mpir/mpn/a29k/add_n.s

121 lines
3.0 KiB
ArmAsm

; 29000 mpn_add_n -- Add two limb vectors of the same length > 0 and store
; sum in a third limb vector.
; Copyright 1992, 1994, 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.
; INPUT PARAMETERS
; res_ptr lr2
; s1_ptr lr3
; s2_ptr lr4
; size lr5
; We use the loadm/storem instructions and operate on chunks of 8
; limbs/per iteration, until less than 8 limbs remain.
; The 29k has no addition or subtraction instructions that doesn't
; affect carry, so we need to save and restore that as soon as we
; adjust the pointers. gr116 is used for this purpose. Note that
; gr116==0 means that carry should be set.
.sect .lit,lit
.text
.align 4
.global ___gmpn_add_n
.word 0x60000
___gmpn_add_n:
srl gr117,lr5,3
sub gr118,gr117,1
jmpt gr118,Ltail
constn gr116,-1 ; init cy reg
sub gr117,gr117,2 ; count for jmpfdec
; Main loop working 8 limbs/iteration.
Loop: mtsrim cr,(8-1)
loadm 0,0,gr96,lr3
add lr3,lr3,32
mtsrim cr,(8-1)
loadm 0,0,gr104,lr4
add lr4,lr4,32
subr gr116,gr116,0 ; restore carry
addc gr96,gr96,gr104
addc gr97,gr97,gr105
addc gr98,gr98,gr106
addc gr99,gr99,gr107
addc gr100,gr100,gr108
addc gr101,gr101,gr109
addc gr102,gr102,gr110
addc gr103,gr103,gr111
subc gr116,gr116,gr116 ; gr116 = not(cy)
mtsrim cr,(8-1)
storem 0,0,gr96,lr2
jmpfdec gr117,Loop
add lr2,lr2,32
; Code for the last up-to-7 limbs.
; This code might look very strange, but it's hard to write it
; differently without major slowdown.
and lr5,lr5,(8-1)
Ltail: sub gr118,lr5,1 ; count for CR
jmpt gr118,Lend
sub gr117,lr5,2 ; count for jmpfdec
mtsr cr,gr118
loadm 0,0,gr96,lr3
mtsr cr,gr118
loadm 0,0,gr104,lr4
subr gr116,gr116,0 ; restore carry
jmpfdec gr117,L1
addc gr96,gr96,gr104
jmp Lstore
mtsr cr,gr118
L1: jmpfdec gr117,L2
addc gr97,gr97,gr105
jmp Lstore
mtsr cr,gr118
L2: jmpfdec gr117,L3
addc gr98,gr98,gr106
jmp Lstore
mtsr cr,gr118
L3: jmpfdec gr117,L4
addc gr99,gr99,gr107
jmp Lstore
mtsr cr,gr118
L4: jmpfdec gr117,L5
addc gr100,gr100,gr108
jmp Lstore
mtsr cr,gr118
L5: jmpfdec gr117,L6
addc gr101,gr101,gr109
jmp Lstore
mtsr cr,gr118
L6: addc gr102,gr102,gr110
Lstore: storem 0,0,gr96,lr2
subc gr116,gr116,gr116 ; gr116 = not(cy)
Lend: jmpi lr0
add gr96,gr116,1