Add round(3) and roundf(3) and the associated documentation.

PR:		59797
Submitted by:	"Steven G. Kargl" <kargl@troutmask.apl.washington.edu>
Reviewed by:	bde (earlier version, last year)

1 files changed, 53 insertions, 0 deletions

diff --git a/lib/msun/src/s_round.c b/lib/msun/src/s_round.c
new file mode 100644
index 0000000..ea764ae
--- /dev/null
+++ b/lib/msun/src/s_round.c
@@ -0,0 +1,53 @@
+/*-
+ * Copyright (c) 2003, Steven G. Kargl
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice unmodified, this list of conditions, and the following
+ *    disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <math.h>
+
+double
+round(double x)
+{
+	double t;
+	int i;
+
+	i = fpclassify(x);
+	if (i == FP_INFINITE || i == FP_NAN)
+		return (x);
+
+	if (x >= 0.0) {
+		t = ceil(x);
+		if (t - x > 0.5)
+			t -= 1.0;
+		return (t);
+	} else {
+		t = ceil(-x);
+		if (t + x > 0.5)
+			t -= 1.0;
+		return (-t);
+	}
+}