2 * Copyright (c) 1983 Regents of the University of California.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 #if defined(LIBC_SCCS) && !defined(lint)
35 .asciz "@(#)strncpy.s 5.6 (Berkeley) 6/1/90"
36 #endif /* LIBC_SCCS and not lint */
39 * Copy string s2 over top of string s1.
40 * Truncate or null-pad to n bytes.
49 movl
12(ap
),r6 # r6 = n
51 movl
4(ap
),r3 # r3 = s1
52 movl
8(ap
),r1 # r1 = s2
54 movzwl $
65535,r2 # r2 = bytes in first chunk
55 cmpl r6,r2 # r2 = min(bytes in chunk, n);
59 subl2
r2,r6 # update n
60 locc $
0,r2,(r1) # '\0' found?
62 subl2
r2,r1 # back up pointer updated by locc
63 movc3
r2,(r1),(r3) # copy in next piece
64 tstl
r6 # run out of space?
67 3: # copy up to '\0' logic
68 addl2
r0,r6 # r6 = number of null-pad bytes
69 subl2
r0,r2 # r2 = number of bytes to move
70 subl2
r2,r1 # back up pointer updated by locc
71 movc3
r2,(r1),(r3) # copy in last piece
73 movzwl $
65535,r2 # r2 = bytes in first chunk
74 cmpl r6,r2 # r2 = min(bytes in chunk, n);
78 subl2
r2,r6 # update n
79 movc5 $
0,(r3),$
0,r2,(r3)# pad with '\0's
80 tstl
r6 # finished padding?
83 movl
4(ap
),r0 # return s1