Add a CPU flag for the Atom processor.

The Atom has SSSE3 support, which is useful in many cases, but sometimes the
SSSE3 version is slower than the SSE2 equivalent on the Atom, but is generally
faster on other processors supporting SSSE3. This flag allows for selectively
disabling certain SSSE3 functions on the Atom.

1 files changed, 10 insertions, 2 deletions

diff --git a/libavutil/x86/cpu.c b/libavutil/x86/cpu.c
index c11956d3c3..4bc56912b5 100644
--- a/libavutil/x86/cpu.c
+++ b/libavutil/x86/cpu.c
@@ -135,8 +135,8 @@ int ff_get_cpu_flags_x86(void)
         }
     }
 
-    if (!strncmp(vendor.c, "GenuineIntel", 12) &&
-        family == 6 && (model == 9 || model == 13 || model == 14)) {
+    if (!strncmp(vendor.c, "GenuineIntel", 12)) {
+        if (family == 6 && (model == 9 || model == 13 || model == 14)) {
         /* 6/9 (pentium-m "banias"), 6/13 (pentium-m "dothan"), and 6/14 (core1 "yonah")
          * theoretically support sse2, but it's usually slower than mmx,
          * so let's just pretend they don't. AV_CPU_FLAG_SSE2 is disabled and
@@ -145,6 +145,14 @@ int ff_get_cpu_flags_x86(void)
          * situation applies for AV_CPU_FLAG_SSE3 and AV_CPU_FLAG_SSE3SLOW. */
         if (rval & AV_CPU_FLAG_SSE2) rval ^= AV_CPU_FLAG_SSE2SLOW|AV_CPU_FLAG_SSE2;
         if (rval & AV_CPU_FLAG_SSE3) rval ^= AV_CPU_FLAG_SSE3SLOW|AV_CPU_FLAG_SSE3;
+        }
+        /* The Atom processor has SSSE3 support, which is useful in many cases,
+         * but sometimes the SSSE3 version is slower than the SSE2 equivalent
+         * on the Atom, but is generally faster on other processors supporting
+         * SSSE3. This flag allows for selectively disabling certain SSSE3
+         * functions on the Atom. */
+        if (family == 6 && model == 28)
+            rval |= AV_CPU_FLAG_ATOM;
     }
 
     return rval;