/* Copyright (C) 2000 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Bruno Haible <haible@clisp.cons.org>, 2000. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* Word tables are accessed by cutting wc in three blocks of bits: - the high 32-q-p bits, - the next q bits, - the next p bits. +------------------+-----+-----+ wc = + 32-q-p | q | p | +------------------+-----+-----+ p and q are variable. For 16-bit Unicode it is sufficient to choose p and q such that q+p <= 16. The table contains the following uint32_t words: - q+p, - s = upper exclusive bound for wc >> (q+p), - p, - 2^q-1, - 2^p-1, - 1st-level table: s offsets, pointing into the 2nd-level table, - 2nd-level table: k*2^q offsets, pointing into the 3rd-level table, - 3rd-level table: j*2^p words, each containing 32 bits of data. */ #include <stdint.h> /* Lookup in a table of int32_t, with default value 0. */ static inline int32_t collidx_table_lookup (const char *table, uint32_t wc) { uint32_t shift1 = ((const uint32_t *) table)[0]; uint32_t index1 = wc >> shift1; uint32_t bound = ((const uint32_t *) table)[1]; if (index1 < bound) { uint32_t lookup1 = ((const uint32_t *) table)[5 + index1]; if (lookup1 != 0) { uint32_t shift2 = ((const uint32_t *) table)[2]; uint32_t mask2 = ((const uint32_t *) table)[3]; uint32_t index2 = (wc >> shift2) & mask2; uint32_t lookup2 = ((const uint32_t *)(table + lookup1))[index2]; if (lookup2 != 0) { uint32_t mask3 = ((const uint32_t *) table)[4]; uint32_t index3 = wc & mask3; int32_t lookup3 = ((const int32_t *)(table + lookup2))[index3]; return lookup3; } } } return 0; } /* Lookup in a table of uint32_t, with default value 0xffffffff. */ static inline uint32_t collseq_table_lookup (const char *table, uint32_t wc) { uint32_t shift1 = ((const uint32_t *) table)[0]; uint32_t index1 = wc >> shift1; uint32_t bound = ((const uint32_t *) table)[1]; if (index1 < bound) { uint32_t lookup1 = ((const uint32_t *) table)[5 + index1]; if (lookup1 != 0) { uint32_t shift2 = ((const uint32_t *) table)[2]; uint32_t mask2 = ((const uint32_t *) table)[3]; uint32_t index2 = (wc >> shift2) & mask2; uint32_t lookup2 = ((const uint32_t *)(table + lookup1))[index2]; if (lookup2 != 0) { uint32_t mask3 = ((const uint32_t *) table)[4]; uint32_t index3 = wc & mask3; uint32_t lookup3 = ((const uint32_t *)(table + lookup2))[index3]; return lookup3; } } } return ~((uint32_t) 0); }