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# MIPS __mpn_submul_1 -- Multiply a limb vector with a single limb and
# subtract the product from a second limb vector.
# Copyright (C) 1992, 1994 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.
# INPUT PARAMETERS
# res_ptr $4
# s1_ptr $5
# size $6
# s2_limb $7
.text
.align 4
.globl __mpn_submul_1
.ent __mpn_submul_1
__mpn_submul_1:
.set noreorder
.set nomacro
# warm up phase 0
lw $8,0($5)
# warm up phase 1
addiu $5,$5,4
multu $8,$7
addiu $6,$6,-1
beq $6,$0,$LC0
move $2,$0 # zero cy2
addiu $6,$6,-1
beq $6,$0,$LC1
lw $8,0($5) # load new s1 limb as early as possible
Loop: lw $10,0($4)
mflo $3
mfhi $9
addiu $5,$5,4
addu $3,$3,$2 # add old carry limb to low product limb
multu $8,$7
lw $8,0($5) # load new s1 limb as early as possible
addiu $6,$6,-1 # decrement loop counter
sltu $2,$3,$2 # carry from previous addition -> $2
subu $3,$10,$3
sgtu $10,$3,$10
addu $2,$2,$10
sw $3,0($4)
addiu $4,$4,4
bne $6,$0,Loop # should be "bnel"
addu $2,$9,$2 # add high product limb and carry from addition
# cool down phase 1
$LC1: lw $10,0($4)
mflo $3
mfhi $9
addu $3,$3,$2
sltu $2,$3,$2
multu $8,$7
subu $3,$10,$3
sgtu $10,$3,$10
addu $2,$2,$10
sw $3,0($4)
addiu $4,$4,4
addu $2,$9,$2 # add high product limb and carry from addition
# cool down phase 0
$LC0: lw $10,0($4)
mflo $3
mfhi $9
addu $3,$3,$2
sltu $2,$3,$2
subu $3,$10,$3
sgtu $10,$3,$10
addu $2,$2,$10
sw $3,0($4)
j $31
addu $2,$9,$2 # add high product limb and carry from addition
.end __mpn_submul_1
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