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

8e9cd81d · Fiona Glaser · Diego Biurrun · 7d7355aa · 8e9cd81d
Commit 8e9cd81d authored Jan 14, 2016 by Fiona Glaser Committed by Diego Biurrun Jul 20, 2016
Hide whitespace changes
Inline Side-by-side

Showing with 6 additions and 0 deletions

cpu.c libavutil/x86/cpu.c +6 -0

No files found.
--- 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 */