/* Copyright (c) 1994 Cygnus Support. All rights reserved. Redistribution and use in source and binary forms are permitted provided that the above copyright notice and this paragraph are duplicated in all such forms and that any documentation, and/or other materials related to such distribution and use acknowledge that the software was developed at Cygnus Support, Inc. Cygnus Support, Inc. may not be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ /* FUNCTION <>---set an area of memory INDEX memset SYNOPSIS #include void *memset(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 <> returns the value of <[dst]>. PORTABILITY <> is ANSI C. <> requires no supporting OS subroutines. QUICKREF memset ansi pure */ #include #include "local.h" #include #define LBLOCKSIZE (sizeof(long)) #define UNALIGNED(X) ((uintptr_t)X & (LBLOCKSIZE - 1)) #define TOO_SMALL(LEN) ((LEN) < LBLOCKSIZE) #undef memset void * __inhibit_loop_to_libcall memset (void *m, int c, size_t n) { char *s = (char *) m; #if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__) unsigned 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; }