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/*
* strcmp.c -- strcmp function. On at least some MIPS chips, a strcmp that is
* unrolled twice is faster than the 'optimized' C version in newlib.
*
* Copyright (c) 2001 Red Hat, Inc.
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice is included verbatim in any distributions. No written agreement,
* license, or royalty fee is required for any of the authorized uses.
* Modifications to this software may be copyrighted by their authors
* and need not follow the licensing terms described here, provided that
* the new terms are clearly indicated on the first page of each file where
* they apply. */
#include <stddef.h>
#include <string.h>
#include <stdlib.h>
int
strcmp (const char *s1, const char *s2)
{
unsigned const char *us1 = (unsigned const char *)s1;
unsigned const char *us2 = (unsigned const char *)s2;
int c1a, c1b;
int c2a, c2b;
/* If the pointers aren't both aligned to a 16-byte boundary, do the
comparison byte by byte, so that we don't get an invalid page fault if we
are comparing a string whose null byte is at the last byte on the last
valid page. */
if (((((long)us1) | ((long)us2)) & 1) == 0)
{
c1a = *us1;
for (;;)
{
c1b = *us2;
us1 += 2;
if (c1a == '\0')
goto ret1;
c2a = us1[-1];
if (c1a != c1b)
goto ret1;
c2b = us2[1];
us2 += 2;
if (c2a == '\0')
break;
c1a = *us1;
if (c2a != c2b)
break;
}
return c2a - c2b;
}
else
{
do
{
c1a = *us1++;
c1b = *us2++;
}
while (c1a != '\0' && c1a == c1b);
}
ret1:
return c1a - c1b;
}
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