1 files changed, 16 insertions, 0 deletions
diff --git a/lib/libm/logbl.c b/lib/libm/logbl.c
new file mode 100644
index 00000000..4d7348a0
--- /dev/null
+++ b/lib/libm/logbl.c
@@ -0,0 +1,16 @@
+#include <math.h>
+#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
+long double logbl(long double x)
+{
+	return logb(x);
+}
+#else
+long double logbl(long double x)
+{
+	if (!isfinite(x))
+		return x * x;
+	if (x == 0)
+		return -1 / (x * x);
+	return ilogbl(x);
+}
+#endif