2010-03-03 19:20:03 +00:00
|
|
|
/* bigint_add_u.S */
|
|
|
|
/*
|
|
|
|
This file is part of the AVR-Crypto-Lib.
|
2015-02-06 02:43:31 +00:00
|
|
|
Copyright (C) 2006-2015 Daniel Otte (bg@nerilex.org)
|
2010-03-03 19:20:03 +00:00
|
|
|
|
|
|
|
This program 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 3 of the License, or
|
|
|
|
(at your option) any later version.
|
|
|
|
|
|
|
|
This program 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, see <http://www.gnu.org/licenses/>.
|
|
|
|
*/
|
|
|
|
|
|
|
|
/**
|
|
|
|
* \file bigint_add_u.S
|
2015-02-06 02:43:31 +00:00
|
|
|
* \email bg@nerilex.org
|
2010-03-03 19:20:03 +00:00
|
|
|
* \author Daniel Otte
|
|
|
|
* \date 2010-03-01
|
|
|
|
* \license GPLv3 or later
|
|
|
|
*
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
param dest: r24:r25
|
|
|
|
param a: r22:r23
|
|
|
|
param b: r20:r21
|
|
|
|
*/
|
|
|
|
LEN_A_0 = 22
|
|
|
|
LEN_A_1 = 23
|
|
|
|
LEN_B_0 = 20
|
|
|
|
LEN_B_1 = 21
|
|
|
|
|
|
|
|
|
|
|
|
.global bigint_add_u
|
|
|
|
bigint_add_u:
|
|
|
|
push_range 28, 29
|
|
|
|
push_range 24, 25
|
|
|
|
movw r26, r24 ; X is our destination pointer
|
|
|
|
movw r30, r22 ; Z = a
|
|
|
|
movw r28, r20 ; Y = b
|
|
|
|
ldd LEN_A_0, Z+0
|
|
|
|
ldd LEN_A_1, Z+1
|
|
|
|
ldd LEN_B_0, Y+0
|
|
|
|
ldd LEN_B_1, Y+1
|
|
|
|
cp LEN_A_0, LEN_B_0
|
|
|
|
cpc LEN_A_1, LEN_B_1
|
|
|
|
brsh 3f
|
|
|
|
movw r18, LEN_A_0 ; swap length values
|
|
|
|
movw LEN_A_0, LEN_B_0
|
|
|
|
movw LEN_B_0, r18
|
|
|
|
movw r18, r30 ; swap pointers
|
|
|
|
movw r30, r28
|
|
|
|
movw r28, r18
|
|
|
|
3: ; now a is the longer integer
|
|
|
|
movw r24, LEN_A_0
|
|
|
|
adiw r24, 0
|
|
|
|
brne 4f
|
|
|
|
st X+, r1 ; store length
|
|
|
|
st X+, r1
|
|
|
|
st X+, r1 ; store 0 in info field
|
|
|
|
rjmp 9f
|
|
|
|
4:
|
|
|
|
adiw r24, 1
|
|
|
|
st X+, r24 ; store length
|
|
|
|
st X+, r25
|
|
|
|
st X+, r1 ; store 0 in info field
|
|
|
|
ld r18, X+
|
|
|
|
ld r19, X+
|
|
|
|
movw r26, r18
|
|
|
|
adiw r30, 3 ; adjust pointers to point at wordv
|
|
|
|
ld r18, Z+
|
|
|
|
ld r19, Z+
|
|
|
|
movw r30, r18
|
|
|
|
adiw r28, 3
|
|
|
|
ld r18, Y+
|
|
|
|
ld r19, Y+
|
|
|
|
movw r28, r18
|
|
|
|
|
|
|
|
sub LEN_A_0, LEN_B_0
|
|
|
|
sbc LEN_A_1, LEN_B_1
|
|
|
|
movw r24, LEN_B_0
|
|
|
|
clr r0
|
|
|
|
adiw r24, 0
|
|
|
|
breq 6f
|
|
|
|
clc
|
|
|
|
5:
|
|
|
|
ld r0, Z+
|
|
|
|
ld r1, Y+
|
|
|
|
adc r0, r1
|
|
|
|
st X+, r0
|
|
|
|
dec r24
|
|
|
|
brne 5b
|
|
|
|
rol r0 ; store carry bit
|
|
|
|
tst r25
|
|
|
|
breq 6f
|
|
|
|
dec r25
|
|
|
|
dec r24
|
|
|
|
ror r0 ; write carry back
|
|
|
|
rjmp 5b
|
|
|
|
6: /* the main part is done */
|
|
|
|
movw r24, LEN_A_0
|
|
|
|
clr r1
|
|
|
|
adiw r24, 0
|
|
|
|
breq 8f
|
|
|
|
62:
|
|
|
|
ror r0 ; write carry back
|
|
|
|
7:
|
|
|
|
ld r0, Z+
|
|
|
|
adc r0, r1
|
|
|
|
st X+, r0
|
|
|
|
dec r24
|
|
|
|
brne 7b
|
|
|
|
rol r0 ; store carry bit
|
|
|
|
tst r25
|
|
|
|
breq 8f
|
|
|
|
dec r25
|
|
|
|
dec r24
|
|
|
|
rjmp 62b
|
|
|
|
8:
|
|
|
|
ror r0
|
|
|
|
clr r0
|
|
|
|
rol r0
|
|
|
|
st X+, r0
|
|
|
|
9:
|
|
|
|
pop_range 24, 25
|
|
|
|
pop_range 28, 29
|
2011-07-05 19:34:03 +00:00
|
|
|
rjmp bigint_adjust
|
2010-03-03 19:20:03 +00:00
|
|
|
|
|
|
|
|