1/* Shift a limb left, low level routine.
2   Copyright (C) 1996, 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/* mp_limb_t mpn_lshift (mp_ptr wp, mp_srcptr up, mp_size_t usize,
25  			 unsigned int cnt)  */
26
27EALIGN (BP_SYM (__mpn_lshift), 3, 0)
28
29#if __BOUNDED_POINTERS__
30	slwi r10,r5,2		/* convert limbs to bytes */
31	CHECK_BOUNDS_BOTH_WIDE (r3, r8, r9, r10)
32	CHECK_BOUNDS_BOTH_WIDE (r4, r8, r9, r10)
33#endif
34	mtctr	r5		# copy size into CTR
35	cmplwi	cr0,r5,16	# is size < 16
36	slwi	r0,r5,2
37	add	r7,r3,r0	# make r7 point at end of res
38	add	r4,r4,r0	# make r4 point at end of s1
39	lwzu	r11,-4(r4)	# load first s1 limb
40	subfic	r8,r6,32
41	srw	r3,r11,r8	# compute function return value
42	bge	cr0,L(big)	# branch if size >= 16
43
44	bdz	L(end1)
45
46L(0):	lwzu	r10,-4(r4)
47	slw	r9,r11,r6
48	srw	r12,r10,r8
49	or	r9,r9,r12
50	stwu	r9,-4(r7)
51	bdz	L(end2)
52	lwzu	r11,-4(r4)
53	slw	r9,r10,r6
54	srw	r12,r11,r8
55	or	r9,r9,r12
56	stwu	r9,-4(r7)
57	bdnz	L(0)
58
59L(end1):slw	r0,r11,r6
60	stw	r0,-4(r7)
61	blr
62
63
64/* Guaranteed not to succeed.  */
65L(boom): tweq    r0,r0
66
67/* We imitate a case statement, by using (yuk!) fixed-length code chunks,
68   of size 4*12 bytes.  We have to do this (or something) to make this PIC.  */
69L(big):	mflr    r9
70	bltl-   cr0,L(boom)	# Never taken, only used to set LR.
71	slwi    r10,r6,4
72	mflr    r12
73	add     r10,r12,r10
74	slwi	r8,r6,5
75	add     r10,r8,r10
76	mtctr   r10
77	addi	r5,r5,-1
78	mtlr    r9
79	bctr
80
81L(end2):slw	r0,r10,r6
82	stw	r0,-4(r7)
83	blr
84
85#define DO_LSHIFT(n) \
86	mtctr	r5;							\
87L(n):	lwzu	r10,-4(r4);						\
88	slwi	r9,r11,n;						\
89	inslwi	r9,r10,n,32-n;					\
90	stwu	r9,-4(r7);						\
91	bdz-	L(end2);						\
92	lwzu	r11,-4(r4);						\
93	slwi	r9,r10,n;						\
94	inslwi	r9,r11,n,32-n;					\
95	stwu	r9,-4(r7);						\
96	bdnz	L(n);							\
97	b	L(end1)
98
99	DO_LSHIFT(1)
100	DO_LSHIFT(2)
101	DO_LSHIFT(3)
102	DO_LSHIFT(4)
103	DO_LSHIFT(5)
104	DO_LSHIFT(6)
105	DO_LSHIFT(7)
106	DO_LSHIFT(8)
107	DO_LSHIFT(9)
108	DO_LSHIFT(10)
109	DO_LSHIFT(11)
110	DO_LSHIFT(12)
111	DO_LSHIFT(13)
112	DO_LSHIFT(14)
113	DO_LSHIFT(15)
114	DO_LSHIFT(16)
115	DO_LSHIFT(17)
116	DO_LSHIFT(18)
117	DO_LSHIFT(19)
118	DO_LSHIFT(20)
119	DO_LSHIFT(21)
120	DO_LSHIFT(22)
121	DO_LSHIFT(23)
122	DO_LSHIFT(24)
123	DO_LSHIFT(25)
124	DO_LSHIFT(26)
125	DO_LSHIFT(27)
126	DO_LSHIFT(28)
127	DO_LSHIFT(29)
128	DO_LSHIFT(30)
129	DO_LSHIFT(31)
130
131END (BP_SYM (__mpn_lshift))
132