1/* Multiply a limb vector by a single limb, for PowerPC.
2   Copyright (C) 1993-2022 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_submul_1 (mp_ptr res_ptr, mp_srcptr s1_ptr,
22                           mp_size_t s1_size, mp_limb_t s2_limb)
23   Calculate res-s1*s2 and put result back in res; return carry.  */
24
25ENTRY (__mpn_submul_1)
26	mtctr	r5
27
28	lwz	r0,0(r4)
29	mullw	r7,r0,r6
30	mulhwu	r10,r0,r6
31	lwz     r9,0(r3)
32	subf 	r8,r7,r9
33	addc    r7,r7,r8		# invert cy (r7 is junk)
34	addi	r3,r3,-4		# adjust res_ptr
35	bdz	L(1)
36
37L(0):	lwzu	r0,4(r4)
38	stwu	r8,4(r3)
39	mullw	r8,r0,r6
40	adde	r7,r8,r10
41	mulhwu	r10,r0,r6
42	lwz     r9,4(r3)
43	addze   r10,r10
44	subf    r8,r7,r9
45	addc    r7,r7,r8		# invert cy (r7 is junk)
46	bdnz	L(0)
47
48L(1):	stw	r8,4(r3)
49	addze	r3,r10
50	blr
51END (__mpn_submul_1)
52