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     LValue LV = CGF.EmitLValue(E);
64     if (LV.isSimple())
65       return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
66 
67     assert(LV.isPropertyRef() && "Unknown LValue type!");
68     return CGF.EmitLoadOfPropertyRefLValue(LV).getComplexVal();
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   /// EmitStoreOfComplex - Store the specified real/imag parts into the
76   /// specified value pointer.
77   void EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *ResPtr, bool isVol);
78 
79   /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
80   ComplexPairTy EmitComplexToComplexCast(ComplexPairTy Val, QualType SrcType,
81                                          QualType DestType);
82 
83   //===--------------------------------------------------------------------===//
84   //                            Visitor Methods
85   //===--------------------------------------------------------------------===//
86 
87   ComplexPairTy Visit(Expr *E) {
88     llvm::DenseMap<const Expr *, ComplexPairTy>::iterator I =
89       CGF.ConditionalSaveComplexExprs.find(E);
90     if (I != CGF.ConditionalSaveComplexExprs.end())
91       return I->second;
92 
93       return StmtVisitor<ComplexExprEmitter, ComplexPairTy>::Visit(E);
94   }
95 
96   ComplexPairTy VisitStmt(Stmt *S) {
97     S->dump(CGF.getContext().getSourceManager());
98     assert(0 && "Stmt can't have complex result type!");
99     return ComplexPairTy();
100   }
101   ComplexPairTy VisitExpr(Expr *S);
102   ComplexPairTy VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr());}
103   ComplexPairTy VisitImaginaryLiteral(const ImaginaryLiteral *IL);
104 
105   // l-values.
106   ComplexPairTy VisitDeclRefExpr(const Expr *E) { return EmitLoadOfLValue(E); }
107   ComplexPairTy VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
108     return EmitLoadOfLValue(E);
109   }
110   ComplexPairTy VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
111     assert(E->getObjectKind() == OK_Ordinary);
112     return EmitLoadOfLValue(E);
113   }
114   ComplexPairTy VisitObjCMessageExpr(ObjCMessageExpr *E) {
115     return CGF.EmitObjCMessageExpr(E).getComplexVal();
116   }
117   ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
118   ComplexPairTy VisitMemberExpr(const Expr *E) { return EmitLoadOfLValue(E); }
119 
120   // FIXME: CompoundLiteralExpr
121 
122   ComplexPairTy EmitCast(CastExpr::CastKind CK, Expr *Op, QualType DestTy);
123   ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
124     // Unlike for scalars, we don't have to worry about function->ptr demotion
125     // here.
126     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
127   }
128   ComplexPairTy VisitCastExpr(CastExpr *E) {
129     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
130   }
131   ComplexPairTy VisitCallExpr(const CallExpr *E);
132   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
133 
134   // Operators.
135   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
136                                    bool isInc, bool isPre) {
137     LValue LV = CGF.EmitLValue(E->getSubExpr());
138     return CGF.EmitComplexPrePostIncDec(E, LV, isInc, isPre);
139   }
140   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
141     return VisitPrePostIncDec(E, false, false);
142   }
143   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
144     return VisitPrePostIncDec(E, true, false);
145   }
146   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
147     return VisitPrePostIncDec(E, false, true);
148   }
149   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
150     return VisitPrePostIncDec(E, true, true);
151   }
152   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
153   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
154     TestAndClearIgnoreReal();
155     TestAndClearIgnoreImag();
156     return Visit(E->getSubExpr());
157   }
158   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
159   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
160   // LNot,Real,Imag never return complex.
161   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
162     return Visit(E->getSubExpr());
163   }
164   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
165     return Visit(DAE->getExpr());
166   }
167   ComplexPairTy VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) {
168     return CGF.EmitCXXExprWithTemporaries(E).getComplexVal();
169   }
170   ComplexPairTy VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
171     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
172     QualType Elem = E->getType()->getAs<ComplexType>()->getElementType();
173     llvm::Constant *Null = llvm::Constant::getNullValue(CGF.ConvertType(Elem));
174     return ComplexPairTy(Null, Null);
175   }
176   ComplexPairTy VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
177     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
178     QualType Elem = E->getType()->getAs<ComplexType>()->getElementType();
179     llvm::Constant *Null =
180                        llvm::Constant::getNullValue(CGF.ConvertType(Elem));
181     return ComplexPairTy(Null, Null);
182   }
183 
184   struct BinOpInfo {
185     ComplexPairTy LHS;
186     ComplexPairTy RHS;
187     QualType Ty;  // Computation Type.
188   };
189 
190   BinOpInfo EmitBinOps(const BinaryOperator *E);
191   LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
192                                   ComplexPairTy (ComplexExprEmitter::*Func)
193                                   (const BinOpInfo &),
194                                   ComplexPairTy &Val);
195   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
196                                    ComplexPairTy (ComplexExprEmitter::*Func)
197                                    (const BinOpInfo &));
198 
199   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
200   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
201   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
202   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
203 
204   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
205     return EmitBinAdd(EmitBinOps(E));
206   }
207   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
208     return EmitBinSub(EmitBinOps(E));
209   }
210   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
211     return EmitBinMul(EmitBinOps(E));
212   }
213   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
214     return EmitBinDiv(EmitBinOps(E));
215   }
216 
217   // Compound assignments.
218   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
219     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
220   }
221   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
222     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
223   }
224   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
225     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
226   }
227   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
228     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
229   }
230 
231   // GCC rejects rem/and/or/xor for integer complex.
232   // Logical and/or always return int, never complex.
233 
234   // No comparisons produce a complex result.
235 
236   LValue EmitBinAssignLValue(const BinaryOperator *E,
237                              ComplexPairTy &Val);
238   ComplexPairTy VisitBinAssign     (const BinaryOperator *E);
239   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
240 
241 
242   ComplexPairTy VisitConditionalOperator(const ConditionalOperator *CO);
243   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
244 
245   ComplexPairTy VisitInitListExpr(InitListExpr *E);
246 
247   ComplexPairTy VisitVAArgExpr(VAArgExpr *E);
248 };
249 }  // end anonymous namespace.
250 
251 //===----------------------------------------------------------------------===//
252 //                                Utilities
253 //===----------------------------------------------------------------------===//
254 
255 /// EmitLoadOfComplex - Given an RValue reference for a complex, emit code to
256 /// load the real and imaginary pieces, returning them as Real/Imag.
257 ComplexPairTy ComplexExprEmitter::EmitLoadOfComplex(llvm::Value *SrcPtr,
258                                                     bool isVolatile) {
259   llvm::Value *Real=0, *Imag=0;
260 
261   if (!IgnoreReal || isVolatile) {
262     llvm::Value *RealP = Builder.CreateStructGEP(SrcPtr, 0,
263                                                  SrcPtr->getName() + ".realp");
264     Real = Builder.CreateLoad(RealP, isVolatile, SrcPtr->getName() + ".real");
265   }
266 
267   if (!IgnoreImag || isVolatile) {
268     llvm::Value *ImagP = Builder.CreateStructGEP(SrcPtr, 1,
269                                                  SrcPtr->getName() + ".imagp");
270     Imag = Builder.CreateLoad(ImagP, isVolatile, SrcPtr->getName() + ".imag");
271   }
272   return ComplexPairTy(Real, Imag);
273 }
274 
275 /// EmitStoreOfComplex - Store the specified real/imag parts into the
276 /// specified value pointer.
277 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *Ptr,
278                                             bool isVolatile) {
279   llvm::Value *RealPtr = Builder.CreateStructGEP(Ptr, 0, "real");
280   llvm::Value *ImagPtr = Builder.CreateStructGEP(Ptr, 1, "imag");
281 
282   Builder.CreateStore(Val.first, RealPtr, isVolatile);
283   Builder.CreateStore(Val.second, ImagPtr, isVolatile);
284 }
285 
286 
287 
288 //===----------------------------------------------------------------------===//
289 //                            Visitor Methods
290 //===----------------------------------------------------------------------===//
291 
292 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
293   CGF.ErrorUnsupported(E, "complex expression");
294   const llvm::Type *EltTy =
295     CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
296   llvm::Value *U = llvm::UndefValue::get(EltTy);
297   return ComplexPairTy(U, U);
298 }
299 
300 ComplexPairTy ComplexExprEmitter::
301 VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
302   llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
303   return
304         ComplexPairTy(llvm::Constant::getNullValue(Imag->getType()), Imag);
305 }
306 
307 
308 ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
309   if (E->getCallReturnType()->isReferenceType())
310     return EmitLoadOfLValue(E);
311 
312   return CGF.EmitCallExpr(E).getComplexVal();
313 }
314 
315 ComplexPairTy ComplexExprEmitter::VisitStmtExpr(const StmtExpr *E) {
316   return CGF.EmitCompoundStmt(*E->getSubStmt(), true).getComplexVal();
317 }
318 
319 /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
320 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
321                                                            QualType SrcType,
322                                                            QualType DestType) {
323   // Get the src/dest element type.
324   SrcType = SrcType->getAs<ComplexType>()->getElementType();
325   DestType = DestType->getAs<ComplexType>()->getElementType();
326 
327   // C99 6.3.1.6: When a value of complex type is converted to another
328   // complex type, both the real and imaginary parts follow the conversion
329   // rules for the corresponding real types.
330   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType);
331   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType);
332   return Val;
333 }
334 
335 ComplexPairTy ComplexExprEmitter::EmitCast(CastExpr::CastKind CK, Expr *Op,
336                                            QualType DestTy) {
337   switch (CK) {
338   case CK_GetObjCProperty: {
339     LValue LV = CGF.EmitLValue(Op);
340     assert(LV.isPropertyRef() && "Unknown LValue type!");
341     return CGF.EmitLoadOfPropertyRefLValue(LV).getComplexVal();
342   }
343 
344   case CK_NoOp:
345   case CK_LValueToRValue:
346     return Visit(Op);
347 
348   // TODO: do all of these
349   default:
350     break;
351   }
352 
353   // Two cases here: cast from (complex to complex) and (scalar to complex).
354   if (Op->getType()->isAnyComplexType())
355     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
356 
357   // FIXME: We should be looking at all of the cast kinds here, not
358   // cherry-picking the ones we have test cases for.
359   if (CK == CK_LValueBitCast) {
360     llvm::Value *V = CGF.EmitLValue(Op).getAddress();
361     V = Builder.CreateBitCast(V,
362                       CGF.ConvertType(CGF.getContext().getPointerType(DestTy)));
363     // FIXME: Are the qualifiers correct here?
364     return EmitLoadOfComplex(V, DestTy.isVolatileQualified());
365   }
366 
367   // C99 6.3.1.7: When a value of real type is converted to a complex type, the
368   // real part of the complex result value is determined by the rules of
369   // conversion to the corresponding real type and the imaginary part of the
370   // complex result value is a positive zero or an unsigned zero.
371   llvm::Value *Elt = CGF.EmitScalarExpr(Op);
372 
373   // Convert the input element to the element type of the complex.
374   DestTy = DestTy->getAs<ComplexType>()->getElementType();
375   Elt = CGF.EmitScalarConversion(Elt, Op->getType(), DestTy);
376 
377   // Return (realval, 0).
378   return ComplexPairTy(Elt, llvm::Constant::getNullValue(Elt->getType()));
379 }
380 
381 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
382   TestAndClearIgnoreReal();
383   TestAndClearIgnoreImag();
384   ComplexPairTy Op = Visit(E->getSubExpr());
385 
386   llvm::Value *ResR, *ResI;
387   if (Op.first->getType()->isFloatingPointTy()) {
388     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
389     ResI = Builder.CreateFNeg(Op.second, "neg.i");
390   } else {
391     ResR = Builder.CreateNeg(Op.first,  "neg.r");
392     ResI = Builder.CreateNeg(Op.second, "neg.i");
393   }
394   return ComplexPairTy(ResR, ResI);
395 }
396 
397 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
398   TestAndClearIgnoreReal();
399   TestAndClearIgnoreImag();
400   // ~(a+ib) = a + i*-b
401   ComplexPairTy Op = Visit(E->getSubExpr());
402   llvm::Value *ResI;
403   if (Op.second->getType()->isFloatingPointTy())
404     ResI = Builder.CreateFNeg(Op.second, "conj.i");
405   else
406     ResI = Builder.CreateNeg(Op.second, "conj.i");
407 
408   return ComplexPairTy(Op.first, ResI);
409 }
410 
411 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
412   llvm::Value *ResR, *ResI;
413 
414   if (Op.LHS.first->getType()->isFloatingPointTy()) {
415     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
416     ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
417   } else {
418     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
419     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
420   }
421   return ComplexPairTy(ResR, ResI);
422 }
423 
424 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
425   llvm::Value *ResR, *ResI;
426   if (Op.LHS.first->getType()->isFloatingPointTy()) {
427     ResR = Builder.CreateFSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
428     ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
429   } else {
430     ResR = Builder.CreateSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
431     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
432   }
433   return ComplexPairTy(ResR, ResI);
434 }
435 
436 
437 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
438   using llvm::Value;
439   Value *ResR, *ResI;
440 
441   if (Op.LHS.first->getType()->isFloatingPointTy()) {
442     Value *ResRl = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
443     Value *ResRr = Builder.CreateFMul(Op.LHS.second, Op.RHS.second,"mul.rr");
444     ResR  = Builder.CreateFSub(ResRl, ResRr, "mul.r");
445 
446     Value *ResIl = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il");
447     Value *ResIr = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
448     ResI  = Builder.CreateFAdd(ResIl, ResIr, "mul.i");
449   } else {
450     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
451     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
452     ResR  = Builder.CreateSub(ResRl, ResRr, "mul.r");
453 
454     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
455     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
456     ResI  = Builder.CreateAdd(ResIl, ResIr, "mul.i");
457   }
458   return ComplexPairTy(ResR, ResI);
459 }
460 
461 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
462   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
463   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
464 
465 
466   llvm::Value *DSTr, *DSTi;
467   if (Op.LHS.first->getType()->isFloatingPointTy()) {
468     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
469     llvm::Value *Tmp1 = Builder.CreateFMul(LHSr, RHSr, "tmp"); // a*c
470     llvm::Value *Tmp2 = Builder.CreateFMul(LHSi, RHSi, "tmp"); // b*d
471     llvm::Value *Tmp3 = Builder.CreateFAdd(Tmp1, Tmp2, "tmp"); // ac+bd
472 
473     llvm::Value *Tmp4 = Builder.CreateFMul(RHSr, RHSr, "tmp"); // c*c
474     llvm::Value *Tmp5 = Builder.CreateFMul(RHSi, RHSi, "tmp"); // d*d
475     llvm::Value *Tmp6 = Builder.CreateFAdd(Tmp4, Tmp5, "tmp"); // cc+dd
476 
477     llvm::Value *Tmp7 = Builder.CreateFMul(LHSi, RHSr, "tmp"); // b*c
478     llvm::Value *Tmp8 = Builder.CreateFMul(LHSr, RHSi, "tmp"); // a*d
479     llvm::Value *Tmp9 = Builder.CreateFSub(Tmp7, Tmp8, "tmp"); // bc-ad
480 
481     DSTr = Builder.CreateFDiv(Tmp3, Tmp6, "tmp");
482     DSTi = Builder.CreateFDiv(Tmp9, Tmp6, "tmp");
483   } else {
484     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
485     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr, "tmp"); // a*c
486     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi, "tmp"); // b*d
487     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2, "tmp"); // ac+bd
488 
489     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr, "tmp"); // c*c
490     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi, "tmp"); // d*d
491     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5, "tmp"); // cc+dd
492 
493     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr, "tmp"); // b*c
494     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi, "tmp"); // a*d
495     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8, "tmp"); // bc-ad
496 
497     if (Op.Ty->getAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
498       DSTr = Builder.CreateUDiv(Tmp3, Tmp6, "tmp");
499       DSTi = Builder.CreateUDiv(Tmp9, Tmp6, "tmp");
500     } else {
501       DSTr = Builder.CreateSDiv(Tmp3, Tmp6, "tmp");
502       DSTi = Builder.CreateSDiv(Tmp9, Tmp6, "tmp");
503     }
504   }
505 
506   return ComplexPairTy(DSTr, DSTi);
507 }
508 
509 ComplexExprEmitter::BinOpInfo
510 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
511   TestAndClearIgnoreReal();
512   TestAndClearIgnoreImag();
513   BinOpInfo Ops;
514   Ops.LHS = Visit(E->getLHS());
515   Ops.RHS = Visit(E->getRHS());
516   Ops.Ty = E->getType();
517   return Ops;
518 }
519 
520 
521 LValue ComplexExprEmitter::
522 EmitCompoundAssignLValue(const CompoundAssignOperator *E,
523           ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&),
524                          ComplexPairTy &Val) {
525   TestAndClearIgnoreReal();
526   TestAndClearIgnoreImag();
527   QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType();
528 
529   BinOpInfo OpInfo;
530 
531   // Load the RHS and LHS operands.
532   // __block variables need to have the rhs evaluated first, plus this should
533   // improve codegen a little.
534   OpInfo.Ty = E->getComputationResultType();
535 
536   // The RHS should have been converted to the computation type.
537   assert(OpInfo.Ty->isAnyComplexType());
538   assert(CGF.getContext().hasSameUnqualifiedType(OpInfo.Ty,
539                                                  E->getRHS()->getType()));
540   OpInfo.RHS = Visit(E->getRHS());
541 
542   LValue LHS = CGF.EmitLValue(E->getLHS());
543   // We know the LHS is a complex lvalue.
544   ComplexPairTy LHSComplexPair;
545   if (LHS.isPropertyRef())
546     LHSComplexPair = CGF.EmitLoadOfPropertyRefLValue(LHS).getComplexVal();
547   else
548     LHSComplexPair = EmitLoadOfComplex(LHS.getAddress(),
549                                        LHS.isVolatileQualified());
550 
551   OpInfo.LHS = EmitComplexToComplexCast(LHSComplexPair, LHSTy, OpInfo.Ty);
552 
553   // Expand the binary operator.
554   ComplexPairTy Result = (this->*Func)(OpInfo);
555 
556   // Truncate the result back to the LHS type.
557   Result = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
558   Val = Result;
559 
560   // Store the result value into the LHS lvalue.
561   if (LHS.isPropertyRef())
562     CGF.EmitStoreThroughPropertyRefLValue(RValue::getComplex(Result), LHS);
563   else
564     EmitStoreOfComplex(Result, LHS.getAddress(), LHS.isVolatileQualified());
565 
566   return LHS;
567 }
568 
569 // Compound assignments.
570 ComplexPairTy ComplexExprEmitter::
571 EmitCompoundAssign(const CompoundAssignOperator *E,
572                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
573   ComplexPairTy Val;
574   LValue LV = EmitCompoundAssignLValue(E, Func, Val);
575 
576   // The result of an assignment in C is the assigned r-value.
577   if (!CGF.getContext().getLangOptions().CPlusPlus)
578     return Val;
579 
580   // Objective-C property assignment never reloads the value following a store.
581   if (LV.isPropertyRef())
582     return Val;
583 
584   // If the lvalue is non-volatile, return the computed value of the assignment.
585   if (!LV.isVolatileQualified())
586     return Val;
587 
588   return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
589 }
590 
591 LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
592                                                ComplexPairTy &Val) {
593   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
594                                                  E->getRHS()->getType()) &&
595          "Invalid assignment");
596   TestAndClearIgnoreReal();
597   TestAndClearIgnoreImag();
598 
599   // Emit the RHS.
600   Val = Visit(E->getRHS());
601 
602   // Compute the address to store into.
603   LValue LHS = CGF.EmitLValue(E->getLHS());
604 
605   // Store the result value into the LHS lvalue.
606   if (LHS.isPropertyRef())
607     CGF.EmitStoreThroughPropertyRefLValue(RValue::getComplex(Val), LHS);
608   else
609     EmitStoreOfComplex(Val, LHS.getAddress(), LHS.isVolatileQualified());
610 
611   return LHS;
612 }
613 
614 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
615   ComplexPairTy Val;
616   LValue LV = EmitBinAssignLValue(E, Val);
617 
618   // The result of an assignment in C is the assigned r-value.
619   if (!CGF.getContext().getLangOptions().CPlusPlus)
620     return Val;
621 
622   // Objective-C property assignment never reloads the value following a store.
623   if (LV.isPropertyRef())
624     return Val;
625 
626   // If the lvalue is non-volatile, return the computed value of the assignment.
627   if (!LV.isVolatileQualified())
628     return Val;
629 
630   return EmitLoadOfComplex(LV.getAddress(), LV.isVolatileQualified());
631 }
632 
633 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
634   CGF.EmitStmt(E->getLHS());
635   CGF.EnsureInsertPoint();
636   return Visit(E->getRHS());
637 }
638 
639 ComplexPairTy ComplexExprEmitter::
640 VisitConditionalOperator(const ConditionalOperator *E) {
641   TestAndClearIgnoreReal();
642   TestAndClearIgnoreImag();
643   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
644   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
645   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
646 
647   if (E->getLHS())
648     CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
649   else {
650     Expr *save = E->getSAVE();
651     assert(save && "VisitConditionalOperator - save is null");
652     // Intentianlly not doing direct assignment to ConditionalSaveExprs[save] !!
653     ComplexPairTy SaveVal = Visit(save);
654     CGF.ConditionalSaveComplexExprs[save] = SaveVal;
655     CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
656   }
657 
658   CGF.EmitBlock(LHSBlock);
659   ComplexPairTy LHS = Visit(E->getTrueExpr());
660   LHSBlock = Builder.GetInsertBlock();
661   CGF.EmitBranch(ContBlock);
662 
663   CGF.EmitBlock(RHSBlock);
664 
665   ComplexPairTy RHS = Visit(E->getRHS());
666   RHSBlock = Builder.GetInsertBlock();
667   CGF.EmitBranch(ContBlock);
668 
669   CGF.EmitBlock(ContBlock);
670 
671   // Create a PHI node for the real part.
672   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), "cond.r");
673   RealPN->reserveOperandSpace(2);
674   RealPN->addIncoming(LHS.first, LHSBlock);
675   RealPN->addIncoming(RHS.first, RHSBlock);
676 
677   // Create a PHI node for the imaginary part.
678   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), "cond.i");
679   ImagPN->reserveOperandSpace(2);
680   ImagPN->addIncoming(LHS.second, LHSBlock);
681   ImagPN->addIncoming(RHS.second, RHSBlock);
682 
683   return ComplexPairTy(RealPN, ImagPN);
684 }
685 
686 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
687   return Visit(E->getChosenSubExpr(CGF.getContext()));
688 }
689 
690 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
691     bool Ignore = TestAndClearIgnoreReal();
692     (void)Ignore;
693     assert (Ignore == false && "init list ignored");
694     Ignore = TestAndClearIgnoreImag();
695     (void)Ignore;
696     assert (Ignore == false && "init list ignored");
697   if (E->getNumInits())
698     return Visit(E->getInit(0));
699 
700   // Empty init list intializes to null
701   QualType Ty = E->getType()->getAs<ComplexType>()->getElementType();
702   const llvm::Type* LTy = CGF.ConvertType(Ty);
703   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
704   return ComplexPairTy(zeroConstant, zeroConstant);
705 }
706 
707 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
708   llvm::Value *ArgValue = CGF.EmitVAListRef(E->getSubExpr());
709   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, E->getType());
710 
711   if (!ArgPtr) {
712     CGF.ErrorUnsupported(E, "complex va_arg expression");
713     const llvm::Type *EltTy =
714       CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
715     llvm::Value *U = llvm::UndefValue::get(EltTy);
716     return ComplexPairTy(U, U);
717   }
718 
719   // FIXME Volatility.
720   return EmitLoadOfComplex(ArgPtr, false);
721 }
722 
723 //===----------------------------------------------------------------------===//
724 //                         Entry Point into this File
725 //===----------------------------------------------------------------------===//
726 
727 /// EmitComplexExpr - Emit the computation of the specified expression of
728 /// complex type, ignoring the result.
729 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
730                                                bool IgnoreImag) {
731   assert(E && E->getType()->isAnyComplexType() &&
732          "Invalid complex expression to emit");
733 
734   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag)
735     .Visit(const_cast<Expr*>(E));
736 }
737 
738 /// EmitComplexExprIntoAddr - Emit the computation of the specified expression
739 /// of complex type, storing into the specified Value*.
740 void CodeGenFunction::EmitComplexExprIntoAddr(const Expr *E,
741                                               llvm::Value *DestAddr,
742                                               bool DestIsVolatile) {
743   assert(E && E->getType()->isAnyComplexType() &&
744          "Invalid complex expression to emit");
745   ComplexExprEmitter Emitter(*this);
746   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
747   Emitter.EmitStoreOfComplex(Val, DestAddr, DestIsVolatile);
748 }
749 
750 /// StoreComplexToAddr - Store a complex number into the specified address.
751 void CodeGenFunction::StoreComplexToAddr(ComplexPairTy V,
752                                          llvm::Value *DestAddr,
753                                          bool DestIsVolatile) {
754   ComplexExprEmitter(*this).EmitStoreOfComplex(V, DestAddr, DestIsVolatile);
755 }
756 
757 /// LoadComplexFromAddr - Load a complex number from the specified address.
758 ComplexPairTy CodeGenFunction::LoadComplexFromAddr(llvm::Value *SrcAddr,
759                                                    bool SrcIsVolatile) {
760   return ComplexExprEmitter(*this).EmitLoadOfComplex(SrcAddr, SrcIsVolatile);
761 }
762 
763 LValue CodeGenFunction::EmitComplexAssignmentLValue(const BinaryOperator *E) {
764   ComplexPairTy Val; // ignored
765 
766   ComplexPairTy(ComplexExprEmitter::*Op)(const ComplexExprEmitter::BinOpInfo &);
767 
768   switch (E->getOpcode()) {
769   case BO_Assign:
770     return ComplexExprEmitter(*this).EmitBinAssignLValue(E, Val);
771 
772   case BO_MulAssign: Op = &ComplexExprEmitter::EmitBinMul; break;
773   case BO_DivAssign: Op = &ComplexExprEmitter::EmitBinDiv; break;
774   case BO_SubAssign: Op = &ComplexExprEmitter::EmitBinSub; break;
775   case BO_AddAssign: Op = &ComplexExprEmitter::EmitBinAdd; break;
776 
777   default:
778     llvm_unreachable("unexpected complex compound assignment");
779     Op = 0;
780   }
781 
782   return ComplexExprEmitter(*this).EmitCompoundAssignLValue(
783                                    cast<CompoundAssignOperator>(E), Op, Val);
784 }
785