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/* __mpn_sub_n -- Add two limb vectors of the same length > 0 and store
sum in a third limb vector.
Copyright (C) 2000, 2001 Free Software Foundation, Inc.
Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
This file is part of the GNU MP Library.
The GNU MP 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 MP 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 MP 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. */
/*
INPUT PARAMETERS
res_ptr %r2
s1_ptr %r3
s2_ptr %r4
size %r5
*/
#include "sysdep.h"
#include "asm-syntax.h"
ENTRY(__mpn_sub_n)
st %r6,24(%r15) # save register 6
sr %r1,%r1
lhi %r0,1 # cannot use ahi to add carry, use slr
.L0: l %r6,0(%r1,%r3) # .L0 -> no carry from last sub
sl %r6,0(%r1,%r4)
st %r6,0(%r1,%r2)
la %r1,4(0,%r1)
brc 4,.L3
.L1: brct %r5,.L0
slr %r2,%r2 # no last carry to return
j .Lexit
.L2: l %r6,0(%r1,%r3) # .L2 -> carry from last sub
sl %r6,0(%r1,%r4)
brc 4,.L4
slr %r6,%r0 # no carry yet, add carry from last sub
st %r6,0(%r1,%r2)
la %r1,4(0,%r1)
brc 11,.L1 # new carry ?
.L3: brct %r5,.L2
lr %r2,%r0 # return last carry
j .Lexit
.L4: slr %r6,%r0 # already a carry, add carry from last sub
st %r6,0(%r1,%r2)
la %r1,4(0,%r1)
brct %r5,.L2
lr %r2,%r0 # return last carry
.Lexit: l %r6,24(%r15) # restore register 6
br %r14
END(__mpn_sub_n)
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