Security-57031.1.35.tar.gz

[apple/security.git] / Security / libsecurity_asn1 / lib / prbit.h

diff --git a/Security/libsecurity_asn1/lib/prbit.h b/Security/libsecurity_asn1/lib/prbit.h
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 
+ * 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 Netscape are 
+ * Copyright (C) 1998-2000 Netscape Communications Corporation.  All
+ * Rights Reserved.
+ * 
+ * Contributor(s):
+ * 
+ * Alternatively, the contents of this file may be used under the
+ * terms of the GNU General Public License Version 2 or later (the
+ * "GPL"), in which case the provisions of the GPL are applicable 
+ * instead of those above.  If you wish to allow use of your 
+ * version of this file only under the terms of the GPL and not to
+ * allow others to use your version of this file under the MPL,
+ * indicate your decision by deleting the provisions above and
+ * replace them with the notice and other provisions required by
+ * the GPL.  If you do not delete the provisions above, a recipient
+ * may use your version of this file under either the MPL or the
+ * GPL.
+ */
+
+#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___ */