79 lines
1.7 KiB
C
79 lines
1.7 KiB
C
/**
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* @license Apache-2.0
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*
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* Copyright (c) 2020 The Stdlib Authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "stdlib/blas/base/cswap.h"
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/**
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* Interchanges two complex single-precision floating-point vectors.
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*
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* @param N number of elements to swap
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* @param X first input array
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* @param strideX X stride length
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* @param Y second input array
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* @param strideY Y stride length
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*/
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void c_cswap( const int N, void *X, const int strideX, void *Y, const int strideY ) {
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float *x = (float *)X;
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float *y = (float *)Y;
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float tmp;
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int ix;
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int iy;
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int i;
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int j;
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if ( N <= 0 ) {
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return;
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}
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if ( strideX == 1 && strideY == 1 ) {
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for ( i = 0; i < N*2; i += 2 ) {
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tmp = x[ i ];
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x[ i ] = y[ i ];
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y[ i ] = tmp;
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j = i + 1;
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tmp = x[ j ];
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x[ j ] = y[ j ];
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y[ j ] = tmp;
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}
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return;
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}
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if ( strideX < 0 ) {
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ix = 2 * (1-N) * strideX;
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} else {
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ix = 0;
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}
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if ( strideY < 0 ) {
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iy = 2 * (1-N) * strideY;
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} else {
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iy = 0;
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}
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for ( i = 0; i < N; i++ ) {
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tmp = x[ ix ];
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x[ ix ] = y[ iy ];
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y[ iy ] = tmp;
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tmp = x[ ix+1 ];
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x[ ix+1 ] = y[ iy+1 ];
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y[ iy+1 ] = tmp;
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ix += strideX * 2;
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iy += strideY * 2;
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}
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return;
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}
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