diff options
Diffstat (limited to 'libc-top-half/musl/src/math/exp10.c')
-rw-r--r-- | libc-top-half/musl/src/math/exp10.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/libc-top-half/musl/src/math/exp10.c b/libc-top-half/musl/src/math/exp10.c new file mode 100644 index 0000000..26899eb --- /dev/null +++ b/libc-top-half/musl/src/math/exp10.c @@ -0,0 +1,24 @@ +#define _GNU_SOURCE +#include <math.h> +#include <stdint.h> + +double exp10(double x) +{ + static const double p10[] = { + 1e-15, 1e-14, 1e-13, 1e-12, 1e-11, 1e-10, + 1e-9, 1e-8, 1e-7, 1e-6, 1e-5, 1e-4, 1e-3, 1e-2, 1e-1, + 1, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9, + 1e10, 1e11, 1e12, 1e13, 1e14, 1e15 + }; + double n, y = modf(x, &n); + union {double f; uint64_t i;} u = {n}; + /* fabs(n) < 16 without raising invalid on nan */ + if ((u.i>>52 & 0x7ff) < 0x3ff+4) { + if (!y) return p10[(int)n+15]; + y = exp2(3.32192809488736234787031942948939 * y); + return y * p10[(int)n+15]; + } + return pow(10.0, x); +} + +weak_alias(exp10, pow10); |