| 1 | /* Generate transitive closure of a matrix, |
| 2 | Copyright (C) 1984, 1989, 2000 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of Bison, the GNU Compiler Compiler. |
| 5 | |
| 6 | Bison is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 2, or (at your option) |
| 9 | any later version. |
| 10 | |
| 11 | Bison is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with Bison; see the file COPYING. If not, write to |
| 18 | the Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| 19 | Boston, MA 02111-1307, USA. */ |
| 20 | |
| 21 | |
| 22 | #include "system.h" |
| 23 | #include "warshall.h" |
| 24 | |
| 25 | /* Given n by n matrix of bits R, modify its contents to be the |
| 26 | transive closure of what was given. */ |
| 27 | |
| 28 | static void |
| 29 | TC (unsigned *R, int n) |
| 30 | { |
| 31 | int rowsize; |
| 32 | unsigned mask; |
| 33 | unsigned *rowj; |
| 34 | unsigned *rp; |
| 35 | unsigned *rend; |
| 36 | unsigned *ccol; |
| 37 | |
| 38 | unsigned *relend; |
| 39 | unsigned *cword; |
| 40 | unsigned *rowi; |
| 41 | |
| 42 | rowsize = WORDSIZE(n) * sizeof(unsigned); |
| 43 | relend = (unsigned *) ((char *) R + (n * rowsize)); |
| 44 | |
| 45 | cword = R; |
| 46 | mask = 1; |
| 47 | rowi = R; |
| 48 | while (rowi < relend) |
| 49 | { |
| 50 | ccol = cword; |
| 51 | rowj = R; |
| 52 | |
| 53 | while (rowj < relend) |
| 54 | { |
| 55 | if (*ccol & mask) |
| 56 | { |
| 57 | rp = rowi; |
| 58 | rend = (unsigned *) ((char *) rowj + rowsize); |
| 59 | |
| 60 | while (rowj < rend) |
| 61 | *rowj++ |= *rp++; |
| 62 | } |
| 63 | else |
| 64 | { |
| 65 | rowj = (unsigned *) ((char *) rowj + rowsize); |
| 66 | } |
| 67 | |
| 68 | ccol = (unsigned *) ((char *) ccol + rowsize); |
| 69 | } |
| 70 | |
| 71 | mask <<= 1; |
| 72 | if (mask == 0) |
| 73 | { |
| 74 | mask = 1; |
| 75 | cword++; |
| 76 | } |
| 77 | |
| 78 | rowi = (unsigned *) ((char *) rowi + rowsize); |
| 79 | } |
| 80 | } |
| 81 | |
| 82 | |
| 83 | /* Reflexive Transitive Closure. Same as TC |
| 84 | and then set all the bits on the diagonal of R. */ |
| 85 | |
| 86 | void |
| 87 | RTC (unsigned *R, int n) |
| 88 | { |
| 89 | int rowsize; |
| 90 | unsigned mask; |
| 91 | unsigned *rp; |
| 92 | unsigned *relend; |
| 93 | |
| 94 | TC(R, n); |
| 95 | |
| 96 | rowsize = WORDSIZE(n) * sizeof(unsigned); |
| 97 | relend = (unsigned *) ((char *) R + n*rowsize); |
| 98 | |
| 99 | mask = 1; |
| 100 | rp = R; |
| 101 | while (rp < relend) |
| 102 | { |
| 103 | *rp |= mask; |
| 104 | |
| 105 | mask <<= 1; |
| 106 | if (mask == 0) |
| 107 | { |
| 108 | mask = 1; |
| 109 | rp++; |
| 110 | } |
| 111 | |
| 112 | rp = (unsigned *) ((char *) rp + rowsize); |
| 113 | } |
| 114 | } |