You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 

81 lines
2.0 KiB

/*==LICENSE==*
CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011 Cyan Worlds, 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 3 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, see <http://www.gnu.org/licenses/>.
You can contact Cyan Worlds, Inc. by email legal@cyan.com
or by snail mail at:
Cyan Worlds, Inc.
14617 N Newport Hwy
Mead, WA 99021
*==LICENSE==*/
/*****************************************************************************
*
* $/Plasma20/Sources/Plasma/NucleusLib/pnUtils/Private/pnUtMath.cpp
*
***/
#include "../Pch.h"
#pragma hdrstop
/*****************************************************************************
*
* Exported bit manipulation functions
*
***/
//===========================================================================
#ifndef _M_IX86
unsigned MathHighBitPos (dword val) {
ASSERT(val);
double f = (double)val;
return (*((dword *)&f + 1) >> 20) - 1023;
}
#else
__declspec(naked) unsigned __fastcall MathHighBitPos (dword) {
__asm {
bsr eax, ecx
ret 0
};
}
#endif
//===========================================================================
#ifndef _M_IX86
unsigned MathLowBitPos (dword val) {
val &= ~(val - 1); // clear all but the low bit
ASSERT(val);
double f = (double)val;
return (*((dword *)&f + 1) >> 20) - 1023;
}
#else
__declspec(naked) unsigned __fastcall MathLowBitPos (dword) {
__asm {
bsf eax, ecx
ret 0
};
}
#endif