1*c9945492SAndroid Build Coastguard Worker #define _GNU_SOURCE
2*c9945492SAndroid Build Coastguard Worker #include <math.h>
3*c9945492SAndroid Build Coastguard Worker #include <stdint.h>
4*c9945492SAndroid Build Coastguard Worker
exp10f(float x)5*c9945492SAndroid Build Coastguard Worker float exp10f(float x)
6*c9945492SAndroid Build Coastguard Worker {
7*c9945492SAndroid Build Coastguard Worker static const float p10[] = {
8*c9945492SAndroid Build Coastguard Worker 1e-7f, 1e-6f, 1e-5f, 1e-4f, 1e-3f, 1e-2f, 1e-1f,
9*c9945492SAndroid Build Coastguard Worker 1, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7
10*c9945492SAndroid Build Coastguard Worker };
11*c9945492SAndroid Build Coastguard Worker float n, y = modff(x, &n);
12*c9945492SAndroid Build Coastguard Worker union {float f; uint32_t i;} u = {n};
13*c9945492SAndroid Build Coastguard Worker /* fabsf(n) < 8 without raising invalid on nan */
14*c9945492SAndroid Build Coastguard Worker if ((u.i>>23 & 0xff) < 0x7f+3) {
15*c9945492SAndroid Build Coastguard Worker if (!y) return p10[(int)n+7];
16*c9945492SAndroid Build Coastguard Worker y = exp2f(3.32192809488736234787031942948939f * y);
17*c9945492SAndroid Build Coastguard Worker return y * p10[(int)n+7];
18*c9945492SAndroid Build Coastguard Worker }
19*c9945492SAndroid Build Coastguard Worker return exp2(3.32192809488736234787031942948939 * x);
20*c9945492SAndroid Build Coastguard Worker }
21*c9945492SAndroid Build Coastguard Worker
22*c9945492SAndroid Build Coastguard Worker weak_alias(exp10f, pow10f);
23