mirror of https://gerrit.osmocom.org/libosmocore
79 lines
2.2 KiB
C
79 lines
2.2 KiB
C
#ifndef _OSMO_BITS_H
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#define _OSMO_BITS_H
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#include <stdint.h>
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/*! \defgroup bits soft, unpacked and packed bits
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* @{
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*/
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/*! \file bits.h
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* \brief Osmocom bit level support code
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*/
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typedef int8_t sbit_t; /*!< \brief soft bit (-127...127) */
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typedef uint8_t ubit_t; /*!< \brief unpacked bit (0 or 1) */
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typedef uint8_t pbit_t; /*!< \brief packed bis (8 bits in a byte) */
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/*
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NOTE on the endianess of pbit_t:
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Bits in a pbit_t are ordered MSB first, i.e. 0x80 is the first bit.
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Bit i in a pbit_t array is array[i/8] & (1<<(7-i%8))
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*/
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/*! \brief determine how many bytes we would need for \a num_bits packed bits
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* \param[in] num_bits Number of packed bits
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*/
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static inline unsigned int osmo_pbit_bytesize(unsigned int num_bits)
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{
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unsigned int pbit_bytesize = num_bits / 8;
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if (num_bits % 8)
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pbit_bytesize++;
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return pbit_bytesize;
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}
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int osmo_ubit2pbit(pbit_t *out, const ubit_t *in, unsigned int num_bits);
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int osmo_pbit2ubit(ubit_t *out, const pbit_t *in, unsigned int num_bits);
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int osmo_ubit2pbit_ext(pbit_t *out, unsigned int out_ofs,
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const ubit_t *in, unsigned int in_ofs,
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unsigned int num_bits, int lsb_mode);
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int osmo_pbit2ubit_ext(ubit_t *out, unsigned int out_ofs,
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const pbit_t *in, unsigned int in_ofs,
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unsigned int num_bits, int lsb_mode);
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/* BIT REVERSAL */
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/*! \brief bit-reversal mode for osmo_bit_reversal() */
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enum osmo_br_mode {
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/*! \brief reverse all bits in a 32bit dword */
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OSMO_BR_BITS_IN_DWORD = 31,
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/*! \brief reverse byte order in a 32bit dword */
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OSMO_BR_BYTES_IN_DWORD = 24,
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/*! \brief reverse bits of each byte in a 32bit dword */
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OSMO_BR_BITS_IN_BYTE = 7,
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/*! \brief swap the two 16bit words in a 32bit dword */
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OSMO_BR_WORD_SWAP = 16,
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};
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/*! \brief generic bit reversal function */
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uint32_t osmo_bit_reversal(uint32_t x, enum osmo_br_mode k);
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/* \brief reverse the bits within each byte of a 32bit word */
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uint32_t osmo_revbytebits_32(uint32_t x);
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/* \brief reverse the bits within a byte */
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uint32_t osmo_revbytebits_8(uint8_t x);
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/* \brief reverse the bits of each byte in a given buffer */
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void osmo_revbytebits_buf(uint8_t *buf, int len);
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/*! }@ */
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#endif /* _OSMO_BITS_H */
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