1 files changed, 70 insertions, 0 deletions
diff --git a/libm/double/round.c b/libm/double/round.c
new file mode 100644
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+++ b/libm/double/round.c
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+/*							round.c
+ *
+ *	Round double to nearest or even integer valued double
+ *
+ *
+ *
+ * SYNOPSIS:
+ *
+ * double x, y, round();
+ *
+ * y = round(x);
+ *
+ *
+ *
+ * DESCRIPTION:
+ *
+ * Returns the nearest integer to x as a double precision
+ * floating point result.  If x ends in 0.5 exactly, the
+ * nearest even integer is chosen.
+ * 
+ *
+ *
+ * ACCURACY:
+ *
+ * If x is greater than 1/(2*MACHEP), its closest machine
+ * representation is already an integer, so rounding does
+ * not change it.
+ */
+
+/*
+Cephes Math Library Release 2.1:  January, 1989
+Copyright 1984, 1987, 1989 by Stephen L. Moshier
+Direct inquiries to 30 Frost Street, Cambridge, MA 02140
+*/
+#include <math.h>
+#ifdef ANSIPROT
+double floor ( double );
+#else
+double floor();
+#endif
+
+double round(x)
+double x;
+{
+double y, r;
+
+/* Largest integer <= x */
+y = floor(x);
+
+/* Fractional part */
+r = x - y;
+
+/* Round up to nearest. */
+if( r > 0.5 )
+	goto rndup;
+
+/* Round to even */
+if( r == 0.5 )
+	{
+	r = y - 2.0 * floor( 0.5 * y );
+	if( r == 1.0 )
+		{
+rndup:
+		y += 1.0;
+		}
+	}
+
+/* Else round down. */
+return(y);
+}