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40 lines
659 B
C
40 lines
659 B
C
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#ifndef BITS_H
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#define BITS_H
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/**
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* Utility functions to operate on bits.
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*/
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#include <stdbool.h>
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#include <stddef.h>
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#include <stdint.h>
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/**
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* Check whether a byte has a bit set.
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*/
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static inline bool
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has_bit(uint8_t val, size_t index)
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{
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return val & (1 << index);
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}
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/**
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* Extract a bit range from a byte.
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*
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* Both offsets are inclusive, start from zero, and high must be greater than low.
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*/
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static inline uint8_t
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get_bit_range(uint8_t val, size_t high, size_t low)
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{
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size_t n;
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uint8_t bitmask;
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assert(high <= 7 && high >= low);
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n = high - low + 1;
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bitmask = (uint8_t) ((1 << n) - 1);
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return (uint8_t) (val >> low) & bitmask;
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}
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#endif
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