[unix-history] / usr / src / sys / ufs / ffs / ffs_tables.c

/*
* Copyright (c) 1982, 1986 Regents of the University of California.
* All rights reserved.
*
* %sccs.include.redist.c%
*
*      @(#)ffs_tables.c        7.5 (Berkeley) %G%
*/

#include <sys/param.h>

/*
* Bit patterns for identifying fragments in the block map
* used as ((map & around) == inside)
*/
int around[9] = {
       0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff, 0x1ff, 0x3ff
};
int inside[9] = {
       0x0, 0x2, 0x6, 0xe, 0x1e, 0x3e, 0x7e, 0xfe, 0x1fe
};

/*
* Given a block map bit pattern, the frag tables tell whether a
* particular size fragment is available. 
*
* used as:
* if ((1 << (size - 1)) & fragtbl[fs->fs_frag][map] {
*      at least one fragment of the indicated size is available
* }
*
* These tables are used by the scanc instruction on the VAX to
* quickly find an appropriate fragment.
*/
u_char fragtbl124[256] = {
       0x00, 0x16, 0x16, 0x2a, 0x16, 0x16, 0x26, 0x4e,
       0x16, 0x16, 0x16, 0x3e, 0x2a, 0x3e, 0x4e, 0x8a,
       0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
       0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
       0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
       0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
       0x2a, 0x3e, 0x3e, 0x2a, 0x3e, 0x3e, 0x2e, 0x6e,
       0x3e, 0x3e, 0x3e, 0x3e, 0x2a, 0x3e, 0x6e, 0xaa,
       0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
       0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
       0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
       0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
       0x26, 0x36, 0x36, 0x2e, 0x36, 0x36, 0x26, 0x6e,
       0x36, 0x36, 0x36, 0x3e, 0x2e, 0x3e, 0x6e, 0xae,
       0x4e, 0x5e, 0x5e, 0x6e, 0x5e, 0x5e, 0x6e, 0x4e,
       0x5e, 0x5e, 0x5e, 0x7e, 0x6e, 0x7e, 0x4e, 0xce,
       0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
       0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
       0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
       0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
       0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
       0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
       0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e,
       0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 0xbe,
       0x2a, 0x3e, 0x3e, 0x2a, 0x3e, 0x3e, 0x2e, 0x6e,
       0x3e, 0x3e, 0x3e, 0x3e, 0x2a, 0x3e, 0x6e, 0xaa,
       0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e,
       0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 0xbe,
       0x4e, 0x5e, 0x5e, 0x6e, 0x5e, 0x5e, 0x6e, 0x4e,
       0x5e, 0x5e, 0x5e, 0x7e, 0x6e, 0x7e, 0x4e, 0xce,
       0x8a, 0x9e, 0x9e, 0xaa, 0x9e, 0x9e, 0xae, 0xce,
       0x9e, 0x9e, 0x9e, 0xbe, 0xaa, 0xbe, 0xce, 0x8a,
};

u_char fragtbl8[256] = {
       0x00, 0x01, 0x01, 0x02, 0x01, 0x01, 0x02, 0x04,
       0x01, 0x01, 0x01, 0x03, 0x02, 0x03, 0x04, 0x08,
       0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
       0x02, 0x03, 0x03, 0x02, 0x04, 0x05, 0x08, 0x10,
       0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
       0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
       0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06,
       0x04, 0x05, 0x05, 0x06, 0x08, 0x09, 0x10, 0x20,
       0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
       0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
       0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
       0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11,
       0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06,
       0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0a,
       0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04,
       0x08, 0x09, 0x09, 0x0a, 0x10, 0x11, 0x20, 0x40,
       0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
       0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
       0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
       0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11,
       0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
       0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
       0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07,
       0x05, 0x05, 0x05, 0x07, 0x09, 0x09, 0x11, 0x21,
       0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06,
       0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0a,
       0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07,
       0x02, 0x03, 0x03, 0x02, 0x06, 0x07, 0x0a, 0x12,
       0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04,
       0x05, 0x05, 0x05, 0x07, 0x06, 0x07, 0x04, 0x0c,
       0x08, 0x09, 0x09, 0x0a, 0x09, 0x09, 0x0a, 0x0c,
       0x10, 0x11, 0x11, 0x12, 0x20, 0x21, 0x40, 0x80,
};

/*
* The actual fragtbl array.
*/
u_char *fragtbl[MAXFRAG + 1] = {
       0, fragtbl124, fragtbl124, 0, fragtbl124, 0, 0, 0, fragtbl8,
};