OpenBLAS/kernel/riscv64/izamax.c

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/**************************************************************************************
* 2013/09/14 Saar
*	 BLASTEST float		: NoTest
* 	 BLASTEST double	: NoTest
* 	 CTEST			: OK
* 	 TEST			: OK
*
**************************************************************************************/

#include "common.h"
#include <math.h>

#if defined(DOUBLE)

#define ABS fabs

#else

#define ABS fabsf

#endif

#define CABS1(x,i)	ABS(x[i])+ABS(x[i+1])

BLASLONG CNAME(BLASLONG n, FLOAT *x, BLASLONG inc_x)
{
	BLASLONG i=0;
	BLASLONG ix=0;
	FLOAT maxf;
	BLASLONG max=0;
	BLASLONG inc_x2;

	if (n <= 0 || inc_x <= 0) return(max);

	inc_x2 = 2 * inc_x;

	maxf = CABS1(x,0);
	ix += inc_x2;
	i++;

	while(i < n)
	{
		if( CABS1(x,ix) > maxf )
		{
			max = i;
			maxf = CABS1(x,ix);
		}
		ix += inc_x2;
		i++;
	}
	return(max+1);
}