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authorEric Andersen <andersen@codepoet.org>2001-06-18 08:48:15 +0000
committerEric Andersen <andersen@codepoet.org>2001-06-18 08:48:15 +0000
commit4db5f2c0a1e1a310c51bf2612a9e08dc22262b1e (patch)
tree2b3a2e17ade8acbba52955b8f8ecb1c919d744a5 /libm/double/rint.c
parente13e3a7da6efc8c81b95883e01aecd0e41142f7d (diff)
I went nuts and wrote a generic rint implementation. I think it is
correct per the man page and a little testing seems to show it works. -Erik
Diffstat (limited to 'libm/double/rint.c')
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diff --git a/libm/double/rint.c b/libm/double/rint.c
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+/* vi: set sw=4 ts=4: */
+/*
+ * rint for uClibc
+ *
+ * Copyright (C) 2001 by Lineo, inc.
+ * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Library General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <math.h>
+
+/* From the Linux man page:
+ *
+ * NAME
+ * rint - round to closest integer
+ *
+ * SYNOPSIS
+ * #include <math.h>
+ * double rint(double x);
+ *
+ * DESCRIPTION
+ * The rint() function rounds x to an integer value according
+ * to the prevalent rounding mode. The default rounding mode
+ * is to round to the nearest integer.
+ *
+ * RETURN VALUE
+ * The rint() function returns the integer value as a float­
+ * ing-point number.
+ */
+
+double rint (double x) {
+ double low = floor(x);
+ if (fmod(x,low) >= (double)0.5)
+ return(ceil(x));
+ else
+ return(low);
+}
+