1 /* bag.c -- ARMulator support code: ARM6 Instruction Emulator.
2 Copyright (C) 1994 Advanced RISC Machines Ltd.
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
18 /********************************************************************/
20 /* Offers a data structure for storing and getting pairs of number. */
21 /* The numbers are stored together, put one can be looked up by */
22 /* quoting the other. If a new pair is entered and one of the */
23 /* numbers is a repeat of a previous pair, then the previos pair */
25 /********************************************************************/
29 #define HASH_TABLE_SIZE 256
30 #define hash(x) (((x)&0xff)^(((x)>>8)&0xff)^(((x)>>16)&0xff)^(((x)>>24)&0xff))
32 typedef struct hashentry
34 struct hashentry *next;
40 Hashentry *lookupbyfirst[HASH_TABLE_SIZE];
41 Hashentry *lookupbysecond[HASH_TABLE_SIZE];
44 addtolist (Hashentry ** add, long first, long second)
47 add = &((*add)->next);
48 /* Malloc will never fail? :o( */
49 (*add) = (Hashentry *) malloc (sizeof (Hashentry));
50 (*add)->next = (Hashentry *) 0;
51 (*add)->first = first;
52 (*add)->second = second;
56 killwholelist (Hashentry * p)
69 removefromlist (Hashentry ** p, long first, long second)
75 if ((*p)->first == first)
87 BAG_putpair (long first, long second)
91 if (BAG_getfirst (&junk, second) != NO_SUCH_PAIR)
92 BAG_killpair_bysecond (second);
93 addtolist (&lookupbyfirst[hash (first)], first, second);
94 addtolist (&lookupbysecond[hash (second)], first, second);
98 BAG_getfirst (long *first, long second)
102 look = lookupbysecond[hash (second)];
104 if (look->second == second)
106 *first = look->first;
113 BAG_getsecond (long first, long *second)
117 look = lookupbyfirst[hash (first)];
120 if (look->first == first)
122 *second = look->second;
131 BAG_killpair_byfirst (long first)
135 if (BAG_getsecond (first, &second) == NO_SUCH_PAIR)
137 removefromlist (&lookupbyfirst[hash (first)], first, second);
138 removefromlist (&lookupbysecond[hash (second)], first, second);
143 BAG_killpair_bysecond (long second)
147 if (BAG_getfirst (&first, second) == NO_SUCH_PAIR)
149 removefromlist (&lookupbyfirst[hash (first)], first, second);
150 removefromlist (&lookupbysecond[hash (second)], first, second);
159 for (i = 0; i < 256; i++)
161 killwholelist (lookupbyfirst[i]);
162 killwholelist (lookupbysecond[i]);
163 lookupbyfirst[i] = lookupbysecond[i] = (Hashentry *) 0;