1/* Copyright (C) 2000-2021 Free Software Foundation, Inc.
2   This file is part of the GNU C Library.
3
4   The GNU C Library is free software; you can redistribute it and/or
5   modify it under the terms of the GNU Lesser General Public
6   License as published by the Free Software Foundation; either
7   version 2.1 of the License, or (at your option) any later version.
8
9   The GNU C Library is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12   Lesser General Public License for more details.
13
14   You should have received a copy of the GNU Lesser General Public
15   License along with the GNU C Library.  If not, see
16   <https://www.gnu.org/licenses/>.  */
17
18/* Return pointer to first occurrence of CH in STR.  */
19
20#include <sysdep.h>
21
22	.arch ev6
23	.set noreorder
24	.set noat
25
26ENTRY(__rawmemchr)
27#ifdef PROF
28	ldgp	gp, 0(pv)
29	lda	AT, _mcount
30	jsr	AT, (AT), _mcount
31	.prologue 1
32#else
33	.prologue 0
34#endif
35
36	ldq_u   t0, 0(a0)	# L : load first quadword Latency=3
37	and	a1, 0xff, t3	# E : 00000000000000ch
38	insbl	a1, 1, t5	# U : 000000000000ch00
39	insbl	a1, 7, a2	# U : ch00000000000000
40
41	insbl	t3, 6, a3	# U : 00ch000000000000
42	or	t5, t3, a1	# E : 000000000000chch
43	andnot  a0, 7, v0	# E : align our loop pointer
44	lda	t4, -1		# E : build garbage mask
45
46	mskqh	t4, a0, t4	# U : only want relevant part of first quad
47	or	a2, a3, a2	# E : chch000000000000
48	inswl	a1, 2, t5	# E : 00000000chch0000
49	inswl	a1, 4, a3	# E : 0000chch00000000
50
51	or	a1, a2, a1	# E : chch00000000chch
52	or	a3, t5, t5	# E : 0000chchchch0000
53	cmpbge	zero, t4, t4	# E : bits set iff byte is garbage
54	nop			# E :
55
56	/* This quad is _very_ serialized.  Lots of stalling happens */
57	or	t5, a1, a1	# E : chchchchchchchch
58	xor	t0, a1, t1	# E : make bytes == c zero
59	cmpbge  zero, t1, t0	# E : bits set iff byte == c
60	andnot	t0, t4, t0	# E : clear garbage bits
61
62	cttz	t0, a2		# U0 : speculative (in case we get a match)
63	nop			# E :
64	nop			# E :
65	bne	t0, $found	# U :
66
67	/*
68	 * Yuk.  This loop is going to stall like crazy waiting for the
69	 * data to be loaded.  Not much can be done about it unless it's
70	 * unrolled multiple times, which is generally unsafe.
71	 */
72$loop:
73	ldq	t0, 8(v0)	# L : Latency=3
74	addq	v0, 8, v0	# E :
75	xor	t0, a1, t1	# E :
76	cmpbge	zero, t1, t0	# E : bits set iff byte == c
77
78	cttz	t0, a2		# U0 : speculative (in case we get a match)
79	nop			# E :
80	nop			# E :
81	beq	t0, $loop	# U :
82
83$found:
84	negq    t0, t1		# E : clear all but least set bit
85	and     t0, t1, t0	# E :
86	addq	v0, a2, v0	# E : Add in the bit number from above
87	ret			# L0 :
88
89	END(__rawmemchr)
90
91libc_hidden_def (__rawmemchr)
92weak_alias (__rawmemchr, rawmemchr)
93