151 lines
5.2 KiB
C
151 lines
5.2 KiB
C
/* Copyright (c) 2009 Xilinx, Inc. All rights reserved.
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions are
|
|
met:
|
|
|
|
1. Redistributions source code must retain the above copyright notice,
|
|
this list of conditions and the following disclaimer.
|
|
|
|
2. Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in the
|
|
documentation and/or other materials provided with the distribution.
|
|
|
|
3. Neither the name of Xilinx nor the names of its contributors may be
|
|
used to endorse or promote products derived from this software without
|
|
specific prior written permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS "AS
|
|
IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
|
|
PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
|
|
TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
|
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
|
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
|
|
FUNCTION
|
|
<<strlen>>---character string length
|
|
|
|
INDEX
|
|
strlen
|
|
|
|
SYNOPSIS
|
|
#include <string.h>
|
|
size_t strlen(const char *<[str]>);
|
|
|
|
DESCRIPTION
|
|
The <<strlen>> function works out the length of the string
|
|
starting at <<*<[str]>>> by counting chararacters until it
|
|
reaches a <<NULL>> character.
|
|
|
|
RETURNS
|
|
<<strlen>> returns the character count.
|
|
|
|
PORTABILITY
|
|
<<strlen>> is ANSI C.
|
|
|
|
<<strlen>> requires no supporting OS subroutines.
|
|
|
|
QUICKREF
|
|
strlen ansi pure
|
|
*/
|
|
|
|
#include <_ansi.h>
|
|
#include <string.h>
|
|
#include <limits.h>
|
|
|
|
#define LBLOCKSIZE (sizeof (long))
|
|
#define UNALIGNED(X) ((long)X & (LBLOCKSIZE - 1))
|
|
|
|
#if LONG_MAX == 2147483647L
|
|
#define DETECTNULL(X) (((X) - 0x01010101) & ~(X) & 0x80808080)
|
|
#else
|
|
#if LONG_MAX == 9223372036854775807L
|
|
/* Nonzero if X (a long int) contains a NULL byte. */
|
|
#define DETECTNULL(X) (((X) - 0x0101010101010101) & ~(X) & 0x8080808080808080)
|
|
#else
|
|
#error long int is not a 32bit or 64bit type.
|
|
#endif
|
|
#endif
|
|
|
|
#ifndef DETECTNULL
|
|
#error long int is not a 32bit or 64bit byte
|
|
#endif
|
|
|
|
size_t
|
|
strlen (const char *str)
|
|
{
|
|
|
|
#ifndef HAVE_HW_PCMP
|
|
|
|
#if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__)
|
|
const char *start = str;
|
|
|
|
while (*str)
|
|
str++;
|
|
|
|
return str - start;
|
|
#else
|
|
const char *start = str;
|
|
unsigned long *aligned_addr;
|
|
|
|
if (!UNALIGNED (str))
|
|
{
|
|
/* If the string is word-aligned, we can check for the presence of
|
|
a null in each word-sized block. */
|
|
aligned_addr = (unsigned long*)str;
|
|
while (!DETECTNULL (*aligned_addr))
|
|
aligned_addr++;
|
|
|
|
/* Once a null is detected, we check each byte in that block for a
|
|
precise position of the null. */
|
|
str = (char*)aligned_addr;
|
|
}
|
|
|
|
while (*str)
|
|
str++;
|
|
return str - start;
|
|
#endif /* not PREFER_SIZE_OVER_SPEED */
|
|
|
|
#else
|
|
|
|
#include "mb_endian.h"
|
|
|
|
asm volatile (" \n\
|
|
or r9, r0, r0 /* Index register */ \n\
|
|
check_alignment: \n\
|
|
andi r3, r5, 3 \n\
|
|
bnei r3, align_arg \n\
|
|
len_loop: \n"
|
|
LOAD4BYTES("r3", "r5", "r9")
|
|
" \n\
|
|
pcmpbf r4, r3, r0 \n\
|
|
bnei r4, end_len \n\
|
|
brid len_loop \n\
|
|
addik r9, r9, 4 \n\
|
|
end_len: \n\
|
|
lbu r3, r5, r9 \n\
|
|
beqi r3, done_len \n\
|
|
brid end_len \n\
|
|
addik r9, r9, 1 \n\
|
|
done_len: \n\
|
|
rtsd r15, 8 \n\
|
|
or r3, r0, r9 /* Return len */ \n\
|
|
align_arg: \n\
|
|
rsubik r10, r3, 4 \n\
|
|
align_loop: \n\
|
|
lbu r3, r5, r9 \n\
|
|
beqid r3, done_len \n\
|
|
addik r10, r10, -1 \n\
|
|
bneid r10, align_loop \n\
|
|
addik r9, r9, 1 \n\
|
|
bri len_loop");
|
|
|
|
#endif /* ! HAVE_HW_PCMP */
|
|
}
|