1 /* __mpn_sub_n -- Add two limb vectors of the same length > 0 and store
2 sum in a third limb vector. 64 bit S/390 version.
3 Copyright (C) 2001-2024 Free Software Foundation, Inc.
4 This file is part of the GNU MP Library.
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 License as
8 published by the Free Software Foundation; either version 2.1 of the
9 License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; see the file COPYING.LIB. If not,
18 see <https://www.gnu.org/licenses/>. */
27 #include "asm-syntax.h"
30 stg %r6,48(%r15) # save register 6
33 lghi %r0,1 # cannot use ahi to add carry, use slr
34 .L0: lg %r6,0(%r1,%r3) # .L0 -> no carry from last sub
40 slgr %r2,%r2 # no last carry to return
42 .L2: lg %r6,0(%r1,%r3) # .L2 -> carry from last sub
45 slgr %r6,%r0 # no carry yet, add carry from last sub
48 brc 11,.L1 # new carry ?
50 lgr %r2,%r0 # return last carry
52 .L4: slgr %r6,%r0 # already a carry, add carry from last sub
56 lgr %r2,%r0 # return last carry
57 .Lexit: lg %r6,48(%r15) # restore register 6