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/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
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/nexgen32e/x86feature.h"
#include "libc/macros.h"
.text.startup
/ Initializes jump table for memset() and memcpy().
/
/ @param !ZF if required cpu vector extensions are available
/ @param rdi is address of 64-bit jump table
/ @param rsi is address of 8-bit jump initializers
/ @param rdx is address of indirect branch
/ @param ecx is size of jump table
memjmpinit:
.leafprologue
setnz %r8b
shl %r8b
0: xor %eax,%eax
lodsb
add %rdx,%rax
stosq
.loop 0b
xor %eax,%eax
testb X86_HAVE(ERMS)+kCpuids(%rip)
setnz %al
or %r8b,%al
mov (%rsi,%rax),%al
add %rdx,%rax
stosq
lodsq
.leafepilogue
.endfn memjmpinit,globl,hidden
.source __FILE__