https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126016
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |rguenth at gcc dot gnu.org
--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
> As a side-note (but existing pattern before looks the same), I wonder if
> there's any two FP formats X and Y with TYPE_PRECISION (X) > TYPE_PRECISION
> (Y)
> where "extending" from Y to X can involve rounding, thus not all values in Y
> are exactly representable in X? What about normalization to NaNs or Infs or
> denormals?
Is what I asked (being not exactly sure, possibly eyeing IBM double double
and/or x87 80bit FP). GCC supports more than just IEEE FP formats (not to
mention
BF16, FP16 and others).
So, can we generally assume FP widening operations are exact?
