1 /* @(#)fillbytes.c	1.18 10/08/21 Copyright 1987, 1995-2010 J. Schilling */
2 /*
3  *	fill memory with data
4  *
5  *	Copyright (c) 1987, 1995-2010 J. Schilling
6  */
7 /*
8  * The contents of this file are subject to the terms of the
9  * Common Development and Distribution License, Version 1.0 only
10  * (the "License").  You may not use this file except in compliance
11  * with the License.
12  *
13  * See the file CDDL.Schily.txt in this distribution for details.
14  *
15  * When distributing Covered Code, include this CDDL HEADER in each
16  * file and include the License file CDDL.Schily.txt from this distribution.
17  */
18 
19 #include <schily/standard.h>
20 #include <schily/align.h>
21 #include <schily/types.h>
22 #include <schily/schily.h>
23 
24 #define	DO8(a)	a; a; a; a; a; a; a; a;
25 
26 #define	cval	((char)lval)
27 
28 /*
29  * fillbytes(to, cnt, val) is the same as memset(to, val, cnt)
30  */
31 #ifdef	PROTOTYPES
32 EXPORT char *
33 fillbytes(void *tov, ssize_t cnt, char val)
34 #else
35 EXPORT char *
36 fillbytes(tov, cnt, val)
37 	void	*tov;
38 	ssize_t	cnt;
39 	char	val;
40 #endif
41 {
42 	register char	*to = (char *)tov;
43 	register ssize_t n;
44 	register long	lval;
45 
46 	/*
47 	 * If we change cnt to be unsigned, check for == instead of <=
48 	 */
49 	if ((n = cnt) <= 0)
50 		return (to);
51 
52 	lval = val & 0xFF;
53 
54 	/*
55 	 * Assign byte-wise until properly aligned for a long pointer.
56 	 */
57 	while (--n >= 0 && !laligned(to)) {
58 		*to++ = cval;
59 	}
60 	n++;
61 
62 	if (n >= (ssize_t)(8 * sizeof (long))) {
63 		register ssize_t rem = n % (8 * sizeof (long));
64 
65 		lval |= (lval<<8);
66 		lval |= (lval<<16);
67 #if SIZE_LONG > SIZE_INT
68 		lval |= (lval<<32);
69 #endif
70 
71 		n /= (8 * sizeof (long));
72 		{
73 			register long *tol = (long *)to;
74 
75 			do {
76 				DO8 (*tol++ = lval);
77 			} while (--n > 0);
78 
79 			to = (char *)tol;
80 		}
81 		n = rem;
82 
83 		if (n >= 8) {
84 			n -= 8;
85 			do {
86 				DO8 (*to++ = cval);
87 			} while ((n -= 8) >= 0);
88 			n += 8;
89 		}
90 		if (n > 0) do {
91 			*to++ = cval;
92 		} while (--n > 0);
93 		return (to);
94 	}
95 	if (n > 0) do {
96 		*to++ = cval;
97 	} while (--n > 0);
98 	return (to);
99 }
100