On Thu, Dec 10, 2015 at 11:05 AM, Janne Grunau <[email protected]> wrote:
> On 2015-12-09 22:54:14 +0100, Janne Grunau wrote:
>> The vector mode was deprecated in ARMv7-A/VFPv3 and various cpu
>> implementations do not support it in hardware. Vector mode code will
>> depending the OS either be emulated in software or result in an illegal
>> instruction on cpus which does not support it. This was not really
>> problem in practice since NEON implementations of the same functions are
>> preferred. It will however become a problem for checkasm which tests
>> every cpu flag separately.
>>
>> Since this is a cpu feature newer cpu do not support anymore the
>> behaviour of this flag differs from the other flags. It can be only
>> activated by runtime cpu feature selection.
>> ---
>>  libavutil/arm/cpu.h                  | 4 ++++
>>  libavutil/cpu.h                      | 1 +
>>  libavcodec/arm/dcadsp_init_arm.c     | 4 ++--
>>  libavcodec/arm/fft_init_arm.c        | 2 +-
>>  libavcodec/arm/fmtconvert_init_arm.c | 2 +-
>>  libavutil/arm/cpu.c                  | 4 ++++
>>  libavutil/cpu.c                      | 2 ++
>>  tests/checkasm/checkasm.c            | 1 +
>>  8 files changed, 16 insertions(+), 4 deletions(-)
>>
>> diff --git a/libavutil/arm/cpu.h b/libavutil/arm/cpu.h
>> index 224409a..ff474b5 100644
>> --- a/libavutil/arm/cpu.h
>> +++ b/libavutil/arm/cpu.h
>> @@ -30,6 +30,10 @@
>>  #define have_vfpv3(flags)   CPUEXT(flags, VFPV3)
>>  #define have_neon(flags)    CPUEXT(flags, NEON)
>>
>> +/* some functions use the VFPv2 vector mode which is deprecated in ARMv7-A
>> + * and might trap on such CPU depending on the OS configuration */
>> +#define have_vfp_vm(flags)   ((flags) & AV_CPU_FLAG_VFP_VM)
>
> this needs a test for HAVE_VFP or have_vfp(flags)
>
> changed locally

Not sure if it's worth adding a changelog entry, but I think it could
be useful to bump minor version.
-- 
Vittorio
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