1 /* Copyright (C) 1996,1997,1998,1999,2000,2003,2004 Free Software Foundation, Inc. 2 This file is part of the GNU C Library. 3 Written by Ulrich Drepper, <drepper@cygnus.com>. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 The GNU C Library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with the GNU C Library; if not, write to the Free 17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 18 02111-1307 USA. */ 19 20 /* Find index of weight. */ 21 auto inline int32_t 22 __attribute ((always_inline)) 23 findidx (const unsigned char **cpp) 24 { 25 int_fast32_t i = table[*(*cpp)++]; 26 const unsigned char *cp; 27 const unsigned char *usrc; 28 29 if (i >= 0) 30 /* This is an index into the weight table. Cool. */ 31 return i; 32 33 /* Oh well, more than one sequence starting with this byte. 34 Search for the correct one. */ 35 cp = &extra[-i]; 36 usrc = *cpp; 37 while (1) 38 { 39 size_t nhere; 40 41 /* The first thing is the index. */ 42 i = *((const int32_t *) cp); 43 cp += sizeof (int32_t); 44 45 /* Next is the length of the byte sequence. These are always 46 short byte sequences so there is no reason to call any 47 function (even if they are inlined). */ 48 nhere = *cp++; 49 50 if (i >= 0) 51 { 52 /* It is a single character. If it matches we found our 53 index. Note that at the end of each list there is an 54 entry of length zero which represents the single byte 55 sequence. The first (and here only) byte was tested 56 already. */ 57 size_t cnt; 58 59 for (cnt = 0; cnt < nhere; ++cnt) 60 if (cp[cnt] != usrc[cnt]) 61 break; 62 63 if (cnt == nhere) 64 { 65 /* Found it. */ 66 *cpp += nhere; 67 return i; 68 } 69 70 /* Up to the next entry. */ 71 cp += nhere; 72 if ((1 + nhere) % __alignof__ (int32_t) != 0) 73 cp += __alignof__ (int32_t) - (1 + nhere) % __alignof__ (int32_t); 74 } 75 else 76 { 77 /* This is a range of characters. First decide whether the 78 current byte sequence lies in the range. */ 79 size_t cnt; 80 size_t offset = 0; 81 82 for (cnt = 0; cnt < nhere; ++cnt) 83 if (cp[cnt] != usrc[cnt]) 84 break; 85 86 if (cnt != nhere) 87 { 88 if (cp[cnt] > usrc[cnt]) 89 { 90 /* Cannot be in this range. */ 91 cp += 2 * nhere; 92 if ((1 + 2 * nhere) % __alignof__ (int32_t) != 0) 93 cp += (__alignof__ (int32_t) 94 - (1 + 2 * nhere) % __alignof__ (int32_t)); 95 continue; 96 } 97 98 /* Test against the end of the range. */ 99 for (cnt = 0; cnt < nhere; ++cnt) 100 if (cp[nhere + cnt] != usrc[cnt]) 101 break; 102 103 if (cnt != nhere && cp[nhere + cnt] < usrc[cnt]) 104 { 105 /* Cannot be in this range. */ 106 cp += 2 * nhere; 107 if ((1 + 2 * nhere) % __alignof__ (int32_t) != 0) 108 cp += (__alignof__ (int32_t) 109 - (1 + 2 * nhere) % __alignof__ (int32_t)); 110 continue; 111 } 112 113 /* This range matches the next characters. Now find 114 the offset in the indirect table. */ 115 for (cnt = 0; cp[cnt] == usrc[cnt]; ++cnt); 116 117 do 118 { 119 offset <<= 8; 120 offset += usrc[cnt] - cp[cnt]; 121 } 122 while (++cnt < nhere); 123 } 124 125 *cpp += nhere; 126 return indirect[-i + offset]; 127 } 128 } 129 130 /* NOTREACHED */ 131 return 0x43219876; 132 } 133