function.h"
20 #include "llvm/ADT/SmallString.h"
21 using namespace clang;
22 using namespace CodeGen;
23 
24 //===----------------------------------------------------------------------===//
25 //                        Complex Expression Emitter
26 //===----------------------------------------------------------------------===//
27 
28 typedef CodeGenFunction::ComplexPairTy ComplexPairTy;
29 
30 namespace  {
31 class ComplexExprEmitter
32   : public StmtVisitor<ComplexExprEmitter, ComplexPairTy> {
33   CodeGenFunction &CGF;
34   CGBuilderTy &Builder;
35   // True is we should ignore the value of a
36   bool IgnoreReal;
37   bool IgnoreImag;
38 public:
39   ComplexExprEmitter(CodeGenFunction &cgf, bool ir=false, bool ii=false)
40     : CGF(cgf), Builder(CGF.Builder), IgnoreReal(ir), IgnoreImag(ii) {
41   }
42 
43 
44   //===--------------------------------------------------------------------===//
45   //                               Utilities
46   //===--------------------------------------------------------------------===//
47 
48   bool TestAndClearIgnoreReal() {
49     bool I = IgnoreReal;
50     IgnoreReal = false;
51     return I;
52   }
53   bool TestAndClearIgnoreImag() {
54     bool I = IgnoreImag;
55     IgnoreImag = false;
56     return I;
57   }
58 
59   /// EmitLoadOfLValue - Given an expression with complex type that represents a
60   /// value l-value, this method emits the address of the l-value, then loads
61   /// and returns the result.
62   ComplexPairTy EmitLoadOfLValue(const Expr *E) {
63     return EmitLoadOfLValue(CGF.EmitLValue(E));
64   }
65 
66   ComplexPairTy EmitLoadOfLValue(LValue LV) {
67     if (LV.isSimple())
68       return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
69 
70     assert(LV.isPropertyRef() && "Unknown LValue type!");
71     return CGF.EmitLoadOfPropertyRefLValue(LV).getComplexVal();
72   }
73 
74   /// EmitLoadOfComplex - Given a pointer to a complex value, emit code to load
75   /// the real and imaginary pieces.
76   ComplexPairTy EmitLoadOfComplex(llvm::Value *SrcPtr, bool isVolatile);
77 
78   /// EmitStoreThroughLValue - Given an l-value of complex type, store
79   /// a complex number into it.
80   void EmitStoreThroughLValue(ComplexPairTy Val, LValue LV) {
81     if (LV.isSimple())
82       return EmitStoreOfComplex(Val, LV.getAddress(), LV.isVolatileQualified());
83 
84     assert(LV.isPropertyRef() && "Unknown LValue type!");
85     CGF.EmitStoreThroughPropertyRefLValue(RValue::getComplex(Val), LV);
86   }
87 
88   /// EmitStoreOfComplex - Store the specified real/imag parts into the
89   /// specified value pointer.
90   void EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *ResPtr, bool isVol);
91 
92   /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
93   ComplexPairTy EmitComplexToComplexCast(ComplexPairTy Val, QualType SrcType,
94                                          QualType DestType);
95 
96   //===--------------------------------------------------------------------===//
97   //                            Visitor Methods
98   //===--------------------------------------------------------------------===//
99 
100   ComplexPairTy Visit(Expr *E) {
101     llvm::DenseMap<const Expr *, ComplexPairTy>::iterator I =
102       CGF.ConditionalSaveComplexExprs.find(E);
103     if (I != CGF.ConditionalSaveComplexExprs.end())
104       return I->second;
105 
106       return StmtVisitor<ComplexExprEmitter, ComplexPairTy>::Visit(E);
107   }
108 
109   ComplexPairTy VisitStmt(Stmt *S) {
110     S->dump(CGF.getContext().getSourceManager());
111     assert(0 && "Stmt can't have complex result type!");
112     return ComplexPairTy();
113   }
114   ComplexPairTy VisitExpr(Expr *S);
115   ComplexPairTy VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr());}
116   ComplexPairTy VisitImaginaryLiteral(const ImaginaryLiteral *IL);
117 
118   // l-values.
119   ComplexPairTy VisitDeclRefExpr(const Expr *E) { return EmitLoadOfLValue(E); }
120   ComplexPairTy VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
121     return EmitLoadOfLValue(E);
122   }
123   ComplexPairTy VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
124     assert(E->getObjectKind() == OK_Ordinary);
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   ComplexPairTy VisitOpaqueValueExpr(OpaqueValueExpr *E) {
133     if (E->isGLValue())
134       return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E));
135     return CGF.getOpaqueRValueMapping(E).getComplexVal();
136   }
137 
138   // FIXME: CompoundLiteralExpr
139 
140   ComplexPairTy EmitCast(CastExpr::CastKind CK, Expr *Op, QualType DestTy);
141   ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
142     // Unlike for scalars, we don't have to worry about function->ptr demotion
143     // here.
144     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
145   }
146   ComplexPairTy VisitCastExpr(CastExpr *E) {
147     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
148   }
149   ComplexPairTy VisitCallExpr(const CallExpr *E);
150   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
151 
152   // Operators.
153   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
154                                    bool isInc, bool isPre) {
155     LValue LV = CGF.EmitLValue(E->getSubExpr());
156     return CGF.EmitComplexPrePostIncDec(E, LV, isInc, isPre);
157   }
158   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
159     return VisitPrePostIncDec(E, false, false);
160   }
161   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
162     return VisitPrePostIncDec(E, true, false);
163   }
164   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
165     return VisitPrePostIncDec(E, false, true);
166   }
167   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
168     return VisitPrePostIncDec(E, true, true);
169   }
170   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
171   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
172     TestAndClearIgnoreReal();
173     TestAndClearIgnoreImag();
174     return Visit(E->getSubExpr());
175   }
176   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
177   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
178   // LNot,Real,Imag never return complex.
179   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
180     return Visit(E->getSubExpr());
181   }
182   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
183     return Visit(DAE->getExpr());
184   }
185   ComplexPairTy VisitExprWithCleanups(ExprWithCleanups *E) {
186     return CGF.EmitExprWithCleanups(E).getComplexVal();
187   }
188   ComplexPairTy VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
189     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
190     QualType Elem = E->getType()->getAs<ComplexType>()->getElementType();
191     llvm::Constant *Null = llvm::Constant::getNullValue(CGF.ConvertType(Elem));
192     return ComplexPairTy(Null, Null);
193   }
194   ComplexPairTy VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
195     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
196     QualType Elem = E->getType()->getAs<ComplexType>()->getElementType();
197     llvm::Constant *Null =
198                        llvm::Constant::getNullValue(CGF.ConvertType(Elem));
199     return ComplexPairTy(Null, Null);
200   }
201 
202   struct BinOpInfo {
203     ComplexPairTy LHS;
204     ComplexPairTy RHS;
205     QualType Ty;  // Computation Type.
206   };
207 
208   BinOpInfo EmitBinOps(const BinaryOperator *E);
209   LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
210                                   ComplexPairTy (ComplexExprEmitter::*Func)
211                                   (const BinOpInfo &),
212                                   ComplexPairTy &Val);
213   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
214                                    ComplexPairTy (ComplexExprEmitter::*Func)
215                                    (const BinOpInfo &));
216 
217   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
218   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
219   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
220   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
221 
222   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
223     return EmitBinAdd(EmitBinOps(E));
224   }
225   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
226     return EmitBinSub(EmitBinOps(E));
227   }
228   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
229     return EmitBinMul(EmitBinOps(E));
230   }
231   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
232     return EmitBinDiv(EmitBinOps(E));
233   }
234 
235   // Compound assignments.
236   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
237     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
238   }
239   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
240     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
241   }
242   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
243     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
244   }
245   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
246     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
247   }
248 
249   // GCC rejects rem/and/or/xor for integer complex.
250   // Logical and/or always return int, never complex.
251 
252   // No comparisons produce a complex result.
253 
254   LValue EmitBinAssignLValue(const BinaryOperator *E,
255                              ComplexPairTy &Val);
256   ComplexPairTy VisitBinAssign     (const BinaryOperator *E);
257   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
258 
259 
260   ComplexPairTy
261   VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
262   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
263 
264   ComplexPairTy VisitInitListExpr(InitListExpr *E);
265 
266   ComplexPairTy VisitVAArgExpr(VAArgExpr *E);
267 };
268 }  // end anonymous namespace.
269 
270 //===----------------------------------------------------------------------===//
271 //                                Utilities
272 //===----------------------------------------------------------------------===//
273 
274 /// EmitLoadOfComplex - Given an RValue reference for a complex, emit code to
275 /// load the real and imaginary pieces, returning them as Real/Imag.
276 ComplexPairTy ComplexExprEmitter::EmitLoadOfComplex(llvm::Value *SrcPtr,
277                                                     bool isVolatile) {
278   llvm::Value *Real=0, *Imag=0;
279 
280   if (!IgnoreReal || isVolatile) {
281     llvm::Value *RealP = Builder.CreateStructGEP(SrcPtr, 0,
282                                                  SrcPtr->getName() + ".realp");
283     Real = Builder.CreateLoad(RealP, isVolatile, SrcPtr->getName() + ".real");
284   }
285 
286   if (!IgnoreImag || isVolatile) {
287     llvm::Value *ImagP = Builder.CreateStructGEP(SrcPtr, 1,
288                                                  SrcPtr->getName() + ".imagp");
289     Imag = Builder.CreateLoad(ImagP, isVolatile, SrcPtr->getName() + ".imag");
290   }
291   return ComplexPairTy(Real, Imag);
292 }
293 
294 /// EmitStoreOfComplex - Store the specified real/imag parts into the
295 /// specified value pointer.
296 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *Ptr,
297                                             bool isVolatile) {
298   llvm::Value *RealPtr = Builder.CreateStructGEP(Ptr, 0, "real");
299   llvm::Value *ImagPtr = Builder.CreateStructGEP(Ptr, 1, "imag");
300 
301   Builder.CreateStore(Val.first, RealPtr, isVolatile);
302   Builder.CreateStore(Val.second, ImagPtr, isVolatile);
303 }
304 
305 
306 
307 //===----------------------------------------------------------------------===//
308 //                            Visitor Methods
309 //===----------------------------------------------------------------------===//
310 
311 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
312   CGF.ErrorUnsupported(E, "complex expression");
313   const llvm::Type *EltTy =
314     CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
315   llvm::Value *U = llvm::UndefValue::get(EltTy);
316   return ComplexPairTy(U, U);
317 }
318 
319 ComplexPairTy ComplexExprEmitter::
320 VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
321   llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
322   return ComplexPairTy(llvm::Constant::getNullValue(Imag->getType()), Imag);
323 }
324 
325 
326 ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
327   if (E->getCallReturnType()->isReferenceType())
328     return EmitLoadOfLValue(E);
329 
330   return CGF.EmitCallExpr(E).getComplexVal();
331 }
332 
333 ComplexPairTy ComplexExprEmitter::VisitStmtExpr(const StmtExpr *E) {
334   CodeGenFunction::StmtExprEvaluation eval(CGF);
335   return CGF.EmitCompoundStmt(*E->getSubStmt(), true).getComplexVal();
336 }
337 
338 /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
339 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
340                                                            QualType SrcType,
341                                                            QualType DestType) {
342   // Get the src/dest element type.
343   SrcType = SrcType->getAs<ComplexType>()->getElementType();
344   DestType = DestType->getAs<ComplexType>()->getElementType();
345 
346   // C99 6.3.1.6: When a value of complex type is converted to another
347   // complex type, both the real and imaginary parts follow the conversion
348   // rules for the corresponding real types.
349   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType);
350   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType);
351   return Val;
352 }
353 
354 ComplexPairTy ComplexExprEmitter::EmitCast(CastExpr::CastKind CK, Expr *Op,
355                                            QualType DestTy) {
356   switch (CK) {
357   case CK_GetObjCProperty: {
358     LValue LV = CGF.EmitLValue(Op);
359     assert(LV.isPropertyRef() && "Unknown LValue type!");
360     return CGF.EmitLoadOfPropertyRefLValue(LV).getComplexVal();
361   }
362 
363   case CK_NoOp:
364   case CK_LValueToRValue:
365     return Visit(Op);
366 
367   // TODO: do all of these
368   default:
369     break;
370   }
371 
372   // Two cases here: cast from (complex to complex) and (scalar to complex).
373   if (Op->getType()->isAnyComplexType())
374     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
375 
376   // FIXME: We should be looking at all of the cast kinds here, not
377   // cherry-picking the ones we have test cases for.
378   if (CK == CK_LValueBitCast) {
379     llvm::Value *V = CGF.EmitLValue(Op).getAddress();
380     V = Builder.CreateBitCast(V,
381                       CGF.ConvertType(CGF.getContext().getPointerType(DestTy)));
382     // FIXME: Are the qualifiers correct here?
383     return EmitLoadOfComplex(V, DestTy.isVolatileQualified());
384   }
385 
386   // C99 6.3.1.7: When a value of real type is converted to a complex type, the
387   // real part of the complex result value is determined by the rules of
388   // conversion to the corresponding real type and the imaginary part of the
389   // complex result value is a positive zero or an unsigned zero.
390   llvm::Value *Elt = CGF.EmitScalarExpr(Op);
391 
392   // Convert the input element to the element type of the complex.
393   DestTy = DestTy->getAs<ComplexType>()->getElementType();
394   Elt = CGF.EmitScalarConversion(Elt, Op->getType(), DestTy);
395 
396   // Return (realval, 0).
397   return ComplexPairTy(Elt, llvm::Constant::getNullValue(Elt->getType()));
398 }
399 
400 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
401   TestAndClearIgnoreReal();
402   TestAndClearIgnoreImag();
403   ComplexPairTy Op = Visit(E->getSubExpr());
404 
405   llvm::Value *ResR, *ResI;
406   if (Op.first->getType()->isFloatingPointTy()) {
407     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
408     ResI = Builder.CreateFNeg(Op.second, "neg.i");
409   } else {
410     ResR = Builder.CreateNeg(Op.first,  "neg.r");
411     ResI = Builder.CreateNeg(Op.second, "neg.i");
412   }
413   return ComplexPairTy(ResR, ResI);
414 }
415 
416 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
417   TestAndClearIgnoreReal();
418   TestAndClearIgnoreImag();
419   // ~(a+ib) = a + i*-b
420   ComplexPairTy Op = Visit(E->getSubExpr());
421   llvm::Value *ResI;
422   if (Op.second->getType()->isFloatingPointTy())
423     ResI = Builder.CreateFNeg(Op.second, "conj.i");
424   else
425     ResI = Builder.CreateNeg(Op.second, "conj.i");
426 
427   return ComplexPairTy(Op.first, ResI);
428 }
429 
430 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
431   llvm::Value *ResR, *ResI;
432 
433   if (Op.LHS.first->getType()->isFloatingPointTy()) {
434     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
435     ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
436   } else {
437     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
438     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
439   }
440   return ComplexPairTy(ResR, ResI);
441 }
442 
443 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
444   llvm::Value *ResR, *ResI;
445   if (Op.LHS.first->getType()->isFloatingPointTy()) {
446     ResR = Builder.CreateFSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
447     ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
448   } else {
449     ResR = Builder.CreateSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
450     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
451   }
452   return ComplexPairTy(ResR, ResI);
453 }
454 
455 
456 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
457   using llvm::Value;
458   Value *ResR, *ResI;
459 
460   if (Op.LHS.first->getType()->isFloatingPointTy()) {
461     Value *ResRl = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
462     Value *ResRr = Builder.CreateFMul(Op.LHS.second, Op.RHS.second,"mul.rr");
463     ResR  = Builder.CreateFSub(ResRl, ResRr, "mul.r");
464 
465     Value *ResIl = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il");
466     Value *ResIr = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
467     ResI  = Builder.CreateFAdd(ResIl, ResIr, "mul.i");
468   } else {
469     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
470     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
471     ResR  = Builder.CreateSub(ResRl, ResRr, "mul.r");
472 
473     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
474     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
475     ResI  = Builder.CreateAdd(ResIl, ResIr, "mul.i");
476   }
477   return ComplexPairTy(ResR, ResI);
478 }
479 
480 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
481   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
482   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
483 
484 
485   llvm::Value *DSTr, *DSTi;
486   if (Op.LHS.first->getType()->isFloatingPointTy()) {
487     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
488     llvm::Value *Tmp1 = Builder.CreateFMul(LHSr, RHSr, "tmp"); // a*c
489     llvm::Value *Tmp2 = Builder.CreateFMul(LHSi, RHSi, "tmp"); // b*d
490     llvm::Value *Tmp3 = Builder.CreateFAdd(Tmp1, Tmp2, "tmp"); // ac+bd
491 
492     llvm::Value *Tmp4 = Builder.CreateFMul(RHSr, RHSr, "tmp"); // c*c
493     llvm::Value *Tmp5 = Builder.CreateFMul(RHSi, RHSi, "tmp"); // d*d
494     llvm::Value *Tmp6 = Builder.CreateFAdd(Tmp4, Tmp5, "tmp"); // cc+dd
495 
496     llvm::Value *Tmp7 = Builder.CreateFMul(LHSi, RHSr, "tmp"); // b*c
497     llvm::Value *Tmp8 = Builder.CreateFMul(LHSr, RHSi, "tmp"); // a*d
498     llvm::Value *Tmp9 = Builder.CreateFSub(Tmp7, Tmp8, "tmp"); // bc-ad
499 
500     DSTr = Builder.CreateFDiv(Tmp3, Tmp6, "tmp");
501     DSTi = Builder.CreateFDiv(Tmp9, Tmp6, "tmp");
502   } else {
503     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
504     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr, "tmp"); // a*c
505     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi, "tmp"); // b*d
506     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2, "tmp"); // ac+bd
507 
508     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr, "tmp"); // c*c
509     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi, "tmp"); // d*d
510     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5, "tmp"); // cc+dd
511 
512     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr, "tmp"); // b*c
513     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi, "tmp"); // a*d
514     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8, "tmp"); // bc-ad
515 
516     if (Op.Ty->getAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
517       DSTr = Builder.CreateUDiv(Tmp3, Tmp6, "tmp");
518       DSTi = Builder.CreateUDiv(Tmp9, Tmp6, "tmp");
519     } else {
520       DSTr = Builder.CreateSDiv(Tmp3, Tmp6, "tmp");
521       DSTi = Builder.CreateSDiv(Tmp9, Tmp6, "tmp");
522     }
523   }
524 
525   return ComplexPairTy(DSTr, DSTi);
526 }
527 
528 ComplexExprEmitter::BinOpInfo
529 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
530   TestAndClearIgnoreReal();
531   TestAndClearIgnoreImag();
532   BinOpInfo Ops;
533   Ops.LHS = Visit(E->getLHS());
534   Ops.RHS = Visit(E->getRHS());
535   Ops.Ty = E->getType();
536   return Ops;
537 }
538 
539 
540 LValue ComplexExprEmitter::
541 EmitCompoundAssignLValue(const CompoundAssignOperator *E,
542           ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&),
543                          ComplexPairTy &Val) {
544   TestAndClearIgnoreReal();
545   TestAndClearIgnoreImag();
546   QualType LHSTy = E->getLHS()->getType();
547 
548   BinOpInfo OpInfo;
549 
550   // Load the RHS and LHS operands.
551   // __block variables need to have the rhs evaluated first, plus this should
552   // improve codegen a little.
553   OpInfo.Ty = E->getComputationResultType();
554 
555   // The RHS should have been converted to the computation type.
556   assert(OpInfo.Ty->isAnyComplexType());
557   assert(CGF.getContext().hasSameUnqualifiedType(OpInfo.Ty,
558                                                  E->getRHS()->getType()));
559   OpInfo.RHS = Visit(E->getRHS());
560 
561   LValue LHS = CGF.EmitLValue(E->getLHS());
562 
563   // Load from the l-value.
564   ComplexPairTy LHSComplexPair = EmitLoadOfLValue(LHS);
565 
566   OpInfo.LHS = EmitComplexToComplexCast(LHSComplexPair, LHSTy, OpInfo.Ty);
567 
568   // Expand the binary operator.
569   ComplexPairTy Result = (this->*Func)(OpInfo);
570 
571   // Truncate the result back to the LHS type.
572   Result = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
573   Val = Result;
574 
575   // Store the result value into the LHS lvalue.
576   EmitStoreThroughLValue(Result, LHS);
577 
578   return LHS;
579 }
580 
581 // Compound assignments.
582 ComplexPairTy ComplexExprEmitter::
583 EmitCompoundAssign(const CompoundAssignOperator *E,
584                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
585   ComplexPairTy Val;
586   LValue LV = EmitCompoundAssignLValue(E, Func, Val);
587 
588   // The result of an assignment in C is the assigned r-value.
589   if (!CGF.getContext().getLangOptions().CPlusPlus)
590     return Val;
591 
592   // Objective-C property assignment never reloads the value following a store.
593   if (LV.isPropertyRef())
594     return Val;
595 
596   // If the lvalue is non-volatile, return the computed value of the assignment.
597   if (!LV.isVolatileQualified())
598     return Val;
599 
600   return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
601 }
602 
603 LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
604                                                ComplexPairTy &Val) {
605   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
606                                                  E->getRHS()->getType()) &&
607          "Invalid assignment");
608   TestAndClearIgnoreReal();
609   TestAndClearIgnoreImag();
610 
611   // Emit the RHS.  __block variables need the RHS evaluated first.
612   Val = Visit(E->getRHS());
613 
614   // Compute the address to store into.
615   LValue LHS = CGF.EmitLValue(E->getLHS());
616 
617   // Store the result value into the LHS lvalue.
618   EmitStoreThroughLValue(Val, LHS);
619 
620   return LHS;
621 }
622 
623 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
624   ComplexPairTy Val;
625   LValue LV = EmitBinAssignLValue(E, Val);
626 
627   // The result of an assignment in C is the assigned r-value.
628   if (!CGF.getContext().getLangOptions().CPlusPlus)
629     return Val;
630 
631   // Objective-C property assignment never reloads the value following a store.
632   if (LV.isPropertyRef())
633     return Val;
634 
635   // If the lvalue is non-volatile, return the computed value of the assignment.
636   if (!LV.isVolatileQualified())
637     return Val;
638 
639   return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
640 }
641 
642 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
643   CGF.EmitIgnoredExpr(E->getLHS());
644   return Visit(E->getRHS());
645 }
646 
647 ComplexPairTy ComplexExprEmitter::
648 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
649   TestAndClearIgnoreReal();
650   TestAndClearIgnoreImag();
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   // Bind the common expression if necessary.
656   CodeGenFunction::OpaqueValueMapping binding(CGF, E);
657 
658   CodeGenFunction::ConditionalEvaluation eval(CGF);
659   CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
660 
661   eval.begin(CGF);
662   CGF.EmitBlock(LHSBlock);
663   ComplexPairTy LHS = Visit(E->getTrueExpr());
664   LHSBlock = Builder.GetInsertBlock();
665   CGF.EmitBranch(ContBlock);
666   eval.end(CGF);
667 
668   eval.begin(CGF);
669   CGF.EmitBlock(RHSBlock);
670   ComplexPairTy RHS = Visit(E->getFalseExpr());
671   RHSBlock = Builder.GetInsertBlock();
672   CGF.EmitBlock(ContBlock);
673   eval.end(CGF);
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()->getAs<ComplexType>()->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()->getAs<ComplexType>()->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) {
735   assert(E && E->getType()->isAnyComplexType() &&
736          "Invalid complex expression to emit");
737 
738   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag)
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 
767 LValue CodeGenFunction::EmitComplexAssignmentLValue(const BinaryOperator *E) {
768   assert(E->getOpcode() == BO_Assign);
769   ComplexPairTy Val; // ignored
770   return ComplexExprEmitter(*this).EmitBinAssignLValue(E, Val);
771 }
772 
773 LValue CodeGenFunction::
774 EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E) {
775   ComplexPairTy(ComplexExprEmitter::*Op)(const ComplexExprEmitter::BinOpInfo &);
776   switch (E->getOpcode()) {
777   case BO_MulAssign: Op = &ComplexExprEmitter::EmitBinMul; break;
778   case BO_DivAssign: Op = &ComplexExprEmitter::EmitBinDiv; break;
779   case BO_SubAssign: Op = &ComplexExprEmitter::EmitBinSub; break;
780   case BO_AddAssign: Op = &ComplexExprEmitter::EmitBinAdd; break;
781 
782   default:
783     llvm_unreachable("unexpected complex compound assignment");
784     Op = 0;
785   }
786 
787   ComplexPairTy Val; // ignored
788   return ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
789 }
790