dcopy.c (1766B)
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 #include "stdlib/blas/base/dcopy.h" 20 21 /** 22 * Copies values from `X` into `Y`. 23 * 24 * @param N number of elements to copy 25 * @param X input array 26 * @param strideX X stride length 27 * @param Y destination array 28 * @param strideY Y stride length 29 */ 30 void c_dcopy( const int N, const double *X, const int strideX, double *Y, const int strideY ) { 31 int ix; 32 int iy; 33 int i; 34 int m; 35 36 if ( N <= 0 ) { 37 return; 38 } 39 // If both strides are equal to `1`, use unrolled loops... 40 if ( strideX == 1 && strideY == 1 ) { 41 m = N % 7; 42 43 // If we have a remainder, do a clean-up loop... 44 if ( m > 0 ) { 45 for ( i = 0; i < m; i++ ) { 46 Y[ i ] = X[ i ]; 47 } 48 if ( N < 7 ) { 49 return; 50 } 51 } 52 for ( i = m; i < N; i += 7 ) { 53 Y[ i ] = X[ i ]; 54 Y[ i+1 ] = X[ i+1 ]; 55 Y[ i+2 ] = X[ i+2 ]; 56 Y[ i+3 ] = X[ i+3 ]; 57 Y[ i+4 ] = X[ i+4 ]; 58 Y[ i+5 ] = X[ i+5 ]; 59 Y[ i+6 ] = X[ i+6 ]; 60 } 61 return; 62 } 63 if ( strideX < 0 ) { 64 ix = (1-N) * strideX; 65 } else { 66 ix = 0; 67 } 68 if ( strideY < 0 ) { 69 iy = (1-N) * strideY; 70 } else { 71 iy = 0; 72 } 73 for ( i = 0; i < N; i++ ) { 74 Y[ iy ] = X[ ix ]; 75 ix += strideX; 76 iy += strideY; 77 } 78 return; 79 }