Add C99's nearbyint{,f}() functions as wrappers around rint().

These trivial implementations are about 25 times slower than
rint{,f}() on x86 due to the FP environment save/restore.
They should eventually be redone in terms of fegetround() and
bit fiddling.

1 files changed, 35 insertions, 4 deletions

diff --git a/lib/msun/man/rint.3 b/lib/msun/man/rint.3
index 3af9110..09f7e19 100644
--- a/lib/msun/man/rint.3
+++ b/lib/msun/man/rint.3
@@ -32,10 +32,12 @@
 .\"     from: @(#)rint.3	5.1 (Berkeley) 5/2/91
 .\" $FreeBSD$
 .\"
-.Dd March 10, 1994
+.Dd July 5, 2004
 .Dt RINT 3
 .Os
 .Sh NAME
+.Nm nearbyint ,
+.Nm nearbyintf ,
 .Nm rint ,
 .Nm rintf
 .Nd round to integral value in floating-point format
@@ -44,6 +46,10 @@
 .Sh SYNOPSIS
 .In math.h
 .Ft double
+.Fn nearbyint "double x"
+.Ft float
+.Fn nearbyintf "float x"
+.Ft double
 .Fn rint "double x"
 .Ft float
 .Fn rintf "float x"
@@ -52,19 +58,44 @@ The
 .Fn rint
 and the
 .Fn rintf
-functions return the integral value (represented as a double or float
-precision number) nearest to
+functions return the integral value nearest to
 .Fa x
 according to the prevailing rounding mode.
+These functions raise an inexact exception when the original argument
+is not an exact integer.
+.Pp
+The
+.Fn nearbyint
+and
+.Fn nearbyintf
+functions perform the same operation, except that they do not raise
+an inexact exception.
 .Sh SEE ALSO
 .Xr abs 3 ,
 .Xr ceil 3 ,
 .Xr fabs 3 ,
+.Xr fenv 3 ,
 .Xr floor 3 ,
 .Xr ieee 3 ,
-.Xr math 3
+.Xr math 3 ,
+.Xr round 3
+.Sh STANDARDS
+The
+.Fn nearbyint ,
+.Fn nearbyintf ,
+.Fn rint ,
+and
+.Fn rintf
+functions conform to
+.St -isoC-99 .
 .Sh HISTORY
 A
 .Fn rint
 function appeared in
 .At v6 .
+The
+.Fn nearbyint
+and
+.Fn nearbyintf
+functions appeared in
+.Fx 5.3 .