1 files changed, 77 insertions, 0 deletions
diff --git a/lib/msun/src/s_rintl.c b/lib/msun/src/s_rintl.c
new file mode 100644
index 0000000..21dbbf6
--- /dev/null
+++ b/lib/msun/src/s_rintl.c
@@ -0,0 +1,77 @@
+/*-
+ * Copyright (c) 2008 David Schultz <das@FreeBSD.ORG>
+ * 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, 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 <float.h>
+#include <math.h>
+
+#include "fpmath.h"
+
+static const long double
+shift[2]={
+#if LDBL_MANT_DIG == 64
+	0x1.0p63, -0x1.0p63
+#elif LDBL_MANT_DIG == 113
+	0x1.0p112, -0x1.0p112
+#else
+#error "Unsupported long double format"
+#endif
+};
+
+long double
+rintl(long double x)
+{
+	union IEEEl2bits u;
+	short sign;
+
+	u.e = x;
+
+	if (u.bits.exp >= LDBL_MANT_DIG + LDBL_MAX_EXP - 2) {
+		/*
+		 * The biased exponent is greater than the number of digits
+		 * in the mantissa, so x is inf, NaN, or an integer.
+		 */
+		if (u.bits.exp == 2 * LDBL_MAX_EXP - 1)
+			return (x + x);	/* inf or NaN */
+		else
+			return (x);
+	}
+
+	/*
+	 * The following code assumes that intermediate results are
+	 * evaluated in long double precision. If they are evaluated in
+	 * greater precision, double rounding will occur, and if they are
+	 * evaluated in less precision (as on i386), results will be
+	 * wildly incorrect.
+	 */
+	sign = u.bits.sign;
+	u.e = shift[sign] + x;
+	u.e -= shift[sign];
+	u.bits.sign = sign;
+	return (u.e);
+}