1 files changed, 94 insertions, 0 deletions
diff --git a/lib/msun/src/s_rint.c b/lib/msun/src/s_rint.c
new file mode 100644
index 000000000000..5c310492b665
--- /dev/null
+++ b/lib/msun/src/s_rint.c
@@ -0,0 +1,94 @@
+/* @(#)s_rint.c 5.1 93/09/24 */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice 
+ * is preserved.
+ * ====================================================
+ */
+
+#ifndef lint
+static char rcsid[] = "$Id: s_rint.c,v 1.1.1.1 1994/05/06 00:20:07 gclarkii Exp $";
+#endif
+
+/*
+ * rint(x)
+ * Return x rounded to integral value according to the prevailing
+ * rounding mode.
+ * Method:
+ *	Using floating addition.
+ * Exception:
+ *	Inexact flag raised if x not equal to rint(x).
+ */
+
+#include "math.h"
+#include <machine/endian.h>
+
+#if BYTE_ORDER == LITTLE_ENDIAN
+#define n0	1
+#else
+#define n0	0
+#endif
+
+#ifdef __STDC__
+static const double
+#else
+static double 
+#endif
+TWO52[2]={
+  4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
+ -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */
+};
+
+#ifdef __STDC__
+	double rint(double x)
+#else
+	double rint(x)
+	double x;
+#endif
+{
+	int i0,j0,sx;
+	unsigned i,i1;
+	double w,t;
+	i0 =  *(n0+(int*)&x);
+	sx = (i0>>31)&1;
+	i1 =  *(1-n0+(int*)&x);
+	j0 = ((i0>>20)&0x7ff)-0x3ff;
+	if(j0<20) {
+	    if(j0<0) { 	
+		if(((i0&0x7fffffff)|i1)==0) return x;
+		i1 |= (i0&0x0fffff);
+		i0 &= 0xfffe0000;
+		i0 |= ((i1|-i1)>>12)&0x80000;
+		*(n0+(int*)&x)=i0;
+	        w = TWO52[sx]+x;
+	        t =  w-TWO52[sx];
+	        i0 = *(n0+(int*)&t);
+	        *(n0+(int*)&t) = (i0&0x7fffffff)|(sx<<31);
+	        return t;
+	    } else {
+		i = (0x000fffff)>>j0;
+		if(((i0&i)|i1)==0) return x; /* x is integral */
+		i>>=1;
+		if(((i0&i)|i1)!=0) {
+		    if(j0==19) i1 = 0x40000000; else
+		    i0 = (i0&(~i))|((0x20000)>>j0);
+		}
+	    }
+	} else if (j0>51) {
+	    if(j0==0x400) return x+x;	/* inf or NaN */
+	    else return x;		/* x is integral */
+	} else {
+	    i = ((unsigned)(0xffffffff))>>(j0-20);
+	    if((i1&i)==0) return x;	/* x is integral */
+	    i>>=1;
+	    if((i1&i)!=0) i1 = (i1&(~i))|((0x40000000)>>(j0-20));
+	}
+	*(n0+(int*)&x) = i0;
+	*(1-n0+(int*)&x) = i1;
+	w = TWO52[sx]+x;
+	return w-TWO52[sx];
+}