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     assert(LV.isSimple() && "complex l-value must be simple");
68     return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
69   }
70 
71   /// EmitLoadOfComplex - Given a pointer to a complex value, emit code to load
72   /// the real and imaginary pieces.
73   ComplexPairTy EmitLoadOfComplex(llvm::Value *SrcPtr, bool isVolatile);
74 
75   /// EmitStoreThroughLValue - Given an l-value of complex type, store
76   /// a complex number into it.
77   void EmitStoreThroughLValue(ComplexPairTy Val, LValue LV) {
78     assert(LV.isSimple() && "complex l-value must be simple");
79     return EmitStoreOfComplex(Val, LV.getAddress(), LV.isVolatileQualified());
80   }
81 
82   /// EmitStoreOfComplex - Store the specified real/imag parts into the
83   /// specified value pointer.
84   void EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *ResPtr, bool isVol);
85 
86   /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
87   ComplexPairTy EmitComplexToComplexCast(ComplexPairTy Val, QualType SrcType,
88                                          QualType DestType);
89 
90   //===--------------------------------------------------------------------===//
91   //                            Visitor Methods
92   //===--------------------------------------------------------------------===//
93 
94   ComplexPairTy Visit(Expr *E) {
95     return StmtVisitor<ComplexExprEmitter, ComplexPairTy>::Visit(E);
96   }
97 
98   ComplexPairTy VisitStmt(Stmt *S) {
99     S->dump(CGF.getContext().getSourceManager());
100     llvm_unreachable("Stmt can't have complex result type!");
101   }
102   ComplexPairTy VisitExpr(Expr *S);
103   ComplexPairTy VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr());}
104   ComplexPairTy VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
105     return Visit(GE->getResultExpr());
106   }
107   ComplexPairTy VisitImaginaryLiteral(const ImaginaryLiteral *IL);
108   ComplexPairTy
109   VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *PE) {
110     return Visit(PE->getReplacement());
111   }
112 
113   // l-values.
114   ComplexPairTy VisitDeclRefExpr(const Expr *E) { return EmitLoadOfLValue(E); }
115   ComplexPairTy VisitBlockDeclRefExpr(const Expr *E) { return EmitLoadOfLValue(E); }
116   ComplexPairTy VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
117     return EmitLoadOfLValue(E);
118   }
119   ComplexPairTy VisitObjCMessageExpr(ObjCMessageExpr *E) {
120     return CGF.EmitObjCMessageExpr(E).getComplexVal();
121   }
122   ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
123   ComplexPairTy VisitMemberExpr(const Expr *E) { return EmitLoadOfLValue(E); }
124   ComplexPairTy VisitOpaqueValueExpr(OpaqueValueExpr *E) {
125     if (E->isGLValue())
126       return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E));
127     return CGF.getOpaqueRValueMapping(E).getComplexVal();
128   }
129 
130   ComplexPairTy VisitPseudoObjectExpr(PseudoObjectExpr *E) {
131     return CGF.EmitPseudoObjectRValue(E).getComplexVal();
132   }
133 
134   // FIXME: CompoundLiteralExpr
135 
136   ComplexPairTy EmitCast(CastExpr::CastKind CK, Expr *Op, QualType DestTy);
137   ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
138     // Unlike for scalars, we don't have to worry about function->ptr demotion
139     // here.
140     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
141   }
142   ComplexPairTy VisitCastExpr(CastExpr *E) {
143     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
144   }
145   ComplexPairTy VisitCallExpr(const CallExpr *E);
146   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
147 
148   // Operators.
149   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
150                                    bool isInc, bool isPre) {
151     LValue LV = CGF.EmitLValue(E->getSubExpr());
152     return CGF.EmitComplexPrePostIncDec(E, LV, isInc, isPre);
153   }
154   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
155     return VisitPrePostIncDec(E, false, false);
156   }
157   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
158     return VisitPrePostIncDec(E, true, false);
159   }
160   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
161     return VisitPrePostIncDec(E, false, true);
162   }
163   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
164     return VisitPrePostIncDec(E, true, true);
165   }
166   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
167   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
168     TestAndClearIgnoreReal();
169     TestAndClearIgnoreImag();
170     return Visit(E->getSubExpr());
171   }
172   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
173   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
174   // LNot,Real,Imag never return complex.
175   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
176     return Visit(E->getSubExpr());
177   }
178   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
179     return Visit(DAE->getExpr());
180   }
181   ComplexPairTy VisitExprWithCleanups(ExprWithCleanups *E) {
182     CGF.enterFullExpression(E);
183     CodeGenFunction::RunCleanupsScope Scope(CGF);
184     return Visit(E->getSubExpr());
185   }
186   ComplexPairTy VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
187     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
188     QualType Elem = E->getType()->getAs<ComplexType>()->getElementType();
189     llvm::Constant *Null = llvm::Constant::getNullValue(CGF.ConvertType(Elem));
190     return ComplexPairTy(Null, Null);
191   }
192   ComplexPairTy VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
193     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
194     QualType Elem = E->getType()->getAs<ComplexType>()->getElementType();
195     llvm::Constant *Null =
196                        llvm::Constant::getNullValue(CGF.ConvertType(Elem));
197     return ComplexPairTy(Null, Null);
198   }
199 
200   struct BinOpInfo {
201     ComplexPairTy LHS;
202     ComplexPairTy RHS;
203     QualType Ty;  // Computation Type.
204   };
205 
206   BinOpInfo EmitBinOps(const BinaryOperator *E);
207   LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
208                                   ComplexPairTy (ComplexExprEmitter::*Func)
209                                   (const BinOpInfo &),
210                                   ComplexPairTy &Val);
211   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
212                                    ComplexPairTy (ComplexExprEmitter::*Func)
213                                    (const BinOpInfo &));
214 
215   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
216   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
217   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
218   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
219 
220   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
221     return EmitBinAdd(EmitBinOps(E));
222   }
223   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
224     return EmitBinSub(EmitBinOps(E));
225   }
226   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
227     return EmitBinMul(EmitBinOps(E));
228   }
229   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
230     return EmitBinDiv(EmitBinOps(E));
231   }
232 
233   // Compound assignments.
234   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
235     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
236   }
237   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
238     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
239   }
240   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
241     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
242   }
243   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
244     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
245   }
246 
247   // GCC rejects rem/and/or/xor for integer complex.
248   // Logical and/or always return int, never complex.
249 
250   // No comparisons produce a complex result.
251 
252   LValue EmitBinAssignLValue(const BinaryOperator *E,
253                              ComplexPairTy &Val);
254   ComplexPairTy VisitBinAssign     (const BinaryOperator *E);
255   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
256 
257 
258   ComplexPairTy
259   VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
260   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
261 
262   ComplexPairTy VisitInitListExpr(InitListExpr *E);
263 
264   ComplexPairTy VisitVAArgExpr(VAArgExpr *E);
265 
266   ComplexPairTy VisitAtomicExpr(AtomicExpr *E) {
267     return CGF.EmitAtomicExpr(E).getComplexVal();
268   }
269 };
270 }  // end anonymous namespace.
271 
272 //===----------------------------------------------------------------------===//
273 //                                Utilities
274 //===----------------------------------------------------------------------===//
275 
276 /// EmitLoadOfComplex - Given an RValue reference for a complex, emit code to
277 /// load the real and imaginary pieces, returning them as Real/Imag.
278 ComplexPairTy ComplexExprEmitter::EmitLoadOfComplex(llvm::Value *SrcPtr,
279                                                     bool isVolatile) {
280   llvm::Value *Real=0, *Imag=0;
281 
282   if (!IgnoreReal || isVolatile) {
283     llvm::Value *RealP = Builder.CreateStructGEP(SrcPtr, 0,
284                                                  SrcPtr->getName() + ".realp");
285     Real = Builder.CreateLoad(RealP, isVolatile, SrcPtr->getName() + ".real");
286   }
287 
288   if (!IgnoreImag || isVolatile) {
289     llvm::Value *ImagP = Builder.CreateStructGEP(SrcPtr, 1,
290                                                  SrcPtr->getName() + ".imagp");
291     Imag = Builder.CreateLoad(ImagP, isVolatile, SrcPtr->getName() + ".imag");
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   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 ComplexPairTy(llvm::Constant::getNullValue(Imag->getType()), Imag);
325 }
326 
327 
328 ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
329   if (E->getCallReturnType()->isReferenceType())
330     return EmitLoadOfLValue(E);
331 
332   return CGF.EmitCallExpr(E).getComplexVal();
333 }
334 
335 ComplexPairTy ComplexExprEmitter::VisitStmtExpr(const StmtExpr *E) {
336   CodeGenFunction::StmtExprEvaluation eval(CGF);
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(CastExpr::CastKind CK, Expr *Op,
357                                            QualType DestTy) {
358   switch (CK) {
359   case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!");
360 
361   // Atomic to non-atomic casts may be more than a no-op for some platforms and
362   // for some types.
363   case CK_AtomicToNonAtomic:
364   case CK_NonAtomicToAtomic:
365   case CK_NoOp:
366   case CK_LValueToRValue:
367   case CK_UserDefinedConversion:
368     return Visit(Op);
369 
370   case CK_LValueBitCast: {
371     llvm::Value *V = CGF.EmitLValue(Op).getAddress();
372     V = Builder.CreateBitCast(V,
373                     CGF.ConvertType(CGF.getContext().getPointerType(DestTy)));
374     // FIXME: Are the qualifiers correct here?
375     return EmitLoadOfComplex(V, DestTy.isVolatileQualified());
376   }
377 
378   case CK_BitCast:
379   case CK_BaseToDerived:
380   case CK_DerivedToBase:
381   case CK_UncheckedDerivedToBase:
382   case CK_Dynamic:
383   case CK_ToUnion:
384   case CK_ArrayToPointerDecay:
385   case CK_FunctionToPointerDecay:
386   case CK_NullToPointer:
387   case CK_NullToMemberPointer:
388   case CK_BaseToDerivedMemberPointer:
389   case CK_DerivedToBaseMemberPointer:
390   case CK_MemberPointerToBoolean:
391   case CK_ReinterpretMemberPointer:
392   case CK_ConstructorConversion:
393   case CK_IntegralToPointer:
394   case CK_PointerToIntegral:
395   case CK_PointerToBoolean:
396   case CK_ToVoid:
397   case CK_VectorSplat:
398   case CK_IntegralCast:
399   case CK_IntegralToBoolean:
400   case CK_IntegralToFloating:
401   case CK_FloatingToIntegral:
402   case CK_FloatingToBoolean:
403   case CK_FloatingCast:
404   case CK_CPointerToObjCPointerCast:
405   case CK_BlockPointerToObjCPointerCast:
406   case CK_AnyPointerToBlockPointerCast:
407   case CK_ObjCObjectLValueCast:
408   case CK_FloatingComplexToReal:
409   case CK_FloatingComplexToBoolean:
410   case CK_IntegralComplexToReal:
411   case CK_IntegralComplexToBoolean:
412   case CK_ARCProduceObject:
413   case CK_ARCConsumeObject:
414   case CK_ARCReclaimReturnedObject:
415   case CK_ARCExtendBlockObject:
416     llvm_unreachable("invalid cast kind for complex value");
417 
418   case CK_FloatingRealToComplex:
419   case CK_IntegralRealToComplex: {
420     llvm::Value *Elt = CGF.EmitScalarExpr(Op);
421 
422     // Convert the input element to the element type of the complex.
423     DestTy = DestTy->getAs<ComplexType>()->getElementType();
424     Elt = CGF.EmitScalarConversion(Elt, Op->getType(), DestTy);
425 
426     // Return (realval, 0).
427     return ComplexPairTy(Elt, llvm::Constant::getNullValue(Elt->getType()));
428   }
429 
430   case CK_FloatingComplexCast:
431   case CK_FloatingComplexToIntegralComplex:
432   case CK_IntegralComplexCast:
433   case CK_IntegralComplexToFloatingComplex:
434     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
435   }
436 
437   llvm_unreachable("unknown cast resulting in complex value");
438 }
439 
440 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
441   TestAndClearIgnoreReal();
442   TestAndClearIgnoreImag();
443   ComplexPairTy Op = Visit(E->getSubExpr());
444 
445   llvm::Value *ResR, *ResI;
446   if (Op.first->getType()->isFloatingPointTy()) {
447     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
448     ResI = Builder.CreateFNeg(Op.second, "neg.i");
449   } else {
450     ResR = Builder.CreateNeg(Op.first,  "neg.r");
451     ResI = Builder.CreateNeg(Op.second, "neg.i");
452   }
453   return ComplexPairTy(ResR, ResI);
454 }
455 
456 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
457   TestAndClearIgnoreReal();
458   TestAndClearIgnoreImag();
459   // ~(a+ib) = a + i*-b
460   ComplexPairTy Op = Visit(E->getSubExpr());
461   llvm::Value *ResI;
462   if (Op.second->getType()->isFloatingPointTy())
463     ResI = Builder.CreateFNeg(Op.second, "conj.i");
464   else
465     ResI = Builder.CreateNeg(Op.second, "conj.i");
466 
467   return ComplexPairTy(Op.first, ResI);
468 }
469 
470 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
471   llvm::Value *ResR, *ResI;
472 
473   if (Op.LHS.first->getType()->isFloatingPointTy()) {
474     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
475     ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
476   } else {
477     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
478     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
479   }
480   return ComplexPairTy(ResR, ResI);
481 }
482 
483 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
484   llvm::Value *ResR, *ResI;
485   if (Op.LHS.first->getType()->isFloatingPointTy()) {
486     ResR = Builder.CreateFSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
487     ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
488   } else {
489     ResR = Builder.CreateSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
490     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
491   }
492   return ComplexPairTy(ResR, ResI);
493 }
494 
495 
496 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
497   using llvm::Value;
498   Value *ResR, *ResI;
499 
500   if (Op.LHS.first->getType()->isFloatingPointTy()) {
501     Value *ResRl = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
502     Value *ResRr = Builder.CreateFMul(Op.LHS.second, Op.RHS.second,"mul.rr");
503     ResR  = Builder.CreateFSub(ResRl, ResRr, "mul.r");
504 
505     Value *ResIl = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il");
506     Value *ResIr = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
507     ResI  = Builder.CreateFAdd(ResIl, ResIr, "mul.i");
508   } else {
509     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
510     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
511     ResR  = Builder.CreateSub(ResRl, ResRr, "mul.r");
512 
513     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
514     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
515     ResI  = Builder.CreateAdd(ResIl, ResIr, "mul.i");
516   }
517   return ComplexPairTy(ResR, ResI);
518 }
519 
520 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
521   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
522   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
523 
524 
525   llvm::Value *DSTr, *DSTi;
526   if (Op.LHS.first->getType()->isFloatingPointTy()) {
527     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
528     llvm::Value *Tmp1 = Builder.CreateFMul(LHSr, RHSr); // a*c
529     llvm::Value *Tmp2 = Builder.CreateFMul(LHSi, RHSi); // b*d
530     llvm::Value *Tmp3 = Builder.CreateFAdd(Tmp1, Tmp2); // ac+bd
531 
532     llvm::Value *Tmp4 = Builder.CreateFMul(RHSr, RHSr); // c*c
533     llvm::Value *Tmp5 = Builder.CreateFMul(RHSi, RHSi); // d*d
534     llvm::Value *Tmp6 = Builder.CreateFAdd(Tmp4, Tmp5); // cc+dd
535 
536     llvm::Value *Tmp7 = Builder.CreateFMul(LHSi, RHSr); // b*c
537     llvm::Value *Tmp8 = Builder.CreateFMul(LHSr, RHSi); // a*d
538     llvm::Value *Tmp9 = Builder.CreateFSub(Tmp7, Tmp8); // bc-ad
539 
540     DSTr = Builder.CreateFDiv(Tmp3, Tmp6);
541     DSTi = Builder.CreateFDiv(Tmp9, Tmp6);
542   } else {
543     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
544     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr); // a*c
545     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi); // b*d
546     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2); // ac+bd
547 
548     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr); // c*c
549     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi); // d*d
550     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5); // cc+dd
551 
552     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr); // b*c
553     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi); // a*d
554     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8); // bc-ad
555 
556     if (Op.Ty->getAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
557       DSTr = Builder.CreateUDiv(Tmp3, Tmp6);
558       DSTi = Builder.CreateUDiv(Tmp9, Tmp6);
559     } else {
560       DSTr = Builder.CreateSDiv(Tmp3, Tmp6);
561       DSTi = Builder.CreateSDiv(Tmp9, Tmp6);
562     }
563   }
564 
565   return ComplexPairTy(DSTr, DSTi);
566 }
567 
568 ComplexExprEmitter::BinOpInfo
569 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
570   TestAndClearIgnoreReal();
571   TestAndClearIgnoreImag();
572   BinOpInfo Ops;
573   Ops.LHS = Visit(E->getLHS());
574   Ops.RHS = Visit(E->getRHS());
575   Ops.Ty = E->getType();
576   return Ops;
577 }
578 
579 
580 LValue ComplexExprEmitter::
581 EmitCompoundAssignLValue(const CompoundAssignOperator *E,
582           ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&),
583                          ComplexPairTy &Val) {
584   TestAndClearIgnoreReal();
585   TestAndClearIgnoreImag();
586   QualType LHSTy = E->getLHS()->getType();
587 
588   BinOpInfo OpInfo;
589 
590   // Load the RHS and LHS operands.
591   // __block variables need to have the rhs evaluated first, plus this should
592   // improve codegen a little.
593   OpInfo.Ty = E->getComputationResultType();
594 
595   // The RHS should have been converted to the computation type.
596   assert(OpInfo.Ty->isAnyComplexType());
597   assert(CGF.getContext().hasSameUnqualifiedType(OpInfo.Ty,
598                                                  E->getRHS()->getType()));
599   OpInfo.RHS = Visit(E->getRHS());
600 
601   LValue LHS = CGF.EmitLValue(E->getLHS());
602 
603   // Load from the l-value.
604   ComplexPairTy LHSComplexPair = EmitLoadOfLValue(LHS);
605 
606   OpInfo.LHS = EmitComplexToComplexCast(LHSComplexPair, LHSTy, OpInfo.Ty);
607 
608   // Expand the binary operator.
609   ComplexPairTy Result = (this->*Func)(OpInfo);
610 
611   // Truncate the result back to the LHS type.
612   Result = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
613   Val = Result;
614 
615   // Store the result value into the LHS lvalue.
616   EmitStoreThroughLValue(Result, LHS);
617 
618   return LHS;
619 }
620 
621 // Compound assignments.
622 ComplexPairTy ComplexExprEmitter::
623 EmitCompoundAssign(const CompoundAssignOperator *E,
624                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
625   ComplexPairTy Val;
626   LValue LV = EmitCompoundAssignLValue(E, Func, Val);
627 
628   // The result of an assignment in C is the assigned r-value.
629   if (!CGF.getContext().getLangOptions().CPlusPlus)
630     return Val;
631 
632   // If the lvalue is non-volatile, return the computed value of the assignment.
633   if (!LV.isVolatileQualified())
634     return Val;
635 
636   return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
637 }
638 
639 LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
640                                                ComplexPairTy &Val) {
641   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
642                                                  E->getRHS()->getType()) &&
643          "Invalid assignment");
644   TestAndClearIgnoreReal();
645   TestAndClearIgnoreImag();
646 
647   // Emit the RHS.  __block variables need the RHS evaluated first.
648   Val = Visit(E->getRHS());
649 
650   // Compute the address to store into.
651   LValue LHS = CGF.EmitLValue(E->getLHS());
652 
653   // Store the result value into the LHS lvalue.
654   EmitStoreThroughLValue(Val, LHS);
655 
656   return LHS;
657 }
658 
659 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
660   ComplexPairTy Val;
661   LValue LV = EmitBinAssignLValue(E, Val);
662 
663   // The result of an assignment in C is the assigned r-value.
664   if (!CGF.getContext().getLangOptions().CPlusPlus)
665     return Val;
666 
667   // If the lvalue is non-volatile, return the computed value of the assignment.
668   if (!LV.isVolatileQualified())
669     return Val;
670 
671   return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
672 }
673 
674 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
675   CGF.EmitIgnoredExpr(E->getLHS());
676   return Visit(E->getRHS());
677 }
678 
679 ComplexPairTy ComplexExprEmitter::
680 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
681   TestAndClearIgnoreReal();
682   TestAndClearIgnoreImag();
683   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
684   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
685   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
686 
687   // Bind the common expression if necessary.
688   CodeGenFunction::OpaqueValueMapping binding(CGF, E);
689 
690   CodeGenFunction::ConditionalEvaluation eval(CGF);
691   CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
692 
693   eval.begin(CGF);
694   CGF.EmitBlock(LHSBlock);
695   ComplexPairTy LHS = Visit(E->getTrueExpr());
696   LHSBlock = Builder.GetInsertBlock();
697   CGF.EmitBranch(ContBlock);
698   eval.end(CGF);
699 
700   eval.begin(CGF);
701   CGF.EmitBlock(RHSBlock);
702   ComplexPairTy RHS = Visit(E->getFalseExpr());
703   RHSBlock = Builder.GetInsertBlock();
704   CGF.EmitBlock(ContBlock);
705   eval.end(CGF);
706 
707   // Create a PHI node for the real part.
708   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.r");
709   RealPN->addIncoming(LHS.first, LHSBlock);
710   RealPN->addIncoming(RHS.first, RHSBlock);
711 
712   // Create a PHI node for the imaginary part.
713   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.i");
714   ImagPN->addIncoming(LHS.second, LHSBlock);
715   ImagPN->addIncoming(RHS.second, RHSBlock);
716 
717   return ComplexPairTy(RealPN, ImagPN);
718 }
719 
720 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
721   return Visit(E->getChosenSubExpr(CGF.getContext()));
722 }
723 
724 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
725     bool Ignore = TestAndClearIgnoreReal();
726     (void)Ignore;
727     assert (Ignore == false && "init list ignored");
728     Ignore = TestAndClearIgnoreImag();
729     (void)Ignore;
730     assert (Ignore == false && "init list ignored");
731 
732   if (E->getNumInits() == 2) {
733     llvm::Value *Real = CGF.EmitScalarExpr(E->getInit(0));
734     llvm::Value *Imag = CGF.EmitScalarExpr(E->getInit(1));
735     return ComplexPairTy(Real, Imag);
736   } else if (E->getNumInits() == 1) {
737     return Visit(E->getInit(0));
738   }
739 
740   // Empty init list intializes to null
741   assert(E->getNumInits() == 0 && "Unexpected number of inits");
742   QualType Ty = E->getType()->getAs<ComplexType>()->getElementType();
743   llvm::Type* LTy = CGF.ConvertType(Ty);
744   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
745   return ComplexPairTy(zeroConstant, zeroConstant);
746 }
747 
748 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
749   llvm::Value *ArgValue = CGF.EmitVAListRef(E->getSubExpr());
750   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, E->getType());
751 
752   if (!ArgPtr) {
753     CGF.ErrorUnsupported(E, "complex va_arg expression");
754     llvm::Type *EltTy =
755       CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
756     llvm::Value *U = llvm::UndefValue::get(EltTy);
757     return ComplexPairTy(U, U);
758   }
759 
760   // FIXME Volatility.
761   return EmitLoadOfComplex(ArgPtr, false);
762 }
763 
764 //===----------------------------------------------------------------------===//
765 //                         Entry Point into this File
766 //===----------------------------------------------------------------------===//
767 
768 /// EmitComplexExpr - Emit the computation of the specified expression of
769 /// complex type, ignoring the result.
770 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
771                                                bool IgnoreImag) {
772   assert(E && E->getType()->isAnyComplexType() &&
773          "Invalid complex expression to emit");
774 
775   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag)
776     .Visit(const_cast<Expr*>(E));
777 }
778 
779 /// EmitComplexExprIntoAddr - Emit the computation of the specified expression
780 /// of complex type, storing into the specified Value*.
781 void CodeGenFunction::EmitComplexExprIntoAddr(const Expr *E,
782                                               llvm::Value *DestAddr,
783                                               bool DestIsVolatile) {
784   assert(E && E->getType()->isAnyComplexType() &&
785          "Invalid complex expression to emit");
786   ComplexExprEmitter Emitter(*this);
787   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
788   Emitter.EmitStoreOfComplex(Val, DestAddr, DestIsVolatile);
789 }
790 
791 /// StoreComplexToAddr - Store a complex number into the specified address.
792 void CodeGenFunction::StoreComplexToAddr(ComplexPairTy V,
793                                          llvm::Value *DestAddr,
794                                          bool DestIsVolatile) {
795   ComplexExprEmitter(*this).EmitStoreOfComplex(V, DestAddr, DestIsVolatile);
796 }
797 
798 /// LoadComplexFromAddr - Load a complex number from the specified address.
799 ComplexPairTy CodeGenFunction::LoadComplexFromAddr(llvm::Value *SrcAddr,
800                                                    bool SrcIsVolatile) {
801   return ComplexExprEmitter(*this).EmitLoadOfComplex(SrcAddr, SrcIsVolatile);
802 }
803 
804 LValue CodeGenFunction::EmitComplexAssignmentLValue(const BinaryOperator *E) {
805   assert(E->getOpcode() == BO_Assign);
806   ComplexPairTy Val; // ignored
807   return ComplexExprEmitter(*this).EmitBinAssignLValue(E, Val);
808 }
809 
810 LValue CodeGenFunction::
811 EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E) {
812   ComplexPairTy(ComplexExprEmitter::*Op)(const ComplexExprEmitter::BinOpInfo &);
813   switch (E->getOpcode()) {
814   case BO_MulAssign: Op = &ComplexExprEmitter::EmitBinMul; break;
815   case BO_DivAssign: Op = &ComplexExprEmitter::EmitBinDiv; break;
816   case BO_SubAssign: Op = &ComplexExprEmitter::EmitBinSub; break;
817   case BO_AddAssign: Op = &ComplexExprEmitter::EmitBinAdd; break;
818 
819   default:
820     llvm_unreachable("unexpected complex compound assignment");
821   }
822 
823   ComplexPairTy Val; // ignored
824   return ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
825 }
826