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/ADT/SmallString.h"
19 #include "llvm/IR/Constants.h"
20 #include "llvm/IR/Function.h"
21 using namespace clang;
22 using namespace CodeGen;
23 
24 //===----------------------------------------------------------------------===//
25 //                        Complex Expression Emitter
26 //===----------------------------------------------------------------------===//
27 
28 typedef CodeGenFunction::ComplexPairTy ComplexPairTy;
29 
30 /// Return the complex type that we are meant to emit.
31 static const ComplexType *getComplexType(QualType type) {
32   type = type.getCanonicalType();
33   if (const ComplexType *comp = dyn_cast<ComplexType>(type)) {
34     return comp;
35   } else {
36     return cast<ComplexType>(cast<AtomicType>(type)->getValueType());
37   }
38 }
39 
40 namespace  {
41 class ComplexExprEmitter
42   : public StmtVisitor<ComplexExprEmitter, ComplexPairTy> {
43   CodeGenFunction &CGF;
44   CGBuilderTy &Builder;
45   // True is we should ignore the value of a
46   bool IgnoreReal;
47   bool IgnoreImag;
48 public:
49   ComplexExprEmitter(CodeGenFunction &cgf, bool ir=false, bool ii=false)
50     : CGF(cgf), Builder(CGF.Builder), IgnoreReal(ir), IgnoreImag(ii) {
51   }
52 
53 
54   //===--------------------------------------------------------------------===//
55   //                               Utilities
56   //===--------------------------------------------------------------------===//
57 
58   bool TestAndClearIgnoreReal() {
59     bool I = IgnoreReal;
60     IgnoreReal = false;
61     return I;
62   }
63   bool TestAndClearIgnoreImag() {
64     bool I = IgnoreImag;
65     IgnoreImag = false;
66     return I;
67   }
68 
69   /// EmitLoadOfLValue - Given an expression with complex type that represents a
70   /// value l-value, this method emits the address of the l-value, then loads
71   /// and returns the result.
72   ComplexPairTy EmitLoadOfLValue(const Expr *E) {
73     return EmitLoadOfLValue(CGF.EmitLValue(E));
74   }
75 
76   ComplexPairTy EmitLoadOfLValue(LValue LV);
77 
78   /// EmitStoreOfComplex - Store the specified real/imag parts into the
79   /// specified value pointer.
80   void EmitStoreOfComplex(ComplexPairTy Val, LValue LV, bool isInit);
81 
82   /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
83   ComplexPairTy EmitComplexToComplexCast(ComplexPairTy Val, QualType SrcType,
84                                          QualType DestType);
85 
86   //===--------------------------------------------------------------------===//
87   //                            Visitor Methods
88   //===--------------------------------------------------------------------===//
89 
90   ComplexPairTy Visit(Expr *E) {
91     return StmtVisitor<ComplexExprEmitter, ComplexPairTy>::Visit(E);
92   }
93 
94   ComplexPairTy VisitStmt(Stmt *S) {
95     S->dump(CGF.getContext().getSourceManager());
96     llvm_unreachable("Stmt can't have complex result type!");
97   }
98   ComplexPairTy VisitExpr(Expr *S);
99   ComplexPairTy VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr());}
100   ComplexPairTy VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
101     return Visit(GE->getResultExpr());
102   }
103   ComplexPairTy VisitImaginaryLiteral(const ImaginaryLiteral *IL);
104   ComplexPairTy
105   VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *PE) {
106     return Visit(PE->getReplacement());
107   }
108 
109   // l-values.
110   ComplexPairTy VisitDeclRefExpr(DeclRefExpr *E) {
111     if (CodeGenFunction::ConstantEmission result = CGF.tryEmitAsConstant(E)) {
112       if (result.isReference())
113         return EmitLoadOfLValue(result.getReferenceLValue(CGF, E));
114 
115       llvm::ConstantStruct *pair =
116         cast<llvm::ConstantStruct>(result.getValue());
117       return ComplexPairTy(pair->getOperand(0), pair->getOperand(1));
118     }
119     return EmitLoadOfLValue(E);
120   }
121   ComplexPairTy VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
122     return EmitLoadOfLValue(E);
123   }
124   ComplexPairTy VisitObjCMessageExpr(ObjCMessageExpr *E) {
125     return CGF.EmitObjCMessageExpr(E).getComplexVal();
126   }
127   ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
128   ComplexPairTy VisitMemberExpr(const Expr *E) { return EmitLoadOfLValue(E); }
129   ComplexPairTy VisitOpaqueValueExpr(OpaqueValueExpr *E) {
130     if (E->isGLValue())
131       return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E));
132     return CGF.getOpaqueRValueMapping(E).getComplexVal();
133   }
134 
135   ComplexPairTy VisitPseudoObjectExpr(PseudoObjectExpr *E) {
136     return CGF.EmitPseudoObjectRValue(E).getComplexVal();
137   }
138 
139   // FIXME: CompoundLiteralExpr
140 
141   ComplexPairTy EmitCast(CastExpr::CastKind CK, Expr *Op, QualType DestTy);
142   ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
143     // Unlike for scalars, we don't have to worry about function->ptr demotion
144     // here.
145     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
146   }
147   ComplexPairTy VisitCastExpr(CastExpr *E) {
148     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
149   }
150   ComplexPairTy VisitCallExpr(const CallExpr *E);
151   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
152 
153   // Operators.
154   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
155                                    bool isInc, bool isPre) {
156     LValue LV = CGF.EmitLValue(E->getSubExpr());
157     return CGF.EmitComplexPrePostIncDec(E, LV, isInc, isPre);
158   }
159   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
160     return VisitPrePostIncDec(E, false, false);
161   }
162   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
163     return VisitPrePostIncDec(E, true, false);
164   }
165   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
166     return VisitPrePostIncDec(E, false, true);
167   }
168   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
169     return VisitPrePostIncDec(E, true, true);
170   }
171   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
172   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
173     TestAndClearIgnoreReal();
174     TestAndClearIgnoreImag();
175     return Visit(E->getSubExpr());
176   }
177   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
178   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
179   // LNot,Real,Imag never return complex.
180   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
181     return Visit(E->getSubExpr());
182   }
183   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
184     return Visit(DAE->getExpr());
185   }
186   ComplexPairTy VisitExprWithCleanups(ExprWithCleanups *E) {
187     CGF.enterFullExpression(E);
188     CodeGenFunction::RunCleanupsScope Scope(CGF);
189     return Visit(E->getSubExpr());
190   }
191   ComplexPairTy VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
192     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
193     QualType Elem = E->getType()->castAs<ComplexType>()->getElementType();
194     llvm::Constant *Null = llvm::Constant::getNullValue(CGF.ConvertType(Elem));
195     return ComplexPairTy(Null, Null);
196   }
197   ComplexPairTy VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
198     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
199     QualType Elem = E->getType()->castAs<ComplexType>()->getElementType();
200     llvm::Constant *Null =
201                        llvm::Constant::getNullValue(CGF.ConvertType(Elem));
202     return ComplexPairTy(Null, Null);
203   }
204 
205   struct BinOpInfo {
206     ComplexPairTy LHS;
207     ComplexPairTy RHS;
208     QualType Ty;  // Computation Type.
209   };
210 
211   BinOpInfo EmitBinOps(const BinaryOperator *E);
212   LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
213                                   ComplexPairTy (ComplexExprEmitter::*Func)
214                                   (const BinOpInfo &),
215                                   ComplexPairTy &Val);
216   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
217                                    ComplexPairTy (ComplexExprEmitter::*Func)
218                                    (const BinOpInfo &));
219 
220   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
221   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
222   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
223   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
224 
225   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
226     return EmitBinAdd(EmitBinOps(E));
227   }
228   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
229     return EmitBinSub(EmitBinOps(E));
230   }
231   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
232     return EmitBinMul(EmitBinOps(E));
233   }
234   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
235     return EmitBinDiv(EmitBinOps(E));
236   }
237 
238   // Compound assignments.
239   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
240     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
241   }
242   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
243     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
244   }
245   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
246     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
247   }
248   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
249     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
250   }
251 
252   // GCC rejects rem/and/or/xor for integer complex.
253   // Logical and/or always return int, never complex.
254 
255   // No comparisons produce a complex result.
256 
257   LValue EmitBinAssignLValue(const BinaryOperator *E,
258                              ComplexPairTy &Val);
259   ComplexPairTy VisitBinAssign     (const BinaryOperator *E);
260   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
261 
262 
263   ComplexPairTy
264   VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
265   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
266 
267   ComplexPairTy VisitInitListExpr(InitListExpr *E);
268 
269   ComplexPairTy VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
270     return EmitLoadOfLValue(E);
271   }
272 
273   ComplexPairTy VisitVAArgExpr(VAArgExpr *E);
274 
275   ComplexPairTy VisitAtomicExpr(AtomicExpr *E) {
276     return CGF.EmitAtomicExpr(E).getComplexVal();
277   }
278 };
279 }  // end anonymous namespace.
280 
281 //===----------------------------------------------------------------------===//
282 //                                Utilities
283 //===----------------------------------------------------------------------===//
284 
285 /// EmitLoadOfLValue - Given an RValue reference for a complex, emit code to
286 /// load the real and imaginary pieces, returning them as Real/Imag.
287 ComplexPairTy ComplexExprEmitter::EmitLoadOfLValue(LValue lvalue) {
288   assert(lvalue.isSimple() && "non-simple complex l-value?");
289   llvm::Value *SrcPtr = lvalue.getAddress();
290   bool isVolatile = lvalue.isVolatileQualified();
291 
292   llvm::Value *Real=0, *Imag=0;
293 
294   if (!IgnoreReal || isVolatile) {
295     llvm::Value *RealP = Builder.CreateStructGEP(SrcPtr, 0,
296                                                  SrcPtr->getName() + ".realp");
297     Real = Builder.CreateLoad(RealP, isVolatile, SrcPtr->getName() + ".real");
298   }
299 
300   if (!IgnoreImag || isVolatile) {
301     llvm::Value *ImagP = Builder.CreateStructGEP(SrcPtr, 1,
302                                                  SrcPtr->getName() + ".imagp");
303     Imag = Builder.CreateLoad(ImagP, isVolatile, SrcPtr->getName() + ".imag");
304   }
305   return ComplexPairTy(Real, Imag);
306 }
307 
308 /// EmitStoreOfComplex - Store the specified real/imag parts into the
309 /// specified value pointer.
310 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val,
311                                             LValue lvalue,
312                                             bool isInit) {
313   llvm::Value *Ptr = lvalue.getAddress();
314   llvm::Value *RealPtr = Builder.CreateStructGEP(Ptr, 0, "real");
315   llvm::Value *ImagPtr = Builder.CreateStructGEP(Ptr, 1, "imag");
316 
317   // TODO: alignment
318   Builder.CreateStore(Val.first, RealPtr, lvalue.isVolatileQualified());
319   Builder.CreateStore(Val.second, ImagPtr, lvalue.isVolatileQualified());
320 }
321 
322 
323 
324 //===----------------------------------------------------------------------===//
325 //                            Visitor Methods
326 //===----------------------------------------------------------------------===//
327 
328 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
329   CGF.ErrorUnsupported(E, "complex expression");
330   llvm::Type *EltTy =
331     CGF.ConvertType(getComplexType(E->getType())->getElementType());
332   llvm::Value *U = llvm::UndefValue::get(EltTy);
333   return ComplexPairTy(U, U);
334 }
335 
336 ComplexPairTy ComplexExprEmitter::
337 VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
338   llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
339   return ComplexPairTy(llvm::Constant::getNullValue(Imag->getType()), Imag);
340 }
341 
342 
343 ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
344   if (E->getCallReturnType()->isReferenceType())
345     return EmitLoadOfLValue(E);
346 
347   return CGF.EmitCallExpr(E).getComplexVal();
348 }
349 
350 ComplexPairTy ComplexExprEmitter::VisitStmtExpr(const StmtExpr *E) {
351   CodeGenFunction::StmtExprEvaluation eval(CGF);
352   return CGF.EmitCompoundStmt(*E->getSubStmt(), true).getComplexVal();
353 }
354 
355 /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
356 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
357                                                            QualType SrcType,
358                                                            QualType DestType) {
359   // Get the src/dest element type.
360   SrcType = SrcType->castAs<ComplexType>()->getElementType();
361   DestType = DestType->castAs<ComplexType>()->getElementType();
362 
363   // C99 6.3.1.6: When a value of complex type is converted to another
364   // complex type, both the real and imaginary parts follow the conversion
365   // rules for the corresponding real types.
366   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType);
367   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType);
368   return Val;
369 }
370 
371 ComplexPairTy ComplexExprEmitter::EmitCast(CastExpr::CastKind CK, Expr *Op,
372                                            QualType DestTy) {
373   switch (CK) {
374   case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!");
375 
376   // Atomic to non-atomic casts may be more than a no-op for some platforms and
377   // for some types.
378   case CK_AtomicToNonAtomic:
379   case CK_NonAtomicToAtomic:
380   case CK_NoOp:
381   case CK_LValueToRValue:
382   case CK_UserDefinedConversion:
383     return Visit(Op);
384 
385   case CK_LValueBitCast: {
386     LValue origLV = CGF.EmitLValue(Op);
387     llvm::Value *V = origLV.getAddress();
388     V = Builder.CreateBitCast(V,
389                     CGF.ConvertType(CGF.getContext().getPointerType(DestTy)));
390     return EmitLoadOfLValue(CGF.MakeAddrLValue(V, DestTy,
391                                                origLV.getAlignment()));
392   }
393 
394   case CK_BitCast:
395   case CK_BaseToDerived:
396   case CK_DerivedToBase:
397   case CK_UncheckedDerivedToBase:
398   case CK_Dynamic:
399   case CK_ToUnion:
400   case CK_ArrayToPointerDecay:
401   case CK_FunctionToPointerDecay:
402   case CK_NullToPointer:
403   case CK_NullToMemberPointer:
404   case CK_BaseToDerivedMemberPointer:
405   case CK_DerivedToBaseMemberPointer:
406   case CK_MemberPointerToBoolean:
407   case CK_ReinterpretMemberPointer:
408   case CK_ConstructorConversion:
409   case CK_IntegralToPointer:
410   case CK_PointerToIntegral:
411   case CK_PointerToBoolean:
412   case CK_ToVoid:
413   case CK_VectorSplat:
414   case CK_IntegralCast:
415   case CK_IntegralToBoolean:
416   case CK_IntegralToFloating:
417   case CK_FloatingToIntegral:
418   case CK_FloatingToBoolean:
419   case CK_FloatingCast:
420   case CK_CPointerToObjCPointerCast:
421   case CK_BlockPointerToObjCPointerCast:
422   case CK_AnyPointerToBlockPointerCast:
423   case CK_ObjCObjectLValueCast:
424   case CK_FloatingComplexToReal:
425   case CK_FloatingComplexToBoolean:
426   case CK_IntegralComplexToReal:
427   case CK_IntegralComplexToBoolean:
428   case CK_ARCProduceObject:
429   case CK_ARCConsumeObject:
430   case CK_ARCReclaimReturnedObject:
431   case CK_ARCExtendBlockObject:
432   case CK_CopyAndAutoreleaseBlockObject:
433   case CK_BuiltinFnToFnPtr:
434   case CK_ZeroToOCLEvent:
435     llvm_unreachable("invalid cast kind for complex value");
436 
437   case CK_FloatingRealToComplex:
438   case CK_IntegralRealToComplex: {
439     llvm::Value *Elt = CGF.EmitScalarExpr(Op);
440 
441     // Convert the input element to the element type of the complex.
442     DestTy = DestTy->castAs<ComplexType>()->getElementType();
443     Elt = CGF.EmitScalarConversion(Elt, Op->getType(), DestTy);
444 
445     // Return (realval, 0).
446     return ComplexPairTy(Elt, llvm::Constant::getNullValue(Elt->getType()));
447   }
448 
449   case CK_FloatingComplexCast:
450   case CK_FloatingComplexToIntegralComplex:
451   case CK_IntegralComplexCast:
452   case CK_IntegralComplexToFloatingComplex:
453     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
454   }
455 
456   llvm_unreachable("unknown cast resulting in complex value");
457 }
458 
459 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
460   TestAndClearIgnoreReal();
461   TestAndClearIgnoreImag();
462   ComplexPairTy Op = Visit(E->getSubExpr());
463 
464   llvm::Value *ResR, *ResI;
465   if (Op.first->getType()->isFloatingPointTy()) {
466     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
467     ResI = Builder.CreateFNeg(Op.second, "neg.i");
468   } else {
469     ResR = Builder.CreateNeg(Op.first,  "neg.r");
470     ResI = Builder.CreateNeg(Op.second, "neg.i");
471   }
472   return ComplexPairTy(ResR, ResI);
473 }
474 
475 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
476   TestAndClearIgnoreReal();
477   TestAndClearIgnoreImag();
478   // ~(a+ib) = a + i*-b
479   ComplexPairTy Op = Visit(E->getSubExpr());
480   llvm::Value *ResI;
481   if (Op.second->getType()->isFloatingPointTy())
482     ResI = Builder.CreateFNeg(Op.second, "conj.i");
483   else
484     ResI = Builder.CreateNeg(Op.second, "conj.i");
485 
486   return ComplexPairTy(Op.first, ResI);
487 }
488 
489 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
490   llvm::Value *ResR, *ResI;
491 
492   if (Op.LHS.first->getType()->isFloatingPointTy()) {
493     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
494     ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
495   } else {
496     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
497     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
498   }
499   return ComplexPairTy(ResR, ResI);
500 }
501 
502 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
503   llvm::Value *ResR, *ResI;
504   if (Op.LHS.first->getType()->isFloatingPointTy()) {
505     ResR = Builder.CreateFSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
506     ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
507   } else {
508     ResR = Builder.CreateSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
509     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
510   }
511   return ComplexPairTy(ResR, ResI);
512 }
513 
514 
515 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
516   using llvm::Value;
517   Value *ResR, *ResI;
518 
519   if (Op.LHS.first->getType()->isFloatingPointTy()) {
520     Value *ResRl = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
521     Value *ResRr = Builder.CreateFMul(Op.LHS.second, Op.RHS.second,"mul.rr");
522     ResR  = Builder.CreateFSub(ResRl, ResRr, "mul.r");
523 
524     Value *ResIl = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il");
525     Value *ResIr = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
526     ResI  = Builder.CreateFAdd(ResIl, ResIr, "mul.i");
527   } else {
528     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
529     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
530     ResR  = Builder.CreateSub(ResRl, ResRr, "mul.r");
531 
532     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
533     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
534     ResI  = Builder.CreateAdd(ResIl, ResIr, "mul.i");
535   }
536   return ComplexPairTy(ResR, ResI);
537 }
538 
539 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
540   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
541   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
542 
543 
544   llvm::Value *DSTr, *DSTi;
545   if (Op.LHS.first->getType()->isFloatingPointTy()) {
546     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
547     llvm::Value *Tmp1 = Builder.CreateFMul(LHSr, RHSr); // a*c
548     llvm::Value *Tmp2 = Builder.CreateFMul(LHSi, RHSi); // b*d
549     llvm::Value *Tmp3 = Builder.CreateFAdd(Tmp1, Tmp2); // ac+bd
550 
551     llvm::Value *Tmp4 = Builder.CreateFMul(RHSr, RHSr); // c*c
552     llvm::Value *Tmp5 = Builder.CreateFMul(RHSi, RHSi); // d*d
553     llvm::Value *Tmp6 = Builder.CreateFAdd(Tmp4, Tmp5); // cc+dd
554 
555     llvm::Value *Tmp7 = Builder.CreateFMul(LHSi, RHSr); // b*c
556     llvm::Value *Tmp8 = Builder.CreateFMul(LHSr, RHSi); // a*d
557     llvm::Value *Tmp9 = Builder.CreateFSub(Tmp7, Tmp8); // bc-ad
558 
559     DSTr = Builder.CreateFDiv(Tmp3, Tmp6);
560     DSTi = Builder.CreateFDiv(Tmp9, Tmp6);
561   } else {
562     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
563     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr); // a*c
564     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi); // b*d
565     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2); // ac+bd
566 
567     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr); // c*c
568     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi); // d*d
569     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5); // cc+dd
570 
571     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr); // b*c
572     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi); // a*d
573     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8); // bc-ad
574 
575     if (Op.Ty->castAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
576       DSTr = Builder.CreateUDiv(Tmp3, Tmp6);
577       DSTi = Builder.CreateUDiv(Tmp9, Tmp6);
578     } else {
579       DSTr = Builder.CreateSDiv(Tmp3, Tmp6);
580       DSTi = Builder.CreateSDiv(Tmp9, Tmp6);
581     }
582   }
583 
584   return ComplexPairTy(DSTr, DSTi);
585 }
586 
587 ComplexExprEmitter::BinOpInfo
588 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
589   TestAndClearIgnoreReal();
590   TestAndClearIgnoreImag();
591   BinOpInfo Ops;
592   Ops.LHS = Visit(E->getLHS());
593   Ops.RHS = Visit(E->getRHS());
594   Ops.Ty = E->getType();
595   return Ops;
596 }
597 
598 
599 LValue ComplexExprEmitter::
600 EmitCompoundAssignLValue(const CompoundAssignOperator *E,
601           ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&),
602                          ComplexPairTy &Val) {
603   TestAndClearIgnoreReal();
604   TestAndClearIgnoreImag();
605   QualType LHSTy = E->getLHS()->getType();
606 
607   BinOpInfo OpInfo;
608 
609   // Load the RHS and LHS operands.
610   // __block variables need to have the rhs evaluated first, plus this should
611   // improve codegen a little.
612   OpInfo.Ty = E->getComputationResultType();
613 
614   // The RHS should have been converted to the computation type.
615   assert(OpInfo.Ty->isAnyComplexType());
616   assert(CGF.getContext().hasSameUnqualifiedType(OpInfo.Ty,
617                                                  E->getRHS()->getType()));
618   OpInfo.RHS = Visit(E->getRHS());
619 
620   LValue LHS = CGF.EmitLValue(E->getLHS());
621 
622   // Load from the l-value.
623   ComplexPairTy LHSComplexPair = EmitLoadOfLValue(LHS);
624 
625   OpInfo.LHS = EmitComplexToComplexCast(LHSComplexPair, LHSTy, OpInfo.Ty);
626 
627   // Expand the binary operator.
628   ComplexPairTy Result = (this->*Func)(OpInfo);
629 
630   // Truncate the result back to the LHS type.
631   Result = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
632   Val = Result;
633 
634   // Store the result value into the LHS lvalue.
635   EmitStoreOfComplex(Result, LHS, /*isInit*/ false);
636 
637   return LHS;
638 }
639 
640 // Compound assignments.
641 ComplexPairTy ComplexExprEmitter::
642 EmitCompoundAssign(const CompoundAssignOperator *E,
643                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
644   ComplexPairTy Val;
645   LValue LV = EmitCompoundAssignLValue(E, Func, Val);
646 
647   // The result of an assignment in C is the assigned r-value.
648   if (!CGF.getLangOpts().CPlusPlus)
649     return Val;
650 
651   // If the lvalue is non-volatile, return the computed value of the assignment.
652   if (!LV.isVolatileQualified())
653     return Val;
654 
655   return EmitLoadOfLValue(LV);
656 }
657 
658 LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
659                                                ComplexPairTy &Val) {
660   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
661                                                  E->getRHS()->getType()) &&
662          "Invalid assignment");
663   TestAndClearIgnoreReal();
664   TestAndClearIgnoreImag();
665 
666   // Emit the RHS.  __block variables need the RHS evaluated first.
667   Val = Visit(E->getRHS());
668 
669   // Compute the address to store into.
670   LValue LHS = CGF.EmitLValue(E->getLHS());
671 
672   // Store the result value into the LHS lvalue.
673   EmitStoreOfComplex(Val, LHS, /*isInit*/ false);
674 
675   return LHS;
676 }
677 
678 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
679   ComplexPairTy Val;
680   LValue LV = EmitBinAssignLValue(E, Val);
681 
682   // The result of an assignment in C is the assigned r-value.
683   if (!CGF.getLangOpts().CPlusPlus)
684     return Val;
685 
686   // If the lvalue is non-volatile, return the computed value of the assignment.
687   if (!LV.isVolatileQualified())
688     return Val;
689 
690   return EmitLoadOfLValue(LV);
691 }
692 
693 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
694   CGF.EmitIgnoredExpr(E->getLHS());
695   return Visit(E->getRHS());
696 }
697 
698 ComplexPairTy ComplexExprEmitter::
699 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
700   TestAndClearIgnoreReal();
701   TestAndClearIgnoreImag();
702   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
703   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
704   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
705 
706   // Bind the common expression if necessary.
707   CodeGenFunction::OpaqueValueMapping binding(CGF, E);
708 
709   CodeGenFunction::ConditionalEvaluation eval(CGF);
710   CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
711 
712   eval.begin(CGF);
713   CGF.EmitBlock(LHSBlock);
714   ComplexPairTy LHS = Visit(E->getTrueExpr());
715   LHSBlock = Builder.GetInsertBlock();
716   CGF.EmitBranch(ContBlock);
717   eval.end(CGF);
718 
719   eval.begin(CGF);
720   CGF.EmitBlock(RHSBlock);
721   ComplexPairTy RHS = Visit(E->getFalseExpr());
722   RHSBlock = Builder.GetInsertBlock();
723   CGF.EmitBlock(ContBlock);
724   eval.end(CGF);
725 
726   // Create a PHI node for the real part.
727   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.r");
728   RealPN->addIncoming(LHS.first, LHSBlock);
729   RealPN->addIncoming(RHS.first, RHSBlock);
730 
731   // Create a PHI node for the imaginary part.
732   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.i");
733   ImagPN->addIncoming(LHS.second, LHSBlock);
734   ImagPN->addIncoming(RHS.second, RHSBlock);
735 
736   return ComplexPairTy(RealPN, ImagPN);
737 }
738 
739 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
740   return Visit(E->getChosenSubExpr(CGF.getContext()));
741 }
742 
743 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
744     bool Ignore = TestAndClearIgnoreReal();
745     (void)Ignore;
746     assert (Ignore == false && "init list ignored");
747     Ignore = TestAndClearIgnoreImag();
748     (void)Ignore;
749     assert (Ignore == false && "init list ignored");
750 
751   if (E->getNumInits() == 2) {
752     llvm::Value *Real = CGF.EmitScalarExpr(E->getInit(0));
753     llvm::Value *Imag = CGF.EmitScalarExpr(E->getInit(1));
754     return ComplexPairTy(Real, Imag);
755   } else if (E->getNumInits() == 1) {
756     return Visit(E->getInit(0));
757   }
758 
759   // Empty init list intializes to null
760   assert(E->getNumInits() == 0 && "Unexpected number of inits");
761   QualType Ty = E->getType()->castAs<ComplexType>()->getElementType();
762   llvm::Type* LTy = CGF.ConvertType(Ty);
763   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
764   return ComplexPairTy(zeroConstant, zeroConstant);
765 }
766 
767 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
768   llvm::Value *ArgValue = CGF.EmitVAListRef(E->getSubExpr());
769   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, E->getType());
770 
771   if (!ArgPtr) {
772     CGF.ErrorUnsupported(E, "complex va_arg expression");
773     llvm::Type *EltTy =
774       CGF.ConvertType(E->getType()->castAs<ComplexType>()->getElementType());
775     llvm::Value *U = llvm::UndefValue::get(EltTy);
776     return ComplexPairTy(U, U);
777   }
778 
779   return EmitLoadOfLValue(
780                CGF.MakeNaturalAlignAddrLValue(ArgPtr, E->getType()));
781 }
782 
783 //===----------------------------------------------------------------------===//
784 //                         Entry Point into this File
785 //===----------------------------------------------------------------------===//
786 
787 /// EmitComplexExpr - Emit the computation of the specified expression of
788 /// complex type, ignoring the result.
789 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
790                                                bool IgnoreImag) {
791   assert(E && getComplexType(E->getType()) &&
792          "Invalid complex expression to emit");
793 
794   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag)
795     .Visit(const_cast<Expr*>(E));
796 }
797 
798 void CodeGenFunction::EmitComplexExprIntoLValue(const Expr *E, LValue dest,
799                                                 bool isInit) {
800   assert(E && getComplexType(E->getType()) &&
801          "Invalid complex expression to emit");
802   ComplexExprEmitter Emitter(*this);
803   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
804   Emitter.EmitStoreOfComplex(Val, dest, isInit);
805 }
806 
807 /// EmitStoreOfComplex - Store a complex number into the specified l-value.
808 void CodeGenFunction::EmitStoreOfComplex(ComplexPairTy V, LValue dest,
809                                          bool isInit) {
810   ComplexExprEmitter(*this).EmitStoreOfComplex(V, dest, isInit);
811 }
812 
813 /// EmitLoadOfComplex - Load a complex number from the specified address.
814 ComplexPairTy CodeGenFunction::EmitLoadOfComplex(LValue src) {
815   return ComplexExprEmitter(*this).EmitLoadOfLValue(src);
816 }
817 
818 LValue CodeGenFunction::EmitComplexAssignmentLValue(const BinaryOperator *E) {
819   assert(E->getOpcode() == BO_Assign);
820   ComplexPairTy Val; // ignored
821   return ComplexExprEmitter(*this).EmitBinAssignLValue(E, Val);
822 }
823 
824 LValue CodeGenFunction::
825 EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E) {
826   ComplexPairTy(ComplexExprEmitter::*Op)(const ComplexExprEmitter::BinOpInfo &);
827   switch (E->getOpcode()) {
828   case BO_MulAssign: Op = &ComplexExprEmitter::EmitBinMul; break;
829   case BO_DivAssign: Op = &ComplexExprEmitter::EmitBinDiv; break;
830   case BO_SubAssign: Op = &ComplexExprEmitter::EmitBinSub; break;
831   case BO_AddAssign: Op = &ComplexExprEmitter::EmitBinAdd; break;
832 
833   default:
834     llvm_unreachable("unexpected complex compound assignment");
835   }
836 
837   ComplexPairTy Val; // ignored
838   return ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
839 }
840