1/* CGEN generic opcode support.
2
3   Copyright 2002, 2005
4   Free Software Foundation, Inc.
5
6   This file is part of the GNU Binutils and GDB, the GNU debugger.
7
8   This program is free software; you can redistribute it and/or modify
9   it under the terms of the GNU General Public License as published by
10   the Free Software Foundation; either version 2, or (at your option)
11   any later version.
12
13   This program is distributed in the hope that it will be useful,
14   but WITHOUT ANY WARRANTY; without even the implied warranty of
15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16   GNU General Public License for more details.
17
18   You should have received a copy of the GNU General Public License along
19   with this program; if not, write to the Free Software Foundation, Inc.,
20   51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
21
22/* Functions for manipulating CGEN_BITSET.  */
23
24#include "libiberty.h"
25#include "opcode/cgen-bitset.h"
26#include <string.h>
27
28/* Create a bit mask.  */
29CGEN_BITSET *
30cgen_bitset_create (unsigned bit_count)
31{
32  CGEN_BITSET * mask = xmalloc (sizeof (* mask));
33  cgen_bitset_init (mask, bit_count);
34  return mask;
35}
36
37/* Initialize an existing bit mask.  */
38
39void
40cgen_bitset_init (CGEN_BITSET * mask, unsigned bit_count)
41{
42  if (! mask)
43    return;
44  mask->length = (bit_count / 8) + 1;
45  mask->bits = xmalloc (mask->length);
46  cgen_bitset_clear (mask);
47}
48
49/* Clear the bits of a bit mask.  */
50
51void
52cgen_bitset_clear (CGEN_BITSET * mask)
53{
54  unsigned i;
55
56  if (! mask)
57    return;
58
59  for (i = 0; i < mask->length; ++i)
60    mask->bits[i] = 0;
61}
62
63/* Add a bit to a bit mask.  */
64
65void
66cgen_bitset_add (CGEN_BITSET * mask, unsigned bit_num)
67{
68  int byte_ix, bit_ix;
69  int bit_mask;
70
71  if (! mask)
72    return;
73  byte_ix = bit_num / 8;
74  bit_ix = bit_num % 8;
75  bit_mask = 1 << (7 - bit_ix);
76  mask->bits[byte_ix] |= bit_mask;
77}
78
79/* Set a bit mask.  */
80
81void
82cgen_bitset_set (CGEN_BITSET * mask, unsigned bit_num)
83{
84  if (! mask)
85    return;
86  cgen_bitset_clear (mask);
87  cgen_bitset_add (mask, bit_num);
88}
89
90/* Test for a bit in a bit mask.
91   Returns 1 if the bit is found  */
92
93int
94cgen_bitset_contains (CGEN_BITSET * mask, unsigned bit_num)
95{
96  int byte_ix, bit_ix;
97  int bit_mask;
98
99  if (! mask)
100    return 1; /* No bit restrictions.  */
101
102  byte_ix = bit_num / 8;
103  bit_ix = 7 - (bit_num % 8);
104  bit_mask = 1 << bit_ix;
105  return (mask->bits[byte_ix] & bit_mask) >> bit_ix;
106}
107
108/* Compare two bit masks for equality.
109   Returns 0 if they are equal.  */
110
111int
112cgen_bitset_compare (CGEN_BITSET * mask1, CGEN_BITSET * mask2)
113{
114  if (mask1 == mask2)
115    return 0;
116  if (! mask1 || ! mask2)
117    return 1;
118  if (mask1->length != mask2->length)
119    return 1;
120  return memcmp (mask1->bits, mask2->bits, mask1->length);
121}
122
123/* Test two bit masks for common bits.
124   Returns 1 if a common bit is found.  */
125
126int
127cgen_bitset_intersect_p (CGEN_BITSET * mask1, CGEN_BITSET * mask2)
128{
129  unsigned i, limit;
130
131  if (mask1 == mask2)
132    return 1;
133  if (! mask1 || ! mask2)
134    return 0;
135  limit = mask1->length < mask2->length ? mask1->length : mask2->length;
136
137  for (i = 0; i < limit; ++i)
138    if ((mask1->bits[i] & mask2->bits[i]))
139      return 1;
140
141  return 0;
142}
143
144/* Make a copy of a bit mask.  */
145
146CGEN_BITSET *
147cgen_bitset_copy (CGEN_BITSET * mask)
148{
149  CGEN_BITSET* newmask;
150
151  if (! mask)
152    return NULL;
153  newmask = cgen_bitset_create ((mask->length * 8) - 1);
154  memcpy (newmask->bits, mask->bits, mask->length);
155  return newmask;
156}
157
158/* Combine two bit masks.  */
159
160void
161cgen_bitset_union (CGEN_BITSET * mask1, CGEN_BITSET * mask2,
162		   CGEN_BITSET * result)
163{
164  unsigned i;
165
166  if (! mask1 || ! mask2 || ! result
167      || mask1->length != mask2->length
168      || mask1->length != result->length)
169    return;
170
171  for (i = 0; i < result->length; ++i)
172    result->bits[i] = mask1->bits[i] | mask2->bits[i];
173}
174