time-to-botec

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

normalize.js (2318B)

      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 // MODULES //
     22 
     23 var FLOAT32_SMALLEST_NORMAL = require( '@stdlib/constants/float32/smallest-normal' );
     24 var PINF = require( '@stdlib/constants/float32/pinf' );
     25 var NINF = require( '@stdlib/constants/float32/ninf' );
     26 var abs = require( '@stdlib/math/base/special/abs' );
     27 var toFloat32 = require( './../../../../float64/base/to-float32' );
     28 
     29 
     30 // VARIABLES //
     31 
     32 // (1<<32)
     33 var SCALAR = 8388608;
     34 
     35 
     36 // MAIN //
     37 
     38 /**
     39 * Returns a normal number `y` and exponent `exp` satisfying \\(x = y \cdot 2^\mathrm{exp}\\).
     40 *
     41 * @private
     42 * @param {(Array|TypedArray|Object)} out - output array
     43 * @param {number} x - single-precision floating-point number
     44 * @returns {(Array|TypedArray|Object)} output array
     45 *
     46 * @example
     47 * var toFloat32 = require( '@stdlib/number/float64/base/to-float32' );
     48 *
     49 * var v = normalizef( [ 0.0, 0 ], toFloat32( 1.401e-45 ) );
     50 * // returns [ 1.1754943508222875e-38, -23 ]
     51 *
     52 * @example
     53 * var v = normalizef( [ 0.0, 0 ], 0.0 );
     54 * // returns [ 0.0, 0 ];
     55 *
     56 * @example
     57 * var PINF = require( '@stdlib/constants/float32/pinf' );
     58 *
     59 * var v = normalizef( [ 0.0, 0 ], PINF );
     60 * // returns [ +Infinity, 0 ]
     61 *
     62 * @example
     63 * var NINF = require( '@stdlib/constants/float32/ninf' );
     64 *
     65 * var v = normalizef( [ 0.0, 0 ], NINF );
     66 * // returns [ -Infinity, 0 ]
     67 *
     68 * @example
     69 * var v = normalizef( [ 0.0, 0 ], NaN );
     70 * // returns [ NaN, 0 ]
     71 */
     72 function normalizef( out, x ) {
     73 	if (
     74 		x !== x ||
     75 		x === PINF ||
     76 		x === NINF
     77 	) {
     78 		out[ 0 ] = x;
     79 		out[ 1 ] = 0;
     80 		return out;
     81 	}
     82 	if ( x !== 0.0 && abs( x ) < FLOAT32_SMALLEST_NORMAL ) {
     83 		x = toFloat32( x*SCALAR );
     84 		out[ 0 ] = x;
     85 		out[ 1 ] = -23;
     86 		return out;
     87 	}
     88 	out[ 0 ] = x;
     89 	out[ 1 ] = 0;
     90 	return out;
     91 }
     92 
     93 
     94 // EXPORTS //
     95 
     96 module.exports = normalizef;