1 files changed, 7 insertions, 0 deletions
diff --git a/src/math/logb.c b/src/math/logb.c
index d0bbfaca..8dd29371 100644
--- a/src/math/logb.c
+++ b/src/math/logb.c
@@ -1,9 +1,16 @@
 # define TGSOURCE "logb.c"
 #include "_tgmath.h"
 #include <math.h>
+#include "fenv.h"
 
 TYPE TGFN(logb)(TYPE x)
 {
+	switch (fpclassify(x)) {
+	case FP_ZERO:		feraiseexcept(FE_DIVBYZERO); return - INFINITY;
+	case FP_INFINITE:	return x;
+	default:		break;
+	}
+
 	return x;
 }