main.js (2059B)
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 // VARIABLES // 22 23 var M = 8; 24 25 26 // MAIN // 27 28 /** 29 * Copies values from `x` into `y`. 30 * 31 * @param {PositiveInteger} N - number of values to copy 32 * @param {NumericArray} x - input array 33 * @param {integer} strideX - `x` stride length 34 * @param {NumericArray} y - destination array 35 * @param {integer} strideY - `y` stride length 36 * @returns {NumericArray} `y` 37 * 38 * @example 39 * var x = [ 1.0, 2.0, 3.0, 4.0, 5.0 ]; 40 * var y = [ 6.0, 7.0, 8.0, 9.0, 10.0 ]; 41 * 42 * gcopy( x.length, x, 1, y, 1 ); 43 * // y => [ 1.0, 2.0, 3.0, 4.0, 5.0 ] 44 */ 45 function gcopy( N, x, strideX, y, strideY ) { 46 var ix; 47 var iy; 48 var m; 49 var i; 50 if ( N <= 0 ) { 51 return y; 52 } 53 // Use unrolled loops if both strides are equal to `1`... 54 if ( strideX === 1 && strideY === 1 ) { 55 m = N % M; 56 57 // If we have a remainder, run a clean-up loop... 58 if ( m > 0 ) { 59 for ( i = 0; i < m; i++ ) { 60 y[ i ] = x[ i ]; 61 } 62 } 63 if ( N < M ) { 64 return y; 65 } 66 for ( i = m; i < N; i += M ) { 67 y[ i ] = x[ i ]; 68 y[ i+1 ] = x[ i+1 ]; 69 y[ i+2 ] = x[ i+2 ]; 70 y[ i+3 ] = x[ i+3 ]; 71 y[ i+4 ] = x[ i+4 ]; 72 y[ i+5 ] = x[ i+5 ]; 73 y[ i+6 ] = x[ i+6 ]; 74 y[ i+7 ] = x[ i+7 ]; 75 } 76 return y; 77 } 78 if ( strideX < 0 ) { 79 ix = (1-N) * strideX; 80 } else { 81 ix = 0; 82 } 83 if ( strideY < 0 ) { 84 iy = (1-N) * strideY; 85 } else { 86 iy = 0; 87 } 88 for ( i = 0; i < N; i++ ) { 89 y[ iy ] = x[ ix ]; 90 ix += strideX; 91 iy += strideY; 92 } 93 return y; 94 } 95 96 97 // EXPORTS // 98 99 module.exports = gcopy;