projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| 847b055c AJ |
1 | /* strncpy - copy at most n characters from a string from source to |
| 2 | destination. For IBM S390 | |
| 3 | This file is part of the GNU C Library. | |
| bfff8b1b | 4 | Copyright (C) 2000-2017 Free Software Foundation, Inc. |
| 847b055c AJ |
5 | Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com). |
| 6 | ||
| 41bdb6e2 AJ |
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. | |
| 847b055c AJ |
11 | |
| 12 | The GNU C Library is distributed in the hope that it will be useful, | |
| 41bdb6e2 | 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 847b055c | 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 41bdb6e2 | 15 | Lesser General Public License for more details. |
| 847b055c | 16 | |
| 41bdb6e2 | 17 | You should have received a copy of the GNU Lesser General Public |
| 59ba27a6 PE |
18 | License along with the GNU C Library; if not, see |
| 19 | <http://www.gnu.org/licenses/>. */ | |
| 847b055c AJ |
20 | |
| 21 | /* | |
| 22 | * R2 = address of destination (dst) | |
| 23 | * R3 = address of source (src) | |
| 24 | * R4 = max of bytes to copy | |
| 25 | */ | |
| 26 | ||
| 27 | #include "sysdep.h" | |
| 28 | #include "asm-syntax.h" | |
| 29 | ||
| 30 | ENTRY(strncpy) | |
| 31 | .text | |
| 32 | st %r2,24(%r15) # save dst pointer | |
| 33 | slr %r2,%r3 # %r3 points to src, %r2+%r3 to dst | |
| 34 | lhi %r1,3 | |
| 35 | nr %r1,%r4 # last 2 bits of # bytes | |
| 36 | srl %r4,2 | |
| 37 | ltr %r4,%r4 # less than 4 bytes to copy ? | |
| 38 | jz .L1 | |
| 39 | bras %r5,.L0 # enter loop & load address of a 0 | |
| 40 | .long 0 | |
| 41 | .L0: icm %r0,8,0(%r3) # first byte | |
| 42 | jz .L3 | |
| 43 | icm %r0,4,1(%r3) # second byte | |
| 44 | jz .L4 | |
| 45 | icm %r0,2,2(%r3) # third byte | |
| 46 | jz .L5 | |
| 47 | icm %r0,1,3(%r3) # fourth byte | |
| 48 | jz .L6 | |
| 49 | st %r0,0(%r2,%r3) # store all four to dest. | |
| 50 | la %r3,4(%r3) | |
| 51 | brct %r4,.L0 | |
| 52 | .L1: ltr %r1,%r1 | |
| 53 | jz .Lexit | |
| 54 | .L2: icm %r0,1,0(%r3) | |
| 55 | stc %r0,0(%r2,%r3) | |
| 56 | la %r3,1(%r3) | |
| 57 | jz .L7 | |
| 58 | brct %r1,.L2 | |
| 59 | j .Lexit | |
| 60 | .L3: icm %r0,4,0(%r5) | |
| 61 | .L4: icm %r0,2,0(%r5) | |
| 62 | .L5: icm %r0,1,0(%r5) | |
| 63 | .L6: st %r0,0(%r2,%r3) | |
| 64 | la %r3,4(%r3) | |
| 65 | ahi %r4,-1 | |
| 66 | j .L8 | |
| 67 | .L7: ahi %r1,-1 | |
| 68 | .L8: sll %r4,2 | |
| 69 | alr %r4,%r1 | |
| 70 | alr %r2,%r3 # start of dst area to be zeroed | |
| 71 | lr %r3,%r4 | |
| 72 | slr %r4,%r4 | |
| 73 | slr %r5,%r5 | |
| 74 | .L9: mvcle %r2,%r4,0 # pad dst with zeroes | |
| 75 | jo .L9 | |
| 76 | .Lexit: l %r2,24(%r15) # return dst pointer | |
| 77 | br %r14 | |
| 78 | END(strncpy) | |
| 85dd1003 | 79 | libc_hidden_builtin_def (strncpy) |