orca/cstdlib/src/sqrt_data.h

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2023-06-29 01:43:52 +00:00
#ifndef _SQRT_DATA_H
#define _SQRT_DATA_H
#include <features.h>
#include <stdint.h>
/* if x in [1,2): i = (int)(64*x);
if x in [2,4): i = (int)(32*x-64);
__rsqrt_tab[i]*2^-16 is estimating 1/sqrt(x) with small relative error:
|__rsqrt_tab[i]*0x1p-16*sqrt(x) - 1| < -0x1.fdp-9 < 2^-8 */
extern const uint16_t __rsqrt_tab[128];
#endif