Version 1.8 of gecko-sdk. Downloaded from here:...

gecko-sdk/include/prbit.h

+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is the Netscape Portable Runtime (NSPR).
+ *
+ * The Initial Developer of the Original Code is
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 1998-2000
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef prbit_h___
+#define prbit_h___
+
+#include "prtypes.h"
+PR_BEGIN_EXTERN_C
+
+/*
+** A prbitmap_t is a long integer that can be used for bitmaps
+*/
+typedef unsigned long prbitmap_t;
+
+#define PR_TEST_BIT(_map,_bit) \
+    ((_map)[(_bit)>>PR_BITS_PER_LONG_LOG2] & (1L << ((_bit) & (PR_BITS_PER_LONG-1))))
+#define PR_SET_BIT(_map,_bit) \
+    ((_map)[(_bit)>>PR_BITS_PER_LONG_LOG2] |= (1L << ((_bit) & (PR_BITS_PER_LONG-1))))
+#define PR_CLEAR_BIT(_map,_bit) \
+    ((_map)[(_bit)>>PR_BITS_PER_LONG_LOG2] &= ~(1L << ((_bit) & (PR_BITS_PER_LONG-1))))
+
+/*
+** Compute the log of the least power of 2 greater than or equal to n
+*/
+NSPR_API(PRIntn) PR_CeilingLog2(PRUint32 i); 
+
+/*
+** Compute the log of the greatest power of 2 less than or equal to n
+*/
+NSPR_API(PRIntn) PR_FloorLog2(PRUint32 i); 
+
+/*
+** Macro version of PR_CeilingLog2: Compute the log of the least power of
+** 2 greater than or equal to _n. The result is returned in _log2.
+*/
+#define PR_CEILING_LOG2(_log2,_n)   \
+  PR_BEGIN_MACRO                    \
+    PRUint32 j_ = (PRUint32)(_n);       \
+    (_log2) = 0;                    \
+    if ((j_) & ((j_)-1))            \
+        (_log2) += 1;               \
+    if ((j_) >> 16)                 \
+        (_log2) += 16, (j_) >>= 16; \
+    if ((j_) >> 8)                  \
+        (_log2) += 8, (j_) >>= 8;   \
+    if ((j_) >> 4)                  \
+        (_log2) += 4, (j_) >>= 4;   \
+    if ((j_) >> 2)                  \
+        (_log2) += 2, (j_) >>= 2;   \
+    if ((j_) >> 1)                  \
+        (_log2) += 1;               \
+  PR_END_MACRO
+
+/*
+** Macro version of PR_FloorLog2: Compute the log of the greatest power of
+** 2 less than or equal to _n. The result is returned in _log2.
+**
+** This is equivalent to finding the highest set bit in the word.
+*/
+#define PR_FLOOR_LOG2(_log2,_n)   \
+  PR_BEGIN_MACRO                    \
+    PRUint32 j_ = (PRUint32)(_n);       \
+    (_log2) = 0;                    \
+    if ((j_) >> 16)                 \
+        (_log2) += 16, (j_) >>= 16; \
+    if ((j_) >> 8)                  \
+        (_log2) += 8, (j_) >>= 8;   \
+    if ((j_) >> 4)                  \
+        (_log2) += 4, (j_) >>= 4;   \
+    if ((j_) >> 2)                  \
+        (_log2) += 2, (j_) >>= 2;   \
+    if ((j_) >> 1)                  \
+        (_log2) += 1;               \
+  PR_END_MACRO
+
+PR_END_EXTERN_C
+#endif /* prbit_h___ */