Branch optimisation in both C (giving hints to gcc - verified using -fprofile-arcs and gcov) and asm files. Biggest effect on coldfire (-c1000: +8%, -c2000: +5%), but ARM also profits a bit (less than 1% on ARM7TDMI, around 1% on ARM1136).

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@19199 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 9 insertions, 0 deletions

diff --git a/apps/codecs/demac/libdemac/demac_config.h b/apps/codecs/demac/libdemac/demac_config.h
index dd3aaa3f9c..986e5376c4 100644
--- a/apps/codecs/demac/libdemac/demac_config.h
+++ b/apps/codecs/demac/libdemac/demac_config.h
@@ -70,6 +70,15 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110, USA
 #define ICODE_ATTR
 #define ICODE_ATTR_DEMAC
 
+/* Use to give gcc hints on which branch is most likely taken */
+#if defined(__GNUC__) && __GNUC__ >= 3
+#define LIKELY(x)   __builtin_expect(!!(x), 1)
+#define UNLIKELY(x) __builtin_expect(!!(x), 0)
+#else
+#define LIKELY(x)   (x)
+#define UNLIKELY(x) (x)
+#endif
+
 #endif /* !ROCKBOX */
 
 /* Defaults */