From fb4cac573ef6dce8d7543b68306566561c2e5725 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Tue, 18 Mar 2014 15:26:39 -0400 Subject: 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 Link: http://lkml.kernel.org/r/1395170800-11059-5-git-send-email-vgoyal@redhat.com Signed-off-by: H. Peter Anvin --- arch/x86/boot/string.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'arch/x86/boot/string.c') diff --git a/arch/x86/boot/string.c b/arch/x86/boot/string.c index 574dedfe2890..5339040ef86e 100644 --- a/arch/x86/boot/string.c +++ b/arch/x86/boot/string.c @@ -14,6 +14,20 @@ #include "boot.h" +/* + * This file gets included in compressed/string.c which might pull in + * string_32.h and which in turn maps memcmp to __builtin_memcmp(). Undo + * that first. + */ +#undef memcmp +int memcmp(const void *s1, const void *s2, size_t len) +{ + u8 diff; + asm("repe; cmpsb; setnz %0" + : "=qm" (diff), "+D" (s1), "+S" (s2), "+c" (len)); + return diff; +} + int strcmp(const char *str1, const char *str2) { const unsigned char *s1 = (const unsigned char *)str1; -- cgit