SBR DSP x86: implement SSE sbr_sum_square_sse

The 32bits targets have been compiled with -mfpmath=sse for proper reference.
sbr_sum_square C  /32bits: 82c (unrolled)/102c
               C  /64bits: 69c (unrolled)/82c
               SSE/32bits: 42c
               SSE/64bits: 31c

Use of SSE4.1 dpps to perform the final sum is slower.
Not unrolling to perform 8 operations in a loop yields 10 more cycles.

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/libavcodec/x86/sbrdsp_init.c b/libavcodec/x86/sbrdsp_init.c
new file mode 100644
index 0000000000..313f492054
--- /dev/null
+++ b/libavcodec/x86/sbrdsp_init.c
@@ -0,0 +1,37 @@
+/*
+ * AAC Spectral Band Replication decoding functions
+ * Copyright (c) 2012 Christophe Gisquet <christophe.gisquet@gmail.com>
+ *
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "config.h"
+#include "libavutil/cpu.h"
+#include "libavcodec/sbrdsp.h"
+
+float ff_sbr_sum_square_sse(float (*x)[2], int n);
+
+void ff_sbrdsp_init_x86(SBRDSPContext *s)
+{
+    if (HAVE_YASM) {
+        int mm_flags = av_get_cpu_flags();
+
+        if (mm_flags & AV_CPU_FLAG_SSE) {
+            s->sum_square = ff_sbr_sum_square_sse;
+        }
+    }
+}