#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 hidden const uint16_t __rsqrt_tab[128]; | |
#endif |