xref: /netbsd-src/external/lgpl3/gmp/dist/mpn/thumb/add_n.asm (revision 9fb66d812c00ebfb445c0b47dea128f32aa6fe96)
1dnl  ARM/Thumb mpn_add_n.
2
3dnl  Copyright 1997, 2000, 2012 Free Software Foundation, Inc.
4
5dnl  This file is part of the GNU MP Library.
6dnl
7dnl  The GNU MP Library is free software; you can redistribute it and/or modify
8dnl  it under the terms of either:
9dnl
10dnl    * the GNU Lesser General Public License as published by the Free
11dnl      Software Foundation; either version 3 of the License, or (at your
12dnl      option) any later version.
13dnl
14dnl  or
15dnl
16dnl    * the GNU General Public License as published by the Free Software
17dnl      Foundation; either version 2 of the License, or (at your option) any
18dnl      later version.
19dnl
20dnl  or both in parallel, as here.
21dnl
22dnl  The GNU MP Library is distributed in the hope that it will be useful, but
23dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
24dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
25dnl  for more details.
26dnl
27dnl  You should have received copies of the GNU General Public License and the
28dnl  GNU Lesser General Public License along with the GNU MP Library.  If not,
29dnl  see https://www.gnu.org/licenses/.
30
31include(`../config.m4')
32
33C INPUT PARAMETERS
34define(`rp',	r0)
35define(`up',	r1)
36define(`vp',	r2)
37define(`n',	r3)
38
39ASM_START()
40	.thumb
41PROLOGUE(mpn_add_nc)
42	push	{r4, r5, r6}
43	ldr	r6, [sp, #12]		C init carry save register
44	sub	r6, #1
45	b	L(top)
46EPILOGUE()
47PROLOGUE(mpn_add_n)
48	push	{r4, r5, r6}
49	neg	r6, n			C init carry save register
50
51L(top):	ldmia	up!, {r4}		C load next limb from S1
52	cmp	n, r6			C tricky carry restore
53	ldmia	vp!, {r5}		C load next limb from S2
54	adc	r4, r5
55	stmia	rp!, {r4}		C store result limb to RES
56	sbc	r6, r6			C save negated carry
57	sub	n, #1
58	bne	L(top)
59
60	add	r0, r6, #1
61	pop	{r4, r5, r6}
62	bx	lr
63EPILOGUE()
64