[PATCH] Make integer output faster in libgfortran
Thomas Koenig
tkoenig@netcologne.de
Sun Dec 26 16:15:25 GMT 2021
Hi FX,
>> (We could also do something like that for a 32-bit system, but
>> that is another kettle of fish).
>
> We probably wouldn’t get a speed-up that big. Even on 32-bit targets
> (at least common ones), the 64-bit type and its operations (notably
> division) are implemented via CPU instructions, not library calls.
I'll look at this a bit more closely and report :-)
> At this point, the output of integers is probably bound by the
> many layers of indirection of libgfortran's I/O system (which
> are necessary because of the rich I/O formatting allowed by
> the standard).
There are a few things we could do. Getting a LTO-capable version
of libgfortran would be a huge step, because the compiler could
then strip out all of these layers. The speed of
character:: c
write (*,'(A)', advance="no") c
could stand some improvement :-)
Regards
Thomas
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