sync code with last improvements from OpenBSD

proto/xorgproto/include/X11/extensions/xtrapbits.h

@@ -0,0 +1,83 @@
+/* $XFree86$ */
+/*
+ * This include file is designed to be a portable way for systems to define
+ * bit field manipulation of arrays of bits.
+ */
+#ifndef __XTRAPBITS__
+#define __XTRAPBITS__ "@(#)xtrapbits.h	1.6 - 90/09/18  "
+
+/*****************************************************************************
+Copyright 1987, 1988, 1989, 1990, 1994 by Digital Equipment Corporation,
+Maynard, MA
+
+Permission to use, copy, modify, and distribute this software and its
+documentation for any purpose and without fee is hereby granted,
+provided that the above copyright notice appear in all copies and that
+both that copyright notice and this permission notice appear in
+supporting documentation, and that the name of Digital not be
+used in advertising or publicity pertaining to distribution of the
+software without specific, written prior permission.
+
+DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
+ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
+DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
+ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+SOFTWARE.
+
+*****************************************************************************/
+/*
+ *
+ *  CONTRIBUTORS:
+ *
+ *      Dick Annicchiarico
+ *      Robert Chesler
+ *      Dan Coutu
+ *      Gene Durso
+ *      Marc Evans
+ *      Alan Jamison
+ *      Mark Henry
+ *      Ken Miller
+ *
+ */
+typedef unsigned char *UByteP;  /* Pointer to an unsigned byte array */
+#define BitsInByte    8L        /* The number of bits in a byte */
+
+#define BitInByte(bit)	        /* Returns the bit mask of a byte */ \
+    (1L << (((bit) % BitsInByte)))
+
+#define BitInWord(bit)	        /* Returns the bit mask of a word */ \
+    (1L << (((bit) % (BitsInByte * 2L))))
+
+#define BitInLong(bit)	        /* Returns the bit mask of a long */ \
+    (1L << (((bit) % (BitsInByte * 4L))))
+
+#define ByteInArray(array,bit)	/* Returns the byte offset to get to a bit */ \
+    (((UByteP)(array))[(bit) / BitsInByte])
+
+#define BitIsTrue(array,bit)    /* Test to see if a specific bit is True */ \
+    (ByteInArray(array,bit) & BitInByte(bit))
+
+#define BitIsFalse(array,bit)   /* Test to see if a specific bit is False */ \
+    (!(BitIsTrue(array,bit)))
+
+#define BitTrue(array,bit)      /* Set a specific bit to be True */ \
+    (ByteInArray(array,bit) |= BitInByte(bit))
+
+#define BitFalse(array,bit)     /* Set a specific bit to be False */ \
+    (ByteInArray(array,bit) &= ~BitInByte(bit))
+
+#define BitToggle(array,bit)    /* Toggle a specific bit */ \
+    (ByteInArray(array,bit) ^= BitInByte(bit))
+
+#define BitCopy(dest,src,bit)   /* Copy a specific bit */ \
+    BitIsTrue((src),(bit)) ? BitTrue((dest),(bit)) : BitFalse((dest),(bit))
+
+#define BitValue(array,bit)     /* Return True or False depending on bit */ \
+    (BitIsTrue((array),(bit)) ? True : False)
+
+#define BitSet(array,bit,value) /* Set bit to given value in array */ \
+    (value) ? BitTrue((array),(bit)) : BitFalse((array),(bit))
+
+#endif /* __XTRAPBITS__ */