xref: /openbmc/linux/arch/parisc/lib/memset.c (revision 9cfc5c90)
1 /* Copyright (C) 1991, 1997 Free Software Foundation, Inc.
2    This file is part of the GNU C Library.
3 
4    The GNU C Library is free software; you can redistribute it and/or
5    modify it under the terms of the GNU Lesser General Public
6    License as published by the Free Software Foundation; either
7    version 2.1 of the License, or (at your option) any later version.
8 
9    The GNU C Library is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12    Lesser General Public License for more details.
13 
14    You should have received a copy of the GNU Lesser General Public
15    License along with the GNU C Library; if not, write to the Free
16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17    02111-1307 USA.  */
18 
19 /* Slight modifications for pa-risc linux - Paul Bame <bame@debian.org> */
20 
21 #include <linux/types.h>
22 #include <asm/string.h>
23 
24 #define OPSIZ (BITS_PER_LONG/8)
25 typedef unsigned long op_t;
26 
27 void *
28 memset (void *dstpp, int sc, size_t len)
29 {
30   unsigned int c = sc;
31   long int dstp = (long int) dstpp;
32 
33   if (len >= 8)
34     {
35       size_t xlen;
36       op_t cccc;
37 
38       cccc = (unsigned char) c;
39       cccc |= cccc << 8;
40       cccc |= cccc << 16;
41       if (OPSIZ > 4)
42 	/* Do the shift in two steps to avoid warning if long has 32 bits.  */
43 	cccc |= (cccc << 16) << 16;
44 
45       /* There are at least some bytes to set.
46 	 No need to test for LEN == 0 in this alignment loop.  */
47       while (dstp % OPSIZ != 0)
48 	{
49 	  ((unsigned char *) dstp)[0] = c;
50 	  dstp += 1;
51 	  len -= 1;
52 	}
53 
54       /* Write 8 `op_t' per iteration until less than 8 `op_t' remain.  */
55       xlen = len / (OPSIZ * 8);
56       while (xlen > 0)
57 	{
58 	  ((op_t *) dstp)[0] = cccc;
59 	  ((op_t *) dstp)[1] = cccc;
60 	  ((op_t *) dstp)[2] = cccc;
61 	  ((op_t *) dstp)[3] = cccc;
62 	  ((op_t *) dstp)[4] = cccc;
63 	  ((op_t *) dstp)[5] = cccc;
64 	  ((op_t *) dstp)[6] = cccc;
65 	  ((op_t *) dstp)[7] = cccc;
66 	  dstp += 8 * OPSIZ;
67 	  xlen -= 1;
68 	}
69       len %= OPSIZ * 8;
70 
71       /* Write 1 `op_t' per iteration until less than OPSIZ bytes remain.  */
72       xlen = len / OPSIZ;
73       while (xlen > 0)
74 	{
75 	  ((op_t *) dstp)[0] = cccc;
76 	  dstp += OPSIZ;
77 	  xlen -= 1;
78 	}
79       len %= OPSIZ;
80     }
81 
82   /* Write the last few bytes.  */
83   while (len > 0)
84     {
85       ((unsigned char *) dstp)[0] = c;
86       dstp += 1;
87       len -= 1;
88     }
89 
90   return dstpp;
91 }
92