[Mesa-dev] [Mesa-stable] [PATCH] swr: fix -march flag for AVX

[Emil Velikov]

On 10 June 2016 at 20:43, Tim Rowley <timothy.o.rowley at intel.com> wrote:
> Previously used core-avx-i was for ivybridge;
> corei7-avx allows sandybridge.
Which GCC version was required by the previous and which by the
current version ?

> ---
>  src/gallium/drivers/swr/Makefile.am | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/src/gallium/drivers/swr/Makefile.am b/src/gallium/drivers/swr/Makefile.am
> index d211f2e..8156cf2 100644
> --- a/src/gallium/drivers/swr/Makefile.am
> +++ b/src/gallium/drivers/swr/Makefile.am
> @@ -124,7 +124,7 @@ COMMON_LDFLAGS = \
>  lib_LTLIBRARIES = libswrAVX.la libswrAVX2.la
>
>  libswrAVX_la_CXXFLAGS = \
> -       -march=core-avx-i \
> +       -march=corei7-avx \
I'm likely missing something but neither one seems listed in the 5.4
[1] and 6.1 [2] manual. Should we be using one that's officially
supported ?

That aside, we might want to ensure that these are in sync with the
configure ones. One way it to set a variable, AC_SUBST it in configure
and use it in the makefile. Grep for SSE41 for example how we handle
it.

Thanks
Emil

[1] https://gcc.gnu.org/onlinedocs/gcc-5.4.0/gcc/x86-Options.html#x86-Options
[2] https://gcc.gnu.org/onlinedocs/gcc-6.1.0/gcc/x86-Options.html#x86-Options