nest-open-source / nest-learning-thermostat / 5.1.5 / nspr / b9c88dc7c668ea75ad01317836850262129c582a / . / nspr-4.8.6 / mozilla / nsprpub / pr / src / misc / prlog2.c

/* -*- 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 ***** */ | |

#include "prbit.h" | |

/* | |

** Compute the log of the least power of 2 greater than or equal to n | |

*/ | |

PR_IMPLEMENT(PRIntn) PR_CeilingLog2(PRUint32 n) | |

{ | |

PRIntn log2; | |

PR_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. | |

*/ | |

PR_IMPLEMENT(PRIntn) PR_FloorLog2(PRUint32 n) | |

{ | |

PRIntn log2; | |

PR_FLOOR_LOG2(log2, n); | |

return log2; | |

} |