[FFmpeg-devel] [PATCH] avutil/ppc/cpu: Fix power8 linux detection

[Carl Eugen Hoyos]

2019-01-10 10:45 GMT+01:00, Lauri Kasanen <cand at gmx.com>:
> On Wed, 9 Jan 2019 21:55:30 +0100
> Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>
>> 2019-01-08 10:08 GMT+01:00, Lauri Kasanen <cand at gmx.com>:
>> > The existing code was in no released kernel that I can see. The
>> > corrected
>> > code
>> > was added in 3.9.
>> >
>> > Signed-off-by: Lauri Kasanen <cand at gmx.com>
>> > ---
>> >  libavutil/ppc/cpu.c | 10 +++++-----
>> >  1 file changed, 5 insertions(+), 5 deletions(-)
>> >
>> > diff --git a/libavutil/ppc/cpu.c b/libavutil/ppc/cpu.c
>> > index 7bb7cd8..b022149 100644
>> > --- a/libavutil/ppc/cpu.c
>> > +++ b/libavutil/ppc/cpu.c
>> > @@ -93,13 +93,13 @@ int ff_get_cpu_flags_ppc(void)
>> >                  if (buf[i + 1] & PPC_FEATURE_HAS_VSX)
>> >                      ret |= AV_CPU_FLAG_VSX;
>> >  #endif
>> > -#ifdef PPC_FEATURE_ARCH_2_07
>> > -                if (buf[i + 1] & PPC_FEATURE_HAS_POWER8)
>> > -                    ret |= AV_CPU_FLAG_POWER8;
>> > -#endif
>> >                  if (ret & AV_CPU_FLAG_VSX)
>> >                      av_assert0(ret & AV_CPU_FLAG_ALTIVEC);
>>
>> > -                goto out;
>>
>> This seems like an unrelated change.
>
> It's necessary. HWCAP appears before HWCAP2 in the array, so if the
> code jumps out in HWCAP, it never gets to checking the CAP2 bits like
> power8.

The next line (that I unfortunately cut) is:
} else if (buf[i] == AT_HWCAP2) {
indicating afaict that it is only reached if buf[i] is not equal
to HWCAP.
What do I miss?

Carl Eugen