Re: port-alpha/48782 (# top [1] Floating point exception (core dumped) top)

["Naruaki.Etomi" <nullnilaki%gmail.com@localhost>]

The following reply was made to PR port-alpha/48782; it has been noted by GNATS.

From: "Naruaki.Etomi" <nullnilaki%gmail.com@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: martin%netbsd.org@localhost, port-alpha-maintainer%netbsd.org@localhost
Subject: Re: port-alpha/48782 (# top [1] Floating point exception (core
 dumped) top)
Date: Wed, 21 May 2014 02:14:22 +0900

 Dear martin,
 
 I carry out a test on current version.
 (__KERNEL_RCSID(0, "$NetBSD: fp_complete.c,v 1.21 2014/05/19 07:09:10
 matt Exp $");)
 
 $ uname -a
 NetBSD  6.99.42 NetBSD 6.99.42 (GENERIC-$Revision: 1.358 $) #0: Tue
 May 20 12:29:46 UTC 2014
 naruaki@:/usr/obj.alpha/sys/arch/alpha/compile/GENERIC alpha
 
 NaN
 --------------------
 #include<stdio.h>
 #include <math.h>
 
 int main(void){
         double a, b;
         a = 0.0 / 0.0;
         printf("a=%lf isnan=%d\n", a, isnan(a));
         b = 1.0 + a;
         printf("b=%lf\n", b);
         return 0;
 }
 
 NetBSD
 ----------
 $ gcc -mieee-with-inexact -lm test1.c
 
 $ ./a.out
 a=nan isnan=1
 b=nan
 
 Tru64 UNIX
 ----------
 ds15> cc -ieee_with_inexact -lm test1.c
 cc: Warning: test1.c, line 6: In this statement, floating-point
 overflow occurs in evaluating the expression "0.0/0.0". (floatoverfl)
 a = 0.0 / 0.0;
 ----^
 ds15> ./a.out
 a=NaNQ isnan=1
 b=NaNQ
 --------------------
 
 Infinity
 --------------------
 #include <stdio.h>
 #include <math.h>
 
 int main(void){
         double a, b;
         a = 1.0 / 0.0;
         printf("a=%lf isinf=%d\n", a, isinf(a));
         b = 1.0 / a;
         printf("b=%lf\n", b);
         return 0;
 }
 
 NetBSD
 ----------
 $ gcc -mieee-with-inexact  -lm test2.c
 
 $ ./a.out
 a=inf isinf=1
 b=0.000000
 
 Tru64 UNIX
 ----------
 Tru64 UNIX is not implemented isinf()
 --------------------
 
 Signed zero
 --------------------
 #include <stdio.h>
 #include <math.h>
 
 int main(void){
         double a, b, c, d;
         a = 1.0 / 0.0;
         b = -1.0 / 0.0;
         printf("a=%lf b=%lf\n", a, b);
         c = 1.0 / a;
         d = 1.0 / b;
         printf("c = %lf d = %lf\n", c, d);
         printf("ans1=%lf, and2=%lf\n", 1.0 / c, 1.0 / d);
         return 0;
 }
 
 NetBSD
 ----------
 $ gcc -mieee-with-inexact  -lm test3.c
 
 $ ./a.out
 a=inf b=-inf
 c = 0.000000 d = -0.000000
 ans1=inf, and2=-inf
 
 Tru64 UNIX
 ----------
 ds15> cc -ieee_with_inexact -lm test3.c
 cc: Warning: test3.c, line 6: In this statement, division by zero
 occurs in evaluating the expression "1.0/0.0". (zerodiv)
 a = 1.0 / 0.0;
 ----^
 cc: Warning: test3.c, line 7: In this statement, division by zero
 occurs in evaluating the expression "-1.0/0.0". (zerodiv)
 b = -1.0 / 0.0;
 ----^
 ds15> ./a.out
 a=INF b=-INF
 c = 0.000000 d = -0.000000
 ans1=INF, and2=-INF
 --------------------
 
 I think that the problem was solved.
 Your work is wonderful!
 
 Of course, Userland application(e.g., /pkgsrc/net/mikutter) work fine!
 https://twitter.com/nullnilaki/status/468744417319206912/photo/1
 
 That's very nice of you!
 --
 Naruaki Etomi / nullnilaki%gmail.com@localhost