Re: optimization/6864: Optimizer infinite loop/memory runaway (on gdb sources)

Re: optimization/6864: Optimizer infinite loop/memory runaway (on gdb sources)

[bangerth]

Synopsis: Optimizer infinite loop/memory runaway (on gdb sources)

State-Changed-From-To: feedback->closed
State-Changed-By: bangerth
State-Changed-When: Mon Dec  2 14:21:41 2002
State-Changed-Why:
    Submitter reports that problem most likely is fixed.
    
    Thanks for your quick feedback!

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6864

RE: optimization/6864: Optimizer infinite loop/memory runaway (on gdb sources)

[Donn Terry]

The following reply was made to PR optimization/6864; it has been noted by GNATS.

From: "Donn Terry" <donnte@microsoft.com>
To: <bangerth@dealii.org>,
	"Donn Terry" <donnte@microsoft.com>,
	<gcc-bugs@gcc.gnu.org>,
	<gcc-prs@gcc.gnu.org>,
	<nobody@gcc.gnu.org>,
	<gcc-gnats@gcc.gnu.org>
Cc:  
Subject: RE: optimization/6864: Optimizer infinite loop/memory runaway (on gdb sources)
Date: Mon, 2 Dec 2002 14:16:21 -0800

 Sorry, but I'm pretty sure it's gone at this point.  I don't even
 remember the details
 enough to tell you which gdb source file was having the problem.  I am
 pretty sure,
 however, that it got fixed along the way, as I can now compile gdb
 successfully.
 
 Donn
 
 -----Original Message-----
 From: bangerth@dealii.org [mailto:bangerth@dealii.org]=20
 Sent: Monday, December 02, 2002 1:39 PM
 To: Donn Terry; gcc-bugs@gcc.gnu.org; gcc-prs@gcc.gnu.org;
 nobody@gcc.gnu.org
 Subject: Re: optimization/6864: Optimizer infinite loop/memory runaway
 (on gdb sources)
 
 
 Synopsis: Optimizer infinite loop/memory runaway (on gdb sources)
 
 State-Changed-From-To: open->feedback
 State-Changed-By: bangerth
 State-Changed-When: Mon Dec  2 13:38:44 2002
 State-Changed-Why:
     It is unfirtunate that nobody has noticed this by now: the
     attachment to your report is missing. Do you still have it,
     so that we can attach it to the report?
    =20
     Thanks
       Wolfgang
 
 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=3Dview%20audit-trail&database=3D=
 g
 cc&pr=3D6864

Re: optimization/6864: Optimizer infinite loop/memory runaway (on gdb sources)

[bangerth]

Synopsis: Optimizer infinite loop/memory runaway (on gdb sources)

State-Changed-From-To: open->feedback
State-Changed-By: bangerth
State-Changed-When: Mon Dec  2 13:38:44 2002
State-Changed-Why:
    It is unfirtunate that nobody has noticed this by now: the
    attachment to your report is missing. Do you still have it,
    so that we can attach it to the report?
    
    Thanks
      Wolfgang

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6864

optimization/6864: Optimizer infinite loop/memory runaway (on gdb sources)

[donnte]

>Number:         6864
>Category:       optimization
>Synopsis:       Optimizer infinite loop/memory runaway (on gdb sources)
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed May 29 16:56:02 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     donnte@microsoft.com
>Release:        3.2 20020528 (experimental)
>Organization:
>Environment:
Interix.
>Description:
Goto in switch (presumably) confuses live register calculation.

Attached sample code, with marked goto (the only goto) turned on drives the compiler into an infinite loop (eating memory) at about 1145 in flow.c.  (See "while (qhead != qtail)".) Removing the goto causes the compiler to terminate normally (but of course the code is incorrect.)  The problem appeared between 5/10 and 5/28.

Sample code is somewhat stripped down from the original gdb source, removing irrelevant functions.  Both the code before the switch and (obviously) the switch body are needed to repro.  (This is all post-preprocessor, but a .c file for easy use of comments and #if for minimization.)
>How-To-Repeat:
Compile attached file, command line:
/dev/fs/C/home/donn.intel/gnu2.intel/local_bin/gcc -B/dev/fs/C/home/donn.intel/gnu2.intel/local_bin/ -c -g -O2  -D_ALL_SOURCE    -implicit -Wreturn-type -Wcomment -Wtrigraphs -Wformat -Wparentheses -Wpointer-arith -Wuninitialized  test.c -v --save-temps
>Fix:

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