From 4abab5ad6c8465a7528ccdd5f49367da05f78bbd Mon Sep 17 00:00:00 2001 From: Vladimir Azarov Date: Tue, 1 Oct 2024 15:47:05 +0200 Subject: Initial version --- src/math/logb.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100644 src/math/logb.c (limited to 'src/math/logb.c') diff --git a/src/math/logb.c b/src/math/logb.c new file mode 100644 index 0000000..7f8bdfa --- /dev/null +++ b/src/math/logb.c @@ -0,0 +1,17 @@ +#include + +/* +special cases: + logb(+-0) = -inf, and raise divbyzero + logb(+-inf) = +inf + logb(nan) = nan +*/ + +double logb(double x) +{ + if (!isfinite(x)) + return x * x; + if (x == 0) + return -1/(x*x); + return ilogb(x); +} -- cgit v1.2.3