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.  */
29 CGEN_BITSET *
cgen_bitset_create(unsigned bit_count)30 cgen_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 
39 void
cgen_bitset_init(CGEN_BITSET * mask,unsigned bit_count)40 cgen_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 
51 void
cgen_bitset_clear(CGEN_BITSET * mask)52 cgen_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 
65 void
cgen_bitset_add(CGEN_BITSET * mask,unsigned bit_num)66 cgen_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 
81 void
cgen_bitset_set(CGEN_BITSET * mask,unsigned bit_num)82 cgen_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 
93 int
cgen_bitset_contains(CGEN_BITSET * mask,unsigned bit_num)94 cgen_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 
111 int
cgen_bitset_compare(CGEN_BITSET * mask1,CGEN_BITSET * mask2)112 cgen_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 
126 int
cgen_bitset_intersect_p(CGEN_BITSET * mask1,CGEN_BITSET * mask2)127 cgen_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 
146 CGEN_BITSET *
cgen_bitset_copy(CGEN_BITSET * mask)147 cgen_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 
160 void
cgen_bitset_union(CGEN_BITSET * mask1,CGEN_BITSET * mask2,CGEN_BITSET * result)161 cgen_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