mpir/mpn/i960/sub_n.s

44 lines
1.5 KiB
ArmAsm

# I960 __gmpn_sub_n -- Subtract two limb vectors of the same length > 0 and
# store difference in a third limb vector.
# Copyright 1995, 2000 Free Software Foundation, Inc.
# 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 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 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 Lesser General Public
# License for more details.
# You should have received a copy of the GNU Lesser General Public License
# along with the GNU MP Library; see the file COPYING.LIB. If not, write to
# the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA 02110-1301, USA.
.text
.align 4
.globl ___gmpn_sub_n
___gmpn_sub_n:
mov 1,g6 # set carry-save register
cmpo 1,0 # clear cy
Loop: subo 1,g3,g3 # update loop counter
ld (g1),g5 # load from s1_ptr
addo 4,g1,g1 # s1_ptr++
ld (g2),g4 # load from s2_ptr
addo 4,g2,g2 # s2_ptr++
cmpo g6,1 # restore cy from g6, relies on cy being 0
subc g4,g5,g4 # main subtract
subc 0,0,g6 # save cy in g6
st g4,(g0) # store result to res_ptr
addo 4,g0,g0 # res_ptr++
cmpobne 0,g3,Loop # when branch is taken, cy will be 0
mov g6,g0
ret