1 /* CGEN generic opcode support.
2    Copyright (C) 2002-2016 Free Software Foundation, Inc.
3 
4    This file is part of libopcodes.
5 
6    This library 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 3, or (at your option)
9    any later version.
10 
11    It is distributed in the hope that it will be useful, but WITHOUT
12    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
14    License for more details.
15 
16    You should have received a copy of the GNU General Public License along
17    with this program; if not, write to the Free Software Foundation, Inc.,
18    51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
19 
20 /* Functions for manipulating CGEN_BITSET.  */
21 
22 #include "libiberty.h"
23 #include "cgen/bitset.h"
24 #include <string.h>
25 
26 /* Create a bit mask.  */
27 
28 CGEN_BITSET *
cgen_bitset_create(unsigned bit_count)29 cgen_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 
38 void
cgen_bitset_init(CGEN_BITSET * mask,unsigned bit_count)39 cgen_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 
50 void
cgen_bitset_clear(CGEN_BITSET * mask)51 cgen_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 
64 void
cgen_bitset_add(CGEN_BITSET * mask,unsigned bit_num)65 cgen_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 
80 void
cgen_bitset_set(CGEN_BITSET * mask,unsigned bit_num)81 cgen_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 
92 int
cgen_bitset_contains(CGEN_BITSET * mask,unsigned bit_num)93 cgen_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 
110 int
cgen_bitset_compare(CGEN_BITSET * mask1,CGEN_BITSET * mask2)111 cgen_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 
125 int
cgen_bitset_intersect_p(CGEN_BITSET * mask1,CGEN_BITSET * mask2)126 cgen_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 
145 CGEN_BITSET *
cgen_bitset_copy(CGEN_BITSET * mask)146 cgen_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 
159 void
cgen_bitset_union(CGEN_BITSET * mask1,CGEN_BITSET * mask2,CGEN_BITSET * result)160 cgen_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