| /* Copyright (C) 2000-2018 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 Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 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 |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <stdint.h> |
| |
| /* Tables indexed by a wide character are compressed through the use |
| of a multi-level lookup. The compression effect comes from blocks |
| that don't need particular data and from blocks that can share their |
| data. */ |
| |
| /* Bit tables are accessed by cutting wc in four blocks of bits: |
| - the high 32-q-p bits, |
| - the next q bits, |
| - the next p bits, |
| - the next 5 bits. |
| |
| +------------------+-----+-----+-----+ |
| wc = + 32-q-p-5 | q | p | 5 | |
| +------------------+-----+-----+-----+ |
| |
| p and q are variable. For 16-bit Unicode it is sufficient to |
| choose p and q such that q+p+5 <= 16. |
| |
| The table contains the following uint32_t words: |
| - q+p+5, |
| - s = upper exclusive bound for wc >> (q+p+5), |
| - p+5, |
| - 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. |
| */ |
| |
| static __inline int |
| __attribute ((always_inline)) |
| wctype_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 >> 5) & mask3; |
| uint32_t lookup3 = ((const uint32_t *)(table + lookup2))[index3]; |
| |
| return (lookup3 >> (wc & 0x1f)) & 1; |
| } |
| } |
| } |
| return 0; |
| } |
| |
| /* Byte tables are similar to bit tables, except that the addressing |
| unit is a single byte, and no 5 bits are used as a word index. */ |
| |
| static __inline int |
| __attribute ((always_inline)) |
| wcwidth_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; |
| uint8_t lookup3 = ((const uint8_t *)(table + lookup2))[index3]; |
| |
| return lookup3; |
| } |
| } |
| } |
| return 0xff; |
| } |
| |
| /* Mapping tables are similar to bit tables, except that the |
| addressing unit is a single signed 32-bit word, containing the |
| difference between the desired result and the argument, and no 5 |
| bits are used as a word index. */ |
| |
| static __inline uint32_t |
| __attribute ((always_inline)) |
| wctrans_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 wc + lookup3; |
| } |
| } |
| } |
| return wc; |
| } |