[FFmpeg-cvslog] x86: cpu: Detect Conroe CPUs and their slow shuffle unit

Fiona Glaser git at videolan.org
Tue Jan 31 20:22:22 EET 2017


ffmpeg | branch: master | Fiona Glaser <fiona at x264.com> | Thu Jan 14 10:54:27 2016 +0100| [8e9cd81d291b1010c625b2766058aadf4affb537] | committer: Diego Biurrun

x86: cpu: Detect Conroe CPUs and their slow shuffle unit

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=8e9cd81d291b1010c625b2766058aadf4affb537
---

 libavutil/x86/cpu.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libavutil/x86/cpu.c b/libavutil/x86/cpu.c
index 328ce6d..3b085e7 100644
--- a/libavutil/x86/cpu.c
+++ b/libavutil/x86/cpu.c
@@ -221,6 +221,12 @@ int ff_get_cpu_flags_x86(void)
          * functions on the Atom. */
         if (family == 6 && model == 28)
             rval |= AV_CPU_FLAG_ATOM;
+
+        /* Conroe has a slow shuffle unit. Check the model number to ensure not
+         * to include crippled low-end Penryns and Nehalems that lack SSE4. */
+        if ((rval & AV_CPU_FLAG_SSSE3) && !(rval & AV_CPU_FLAG_SSE4) &&
+            family == 6 && model < 23)
+            rval |= AV_CPU_FLAG_SSSE3SLOW;
     }
 
 #endif /* cpuid */



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