x86_64: Always use builtin memcpy on gcc 4.3

Andi Kleen · Linus Torvalds · commit aac57f81eb16 · 2007-07-21T18:37:08.000-07:00
Jan asked to always use the builtin memcpy on gcc 4.3 mainline because
it should generate better code than the old macro. Let's try it.

Cc: Jan Hubicka &lt;jh@suse.cz&gt;
Signed-off-by: Andi Kleen &lt;ak@suse.de&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
diff --git a/include/asm-x86_64/string.h b/include/asm-x86_64/string.h
@@ -29,6 +29,9 @@ return (to);
    function. */
 
 #define __HAVE_ARCH_MEMCPY 1
+#if (__GNUC__ == 4 && __GNUC_MINOR__ >= 3) || __GNUC__ > 4
+extern void *memcpy(void *to, const void *from, size_t len);
+#else
 extern void *__memcpy(void *to, const void *from, size_t len); 
 #define memcpy(dst,src,len) \
 	({ size_t __len = (len);				\
@@ -38,7 +41,7 @@ extern void *__memcpy(void *to, const void *from, size_t len);
 	   else							\
 		 __ret = __builtin_memcpy((dst),(src),__len);	\
 	   __ret; }) 
-
+#endif
 
 #define __HAVE_ARCH_MEMSET
 void *memset(void *s, int c, size_t n);
