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-rw-r--r--Parser/bitset.c76
1 files changed, 76 insertions, 0 deletions
diff --git a/Parser/bitset.c b/Parser/bitset.c
new file mode 100644
index 0000000..b43fb82
--- /dev/null
+++ b/Parser/bitset.c
@@ -0,0 +1,76 @@
+/* Bitset primitives */
+
+#include "PROTO.h"
+#include "malloc.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++;
+}