blob: 1d552d1acef41f579b06d54ace45705b9043980d [file] [log] [blame]
/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <media/nbaio/roundup.h>
unsigned roundup(unsigned v)
{
// __builtin_clz is undefined for zero input
if (v == 0) {
v = 1;
}
int lz = __builtin_clz((int) v);
unsigned rounded = ((unsigned) 0x80000000) >> lz;
// 0x800000001 and higher are actually rounded _down_ to prevent overflow
if (v > rounded && lz > 0) {
rounded <<= 1;
}
return rounded;
}