1/* CGEN generic opcode support.
2   Copyright 2002, 2005, 2007
3   Free Software Foundation, Inc.
4
5   This file is part of libopcodes.
6
7   This library is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 3, or (at your option)
10   any later version.
11
12   It is distributed in the hope that it will be useful, but WITHOUT
13   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
15   License for more details.
16
17   You should have received a copy of the GNU General Public License along
18   with this program; if not, write to the Free Software Foundation, Inc.,
19   51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
20
21/* Functions for manipulating CGEN_BITSET.  */
22
23#include "libiberty.h"
24#include "opcode/cgen-bitset.h"
25#include <string.h>
26
27/* Create a bit mask.  */
28CGEN_BITSET *
29cgen_bitset_create (unsigned bit_count)
30{
31  CGEN_BITSET * mask = xmalloc (sizeof (* mask));
32  cgen_bitset_init (mask, bit_count);
33  return mask;
34}
35
36/* Initialize an existing bit mask.  */
37
38void
39cgen_bitset_init (CGEN_BITSET * mask, unsigned bit_count)
40{
41  if (! mask)
42    return;
43  mask->length = (bit_count / 8) + 1;
44  mask->bits = xmalloc (mask->length);
45  cgen_bitset_clear (mask);
46}
47
48/* Clear the bits of a bit mask.  */
49
50void
51cgen_bitset_clear (CGEN_BITSET * mask)
52{
53  unsigned i;
54
55  if (! mask)
56    return;
57
58  for (i = 0; i < mask->length; ++i)
59    mask->bits[i] = 0;
60}
61
62/* Add a bit to a bit mask.  */
63
64void
65cgen_bitset_add (CGEN_BITSET * mask, unsigned bit_num)
66{
67  int byte_ix, bit_ix;
68  int bit_mask;
69
70  if (! mask)
71    return;
72  byte_ix = bit_num / 8;
73  bit_ix = bit_num % 8;
74  bit_mask = 1 << (7 - bit_ix);
75  mask->bits[byte_ix] |= bit_mask;
76}
77
78/* Set a bit mask.  */
79
80void
81cgen_bitset_set (CGEN_BITSET * mask, unsigned bit_num)
82{
83  if (! mask)
84    return;
85  cgen_bitset_clear (mask);
86  cgen_bitset_add (mask, bit_num);
87}
88
89/* Test for a bit in a bit mask.
90   Returns 1 if the bit is found  */
91
92int
93cgen_bitset_contains (CGEN_BITSET * mask, unsigned bit_num)
94{
95  int byte_ix, bit_ix;
96  int bit_mask;
97
98  if (! mask)
99    return 1; /* No bit restrictions.  */
100
101  byte_ix = bit_num / 8;
102  bit_ix = 7 - (bit_num % 8);
103  bit_mask = 1 << bit_ix;
104  return (mask->bits[byte_ix] & bit_mask) >> bit_ix;
105}
106
107/* Compare two bit masks for equality.
108   Returns 0 if they are equal.  */
109
110int
111cgen_bitset_compare (CGEN_BITSET * mask1, CGEN_BITSET * mask2)
112{
113  if (mask1 == mask2)
114    return 0;
115  if (! mask1 || ! mask2)
116    return 1;
117  if (mask1->length != mask2->length)
118    return 1;
119  return memcmp (mask1->bits, mask2->bits, mask1->length);
120}
121
122/* Test two bit masks for common bits.
123   Returns 1 if a common bit is found.  */
124
125int
126cgen_bitset_intersect_p (CGEN_BITSET * mask1, CGEN_BITSET * mask2)
127{
128  unsigned i, limit;
129
130  if (mask1 == mask2)
131    return 1;
132  if (! mask1 || ! mask2)
133    return 0;
134  limit = mask1->length < mask2->length ? mask1->length : mask2->length;
135
136  for (i = 0; i < limit; ++i)
137    if ((mask1->bits[i] & mask2->bits[i]))
138      return 1;
139
140  return 0;
141}
142
143/* Make a copy of a bit mask.  */
144
145CGEN_BITSET *
146cgen_bitset_copy (CGEN_BITSET * mask)
147{
148  CGEN_BITSET* newmask;
149
150  if (! mask)
151    return NULL;
152  newmask = cgen_bitset_create ((mask->length * 8) - 1);
153  memcpy (newmask->bits, mask->bits, mask->length);
154  return newmask;
155}
156
157/* Combine two bit masks.  */
158
159void
160cgen_bitset_union (CGEN_BITSET * mask1, CGEN_BITSET * mask2,
161		   CGEN_BITSET * result)
162{
163  unsigned i;
164
165  if (! mask1 || ! mask2 || ! result
166      || mask1->length != mask2->length
167      || mask1->length != result->length)
168    return;
169
170  for (i = 0; i < result->length; ++i)
171    result->bits[i] = mask1->bits[i] | mask2->bits[i];
172}
173