[PATCH] D113107: Support of expression granularity for _Float16.

[Zahira Ammarguellat via Phabricator via llvm-commits]

zahiraam added inline comments.


================
Comment at: clang/lib/CodeGen/CGExprComplex.cpp:609
+  ComplexPairTy Op;
+  PromotionType = getPromotionType(E->getSubExpr()->getType());
+  if (!PromotionType.isNull())
----------------
rjmccall wrote:
> This is overwriting the argument, so the code below doesn't understand whether it's supposed to be emitting a promoted result or not.  You can test this with something like:
> 
> ```
> cf16 = -cf16;
> ```
> 
> Here the context does not want a promoted result, but you will produce one anyway.
> 
> Because this operator does its own arithmetic, like the binary operators, it needs to follow the same basic logic:
> - remember whether you're supposed to emit a promoted result
> - if not, check whether you should do the arithmetic promoted anyway
> - if you did the arithmetic promoted, but you're not supposed to emit a promoted result, unpromote the result

So something like this:

#define HANDLEUNOP(OP)                                                         \
  Value *VisitUnary##OP(const UnaryOperator *E,                                \
                        QualType PromotionType = QualType()) {		             \
    QualType promotionTy = getPromotionType(E->getSubExpr()->getType());       \
    llvvm::Value *result = **Visit##OP**(E, promotionTy);                                     \
   result = EmitUnpromotion(promotionTy, E, result);
  }
  HANDLEUNOP(Minus)
 HANDLEUNOP(Plus)
 HANDLEUNOP(Imag)
 HANDLEUNOP(Reg)
#undef HANDLEUNOP

Where Visit##* are the bodies taken from the current VisitUnary*?


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D113107/new/

https://reviews.llvm.org/D113107