glibc/sysdeps/s390/bcopy.S

70 lines
2.5 KiB
ArmAsm

/* bcopy -- copy a block from source to destination. For IBM S390
This file is part of the GNU C Library.
Copyright (C) 2000 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 Library General Public License as
published by the Free Software Foundation ; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/*
* R2 = address of source
* R3 = address of destination
* R4 = number of bytes to copy
*/
#include "sysdep.h"
#include "asm-syntax.h"
.text
ENTRY(__bcopy)
clr %r2,%r3 # check against destructive overlap
jnl .L0
lr %r1,%r2
alr %r1,%r4
clr %r1,%r3
jh .L2
.L0:
lr %r5,%r4 # source length
lr %r4,%r2 # source address
sr %r1,%r1 # set pad byte to zero
lr %r2,%r3 # set destination
lr %r3,%r5 # destination length = source length
.L1: mvcle %r2,%r4,0(%r1) # thats it, MVCLE is your friend
jo .L1
br %r14
.L2: # 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
.L3:
#ifdef PIC
al %r1,.L4-.L3(%r1) # get address of global offset table
# load address of memmove
l %r1,memmove@GOT12(%r1)
br %r1
.L4: .long _GLOBAL_OFFSET_TABLE_-.L3
#else
al %r1,.L4-.L3(%r1) # load address of memmove
br %r1 # jump to memmove
.L4: .long memmove-.L3
#endif
END(__bcopy)
#ifndef NO_WEAK_ALIAS
weak_alias (__bcopy, bcopy)
#endif