Re: [PATCH] decay vect tests from run to link for pr95401

[Christophe Lyon <christophe.lyon@linaro.org>]

Hi Alexandre,

On Tue, 30 Apr 2024 at 01:31, Alexandre Oliva <oliva@adacore.com> wrote:
>
> On Apr 22, 2024, Richard Biener <richard.guenther@gmail.com> wrote:
>
> >> Regstrapped on x86_64-linux-gnu and ppc64el-linux-gnu.  Also tested with
> >> gcc-13 on ppc64-vx7r2 and ppc-vx7r2.  Ok to install?
>
> > That makes sense.  OK
>
> >> for  gcc/testsuite/ChangeLog
> >>
> >> * lib/target-supports.exp (check_vect_support_and_set_flags):
> >> Decay to link rather than compile.
>
> Alas, linking may fail because of an incompatible libc, as reported by
> Linaro with a link to their issue GNU-1206 (I'm not posting the link to
> the fully-Javascrippled Jira web page; it shows nothing useful, and I
> can't post feedback there) and to
> https://ci.linaro.org/job/tcwg_gnu_embed_check_gcc--master-thumb_m7_hard_eabi-build/10/artifact/artifacts/00-sumfiles/
> (where I could get useful information)
>
> I'm reverting the patch, and I'll see about some alternate approach that
> can accommodate this scenario after I return from LibrePlanet.
>

Indeed, that's another instance of the tricky multilibs configuration issues.
In this case:
- we configure GCC: --disable-multilib --with-mode=thumb
--with-cpu=cortex-m7 --with-float=hard --target=arm-eabi
(we disable multilibs to save build time)
- we run the tests with
qemu/-mthumb/-march=armv7e-m+fp.dp/-mtune=cortex-m7/-mfloat-abi=hard/-mfpu=auto
which matches the GCC configuration flags,
but the vect.exp tests add -mfpu=neon -mfloat-abi=softfp -march=armv7-a
and link fails because the toolchain does not support softfp libs

HTH

Thanks,

Christophe

> --
> Alexandre Oliva, happy hacker            https://FSFLA.org/blogs/lxo/
>    Free Software Activist                   GNU Toolchain Engineer
> More tolerance and less prejudice are key for inclusion and diversity
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