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ffeac417 1/* bcopy -- copy a block from source to destination. 64 bit S/390 version.
847b055c 2 This file is part of the GNU C Library.
d4697bc9 3 Copyright (C) 2000-2014 Free Software Foundation, Inc.
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4 Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
5
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6 The GNU C Library is free software; you can redistribute it and/or
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.
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10
11 The GNU C Library is distributed in the hope that it will be useful,
41bdb6e2 12 but WITHOUT ANY WARRANTY; without even the implied warranty of
847b055c 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
41bdb6e2 14 Lesser General Public License for more details.
847b055c 15
41bdb6e2 16 You should have received a copy of the GNU Lesser General Public
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17 License along with the GNU C Library; if not, see
18 <http://www.gnu.org/licenses/>. */
847b055c 19
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20/* INPUT PARAMETERS
21 %r2 = address of source
22 %r3 = address of destination
23 %r4 = number of bytes to copy. */
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24
25#include "sysdep.h"
26#include "asm-syntax.h"
27
c891b2df 28 .text
847b055c 29ENTRY(__bcopy)
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30 ltgr %r1,%r4 # zero bcopy ?
31 jz .L4
32 clgr %r2,%r3 # check against destructive overlap
33 jnl .L0
34 algr %r1,%r2
35 clgr %r1,%r3
3c204435 36 jh .L7
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37.L0: aghi %r4,-1 # length - 1
38 srlg %r1,%r4,8
3c204435 39 ltgr %r1,%r1 # < 256 bytes to move ?
c891b2df 40 jz .L2
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41 cghi %r1,255 # > 1MB to move ?
42 jh .L5
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43.L1: mvc 0(256,%r3),0(%r2) # move in 256 byte chunks
44 la %r2,256(%r2)
45 la %r3,256(%r3)
46 brctg %r1,.L1
47.L2: bras %r1,.L3 # setup base pointer for execute
48 mvc 0(1,%r3),0(%r2) # instruction for execute
49.L3: ex %r4,0(%r1) # execute mvc with length ((%r4)&255)+1
50.L4: br %r14
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51 # data copies > 1MB are faster with mvcle.
52.L5: aghi %r4,1 # length + 1
53 lgr %r5,%r4 # source length
54 lgr %r4,%r2 # source address
55 lgr %r2,%r3 # set destination
56 lgr %r3,%r5 # destination length = source length
57.L6: mvcle %r2,%r4,0 # thats it, MVCLE is your friend
58 jo .L6
59 br %r14
60.L7: # destructive overlay, can not use mvcle
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61 lgr %r1,%r2 # bcopy is called with source,dest
62 lgr %r2,%r3 # memmove with dest,source! Oh, well...
63 lgr %r3,%r1
64 jg HIDDEN_BUILTIN_JUMPTARGET(memmove)
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65
66END(__bcopy)
67
68#ifndef NO_WEAK_ALIAS
69weak_alias (__bcopy, bcopy)
70#endif
ffeac417 71