time-to-botec

Benchmark sampling in different programming languages
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ndarray.js (1881B)

      1 /**
      2 * @license Apache-2.0
      3 *
      4 * Copyright (c) 2020 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 // VARIABLES //
     22 
     23 var M = 5;
     24 
     25 
     26 // MAIN //
     27 
     28 /**
     29 * Adds a constant to each element in a strided array.
     30 *
     31 * @param {PositiveInteger} N - number of indexed elements
     32 * @param {number} alpha - scalar
     33 * @param {NumericArray} x - input array
     34 * @param {integer} stride - index increment
     35 * @param {NonNegativeInteger} offset - starting index
     36 * @returns {NumericArray} input array
     37 *
     38 * @example
     39 * var x = [ 1.0, -2.0, 3.0, -4.0, 5.0, -6.0 ];
     40 * var alpha = 5.0;
     41 *
     42 * gapx( 3, alpha, x, 1, x.length-3 );
     43 * // x => [ 1.0, -2.0, 3.0, 1.0, 10.0, -1.0 ]
     44 */
     45 function gapx( N, alpha, x, stride, offset ) {
     46 	var ix;
     47 	var m;
     48 	var i;
     49 
     50 	if ( N <= 0 || alpha === 0.0 ) {
     51 		return x;
     52 	}
     53 	ix = offset;
     54 
     55 	// Use loop unrolling if the stride is equal to `1`...
     56 	if ( stride === 1 ) {
     57 		m = N % M;
     58 
     59 		// If we have a remainder, run a clean-up loop...
     60 		if ( m > 0 ) {
     61 			for ( i = 0; i < m; i++ ) {
     62 				x[ ix ] += alpha;
     63 				ix += stride;
     64 			}
     65 		}
     66 		if ( N < M ) {
     67 			return x;
     68 		}
     69 		for ( i = m; i < N; i += M ) {
     70 			x[ ix ] += alpha;
     71 			x[ ix+1 ] += alpha;
     72 			x[ ix+2 ] += alpha;
     73 			x[ ix+3 ] += alpha;
     74 			x[ ix+4 ] += alpha;
     75 			ix += M;
     76 		}
     77 		return x;
     78 	}
     79 	for ( i = 0; i < N; i++ ) {
     80 		x[ ix ] += alpha;
     81 		ix += stride;
     82 	}
     83 	return x;
     84 }
     85 
     86 
     87 // EXPORTS //
     88 
     89 module.exports = gapx;