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v0.5.1
https://github.com/python/cpython
09 December 2020, 11:06:31 UTC
Revision a920961673c5589ca8aae6652b1563a651daf80f authored by Mark Dickinson on 14 February 2010, 13:08:35 UTC, committed by Mark Dickinson on 14 February 2010, 13:08:35 UTC 
Merged revisions 78183-78184 via svnmerge from
 
svn+ssh://pythondev@svn.python.org/python/trunk

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  r78183 | mark.dickinson | 2010-02-14 12:16:43 +0000 (Sun, 14 Feb 2010) | 1 line

  Silence some 'comparison between signed and unsigned' compiler warnings.
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  r78184 | mark.dickinson | 2010-02-14 12:31:26 +0000 (Sun, 14 Feb 2010) | 1 line

  Silence more compiler warnings;  fix an instance of potential undefined behaviour from signed overflow.
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Tip revision: a920961673c5589ca8aae6652b1563a651daf80f authored by Mark Dickinson on 14 February 2010, 13:08:35 UTC
Merged revisions 78183-78184 via svnmerge from
Tip revision: a920961
bitset.c 

/* Bitset primitives used by the parser generator */

#include "pgenheaders.h"
#include "bitset.h"

bitset
newbitset(int nbits)
{
	int nbytes = NBYTES(nbits);
	bitset ss = (char *)PyObject_MALLOC(sizeof(BYTE) *  nbytes);
	
	if (ss == NULL)
		Py_FatalError("no mem for bitset");
	
	ss += nbytes;
	while (--nbytes >= 0)
		*--ss = 0;
	return ss;
}

void
delbitset(bitset ss)
{
	PyObject_FREE(ss);
}

int
addbit(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(bitset ss, int ibit)
{
	return (ss[BIT2BYTE(ibit)] & BIT2MASK(ibit)) != 0;
}
#endif

int
samebitset(bitset ss1, bitset ss2, int nbits)
{
	int i;
	
	for (i = NBYTES(nbits); --i >= 0; )
		if (*ss1++ != *ss2++)
			return 0;
	return 1;
}

void
mergebitset(bitset ss1, bitset ss2, int nbits)
{
	int i;
	
	for (i = NBYTES(nbits); --i >= 0; )
		*ss1++ |= *ss2++;
}
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