| /* bcopy -- copy a block from source to destination. S/390 version. |
| This file is part of the GNU C Library. |
| Copyright (C) 2000, 2001 Free Software Foundation, Inc. |
| Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com). |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, write to the Free |
| Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. */ |
| |
| /* INPUT PARAMETERS |
| %r2 = address of source |
| %r3 = address of destination |
| %r4 = number of bytes to copy. */ |
| |
| #include "sysdep.h" |
| #include "asm-syntax.h" |
| |
| .text |
| ENTRY(__bcopy) |
| ltr %r1,%r4 # zero bcopy ? |
| jz .L4 |
| clr %r2,%r3 # check against destructive overlap |
| jnl .L0 |
| alr %r1,%r2 |
| clr %r1,%r3 |
| jh .L7 |
| .L0: ahi %r4,-1 # length - 1 |
| lr %r1,%r4 |
| srl %r1,8 |
| ltr %r1,%r1 # < 256 bytes to move ? |
| jz .L2 |
| chi %r1,255 # > 1MB to move ? |
| jh .L5 |
| .L1: mvc 0(256,%r3),0(%r2) # move in 256 byte chunks |
| la %r2,256(%r2) |
| la %r3,256(%r3) |
| brct %r1,.L1 |
| .L2: bras %r1,.L3 # setup base pointer for execute |
| mvc 0(1,%r3),0(%r2) # instruction for execute |
| .L3: ex %r4,0(%r1) # execute mvc with length ((%r4)&255)+1 |
| .L4: br %r14 |
| |
| # data copies > 1MB are faster with mvcle. |
| .L5: ahi %r4,1 # length + 1 |
| lr %r5,%r4 # source length |
| lr %r4,%r2 # source address |
| lr %r2,%r3 # set destination |
| lr %r3,%r5 # destination length = source length |
| .L6: mvcle %r2,%r4,0 # thats it, MVCLE is your friend |
| jo .L6 |
| br %r14 |
| .L7: # destructive overlay, can not use mvcle |
| lr %r1,%r2 # bcopy is called with source,dest |
| lr %r2,%r3 # memmove with dest,source! Oh, well... |
| lr %r3,%r1 |
| basr %r1,0 |
| .L8: |
| #ifdef PIC |
| al %r1,.L9-.L8(%r1) # get address of global offset table |
| # load address of memmove |
| l %r1,memmove@GOT12(%r1) |
| br %r1 |
| .L9: .long _GLOBAL_OFFSET_TABLE_-.L8 |
| #else |
| al %r1,.L9-.L8(%r1) # load address of memmove |
| br %r1 # jump to memmove |
| .L9: .long memmove-.L8 |
| #endif |
| |
| END(__bcopy) |
| |
| #ifndef NO_WEAK_ALIAS |
| weak_alias (__bcopy, bcopy) |
| #endif |
| |
