x86, boot: Move memcmp() into string.h and string.c

Try to treat memcmp() in same way as memcpy() and memset(). Provide a
declaration in boot/string.h and by default user gets a memcmp() which
maps to builtin function.

Move optimized definition of memcmp() in boot/string.c. Now a user can
do #undef memcmp and link against string.c to use optimzied memcmp().

It also simplifies boot/compressed/string.c where we had to redefine
memcmp(). That extra definition is gone now.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Link: http://lkml.kernel.org/r/1395170800-11059-5-git-send-email-vgoyal@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/x86/boot/string.h b/arch/x86/boot/string.h
index 10939d8da2e0..725e820602b1 100644
--- a/arch/x86/boot/string.h
+++ b/arch/x86/boot/string.h
@@ -8,6 +8,7 @@
 
 void *memcpy(void *dst, const void *src, size_t len);
 void *memset(void *dst, int c, size_t len);
+int memcmp(const void *s1, const void *s2, size_t len);
 
 /*
  * Access builtin version by default. If one needs to use optimized version,
@@ -15,5 +16,6 @@ void *memset(void *dst, int c, size_t len);
  */
 #define memcpy(d,s,l) __builtin_memcpy(d,s,l)
 #define memset(d,c,l) __builtin_memset(d,c,l)
+#define memcmp  __builtin_memcmp
 
 #endif /* BOOT_STRING_H */