On Wed, May 01, 2024 at 12:55:25PM -0700, H.J. Lu wrote:
> Since bfloat16 has the same range as float32, _Float16 to bfloat16
> conversion is an extension, not a truncation. Rename trunchfbf2.c
> to extendhfbf2.c to provide __extendhfbf2, instead of __trunchfbf2.
>
> Since _Float16 to bfloat16 conversion never worked from the day one,
> the same libgcc version of __trunchfbf2 is used with __extendhfbf2 so
> that this can be backported to release branches all the way where
> __trunchfbf2 was added.
This is wrong.
First of all, it is ABI incompatible change, we can't do that.
And second, neither _Float16 is a subset of __bf16 nor the other way,
so both extend and trunc names are equally wrong.
Jakub
