47 lines
1.7 KiB
ArmAsm
47 lines
1.7 KiB
ArmAsm
/* memcpy - copy a block from source to destination. S/390 version.
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Copyright (C) 2000, 2001 Free Software Foundation, Inc.
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Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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/* INPUT PARAMETERS
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%r2 = address of destination memory area
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%r3 = address of source memory area
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%r4 = number of bytes to copy. */
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#include "sysdep.h"
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#include "asm-syntax.h"
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.text
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ENTRY(memcpy)
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ltr %r4,%r4
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jz .L3
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ahi %r4,-1 # length - 1
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lr %r1,%r2 # copy destination address
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lr %r5,%r4
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sra %r5,8
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jz .L1
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.L0: mvc 0(256,%r1),0(%r3) # move in 256 byte chunks
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la %r1,256(%r1)
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la %r3,256(%r3)
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brct %r5,.L0
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.L1: bras %r5,.L2 # setup base pointer for execute
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mvc 0(1,%r1),0(%r3) # instruction for execute
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.L2: ex %r4,0(%r5) # execute mvc with length ((%r4)&255)+1
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.L3: br %r14
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END(memcpy)
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