summaryrefslogtreecommitdiffstats
path: root/SD-VBS/benchmarks/stitch/src/c
diff options
context:
space:
mode:
Diffstat (limited to 'SD-VBS/benchmarks/stitch/src/c')
0 files changed, 0 insertions, 0 deletions
generated by cgit v1.2.2 (git 2.25.0) at 2026-11-07 23:42:07 -0500
#n76'>76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 
/*

  FILE NAME:   bits.c

  TITLE:       Package for work with bits

  DESCRIPTION: This file implements functions of the package for work
      with bit strings.  A bit is given by address (start address) of
      byte from which counting bits starts and its displacement which
      is any non negative number of bit from the start address.  The
      most significant bit of the start address byte has number 0.
      The bit string is given by its first bit and its length in
      bits.

*/

#include "bits.h"

/* This function determines that given bit string contains only zero
   bits.  The function retruns TRUE if all bits of given bit string
   are zero or `bit_length' <= 0.  Value of `bit_displacement' must be
   non-negative and can be greater than CHAR_BIT. */

int
ammunition_is_zero_bit_string ( const void *start_byte, int bit_displacement,
                                int bit_length )
{
  const unsigned char *current_byte = ( unsigned const char * )start_byte;

  if ( bit_length <= 0 )
    return 1 /* TRUE */;
  current_byte += bit_displacement / CHAR_BIT;
  bit_displacement %= CHAR_BIT;
  if ( bit_length < CHAR_BIT - bit_displacement )
    return ( ( ( *current_byte << bit_displacement )
               & ( UCHAR_MAX << ( CHAR_BIT - bit_length ) ) )
             & UCHAR_MAX ) == 0;
  else
    if ( bit_displacement != 0 ) {
      if ( ( ( *current_byte << bit_displacement ) & UCHAR_MAX ) != 0 )
        return 0 /* FALSE */;
      current_byte += 1;
      bit_length -= CHAR_BIT - bit_displacement;
    }
  _Pragma( "loopbound min 0 max 7" )
  while ( bit_length >= CHAR_BIT ) {
    if ( *current_byte != 0 )
      return 0 /* FALSE */;
    current_byte++;
    bit_length -= CHAR_BIT;
  }
  if ( bit_length > 0 && ( *current_byte >> ( CHAR_BIT - bit_length ) ) != 0 )
    return 0 /* FALSE */;
  return 1 /* TRUE */;
}

/* This function sets up new value of all bits of given bit string.
   This function is analog of standard C function `memset'.  Value of
   `bit_displacement' must be non-negative and can be greater than
   CHAR_BIT. */

void
ammunition_bit_string_set ( void *start_byte, int bit_displacement, int bit,
                            int bit_length )
{
  unsigned char *current_byte = ( unsigned char * )start_byte;
  unsigned char filling_byte;
  int mask;

  if ( bit_length <= 0 )
    return ;
  bit = bit != 0; /* 1 or 0 */
  filling_byte = ( bit ? UCHAR_MAX : 0 );
  current_byte += bit_displacement / CHAR_BIT;
  bit_displacement %= CHAR_BIT;
  if ( bit_displacement != 0 ) {
    mask = UCHAR_MAX << ( CHAR_BIT - bit_displacement );
    if ( bit_length < CHAR_BIT - bit_displacement )
      mask |= UCHAR_MAX >> ( bit_displacement + bit_length );
    *current_byte = ( *current_byte & mask ) | ( filling_byte & ~mask );
    current_byte += 1;
    bit_length -= CHAR_BIT - bit_displacement;
  }
  _Pragma( "loopbound min 0 max 8" )
  while ( bit_length >= CHAR_BIT ) {
    *current_byte = filling_byte;
    current_byte++;
    bit_length -= CHAR_BIT;
  }
  if ( bit_length > 0 )
    *current_byte
      = ( *current_byte & ~( UCHAR_MAX << ( CHAR_BIT - bit_length ) ) )
        | ( filling_byte & ( UCHAR_MAX << ( CHAR_BIT - bit_length ) ) );
}

/* This function copys a bit string to another bit string.  This
   function is analog of standard C function `memcpy'.  Values of
   `to_bit_displacement' and `from_bit_displacement' must be
   non-negative and can be greater than CHAR_BIT.  The bit string must
   be non-overlapped. */

void
ammunition_bit_string_copy ( void *to, int to_bit_displacement,
                             const void *from, int from_bit_displacement,
                             int bit_length )
{
  unsigned char *current_to_byte = ( unsigned char * )to;
  const unsigned char *current_from_byte = ( unsigned const char * )from;
  int byte;
  int mask;

  if ( bit_length <= 0 )
    return ;
  current_to_byte += to_bit_displacement / CHAR_BIT;
  to_bit_displacement %= CHAR_BIT;
  current_from_byte += from_bit_displacement / CHAR_BIT;
  from_bit_displacement %= CHAR_BIT;
  _Pragma( "loopbound min 1 max 8" )
  while ( 1 ) {
    byte = ( ( ( *current_from_byte << from_bit_displacement ) & UCHAR_MAX )
             | ( from_bit_displacement != 0
                 && bit_length > ( CHAR_BIT - from_bit_displacement )
                 ? current_from_byte [1] >> ( CHAR_BIT - from_bit_displacement )
                 : 0 ) );
    if ( bit_length <= CHAR_BIT )
      break;
    /* Shift is correct when to_bit_displacement == 0 because its
       value is less than word bit size. */
    *current_to_byte
      = ( *current_to_byte
          & ( UCHAR_MAX << ( CHAR_BIT - to_bit_displacement ) ) )
        | ( byte >> to_bit_displacement );
    if ( to_bit_displacement != 0 )
      current_to_byte [1]
        = ( current_to_byte [1] & ( UCHAR_MAX >> to_bit_displacement ) )
          | ( byte << ( CHAR_BIT - to_bit_displacement ) );
    bit_length -= CHAR_BIT;
    current_from_byte++;
    current_to_byte++;
  }
  /* Shift is correct when to_bit_displacement == 0 because its
    value is less than word bit size. */
  mask = ( ( UCHAR_MAX << ( CHAR_BIT - to_bit_displacement ) )
           | ( UCHAR_MAX >> ( to_bit_displacement + bit_length ) ) );
  *current_to_byte
    = ( *current_to_byte & mask ) | ( ( byte >> to_bit_displacement ) & ~mask );
  bit_length -= CHAR_BIT - to_bit_displacement;
  if ( bit_length > 0 )
    current_to_byte [1]
      = ( current_to_byte [1] & ( UCHAR_MAX >> bit_length ) )
        | ( ( byte << ( CHAR_BIT - to_bit_displacement ) )
            & ( UCHAR_MAX << ( CHAR_BIT - bit_length ) ) );
}

/* This function copys a bit string to another bit string.  Copying
   starts with the last bits of the bit strings.  This function is
   used by function `bit_string_move'.  Values of
   `to_bit_displacement' and `from_bit_displacement' must be
   non-negative and can be greater than CHAR_BIT.  The bit string must
   be non-overlapped. */

void ammunition_reverse_bit_string_copy ( void *to, int to_bit_displacement,
    const void *from, int from_bit_displacement,
    int bit_length )
{
  unsigned char *current_to_byte = ( unsigned char * )to;
  const unsigned char *current_from_byte = ( unsigned const char * )from;
  int byte;
  int mask;

  if ( bit_length <= 0 )
    return ;
  to_bit_displacement += bit_length - 1;
  current_to_byte += to_bit_displacement / CHAR_BIT; /* last byte */
  to_bit_displacement %= CHAR_BIT; /* last bit */
  from_bit_displacement += bit_length - 1;
  current_from_byte += from_bit_displacement / CHAR_BIT; /* last byte */
  from_bit_displacement %= CHAR_BIT; /* last bit */
  _Pragma( "loopbound min 1 max 8" )
  while ( 1 ) {
    /* Shift is correct when to_bit_displacement == 0 because its
       value is less than word bit size. */
    byte = ( ( *current_from_byte >> ( CHAR_BIT - 1 - from_bit_displacement ) )
             | ( ( from_bit_displacement != CHAR_BIT - 1
                   && bit_length > from_bit_displacement + 1
                   ? current_from_byte [ -1 ] << ( from_bit_displacement + 1 ) 
                     : 0 )
                 & UCHAR_MAX ) );
    if ( bit_length <= CHAR_BIT )
      break;
    /* Shift is correct when to_bit_displacement == 0 because its
       value is less than word bit size. */
    *current_to_byte
      = ( *current_to_byte & ( UCHAR_MAX >> ( to_bit_displacement + 1 ) ) )
        | ( byte << ( CHAR_BIT - 1 - to_bit_displacement ) );
    if ( to_bit_displacement != CHAR_BIT - 1 )
      current_to_byte [-1]
        = ( current_to_byte [-1]
            & ( UCHAR_MAX << ( CHAR_BIT - 1 - to_bit_displacement ) ) )
          | ( byte >> ( to_bit_displacement + 1 ) );
    bit_length -= CHAR_BIT;
    current_from_byte--;
    current_to_byte--;
  }
  /* Shift is correct when to_bit_displacement == 0 because its
    value is less than word bit size. */
  mask = ( ( UCHAR_MAX >> ( to_bit_displacement + 1 ) ) |
           ( UCHAR_MAX << ( CHAR_BIT - 1 - to_bit_displacement
                            + bit_length ) ) );
  *current_to_byte
    = ( *current_to_byte & mask )
      | ( ( byte << ( CHAR_BIT - 1 - to_bit_displacement ) ) & ~mask );
  bit_length -= to_bit_displacement + 1;
  if ( bit_length > 0 )
    current_to_byte [-1]
      = ( current_to_byte [-1] & ( UCHAR_MAX << bit_length ) )
        | ( byte >> ( to_bit_displacement + 1 )
            & ( UCHAR_MAX >> ( CHAR_BIT - bit_length ) ) );
}

/* This function copys a bit string to another bit string with the aid
   of functions `bit_string_copy' and `reverse_bit_string_copy'.  This
   function is analog of standard C function `memmove'.  Values of
   `to_bit_displacement' and `from_bit_displacement' must be
   non-negative and can be greater than CHAR_BIT.  The bit string can
   be overlapped. */

void
ammunition_bit_string_move ( void *to, int to_bit_displacement,
                             const void *from, int from_bit_displacement,
                             int bit_length )
{
  unsigned char *current_to_byte = ( unsigned char * )to;
  const unsigned char *current_from_byte = ( unsigned const char * )from;

  if ( bit_length <= 0 )
    return ;
  current_to_byte += to_bit_displacement / CHAR_BIT;
  to_bit_displacement %= CHAR_BIT;
  current_from_byte += from_bit_displacement / CHAR_BIT;
  from_bit_displacement %= CHAR_BIT;
  if ( current_from_byte > current_to_byte
       || ( current_from_byte == current_to_byte
            && from_bit_displacement > to_bit_displacement ) )
    ammunition_bit_string_copy ( current_to_byte, to_bit_displacement,
                                 current_from_byte, from_bit_displacement,
                                 bit_length );
  else
    ammunition_reverse_bit_string_copy ( current_to_byte, to_bit_displacement,
                                         current_from_byte,
                                         from_bit_displacement, bit_length );
}

/* This function compares bit strings.  This function is analog of
   standard C function `memcmp'.  The function returns 0 if the bit
   strings are equal, 1 if the first bit string is greater than the
   second, -1 if the first bit string is less than the first.  Values
   of `bit_displacement1' and `bit_displacement2' must be non-negative
   and can be greater than CHAR_BIT. */

int
ammunition_bit_string_comparison ( const void *str1, int bit_displacement1,
                                   const void *str2, int bit_displacement2,
                                   int bit_length )
{
  const unsigned char *current_byte1 = ( unsigned const char * )str1;
  const unsigned char *current_byte2 = ( unsigned const char * )str2;
  int byte1;
  int byte2;
  int mask;

  if ( bit_length <= 0 )
    return 0;
  current_byte1 += bit_displacement1 / CHAR_BIT;
  bit_displacement1 %= CHAR_BIT;
  current_byte2 += bit_displacement2 / CHAR_BIT;
  bit_displacement2 %= CHAR_BIT;
  _Pragma( "loopbound min 1 max 284" )
  while ( 1 ) {
    byte1 = ( ( ( *current_byte1 << bit_displacement1 ) & UCHAR_MAX )
              | ( bit_displacement1 != 0
                  /* Shift is correct when to_bit_displacement == 0
                     because its value is less than word bit size. */
                  && bit_length > CHAR_BIT - bit_displacement1
                  ? current_byte1 [1] >> ( CHAR_BIT - bit_displacement1 )
                  : 0 ) );
    byte2 = ( ( ( *current_byte2 << bit_displacement2 ) & UCHAR_MAX )
              | ( bit_displacement2 != 0
                  && bit_length > CHAR_BIT - bit_displacement2
                  ? current_byte2 [1] >> ( CHAR_BIT - bit_displacement2 )
                  : 0 ) );
    if ( bit_length <= CHAR_BIT )
      break;
    if ( byte1 > byte2 )
      return 1;
    else
      if ( byte1 < byte2 )
        return -1;
    bit_length -= CHAR_BIT;
    current_byte2++;
    current_byte1++;
  }
  /* Shift is correct when to_bit_displacement == 0 because its value
    is less than word bit size. */
  mask = UCHAR_MAX << ( CHAR_BIT - bit_length );
  if ( ( byte1 & mask ) > ( byte2 & mask ) )
    return 1;
  else
    if ( ( byte1 & mask ) < ( byte2 & mask ) )
      return -1;
    else
      return 0;
}
generated by cgit v1.2.2 (git 2.25.0) at 2026-11-07 23:42:08 -0500