coregrind/x86/cpuid.S

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##--- Support for determining CPU characteristics.     x86/cpuid.S ---##
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/*
  This file is part of Valgrind, a dynamic binary instrumentation
  framework.

  Copyright (C) 2000-2005 Julian Seward 
     jseward@acm.org

  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; either version 2 of the
  License, or (at your option) any later version.

  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., 59 Temple Place, Suite 330, Boston, MA
  02111-1307, USA.

  The GNU General Public License is contained in the file COPYING.
*/

#include "pub_basics_asm.h"

/*
    Bool VG_(has_cpuid)(void)
 */
.globl VG_(has_cpuid)
VG_(has_cpuid):
        pushl   %ebp
        movl    %esp, %ebp
        pushl   %ecx
        pushfl
        pushfl
        popl    %eax
        movl    %eax, %ecx
        xorl    $0x200000, %eax
        pushl   %eax
        popfl
        pushfl
        popl    %eax
        popfl
        xorl    %ecx, %eax
        andl    $0x200000, %eax
        shrl    $21, %eax
        popl    %ecx
        movl    %ebp, %esp
        popl    %ebp
        ret

/*
    void VG_(cpuid)(UInt eax,
                    UInt *eax_ret, UInt *ebx_ret, UInt *ecx_ret, UInt *edx_ret)
 */
.globl VG_(cpuid)
VG_(cpuid):
        pushl   %ebp
        movl    %esp, %ebp
        pushl   %eax
        pushl   %ebx
        pushl   %ecx
        pushl   %edx
        pushl   %esi
        movl    8(%ebp), %eax
        cpuid
        movl    12(%ebp), %esi
        testl   %esi, %esi
        jz      1f
        movl    %eax, (%esi)
1:
        movl    16(%ebp), %esi
        testl   %esi, %esi
        jz      2f
        movl    %ebx, (%esi)
2:
        movl    20(%ebp), %esi
        testl   %esi, %esi
        jz      3f
        movl    %ecx, (%esi)
3:
        movl    24(%ebp), %esi
        testl   %esi, %esi
        jz      4f
        movl    %edx, (%esi)
4:
        popl    %esi
        popl    %edx
        popl    %ecx
        popl    %ebx
        popl    %eax
        movl    %ebp, %esp
        popl    %ebp
        ret
        
/* Let the linker know we don't need an executable stack */
.section .note.GNU-stack,"",@progbits

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