cosmopolitan/libc/nexgen32e/crc32c.S

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/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
2020-06-15 14:18:57 +00:00
vi: set et ft=asm ts=8 tw=8 fenc=utf-8 :vi
Copyright 2020 Justine Alexandra Roberts Tunney
This program is free software; you can redistribute it and/or modify │
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License. │
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of │
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software │
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
#include "libc/dce.h"
#include "libc/macros.h"
#include "libc/nexgen32e/x86feature.h"
#include "libc/notice.inc"
/ Computes 32-bit Castagnoli Cyclic Redundancy Check.
/
/ @param edi is the initial hash value (0 is fine)
/ @param rsi points to the data
/ @param rdx is the byte size of data
/ @return eax is the new hash value
/ @note Used by ISCSI, TensorFlow, etc.
.initbss 300,_init_crc32c
crc32c: .quad 0
.endobj crc32c,globl
.previous
.init.start 300,_init_crc32c
ezlea crc32c$pure,ax
ezlea crc32c$sse42,cx
testb X86_HAVE(SSE4_2)+kCpuids(%rip)
cmovnz %rcx,%rax
stosq
.init.end 300,_init_crc32c
.source __FILE__