1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* This Source Code Form is subject to the terms of the Mozilla Public
3  * License, v. 2.0. If a copy of the MPL was not distributed with this
4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5 
6 #include "prbit.h"
7 
8 /*
9 ** Compute the log of the least power of 2 greater than or equal to n
10 */
PR_CeilingLog2(PRUint32 n)11 PR_IMPLEMENT(PRIntn) PR_CeilingLog2(PRUint32 n)
12 {
13     PRIntn log2;
14     PR_CEILING_LOG2(log2, n);
15     return log2;
16 }
17 
18 /*
19 ** Compute the log of the greatest power of 2 less than or equal to n.
20 ** This really just finds the highest set bit in the word.
21 */
PR_FloorLog2(PRUint32 n)22 PR_IMPLEMENT(PRIntn) PR_FloorLog2(PRUint32 n)
23 {
24     PRIntn log2;
25     PR_FLOOR_LOG2(log2, n);
26     return log2;
27 }
28