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* Re: middle-end/6566: sparc64-unknown-netbsd-gcc loops consuming memory
@ 2003-04-06 13:14 hubicka
0 siblings, 0 replies; 3+ messages in thread
From: hubicka @ 2003-04-06 13:14 UTC (permalink / raw)
To: gcc-bugs, gcc-prs, hubicka, thorpej
Synopsis: sparc64-unknown-netbsd-gcc loops consuming memory
State-Changed-From-To: analyzed->closed
State-Changed-By: hubicka
State-Changed-When: Sun Apr 6 13:14:30 2003
State-Changed-Why:
This has been fixed a while ago by Richard
http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6566
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: middle-end/6566: sparc64-unknown-netbsd-gcc loops consuming memory
@ 2002-06-07 4:26 Jan Hubicka
0 siblings, 0 replies; 3+ messages in thread
From: Jan Hubicka @ 2002-06-07 4:26 UTC (permalink / raw)
To: hubicka; +Cc: gcc-prs
The following reply was made to PR middle-end/6566; it has been noted by GNATS.
From: Jan Hubicka <jh@suse.cz>
To: davem@gcc.gnu.org, gcc-bugs@gcc.gnu.org, gcc-prs@gcc.gnu.org,
hubicka@gcc.gnu.org, nobody@gcc.gnu.org, thorpej@wasabisystems.com,
gcc-gnats@gcc.gnu.org
Cc:
Subject: Re: middle-end/6566: sparc64-unknown-netbsd-gcc loops consuming memory
Date: Fri, 7 Jun 2002 13:22:22 +0200
> Synopsis: sparc64-unknown-netbsd-gcc loops consuming memory
>
> Responsible-Changed-From-To: unassigned->hubicka
> Responsible-Changed-By: davem
> Responsible-Changed-When: Fri Jun 7 01:32:16 2002
> Responsible-Changed-Why:
> Jan can you take a look at this? The problem is
> calculate_global_regs_live() is what is looping.
> Every iteration, right before qhead gets to qtail
> in the main loop, we advance qtail almost through
> the whole queue. This process repeats forever.
> Any target crossed to sparc64-netbsd will be able
> to reproduce this so it should be easy for you to
> work on it.
> Thanks.
> State-Changed-From-To: open->analyzed
> State-Changed-By: davem
> State-Changed-When: Fri Jun 7 01:32:16 2002
> State-Changed-Why:
> calculate_global_regs_live loops forever never making
> forward progress
This has been discussed on the list briefly. The problem is that
iterative dataflow is not guaranteed to terminate when the starting
sollution is not strictly bellow the correct one.
We commonly do that and situation got worse after the renumbering
changes, but really it just makes latent bug to happen more often.
I want to take a look at it today or tomorrow. My plan is to turn
dataflow into hybrid search, as df.c does, so we save some bits and
create extra bitmap for each basic block noting changes in the liveness.
When we change liveness of given pseudo twice, we wipe all the liveness
bits of it and re-start relaxation.
Not perfect sollution, but should work in practice. I am still looking
for hints in the literatue, but most of it does appear to suggest that
inverval analysis is the proper way to go.
Honza
>
> http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6566
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: middle-end/6566: sparc64-unknown-netbsd-gcc loops consuming memory
@ 2002-06-07 1:32 davem
0 siblings, 0 replies; 3+ messages in thread
From: davem @ 2002-06-07 1:32 UTC (permalink / raw)
To: gcc-bugs, gcc-prs, hubicka, nobody, thorpej
Synopsis: sparc64-unknown-netbsd-gcc loops consuming memory
Responsible-Changed-From-To: unassigned->hubicka
Responsible-Changed-By: davem
Responsible-Changed-When: Fri Jun 7 01:32:16 2002
Responsible-Changed-Why:
Jan can you take a look at this? The problem is
calculate_global_regs_live() is what is looping.
Every iteration, right before qhead gets to qtail
in the main loop, we advance qtail almost through
the whole queue. This process repeats forever.
Any target crossed to sparc64-netbsd will be able
to reproduce this so it should be easy for you to
work on it.
Thanks.
State-Changed-From-To: open->analyzed
State-Changed-By: davem
State-Changed-When: Fri Jun 7 01:32:16 2002
State-Changed-Why:
calculate_global_regs_live loops forever never making
forward progress
http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6566
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2003-04-06 13:14 UTC | newest]
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2003-04-06 13:14 middle-end/6566: sparc64-unknown-netbsd-gcc loops consuming memory hubicka
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2002-06-07 4:26 Jan Hubicka
2002-06-07 1:32 davem
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