diff options
Diffstat (limited to 'lib/libutils/isoc/newlib/memset.c')
-rw-r--r-- | lib/libutils/isoc/newlib/memset.c | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/lib/libutils/isoc/newlib/memset.c b/lib/libutils/isoc/newlib/memset.c new file mode 100644 index 0000000..09eca31 --- /dev/null +++ b/lib/libutils/isoc/newlib/memset.c @@ -0,0 +1,128 @@ +/* + * Copyright (c) 1994-2009 Red Hat, 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 of 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 the copyright holder 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 HOLDERS 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 + <<memset>>---set an area of memory + +INDEX + memset + +ANSI_SYNOPSIS + #include <string.h> + void *memset(void *<[dst]>, int <[c]>, size_t <[length]>); + +TRAD_SYNOPSIS + #include <string.h> + void *memset(<[dst]>, <[c]>, <[length]>) + void *<[dst]>; + int <[c]>; + size_t <[length]>; + +DESCRIPTION + This function converts the argument <[c]> into an unsigned + char and fills the first <[length]> characters of the array + pointed to by <[dst]> to the value. + +RETURNS + <<memset>> returns the value of <[dst]>. + +PORTABILITY +<<memset>> is ANSI C. + + <<memset>> requires no supporting OS subroutines. + +QUICKREF + memset ansi pure +*/ + +#include "_ansi.h" +#include <string.h> + +#define LBLOCKSIZE (sizeof(long)) +#define UNALIGNED(X) ((long)X & (LBLOCKSIZE - 1)) +#define TOO_SMALL(LEN) ((LEN) < LBLOCKSIZE) + +_PTR _DEFUN(memset, (m, c, n), _PTR m _AND int c _AND size_t n) +{ + char *s = (char *)m; + +#if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__) + int i; + unsigned long buffer; + unsigned long *aligned_addr; + unsigned int d = c & 0xff; /* To avoid sign extension, copy C to an + unsigned variable. */ + + while (UNALIGNED(s)) { + if (n--) + *s++ = (char)c; + else + return m; + } + + if (!TOO_SMALL(n)) { + /* + * If we get this far, we know that n is large and s is + * word-aligned. + */ + aligned_addr = (unsigned long *)s; + + /* Store D into each char sized location in BUFFER so that + we can set large blocks quickly. */ + buffer = (d << 8) | d; + buffer |= (buffer << 16); + for (i = 32; i < LBLOCKSIZE * 8; i <<= 1) + buffer = (buffer << i) | buffer; + + /* Unroll the loop. */ + while (n >= LBLOCKSIZE * 4) { + *aligned_addr++ = buffer; + *aligned_addr++ = buffer; + *aligned_addr++ = buffer; + *aligned_addr++ = buffer; + n -= 4 * LBLOCKSIZE; + } + + while (n >= LBLOCKSIZE) { + *aligned_addr++ = buffer; + n -= LBLOCKSIZE; + } + /* Pick up the remainder with a bytewise loop. */ + s = (char *)aligned_addr; + } +#endif /* not PREFER_SIZE_OVER_SPEED */ + + while (n--) + *s++ = (char)c; + + return m; +} |