blob: 3fa34f51b3cd8a306234807079586b9cddbee6aa (
plain) (
tree)
|
|
// license:BSD-3-Clause
// copyright-holders:Aaron Giles
//============================================================
//
// eivc.h
//
// Inline implementations for MSVC compiler.
//
//============================================================
#ifndef MAME_OSD_EIVC_H
#define MAME_OSD_EIVC_H
#pragma once
#include <intrin.h>
#pragma intrinsic(_BitScanReverse)
/***************************************************************************
INLINE BIT MANIPULATION FUNCTIONS
***************************************************************************/
/*-------------------------------------------------
count_leading_zeros - return the number of
leading zero bits in a 32-bit value
-------------------------------------------------*/
#ifndef count_leading_zeros
#define count_leading_zeros _count_leading_zeros
inline uint8_t _count_leading_zeros(uint32_t value)
{
unsigned long index;
return _BitScanReverse(&index, value) ? (31U - index) : 32U;
}
#endif
/*-------------------------------------------------
count_leading_ones - return the number of
leading one bits in a 32-bit value
-------------------------------------------------*/
#ifndef count_leading_ones
#define count_leading_ones _count_leading_ones
inline uint8_t _count_leading_ones(uint32_t value)
{
unsigned long index;
return _BitScanReverse(&index, ~value) ? (31U - index) : 32U;
}
#endif
#endif // MAME_OSD_EIVC_H
|