xref: /freebsd/sys/libkern/arm64/crc32c_armv8.S (revision b0d29bc47dba79f6f38e67eabadfb4b32ffd9390)
1/*-
2 * Copyright (c) 2017 Michael Tuexen
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 */
27
28#include <machine/asm.h>
29__FBSDID("$FreeBSD$");
30.arch armv8-a+crc
31
32/*
33 * uint32_t
34 * armv8_crc32c(uint32_t crc, const unsigned char *buf, unsigned int len)
35 */
36
37ENTRY(armv8_crc32c)
38	cbz	w2, end
39	tbz	x1, #0x0, half_word_aligned
40	sub	w2, w2, 0x1
41	ldr	w10, [x1], #0x1
42	crc32cb	w0, w0, w10
43half_word_aligned:
44	cmp	w2, #0x2
45	b.lo	last_byte
46	tbz	x1, #0x1, word_aligned
47	sub	w2, w2, 0x2
48	ldr	w10, [x1], #0x2
49	crc32ch	w0, w0, w10
50word_aligned:
51	cmp	w2, #0x4
52	b.lo	last_half_word
53	tbz	x1, #0x2, double_word_aligned
54	sub	w2, w2, 0x4
55	ldr	w10, [x1], #0x4
56	crc32cw	w0, w0, w10
57double_word_aligned:
58	lsr	w9, w2, #0x3
59	cbz	w9, last_word
60loop:
61	ldr	x10, [x1], #0x8
62	crc32cx	w0, w0, x10
63	subs	w9, w9, #1
64	b.ne	loop
65last_word:
66	tbz	w2, #0x2, last_half_word
67	ldr	w10, [x1], #0x4
68	crc32cw	w0, w0, w10
69last_half_word:
70	tbz	w2, #0x1, last_byte
71	ldr	w10, [x1], #0x2
72	crc32ch	w0, w0, w10
73last_byte:
74	tbz	w2, #0x0, end
75	ldr	w10, [x1], #0x1
76	crc32cb	w0, w0, w10
77end:
78	ret
79END(armv8_crc32c)
80