first commit of the new libm!

[musl] / src / math / roundf.c

diff --git a/src/math/roundf.c b/src/math/roundf.c
new file mode 100644 (file)
index 0000000..3cfd8ae
--- /dev/null
+++ b/src/math/roundf.c
@@ -0,0 +1,48 @@
+/* origin: FreeBSD /usr/src/lib/msun/src/s_roundf.c */
+/*-
+ * 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 "libm.h"
+
+float roundf(float x)
+{
+       float t;
+
+       if (!isfinite(x))
+               return x;
+
+       if (x >= 0.0) {
+               t = floorf(x);
+               if (t - x <= -0.5)
+                       t += 1.0;
+               return t;
+       } else {
+               t = floorf(-x);
+               if (t + x <= -0.5)
+                       t += 1.0;
+               return -t;
+       }
+}