lib/lcm.c


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// Lcm
//
// lcm
//
// Least common multiple
//
// lcm(a,b) = |a*b| / gcd(a,b)
//
// Inputs:    2
// Outputs:   1
// Constants: 0


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


ts_parameter_t const ts_lcm_p = { .n_inputs = 2, .n_outputs = 1, .n_constants = 0, .params_size = 0 };

uint_t ts_lcm_offset( ts_constant_t const *c )
{
	( void )c;
	return ( 0 );
}

int ts_lcm(
	fp_t * const *y, uint_t y_n,
	fp_t const * const *x, uint_t x_n,
	uint_t n, ts_constant_t const *c
)
{
	TS_PROLOGUE( ts_lcm_p );
	(void)c;
    for( uint_t i = 0; i < n; ++i )
    {
        fp_t ax = fabs(x[0][i]);
        fp_t bx = fabs(x[1][i]);
        if (ax > 1e15 || bx > 1e15) { y[0][i] = 0.0; continue; }
        long a = (long)ax;
        long b = (long)bx;
        if( !a || !b )
        {
            y[0][i] = 0.0;
        }
        else
        {
            long ta = a;
            long tb = b;
            while( tb )
            {
                long t = tb;
                tb = ta % tb;
                ta = t;
            }
            y[0][i] = (fp_t)(a / ta) * (fp_t)b;
        }
    }
	return 0;
}