xref: /freebsd/sys/libkern/arm64/crc32c_armv8.S (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
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#include <sys/elf_common.h>
30
31.arch_extension crc
32
33/*
34 * uint32_t
35 * armv8_crc32c(uint32_t crc, const unsigned char *buf, unsigned int len)
36 */
37
38ENTRY(armv8_crc32c)
39	cbz	w2, end
40	tbz	x1, #0x0, half_word_aligned
41	sub	w2, w2, 0x1
42	ldr	w10, [x1], #0x1
43	crc32cb	w0, w0, w10
44half_word_aligned:
45	cmp	w2, #0x2
46	b.lo	last_byte
47	tbz	x1, #0x1, word_aligned
48	sub	w2, w2, 0x2
49	ldr	w10, [x1], #0x2
50	crc32ch	w0, w0, w10
51word_aligned:
52	cmp	w2, #0x4
53	b.lo	last_half_word
54	tbz	x1, #0x2, double_word_aligned
55	sub	w2, w2, 0x4
56	ldr	w10, [x1], #0x4
57	crc32cw	w0, w0, w10
58double_word_aligned:
59	lsr	w9, w2, #0x3
60	cbz	w9, last_word
61loop:
62	ldr	x10, [x1], #0x8
63	crc32cx	w0, w0, x10
64	subs	w9, w9, #1
65	b.ne	loop
66last_word:
67	tbz	w2, #0x2, last_half_word
68	ldr	w10, [x1], #0x4
69	crc32cw	w0, w0, w10
70last_half_word:
71	tbz	w2, #0x1, last_byte
72	ldr	w10, [x1], #0x2
73	crc32ch	w0, w0, w10
74last_byte:
75	tbz	w2, #0x0, end
76	ldr	w10, [x1], #0x1
77	crc32cb	w0, w0, w10
78end:
79	ret
80END(armv8_crc32c)
81
82GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)
83