X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=blobdiff_plain;f=src%2Fmath%2Flogb.c;h=624425a81165b219a973dee4c3d0f6cbe2c3c43c;hp=f7cd7613069bc172c345bada309a3151a016cfab;hb=52bcf3f5fb3251dca4df5b97b01543160340b31b;hpb=37aa7f7301d6526c14635375886acd881b471f6c diff --git a/src/math/logb.c b/src/math/logb.c index f7cd7613..624425a8 100644 --- a/src/math/logb.c +++ b/src/math/logb.c @@ -1,20 +1,17 @@ -#include #include "libm.h" /* special cases: - logb(+-0) = -inf + logb(+-0) = -inf, and raise divbyzero logb(+-inf) = +inf logb(nan) = nan -these are calculated at runtime to raise fp exceptions */ -double logb(double x) { - int i = ilogb(x); - - if (i == FP_ILOGB0) - return -1.0/fabs(x); - if (i == FP_ILOGBNAN || i == INT_MAX) +double logb(double x) +{ + if (!isfinite(x)) return x * x; - return i; + if (x == 0) + return -1/(x+0); + return ilogb(x); }