libosmocore  0.9.3.20160317
Osmocom core library
bits.h
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1 #pragma once
2 
3 #include <stdint.h>
4 #include <stddef.h>
5 
6 #include <osmocom/core/bit16gen.h>
7 #include <osmocom/core/bit32gen.h>
8 #include <osmocom/core/bit64gen.h>
9 
18 typedef int8_t sbit_t;
19 typedef uint8_t ubit_t;
20 typedef uint8_t pbit_t;
22 /*
23  NOTE on the endianess of pbit_t:
24  Bits in a pbit_t are ordered MSB first, i.e. 0x80 is the first bit.
25  Bit i in a pbit_t array is array[i/8] & (1<<(7-i%8))
26 */
27 
31 static inline unsigned int osmo_pbit_bytesize(unsigned int num_bits)
32 {
33  unsigned int pbit_bytesize = num_bits / 8;
34 
35  if (num_bits % 8)
36  pbit_bytesize++;
37 
38  return pbit_bytesize;
39 }
40 
41 int osmo_ubit2pbit(pbit_t *out, const ubit_t *in, unsigned int num_bits);
42 
43 int osmo_pbit2ubit(ubit_t *out, const pbit_t *in, unsigned int num_bits);
44 
45 int osmo_ubit2pbit_ext(pbit_t *out, unsigned int out_ofs,
46  const ubit_t *in, unsigned int in_ofs,
47  unsigned int num_bits, int lsb_mode);
48 
49 int osmo_pbit2ubit_ext(ubit_t *out, unsigned int out_ofs,
50  const pbit_t *in, unsigned int in_ofs,
51  unsigned int num_bits, int lsb_mode);
52 
53 #define OSMO_BIN_SPEC "%d%d%d%d%d%d%d%d"
54 #define OSMO_BIN_PRINT(byte) \
55  (byte & 0x80 ? 1 : 0), \
56  (byte & 0x40 ? 1 : 0), \
57  (byte & 0x20 ? 1 : 0), \
58  (byte & 0x10 ? 1 : 0), \
59  (byte & 0x08 ? 1 : 0), \
60  (byte & 0x04 ? 1 : 0), \
61  (byte & 0x02 ? 1 : 0), \
62  (byte & 0x01 ? 1 : 0)
63 
64 #define OSMO_BIT_SPEC "%c%c%c%c%c%c%c%c"
65 #define OSMO_BIT_PRINT(byte) \
66  (byte & 0x80 ? '1' : '.'), \
67  (byte & 0x40 ? '1' : '.'), \
68  (byte & 0x20 ? '1' : '.'), \
69  (byte & 0x10 ? '1' : '.'), \
70  (byte & 0x08 ? '1' : '.'), \
71  (byte & 0x04 ? '1' : '.'), \
72  (byte & 0x02 ? '1' : '.'), \
73  (byte & 0x01 ? '1' : '.')
74 
75 /* BIT REVERSAL */
76 
78 enum osmo_br_mode {
80  OSMO_BR_BITS_IN_DWORD = 31,
82  OSMO_BR_BYTES_IN_DWORD = 24,
84  OSMO_BR_BITS_IN_BYTE = 7,
86  OSMO_BR_WORD_SWAP = 16,
87 };
88 
90 uint32_t osmo_bit_reversal(uint32_t x, enum osmo_br_mode k);
91 
92 /* \brief reverse the bits within each byte of a 32bit word */
93 uint32_t osmo_revbytebits_32(uint32_t x);
94 
95 /* \brief reverse the bits within a byte */
96 uint32_t osmo_revbytebits_8(uint8_t x);
97 
98 /* \brief reverse the bits of each byte in a given buffer */
99 void osmo_revbytebits_buf(uint8_t *buf, int len);
100 
106 static inline uint16_t osmo_rol16(uint16_t in, unsigned shift)
107 {
108  return (in << shift) | (in >> (16 - shift));
109 }
110