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   case CK_CopyAndAutoreleaseBlockObject:
417     llvm_unreachable("invalid cast kind for complex value");
418 
419   case CK_FloatingRealToComplex:
420   case CK_IntegralRealToComplex: {
421     llvm::Value *Elt = CGF.EmitScalarExpr(Op);
422 
423     // Convert the input element to the element type of the complex.
424     DestTy = DestTy->getAs<ComplexType>()->getElementType();
425     Elt = CGF.EmitScalarConversion(Elt, Op->getType(), DestTy);
426 
427     // Return (realval, 0).
428     return ComplexPairTy(Elt, llvm::Constant::getNullValue(Elt->getType()));
429   }
430 
431   case CK_FloatingComplexCast:
432   case CK_FloatingComplexToIntegralComplex:
433   case CK_IntegralComplexCast:
434   case CK_IntegralComplexToFloatingComplex:
435     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
436   }
437 
438   llvm_unreachable("unknown cast resulting in complex value");
439 }
440 
441 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
442   TestAndClearIgnoreReal();
443   TestAndClearIgnoreImag();
444   ComplexPairTy Op = Visit(E->getSubExpr());
445 
446   llvm::Value *ResR, *ResI;
447   if (Op.first->getType()->isFloatingPointTy()) {
448     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
449     ResI = Builder.CreateFNeg(Op.second, "neg.i");
450   } else {
451     ResR = Builder.CreateNeg(Op.first,  "neg.r");
452     ResI = Builder.CreateNeg(Op.second, "neg.i");
453   }
454   return ComplexPairTy(ResR, ResI);
455 }
456 
457 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
458   TestAndClearIgnoreReal();
459   TestAndClearIgnoreImag();
460   // ~(a+ib) = a + i*-b
461   ComplexPairTy Op = Visit(E->getSubExpr());
462   llvm::Value *ResI;
463   if (Op.second->getType()->isFloatingPointTy())
464     ResI = Builder.CreateFNeg(Op.second, "conj.i");
465   else
466     ResI = Builder.CreateNeg(Op.second, "conj.i");
467 
468   return ComplexPairTy(Op.first, ResI);
469 }
470 
471 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
472   llvm::Value *ResR, *ResI;
473 
474   if (Op.LHS.first->getType()->isFloatingPointTy()) {
475     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
476     ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
477   } else {
478     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
479     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
480   }
481   return ComplexPairTy(ResR, ResI);
482 }
483 
484 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
485   llvm::Value *ResR, *ResI;
486   if (Op.LHS.first->getType()->isFloatingPointTy()) {
487     ResR = Builder.CreateFSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
488     ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
489   } else {
490     ResR = Builder.CreateSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
491     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
492   }
493   return ComplexPairTy(ResR, ResI);
494 }
495 
496 
497 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
498   using llvm::Value;
499   Value *ResR, *ResI;
500 
501   if (Op.LHS.first->getType()->isFloatingPointTy()) {
502     Value *ResRl = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
503     Value *ResRr = Builder.CreateFMul(Op.LHS.second, Op.RHS.second,"mul.rr");
504     ResR  = Builder.CreateFSub(ResRl, ResRr, "mul.r");
505 
506     Value *ResIl = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il");
507     Value *ResIr = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
508     ResI  = Builder.CreateFAdd(ResIl, ResIr, "mul.i");
509   } else {
510     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
511     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
512     ResR  = Builder.CreateSub(ResRl, ResRr, "mul.r");
513 
514     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
515     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
516     ResI  = Builder.CreateAdd(ResIl, ResIr, "mul.i");
517   }
518   return ComplexPairTy(ResR, ResI);
519 }
520 
521 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
522   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
523   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
524 
525 
526   llvm::Value *DSTr, *DSTi;
527   if (Op.LHS.first->getType()->isFloatingPointTy()) {
528     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
529     llvm::Value *Tmp1 = Builder.CreateFMul(LHSr, RHSr); // a*c
530     llvm::Value *Tmp2 = Builder.CreateFMul(LHSi, RHSi); // b*d
531     llvm::Value *Tmp3 = Builder.CreateFAdd(Tmp1, Tmp2); // ac+bd
532 
533     llvm::Value *Tmp4 = Builder.CreateFMul(RHSr, RHSr); // c*c
534     llvm::Value *Tmp5 = Builder.CreateFMul(RHSi, RHSi); // d*d
535     llvm::Value *Tmp6 = Builder.CreateFAdd(Tmp4, Tmp5); // cc+dd
536 
537     llvm::Value *Tmp7 = Builder.CreateFMul(LHSi, RHSr); // b*c
538     llvm::Value *Tmp8 = Builder.CreateFMul(LHSr, RHSi); // a*d
539     llvm::Value *Tmp9 = Builder.CreateFSub(Tmp7, Tmp8); // bc-ad
540 
541     DSTr = Builder.CreateFDiv(Tmp3, Tmp6);
542     DSTi = Builder.CreateFDiv(Tmp9, Tmp6);
543   } else {
544     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
545     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr); // a*c
546     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi); // b*d
547     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2); // ac+bd
548 
549     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr); // c*c
550     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi); // d*d
551     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5); // cc+dd
552 
553     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr); // b*c
554     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi); // a*d
555     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8); // bc-ad
556 
557     if (Op.Ty->getAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
558       DSTr = Builder.CreateUDiv(Tmp3, Tmp6);
559       DSTi = Builder.CreateUDiv(Tmp9, Tmp6);
560     } else {
561       DSTr = Builder.CreateSDiv(Tmp3, Tmp6);
562       DSTi = Builder.CreateSDiv(Tmp9, Tmp6);
563     }
564   }
565 
566   return ComplexPairTy(DSTr, DSTi);
567 }
568 
569 ComplexExprEmitter::BinOpInfo
570 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
571   TestAndClearIgnoreReal();
572   TestAndClearIgnoreImag();
573   BinOpInfo Ops;
574   Ops.LHS = Visit(E->getLHS());
575   Ops.RHS = Visit(E->getRHS());
576   Ops.Ty = E->getType();
577   return Ops;
578 }
579 
580 
581 LValue ComplexExprEmitter::
582 EmitCompoundAssignLValue(const CompoundAssignOperator *E,
583           ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&),
584                          ComplexPairTy &Val) {
585   TestAndClearIgnoreReal();
586   TestAndClearIgnoreImag();
587   QualType LHSTy = E->getLHS()->getType();
588 
589   BinOpInfo OpInfo;
590 
591   // Load the RHS and LHS operands.
592   // __block variables need to have the rhs evaluated first, plus this should
593   // improve codegen a little.
594   OpInfo.Ty = E->getComputationResultType();
595 
596   // The RHS should have been converted to the computation type.
597   assert(OpInfo.Ty->isAnyComplexType());
598   assert(CGF.getContext().hasSameUnqualifiedType(OpInfo.Ty,
599                                                  E->getRHS()->getType()));
600   OpInfo.RHS = Visit(E->getRHS());
601 
602   LValue LHS = CGF.EmitLValue(E->getLHS());
603 
604   // Load from the l-value.
605   ComplexPairTy LHSComplexPair = EmitLoadOfLValue(LHS);
606 
607   OpInfo.LHS = EmitComplexToComplexCast(LHSComplexPair, LHSTy, OpInfo.Ty);
608 
609   // Expand the binary operator.
610   ComplexPairTy Result = (this->*Func)(OpInfo);
611 
612   // Truncate the result back to the LHS type.
613   Result = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
614   Val = Result;
615 
616   // Store the result value into the LHS lvalue.
617   EmitStoreThroughLValue(Result, LHS);
618 
619   return LHS;
620 }
621 
622 // Compound assignments.
623 ComplexPairTy ComplexExprEmitter::
624 EmitCompoundAssign(const CompoundAssignOperator *E,
625                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
626   ComplexPairTy Val;
627   LValue LV = EmitCompoundAssignLValue(E, Func, Val);
628 
629   // The result of an assignment in C is the assigned r-value.
630   if (!CGF.getContext().getLangOptions().CPlusPlus)
631     return Val;
632 
633   // If the lvalue is non-volatile, return the computed value of the assignment.
634   if (!LV.isVolatileQualified())
635     return Val;
636 
637   return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
638 }
639 
640 LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
641                                                ComplexPairTy &Val) {
642   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
643                                                  E->getRHS()->getType()) &&
644          "Invalid assignment");
645   TestAndClearIgnoreReal();
646   TestAndClearIgnoreImag();
647 
648   // Emit the RHS.  __block variables need the RHS evaluated first.
649   Val = Visit(E->getRHS());
650 
651   // Compute the address to store into.
652   LValue LHS = CGF.EmitLValue(E->getLHS());
653 
654   // Store the result value into the LHS lvalue.
655   EmitStoreThroughLValue(Val, LHS);
656 
657   return LHS;
658 }
659 
660 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
661   ComplexPairTy Val;
662   LValue LV = EmitBinAssignLValue(E, Val);
663 
664   // The result of an assignment in C is the assigned r-value.
665   if (!CGF.getContext().getLangOptions().CPlusPlus)
666     return Val;
667 
668   // If the lvalue is non-volatile, return the computed value of the assignment.
669   if (!LV.isVolatileQualified())
670     return Val;
671 
672   return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
673 }
674 
675 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
676   CGF.EmitIgnoredExpr(E->getLHS());
677   return Visit(E->getRHS());
678 }
679 
680 ComplexPairTy ComplexExprEmitter::
681 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
682   TestAndClearIgnoreReal();
683   TestAndClearIgnoreImag();
684   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
685   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
686   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
687 
688   // Bind the common expression if necessary.
689   CodeGenFunction::OpaqueValueMapping binding(CGF, E);
690 
691   CodeGenFunction::ConditionalEvaluation eval(CGF);
692   CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
693 
694   eval.begin(CGF);
695   CGF.EmitBlock(LHSBlock);
696   ComplexPairTy LHS = Visit(E->getTrueExpr());
697   LHSBlock = Builder.GetInsertBlock();
698   CGF.EmitBranch(ContBlock);
699   eval.end(CGF);
700 
701   eval.begin(CGF);
702   CGF.EmitBlock(RHSBlock);
703   ComplexPairTy RHS = Visit(E->getFalseExpr());
704   RHSBlock = Builder.GetInsertBlock();
705   CGF.EmitBlock(ContBlock);
706   eval.end(CGF);
707 
708   // Create a PHI node for the real part.
709   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.r");
710   RealPN->addIncoming(LHS.first, LHSBlock);
711   RealPN->addIncoming(RHS.first, RHSBlock);
712 
713   // Create a PHI node for the imaginary part.
714   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.i");
715   ImagPN->addIncoming(LHS.second, LHSBlock);
716   ImagPN->addIncoming(RHS.second, RHSBlock);
717 
718   return ComplexPairTy(RealPN, ImagPN);
719 }
720 
721 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
722   return Visit(E->getChosenSubExpr(CGF.getContext()));
723 }
724 
725 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
726     bool Ignore = TestAndClearIgnoreReal();
727     (void)Ignore;
728     assert (Ignore == false && "init list ignored");
729     Ignore = TestAndClearIgnoreImag();
730     (void)Ignore;
731     assert (Ignore == false && "init list ignored");
732 
733   if (E->getNumInits() == 2) {
734     llvm::Value *Real = CGF.EmitScalarExpr(E->getInit(0));
735     llvm::Value *Imag = CGF.EmitScalarExpr(E->getInit(1));
736     return ComplexPairTy(Real, Imag);
737   } else if (E->getNumInits() == 1) {
738     return Visit(E->getInit(0));
739   }
740 
741   // Empty init list intializes to null
742   assert(E->getNumInits() == 0 && "Unexpected number of inits");
743   QualType Ty = E->getType()->getAs<ComplexType>()->getElementType();
744   llvm::Type* LTy = CGF.ConvertType(Ty);
745   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
746   return ComplexPairTy(zeroConstant, zeroConstant);
747 }
748 
749 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
750   llvm::Value *ArgValue = CGF.EmitVAListRef(E->getSubExpr());
751   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, E->getType());
752 
753   if (!ArgPtr) {
754     CGF.ErrorUnsupported(E, "complex va_arg expression");
755     llvm::Type *EltTy =
756       CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
757     llvm::Value *U = llvm::UndefValue::get(EltTy);
758     return ComplexPairTy(U, U);
759   }
760 
761   // FIXME Volatility.
762   return EmitLoadOfComplex(ArgPtr, false);
763 }
764 
765 //===----------------------------------------------------------------------===//
766 //                         Entry Point into this File
767 //===----------------------------------------------------------------------===//
768 
769 /// EmitComplexExpr - Emit the computation of the specified expression of
770 /// complex type, ignoring the result.
771 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
772                                                bool IgnoreImag) {
773   assert(E && E->getType()->isAnyComplexType() &&
774          "Invalid complex expression to emit");
775 
776   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag)
777     .Visit(const_cast<Expr*>(E));
778 }
779 
780 /// EmitComplexExprIntoAddr - Emit the computation of the specified expression
781 /// of complex type, storing into the specified Value*.
782 void CodeGenFunction::EmitComplexExprIntoAddr(const Expr *E,
783                                               llvm::Value *DestAddr,
784                                               bool DestIsVolatile) {
785   assert(E && E->getType()->isAnyComplexType() &&
786          "Invalid complex expression to emit");
787   ComplexExprEmitter Emitter(*this);
788   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
789   Emitter.EmitStoreOfComplex(Val, DestAddr, DestIsVolatile);
790 }
791 
792 /// StoreComplexToAddr - Store a complex number into the specified address.
793 void CodeGenFunction::StoreComplexToAddr(ComplexPairTy V,
794                                          llvm::Value *DestAddr,
795                                          bool DestIsVolatile) {
796   ComplexExprEmitter(*this).EmitStoreOfComplex(V, DestAddr, DestIsVolatile);
797 }
798 
799 /// LoadComplexFromAddr - Load a complex number from the specified address.
800 ComplexPairTy CodeGenFunction::LoadComplexFromAddr(llvm::Value *SrcAddr,
801                                                    bool SrcIsVolatile) {
802   return ComplexExprEmitter(*this).EmitLoadOfComplex(SrcAddr, SrcIsVolatile);
803 }
804 
805 LValue CodeGenFunction::EmitComplexAssignmentLValue(const BinaryOperator *E) {
806   assert(E->getOpcode() == BO_Assign);
807   ComplexPairTy Val; // ignored
808   return ComplexExprEmitter(*this).EmitBinAssignLValue(E, Val);
809 }
810 
811 LValue CodeGenFunction::
812 EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E) {
813   ComplexPairTy(ComplexExprEmitter::*Op)(const ComplexExprEmitter::BinOpInfo &);
814   switch (E->getOpcode()) {
815   case BO_MulAssign: Op = &ComplexExprEmitter::EmitBinMul; break;
816   case BO_DivAssign: Op = &ComplexExprEmitter::EmitBinDiv; break;
817   case BO_SubAssign: Op = &ComplexExprEmitter::EmitBinSub; break;
818   case BO_AddAssign: Op = &ComplexExprEmitter::EmitBinAdd; break;
819 
820   default:
821     llvm_unreachable("unexpected complex compound assignment");
822   }
823 
824   ComplexPairTy Val; // ignored
825   return ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
826 }
827