aarch64: implement videodsp.prefetch

8% faster h264 decoding on Apple A7.

1 files changed, 28 insertions, 0 deletions

diff --git a/libavcodec/aarch64/videodsp.S b/libavcodec/aarch64/videodsp.S
new file mode 100644
index 0000000000..7ce5a7ddf6
--- /dev/null
+++ b/libavcodec/aarch64/videodsp.S
@@ -0,0 +1,28 @@
+/*
+ * 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 "libavutil/aarch64/asm.S"
+
+function ff_prefetch_aarch64, export=1
+        subs            w2,  w2,  #2
+        prfm            pldl1strm, [x0]
+        prfm            pldl1strm, [x0,  x1]
+        add             x0,  x0,  x1,  lsl #1
+        b.gt            X(ff_prefetch_aarch64)
+        ret
+endfunc