1/* Optimized version of the standard strchr() function.
2   This file is part of the GNU C Library.
3   Copyright (C) 2000, 2001, 2003 Free Software Foundation, Inc.
4   Contributed by Dan Pop <Dan.Pop@cern.ch>.
5
6   The GNU C Library is free software; you can redistribute it and/or
7   modify it under the terms of the GNU Lesser General Public
8   License as published by the Free Software Foundation; either
9   version 2.1 of the License, or (at your option) any later version.
10
11   The GNU C Library is distributed in the hope that it will be useful,
12   but WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14   Lesser General Public License for more details.
15
16   You should have received a copy of the GNU Lesser General Public
17   License along with the GNU C Library; if not, see
18   <http://www.gnu.org/licenses/>.  */
19
20/* Return: the address of the first occurence of chr in str or NULL
21
22   Inputs:
23        in0:    str
24        in1:    chr
25
26   A modified version of memchr.S, the search ends when the character is
27   found or the terminating null character is encountered.
28
29   This implementation assumes little endian mode.  For big endian mode,
30   the instruction czx1.r should be replaced by czx1.l.  */
31
32#include <sysdep.h>
33#undef ret
34
35#define saved_lc	r18
36#define poschr		r19
37#define pos0		r20
38#define val1		r21
39#define val2		r22
40#define tmp		r24
41#define chrx8		r25
42#define loopcnt		r30
43
44#define str		in0
45#define chr		in1
46
47ENTRY(strchr)
48	.prologue
49	alloc r2 = ar.pfs, 2, 0, 0, 0
50	.save ar.lc, saved_lc
51        mov 	saved_lc = ar.lc 	/* save the loop counter */
52	.body
53	mov 	ret0 = str
54	and 	tmp = 7, str		/* tmp = str % 8 */
55	mux1	chrx8 = chr, @brcst
56	extr.u	chr = chr, 0, 8		/* retain only the last byte */
57	cmp.ne	p8, p0 = r0, r0		/* clear p8 */
58	;;
59	sub	loopcnt = 8, tmp	/* loopcnt = 8 - tmp */
60	cmp.eq	p6, p0 = tmp, r0
61(p6)	br.cond.sptk	.str_aligned;;
62	adds	loopcnt = -1, loopcnt;;
63	mov	ar.lc = loopcnt
64.l1:
65	ld1	val2 = [ret0], 1
66	;;
67	cmp.eq	p6, p0 = val2, chr
68	cmp.eq	p7, p0 = val2, r0
69(p6)	br.cond.spnt	.restore_and_exit
70(p7)	br.cond.spnt	.notfound
71	br.cloop.sptk	.l1
72.str_aligned:
73	ld8	val1 = [ret0], 8;;
74	nop.b	0
75	nop.b 	0
76.l2:
77	ld8.s	val2 = [ret0], 8	/* don't bomb out here */
78	czx1.r	pos0 = val1
79	xor	tmp = val1, chrx8	/* if val1 contains chr, tmp will */
80	;;				/* contain a zero in its position */
81	czx1.r	poschr = tmp
82	cmp.ne	p6, p0 = 8, pos0
83	;;
84	cmp.ne	p7, p0 = 8, poschr
85(p7)	br.cond.spnt .foundit
86(p6)	br.cond.spnt .notfound
87	chk.s	val2, .recovery
88.back:
89	mov	val1 = val2
90	br.cond.dptk .l2
91.foundit:
92(p6)	cmp.lt	p8, p0 = pos0, poschr	/* we found chr and null in the word */
93(p8)	br.cond.spnt .notfound		/* null was found before chr */
94	add	ret0 = ret0, poschr ;;
95	adds	ret0 = -15, ret0 ;;	/* should be -16, but we decrement */
96.restore_and_exit:			/* ret0 in the next instruction */
97	adds	ret0 = -1, ret0		/* ret0 was pointing 1 char too far */
98	mov 	ar.lc = saved_lc	/* restore the loop counter */
99	br.ret.sptk.many b0
100.notfound:
101	mov	ret0 = r0		/* return NULL if null was found */
102	mov 	ar.lc = saved_lc
103	br.ret.sptk.many b0
104.recovery:
105	adds	ret0 = -8, ret0;;
106	ld8	val2 = [ret0], 8	/* bomb out here */
107	br.cond.sptk	.back
108END(strchr)
109libc_hidden_def (strchr)
110#ifdef __UCLIBC_SUSV3_LEGACY__
111strong_alias (strchr, index)
112#endif
113