xref: /csrg-svn/sys/ufs/ffs/ffs_tables.c (revision 29122)
123414Smckusick /*
2*29122Smckusick  * Copyright (c) 1982, 1986 Regents of the University of California.
323414Smckusick  * All rights reserved.  The Berkeley software License Agreement
423414Smckusick  * specifies the terms and conditions for redistribution.
523414Smckusick  *
6*29122Smckusick  *	@(#)ffs_tables.c	7.1 (Berkeley) 06/05/86
723414Smckusick  */
84462Smckusick 
917102Sbloom #include "param.h"
104462Smckusick 
114462Smckusick /*
1212757Ssam  * Bit patterns for identifying fragments in the block map
134462Smckusick  * used as ((map & around) == inside)
144462Smckusick  */
154462Smckusick int around[9] = {
164462Smckusick 	0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff, 0x1ff, 0x3ff
174462Smckusick };
184462Smckusick int inside[9] = {
194462Smckusick 	0x0, 0x2, 0x6, 0xe, 0x1e, 0x3e, 0x7e, 0xfe, 0x1fe
204462Smckusick };
214462Smckusick 
224462Smckusick /*
2312757Ssam  * Given a block map bit pattern, the frag tables tell whether a
244462Smckusick  * particular size fragment is available.
255323Smckusic  *
264462Smckusick  * used as:
275323Smckusic  * if ((1 << (size - 1)) & fragtbl[fs->fs_frag][map] {
284462Smckusick  *	at least one fragment of the indicated size is available
294462Smckusick  * }
305323Smckusic  *
315323Smckusic  * These tables are used by the scanc instruction on the VAX to
324462Smckusick  * quickly find an appropriate fragment.
334462Smckusick  */
3412757Ssam u_char fragtbl124[256] = {
356292Smckusick 	0x00, 0x16, 0x16, 0x2a, 0x16, 0x16, 0x26, 0x4e,
366292Smckusick 	0x16, 0x16, 0x16, 0x3e, 0x2a, 0x3e, 0x4e, 0x8a,
376292Smckusick 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
386292Smckusick 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
396292Smckusick 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
406292Smckusick 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
416292Smckusick 	0x2a, 0x3e, 0x3e, 0x2a, 0x3e, 0x3e, 0x2e, 0x6e,
426292Smckusick 	0x3e, 0x3e, 0x3e, 0x3e, 0x2a, 0x3e, 0x6e, 0xaa,
436292Smckusick 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
446292Smckusick 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
456292Smckusick 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
466292Smckusick 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
476292Smckusick 	0x26, 0x36, 0x36, 0x2e, 0x36, 0x36, 0x26, 0x6e,
486292Smckusick 	0x36, 0x36, 0x36, 0x3e, 0x2e, 0x3e, 0x6e, 0xae,
496292Smckusick 	0x4e, 0x5e, 0x5e, 0x6e, 0x5e, 0x5e, 0x6e, 0x4e,
506292Smckusick 	0x5e, 0x5e, 0x5e, 0x7e, 0x6e, 0x7e, 0x4e, 0xce,
516292Smckusick 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
526292Smckusick 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
536292Smckusick 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
546292Smckusick 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
556292Smckusick 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
566292Smckusick 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
576292Smckusick 	0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e,
586292Smckusick 	0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 0xbe,
596292Smckusick 	0x2a, 0x3e, 0x3e, 0x2a, 0x3e, 0x3e, 0x2e, 0x6e,
606292Smckusick 	0x3e, 0x3e, 0x3e, 0x3e, 0x2a, 0x3e, 0x6e, 0xaa,
616292Smckusick 	0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e,
626292Smckusick 	0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 0xbe,
636292Smckusick 	0x4e, 0x5e, 0x5e, 0x6e, 0x5e, 0x5e, 0x6e, 0x4e,
646292Smckusick 	0x5e, 0x5e, 0x5e, 0x7e, 0x6e, 0x7e, 0x4e, 0xce,
656292Smckusick 	0x8a, 0x9e, 0x9e, 0xaa, 0x9e, 0x9e, 0xae, 0xce,
666292Smckusick 	0x9e, 0x9e, 0x9e, 0xbe, 0xaa, 0xbe, 0xce, 0x8a,
675323Smckusic };
685323Smckusic 
6912757Ssam u_char fragtbl8[256] = {
704462Smckusick 	0x00, 0x01, 0x01, 0x02, 0x01, 0x01, 0x02, 0x04,
714462Smckusick 	0x01, 0x01, 0x01, 0x03, 0x02, 0x03, 0x04, 0x08,
724462Smckusick 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
734462Smckusick 	0x02, 0x03, 0x03, 0x02, 0x04, 0x05, 0x08, 0x10,
744462Smckusick 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
754462Smckusick 	0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
764462Smckusick 	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06,
774462Smckusick 	0x04, 0x05, 0x05, 0x06, 0x08, 0x09, 0x10, 0x20,
784462Smckusick 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
794462Smckusick 	0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
804462Smckusick 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
814462Smckusick 	0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11,
824462Smckusick 	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06,
834462Smckusick 	0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0a,
844462Smckusick 	0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04,
854462Smckusick 	0x08, 0x09, 0x09, 0x0a, 0x10, 0x11, 0x20, 0x40,
864462Smckusick 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
874462Smckusick 	0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
884462Smckusick 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
894462Smckusick 	0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11,
904462Smckusick 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
914462Smckusick 	0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
924462Smckusick 	0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07,
934462Smckusick 	0x05, 0x05, 0x05, 0x07, 0x09, 0x09, 0x11, 0x21,
944462Smckusick 	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06,
954462Smckusick 	0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0a,
964462Smckusick 	0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07,
974462Smckusick 	0x02, 0x03, 0x03, 0x02, 0x06, 0x07, 0x0a, 0x12,
984462Smckusick 	0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04,
994462Smckusick 	0x05, 0x05, 0x05, 0x07, 0x06, 0x07, 0x04, 0x0c,
1004462Smckusick 	0x08, 0x09, 0x09, 0x0a, 0x09, 0x09, 0x0a, 0x0c,
1014462Smckusick 	0x10, 0x11, 0x11, 0x12, 0x20, 0x21, 0x40, 0x80,
1024462Smckusick };
1035323Smckusic 
1045323Smckusic /*
10512757Ssam  * The actual fragtbl array.
1065323Smckusic  */
10712757Ssam u_char *fragtbl[MAXFRAG + 1] = {
1086292Smckusick 	0, fragtbl124, fragtbl124, 0, fragtbl124, 0, 0, 0, fragtbl8,
1095323Smckusic };
110