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 #include <algorithm>
22 using namespace clang;
23 using namespace CodeGen;
24 
25 //===----------------------------------------------------------------------===//
26 //                        Complex Expression Emitter
27 //===----------------------------------------------------------------------===//
28 
29 typedef CodeGenFunction::ComplexPairTy ComplexPairTy;
30 
31 /// Return the complex type that we are meant to emit.
32 static const ComplexType *getComplexType(QualType type) {
33   type = type.getCanonicalType();
34   if (const ComplexType *comp = dyn_cast<ComplexType>(type)) {
35     return comp;
36   } else {
37     return cast<ComplexType>(cast<AtomicType>(type)->getValueType());
38   }
39 }
40 
41 namespace  {
42 class ComplexExprEmitter
43   : public StmtVisitor<ComplexExprEmitter, ComplexPairTy> {
44   CodeGenFunction &CGF;
45   CGBuilderTy &Builder;
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), E->getExprLoc());
74   }
75 
76   ComplexPairTy EmitLoadOfLValue(LValue LV, SourceLocation Loc);
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   /// EmitComplexToComplexCast - Emit a cast from scalar value Val to DestType.
86   ComplexPairTy EmitScalarToComplexCast(llvm::Value *Val, QualType SrcType,
87                                         QualType DestType);
88 
89   //===--------------------------------------------------------------------===//
90   //                            Visitor Methods
91   //===--------------------------------------------------------------------===//
92 
93   ComplexPairTy Visit(Expr *E) {
94     return StmtVisitor<ComplexExprEmitter, ComplexPairTy>::Visit(E);
95   }
96 
97   ComplexPairTy VisitStmt(Stmt *S) {
98     S->dump(CGF.getContext().getSourceManager());
99     llvm_unreachable("Stmt can't have complex result type!");
100   }
101   ComplexPairTy VisitExpr(Expr *S);
102   ComplexPairTy VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr());}
103   ComplexPairTy VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
104     return Visit(GE->getResultExpr());
105   }
106   ComplexPairTy VisitImaginaryLiteral(const ImaginaryLiteral *IL);
107   ComplexPairTy
108   VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *PE) {
109     return Visit(PE->getReplacement());
110   }
111 
112   // l-values.
113   ComplexPairTy VisitDeclRefExpr(DeclRefExpr *E) {
114     if (CodeGenFunction::ConstantEmission result = CGF.tryEmitAsConstant(E)) {
115       if (result.isReference())
116         return EmitLoadOfLValue(result.getReferenceLValue(CGF, E),
117                                 E->getExprLoc());
118 
119       llvm::Constant *pair = result.getValue();
120       return ComplexPairTy(pair->getAggregateElement(0U),
121                            pair->getAggregateElement(1U));
122     }
123     return EmitLoadOfLValue(E);
124   }
125   ComplexPairTy VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
126     return EmitLoadOfLValue(E);
127   }
128   ComplexPairTy VisitObjCMessageExpr(ObjCMessageExpr *E) {
129     return CGF.EmitObjCMessageExpr(E).getComplexVal();
130   }
131   ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
132   ComplexPairTy VisitMemberExpr(const Expr *E) { return EmitLoadOfLValue(E); }
133   ComplexPairTy VisitOpaqueValueExpr(OpaqueValueExpr *E) {
134     if (E->isGLValue())
135       return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E), E->getExprLoc());
136     return CGF.getOpaqueRValueMapping(E).getComplexVal();
137   }
138 
139   ComplexPairTy VisitPseudoObjectExpr(PseudoObjectExpr *E) {
140     return CGF.EmitPseudoObjectRValue(E).getComplexVal();
141   }
142 
143   // FIXME: CompoundLiteralExpr
144 
145   ComplexPairTy EmitCast(CastExpr::CastKind CK, Expr *Op, QualType DestTy);
146   ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
147     // Unlike for scalars, we don't have to worry about function->ptr demotion
148     // here.
149     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
150   }
151   ComplexPairTy VisitCastExpr(CastExpr *E) {
152     return EmitCast(E->getCastKind(), E->getSubExpr(), E->getType());
153   }
154   ComplexPairTy VisitCallExpr(const CallExpr *E);
155   ComplexPairTy VisitStmtExpr(const StmtExpr *E);
156 
157   // Operators.
158   ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
159                                    bool isInc, bool isPre) {
160     LValue LV = CGF.EmitLValue(E->getSubExpr());
161     return CGF.EmitComplexPrePostIncDec(E, LV, isInc, isPre);
162   }
163   ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
164     return VisitPrePostIncDec(E, false, false);
165   }
166   ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
167     return VisitPrePostIncDec(E, true, false);
168   }
169   ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
170     return VisitPrePostIncDec(E, false, true);
171   }
172   ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
173     return VisitPrePostIncDec(E, true, true);
174   }
175   ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
176   ComplexPairTy VisitUnaryPlus     (const UnaryOperator *E) {
177     TestAndClearIgnoreReal();
178     TestAndClearIgnoreImag();
179     return Visit(E->getSubExpr());
180   }
181   ComplexPairTy VisitUnaryMinus    (const UnaryOperator *E);
182   ComplexPairTy VisitUnaryNot      (const UnaryOperator *E);
183   // LNot,Real,Imag never return complex.
184   ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
185     return Visit(E->getSubExpr());
186   }
187   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
188     return Visit(DAE->getExpr());
189   }
190   ComplexPairTy VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
191     CodeGenFunction::CXXDefaultInitExprScope Scope(CGF);
192     return Visit(DIE->getExpr());
193   }
194   ComplexPairTy VisitExprWithCleanups(ExprWithCleanups *E) {
195     CGF.enterFullExpression(E);
196     CodeGenFunction::RunCleanupsScope Scope(CGF);
197     return Visit(E->getSubExpr());
198   }
199   ComplexPairTy VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
200     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
201     QualType Elem = E->getType()->castAs<ComplexType>()->getElementType();
202     llvm::Constant *Null = llvm::Constant::getNullValue(CGF.ConvertType(Elem));
203     return ComplexPairTy(Null, Null);
204   }
205   ComplexPairTy VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
206     assert(E->getType()->isAnyComplexType() && "Expected complex type!");
207     QualType Elem = E->getType()->castAs<ComplexType>()->getElementType();
208     llvm::Constant *Null =
209                        llvm::Constant::getNullValue(CGF.ConvertType(Elem));
210     return ComplexPairTy(Null, Null);
211   }
212 
213   struct BinOpInfo {
214     ComplexPairTy LHS;
215     ComplexPairTy RHS;
216     QualType Ty;  // Computation Type.
217   };
218 
219   BinOpInfo EmitBinOps(const BinaryOperator *E);
220   LValue EmitCompoundAssignLValue(const CompoundAssignOperator *E,
221                                   ComplexPairTy (ComplexExprEmitter::*Func)
222                                   (const BinOpInfo &),
223                                   RValue &Val);
224   ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
225                                    ComplexPairTy (ComplexExprEmitter::*Func)
226                                    (const BinOpInfo &));
227 
228   ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
229   ComplexPairTy EmitBinSub(const BinOpInfo &Op);
230   ComplexPairTy EmitBinMul(const BinOpInfo &Op);
231   ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
232 
233   ComplexPairTy EmitComplexBinOpLibCall(StringRef LibCallName,
234                                         const BinOpInfo &Op);
235 
236   ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
237     return EmitBinAdd(EmitBinOps(E));
238   }
239   ComplexPairTy VisitBinSub(const BinaryOperator *E) {
240     return EmitBinSub(EmitBinOps(E));
241   }
242   ComplexPairTy VisitBinMul(const BinaryOperator *E) {
243     return EmitBinMul(EmitBinOps(E));
244   }
245   ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
246     return EmitBinDiv(EmitBinOps(E));
247   }
248 
249   // Compound assignments.
250   ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
251     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
252   }
253   ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
254     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
255   }
256   ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
257     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
258   }
259   ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
260     return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
261   }
262 
263   // GCC rejects rem/and/or/xor for integer complex.
264   // Logical and/or always return int, never complex.
265 
266   // No comparisons produce a complex result.
267 
268   LValue EmitBinAssignLValue(const BinaryOperator *E,
269                              ComplexPairTy &Val);
270   ComplexPairTy VisitBinAssign     (const BinaryOperator *E);
271   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
272 
273 
274   ComplexPairTy
275   VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
276   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
277 
278   ComplexPairTy VisitInitListExpr(InitListExpr *E);
279 
280   ComplexPairTy VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
281     return EmitLoadOfLValue(E);
282   }
283 
284   ComplexPairTy VisitVAArgExpr(VAArgExpr *E);
285 
286   ComplexPairTy VisitAtomicExpr(AtomicExpr *E) {
287     return CGF.EmitAtomicExpr(E).getComplexVal();
288   }
289 };
290 }  // end anonymous namespace.
291 
292 //===----------------------------------------------------------------------===//
293 //                                Utilities
294 //===----------------------------------------------------------------------===//
295 
296 /// EmitLoadOfLValue - Given an RValue reference for a complex, emit code to
297 /// load the real and imaginary pieces, returning them as Real/Imag.
298 ComplexPairTy ComplexExprEmitter::EmitLoadOfLValue(LValue lvalue,
299                                                    SourceLocation loc) {
300   assert(lvalue.isSimple() && "non-simple complex l-value?");
301   if (lvalue.getType()->isAtomicType())
302     return CGF.EmitAtomicLoad(lvalue, loc).getComplexVal();
303 
304   llvm::Value *SrcPtr = lvalue.getAddress();
305   bool isVolatile = lvalue.isVolatileQualified();
306   unsigned AlignR = lvalue.getAlignment().getQuantity();
307   ASTContext &C = CGF.getContext();
308   QualType ComplexTy = lvalue.getType();
309   unsigned ComplexAlign = C.getTypeAlignInChars(ComplexTy).getQuantity();
310   unsigned AlignI = std::min(AlignR, ComplexAlign);
311 
312   llvm::Value *Real=nullptr, *Imag=nullptr;
313 
314   if (!IgnoreReal || isVolatile) {
315     llvm::Value *RealP = Builder.CreateStructGEP(SrcPtr, 0,
316                                                  SrcPtr->getName() + ".realp");
317     Real = Builder.CreateAlignedLoad(RealP, AlignR, isVolatile,
318                                      SrcPtr->getName() + ".real");
319   }
320 
321   if (!IgnoreImag || isVolatile) {
322     llvm::Value *ImagP = Builder.CreateStructGEP(SrcPtr, 1,
323                                                  SrcPtr->getName() + ".imagp");
324     Imag = Builder.CreateAlignedLoad(ImagP, AlignI, isVolatile,
325                                      SrcPtr->getName() + ".imag");
326   }
327   return ComplexPairTy(Real, Imag);
328 }
329 
330 /// EmitStoreOfComplex - Store the specified real/imag parts into the
331 /// specified value pointer.
332 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val,
333                                             LValue lvalue,
334                                             bool isInit) {
335   if (lvalue.getType()->isAtomicType())
336     return CGF.EmitAtomicStore(RValue::getComplex(Val), lvalue, isInit);
337 
338   llvm::Value *Ptr = lvalue.getAddress();
339   llvm::Value *RealPtr = Builder.CreateStructGEP(Ptr, 0, "real");
340   llvm::Value *ImagPtr = Builder.CreateStructGEP(Ptr, 1, "imag");
341   unsigned AlignR = lvalue.getAlignment().getQuantity();
342   ASTContext &C = CGF.getContext();
343   QualType ComplexTy = lvalue.getType();
344   unsigned ComplexAlign = C.getTypeAlignInChars(ComplexTy).getQuantity();
345   unsigned AlignI = std::min(AlignR, ComplexAlign);
346 
347   Builder.CreateAlignedStore(Val.first, RealPtr, AlignR,
348                              lvalue.isVolatileQualified());
349   Builder.CreateAlignedStore(Val.second, ImagPtr, AlignI,
350                              lvalue.isVolatileQualified());
351 }
352 
353 
354 
355 //===----------------------------------------------------------------------===//
356 //                            Visitor Methods
357 //===----------------------------------------------------------------------===//
358 
359 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
360   CGF.ErrorUnsupported(E, "complex expression");
361   llvm::Type *EltTy =
362     CGF.ConvertType(getComplexType(E->getType())->getElementType());
363   llvm::Value *U = llvm::UndefValue::get(EltTy);
364   return ComplexPairTy(U, U);
365 }
366 
367 ComplexPairTy ComplexExprEmitter::
368 VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
369   llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
370   return ComplexPairTy(llvm::Constant::getNullValue(Imag->getType()), Imag);
371 }
372 
373 
374 ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
375   if (E->getCallReturnType()->isReferenceType())
376     return EmitLoadOfLValue(E);
377 
378   return CGF.EmitCallExpr(E).getComplexVal();
379 }
380 
381 ComplexPairTy ComplexExprEmitter::VisitStmtExpr(const StmtExpr *E) {
382   CodeGenFunction::StmtExprEvaluation eval(CGF);
383   llvm::Value *RetAlloca = CGF.EmitCompoundStmt(*E->getSubStmt(), true);
384   assert(RetAlloca && "Expected complex return value");
385   return EmitLoadOfLValue(CGF.MakeAddrLValue(RetAlloca, E->getType()),
386                           E->getExprLoc());
387 }
388 
389 /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
390 ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
391                                                            QualType SrcType,
392                                                            QualType DestType) {
393   // Get the src/dest element type.
394   SrcType = SrcType->castAs<ComplexType>()->getElementType();
395   DestType = DestType->castAs<ComplexType>()->getElementType();
396 
397   // C99 6.3.1.6: When a value of complex type is converted to another
398   // complex type, both the real and imaginary parts follow the conversion
399   // rules for the corresponding real types.
400   Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType);
401   Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType);
402   return Val;
403 }
404 
405 ComplexPairTy ComplexExprEmitter::EmitScalarToComplexCast(llvm::Value *Val,
406                                                           QualType SrcType,
407                                                           QualType DestType) {
408   // Convert the input element to the element type of the complex.
409   DestType = DestType->castAs<ComplexType>()->getElementType();
410   Val = CGF.EmitScalarConversion(Val, SrcType, DestType);
411 
412   // Return (realval, 0).
413   return ComplexPairTy(Val, llvm::Constant::getNullValue(Val->getType()));
414 }
415 
416 ComplexPairTy ComplexExprEmitter::EmitCast(CastExpr::CastKind CK, Expr *Op,
417                                            QualType DestTy) {
418   switch (CK) {
419   case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!");
420 
421   // Atomic to non-atomic casts may be more than a no-op for some platforms and
422   // for some types.
423   case CK_AtomicToNonAtomic:
424   case CK_NonAtomicToAtomic:
425   case CK_NoOp:
426   case CK_LValueToRValue:
427   case CK_UserDefinedConversion:
428     return Visit(Op);
429 
430   case CK_LValueBitCast: {
431     LValue origLV = CGF.EmitLValue(Op);
432     llvm::Value *V = origLV.getAddress();
433     V = Builder.CreateBitCast(V,
434                     CGF.ConvertType(CGF.getContext().getPointerType(DestTy)));
435     return EmitLoadOfLValue(CGF.MakeAddrLValue(V, DestTy,
436                                                origLV.getAlignment()),
437                             Op->getExprLoc());
438   }
439 
440   case CK_BitCast:
441   case CK_BaseToDerived:
442   case CK_DerivedToBase:
443   case CK_UncheckedDerivedToBase:
444   case CK_Dynamic:
445   case CK_ToUnion:
446   case CK_ArrayToPointerDecay:
447   case CK_FunctionToPointerDecay:
448   case CK_NullToPointer:
449   case CK_NullToMemberPointer:
450   case CK_BaseToDerivedMemberPointer:
451   case CK_DerivedToBaseMemberPointer:
452   case CK_MemberPointerToBoolean:
453   case CK_ReinterpretMemberPointer:
454   case CK_ConstructorConversion:
455   case CK_IntegralToPointer:
456   case CK_PointerToIntegral:
457   case CK_PointerToBoolean:
458   case CK_ToVoid:
459   case CK_VectorSplat:
460   case CK_IntegralCast:
461   case CK_IntegralToBoolean:
462   case CK_IntegralToFloating:
463   case CK_FloatingToIntegral:
464   case CK_FloatingToBoolean:
465   case CK_FloatingCast:
466   case CK_CPointerToObjCPointerCast:
467   case CK_BlockPointerToObjCPointerCast:
468   case CK_AnyPointerToBlockPointerCast:
469   case CK_ObjCObjectLValueCast:
470   case CK_FloatingComplexToReal:
471   case CK_FloatingComplexToBoolean:
472   case CK_IntegralComplexToReal:
473   case CK_IntegralComplexToBoolean:
474   case CK_ARCProduceObject:
475   case CK_ARCConsumeObject:
476   case CK_ARCReclaimReturnedObject:
477   case CK_ARCExtendBlockObject:
478   case CK_CopyAndAutoreleaseBlockObject:
479   case CK_BuiltinFnToFnPtr:
480   case CK_ZeroToOCLEvent:
481   case CK_AddressSpaceConversion:
482     llvm_unreachable("invalid cast kind for complex value");
483 
484   case CK_FloatingRealToComplex:
485   case CK_IntegralRealToComplex:
486     return EmitScalarToComplexCast(CGF.EmitScalarExpr(Op),
487                                    Op->getType(), DestTy);
488 
489   case CK_FloatingComplexCast:
490   case CK_FloatingComplexToIntegralComplex:
491   case CK_IntegralComplexCast:
492   case CK_IntegralComplexToFloatingComplex:
493     return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
494   }
495 
496   llvm_unreachable("unknown cast resulting in complex value");
497 }
498 
499 ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
500   TestAndClearIgnoreReal();
501   TestAndClearIgnoreImag();
502   ComplexPairTy Op = Visit(E->getSubExpr());
503 
504   llvm::Value *ResR, *ResI;
505   if (Op.first->getType()->isFloatingPointTy()) {
506     ResR = Builder.CreateFNeg(Op.first,  "neg.r");
507     ResI = Builder.CreateFNeg(Op.second, "neg.i");
508   } else {
509     ResR = Builder.CreateNeg(Op.first,  "neg.r");
510     ResI = Builder.CreateNeg(Op.second, "neg.i");
511   }
512   return ComplexPairTy(ResR, ResI);
513 }
514 
515 ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
516   TestAndClearIgnoreReal();
517   TestAndClearIgnoreImag();
518   // ~(a+ib) = a + i*-b
519   ComplexPairTy Op = Visit(E->getSubExpr());
520   llvm::Value *ResI;
521   if (Op.second->getType()->isFloatingPointTy())
522     ResI = Builder.CreateFNeg(Op.second, "conj.i");
523   else
524     ResI = Builder.CreateNeg(Op.second, "conj.i");
525 
526   return ComplexPairTy(Op.first, ResI);
527 }
528 
529 ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
530   llvm::Value *ResR, *ResI;
531 
532   if (Op.LHS.first->getType()->isFloatingPointTy()) {
533     ResR = Builder.CreateFAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
534     if (Op.LHS.second && Op.RHS.second)
535       ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
536     else
537       ResI = Op.LHS.second ? Op.LHS.second : Op.RHS.second;
538     assert(ResI && "Only one operand may be real!");
539   } else {
540     ResR = Builder.CreateAdd(Op.LHS.first,  Op.RHS.first,  "add.r");
541     assert(Op.LHS.second && Op.RHS.second &&
542            "Both operands of integer complex operators must be complex!");
543     ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
544   }
545   return ComplexPairTy(ResR, ResI);
546 }
547 
548 ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
549   llvm::Value *ResR, *ResI;
550   if (Op.LHS.first->getType()->isFloatingPointTy()) {
551     ResR = Builder.CreateFSub(Op.LHS.first, Op.RHS.first, "sub.r");
552     if (Op.LHS.second && Op.RHS.second)
553       ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
554     else
555       ResI = Op.LHS.second ? Op.LHS.second
556                            : Builder.CreateFNeg(Op.RHS.second, "sub.i");
557     assert(ResI && "Only one operand may be real!");
558   } else {
559     ResR = Builder.CreateSub(Op.LHS.first, Op.RHS.first, "sub.r");
560     assert(Op.LHS.second && Op.RHS.second &&
561            "Both operands of integer complex operators must be complex!");
562     ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
563   }
564   return ComplexPairTy(ResR, ResI);
565 }
566 
567 /// \brief Emit a libcall for a binary operation on complex types.
568 ComplexPairTy ComplexExprEmitter::EmitComplexBinOpLibCall(StringRef LibCallName,
569                                                           const BinOpInfo &Op) {
570   CallArgList Args;
571   Args.add(RValue::get(Op.LHS.first),
572            Op.Ty->castAs<ComplexType>()->getElementType());
573   Args.add(RValue::get(Op.LHS.second),
574            Op.Ty->castAs<ComplexType>()->getElementType());
575   Args.add(RValue::get(Op.RHS.first),
576            Op.Ty->castAs<ComplexType>()->getElementType());
577   Args.add(RValue::get(Op.RHS.second),
578            Op.Ty->castAs<ComplexType>()->getElementType());
579 
580   // We *must* use the full CG function call building logic here because the
581   // complex type has special ABI handling.
582   const CGFunctionInfo &FuncInfo = CGF.CGM.getTypes().arrangeFreeFunctionCall(
583       Op.Ty, Args, FunctionType::ExtInfo(), RequiredArgs::All);
584   llvm::FunctionType *FTy = CGF.CGM.getTypes().GetFunctionType(FuncInfo);
585   llvm::Constant *Func = CGF.CGM.CreateRuntimeFunction(FTy, LibCallName);
586 
587   return CGF.EmitCall(FuncInfo, Func, ReturnValueSlot(), Args).getComplexVal();
588 }
589 
590 // See C11 Annex G.5.1 for the semantics of multiplicative operators on complex
591 // typed values.
592 ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
593   using llvm::Value;
594   Value *ResR, *ResI;
595 
596   if (Op.LHS.first->getType()->isFloatingPointTy()) {
597     // The general formulation is:
598     // (a + ib) * (c + id) = (a * c - b * d) + i(a * d + b * c)
599     //
600     // But we can fold away components which would be zero due to a real
601     // operand according to C11 Annex G.5.1p2.
602     // FIXME: C11 also provides for imaginary types which would allow folding
603     // still more of this within the type system.
604 
605     if (Op.LHS.second && Op.RHS.second) {
606       // If both operands are complex, delegate to a libcall which works to
607       // prevent underflow and overflow.
608       StringRef LibCallName;
609       switch (Op.LHS.first->getType()->getTypeID()) {
610       default:
611         llvm_unreachable("Unsupported floating point type!");
612       case llvm::Type::HalfTyID:
613         return EmitComplexBinOpLibCall("__mulhc3", Op);
614       case llvm::Type::FloatTyID:
615         return EmitComplexBinOpLibCall("__mulsc3", Op);
616       case llvm::Type::DoubleTyID:
617         return EmitComplexBinOpLibCall("__muldc3", Op);
618       case llvm::Type::PPC_FP128TyID:
619         return EmitComplexBinOpLibCall("__multc3", Op);
620       case llvm::Type::X86_FP80TyID:
621         return EmitComplexBinOpLibCall("__mulxc3", Op);
622       }
623     }
624     assert((Op.LHS.second || Op.RHS.second) &&
625            "At least one operand must be complex!");
626 
627     // If either of the operands is a real rather than a complex, the
628     // imaginary component is ignored when computing the real component of the
629     // result.
630     ResR = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
631 
632     ResI = Op.LHS.second
633                ? Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il")
634                : Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
635   } else {
636     assert(Op.LHS.second && Op.RHS.second &&
637            "Both operands of integer complex operators must be complex!");
638     Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
639     Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second, "mul.rr");
640     ResR = Builder.CreateSub(ResRl, ResRr, "mul.r");
641 
642     Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
643     Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
644     ResI = Builder.CreateAdd(ResIl, ResIr, "mul.i");
645   }
646   return ComplexPairTy(ResR, ResI);
647 }
648 
649 // See C11 Annex G.5.1 for the semantics of multiplicative operators on complex
650 // typed values.
651 ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
652   llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
653   llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
654 
655 
656   llvm::Value *DSTr, *DSTi;
657   if (LHSr->getType()->isFloatingPointTy()) {
658     // If we have a complex operand on the RHS, we delegate to a libcall to
659     // handle all of the complexities and minimize underflow/overflow cases.
660     //
661     // FIXME: We would be able to avoid the libcall in many places if we
662     // supported imaginary types in addition to complex types.
663     if (RHSi) {
664       BinOpInfo LibCallOp = Op;
665       // If LHS was a real, supply a null imaginary part.
666       if (!LHSi)
667         LibCallOp.LHS.second = llvm::Constant::getNullValue(LHSr->getType());
668 
669       StringRef LibCallName;
670       switch (LHSr->getType()->getTypeID()) {
671       default:
672         llvm_unreachable("Unsupported floating point type!");
673       case llvm::Type::HalfTyID:
674         return EmitComplexBinOpLibCall("__divhc3", LibCallOp);
675       case llvm::Type::FloatTyID:
676         return EmitComplexBinOpLibCall("__divsc3", LibCallOp);
677       case llvm::Type::DoubleTyID:
678         return EmitComplexBinOpLibCall("__divdc3", LibCallOp);
679       case llvm::Type::PPC_FP128TyID:
680         return EmitComplexBinOpLibCall("__divtc3", LibCallOp);
681       case llvm::Type::X86_FP80TyID:
682         return EmitComplexBinOpLibCall("__divxc3", LibCallOp);
683       }
684     }
685     assert(LHSi && "Can have at most one non-complex operand!");
686 
687     DSTr = Builder.CreateFDiv(LHSr, RHSr);
688     DSTi = Builder.CreateFDiv(LHSi, RHSr);
689   } else {
690     assert(Op.LHS.second && Op.RHS.second &&
691            "Both operands of integer complex operators must be complex!");
692     // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
693     llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr); // a*c
694     llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi); // b*d
695     llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2); // ac+bd
696 
697     llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr); // c*c
698     llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi); // d*d
699     llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5); // cc+dd
700 
701     llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr); // b*c
702     llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi); // a*d
703     llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8); // bc-ad
704 
705     if (Op.Ty->castAs<ComplexType>()->getElementType()->isUnsignedIntegerType()) {
706       DSTr = Builder.CreateUDiv(Tmp3, Tmp6);
707       DSTi = Builder.CreateUDiv(Tmp9, Tmp6);
708     } else {
709       DSTr = Builder.CreateSDiv(Tmp3, Tmp6);
710       DSTi = Builder.CreateSDiv(Tmp9, Tmp6);
711     }
712   }
713 
714   return ComplexPairTy(DSTr, DSTi);
715 }
716 
717 ComplexExprEmitter::BinOpInfo
718 ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
719   TestAndClearIgnoreReal();
720   TestAndClearIgnoreImag();
721   BinOpInfo Ops;
722   if (E->getLHS()->getType()->isRealFloatingType())
723     Ops.LHS = ComplexPairTy(CGF.EmitScalarExpr(E->getLHS()), nullptr);
724   else
725     Ops.LHS = Visit(E->getLHS());
726   if (E->getRHS()->getType()->isRealFloatingType())
727     Ops.RHS = ComplexPairTy(CGF.EmitScalarExpr(E->getRHS()), nullptr);
728   else
729     Ops.RHS = Visit(E->getRHS());
730 
731   Ops.Ty = E->getType();
732   return Ops;
733 }
734 
735 
736 LValue ComplexExprEmitter::
737 EmitCompoundAssignLValue(const CompoundAssignOperator *E,
738           ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&),
739                          RValue &Val) {
740   TestAndClearIgnoreReal();
741   TestAndClearIgnoreImag();
742   QualType LHSTy = E->getLHS()->getType();
743 
744   BinOpInfo OpInfo;
745 
746   // Load the RHS and LHS operands.
747   // __block variables need to have the rhs evaluated first, plus this should
748   // improve codegen a little.
749   OpInfo.Ty = E->getComputationResultType();
750   QualType ComplexElementTy = cast<ComplexType>(OpInfo.Ty)->getElementType();
751 
752   // The RHS should have been converted to the computation type.
753   if (E->getRHS()->getType()->isRealFloatingType()) {
754     assert(
755         CGF.getContext()
756             .hasSameUnqualifiedType(ComplexElementTy, E->getRHS()->getType()));
757     OpInfo.RHS = ComplexPairTy(CGF.EmitScalarExpr(E->getRHS()), nullptr);
758   } else {
759     assert(CGF.getContext()
760                .hasSameUnqualifiedType(OpInfo.Ty, E->getRHS()->getType()));
761     OpInfo.RHS = Visit(E->getRHS());
762   }
763 
764   LValue LHS = CGF.EmitLValue(E->getLHS());
765 
766   // Load from the l-value and convert it.
767   if (LHSTy->isAnyComplexType()) {
768     ComplexPairTy LHSVal = EmitLoadOfLValue(LHS, E->getExprLoc());
769     OpInfo.LHS = EmitComplexToComplexCast(LHSVal, LHSTy, OpInfo.Ty);
770   } else {
771     llvm::Value *LHSVal = CGF.EmitLoadOfScalar(LHS, E->getExprLoc());
772     // For floating point real operands we can directly pass the scalar form
773     // to the binary operator emission and potentially get more efficient code.
774     if (LHSTy->isRealFloatingType()) {
775       if (!CGF.getContext().hasSameUnqualifiedType(ComplexElementTy, LHSTy))
776         LHSVal = CGF.EmitScalarConversion(LHSVal, LHSTy, ComplexElementTy);
777       OpInfo.LHS = ComplexPairTy(LHSVal, nullptr);
778     } else {
779       OpInfo.LHS = EmitScalarToComplexCast(LHSVal, LHSTy, OpInfo.Ty);
780     }
781   }
782 
783   // Expand the binary operator.
784   ComplexPairTy Result = (this->*Func)(OpInfo);
785 
786   // Truncate the result and store it into the LHS lvalue.
787   if (LHSTy->isAnyComplexType()) {
788     ComplexPairTy ResVal = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
789     EmitStoreOfComplex(ResVal, LHS, /*isInit*/ false);
790     Val = RValue::getComplex(ResVal);
791   } else {
792     llvm::Value *ResVal =
793         CGF.EmitComplexToScalarConversion(Result, OpInfo.Ty, LHSTy);
794     CGF.EmitStoreOfScalar(ResVal, LHS, /*isInit*/ false);
795     Val = RValue::get(ResVal);
796   }
797 
798   return LHS;
799 }
800 
801 // Compound assignments.
802 ComplexPairTy ComplexExprEmitter::
803 EmitCompoundAssign(const CompoundAssignOperator *E,
804                    ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
805   RValue Val;
806   LValue LV = EmitCompoundAssignLValue(E, Func, Val);
807 
808   // The result of an assignment in C is the assigned r-value.
809   if (!CGF.getLangOpts().CPlusPlus)
810     return Val.getComplexVal();
811 
812   // If the lvalue is non-volatile, return the computed value of the assignment.
813   if (!LV.isVolatileQualified())
814     return Val.getComplexVal();
815 
816   return EmitLoadOfLValue(LV, E->getExprLoc());
817 }
818 
819 LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
820                                                ComplexPairTy &Val) {
821   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
822                                                  E->getRHS()->getType()) &&
823          "Invalid assignment");
824   TestAndClearIgnoreReal();
825   TestAndClearIgnoreImag();
826 
827   // Emit the RHS.  __block variables need the RHS evaluated first.
828   Val = Visit(E->getRHS());
829 
830   // Compute the address to store into.
831   LValue LHS = CGF.EmitLValue(E->getLHS());
832 
833   // Store the result value into the LHS lvalue.
834   EmitStoreOfComplex(Val, LHS, /*isInit*/ false);
835 
836   return LHS;
837 }
838 
839 ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
840   ComplexPairTy Val;
841   LValue LV = EmitBinAssignLValue(E, Val);
842 
843   // The result of an assignment in C is the assigned r-value.
844   if (!CGF.getLangOpts().CPlusPlus)
845     return Val;
846 
847   // If the lvalue is non-volatile, return the computed value of the assignment.
848   if (!LV.isVolatileQualified())
849     return Val;
850 
851   return EmitLoadOfLValue(LV, E->getExprLoc());
852 }
853 
854 ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
855   CGF.EmitIgnoredExpr(E->getLHS());
856   return Visit(E->getRHS());
857 }
858 
859 ComplexPairTy ComplexExprEmitter::
860 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
861   TestAndClearIgnoreReal();
862   TestAndClearIgnoreImag();
863   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
864   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
865   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
866 
867   // Bind the common expression if necessary.
868   CodeGenFunction::OpaqueValueMapping binding(CGF, E);
869 
870   RegionCounter Cnt = CGF.getPGORegionCounter(E);
871   CodeGenFunction::ConditionalEvaluation eval(CGF);
872   CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock, Cnt.getCount());
873 
874   eval.begin(CGF);
875   CGF.EmitBlock(LHSBlock);
876   Cnt.beginRegion(Builder);
877   ComplexPairTy LHS = Visit(E->getTrueExpr());
878   LHSBlock = Builder.GetInsertBlock();
879   CGF.EmitBranch(ContBlock);
880   eval.end(CGF);
881 
882   eval.begin(CGF);
883   CGF.EmitBlock(RHSBlock);
884   ComplexPairTy RHS = Visit(E->getFalseExpr());
885   RHSBlock = Builder.GetInsertBlock();
886   CGF.EmitBlock(ContBlock);
887   eval.end(CGF);
888 
889   // Create a PHI node for the real part.
890   llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.r");
891   RealPN->addIncoming(LHS.first, LHSBlock);
892   RealPN->addIncoming(RHS.first, RHSBlock);
893 
894   // Create a PHI node for the imaginary part.
895   llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), 2, "cond.i");
896   ImagPN->addIncoming(LHS.second, LHSBlock);
897   ImagPN->addIncoming(RHS.second, RHSBlock);
898 
899   return ComplexPairTy(RealPN, ImagPN);
900 }
901 
902 ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
903   return Visit(E->getChosenSubExpr());
904 }
905 
906 ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) {
907     bool Ignore = TestAndClearIgnoreReal();
908     (void)Ignore;
909     assert (Ignore == false && "init list ignored");
910     Ignore = TestAndClearIgnoreImag();
911     (void)Ignore;
912     assert (Ignore == false && "init list ignored");
913 
914   if (E->getNumInits() == 2) {
915     llvm::Value *Real = CGF.EmitScalarExpr(E->getInit(0));
916     llvm::Value *Imag = CGF.EmitScalarExpr(E->getInit(1));
917     return ComplexPairTy(Real, Imag);
918   } else if (E->getNumInits() == 1) {
919     return Visit(E->getInit(0));
920   }
921 
922   // Empty init list intializes to null
923   assert(E->getNumInits() == 0 && "Unexpected number of inits");
924   QualType Ty = E->getType()->castAs<ComplexType>()->getElementType();
925   llvm::Type* LTy = CGF.ConvertType(Ty);
926   llvm::Value* zeroConstant = llvm::Constant::getNullValue(LTy);
927   return ComplexPairTy(zeroConstant, zeroConstant);
928 }
929 
930 ComplexPairTy ComplexExprEmitter::VisitVAArgExpr(VAArgExpr *E) {
931   llvm::Value *ArgValue = CGF.EmitVAListRef(E->getSubExpr());
932   llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, E->getType());
933 
934   if (!ArgPtr) {
935     CGF.ErrorUnsupported(E, "complex va_arg expression");
936     llvm::Type *EltTy =
937       CGF.ConvertType(E->getType()->castAs<ComplexType>()->getElementType());
938     llvm::Value *U = llvm::UndefValue::get(EltTy);
939     return ComplexPairTy(U, U);
940   }
941 
942   return EmitLoadOfLValue(CGF.MakeNaturalAlignAddrLValue(ArgPtr, E->getType()),
943                           E->getExprLoc());
944 }
945 
946 //===----------------------------------------------------------------------===//
947 //                         Entry Point into this File
948 //===----------------------------------------------------------------------===//
949 
950 /// EmitComplexExpr - Emit the computation of the specified expression of
951 /// complex type, ignoring the result.
952 ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
953                                                bool IgnoreImag) {
954   assert(E && getComplexType(E->getType()) &&
955          "Invalid complex expression to emit");
956 
957   return ComplexExprEmitter(*this, IgnoreReal, IgnoreImag)
958     .Visit(const_cast<Expr*>(E));
959 }
960 
961 void CodeGenFunction::EmitComplexExprIntoLValue(const Expr *E, LValue dest,
962                                                 bool isInit) {
963   assert(E && getComplexType(E->getType()) &&
964          "Invalid complex expression to emit");
965   ComplexExprEmitter Emitter(*this);
966   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
967   Emitter.EmitStoreOfComplex(Val, dest, isInit);
968 }
969 
970 /// EmitStoreOfComplex - Store a complex number into the specified l-value.
971 void CodeGenFunction::EmitStoreOfComplex(ComplexPairTy V, LValue dest,
972                                          bool isInit) {
973   ComplexExprEmitter(*this).EmitStoreOfComplex(V, dest, isInit);
974 }
975 
976 /// EmitLoadOfComplex - Load a complex number from the specified address.
977 ComplexPairTy CodeGenFunction::EmitLoadOfComplex(LValue src,
978                                                  SourceLocation loc) {
979   return ComplexExprEmitter(*this).EmitLoadOfLValue(src, loc);
980 }
981 
982 LValue CodeGenFunction::EmitComplexAssignmentLValue(const BinaryOperator *E) {
983   assert(E->getOpcode() == BO_Assign);
984   ComplexPairTy Val; // ignored
985   return ComplexExprEmitter(*this).EmitBinAssignLValue(E, Val);
986 }
987 
988 typedef ComplexPairTy (ComplexExprEmitter::*CompoundFunc)(
989     const ComplexExprEmitter::BinOpInfo &);
990 
991 static CompoundFunc getComplexOp(BinaryOperatorKind Op) {
992   switch (Op) {
993   case BO_MulAssign: return &ComplexExprEmitter::EmitBinMul;
994   case BO_DivAssign: return &ComplexExprEmitter::EmitBinDiv;
995   case BO_SubAssign: return &ComplexExprEmitter::EmitBinSub;
996   case BO_AddAssign: return &ComplexExprEmitter::EmitBinAdd;
997   default:
998     llvm_unreachable("unexpected complex compound assignment");
999   }
1000 }
1001 
1002 LValue CodeGenFunction::
1003 EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E) {
1004   CompoundFunc Op = getComplexOp(E->getOpcode());
1005   RValue Val;
1006   return ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
1007 }
1008 
1009 LValue CodeGenFunction::
1010 EmitScalarCompooundAssignWithComplex(const CompoundAssignOperator *E,
1011                                      llvm::Value *&Result) {
1012   CompoundFunc Op = getComplexOp(E->getOpcode());
1013   RValue Val;
1014   LValue Ret = ComplexExprEmitter(*this).EmitCompoundAssignLValue(E, Op, Val);
1015   Result = Val.getScalarVal();
1016   return Ret;
1017 }
1018