1 /* strncpy - copy at most n characters from a string from source to
2 destination. 64 bit S/390 version
3 Copyright (C) 2001-2018 Free Software Foundation, Inc.
4 Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
5 This file is part of the GNU C Library.
7 The GNU C Library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Lesser General Public
9 License as published by the Free Software Foundation; either
10 version 2.1 of the License, or (at your option) any later version.
12 The GNU C Library is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Lesser General Public License for more details.
17 You should have received a copy of the GNU Lesser General Public
18 License along with the GNU C Library; if not, see
19 <http://www.gnu.org/licenses/>. */
22 %r2 = address of destination (dst)
23 %r3 = address of source (src)
24 %r4 = max of bytes to copy. */
26 #include <ifunc-strncpy.h>
28 #include "asm-syntax.h"
30 #if HAVE_STRNCPY_Z900_G5
31 ENTRY(STRNCPY_Z900_G5)
33 stg %r2,48(%r15) # save dst pointer
34 slgr %r2,%r3 # %r3 points to src, %r2+%r3 to dst
36 ngr %r1,%r4 # last 3 bits of # bytes
38 ltgr %r4,%r4 # less than 8 bytes to copy ?
40 bras %r5,.L0 # enter loop & load address of a 0
42 .L0: icmh %r0,8,0(%r3) # first byte
44 icmh %r0,4,1(%r3) # second byte
46 icmh %r0,2,2(%r3) # third byte
48 icmh %r0,1,3(%r3) # fourth byte
50 icm %r0,8,4(%r3) # fifth byte
52 icm %r0,4,5(%r3) # sixth byte
54 icm %r0,2,6(%r3) # seventh byte
56 icm %r0,1,7(%r3) # eigth byte
58 stg %r0,0(%r2,%r3) # store all eight to dest.
69 .L3: icmh %r0,4,0(%r5)
70 .L4: icmh %r0,2,0(%r5)
71 .L5: icmh %r0,1,0(%r5)
76 .L10: stg %r0,0(%r2,%r3)
83 algr %r2,%r3 # start of dst area to be zeroed
87 .L13: mvcle %r2,%r4,0 # pad dst with zeroes
89 .Lexit: lg %r2,48(%r15) # return dst pointer
93 # if ! HAVE_STRNCPY_IFUNC
94 strong_alias (STRNCPY_Z900_G5, strncpy)
97 # if defined SHARED && IS_IN (libc)
98 strong_alias (STRNCPY_Z900_G5, __GI_strncpy)