ceph/src/spdk/isa-l/igzip/bitbuf2.h

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   2   Copyright(c) 2011-2016 Intel Corporation All rights reserved.
   3
   4   Redistribution and use in source and binary forms, with or without
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   8       notice, this list of conditions and the following disclaimer.
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  10       notice, this list of conditions and the following disclaimer in
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  15       from this software without specific prior written permission.
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  17   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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  28 **********************************************************************/
  29 #ifndef BITBUF2_H
  30 #define BITBUF2_H
  31
  32 #include "igzip_lib.h"
  33
  34 #if defined (__unix__) || (__APPLE__) || (__MINGW32__)
  35 #define _mm_stream_si64x(dst, src) *((uint64_t*)dst) = src
  36 #else
  37 #include <intrin.h>
  38 #endif
  39
  40 #ifdef _WIN64
  41 #pragma warning(disable: 4996)
  42 #endif
  43
  44 #ifdef _MSC_VER
  45 #define inline __inline
  46 #endif
  47
  48
  49 /* MAX_BITBUF_BIT WRITE is the maximum number of bits than can be safely written
  50  * by consecutive calls of write_bits. Note this assumes the bitbuf is in a
  51  * state that is possible at the exit of write_bits */
  52 #define MAX_BITBUF_BIT_WRITE 56
  53
  54 static inline void init(struct BitBuf2 *me)
  55 {
  56         me->m_bits = 0;
  57         me->m_bit_count = 0;
  58 }
  59
  60 static inline void set_buf(struct BitBuf2 *me, unsigned char *buf, unsigned int len)
  61 {
  62         unsigned int slop = 8;
  63         me->m_out_buf = me->m_out_start = buf;
  64         me->m_out_end = buf + len - slop;
  65 }
  66
  67 static inline int is_full(struct BitBuf2 *me)
  68 {
  69         return (me->m_out_buf > me->m_out_end);
  70 }
  71
  72 static inline uint8_t * buffer_ptr(struct BitBuf2 *me)
  73 {
  74         return me->m_out_buf;
  75 }
  76
  77 static inline uint32_t buffer_used(struct BitBuf2 *me)
  78 {
  79         return (uint32_t)(me->m_out_buf - me->m_out_start);
  80 }
  81
  82 static inline uint32_t buffer_bits_used(struct BitBuf2 *me)
  83 {
  84         return (8 * (uint32_t)(me->m_out_buf - me->m_out_start) + me->m_bit_count);
  85 }
  86
  87 static inline void flush_bits(struct BitBuf2 *me)
  88 {
  89         uint32_t bits;
  90         _mm_stream_si64x((int64_t *) me->m_out_buf, me->m_bits);
  91         bits = me->m_bit_count & ~7;
  92         me->m_bit_count -= bits;
  93         me->m_out_buf += bits/8;
  94         me->m_bits >>= bits;
  95
  96 }
  97
  98 /* Can write up to 8 bytes to output buffer */
  99 static inline void flush(struct BitBuf2 *me)
 100 {
 101         uint32_t bytes;
 102         if (me->m_bit_count) {
 103                 _mm_stream_si64x((int64_t *) me->m_out_buf, me->m_bits);
 104                 bytes = (me->m_bit_count + 7) / 8;
 105                 me->m_out_buf += bytes;
 106         }
 107         me->m_bits = 0;
 108         me->m_bit_count = 0;
 109 }
 110
 111 static inline void check_space(struct BitBuf2 *me, uint32_t num_bits)
 112 {
 113         /* Checks if bitbuf has num_bits extra space and flushes the bytes in
 114          * the bitbuf if it doesn't. */
 115         if (63 - me->m_bit_count < num_bits)
 116                 flush_bits(me);
 117 }
 118
 119 static inline void write_bits_unsafe(struct BitBuf2 *me, uint64_t code, uint32_t count)
 120 {
 121         me->m_bits |= code << me->m_bit_count;
 122         me->m_bit_count += count;
 123 }
 124
 125 static inline void write_bits(struct BitBuf2 *me, uint64_t code, uint32_t count)
 126 {       /* Assumes there is space to fit code into m_bits. */
 127         me->m_bits |= code << me->m_bit_count;
 128         me->m_bit_count += count;
 129         flush_bits(me);
 130 }
 131
 132 static inline void write_bits_flush(struct BitBuf2 *me, uint64_t code, uint32_t count)
 133 {       /* Assumes there is space to fit code into m_bits. */
 134         me->m_bits |= code << me->m_bit_count;
 135         me->m_bit_count += count;
 136         flush(me);
 137 }
 138
 139 #endif //BITBUF2_H