github.com/afumu/libc@v0.0.6/musl/src/math/exp10f.c (about) 1 #define _GNU_SOURCE 2 #include <math.h> 3 #include <stdint.h> 4 5 float 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 22 weak_alias(exp10f, pow10f);