1 | /* strncpy - copy at most n characters from a string from source to |
2 | destination. 64 bit S/390 version |
3 | Copyright (C) 2001-2024 Free Software Foundation, Inc. |
4 | This file is part of the GNU C Library. |
5 | |
6 | The GNU C Library is free software; you can redistribute it and/or |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either |
9 | version 2.1 of the License, or (at your option) any later version. |
10 | |
11 | The GNU C Library is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
14 | Lesser General Public License for more details. |
15 | |
16 | You should have received a copy of the GNU Lesser General Public |
17 | License along with the GNU C Library; if not, see |
18 | <https://www.gnu.org/licenses/>. */ |
19 | |
20 | /* INPUT PARAMETERS |
21 | %r2 = address of destination (dst) |
22 | %r3 = address of source (src) |
23 | %r4 = max of bytes to copy. */ |
24 | |
25 | #include <ifunc-strncpy.h> |
26 | #include "sysdep.h" |
27 | #include "asm-syntax.h" |
28 | |
29 | #if HAVE_STRNCPY_Z900_G5 |
30 | ENTRY(STRNCPY_Z900_G5) |
31 | .text |
32 | stg %r2,48(%r15) # save dst pointer |
33 | slgr %r2,%r3 # %r3 points to src, %r2+%r3 to dst |
34 | lghi %r1,7 |
35 | ngr %r1,%r4 # last 3 bits of # bytes |
36 | srlg %r4,%r4,3 |
37 | ltgr %r4,%r4 # less than 8 bytes to copy ? |
38 | jz .L1 |
39 | bras %r5,.L0 # enter loop & load address of a 0 |
40 | .long 0 |
41 | .L0: icmh %r0,8,0(%r3) # first byte |
42 | jz .L3 |
43 | icmh %r0,4,1(%r3) # second byte |
44 | jz .L4 |
45 | icmh %r0,2,2(%r3) # third byte |
46 | jz .L5 |
47 | icmh %r0,1,3(%r3) # fourth byte |
48 | jz .L6 |
49 | icm %r0,8,4(%r3) # fifth byte |
50 | jz .L7 |
51 | icm %r0,4,5(%r3) # sixth byte |
52 | jz .L8 |
53 | icm %r0,2,6(%r3) # seventh byte |
54 | jz .L9 |
55 | icm %r0,1,7(%r3) # eighth byte |
56 | jz .L10 |
57 | stg %r0,0(%r2,%r3) # store all eight to dest. |
58 | la %r3,8(%r3) |
59 | brct %r4,.L0 |
60 | .L1: ltgr %r1,%r1 |
61 | jz .Lexit |
62 | .L2: icm %r0,1,0(%r3) |
63 | stc %r0,0(%r2,%r3) |
64 | la %r3,1(%r3) |
65 | jz .L11 |
66 | brct %r1,.L2 |
67 | j .Lexit |
68 | .L3: icmh %r0,4,0(%r5) |
69 | .L4: icmh %r0,2,0(%r5) |
70 | .L5: icmh %r0,1,0(%r5) |
71 | .L6: icm %r0,8,0(%r5) |
72 | .L7: icm %r0,4,0(%r5) |
73 | .L8: icm %r0,2,0(%r5) |
74 | .L9: icm %r0,1,0(%r5) |
75 | .L10: stg %r0,0(%r2,%r3) |
76 | la %r3,8(%r3) |
77 | aghi %r4,-1 |
78 | j .L12 |
79 | .L11: aghi %r1,-1 |
80 | .L12: sllg %r4,%r4,3 |
81 | algr %r4,%r1 |
82 | algr %r2,%r3 # start of dst area to be zeroed |
83 | lgr %r3,%r4 |
84 | slgr %r4,%r4 |
85 | slgr %r5,%r5 |
86 | .L13: mvcle %r2,%r4,0 # pad dst with zeroes |
87 | jo .L13 |
88 | .Lexit: lg %r2,48(%r15) # return dst pointer |
89 | br %r14 |
90 | END(STRNCPY_Z900_G5) |
91 | |
92 | # if ! HAVE_STRNCPY_IFUNC |
93 | strong_alias (STRNCPY_Z900_G5, strncpy) |
94 | # endif |
95 | |
96 | # if defined SHARED && IS_IN (libc) |
97 | strong_alias (STRNCPY_Z900_G5, __GI_strncpy) |
98 | # endif |
99 | #endif |
100 | |