From 685ca2672e5842fe185c8f12da6bf108fd8f074f Mon Sep 17 00:00:00 2001
From: Nils Wallménius <nils@rockbox.org>
Date: Sun, 29 Nov 2009 15:21:00 +0000
Subject: Use clz instruction to calculate integer logarithms, speeds up
 decoding of one flac 8 sample by 12%.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@23783 a1c6a512-1295-4272-9138-f99709370657
---
 apps/codecs/libffmpegFLAC/SOURCES  | 2 ++
 apps/codecs/libffmpegFLAC/golomb.h | 8 ++++++++
 2 files changed, 10 insertions(+)

(limited to 'apps/codecs')

diff --git a/apps/codecs/libffmpegFLAC/SOURCES b/apps/codecs/libffmpegFLAC/SOURCES
index 688cd3bce7..823a2b7744 100644
--- a/apps/codecs/libffmpegFLAC/SOURCES
+++ b/apps/codecs/libffmpegFLAC/SOURCES
@@ -1,7 +1,9 @@
 bitstream.c
 decoder.c
 shndec.c
+#if !(defined(CPU_ARM) && (ARM_ARCH > 4))
 tables.c
+#endif
 #if defined(CPU_COLDFIRE)
 coldfire.S
 #elif defined(CPU_ARM)
diff --git a/apps/codecs/libffmpegFLAC/golomb.h b/apps/codecs/libffmpegFLAC/golomb.h
index 659ecc1579..11753fc4bb 100644
--- a/apps/codecs/libffmpegFLAC/golomb.h
+++ b/apps/codecs/libffmpegFLAC/golomb.h
@@ -21,6 +21,13 @@
 
 #include <limits.h>
 
+#if (defined(CPU_ARM) && (ARM_ARCH > 4))
+static inline int av_log2(uint32_t v)
+{
+    return 31 - __builtin_clz(v);
+}
+#else
+
 /* From libavutil/common.h */
 extern const uint8_t ff_log2_tab[256];
 
@@ -41,6 +48,7 @@ static inline int av_log2(unsigned int v)
 
     return n;
 }
+#endif
 
 /**
  * @file golomb.h
-- 
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