It seems fair to assume that it is always unlikely that IS_ERR will return
true.

This patch changes the gcc-3.4-generated kernel text by ~500 bytes (less) so
it's fair to assume that the compiler is indeed propagating unlikeliness out
of inline functions.

Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 25-akpm/include/linux/err.h |    4 +++-
 1 files changed, 3 insertions(+), 1 deletion(-)

diff -puN include/linux/err.h~is_err-is-unlikely include/linux/err.h
--- 25/include/linux/err.h~is_err-is-unlikely	2004-08-02 20:57:09.468655136 -0700
+++ 25-akpm/include/linux/err.h	2004-08-02 20:57:32.331179504 -0700
@@ -1,6 +1,8 @@
 #ifndef _LINUX_ERR_H
 #define _LINUX_ERR_H
 
+#include <linux/compiler.h>
+
 #include <asm/errno.h>
 
 /*
@@ -23,7 +25,7 @@ static inline long PTR_ERR(const void *p
 
 static inline long IS_ERR(const void *ptr)
 {
-	return (unsigned long)ptr > (unsigned long)-1000L;
+	return unlikely((unsigned long)ptr > (unsigned long)-1000L);
 }
 
 #endif /* _LINUX_ERR_H */
_