have_mmx.s

来自「这是符合Linux操作系统标准的POIXS 的pixops-2.0.5源程序」· S 代码 · 共 61 行

/* Copyright (C) 2000 Red Hat, Inc.
 * This file is part of the Pixops Library.
 *
 * The pixops library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as published
 * by the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * The pixops library 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 Library General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

        .file	"have_mmx.S"
	.version	"01.01"
gcc2_compiled.:
.text
	.align 16
.globl pixops_have_mmx
	.type	 pixops_have_mmx,@function

pixops_have_mmx:
	push	%ebx

# Check if bit 21 in flags word is writeable

	pushfl	
	popl	%eax
	movl	%eax,%ebx
	xorl	$0x00200000, %eax
	pushl   %eax
	popfl
	pushfl
	popl	%eax

	cmpl	%eax, %ebx

	je .notfound

# OK, we have CPUID

	movl	$1, %eax
	cpuid
	
	test	$0x00800000, %edx
	jz	.notfound

	movl	$1, %eax
	jmp	.out

.notfound:
	movl  	$0, %eax
.out:	
	popl	%ebx
	ret