1 /* Copyright (C) 1991-2022 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, see
16    <https://www.gnu.org/licenses/>.  */
17 
18 #include <string.h>
19 #include <memcopy.h>
20 
21 #ifndef MEMSET
22 # define MEMSET memset
23 #endif
24 
25 void *
26 inhibit_loop_to_libcall
MEMSET(void * dstpp,int c,size_t len)27 MEMSET (void *dstpp, int c, size_t len)
28 {
29   long int dstp = (long int) dstpp;
30 
31   if (len >= 8)
32     {
33       size_t xlen;
34       op_t cccc;
35 
36       cccc = (unsigned char) c;
37       cccc |= cccc << 8;
38       cccc |= cccc << 16;
39       if (OPSIZ > 4)
40 	/* Do the shift in two steps to avoid warning if long has 32 bits.  */
41 	cccc |= (cccc << 16) << 16;
42 
43       /* There are at least some bytes to set.
44 	 No need to test for LEN == 0 in this alignment loop.  */
45       while (dstp % OPSIZ != 0)
46 	{
47 	  ((byte *) dstp)[0] = c;
48 	  dstp += 1;
49 	  len -= 1;
50 	}
51 
52       /* Write 8 `op_t' per iteration until less than 8 `op_t' remain.  */
53       xlen = len / (OPSIZ * 8);
54       while (xlen > 0)
55 	{
56 	  ((op_t *) dstp)[0] = cccc;
57 	  ((op_t *) dstp)[1] = cccc;
58 	  ((op_t *) dstp)[2] = cccc;
59 	  ((op_t *) dstp)[3] = cccc;
60 	  ((op_t *) dstp)[4] = cccc;
61 	  ((op_t *) dstp)[5] = cccc;
62 	  ((op_t *) dstp)[6] = cccc;
63 	  ((op_t *) dstp)[7] = cccc;
64 	  dstp += 8 * OPSIZ;
65 	  xlen -= 1;
66 	}
67       len %= OPSIZ * 8;
68 
69       /* Write 1 `op_t' per iteration until less than OPSIZ bytes remain.  */
70       xlen = len / OPSIZ;
71       while (xlen > 0)
72 	{
73 	  ((op_t *) dstp)[0] = cccc;
74 	  dstp += OPSIZ;
75 	  xlen -= 1;
76 	}
77       len %= OPSIZ;
78     }
79 
80   /* Write the last few bytes.  */
81   while (len > 0)
82     {
83       ((byte *) dstp)[0] = c;
84       dstp += 1;
85       len -= 1;
86     }
87 
88   return dstpp;
89 }
90 libc_hidden_builtin_def (MEMSET)
91