[vlc-devel] [vlc-commits] vlc_CPU_init: factorize altivec check by using asm input

[Rémi Denis-Courmont]

On Fri, 26 Aug 2011 07:00:14 -0400, Rafaël Carré <rafael.carre at gmail.com>
wrote:
>> >      i_capabilities |= CPU_CAPABILITY_NEON;
>> >  # elif defined (CAN_COMPILE_NEON)
> 
> So here __ARM_NEON__ is not defined and CAN_COMPILE_NEON is
> 
>> > -#  define NEED_RUNTIME_CPU_CHECK 1
>> > -# endif
>> > -
>> > -# ifdef NEED_RUNTIME_CPU_CHECK
>> 
>> WTH is this?
> 
> hm? just look at *all* the other capabilities check in this file.

Why do you think this define does not contain NEON in the name?

> #if defined(XXX)
>     /* assume extension is available */
> #elif defined(CAN_COMPILE_XXX)
>     /* runtime check */
> #endif
> 
>> >  #  if defined (__linux__)
>> >      FILE *info = fopen ("/proc/cpuinfo", "rt");
>> >      if (info != NULL)
>> > @@ -274,11 +270,11 @@ out:
>> >  
>> >               if (strncmp (line, "Features\t:", 10))
>> >                   continue;
>> > -#   if defined (CAN_COMPILE_NEON) && !defined (__ARM_NEON__)
>> > +
>> 
>> And this too???
> 
> "So here __ARM_NEON__ is not defined and CAN_COMPILE_NEON is"

What happens if/when we add ARMv6 SIMD run-time detection?
Where is this documented in the commit log?

-- 
Rémi Denis-Courmont
http://www.remlab.net/