[FFmpeg-cvslog] arm: Avoid using the 'setend' instruction on ARMv7 and newer

Martin Storsjö git at videolan.org
Wed Jul 30 20:27:04 CEST 2014


ffmpeg | branch: release/2.2 | Martin Storsjö <martin at martin.st> | Fri Jul  4 18:21:50 2014 +0300| [b8e57113ecba5494d4bf47c29634392ea5fdb17b] | committer: Reinhard Tartler

arm: Avoid using the 'setend' instruction on ARMv7 and newer

This instruction is deprecated on ARMv8, and it is serializing on
some ARMv7 cores as well [1].

[1] http://article.gmane.org/gmane.linux.ports.arm.kernel/339293

CC: libav-stable at libav.org
Signed-off-by: Martin Storsjö <martin at martin.st>
(cherry picked from commit 79fce1ec8abd017593c003917fc123f7119a78d6)
Signed-off-by: Reinhard Tartler <siretart at tauware.de>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=b8e57113ecba5494d4bf47c29634392ea5fdb17b
---

 libavcodec/arm/h264dsp_init_arm.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/libavcodec/arm/h264dsp_init_arm.c b/libavcodec/arm/h264dsp_init_arm.c
index 92658e7..f9712d8 100644
--- a/libavcodec/arm/h264dsp_init_arm.c
+++ b/libavcodec/arm/h264dsp_init_arm.c
@@ -104,8 +104,12 @@ av_cold void ff_h264dsp_init_arm(H264DSPContext *c, const int bit_depth,
 {
     int cpu_flags = av_get_cpu_flags();
 
-    if (have_armv6(cpu_flags))
+    if (have_armv6(cpu_flags) && !(have_vfpv3(cpu_flags) || have_neon(cpu_flags))) {
+        // This function uses the 'setend' instruction which is deprecated
+        // on ARMv8. This instruction is serializing on some ARMv7 cores as
+        // well. Therefore, only use the function on ARMv6.
         c->h264_find_start_code_candidate = ff_h264_find_start_code_candidate_armv6;
+    }
     if (have_neon(cpu_flags))
         h264dsp_init_neon(c, bit_depth, chroma_format_idc);
 }



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