/*-
* Copyright (c) 2017 Michael Tuexen
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include <machine/asm.h>
.arch_extension crc
/*
* uint32_t
* armv8_crc32c(uint32_t crc, const unsigned char *buf, unsigned int len)
*/
ENTRY(armv8_crc32c)
cbz w2, end
tbz x1, #0x0, half_word_aligned
sub w2, w2, 0x1
ldr w10, [x1], #0x1
crc32cb w0, w0, w10
half_word_aligned:
cmp w2, #0x2
b.lo last_byte
tbz x1, #0x1, word_aligned
sub w2, w2, 0x2
ldr w10, [x1], #0x2
crc32ch w0, w0, w10
word_aligned:
cmp w2, #0x4
b.lo last_half_word
tbz x1, #0x2, double_word_aligned
sub w2, w2, 0x4
ldr w10, [x1], #0x4
crc32cw w0, w0, w10
double_word_aligned:
lsr w9, w2, #0x3
cbz w9, last_word
loop:
ldr x10, [x1], #0x8
crc32cx w0, w0, x10
subs w9, w9, #1
b.ne loop
last_word:
tbz w2, #0x2, last_half_word
ldr w10, [x1], #0x4
crc32cw w0, w0, w10
last_half_word:
tbz w2, #0x1, last_byte
ldr w10, [x1], #0x2
crc32ch w0, w0, w10
last_byte:
tbz w2, #0x0, end
ldr w10, [x1], #0x1
crc32cb w0, w0, w10
end:
ret
END(armv8_crc32c)
plain