1/*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Mike Hibler and Chris Torek. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33#include "strings.h" 34#include <sys/types.h> 35 36#define wsize sizeof(u_int) 37#define wmask (wsize - 1) 38 39__attribute__((visibility("hidden"))) 40void 41bzero(void *dst0, size_t length) 42{ 43 return (void)memset(dst0, 0, length); 44} 45 46#define RETURN return (dst0) 47#define VAL c0 48#define WIDEVAL c 49 50__attribute__((visibility("hidden"))) 51void * 52memset(void *dst0, int c0, size_t length) 53{ 54 size_t t; 55 u_int c; 56 u_char *dst; 57 58 dst = dst0; 59 /* 60 * If not enough words, just fill bytes. A length >= 2 words 61 * guarantees that at least one of them is `complete' after 62 * any necessary alignment. For instance: 63 * 64 * |-----------|-----------|-----------| 65 * |00|01|02|03|04|05|06|07|08|09|0A|00| 66 * ^---------------------^ 67 * dst dst+length-1 68 * 69 * but we use a minimum of 3 here since the overhead of the code 70 * to do word writes is substantial. 71 */ 72 if (length < 3 * wsize) { 73 while (length != 0) { 74 *dst++ = VAL; 75 --length; 76 } 77 RETURN; 78 } 79 80 if ((c = (u_char)c0) != 0) { /* Fill the word. */ 81 c = (c << 8) | c; /* u_int is 16 bits. */ 82#if UINT_MAX > 0xffff 83 c = (c << 16) | c; /* u_int is 32 bits. */ 84#endif 85#if UINT_MAX > 0xffffffff 86 c = (c << 32) | c; /* u_int is 64 bits. */ 87#endif 88 } 89 /* Align destination by filling in bytes. */ 90 if ((t = (long)dst & wmask) != 0) { 91 t = wsize - t; 92 length -= t; 93 do { 94 *dst++ = VAL; 95 } while (--t != 0); 96 } 97 98 /* Fill words. Length was >= 2*words so we know t >= 1 here. */ 99 t = length / wsize; 100 do { 101 *(u_int *)dst = WIDEVAL; 102 dst += wsize; 103 } while (--t != 0); 104 105 /* Mop up trailing bytes, if any. */ 106 t = length & wmask; 107 if (t != 0) 108 do { 109 *dst++ = VAL; 110 } while (--t != 0); 111 RETURN; 112} 113