Line data    Source code

       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             : */
      11             : PR_IMPLEMENT(PRIntn) PR_CeilingLog2(PRUint32 n)
      12             : {
      13             :     PRIntn log2;
      14          91 :     PR_CEILING_LOG2(log2, n);
      15          91 :     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             : */
      22             : PR_IMPLEMENT(PRIntn) PR_FloorLog2(PRUint32 n)
      23             : {
      24             :     PRIntn log2;
      25           0 :     PR_FLOOR_LOG2(log2, n);
      26           0 :     return log2;
      27             : }