1 files changed, 12 insertions, 0 deletions
diff --git a/src/math/signbit.c b/src/math/signbit.c
new file mode 100644
index 00000000..7b5ba8a2
--- /dev/null
+++ b/src/math/signbit.c
@@ -0,0 +1,12 @@
+#include <math.h>
+                               int __signbitf(float x);
+                              int __signbitd(double x);
+                         int __signbitl(long double x);
+
+#define signbit(x)          ((sizeof (x) == sizeof (float)) ? __signbitf(x) : \
+                (sizeof (x) == sizeof (double)) ? __signbitd(x) : __signbitl(x))
+
+/*
+STDC(199901)
+LINK(m)
+*/