Neels Hofmeyr | 17518fe | 2017-06-20 04:35:06 +0200 | [diff] [blame] | 1 | /*! \file bits.h |
| 2 | * Osmocom bit level support code. |
| 3 | * |
Neels Hofmeyr | 17518fe | 2017-06-20 04:35:06 +0200 | [diff] [blame] | 4 | */ |
| 5 | |
Sylvain Munaut | 12ba778 | 2014-06-16 10:13:40 +0200 | [diff] [blame] | 6 | #pragma once |
Harald Welte | 2230c13 | 2011-01-19 10:10:16 +0100 | [diff] [blame] | 7 | |
| 8 | #include <stdint.h> |
Max | 5377701 | 2014-06-04 19:07:41 +0200 | [diff] [blame] | 9 | #include <stddef.h> |
| 10 | |
| 11 | #include <osmocom/core/bit16gen.h> |
| 12 | #include <osmocom/core/bit32gen.h> |
| 13 | #include <osmocom/core/bit64gen.h> |
Harald Welte | 2230c13 | 2011-01-19 10:10:16 +0100 | [diff] [blame] | 14 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 15 | /*! \defgroup bits soft, unpacked and packed bits |
| 16 | * @{ |
Neels Hofmeyr | 17518fe | 2017-06-20 04:35:06 +0200 | [diff] [blame] | 17 | * \file bits.h */ |
Harald Welte | bd598e3 | 2011-08-16 23:26:52 +0200 | [diff] [blame] | 18 | |
Harald Welte | ef7a44e | 2017-10-16 14:18:17 +0200 | [diff] [blame] | 19 | /*! soft bit with value (-127...127), as commonly used in |
| 20 | * communications receivers such as [viterbi] decoders */ |
| 21 | typedef int8_t sbit_t; |
| 22 | |
| 23 | /*! unpacked bit (0 or 1): 1 bit per byte */ |
| 24 | typedef uint8_t ubit_t; |
| 25 | |
| 26 | /*! packed bits (8 bits in a byte). |
| 27 | * NOTE on the endian-ness of \ref pbit_t: |
| 28 | * - Bits in a \ref pbit_t are ordered MSB first, i.e. 0x80 is the first bit. |
| 29 | * - Bit i in a \ref pbit_t array is array[i/8] & (1<<(7-i%8)) */ |
| 30 | typedef uint8_t pbit_t; |
Harald Welte | 2230c13 | 2011-01-19 10:10:16 +0100 | [diff] [blame] | 31 | |
Neels Hofmeyr | 87e4550 | 2017-06-20 00:17:59 +0200 | [diff] [blame] | 32 | /*! determine how many bytes we would need for \a num_bits packed bits |
Harald Welte | bd598e3 | 2011-08-16 23:26:52 +0200 | [diff] [blame] | 33 | * \param[in] num_bits Number of packed bits |
Harald Welte | 2d2e2cc | 2016-04-25 12:11:20 +0200 | [diff] [blame] | 34 | * \returns number of bytes needed for \a num_bits packed bits |
Harald Welte | bd598e3 | 2011-08-16 23:26:52 +0200 | [diff] [blame] | 35 | */ |
Harald Welte | 2230c13 | 2011-01-19 10:10:16 +0100 | [diff] [blame] | 36 | static inline unsigned int osmo_pbit_bytesize(unsigned int num_bits) |
| 37 | { |
| 38 | unsigned int pbit_bytesize = num_bits / 8; |
| 39 | |
| 40 | if (num_bits % 8) |
| 41 | pbit_bytesize++; |
| 42 | |
| 43 | return pbit_bytesize; |
| 44 | } |
| 45 | |
Harald Welte | 2230c13 | 2011-01-19 10:10:16 +0100 | [diff] [blame] | 46 | int osmo_ubit2pbit(pbit_t *out, const ubit_t *in, unsigned int num_bits); |
| 47 | |
Harald Welte | 2230c13 | 2011-01-19 10:10:16 +0100 | [diff] [blame] | 48 | int osmo_pbit2ubit(ubit_t *out, const pbit_t *in, unsigned int num_bits); |
| 49 | |
Max | e0a7d9e | 2016-06-17 17:58:52 +0200 | [diff] [blame] | 50 | void osmo_nibble_shift_right(uint8_t *out, const uint8_t *in, |
| 51 | unsigned int num_nibbles); |
| 52 | void osmo_nibble_shift_left_unal(uint8_t *out, const uint8_t *in, |
| 53 | unsigned int num_nibbles); |
| 54 | |
Max | d8fb142 | 2016-04-06 16:13:00 +0200 | [diff] [blame] | 55 | void osmo_ubit2sbit(sbit_t *out, const ubit_t *in, unsigned int num_bits); |
| 56 | void osmo_sbit2ubit(ubit_t *out, const sbit_t *in, unsigned int num_bits); |
| 57 | |
Sylvain Munaut | aeb1077 | 2011-01-21 12:22:30 +0100 | [diff] [blame] | 58 | int osmo_ubit2pbit_ext(pbit_t *out, unsigned int out_ofs, |
| 59 | const ubit_t *in, unsigned int in_ofs, |
| 60 | unsigned int num_bits, int lsb_mode); |
| 61 | |
Sylvain Munaut | aeb1077 | 2011-01-21 12:22:30 +0100 | [diff] [blame] | 62 | int osmo_pbit2ubit_ext(ubit_t *out, unsigned int out_ofs, |
| 63 | const pbit_t *in, unsigned int in_ofs, |
| 64 | unsigned int num_bits, int lsb_mode); |
| 65 | |
Max | 6a5ef46 | 2016-02-24 16:05:48 +0100 | [diff] [blame] | 66 | #define OSMO_BIN_SPEC "%d%d%d%d%d%d%d%d" |
| 67 | #define OSMO_BIN_PRINT(byte) \ |
| 68 | (byte & 0x80 ? 1 : 0), \ |
| 69 | (byte & 0x40 ? 1 : 0), \ |
| 70 | (byte & 0x20 ? 1 : 0), \ |
| 71 | (byte & 0x10 ? 1 : 0), \ |
| 72 | (byte & 0x08 ? 1 : 0), \ |
| 73 | (byte & 0x04 ? 1 : 0), \ |
| 74 | (byte & 0x02 ? 1 : 0), \ |
| 75 | (byte & 0x01 ? 1 : 0) |
| 76 | |
| 77 | #define OSMO_BIT_SPEC "%c%c%c%c%c%c%c%c" |
Max | a52d839 | 2017-09-12 15:34:35 +0200 | [diff] [blame] | 78 | #define OSMO_BIT_PRINT_EX(byte, ch) \ |
| 79 | (byte & 0x80 ? ch : '.'), \ |
| 80 | (byte & 0x40 ? ch : '.'), \ |
| 81 | (byte & 0x20 ? ch : '.'), \ |
| 82 | (byte & 0x10 ? ch : '.'), \ |
| 83 | (byte & 0x08 ? ch : '.'), \ |
| 84 | (byte & 0x04 ? ch : '.'), \ |
| 85 | (byte & 0x02 ? ch : '.'), \ |
| 86 | (byte & 0x01 ? ch : '.') |
| 87 | |
| 88 | #define OSMO_BIT_PRINT(byte) OSMO_BIT_PRINT_EX(byte, '1') |
Harald Welte | 712691d | 2011-09-01 14:47:31 +0200 | [diff] [blame] | 89 | |
| 90 | /* BIT REVERSAL */ |
| 91 | |
Neels Hofmeyr | 87e4550 | 2017-06-20 00:17:59 +0200 | [diff] [blame] | 92 | /*! bit-reversal mode for osmo_bit_reversal() */ |
Harald Welte | 712691d | 2011-09-01 14:47:31 +0200 | [diff] [blame] | 93 | enum osmo_br_mode { |
Neels Hofmeyr | 87e4550 | 2017-06-20 00:17:59 +0200 | [diff] [blame] | 94 | /*! reverse all bits in a 32bit dword */ |
Harald Welte | 712691d | 2011-09-01 14:47:31 +0200 | [diff] [blame] | 95 | OSMO_BR_BITS_IN_DWORD = 31, |
Neels Hofmeyr | 87e4550 | 2017-06-20 00:17:59 +0200 | [diff] [blame] | 96 | /*! reverse byte order in a 32bit dword */ |
Harald Welte | 712691d | 2011-09-01 14:47:31 +0200 | [diff] [blame] | 97 | OSMO_BR_BYTES_IN_DWORD = 24, |
Neels Hofmeyr | 87e4550 | 2017-06-20 00:17:59 +0200 | [diff] [blame] | 98 | /*! reverse bits of each byte in a 32bit dword */ |
Harald Welte | 712691d | 2011-09-01 14:47:31 +0200 | [diff] [blame] | 99 | OSMO_BR_BITS_IN_BYTE = 7, |
Neels Hofmeyr | 87e4550 | 2017-06-20 00:17:59 +0200 | [diff] [blame] | 100 | /*! swap the two 16bit words in a 32bit dword */ |
Harald Welte | 712691d | 2011-09-01 14:47:31 +0200 | [diff] [blame] | 101 | OSMO_BR_WORD_SWAP = 16, |
| 102 | }; |
| 103 | |
Harald Welte | 712691d | 2011-09-01 14:47:31 +0200 | [diff] [blame] | 104 | uint32_t osmo_bit_reversal(uint32_t x, enum osmo_br_mode k); |
| 105 | |
Harald Welte | 712691d | 2011-09-01 14:47:31 +0200 | [diff] [blame] | 106 | uint32_t osmo_revbytebits_32(uint32_t x); |
| 107 | |
Harald Welte | 712691d | 2011-09-01 14:47:31 +0200 | [diff] [blame] | 108 | uint32_t osmo_revbytebits_8(uint8_t x); |
| 109 | |
Harald Welte | 712691d | 2011-09-01 14:47:31 +0200 | [diff] [blame] | 110 | void osmo_revbytebits_buf(uint8_t *buf, int len); |
| 111 | |
Neels Hofmeyr | 87e4550 | 2017-06-20 00:17:59 +0200 | [diff] [blame] | 112 | /*! left circular shift |
Max | e2c1390 | 2014-06-04 19:07:42 +0200 | [diff] [blame] | 113 | * \param[in] in The 16 bit unsigned integer to be rotated |
| 114 | * \param[in] shift Number of bits to shift \a in to, [0;16] bits |
| 115 | * \returns shifted value |
| 116 | */ |
| 117 | static inline uint16_t osmo_rol16(uint16_t in, unsigned shift) |
| 118 | { |
| 119 | return (in << shift) | (in >> (16 - shift)); |
| 120 | } |
| 121 | |
Sylvain Munaut | dca7d2c | 2012-04-18 21:53:23 +0200 | [diff] [blame] | 122 | /*! @} */ |