Re: Is detecting endianness at compile-time unworkable?

[Daniel Shumow <shumow@gmail.com>]

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The change was definitely made for performance.  Removing the if
statements, conditioned upon endianess was an approx 10% improvement, which
was very important to getting this library accepted into git.

Thanks,
Dan


On Mon, Jul 30, 2018 at 11:32 AM, Junio C Hamano <gitster@pobox.com> wrote:

> Junio C Hamano <gitster@pobox.com> writes:
>
> > Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:
> >
> >> And, as an aside, the reason we can't easily make it better ourselves is
> >> because the build process for git.git doesn't have a facility to run
> >> code to detect this type of stuff (the configure script is always
> >> optional). So we can't just run this test ourselves.
> >
> > It won't help those who cross-compile anyway.  I thought we declared
> > "we make a reasonable effort to guess the target endianness from the
> > system header by inspecting usual macros, but will not aim to cover
> > every system on the planet---instead there is a knob to tweak it for
> > those on exotic platforms" last time we discussed this?
>
> Well, having said all that, I do not think I personally mind if
> ./configure learned to include a "compile small program and run it
> to determine byte order on the build machine" as part of "we make a
> reasonable effort" as long as it cleanly excludes cross building
> case (and the result is made overridable just in case we misdetect
> the "cross-ness" of the build).
>
>

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