projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| c891b2df | 1 | /* memcpy - copy a block from source to destination. 64 bit S/390 version. |
| 85dd1003 | 2 | Copyright (C) 2000, 2001, 2003 Free Software Foundation, Inc. |
| 41bdb6e2 | 3 | This file is part of the GNU C Library. |
| 847b055c AJ |
4 | Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com). |
| 5 | ||
| 6 | The GNU C Library is free software; you can redistribute it and/or | |
| 41bdb6e2 AJ |
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. | |
| 847b055c AJ |
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 | |
| 41bdb6e2 | 14 | Lesser General Public License for more details. |
| 847b055c | 15 | |
| 41bdb6e2 AJ |
16 | You should have received a copy of the GNU Lesser General Public |
| 17 | License along with the GNU C Library; if not, write to the Free | |
| 18 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA | |
| 19 | 02111-1307 USA. */ | |
| 847b055c | 20 | |
| ffeac417 | 21 | /* INPUT PARAMETERS |
| c891b2df UD |
22 | %r2 = address of destination memory area |
| 23 | %r3 = address of source memory area | |
| ffeac417 | 24 | %r4 = number of bytes to copy. */ |
| 847b055c AJ |
25 | |
| 26 | #include "sysdep.h" | |
| 27 | #include "asm-syntax.h" | |
| 28 | ||
| 29 | .text | |
| ffeac417 | 30 | ENTRY(memcpy) |
| c891b2df UD |
31 | ltgr %r4,%r4 |
| 32 | jz .L3 | |
| 33 | aghi %r4,-1 # length - 1 | |
| 34 | lgr %r1,%r2 # copy destination address | |
| 3c204435 UD |
35 | srlg %r5,%r4,8 |
| 36 | ltgr %r5,%r5 # < 256 bytes to mvoe ? | |
| ffeac417 | 37 | jz .L1 |
| 79cc0515 | 38 | chi %r5,255 # > 1 MB to move ? |
| 3c204435 | 39 | jh .L4 |
| c891b2df UD |
40 | .L0: mvc 0(256,%r1),0(%r3) # move in 256 byte chunks |
| 41 | la %r1,256(%r1) | |
| 42 | la %r3,256(%r3) | |
| 43 | brctg %r5,.L0 | |
| 44 | .L1: bras %r5,.L2 # setup base pointer for execute | |
| 45 | mvc 0(1,%r1),0(%r3) # instruction for execute | |
| 46 | .L2: ex %r4,0(%r5) # execute mvc with length ((%r4)&255)+1 | |
| 47 | .L3: br %r14 | |
| 3c204435 UD |
48 | # data copies > 1MB are faster with mvcle. |
| 49 | .L4: aghi %r4,1 # length + 1 | |
| 50 | lgr %r5,%r4 # source length | |
| 79cc0515 | 51 | lgr %r4,%r3 # source address |
| 3c204435 UD |
52 | lgr %r3,%r5 # destination length = source length |
| 53 | .L5: mvcle %r2,%r4,0 # thats it, MVCLE is your friend | |
| 54 | jo .L5 | |
| 55 | lgr %r2,%r1 # return destination address | |
| 56 | br %r14 | |
| c891b2df | 57 | END(memcpy) |
| 85dd1003 | 58 | libc_hidden_builtin_def (memcpy) |