xref: /freebsd/sys/libkern/arm64/crc32c_armv8.S (revision 0ec3e991112d85a790ca3bbb4175652f37f4bd15)
1d7f27102SMichael Tuexen/*-
2d7f27102SMichael Tuexen * Copyright (c) 2017 Michael Tuexen
3d7f27102SMichael Tuexen * All rights reserved.
4d7f27102SMichael Tuexen *
5d7f27102SMichael Tuexen * Redistribution and use in source and binary forms, with or without
6d7f27102SMichael Tuexen * modification, are permitted provided that the following conditions
7d7f27102SMichael Tuexen * are met:
8d7f27102SMichael Tuexen * 1. Redistributions of source code must retain the above copyright
9d7f27102SMichael Tuexen *    notice, this list of conditions and the following disclaimer.
10d7f27102SMichael Tuexen * 2. Redistributions in binary form must reproduce the above copyright
11d7f27102SMichael Tuexen *    notice, this list of conditions and the following disclaimer in the
12d7f27102SMichael Tuexen *    documentation and/or other materials provided with the distribution.
13d7f27102SMichael Tuexen *
14d7f27102SMichael Tuexen * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15d7f27102SMichael Tuexen * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16d7f27102SMichael Tuexen * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17d7f27102SMichael Tuexen * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18d7f27102SMichael Tuexen * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19d7f27102SMichael Tuexen * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20d7f27102SMichael Tuexen * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21d7f27102SMichael Tuexen * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22d7f27102SMichael Tuexen * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23d7f27102SMichael Tuexen * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24d7f27102SMichael Tuexen * SUCH DAMAGE.
25d7f27102SMichael Tuexen *
26d7f27102SMichael Tuexen */
27d7f27102SMichael Tuexen
28d7f27102SMichael Tuexen#include <machine/asm.h>
29d7f27102SMichael Tuexen__FBSDID("$FreeBSD$");
30*0ec3e991SAndrew Turner
31*0ec3e991SAndrew Turner.arch_extension crc
32d7f27102SMichael Tuexen
33d7f27102SMichael Tuexen/*
34d7f27102SMichael Tuexen * uint32_t
35d7f27102SMichael Tuexen * armv8_crc32c(uint32_t crc, const unsigned char *buf, unsigned int len)
36d7f27102SMichael Tuexen */
37d7f27102SMichael Tuexen
38d7f27102SMichael TuexenENTRY(armv8_crc32c)
39d7f27102SMichael Tuexen	cbz	w2, end
40d7f27102SMichael Tuexen	tbz	x1, #0x0, half_word_aligned
41d7f27102SMichael Tuexen	sub	w2, w2, 0x1
42d7f27102SMichael Tuexen	ldr	w10, [x1], #0x1
43d7f27102SMichael Tuexen	crc32cb	w0, w0, w10
44d7f27102SMichael Tuexenhalf_word_aligned:
45d7f27102SMichael Tuexen	cmp	w2, #0x2
46d7f27102SMichael Tuexen	b.lo	last_byte
47d7f27102SMichael Tuexen	tbz	x1, #0x1, word_aligned
48d7f27102SMichael Tuexen	sub	w2, w2, 0x2
49d7f27102SMichael Tuexen	ldr	w10, [x1], #0x2
50d7f27102SMichael Tuexen	crc32ch	w0, w0, w10
51d7f27102SMichael Tuexenword_aligned:
52d7f27102SMichael Tuexen	cmp	w2, #0x4
53d7f27102SMichael Tuexen	b.lo	last_half_word
54d7f27102SMichael Tuexen	tbz	x1, #0x2, double_word_aligned
55d7f27102SMichael Tuexen	sub	w2, w2, 0x4
56d7f27102SMichael Tuexen	ldr	w10, [x1], #0x4
57d7f27102SMichael Tuexen	crc32cw	w0, w0, w10
58d7f27102SMichael Tuexendouble_word_aligned:
59d7f27102SMichael Tuexen	lsr	w9, w2, #0x3
60d7f27102SMichael Tuexen	cbz	w9, last_word
61d7f27102SMichael Tuexenloop:
62d7f27102SMichael Tuexen	ldr	x10, [x1], #0x8
63d7f27102SMichael Tuexen	crc32cx	w0, w0, x10
64d7f27102SMichael Tuexen	subs	w9, w9, #1
65d7f27102SMichael Tuexen	b.ne	loop
66d7f27102SMichael Tuexenlast_word:
67d7f27102SMichael Tuexen	tbz	w2, #0x2, last_half_word
68d7f27102SMichael Tuexen	ldr	w10, [x1], #0x4
69d7f27102SMichael Tuexen	crc32cw	w0, w0, w10
70d7f27102SMichael Tuexenlast_half_word:
71d7f27102SMichael Tuexen	tbz	w2, #0x1, last_byte
72d7f27102SMichael Tuexen	ldr	w10, [x1], #0x2
73d7f27102SMichael Tuexen	crc32ch	w0, w0, w10
74d7f27102SMichael Tuexenlast_byte:
75d7f27102SMichael Tuexen	tbz	w2, #0x0, end
76d7f27102SMichael Tuexen	ldr	w10, [x1], #0x1
77d7f27102SMichael Tuexen	crc32cb	w0, w0, w10
78d7f27102SMichael Tuexenend:
79d7f27102SMichael Tuexen	ret
80d7f27102SMichael TuexenEND(armv8_crc32c)
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