1 files changed, 16 insertions, 0 deletions
diff --git a/missing/isnan.c b/missing/isnan.c
new file mode 100644
index 0000000000..96bb93ba6a
--- /dev/null
+++ b/missing/isnan.c
@@ -0,0 +1,16 @@
+static int double_ne();
+
+int
+isnan(n)
+  double n;
+{
+  return double_ne(n, n);
+}
+
+static
+int
+double_ne(n1, n2)
+  double n1, n2;
+{
+  return n1 != n2;
+}