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/* Bitset primitives used by the parser generator */
#include "pgenheaders.h"
#include "bitset.h"
bitset
newbitset(nbits)
int nbits;
{
int nbytes = NBYTES(nbits);
bitset ss = NEW(BYTE, nbytes);
if (ss == NULL)
fatal("no mem for bitset");
ss += nbytes;
while (--nbytes >= 0)
*--ss = 0;
return ss;
}
void
delbitset(ss)
bitset ss;
{
DEL(ss);
}
int
addbit(ss, ibit)
bitset ss;
int ibit;
{
int ibyte = BIT2BYTE(ibit);
BYTE mask = BIT2MASK(ibit);
if (ss[ibyte] & mask)
return 0; /* Bit already set */
ss[ibyte] |= mask;
return 1;
}
#if 0 /* Now a macro */
int
testbit(ss, ibit)
bitset ss;
int ibit;
{
return (ss[BIT2BYTE(ibit)] & BIT2MASK(ibit)) != 0;
}
#endif
int
samebitset(ss1, ss2, nbits)
bitset ss1, ss2;
int nbits;
{
int i;
for (i = NBYTES(nbits); --i >= 0; )
if (*ss1++ != *ss2++)
return 0;
return 1;
}
void
mergebitset(ss1, ss2, nbits)
bitset ss1, ss2;
int nbits;
{
int i;
for (i = NBYTES(nbits); --i >= 0; )
*ss1++ |= *ss2++;
}
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