/js/lib/Socket.IO-node/support/expresso/deps/jscoverage/js/jslog2.cpp
http://github.com/onedayitwillmake/RealtimeMultiplayerNodeJs · C++ · 94 lines · 36 code · 11 blank · 47 comment · 13 complexity · 7d9741b11f97c6ef5cf1caeab2bdd399 MD5 · raw file
- /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
- /* ***** 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 Mozilla Communicator client code, released
- * March 31, 1998.
- *
- * The Initial Developer of the Original Code is
- * Netscape Communications Corporation.
- * Portions created by the Initial Developer are Copyright (C) 1998
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either of 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 ***** */
- #include "jsstddef.h"
- #include "jsbit.h"
- #include "jsutil.h"
- /*
- ** Compute the log of the least power of 2 greater than or equal to n
- */
- JS_PUBLIC_API(JSIntn) JS_CeilingLog2(JSUint32 n)
- {
- JSIntn log2;
- JS_CEILING_LOG2(log2, n);
- return log2;
- }
- /*
- ** Compute the log of the greatest power of 2 less than or equal to n.
- ** This really just finds the highest set bit in the word.
- */
- JS_PUBLIC_API(JSIntn) JS_FloorLog2(JSUint32 n)
- {
- JSIntn log2;
- JS_FLOOR_LOG2(log2, n);
- return log2;
- }
- /*
- * js_FloorLog2wImpl has to be defined only for 64-bit non-GCC case.
- */
- #if !defined(JS_HAS_BUILTIN_BITSCAN64) && JS_BYTES_PER_WORD == 8
- JSUword
- js_FloorLog2wImpl(JSUword n)
- {
- JSUword log2, m;
- JS_ASSERT(n != 0);
- log2 = 0;
- m = n >> 32;
- if (m != 0) { n = m; log2 = 32; }
- m = n >> 16;
- if (m != 0) { n = m; log2 |= 16; }
- m = n >> 8;
- if (m != 0) { n = m; log2 |= 8; }
- m = n >> 4;
- if (m != 0) { n = m; log2 |= 4; }
- m = n >> 2;
- if (m != 0) { n = m; log2 |= 2; }
- log2 |= (n >> 1);
- return log2;
- }
- #endif