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/* MIPS3 submul_1 -- Multiply a limb vector with a single limb and
* subtract the product from a second limb vector.
*
* Copyright (C) 1992, 1994, 1995, 1998, 2000
* 2001 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* GnuPG 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*/
/*******************
* mpi_limb_t
* mpihelp_submul_1( mpi_ptr_t res_ptr, (r4)
* mpi_ptr_t s1_ptr, (r5)
* mpi_size_t s1_size, (r6)
* mpi_limb_t s2_limb) (r7)
*/
.text
.align 4
.globl mpihelp_submul_1
.ent mpihelp_submul_1
mpihelp_submul_1:
.set noreorder
.set nomacro
/* # warm up phase 0 */
ld $8,0($5)
/* # warm up phase 1 */
daddiu $5,$5,8
dmultu $8,$7
daddiu $6,$6,-1
beq $6,$0,$LC0
move $2,$0 # zero cy2
daddiu $6,$6,-1
beq $6,$0,$LC1
ld $8,0($5) # load new s1 limb as early as possible
Loop: ld $10,0($4)
mflo $3
mfhi $9
daddiu $5,$5,8
daddu $3,$3,$2 # add old carry limb to low product limb
dmultu $8,$7
ld $8,0($5) # load new s1 limb as early as possible
daddiu $6,$6,-1 # decrement loop counter
sltu $2,$3,$2 # carry from previous addition -> $2
dsubu $3,$10,$3
sgtu $10,$3,$10
daddu $2,$2,$10
sd $3,0($4)
daddiu $4,$4,8
bne $6,$0,Loop
daddu $2,$9,$2 # add high product limb and carry from addition
/* # cool down phase 1 */
$LC1: ld $10,0($4)
mflo $3
mfhi $9
daddu $3,$3,$2
sltu $2,$3,$2
dmultu $8,$7
dsubu $3,$10,$3
sgtu $10,$3,$10
daddu $2,$2,$10
sd $3,0($4)
daddiu $4,$4,8
daddu $2,$9,$2 # add high product limb and carry from addition
/* # cool down phase 0 */
$LC0: ld $10,0($4)
mflo $3
mfhi $9
daddu $3,$3,$2
sltu $2,$3,$2
dsubu $3,$10,$3
sgtu $10,$3,$10
daddu $2,$2,$10
sd $3,0($4)
j $31
daddu $2,$9,$2 # add high product limb and carry from addition
.end mpihelp_submul_1
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