1/* Add two limb vectors of equal, non-zero length for PowerPC.
2   Copyright (C) 1997-2022 Free Software Foundation, Inc.
3   This file is part of the GNU C Library.
4
5   The GNU C Library is free software; you can redistribute it and/or
6   modify it under the terms of the GNU Lesser General Public
7   License as published by the Free Software Foundation; either
8   version 2.1 of the License, or (at your option) any later version.
9
10   The GNU C Library is distributed in the hope that it will be useful,
11   but WITHOUT ANY WARRANTY; without even the implied warranty of
12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13   Lesser General Public License for more details.
14
15   You should have received a copy of the GNU Lesser General Public
16   License along with the GNU C Library; if not, see
17   <https://www.gnu.org/licenses/>.  */
18
19#include <sysdep.h>
20
21/* mp_limb_t mpn_add_n (mp_ptr res_ptr, mp_srcptr s1_ptr, mp_srcptr s2_ptr,
22                        mp_size_t size)
23   Calculate s1+s2 and put result in res_ptr; return carry, 0 or 1.  */
24
25/* Note on optimisation: This code is optimal for the 601.  Almost every other
26   possible 2-unrolled inner loop will not be.  Also, watch out for the
27   alignment...  */
28
29EALIGN (__mpn_add_n, 3, 0)
30
31/* Set up for loop below.  */
32	mtcrf 0x01,r6
33	srwi. r7,r6,1
34	li    r10,0
35	mtctr r7
36	bt    31,L(2)
37
38/* Clear the carry.  */
39	addic r0,r0,0
40/* Adjust pointers for loop.  */
41	addi  r3,r3,-4
42	addi  r4,r4,-4
43	addi  r5,r5,-4
44	b     L(0)
45
46L(2):	lwz  r7,0(r5)
47	lwz  r6,0(r4)
48	addc r6,r6,r7
49	stw  r6,0(r3)
50        beq  L(1)
51
52/* The loop.  */
53
54/* Align start of loop to an odd word boundary to guarantee that the
55   last two words can be fetched in one access (for 601).  */
56L(0):	lwz  r9,4(r4)
57	lwz  r8,4(r5)
58	lwzu r6,8(r4)
59	lwzu r7,8(r5)
60	adde r8,r9,r8
61	stw  r8,4(r3)
62	adde r6,r6,r7
63	stwu r6,8(r3)
64	bdnz L(0)
65/* Return the carry.  */
66L(1):	addze r3,r10
67	blr
68END (__mpn_add_n)
69