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