ARM: ac3dsp: optimised update_bap_counts()

Signed-off-by: Mans Rullgard <mans@mansr.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/libavcodec/arm/ac3dsp_arm.S b/libavcodec/arm/ac3dsp_arm.S
new file mode 100644
index 0000000000..545714cff1
--- /dev/null
+++ b/libavcodec/arm/ac3dsp_arm.S
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2011 Mans Rullgard <mans@mansr.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 "asm.S"
+
+function ff_ac3_update_bap_counts_arm, export=1
+        push            {lr}
+        ldrb            lr,  [r1], #1
+1:
+        lsl             r3,  lr,  #1
+        ldrh            r12, [r0, r3]
+        subs            r2,  r2,  #1
+        ldrbgt          lr,  [r1], #1
+        add             r12, r12, #1
+        strh            r12, [r0, r3]
+        bgt             1b
+        pop             {pc}
+endfunc