1
2/* Bitset primitives used by the parser generator */
3
4#include "pgenheaders.h"
5#include "bitset.h"
6
7bitset
8newbitset(int nbits)
9{
10    int nbytes = NBYTES(nbits);
11    bitset ss = (char *)PyObject_MALLOC(sizeof(BYTE) *  nbytes);
12
13    if (ss == NULL)
14        Py_FatalError("no mem for bitset");
15
16    ss += nbytes;
17    while (--nbytes >= 0)
18        *--ss = 0;
19    return ss;
20}
21
22void
23delbitset(bitset ss)
24{
25    PyObject_FREE(ss);
26}
27
28int
29addbit(bitset ss, int ibit)
30{
31    int ibyte = BIT2BYTE(ibit);
32    BYTE mask = BIT2MASK(ibit);
33
34    if (ss[ibyte] & mask)
35        return 0; /* Bit already set */
36    ss[ibyte] |= mask;
37    return 1;
38}
39
40#if 0 /* Now a macro */
41int
42testbit(bitset ss, int ibit)
43{
44    return (ss[BIT2BYTE(ibit)] & BIT2MASK(ibit)) != 0;
45}
46#endif
47
48int
49samebitset(bitset ss1, bitset ss2, int nbits)
50{
51    int i;
52
53    for (i = NBYTES(nbits); --i >= 0; )
54        if (*ss1++ != *ss2++)
55            return 0;
56    return 1;
57}
58
59void
60mergebitset(bitset ss1, bitset ss2, int nbits)
61{
62    int i;
63
64    for (i = NBYTES(nbits); --i >= 0; )
65        *ss1++ |= *ss2++;
66}
67