time-to-botec

Benchmark sampling in different programming languages
Log | Files | Refs | README

is_pow2.js (1068B)

      1 /**
      2 * @license Apache-2.0
      3 *
      4 * Copyright (c) 2018 The Stdlib Authors.
      5 *
      6 * Licensed under the Apache License, Version 2.0 (the "License");
      7 * you may not use this file except in compliance with the License.
      8 * You may obtain a copy of the License at
      9 *
     10 *    http://www.apache.org/licenses/LICENSE-2.0
     11 *
     12 * Unless required by applicable law or agreed to in writing, software
     13 * distributed under the License is distributed on an "AS IS" BASIS,
     14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     15 * See the License for the specific language governing permissions and
     16 * limitations under the License.
     17 */
     18 
     19 'use strict';
     20 
     21 // MAIN //
     22 
     23 /**
     24 * Tests whether an unsigned integer is a power of 2.
     25 *
     26 * @param {uinteger32} x - value to test
     27 * @returns {boolean} boolean indicating whether a value is a power of 2
     28 *
     29 * @example
     30 * var bool = isPow2Uint32( 2 );
     31 * // returns true
     32 *
     33 * @example
     34 * var bool = isPow2Uint32( 5 );
     35 * // returns false
     36 */
     37 function isPow2Uint32( x ) {
     38 	x >>>= 0;
     39 	return ( !!x && !(x & (x-1)));
     40 }
     41 
     42 
     43 // EXPORTS //
     44 
     45 module.exports = isPow2Uint32;