1#define _GNU_SOURCE
 2#include <math.h>
 3#include <stdint.h>
 4
 5float exp10f(float x)
 6{
 7	static const float p10[] = {
 8		1e-7f, 1e-6f, 1e-5f, 1e-4f, 1e-3f, 1e-2f, 1e-1f,
 9		1, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7
10	};
11	float n, y = modff(x, &n);
12	union {float f; uint32_t i;} u = {n};
13	/* fabsf(n) < 8 without raising invalid on nan */
14	if ((u.i>>23 & 0xff) < 0x7f+3) {
15		if (!y) return p10[(int)n+7];
16		y = exp2f(3.32192809488736234787031942948939f * y);
17		return y * p10[(int)n+7];
18	}
19	return exp2(3.32192809488736234787031942948939 * x);
20}
21
22weak_alias(exp10f, pow10f);