1 /* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <audio_utils/roundup.h> 18 19 unsigned roundup(unsigned v) 20 { 21 // __builtin_clz is undefined for zero input 22 if (v == 0) { 23 v = 1; 24 } 25 int lz = __builtin_clz((int) v); 26 unsigned rounded = ((unsigned) 0x80000000) >> lz; 27 // 0x800000001 and higher are actually rounded _down_ to prevent overflow 28 if (v > rounded && lz > 0) { 29 rounded <<= 1; 30 } 31 return rounded; 32 } 33
