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* Re: optimization/6713: Regression wrt 3.0.4: g++ -O2 leads to seg fault at run time
@ 2002-05-22 19:36 Glen Nakamura
0 siblings, 0 replies; 3+ messages in thread
From: Glen Nakamura @ 2002-05-22 19:36 UTC (permalink / raw)
To: nobody; +Cc: gcc-prs
The following reply was made to PR optimization/6713; it has been noted by GNATS.
From: Glen Nakamura <glen@imodulo.com>
To: gcc-gnats@gcc.gnu.org, mark@ecriticalinc.com, pcarlini@unitus.it,
gcc-bugs@gcc.gnu.org, nobody@gcc.gnu.org
Cc:
Subject: Re: optimization/6713: Regression wrt 3.0.4: g++ -O2 leads to seg fault at run time
Date: Wed, 22 May 2002 16:31:39 -1000
http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6713
FYI: the problem also goes away when compiling w/ -O2 -fno-strength-reduce.
I'm not sure how it's supposed to work, but strength_reduce() in loop.c
eliminates reg 60 but leaves a REG_EQUAL note referring to it within the loop.
I think this REG_EQUAL note is cause of the problem... If I eliminate it,
the problem goes away. BTW, changing ++i to i++ in the for loop avoids the
problem since the REG_EQUAL note is not emitted in that case.
Any thoughts on how to fix this? I'm not familiar enough with the loop
optimizer to produce a proper patch.
- Glen Nakamura
[snip]
giv at 482 reduced to (reg 135)
giv at 480 reduced to (reg 135)
biv 60 was eliminated.
Reg 60: biv eliminated
[snip]
(note 351 591 492 NOTE_INSN_LOOP_BEG)
[snip]
(note 529 474 482 [bb 6] NOTE_INSN_BASIC_BLOCK)
(insn 482 529 588 (set (reg/s/f:SI 111)
(reg/f:SI 135)) -1 (nil)
(expr_list:REG_EQUAL (plus:SI (reg/v:SI 60) <<< PROBLEM NOTE???
(const_int 1 [0x1]))
(nil)))
(insn 588 482 489 (set (reg/s/f:SI 111)
(reg/f:SI 135)) -1 (nil)
(nil))
(note 489 588 490 0x40660980 NOTE_INSN_BLOCK_END)
[snip]
(note 497 408 499 NOTE_INSN_LOOP_END)
[snip]
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: optimization/6713: Regression wrt 3.0.4: g++ -O2 leads to seg fault at run time
@ 2002-09-04 8:54 paolo
0 siblings, 0 replies; 3+ messages in thread
From: paolo @ 2002-09-04 8:54 UTC (permalink / raw)
To: gcc-bugs, gcc-prs, mark, nobody, pcarlini
Synopsis: Regression wrt 3.0.4: g++ -O2 leads to seg fault at run time
State-Changed-From-To: open->closed
State-Changed-By: paolo
State-Changed-When: Wed Sep 4 08:54:44 2002
State-Changed-Why:
Fixed by rth.
http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6713
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: optimization/6713: Regression wrt 3.0.4: g++ -O2 leads to seg fault at run time
@ 2002-05-18 2:26 Paolo Carlini
0 siblings, 0 replies; 3+ messages in thread
From: Paolo Carlini @ 2002-05-18 2:26 UTC (permalink / raw)
To: nobody; +Cc: gcc-prs
The following reply was made to PR optimization/6713; it has been noted by GNATS.
From: Paolo Carlini <pcarlini@unitus.it>
To: gcc-gnats@gcc.gnu.org, gcc-prs@gcc.gnu.org, mark@ecriticalinc.com,
pcarlini@unitus.it, gcc-bugs@gcc.gnu.org
Cc:
Subject: Re: optimization/6713: Regression wrt 3.0.4: g++ -O2 leads to seg
fault at run time
Date: Sat, 18 May 2002 11:23:20 +0200
An additional bit of information: the problem also goes away with -O2
-fno-inline, therefore it definitely seems inlining related.
Ciao, Paolo.
http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6713
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2002-09-04 15:54 UTC | newest]
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2002-05-22 19:36 optimization/6713: Regression wrt 3.0.4: g++ -O2 leads to seg fault at run time Glen Nakamura
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2002-09-04 8:54 paolo
2002-05-18 2:26 Paolo Carlini
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