Files
MentOS/libc/inc/sys/bitops.h
T
2021-12-30 11:50:15 +01:00

40 lines
1.9 KiB
C

/// @file bitops.h
/// @brief Bitmasks functions.
/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
/// See LICENSE.md for details.
#pragma once
#define bit_set(V, B) ((V) | (1U << (B))) ///< Sets the given bit.
#define bit_clear(V, B) ((V) & ~(1U << (B))) ///< Clears the given bit.
#define bit_flip(V, B) ((V) ^ (1U << (B))) ///< Flips the given bit.
#define bit_set_assign(V, B) ((V) |= (1U << (B))) ///< Sets the given bit, permanently.
#define bit_clear_assign(V, B) ((V) &= ~(1U << (B))) ///< Clears the given bit, permanently.
#define bit_flip_assign(V, B) ((V) ^= (1U << (B))) ///< Flips the given bit, permanently.
#define bit_check(V, B) ((V) & (1U << (B))) ///< Checks if the given bit is 1.
#define bitmask_set(V, M) ((V) | (M)) ///< Sets the bits identified by the mask.
#define bitmask_clear(V, M) ((V) & ~(M)) ///< Clears the bits identified by the mask.
#define bitmask_flip(V, M) ((V) ^ (M)) ///< Flips the bits identified by the mask.
#define bitmask_set_assign(V, M) ((V) |= (M)) ///< Sets the bits identified by the mask, permanently.
#define bitmask_clear_assign(V, M) ((V) &= ~(M)) ///< Clears the bits identified by the mask, permanently.
#define bitmask_flip_assign(V, M) ((V) ^= (M)) ///< Flips the bits identified by the mask, permanently.
#define bitmask_check(V, M) ((V) & (M)) ///< Checks if the bits identified by the mask are all 1.
/// @brief Finds the first bit at zero, starting from the less significative bit.
static inline int find_first_zero(unsigned long value)
{
for (int i = 0; i < 32; ++i)
if (!bit_check(value, i))
return i;
return 0;
}
/// @brief Finds the first bit not zero, starting from the less significative bit.
static inline int find_first_non_zero(unsigned long value)
{
for (int i = 0; i < 32; ++i)
if (bit_check(value, i))
return i;
return 0;
}