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/*
* Copyright (C) 2014 Freie Universität Berlin
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @addtogroup core_util
* @{
*
* @file
* @brief Helper functions for bit arithmetic
*
* @author Kaspar Schleiser <kaspar@schleiser.de>
* @author Martine Lenders <mlenders@inf.fu-berlin.de>
*/
#ifndef BITARITHM_H
#define BITARITHM_H
#ifdef __cplusplus
extern "C" {
#endif
/**
* @def SETBIT
* @brief Sets a bitmask for a bitfield
*
* @param[in] val The bitfield
* @param[in] bit Specifies the bits to be set
*
* @return The modified bitfield
*/
#define SETBIT(val, bit) val |= (bit)
/**
* @def CLRBIT
* @brief Clears bitmask for a bitfield
*
* @param[in] val The bitfield
* @param[in] bit Specifies the bits to be cleared
*
* @return The modified bitfield
*/
#define CLRBIT(val, bit) val &= (~(bit))
/**
* @name Single Bit Defines
* @{
*/
#ifndef BIT0
#define BIT0 0x00000001
#define BIT1 0x00000002
#define BIT2 0x00000004
#define BIT3 0x00000008
#define BIT4 0x00000010
#define BIT5 0x00000020
#define BIT6 0x00000040
#define BIT7 0x00000080
#define BIT8 0x00000100
#define BIT9 0x00000200
#define BIT10 0x00000400
#define BIT11 0x00000800
#define BIT12 0x00001000
#define BIT13 0x00002000
#define BIT14 0x00004000
#define BIT15 0x00008000
#endif
#ifndef BIT16
#define BIT16 0x00010000
#define BIT17 0x00020000
#define BIT18 0x00040000
#define BIT19 0x00080000
#define BIT20 0x00100000
#define BIT21 0x00200000
#define BIT22 0x00400000
#define BIT23 0x00800000
#define BIT24 0x01000000
#define BIT25 0x02000000
#define BIT26 0x04000000
#define BIT27 0x08000000
#define BIT28 0x10000000
#define BIT29 0x20000000
#define BIT30 0x40000000
#define BIT31 0x80000000
#endif
/** @} */
#define ARCH_32_BIT (__INT_MAX__ == 2147483647) /**< 1 for 32 bit architectures, 0 otherwise */
/**
* @brief Returns the number of the highest '1' bit in a value
* @param[in] v Input value
* @return Bit Number
*
* Source: http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogObvious
*/
unsigned bitarithm_msb(unsigned v);
/**
* @brief Returns the number of the lowest '1' bit in a value
* @param[in] v Input value - must be unequal to '0', otherwise the
* function will produce an infinite loop
* @return Bit Number
*
* Source: http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogObvious
*/
unsigned bitarithm_lsb(register unsigned v);
/**
* @brief Returns the number of bits set in a value
* @param[in] v Input value
* @return Number of set bits
*
* Source: http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogObvious
*/
unsigned bitarithm_bits_set(unsigned v);
#ifdef __cplusplus
}
#endif
#endif /* BITARITHM_H */
/** @} */