mirror of git://git.gnupg.org/gnupg.git
91 lines
2.8 KiB
ArmAsm
91 lines
2.8 KiB
ArmAsm
/* Alpha 21064 mpih-mul1.S -- Multiply a limb vector with a limb and store
|
|
* the result in a second limb vector.
|
|
*
|
|
* Copyright (C) 1992, 1994, 1995, 1998,
|
|
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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
|
|
*/
|
|
|
|
|
|
/*******************
|
|
* mpi_limb_t
|
|
* mpihelp_mul_1( mpi_ptr_t res_ptr, (r16)
|
|
* mpi_ptr_t s1_ptr, (r17)
|
|
* mpi_size_t s1_size, (r18)
|
|
* mpi_limb_t s2_limb) (r19)
|
|
*
|
|
* This code runs at 42 cycles/limb on the EV4 and 18 cycles/limb on the EV5.
|
|
*
|
|
* To improve performance for long multiplications, we would use
|
|
* 'fetch' for S1 and 'fetch_m' for RES. It's not obvious how to use
|
|
* these instructions without slowing down the general code: 1. We can
|
|
* only have two prefetches in operation at any time in the Alpha
|
|
* architecture. 2. There will seldom be any special alignment
|
|
* between RES_PTR and S1_PTR. Maybe we can simply divide the current
|
|
* loop into an inner and outer loop, having the inner loop handle
|
|
* exactly one prefetch block?
|
|
*/
|
|
|
|
.set noreorder
|
|
.set noat
|
|
.text
|
|
.align 3
|
|
.globl mpihelp_mul_1
|
|
.ent mpihelp_mul_1 2
|
|
mpihelp_mul_1:
|
|
.frame $30,0,$26
|
|
|
|
ldq $2,0($17) # $2 = s1_limb
|
|
subq $18,1,$18 # size--
|
|
mulq $2,$19,$3 # $3 = prod_low
|
|
bic $31,$31,$4 # clear cy_limb
|
|
umulh $2,$19,$0 # $0 = prod_high
|
|
beq $18,Lend1 # jump if size was == 1
|
|
ldq $2,8($17) # $2 = s1_limb
|
|
subq $18,1,$18 # size--
|
|
stq $3,0($16)
|
|
beq $18,Lend2 # jump if size was == 2
|
|
|
|
.align 3
|
|
Loop: mulq $2,$19,$3 # $3 = prod_low
|
|
addq $4,$0,$0 # cy_limb = cy_limb + 'cy'
|
|
subq $18,1,$18 # size--
|
|
umulh $2,$19,$4 # $4 = cy_limb
|
|
ldq $2,16($17) # $2 = s1_limb
|
|
addq $17,8,$17 # s1_ptr++
|
|
addq $3,$0,$3 # $3 = cy_limb + prod_low
|
|
stq $3,8($16)
|
|
cmpult $3,$0,$0 # $0 = carry from (cy_limb + prod_low)
|
|
addq $16,8,$16 # res_ptr++
|
|
bne $18,Loop
|
|
|
|
Lend2: mulq $2,$19,$3 # $3 = prod_low
|
|
addq $4,$0,$0 # cy_limb = cy_limb + 'cy'
|
|
umulh $2,$19,$4 # $4 = cy_limb
|
|
addq $3,$0,$3 # $3 = cy_limb + prod_low
|
|
cmpult $3,$0,$0 # $0 = carry from (cy_limb + prod_low)
|
|
stq $3,8($16)
|
|
addq $4,$0,$0 # cy_limb = prod_high + cy
|
|
ret $31,($26),1
|
|
Lend1: stq $3,0($16)
|
|
ret $31,($26),1
|
|
|
|
.end mpihelp_mul_1
|
|
|
|
|