1 files changed, 122 insertions, 0 deletions
diff --git a/bitstring.h b/bitstring.h
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index 0000000..d054de3
--- /dev/null
+++ b/bitstring.h
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+/*
+ * Copyright (c) 1989 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Paul Vixie.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that the above copyright notice and this paragraph are
+ * duplicated in all such forms and that any documentation,
+ * advertising materials, and other materials related to such
+ * distribution and use acknowledge that the software was developed
+ * by the University of California, Berkeley.  The name of the
+ * University may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ *	@(#)bitstring.h	5.2 (Berkeley) 4/4/90
+ */
+
+typedef	unsigned char bitstr_t;
+
+/* internal macros */
+				/* byte of the bitstring bit is in */
+#define	_bit_byte(bit) \
+	((bit) >> 3)
+
+				/* mask for the bit within its byte */
+#define	_bit_mask(bit) \
+	(1 << ((bit)&0x7))
+
+/* external macros */
+				/* bytes in a bitstring of nbits bits */
+#define	bitstr_size(nbits) \
+	((((nbits) - 1) >> 3) + 1)
+
+				/* allocate a bitstring */
+#define	bit_alloc(nbits) \
+	(bitstr_t *)malloc(1, \
+	    (unsigned int)bitstr_size(nbits) * sizeof(bitstr_t))
+
+				/* allocate a bitstring on the stack */
+#define	bit_decl(name, nbits) \
+	(name)[bitstr_size(nbits)]
+
+				/* is bit N of bitstring name set? */
+#define	bit_test(name, bit) \
+	((name)[_bit_byte(bit)] & _bit_mask(bit))
+
+				/* set bit N of bitstring name */
+#define	bit_set(name, bit) \
+	(name)[_bit_byte(bit)] |= _bit_mask(bit)
+
+				/* clear bit N of bitstring name */
+#define	bit_clear(name, bit) \
+	(name)[_bit_byte(bit)] &= ~_bit_mask(bit)
+
+				/* clear bits start ... stop in bitstring */
+#define	bit_nclear(name, start, stop) { \
+	register bitstr_t *_name = name; \
+	register int _start = start, _stop = stop; \
+	register int _startbyte = _bit_byte(_start); \
+	register int _stopbyte = _bit_byte(_stop); \
+	if (_startbyte == _stopbyte) { \
+		_name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) | \
+				      (0xff << ((_stop&0x7) + 1))); \
+	} else { \
+		_name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \
+		while (++_startbyte < _stopbyte) \
+			_name[_startbyte] = 0; \
+		_name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \
+	} \
+}
+
+				/* set bits start ... stop in bitstring */
+#define	bit_nset(name, start, stop) { \
+	register bitstr_t *_name = name; \
+	register int _start = start, _stop = stop; \
+	register int _startbyte = _bit_byte(_start); \
+	register int _stopbyte = _bit_byte(_stop); \
+	if (_startbyte == _stopbyte) { \
+		_name[_startbyte] |= ((0xff << (_start&0x7)) & \
+				    (0xff >> (7 - (_stop&0x7)))); \
+	} else { \
+		_name[_startbyte] |= 0xff << ((_start)&0x7); \
+		while (++_startbyte < _stopbyte) \
+	    		_name[_startbyte] = 0xff; \
+		_name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \
+	} \
+}
+
+				/* find first bit clear in name */
+#define	bit_ffc(name, nbits, value) { \
+	register bitstr_t *_name = name; \
+	register int _byte, _nbits = nbits; \
+	register int _stopbyte = _bit_byte(_nbits), _value = -1; \
+	for (_byte = 0; _byte <= _stopbyte; ++_byte) \
+		if (_name[_byte] != 0xff) { \
+			_value = _byte << 3; \
+			for (_stopbyte = _name[_byte]; (_stopbyte&0x1); \
+			    ++_value, _stopbyte >>= 1); \
+			break; \
+		} \
+	*(value) = _value; \
+}
+
+				/* find first bit set in name */
+#define	bit_ffs(name, nbits, value) { \
+	register bitstr_t *_name = name; \
+	register int _byte, _nbits = nbits; \
+	register int _stopbyte = _bit_byte(_nbits), _value = -1; \
+	for (_byte = 0; _byte <= _stopbyte; ++_byte) \
+		if (_name[_byte]) { \
+			_value = _byte << 3; \
+			for (_stopbyte = _name[_byte]; !(_stopbyte&0x1); \
+			    ++_value, _stopbyte >>= 1); \
+			break; \
+		} \
+	*(value) = _value; \
+}