ewah/ewok_rlw.h

   1 /**
   2  * Copyright 2013, GitHub, Inc
   3  * Copyright 2009-2013, Daniel Lemire, Cliff Moon,
   4  *      David McIntosh, Robert Becho, Google Inc. and Veronika Zenz
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version 2
   9  * of the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  19  */
  20 #ifndef __EWOK_RLW_H__
  21 #define __EWOK_RLW_H__
  22
  23 #define RLW_RUNNING_BITS (sizeof(eword_t) * 4)
  24 #define RLW_LITERAL_BITS (sizeof(eword_t) * 8 - 1 - RLW_RUNNING_BITS)
  25
  26 #define RLW_LARGEST_RUNNING_COUNT (((eword_t)1 << RLW_RUNNING_BITS) - 1)
  27 #define RLW_LARGEST_LITERAL_COUNT (((eword_t)1 << RLW_LITERAL_BITS) - 1)
  28
  29 #define RLW_LARGEST_RUNNING_COUNT_SHIFT (RLW_LARGEST_RUNNING_COUNT << 1)
  30
  31 #define RLW_RUNNING_LEN_PLUS_BIT (((eword_t)1 << (RLW_RUNNING_BITS + 1)) - 1)
  32
  33 static int rlw_get_run_bit(const eword_t *word)
  34 {
  35         return *word & (eword_t)1;
  36 }
  37
  38 static inline void rlw_set_run_bit(eword_t *word, int b)
  39 {
  40         if (b) {
  41                 *word |= (eword_t)1;
  42         } else {
  43                 *word &= (eword_t)(~1);
  44         }
  45 }
  46
  47 static inline void rlw_xor_run_bit(eword_t *word)
  48 {
  49         if (*word & 1) {
  50                 *word &= (eword_t)(~1);
  51         } else {
  52                 *word |= (eword_t)1;
  53         }
  54 }
  55
  56 static inline void rlw_set_running_len(eword_t *word, eword_t l)
  57 {
  58         *word |= RLW_LARGEST_RUNNING_COUNT_SHIFT;
  59         *word &= (l << 1) | (~RLW_LARGEST_RUNNING_COUNT_SHIFT);
  60 }
  61
  62 static inline eword_t rlw_get_running_len(const eword_t *word)
  63 {
  64         return (*word >> 1) & RLW_LARGEST_RUNNING_COUNT;
  65 }
  66
  67 static inline eword_t rlw_get_literal_words(const eword_t *word)
  68 {
  69         return *word >> (1 + RLW_RUNNING_BITS);
  70 }
  71
  72 static inline void rlw_set_literal_words(eword_t *word, eword_t l)
  73 {
  74         *word |= ~RLW_RUNNING_LEN_PLUS_BIT;
  75         *word &= (l << (RLW_RUNNING_BITS + 1)) | RLW_RUNNING_LEN_PLUS_BIT;
  76 }
  77
  78 static inline eword_t rlw_size(const eword_t *self)
  79 {
  80         return rlw_get_running_len(self) + rlw_get_literal_words(self);
  81 }
  82
  83 struct rlw_iterator {
  84         const eword_t *buffer;
  85         size_t size;
  86         size_t pointer;
  87         size_t literal_word_start;
  88
  89         struct {
  90                 const eword_t *word;
  91                 int literal_words;
  92                 int running_len;
  93                 int literal_word_offset;
  94                 int running_bit;
  95         } rlw;
  96 };
  97
  98 void rlwit_init(struct rlw_iterator *it, struct ewah_bitmap *bitmap);
  99 void rlwit_discard_first_words(struct rlw_iterator *it, size_t x);
 100 size_t rlwit_discharge(
 101         struct rlw_iterator *it, struct ewah_bitmap *out, size_t max, int negate);
 102 void rlwit_discharge_empty(struct rlw_iterator *it, struct ewah_bitmap *out);
 103
 104 static inline size_t rlwit_word_size(struct rlw_iterator *it)
 105 {
 106         return it->rlw.running_len + it->rlw.literal_words;
 107 }
 108
 109 static inline size_t rlwit_literal_words(struct rlw_iterator *it)
 110 {
 111         return it->pointer - it->rlw.literal_words;
 112 }
 113
 114 #endif