1/* Shift a limb right, low level routine.
2   Copyright (C) 1995, 1997, 1999, 2000 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, write to the Free
17   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18   02111-1307 USA.  */
19
20#include <sysdep.h>
21#include <bp-sym.h>
22#include <bp-asm.h>
23
24/* INPUT PARAMETERS
25   res_ptr	r3
26   s1_ptr	r4
27   size		r5
28   cnt		r6  */
29
30ENTRY (BP_SYM (__mpn_rshift))
31#if __BOUNDED_POINTERS__
32	slwi r10,r5,2		/* convert limbs to bytes */
33	CHECK_BOUNDS_BOTH_WIDE (r3, r8, r9, r10)
34	CHECK_BOUNDS_BOTH_WIDE (r4, r8, r9, r10)
35#endif
36	mtctr	r5		# copy size into CTR
37	addi	r7,r3,-4	# move adjusted res_ptr to free return reg
38	subfic	r8,r6,32
39	lwz	r11,0(r4)	# load first s1 limb
40	slw	r3,r11,r8	# compute function return value
41	bdz	L(1)
42
43L(0):	lwzu	r10,4(r4)
44	srw	r9,r11,r6
45	slw	r12,r10,r8
46	or	r9,r9,r12
47	stwu	r9,4(r7)
48	bdz	L(2)
49	lwzu	r11,4(r4)
50	srw	r9,r10,r6
51	slw	r12,r11,r8
52	or	r9,r9,r12
53	stwu	r9,4(r7)
54	bdnz	L(0)
55
56L(1):	srw	r0,r11,r6
57	stw	r0,4(r7)
58	blr
59
60L(2):	srw	r0,r10,r6
61	stw	r0,4(r7)
62	blr
63END (BP_SYM (__mpn_rshift))
64