Source to 321/client/x86.c
/*
Copyright (C) 1997-2001 Id Software, Inc.
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.
*/
#include <stdlib.h>
#include "client.h"
#if id386
static unsigned long bias;
static unsigned long *histogram;
static unsigned long start, range;
static unsigned long bias;
__declspec( naked ) void x86_TimerStart( void )
{
__asm _emit 0fh
__asm _emit 31h
__asm mov start, eax
__asm ret
}
__declspec( naked ) void x86_TimerStop( void )
{
__asm push edi
__asm mov edi, histogram
__asm _emit 0fh
__asm _emit 31h
__asm sub eax, start
__asm sub eax, bias
__asm js discard
__asm cmp eax, range
__asm jge discard
__asm lea edi, [edi + eax*4]
__asm inc dword ptr [edi]
discard:
__asm pop edi
__asm ret
}
#pragma warning( disable: 4035 )
static __declspec( naked ) unsigned long x86_TimerStopBias( void )
{
__asm push edi
__asm mov edi, histogram
__asm _emit 0fh
__asm _emit 31h
__asm sub eax, start
__asm pop edi
__asm ret
}
#pragma warning( default:4035 )
void x86_TimerInit( unsigned long smallest, unsigned length )
{
int i;
unsigned long biastable[100];
range = length;
bias = 10000;
for ( i = 0; i < 100; i++ )
{
x86_TimerStart();
biastable[i] = x86_TimerStopBias();
if ( bias > biastable[i] )
bias = biastable[i];
}
bias += smallest;
histogram = Z_Malloc( range * sizeof( unsigned long ) );
}