newlib-cygwin/newlib/libc/machine/microblaze/strcpy.c

182 lines
6.0 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
<<strcpy>>---copy string
INDEX
strcpy
SYNOPSIS
#include <string.h>
char *strcpy(char *restrict <[dst]>, const char *restrict <[src]>);
DESCRIPTION
<<strcpy>> copies the string pointed to by <[src]>
(including the terminating null character) to the array
pointed to by <[dst]>.
RETURNS
This function returns the initial value of <[dst]>.
PORTABILITY
<<strcpy>> is ANSI C.
<<strcpy>> requires no supporting OS subroutines.
QUICKREF
strcpy ansi pure
*/
#include <string.h>
#include <limits.h>
/*SUPPRESS 560*/
/*SUPPRESS 530*/
/* Nonzero if either X or Y is not aligned on a "long" boundary. */
#define UNALIGNED(X, Y) \
(((long)X & (sizeof (long) - 1)) | ((long)Y & (sizeof (long) - 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
char*
_DEFUN (strcpy, (dst0, src0),
char *__restrict dst0 _AND
_CONST char *__restrict src0)
{
#ifndef HAVE_HW_PCMP
#if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__)
char *s = dst0;
while (*dst0++ = *src0++)
;
return s;
#else
char *dst = dst0;
_CONST char *src = src0;
long *aligned_dst;
_CONST long *aligned_src;
/* If SRC or DEST is unaligned, then copy bytes. */
if (!UNALIGNED (src, dst))
{
aligned_dst = (long*)dst;
aligned_src = (long*)src;
/* SRC and DEST are both "long int" aligned, try to do "long int"
sized copies. */
while (!DETECTNULL(*aligned_src))
{
*aligned_dst++ = *aligned_src++;
}
dst = (char*)aligned_dst;
src = (char*)aligned_src;
}
while (*dst++ = *src++)
;
return dst0;
#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\
andi r4, r6, 3 \n\
bnei r3, try_align_args \n\
bnei r4, regular_strcpy /* At this point we dont have a choice */ \n\
cpy_loop: \n"
LOAD4BYTES("r3", "r6", "r9")
" \n\
pcmpbf r4, r0, r3 \n\
bnei r4, cpy_bytes /* If r4 != 0, then null present within string */\n"
STORE4BYTES("r3", "r5", "r9")
" \n\
brid cpy_loop \n\
addik r9, r9, 4 \n\
cpy_bytes: \n\
lbu r3, r6, r9 \n\
sb r3, r5, r9 \n\
addik r4, r4, -1 \n\
bneid r4, cpy_bytes \n\
addik r9, r9, 1 /* delay slot */\n\
cpy_null: \n\
rtsd r15, 8 \n\
or r3, r0, r5 /* Return strcpy result */\n\
try_align_args: \n\
xor r7, r4, r3 \n\
bnei r7, regular_strcpy /* cannot align args */\n\
rsubik r10, r3, 4 /* Number of initial bytes to align */\n\
align_loop: \n\
lbu r3, r6, r9 \n\
sb r3, r5, r9 \n\
beqid r3, end_cpy /* Break if we have seen null character */\n\
addik r10, r10, -1 \n\
bneid r10, align_loop \n\
addik r9, r9, 1 \n\
bri cpy_loop \n\
regular_strcpy: \n\
lbu r3, r6, r9 \n\
sb r3, r5, r9 \n\
bneid r3, regular_strcpy \n\
addik r9, r9, 1 \n\
end_cpy: \n\
rtsd r15, 8 \n\
or r3, r0, r5 /* Return strcpy result */");
#endif /* ! HAVE_HW_PCMP */
}