mirror of
git://sourceware.org/git/glibc.git
synced 2024-12-21 04:31:04 +08:00
109 lines
2.5 KiB
ArmAsm
109 lines
2.5 KiB
ArmAsm
|
# Alpha 21064 __mpn_lshift --
|
||
|
|
|
||
|
|
# Copyright (C) 1994, 1995 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 r16
|
||
|
|
# s1_ptr r17
|
||
|
|
# size r18
|
||
|
|
# cnt r19
|
||
|
|
|
||
|
|
# This code runs at 4.8 cycles/limb on the 21064. With infinite unrolling,
|
||
|
|
# it would take 4 cycles/limb. It should be possible to get down to 3
|
||
|
|
# cycles/limb since both ldq and stq can be paired with the other used
|
||
|
|
# instructions. But there are many restrictions in the 21064 pipeline that
|
||
|
|
# makes it hard, if not impossible, to get down to 3 cycles/limb:
|
||
|
|
|
||
|
|
# 1. ldq has a 3 cycle delay, srl and sll have a 2 cycle delay.
|
||
|
|
# 2. Only aligned instruction pairs can be paired.
|
||
|
|
# 3. The store buffer or silo might not be able to deal with the bandwidth.
|
||
|
|
|
||
|
|
.set noreorder
|
||
|
|
.set noat
|
||
|
|
.text
|
||
|
|
.align 3
|
||
|
|
.globl __mpn_lshift
|
||
|
|
.ent __mpn_lshift
|
||
|
|
__mpn_lshift:
|
||
|
|
.frame $30,0,$26,0
|
||
|
|
|
||
|
|
s8addq $18,$17,$17 # make r17 point at end of s1
|
||
|
|
ldq $4,-8($17) # load first limb
|
||
|
|
subq $17,8,$17
|
||
|
|
subq $31,$19,$7
|
||
|
|
s8addq $18,$16,$16 # make r16 point at end of RES
|
||
|
|
subq $18,1,$18
|
||
|
|
and $18,4-1,$20 # number of limbs in first loop
|
||
|
|
srl $4,$7,$0 # compute function result
|
||
|
|
|
||
|
|
beq $20,L0
|
||
|
|
subq $18,$20,$18
|
||
|
|
|
||
|
|
.align 3
|
||
|
|
Loop0:
|
||
|
|
ldq $3,-8($17)
|
||
|
|
subq $16,8,$16
|
||
|
|
subq $17,8,$17
|
||
|
|
subq $20,1,$20
|
||
|
|
sll $4,$19,$5
|
||
|
|
srl $3,$7,$6
|
||
|
|
bis $3,$3,$4
|
||
|
|
bis $5,$6,$8
|
||
|
|
stq $8,0($16)
|
||
|
|
bne $20,Loop0
|
||
|
|
|
||
|
|
L0: beq $18,Lend
|
||
|
|
|
||
|
|
.align 3
|
||
|
|
Loop: ldq $3,-8($17)
|
||
|
|
subq $16,32,$16
|
||
|
|
subq $18,4,$18
|
||
|
|
sll $4,$19,$5
|
||
|
|
srl $3,$7,$6
|
||
|
|
|
||
|
|
ldq $4,-16($17)
|
||
|
|
sll $3,$19,$1
|
||
|
|
bis $5,$6,$8
|
||
|
|
stq $8,24($16)
|
||
|
|
srl $4,$7,$2
|
||
|
|
|
||
|
|
ldq $3,-24($17)
|
||
|
|
sll $4,$19,$5
|
||
|
|
bis $1,$2,$8
|
||
|
|
stq $8,16($16)
|
||
|
|
srl $3,$7,$6
|
||
|
|
|
||
|
|
ldq $4,-32($17)
|
||
|
|
sll $3,$19,$1
|
||
|
|
bis $5,$6,$8
|
||
|
|
stq $8,8($16)
|
||
|
|
srl $4,$7,$2
|
||
|
|
|
||
|
|
subq $17,32,$17
|
||
|
|
bis $1,$2,$8
|
||
|
|
stq $8,0($16)
|
||
|
|
|
||
|
|
bgt $18,Loop
|
||
|
|
|
||
|
|
Lend: sll $4,$19,$8
|
||
|
|
stq $8,-8($16)
|
||
|
|
ret $31,($26),1
|
||
|
|
.end __mpn_lshift
|