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| author | Rich Felker <dalias@aerifal.cx> | 2012-11-15 08:37:58 -0500 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2012-11-15 08:37:58 -0500 |
| commit | 8bb181622222f2ee3462c8b021bcae4fcdbbd37a (patch) | |
| tree | 166a1be834c8cd5a4c2521d41d7ee506bd8c8e51 /src/math/logb.c | |
| parent | 22781b4d8ecaf97ac52d2a501a2e7d3bc1920ce0 (diff) | |
| parent | 68847ecd3a644d3ffd9be58603be1a3fa437dff0 (diff) | |
| download | musl-8bb181622222f2ee3462c8b021bcae4fcdbbd37a.tar.gz musl-8bb181622222f2ee3462c8b021bcae4fcdbbd37a.tar.xz musl-8bb181622222f2ee3462c8b021bcae4fcdbbd37a.zip | |
Merge remote-tracking branch 'nsz/math'
Diffstat (limited to 'src/math/logb.c')
| -rw-r--r-- | src/math/logb.c | 17 |
1 files changed, 7 insertions, 10 deletions
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 <limits.h> #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); } |