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/* memcpy - copy a block from source to destination. 64 bit S/390 version.
Copyright (C) 2012 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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, see
<http://www.gnu.org/licenses/>. */
#include "sysdep.h"
#include "asm-syntax.h"
/* INPUT PARAMETERS
%r2 = address of destination memory area
%r3 = address of source memory area
%r4 = number of bytes to copy. */
.text
#ifdef USE_MULTIARCH
ENTRY(memcpy_z900)
#else
ENTRY(memcpy)
#endif
.machine "z900"
ltgr %r4,%r4
je .L_Z900_4
aghi %r4,-1
srlg %r5,%r4,8
ltgr %r5,%r5
lgr %r1,%r2
jne .L_Z900_13
.L_Z900_3:
larl %r5,.L_Z900_15
ex %r4,0(%r5)
.L_Z900_4:
br %r14
.L_Z900_13:
chi %r5,4096 # Switch to mvcle for copies >1MB
jh memcpy_mvcle
.L_Z900_12:
mvc 0(256,%r1),0(%r3)
la %r1,256(%r1)
la %r3,256(%r3)
brctg %r5,.L_Z900_12
j .L_Z900_3
.L_Z900_15:
mvc 0(1,%r1),0(%r3)
#ifdef USE_MULTIARCH
END(memcpy_z900)
#else
END(memcpy)
libc_hidden_builtin_def (memcpy)
#endif
ENTRY(memcpy_mvcle)
# Using as standalone function will result in unexpected
# results since the length field is incremented by 1 in order to
# compensate the changes already done in the functions above.
aghi %r4,1 # length + 1
lgr %r5,%r4 # source length
lgr %r4,%r3 # source address
lgr %r3,%r5 # destination length = source length
.L_MVCLE_1:
mvcle %r2,%r4,0 # thats it, MVCLE is your friend
jo .L_MVCLE_1
lgr %r2,%r1 # return destination address
br %r14
END(memcpy_mvcle)
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