1 files changed, 40 insertions, 0 deletions

diff --git a/lib/libF77/r_mod.c b/lib/libF77/r_mod.c
new file mode 100644
index 000000000000..7adb44cdbec0
--- /dev/null
+++ b/lib/libF77/r_mod.c
@@ -0,0 +1,40 @@
+#include "f2c.h"
+
+#ifdef KR_headers
+#ifdef IEEE_drem
+double drem();
+#else
+double floor();
+#endif
+double r_mod(x,y) real *x, *y;
+#else
+#ifdef IEEE_drem
+double drem(double, double);
+#else
+#undef abs
+#include "math.h"
+#endif
+double r_mod(real *x, real *y)
+#endif
+{
+#ifdef IEEE_drem
+	double xa, ya, z;
+	if ((ya = *y) < 0.)
+		ya = -ya;
+	z = drem(xa = *x, ya);
+	if (xa > 0) {
+		if (z < 0)
+			z += ya;
+		}
+	else if (z > 0)
+		z -= ya;
+	return z;
+#else
+	double quotient;
+	if( (quotient = (double)*x / *y) >= 0)
+		quotient = floor(quotient);
+	else
+		quotient = -floor(-quotient);
+	return(*x - (*y) * quotient );
+#endif
+}