98 lines
2.5 KiB
C
98 lines
2.5 KiB
C
/***************************************************************************
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Copyright (c) 2016, The OpenBLAS Project
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are
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met:
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1. Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in
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the documentation and/or other materials provided with the
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distribution.
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3. Neither the name of the OpenBLAS project nor the names of
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its contributors may be used to endorse or promote products
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derived from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE OPENBLAS PROJECT OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
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USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*****************************************************************************/
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#include "common.h"
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#include <math.h>
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#if defined(DOUBLE)
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#define ABS fabs
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#else
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#define ABS fabsf
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#endif
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FLOAT CNAME(BLASLONG n, FLOAT *x, BLASLONG inc_x)
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{
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BLASLONG i=0;
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FLOAT scale = 0.0;
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FLOAT ssq = 1.0;
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BLASLONG inc_x2;
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FLOAT temp;
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if (n <= 0 || inc_x <= 0) return(0.0);
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inc_x2 = 2 * inc_x;
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n *= inc_x2;
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while(i < n)
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{
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if ( x[i] != 0.0 )
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{
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temp = ABS( x[i] );
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if ( scale < temp )
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{
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ssq = 1 + ssq * ( scale / temp ) * ( scale / temp );
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scale = temp ;
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}
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else
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{
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ssq += ( temp / scale ) * ( temp / scale );
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}
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}
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if ( x[i+1] != 0.0 )
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{
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temp = ABS( x[i+1] );
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if ( scale < temp )
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{
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ssq = 1 + ssq * ( scale / temp ) * ( scale / temp );
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scale = temp ;
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}
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else
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{
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ssq += ( temp / scale ) * ( temp / scale );
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}
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}
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i += inc_x2;
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}
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scale = scale * sqrt( ssq );
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return(scale);
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}
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