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RIOT/core/include/bitarithm.h
Oliver Hahm f38f32f6cc * added support for sht11 for msb-430-common
* fixed some jamfile isssues for msb-430
* fixed arch32 detection for scheduler
* changed sht11 driver to be platform independent
2010-10-29 17:32:03 +02:00

101 lines
2.4 KiB
C

/**
* Helper functions for bit arithmetic
*
* Copyright (C) 2010 Freie Universität Berlin
*
* This file subject to the terms and conditions of the GNU General Public
* License. See the file LICENSE in the top level directory for more details.
*
* @defgroup bitarithm Bit Arithmetic
* @ingroup lib
* @{
* @file
* @author Freie Universität Berlin, Computer Systems & Telematics, FeuerWhere project
* @author Kaspar Schleiser <kaspar.schleiser@fu-berlin.de>
*/
#ifndef BITARITHM_H_
#define BITARITHM_H_
#define BS(val, bit) ((val) & (bit))
#define BS_COND(condition, target, mask) (target) ^= ( (-(condition) ^ (target)) & (mask) )
#define SETBIT(val, bit) val |= (bit)
#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)
/**
* @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 number_of_highest_bit(unsigned v);
/**
* @brief Returns the number of the lowest '1' bit in a value
* @param[in] v Input value
* @return Bit Number
*
* Source: http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogObvious
*/
unsigned number_of_lowest_bit(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 number_of_bits_set(unsigned v);
/**
* @}
*/
#endif /* BITARITHM_H_ */