[SCM] libav/experimental: arm: Detect 32 bit cpu features on ARMv8 when running on a 64 bit kernel

[siretart at users.alioth.debian.org]

The following commit has been merged in the experimental branch:
commit 7b0c7c9163fe3dd0081696befde28617119d2590
Author: Martin Storsjö <martin at martin.st>
Date:   Mon Jun 23 20:49:21 2014 +0300

    arm: Detect 32 bit cpu features on ARMv8 when running on a 64 bit kernel
    
    When running on a 64 bit kernel, /proc/cpuinfo lists different
    optional features than on 32 bit kernels (because some of them
    are mandatory in the 64 bit implemenations).
    
    The kernel does list the old features properly if they are queried
    via /proc/self/auxv though - however this file is not always readable
    (e.g. on most android systems). The getauxval function could also
    provide the same info as /proc/self/auxv even if this file isn't
    readable, but this function is not always available (and thus would
    need to be loaded with dlsym for compatibility with older android
    versions).
    
    The android cpufeatures library does this slightly differently,
    by assuming that these are available if the "CPU architecture"
    line is >= 8, see [1] for details.
    
    It has been suggested to include the old, non-optional features in
    /proc/cpuinfo as well, but that suggested patch never was merged.
    See [2] for the discussion around this suggestion.
    
    [1] https://android-review.googlesource.com/91380
    [2] http://marc.info/?l=linux-arm-kernel&m=139087240101974
    
    Signed-off-by: Martin Storsjö <martin at martin.st>

diff --git a/libavutil/arm/cpu.c b/libavutil/arm/cpu.c
index 85ea662..8bdaa88 100644
--- a/libavutil/arm/cpu.c
+++ b/libavutil/arm/cpu.c
@@ -90,8 +90,10 @@ static int get_cpuinfo(uint32_t *hwcap)
                 *hwcap |= HWCAP_VFP;
             if (strstr(buf, " vfpv3 "))
                 *hwcap |= HWCAP_VFPv3;
-            if (strstr(buf, " neon "))
+            if (strstr(buf, " neon ") || strstr(buf, " asimd "))
                 *hwcap |= HWCAP_NEON;
+            if (strstr(buf, " fp ")) // Listed on 64 bit ARMv8 kernels
+                *hwcap |= HWCAP_VFP | HWCAP_VFPv3;
             break;
         }
     }

-- 
Libav/FFmpeg packaging