virtualenv/FFmpeg
1
0
Fork 0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2025-08-10 06:10:52 +02:00
Code Issues Releases Activity

x86/cpu: set avxslow cpuflag on btver2 CPUs

Browse Source 
They are also slow when using 256 bit wide registers

Reviewed-by: Hendrik Leppkes <h.leppkes@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>
This commit is contained in:
James Almer
2016-02-07 00:04:59 -03:00
parent ba618bde7f
commit be22bd32fe
1 changed files with 4 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
libavutil/x86/cpu.c
View File

@@ -182,13 +182,11 @@ int ff_get_cpu_flags_x86(void)
/* Similar to the above but for AVX functions on AMD processors. /* Similar to the above but for AVX functions on AMD processors.
This is necessary only for functions using YMM registers on Bulldozer This is necessary only for functions using YMM registers on Bulldozer
based CPUs as they lack 256-bits execution units. SSE/AVX functions and Jaguar based CPUs as they lack 256-bits execution units. SSE/AVX
using XMM registers are always faster on them. functions using XMM registers are always faster on them.
AV_CPU_FLAG_AVX and AV_CPU_FLAG_AVXSLOW are both set so that AVX is AV_CPU_FLAG_AVX and AV_CPU_FLAG_AVXSLOW are both set so that AVX is
used unless explicitly disabled by checking AV_CPU_FLAG_AVXSLOW. used unless explicitly disabled by checking AV_CPU_FLAG_AVXSLOW. */
TODO: Confirm if Excavator is affected or not by this once it's if ((family == 0x15 || family == 0x16) && (rval & AV_CPU_FLAG_AVX))
released, and update the check if necessary. Same for btver2. */
if (family == 0x15 && (rval & AV_CPU_FLAG_AVX))
rval |= AV_CPU_FLAG_AVXSLOW; rval |= AV_CPU_FLAG_AVXSLOW;
} }