Re: [PATCH 2/2] gnu: zita-convolver: Drop the '-march=native' optimization.

[ludo@gnu.org (Ludovic Courtès)]

Ricardo Wurmus <rekado@elephly.net> skribis:

> 宋文武 <iyzsong@member.fsf.org> writes:
>
>> Ricardo Wurmus <rekado@elephly.net> writes:
>>
>>>> +              (snippet
>>>> +               ;; Don't optimize for a specific processor architecture.
>>>> +               '(substitute* "libs/Makefile"
>>>> +                  (("^CXXFLAGS \\+= -march=native") "")))
>>>> +              (modules '((guix build utils)))
>>>
>>> Is this to avoid that packages are optimised for the CPU of the build
>>> slave?
>> Yes, using that from hydra will crash guitarix for me.
>> Same as: <https://bugs.archlinux.org/task/36248>.
>
> Guitarix also crashes for me on i686 — and I thought it was something to
> do with my machine or the broken build of eigen.

Eigen is a header-only library, so what matters is the optimization
flags passed when building the software that uses Eigen.

>>> If so, could we instead pass different optimisation flags for
>>> different architectures?  For a convolver I’d prefer to have *some*
>>> optimisation, even if it’s just the greatest common divisor.

It’s likely that zita-convolver has -O2 or similar *in addition* to
-march=native, because the latter is no substitute for the former.

Could you check that in the makefiles?

But yeah, the patch is a good idea anyway.

Thanks,
Ludo’.