1*1b191cb5SApple OSS Distributions /*-
2*1b191cb5SApple OSS Distributions * Copyright (c) 1990, 1993
3*1b191cb5SApple OSS Distributions * The Regents of the University of California. All rights reserved.
4*1b191cb5SApple OSS Distributions *
5*1b191cb5SApple OSS Distributions * This code is derived from software contributed to Berkeley by
6*1b191cb5SApple OSS Distributions * Mike Hibler and Chris Torek.
7*1b191cb5SApple OSS Distributions *
8*1b191cb5SApple OSS Distributions * Redistribution and use in source and binary forms, with or without
9*1b191cb5SApple OSS Distributions * modification, are permitted provided that the following conditions
10*1b191cb5SApple OSS Distributions * are met:
11*1b191cb5SApple OSS Distributions * 1. Redistributions of source code must retain the above copyright
12*1b191cb5SApple OSS Distributions * notice, this list of conditions and the following disclaimer.
13*1b191cb5SApple OSS Distributions * 2. Redistributions in binary form must reproduce the above copyright
14*1b191cb5SApple OSS Distributions * notice, this list of conditions and the following disclaimer in the
15*1b191cb5SApple OSS Distributions * documentation and/or other materials provided with the distribution.
16*1b191cb5SApple OSS Distributions * 4. Neither the name of the University nor the names of its contributors
17*1b191cb5SApple OSS Distributions * may be used to endorse or promote products derived from this software
18*1b191cb5SApple OSS Distributions * without specific prior written permission.
19*1b191cb5SApple OSS Distributions *
20*1b191cb5SApple OSS Distributions * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21*1b191cb5SApple OSS Distributions * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22*1b191cb5SApple OSS Distributions * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23*1b191cb5SApple OSS Distributions * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24*1b191cb5SApple OSS Distributions * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25*1b191cb5SApple OSS Distributions * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26*1b191cb5SApple OSS Distributions * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27*1b191cb5SApple OSS Distributions * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28*1b191cb5SApple OSS Distributions * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29*1b191cb5SApple OSS Distributions * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30*1b191cb5SApple OSS Distributions * SUCH DAMAGE.
31*1b191cb5SApple OSS Distributions */
32*1b191cb5SApple OSS Distributions
33*1b191cb5SApple OSS Distributions #include "strings.h"
34*1b191cb5SApple OSS Distributions #include <sys/types.h>
35*1b191cb5SApple OSS Distributions
36*1b191cb5SApple OSS Distributions #define wsize sizeof(u_int)
37*1b191cb5SApple OSS Distributions #define wmask (wsize - 1)
38*1b191cb5SApple OSS Distributions
39*1b191cb5SApple OSS Distributions // n.b. this must be compiled with -fno-builtin or it might get optimized into
40*1b191cb5SApple OSS Distributions // a recursive call to bzero.
41*1b191cb5SApple OSS Distributions __attribute__((visibility("hidden")))
42*1b191cb5SApple OSS Distributions void
_libkernel_bzero(void * dst0,size_t length)43*1b191cb5SApple OSS Distributions _libkernel_bzero(void *dst0, size_t length)
44*1b191cb5SApple OSS Distributions {
45*1b191cb5SApple OSS Distributions return (void)_libkernel_memset(dst0, 0, length);
46*1b191cb5SApple OSS Distributions }
47*1b191cb5SApple OSS Distributions
48*1b191cb5SApple OSS Distributions #define RETURN return (dst0)
49*1b191cb5SApple OSS Distributions #define VAL c0
50*1b191cb5SApple OSS Distributions #define WIDEVAL c
51*1b191cb5SApple OSS Distributions
52*1b191cb5SApple OSS Distributions __attribute__((visibility("hidden")))
53*1b191cb5SApple OSS Distributions void *
_libkernel_memset(void * dst0,int c0,size_t length)54*1b191cb5SApple OSS Distributions _libkernel_memset(void *dst0, int c0, size_t length)
55*1b191cb5SApple OSS Distributions {
56*1b191cb5SApple OSS Distributions size_t t;
57*1b191cb5SApple OSS Distributions u_int c;
58*1b191cb5SApple OSS Distributions u_char *dst;
59*1b191cb5SApple OSS Distributions
60*1b191cb5SApple OSS Distributions dst = dst0;
61*1b191cb5SApple OSS Distributions /*
62*1b191cb5SApple OSS Distributions * If not enough words, just fill bytes. A length >= 2 words
63*1b191cb5SApple OSS Distributions * guarantees that at least one of them is `complete' after
64*1b191cb5SApple OSS Distributions * any necessary alignment. For instance:
65*1b191cb5SApple OSS Distributions *
66*1b191cb5SApple OSS Distributions * |-----------|-----------|-----------|
67*1b191cb5SApple OSS Distributions * |00|01|02|03|04|05|06|07|08|09|0A|00|
68*1b191cb5SApple OSS Distributions * ^---------------------^
69*1b191cb5SApple OSS Distributions * dst dst+length-1
70*1b191cb5SApple OSS Distributions *
71*1b191cb5SApple OSS Distributions * but we use a minimum of 3 here since the overhead of the code
72*1b191cb5SApple OSS Distributions * to do word writes is substantial.
73*1b191cb5SApple OSS Distributions */
74*1b191cb5SApple OSS Distributions if (length < 3 * wsize) {
75*1b191cb5SApple OSS Distributions while (length != 0) {
76*1b191cb5SApple OSS Distributions *dst++ = VAL;
77*1b191cb5SApple OSS Distributions --length;
78*1b191cb5SApple OSS Distributions }
79*1b191cb5SApple OSS Distributions RETURN;
80*1b191cb5SApple OSS Distributions }
81*1b191cb5SApple OSS Distributions
82*1b191cb5SApple OSS Distributions if ((c = (u_char)c0) != 0) { /* Fill the word. */
83*1b191cb5SApple OSS Distributions c = (c << 8) | c; /* u_int is 16 bits. */
84*1b191cb5SApple OSS Distributions #if UINT_MAX > 0xffff
85*1b191cb5SApple OSS Distributions c = (c << 16) | c; /* u_int is 32 bits. */
86*1b191cb5SApple OSS Distributions #endif
87*1b191cb5SApple OSS Distributions #if UINT_MAX > 0xffffffff
88*1b191cb5SApple OSS Distributions c = (c << 32) | c; /* u_int is 64 bits. */
89*1b191cb5SApple OSS Distributions #endif
90*1b191cb5SApple OSS Distributions }
91*1b191cb5SApple OSS Distributions /* Align destination by filling in bytes. */
92*1b191cb5SApple OSS Distributions if ((t = (long)dst & wmask) != 0) {
93*1b191cb5SApple OSS Distributions t = wsize - t;
94*1b191cb5SApple OSS Distributions length -= t;
95*1b191cb5SApple OSS Distributions do {
96*1b191cb5SApple OSS Distributions *dst++ = VAL;
97*1b191cb5SApple OSS Distributions } while (--t != 0);
98*1b191cb5SApple OSS Distributions }
99*1b191cb5SApple OSS Distributions
100*1b191cb5SApple OSS Distributions /* Fill words. Length was >= 2*words so we know t >= 1 here. */
101*1b191cb5SApple OSS Distributions t = length / wsize;
102*1b191cb5SApple OSS Distributions do {
103*1b191cb5SApple OSS Distributions *(u_int *)dst = WIDEVAL;
104*1b191cb5SApple OSS Distributions dst += wsize;
105*1b191cb5SApple OSS Distributions } while (--t != 0);
106*1b191cb5SApple OSS Distributions
107*1b191cb5SApple OSS Distributions /* Mop up trailing bytes, if any. */
108*1b191cb5SApple OSS Distributions t = length & wmask;
109*1b191cb5SApple OSS Distributions if (t != 0) {
110*1b191cb5SApple OSS Distributions do {
111*1b191cb5SApple OSS Distributions *dst++ = VAL;
112*1b191cb5SApple OSS Distributions } while (--t != 0);
113*1b191cb5SApple OSS Distributions }
114*1b191cb5SApple OSS Distributions RETURN;
115*1b191cb5SApple OSS Distributions }
116