lib/42630: asin(2.0) and acos(2.0) doesn't return NaN

[naruse%airemix.jp@localhost]

>Number:         42630
>Category:       lib
>Synopsis:       asin(2.0) and acos(2.0) doesn't return NaN
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Jan 17 11:25:00 +0000 2010
>Originator:     NARUSE, Yui
>Release:        5.0.1
>Organization:
>Environment:
NetBSD kelvena 5.0.1 NetBSD 5.0.1 (GENERIC) #0: Thu Jul 30 01:39:11 UTC 2009  
builds%b8.netbsd.org@localhost:/home/builds/ab/netbsd-5-0-1-RELEASE/i386/200907292356Z-obj/home/builds/ab/netbsd-5-0-1-RELEASE/src/sys/arch/i386/compile/GENERIC
 i386
>Description:
On NetBSD 5.0.1 (i386) asin(2.0) and acos(2.0) return 0.0.
(and set errno as EDOM)

This conflicts asin's man:
 RETURN VALUES
     If |x|>1, asin(x) and asinf(x) return NaN and set the global variable
     errno to EDOM.
(acos's man doesn't descrive about return value if |x| > 1)

And lib/libm/src/e_asin.c's comment:
 * Special cases:
 *      if x is NaN, return x itself;
 *      if |x|>1, return NaN with invalid signal.
(e_acos.c also has same comment)

This seems because of the bug of lib/libm/arch/i387/e_asin.S.
(and lib/libm/arch/i387/e_acos.S)
>How-To-Repeat:
$ cat t.c
#include <stdio.h>
#include <math.h>
#include <errno.h>

int main(void)
{
  double r;
  errno = 0;
  r = asin(2.0);
  printf("r: %f isnan:%d errno:%d\n", r, isnan(r), errno);
  return 0;
}
$ cc -lm t.c
$ ./a.out
r: 0.000000 isnan:0 errno:33

>Fix: