Re: optimization/6411: Division by zero may not raise exception on Linux/X86

Re: optimization/6411: Division by zero may not raise exception on Linux/X86

[rth]

Synopsis: Division by zero may not raise exception on Linux/X86

State-Changed-From-To: open->closed
State-Changed-By: rth
State-Changed-When: Mon Oct  7 00:15:20 2002
State-Changed-Why:
    Fixed.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6411

Re: optimization/6411: Division by zero may not raise exception on Linux/X86

[Andrew Pinski]

The following reply was made to PR optimization/6411; it has been noted by GNATS.

From: Andrew Pinski <pinskia@physics.uc.edu>
To: Hans_Boehm@hp.com, gcc-gnats@gcc.gnu.org, gcc-prs@gcc.gnu.org,
   tromey@redhat.com, gcc-bugs@gcc.gnu.org, nobody@gcc.gnu.org
Cc:  
Subject: Re: optimization/6411: Division by zero may not raise exception on Linux/X86
Date: Sun, 6 Oct 2002 21:32:54 -0700

 This has been at least been fixed for 3.3(gcc version 3.3 20021003  
 (experimental)).
 
 Thanks,
 Andrew Pinski
 PS Just looking through the bug database and bugs I have marked I  
 wanted to try to fix.
 
 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit- 
 trail&database=gcc&pr=6411
 

optimization/6411: Division by zero may not raise exception on Linux/X86

[Hans_Boehm]

>Number:         6411
>Category:       optimization
>Synopsis:       Division by zero may not raise exception on Linux/X86
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Apr 22 15:36:01 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     Hans_Boehm@hp.com
>Release:        Gcc pre3.1
>Organization:
>Environment:
Linux/X86
>Description:
A division by zero can be eliminated by the gcc optimizer.
This is incorrect for Java code, since it should still 
raise an exception.  This causes SPECjbb, for example,
to fail with gcj on X86.

This doesn't seem to be an issue on IA64, probably because
a divide routine is always called?
>How-To-Repeat:
[hboehm@hoh ~/java]$ cat divtest2.java
public class divtest2 {
    public static void main(String argv[])
    {
	int a = -10;
	int b = 0;
	try {
	  a = a/b;
	  System.out.println("Failed to throw it");
	} catch (java.lang.Exception x) {
	  System.out.println("Caught it");
	}
    }
}
[hboehm@hoh ~/java]$ gcj divtest2.java --main=divtest2
[hboehm@hoh ~/java]$ ./a.out
Caught it
[hboehm@hoh ~/java]$ gcj -O2 divtest2.java --main=divtest2
[hboehm@hoh ~/java]$ ./a.out
Failed to throw it
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: