auto import from //depot/cupcake/@135843
diff --git a/libm/src/s_rint.c b/libm/src/s_rint.c
new file mode 100644
index 0000000..a88d7b7
--- /dev/null
+++ b/libm/src/s_rint.c
@@ -0,0 +1,87 @@
+/* @(#)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[] = "$FreeBSD: src/lib/msun/src/s_rint.c,v 1.13 2005/12/03 07:38:35 bde 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 "math_private.h"
+
+static const double
+TWO52[2]={
+ 4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
+ -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */
+};
+
+double
+rint(double x)
+{
+ int32_t i0,j0,sx;
+ u_int32_t i,i1;
+ double w,t;
+ EXTRACT_WORDS(i0,i1,x);
+ sx = (i0>>31)&1;
+ 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;
+ SET_HIGH_WORD(x,i0);
+ w = TWO52[sx]+x;
+ t = w-TWO52[sx];
+ GET_HIGH_WORD(i0,t);
+ SET_HIGH_WORD(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) {
+ /*
+ * Some bit is set after the 0.5 bit. To avoid the
+ * possibility of errors from double rounding in
+ * w = TWO52[sx]+x, adjust the 0.25 bit to a lower
+ * guard bit. We do this for all j0<=51. The
+ * adjustment is trickiest for j0==18 and j0==19
+ * since then it spans the word boundary.
+ */
+ if(j0==19) i1 = 0x40000000; else
+ if(j0==18) i1 = 0x80000000; 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 = ((u_int32_t)(0xffffffff))>>(j0-20);
+ if((i1&i)==0) return x; /* x is integral */
+ i>>=1;
+ if((i1&i)!=0) i1 = (i1&(~i))|((0x40000000)>>(j0-20));
+ }
+ INSERT_WORDS(x,i0,i1);
+ *(volatile double *)&w = TWO52[sx]+x; /* clip any extra precision */
+ return w-TWO52[sx];
+}