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/AST.h"
17 #include "llvm/Constants.h"
18 #include "llvm/Function.h"
19 #include "llvm/ADT/SmallString.h"
20 #include "llvm/Support/Compiler.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 VISIBILITY_HIDDEN ComplexExprEmitter
32   : public StmtVisitor<ComplexExprEmitter, ComplexPairTy> {
33   CodeGenFunction &CGF;
34   llvm::LLVMFoldingBuilder &Builder;
35 public:
36   ComplexExprEmitter(CodeGenFunction &cgf) : CGF(cgf), Builder(CGF.Builder) {
37   }
38 
39 
40   //===--------------------------------------------------------------------===//
41   //                               Utilities
42   //===--------------------------------------------------------------------===//
43 
44   /// EmitLoadOfLValue - Given an expression with complex type that represents a
45   /// value l-value, this method emits the address of the l-value, then loads
46   /// and returns the result.
47   ComplexPairTy EmitLoadOfLValue(const Expr *E) {
48     LValue LV = CGF.EmitLValue(E);
49     // FIXME: Volatile
50     return EmitLoadOfComplex(LV.getAddress(), false);
51   }
52 
53   /// EmitLoadOfComplex - Given a pointer to a complex value, emit code to load
54   /// the real and imaginary pieces.
55   ComplexPairTy EmitLoadOfComplex(llvm::Value *SrcPtr, bool isVolatile);
56 
57   /// EmitStoreOfComplex - Store the specified real/imag parts into the
58   /// specified value pointer.
59   void EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *ResPtr, bool isVol);
60 
61   /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
62   ComplexPairTy EmitComplexToComplexCast(ComplexPairTy Val, QualType SrcType,
63                                          QualType DestType);
64 
65   //===--------------------------------------------------------------------===//
66   //                            Visitor Methods
67   //===--------------------------------------------------------------------===//
68 
69   ComplexPairTy VisitStmt(Stmt *S) {
70     S->dump(CGF.getContext().getSourceManager());
71     assert(0 && "Stmt can't have complex result type!");
72     return ComplexPairTy();
73   }
74   ComplexPairTy VisitExpr(Expr *S);
75   ComplexPairTy VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr());}
76   ComplexPairTy VisitImaginaryLiteral(const ImaginaryLiteral *IL);
77 
78   // l-values.
79   ComplexPairTy VisitDeclRefExpr(const Expr *E) { return EmitLoadOfLValue(E); }
80   ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
81   ComplexPairTy VisitMemberExpr(const Expr *E) { return EmitLoadOfLValue(E); }
82 
83   // FIXME: CompoundLiteralExpr
84 
85   ComplexPairTy EmitCast(Expr *Op, QualType DestTy);
86   ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
87     // Unlike for scalars, we don't have to worry about function->ptr demotion
88     // here.
89     return EmitCast(E->getSubExpr(), E->getType());
90   }
91   ComplexPairTy VisitCastExpr(CastExpr *E) {
92     return EmitCast(E->getSubExpr(), E->getType());
93   }
94   ComplexPairTy VisitCallExpr(const CallExpr *E);
95   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
96   ComplexPairTy VisitOverloadExpr(const OverloadExpr *OE);
97 
98   // Operators.
99   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
100                                    bool isInc, bool isPre);
101   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
102     return VisitPrePostIncDec(E, false, false);
103   }
104   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
105     return VisitPrePostIncDec(E, true, false);
106   }
107   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
108     return VisitPrePostIncDec(E, false, true);
109   }
110   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
111     return VisitPrePostIncDec(E, true, true);
112   }
113   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
114   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
115     return Visit(E->getSubExpr());
116   }
117   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
118   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
119   // LNot,SizeOf,AlignOf,Real,Imag never return complex.
120   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
121     return Visit(E->getSubExpr());
122   }
123 
124   struct BinOpInfo {
125     ComplexPairTy LHS;
126     ComplexPairTy RHS;
127     QualType Ty;  // Computation Type.
128   };
129 
130   BinOpInfo EmitBinOps(const BinaryOperator *E);
131   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
132                                    ComplexPairTy (ComplexExprEmitter::*Func)
133                                    (const BinOpInfo &));
134 
135   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
136   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
137   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
138   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
139 
140   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
141     return EmitBinMul(EmitBinOps(E));
142   }
143   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
144     return EmitBinAdd(EmitBinOps(E));
145   }
146   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
147     return EmitBinSub(EmitBinOps(E));
148   }
149   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
150     return EmitBinDiv(EmitBinOps(E));
151   }
152 
153   // Compound assignments.
154   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
155     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
156   }
157   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
158     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
159   }
160   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
161     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
162   }
163   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
164     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
165   }
166 
167   // GCC rejects rem/and/or/xor for integer complex.
168   // Logical and/or always return int, never complex.
169 
170   // No comparisons produce a complex result.
171   ComplexPairTy VisitBinAssign     (const BinaryOperator *E);
172   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
173 
174 
175   ComplexPairTy VisitConditionalOperator(const ConditionalOperator *CO);
176   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
177 };
178 }  // end anonymous namespace.
179 
180 //===----------------------------------------------------------------------===//
181 //                                Utilities
182 //===----------------------------------------------------------------------===//
183 
184 /// EmitLoadOfComplex - Given an RValue reference for a complex, emit code to
185 /// load the real and imaginary pieces, returning them as Real/Imag.
186 ComplexPairTy ComplexExprEmitter::EmitLoadOfComplex(llvm::Value *SrcPtr,
187                                                     bool isVolatile) {
188   llvm::SmallString<64> Name(SrcPtr->getNameStart(),
189                              SrcPtr->getNameStart()+SrcPtr->getNameLen());
190 
191   Name += ".realp";
192   llvm::Value *RealPtr = Builder.CreateStructGEP(SrcPtr, 0, Name.c_str());
193 
194   Name.pop_back();  // .realp -> .real
195   llvm::Value *Real = Builder.CreateLoad(RealPtr, isVolatile, Name.c_str());
196 
197   Name.resize(Name.size()-4); // .real -> .imagp
198   Name += "imagp";
199 
200   llvm::Value *ImagPtr = Builder.CreateStructGEP(SrcPtr, 1, Name.c_str());
201 
202   Name.pop_back();  // .imagp -> .imag
203   llvm::Value *Imag = Builder.CreateLoad(ImagPtr, isVolatile, Name.c_str());
204   return ComplexPairTy(Real, Imag);
205 }
206 
207 /// EmitStoreOfComplex - Store the specified real/imag parts into the
208 /// specified value pointer.
209 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *Ptr,
210                                             bool isVolatile) {
211   llvm::Value *RealPtr = Builder.CreateStructGEP(Ptr, 0, "real");
212   llvm::Value *ImagPtr = Builder.CreateStructGEP(Ptr, 1, "imag");
213 
214   Builder.CreateStore(Val.first, RealPtr, isVolatile);
215   Builder.CreateStore(Val.second, ImagPtr, isVolatile);
216 }
217 
218 
219 
220 //===----------------------------------------------------------------------===//
221 //                            Visitor Methods
222 //===----------------------------------------------------------------------===//
223 
224 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
225   CGF.WarnUnsupported(E, "complex expression");
226   const llvm::Type *EltTy =
227     CGF.ConvertType(E->getType()->getAsComplexType()->getElementType());
228   llvm::Value *U = llvm::UndefValue::get(EltTy);
229   return ComplexPairTy(U, U);
230 }
231 
232 ComplexPairTy ComplexExprEmitter::
233 VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
234   llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
235   return ComplexPairTy(llvm::Constant::getNullValue(Imag->getType()), Imag);
236 }
237 
238 
239 ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
240   return CGF.EmitCallExpr(E).getComplexVal();
241 }
242 
243 ComplexPairTy ComplexExprEmitter::VisitOverloadExpr(const OverloadExpr *E) {
244   return CGF.EmitCallExpr(E->getFn(), E->arg_begin(),
245                           E->getNumArgs(CGF.getContext())).getComplexVal();
246 }
247 
248 ComplexPairTy ComplexExprEmitter::VisitStmtExpr(const StmtExpr *E) {
249   return CGF.EmitCompoundStmt(*E->getSubStmt(), true).getComplexVal();
250 }
251 
252 /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
253 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
254                                                            QualType SrcType,
255                                                            QualType DestType) {
256   // Get the src/dest element type.
257   SrcType = cast<ComplexType>(SrcType.getCanonicalType())->getElementType();
258   DestType = cast<ComplexType>(DestType.getCanonicalType())->getElementType();
259 
260   // C99 6.3.1.6: When a value of complextype is converted to another
261   // complex type, both the real and imaginary parts followthe conversion
262   // rules for the corresponding real types.
263   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType);
264   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType);
265   return Val;
266 }
267 
268 ComplexPairTy ComplexExprEmitter::EmitCast(Expr *Op, QualType DestTy) {
269   // Two cases here: cast from (complex to complex) and (scalar to complex).
270   if (Op->getType()->isComplexType())
271     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
272 
273   // C99 6.3.1.7: When a value of real type is converted to a complex type, the
274   // real part of the complex  result value is determined by the rules of
275   // conversion to the corresponding real type and the imaginary part of the
276   // complex result value is a positive zero or an unsigned zero.
277   llvm::Value *Elt = CGF.EmitScalarExpr(Op);
278 
279   // Convert the input element to the element type of the complex.
280   DestTy = cast<ComplexType>(DestTy.getCanonicalType())->getElementType();
281   Elt = CGF.EmitScalarConversion(Elt, Op->getType(), DestTy);
282 
283   // Return (realval, 0).
284   return ComplexPairTy(Elt, llvm::Constant::getNullValue(Elt->getType()));
285 }
286 
287 ComplexPairTy ComplexExprEmitter::VisitPrePostIncDec(const UnaryOperator *E,
288                                                      bool isInc, bool isPre) {
289   LValue LV = CGF.EmitLValue(E->getSubExpr());
290   // FIXME: Handle volatile!
291   ComplexPairTy InVal = EmitLoadOfComplex(LV.getAddress(), false);
292 
293   uint64_t AmountVal = isInc ? 1 : -1;
294 
295   llvm::Value *NextVal;
296   if (isa<llvm::IntegerType>(InVal.first->getType()))
297     NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal);
298   else if (InVal.first->getType() == llvm::Type::FloatTy)
299     // FIXME: Handle long double.
300     NextVal =
301       llvm::ConstantFP::get(InVal.first->getType(),
302                             llvm::APFloat(static_cast<float>(AmountVal)));
303   else {
304     // FIXME: Handle long double.
305     assert(InVal.first->getType() == llvm::Type::DoubleTy);
306     NextVal =
307       llvm::ConstantFP::get(InVal.first->getType(),
308                             llvm::APFloat(static_cast<double>(AmountVal)));
309   }
310 
311   // Add the inc/dec to the real part.
312   NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
313 
314   ComplexPairTy IncVal(NextVal, InVal.second);
315 
316   // Store the updated result through the lvalue.
317   EmitStoreOfComplex(IncVal, LV.getAddress(), false);  /* FIXME: Volatile */
318 
319   // If this is a postinc, return the value read from memory, otherwise use the
320   // updated value.
321   return isPre ? IncVal : InVal;
322 }
323 
324 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
325   ComplexPairTy Op = Visit(E->getSubExpr());
326   llvm::Value *ResR = Builder.CreateNeg(Op.first,  "neg.r");
327   llvm::Value *ResI = Builder.CreateNeg(Op.second, "neg.i");
328   return ComplexPairTy(ResR, ResI);
329 }
330 
331 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
332   // ~(a+ib) = a + i*-b
333   ComplexPairTy Op = Visit(E->getSubExpr());
334   llvm::Value *ResI = Builder.CreateNeg(Op.second, "conj.i");
335   return ComplexPairTy(Op.first, ResI);
336 }
337 
338 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
339   llvm::Value *ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
340   llvm::Value *ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
341   return ComplexPairTy(ResR, ResI);
342 }
343 
344 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
345   llvm::Value *ResR = Builder.CreateSub(Op.LHS.first,  Op.RHS.first,  "sub.r");
346   llvm::Value *ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
347   return ComplexPairTy(ResR, ResI);
348 }
349 
350 
351 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
352   llvm::Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
353   llvm::Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
354   llvm::Value *ResR  = Builder.CreateSub(ResRl, ResRr, "mul.r");
355 
356   llvm::Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
357   llvm::Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
358   llvm::Value *ResI  = Builder.CreateAdd(ResIl, ResIr, "mul.i");
359   return ComplexPairTy(ResR, ResI);
360 }
361 
362 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
363   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
364   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
365 
366   // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
367   llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr, "tmp"); // a*c
368   llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi, "tmp"); // b*d
369   llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2, "tmp"); // ac+bd
370 
371   llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr, "tmp"); // c*c
372   llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi, "tmp"); // d*d
373   llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5, "tmp"); // cc+dd
374 
375   llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr, "tmp"); // b*c
376   llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi, "tmp"); // a*d
377   llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8, "tmp"); // bc-ad
378 
379   llvm::Value *DSTr, *DSTi;
380   if (Tmp3->getType()->isFloatingPoint()) {
381     DSTr = Builder.CreateFDiv(Tmp3, Tmp6, "tmp");
382     DSTi = Builder.CreateFDiv(Tmp9, Tmp6, "tmp");
383   } else {
384     if (Op.Ty->getAsComplexType()->getElementType()->isUnsignedIntegerType()) {
385       DSTr = Builder.CreateUDiv(Tmp3, Tmp6, "tmp");
386       DSTi = Builder.CreateUDiv(Tmp9, Tmp6, "tmp");
387     } else {
388       DSTr = Builder.CreateSDiv(Tmp3, Tmp6, "tmp");
389       DSTi = Builder.CreateSDiv(Tmp9, Tmp6, "tmp");
390     }
391   }
392 
393   return ComplexPairTy(DSTr, DSTi);
394 }
395 
396 ComplexExprEmitter::BinOpInfo
397 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
398   BinOpInfo Ops;
399   Ops.LHS = Visit(E->getLHS());
400   Ops.RHS = Visit(E->getRHS());
401   Ops.Ty = E->getType();
402   return Ops;
403 }
404 
405 
406 // Compound assignments.
407 ComplexPairTy ComplexExprEmitter::
408 EmitCompoundAssign(const CompoundAssignOperator *E,
409                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
410   QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType();
411 
412   // Load the LHS and RHS operands.
413   LValue LHSLV = CGF.EmitLValue(E->getLHS());
414 
415   BinOpInfo OpInfo;
416   OpInfo.Ty = E->getComputationType();
417 
418   // We know the LHS is a complex lvalue.
419   OpInfo.LHS = EmitLoadOfComplex(LHSLV.getAddress(), false);// FIXME: Volatile.
420   OpInfo.LHS = EmitComplexToComplexCast(OpInfo.LHS, LHSTy, OpInfo.Ty);
421 
422   // It is possible for the RHS to be complex or scalar.
423   OpInfo.RHS = EmitCast(E->getRHS(), OpInfo.Ty);
424 
425   // Expand the binary operator.
426   ComplexPairTy Result = (this->*Func)(OpInfo);
427 
428   // Truncate the result back to the LHS type.
429   Result = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
430 
431   // Store the result value into the LHS lvalue.
432   EmitStoreOfComplex(Result, LHSLV.getAddress(), false); // FIXME: VOLATILE
433   return Result;
434 }
435 
436 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
437   assert(E->getLHS()->getType().getCanonicalType() ==
438          E->getRHS()->getType().getCanonicalType() && "Invalid assignment");
439   // Emit the RHS.
440   ComplexPairTy Val = Visit(E->getRHS());
441 
442   // Compute the address to store into.
443   LValue LHS = CGF.EmitLValue(E->getLHS());
444 
445   // Store into it.
446   // FIXME: Volatility!
447   EmitStoreOfComplex(Val, LHS.getAddress(), false);
448   return Val;
449 }
450 
451 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
452   CGF.EmitStmt(E->getLHS());
453   return Visit(E->getRHS());
454 }
455 
456 ComplexPairTy ComplexExprEmitter::
457 VisitConditionalOperator(const ConditionalOperator *E) {
458   llvm::BasicBlock *LHSBlock = new llvm::BasicBlock("cond.?");
459   llvm::BasicBlock *RHSBlock = new llvm::BasicBlock("cond.:");
460   llvm::BasicBlock *ContBlock = new llvm::BasicBlock("cond.cont");
461 
462   llvm::Value *Cond = CGF.EvaluateExprAsBool(E->getCond());
463   Builder.CreateCondBr(Cond, LHSBlock, RHSBlock);
464 
465   CGF.EmitBlock(LHSBlock);
466 
467   // Handle the GNU extension for missing LHS.
468   assert(E->getLHS() && "Must have LHS for complex value");
469 
470   ComplexPairTy LHS = Visit(E->getLHS());
471   Builder.CreateBr(ContBlock);
472   LHSBlock = Builder.GetInsertBlock();
473 
474   CGF.EmitBlock(RHSBlock);
475 
476   ComplexPairTy RHS = Visit(E->getRHS());
477   Builder.CreateBr(ContBlock);
478   RHSBlock = Builder.GetInsertBlock();
479 
480   CGF.EmitBlock(ContBlock);
481 
482   // Create a PHI node for the real part.
483   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), "cond.r");
484   RealPN->reserveOperandSpace(2);
485   RealPN->addIncoming(LHS.first, LHSBlock);
486   RealPN->addIncoming(RHS.first, RHSBlock);
487 
488   // Create a PHI node for the imaginary part.
489   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), "cond.i");
490   ImagPN->reserveOperandSpace(2);
491   ImagPN->addIncoming(LHS.second, LHSBlock);
492   ImagPN->addIncoming(RHS.second, RHSBlock);
493 
494   return ComplexPairTy(RealPN, ImagPN);
495 }
496 
497 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
498   // Emit the LHS or RHS as appropriate.
499   return Visit(E->isConditionTrue(CGF.getContext()) ? E->getLHS() :E->getRHS());
500 }
501 
502 //===----------------------------------------------------------------------===//
503 //                         Entry Point into this File
504 //===----------------------------------------------------------------------===//
505 
506 /// EmitComplexExpr - Emit the computation of the specified expression of
507 /// complex type, ignoring the result.
508 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E) {
509   assert(E && E->getType()->isComplexType() &&
510          "Invalid complex expression to emit");
511 
512   return ComplexExprEmitter(*this).Visit(const_cast<Expr*>(E));
513 }
514 
515 /// EmitComplexExprIntoAddr - Emit the computation of the specified expression
516 /// of complex type, storing into the specified Value*.
517 void CodeGenFunction::EmitComplexExprIntoAddr(const Expr *E,
518                                               llvm::Value *DestAddr,
519                                               bool DestIsVolatile) {
520   assert(E && E->getType()->isComplexType() &&
521          "Invalid complex expression to emit");
522   ComplexExprEmitter Emitter(*this);
523   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
524   Emitter.EmitStoreOfComplex(Val, DestAddr, DestIsVolatile);
525 }
526 
527 /// LoadComplexFromAddr - Load a complex number from the specified address.
528 ComplexPairTy CodeGenFunction::LoadComplexFromAddr(llvm::Value *SrcAddr,
529                                                    bool SrcIsVolatile) {
530   return ComplexExprEmitter(*this).EmitLoadOfComplex(SrcAddr, SrcIsVolatile);
531 }
532