1 files changed, 27 insertions, 0 deletions
diff --git a/Python/fmod.c b/Python/fmod.c
new file mode 100644
index 0000000000..58f14f7c68
--- /dev/null
+++ b/Python/fmod.c
@@ -0,0 +1,27 @@
+/* Portable fmod(x, y) implementation for systems that don't have it */
+
+#include <math.h>
+#include <errno.h>
+
+extern int errno;
+
+double
+fmod(x, y)
+	double x, y;
+{
+	double i, f;
+	
+	if (y == 0.0) {
+		errno = EDOM;
+		return 0.0;
+	}
+	
+	/* return f such that x = i*y + f for some integer i
+	   such that |f| < |y| and f has the same sign as x */
+	
+	i = floor(x/y);
+	f = x - i*y;
+	if ((x < 0.0) != (y < 0.0))
+		f = f-y;
+	return f;
+}