* [Bug tree-optimization/21559] [4.1 Regression] missed jump threading
[not found] <bug-21559-6528@http.gcc.gnu.org/bugzilla/>
@ 2005-10-27 0:12 ` pinskia at gcc dot gnu dot org
2005-10-29 18:09 ` pinskia at gcc dot gnu dot org
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From: pinskia at gcc dot gnu dot org @ 2005-10-27 0:12 UTC (permalink / raw)
To: gcc-bugs
------- Comment #5 from pinskia at gcc dot gnu dot org 2005-10-27 00:12 -------
I should note that this is a true code gen regression and not just a missed one
at the tree level.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21559
^ permalink raw reply [flat|nested] 10+ messages in thread* [Bug tree-optimization/21559] [4.1 Regression] missed jump threading
[not found] <bug-21559-6528@http.gcc.gnu.org/bugzilla/>
2005-10-27 0:12 ` [Bug tree-optimization/21559] [4.1 Regression] missed jump threading pinskia at gcc dot gnu dot org
@ 2005-10-29 18:09 ` pinskia at gcc dot gnu dot org
2005-10-30 23:32 ` pinskia at gcc dot gnu dot org
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From: pinskia at gcc dot gnu dot org @ 2005-10-29 18:09 UTC (permalink / raw)
To: gcc-bugs
------- Comment #6 from pinskia at gcc dot gnu dot org 2005-10-29 18:09 -------
Another one of these I filed this bug after looking at someone else's bug for
code gen regressions.
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|4.1.0 |4.2.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21559
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[not found] <bug-21559-6528@http.gcc.gnu.org/bugzilla/>
2005-10-27 0:12 ` [Bug tree-optimization/21559] [4.1 Regression] missed jump threading pinskia at gcc dot gnu dot org
2005-10-29 18:09 ` pinskia at gcc dot gnu dot org
@ 2005-10-30 23:32 ` pinskia at gcc dot gnu dot org
2006-02-07 20:03 ` [Bug tree-optimization/21559] [4.1/4.2 " law at redhat dot com
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From: pinskia at gcc dot gnu dot org @ 2005-10-30 23:32 UTC (permalink / raw)
To: gcc-bugs
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Priority|P2 |P5
Target Milestone|4.2.0 |4.1.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21559
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[not found] <bug-21559-6528@http.gcc.gnu.org/bugzilla/>
` (2 preceding siblings ...)
2005-10-30 23:32 ` pinskia at gcc dot gnu dot org
@ 2006-02-07 20:03 ` law at redhat dot com
2006-02-28 20:38 ` mmitchel at gcc dot gnu dot org
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From: law at redhat dot com @ 2006-02-07 20:03 UTC (permalink / raw)
To: gcc-bugs
------- Comment #7 from law at redhat dot com 2006-02-07 20:03 -------
With today's changes we thread the "break" edge out of the loop. We could
still do better.
Basically we need to realize that bytes can never have the value zero when we
hit the loop test "while (toread != 0)". Once we realize that, then we'd know
that the test (if bytes == 0) has a known result on all paths reaching the
conditional.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21559
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[not found] <bug-21559-6528@http.gcc.gnu.org/bugzilla/>
` (3 preceding siblings ...)
2006-02-07 20:03 ` [Bug tree-optimization/21559] [4.1/4.2 " law at redhat dot com
@ 2006-02-28 20:38 ` mmitchel at gcc dot gnu dot org
2006-05-25 2:45 ` mmitchel at gcc dot gnu dot org
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From: mmitchel at gcc dot gnu dot org @ 2006-02-28 20:38 UTC (permalink / raw)
To: gcc-bugs
--
mmitchel at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|4.1.0 |4.1.1
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21559
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[not found] <bug-21559-6528@http.gcc.gnu.org/bugzilla/>
` (4 preceding siblings ...)
2006-02-28 20:38 ` mmitchel at gcc dot gnu dot org
@ 2006-05-25 2:45 ` mmitchel at gcc dot gnu dot org
2007-02-14 9:37 ` [Bug tree-optimization/21559] [4.1/4.2/4.3 " mmitchel at gcc dot gnu dot org
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From: mmitchel at gcc dot gnu dot org @ 2006-05-25 2:45 UTC (permalink / raw)
To: gcc-bugs
------- Comment #8 from mmitchel at gcc dot gnu dot org 2006-05-25 02:36 -------
Will not be fixed in 4.1.1; adjust target milestone to 4.1.2.
--
mmitchel at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|4.1.1 |4.1.2
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21559
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[not found] <bug-21559-6528@http.gcc.gnu.org/bugzilla/>
` (5 preceding siblings ...)
2006-05-25 2:45 ` mmitchel at gcc dot gnu dot org
@ 2007-02-14 9:37 ` mmitchel at gcc dot gnu dot org
2008-07-04 16:53 ` [Bug tree-optimization/21559] [4.2/4.3/4.4 " jsm28 at gcc dot gnu dot org
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From: mmitchel at gcc dot gnu dot org @ 2007-02-14 9:37 UTC (permalink / raw)
To: gcc-bugs
--
mmitchel at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|4.1.2 |4.1.3
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21559
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[not found] <bug-21559-6528@http.gcc.gnu.org/bugzilla/>
` (6 preceding siblings ...)
2007-02-14 9:37 ` [Bug tree-optimization/21559] [4.1/4.2/4.3 " mmitchel at gcc dot gnu dot org
@ 2008-07-04 16:53 ` jsm28 at gcc dot gnu dot org
2008-11-22 11:37 ` steven at gcc dot gnu dot org
2008-11-22 15:48 ` [Bug tree-optimization/21559] [4.2/4.3 " rguenth at gcc dot gnu dot org
9 siblings, 0 replies; 10+ messages in thread
From: jsm28 at gcc dot gnu dot org @ 2008-07-04 16:53 UTC (permalink / raw)
To: gcc-bugs
------- Comment #9 from jsm28 at gcc dot gnu dot org 2008-07-04 16:53 -------
Closing 4.1 branch.
--
jsm28 at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|[4.1/4.2/4.3/4.4 Regression]|[4.2/4.3/4.4 Regression]
|missed jump threading |missed jump threading
Target Milestone|4.1.3 |4.2.5
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21559
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[not found] <bug-21559-6528@http.gcc.gnu.org/bugzilla/>
` (7 preceding siblings ...)
2008-07-04 16:53 ` [Bug tree-optimization/21559] [4.2/4.3/4.4 " jsm28 at gcc dot gnu dot org
@ 2008-11-22 11:37 ` steven at gcc dot gnu dot org
2008-11-22 15:48 ` [Bug tree-optimization/21559] [4.2/4.3 " rguenth at gcc dot gnu dot org
9 siblings, 0 replies; 10+ messages in thread
From: steven at gcc dot gnu dot org @ 2008-11-22 11:37 UTC (permalink / raw)
To: gcc-bugs
------- Comment #10 from steven at gcc dot gnu dot org 2008-11-22 11:36 -------
Trunk today generates the following code (this is the final_cleanup dump):
;; Function foo (foo)
foo ()
{
static char eof_reached = 0;
int bytes;
int toread;
<bb 2>:
toread = 4096;
<bb 3>:
bytes = bar (toread);
if (bytes <= 0)
goto <bb 4>;
else
goto <bb 5>;
<bb 4>:
if (bytes != 0)
goto <bb 6>;
else
goto <bb 7>;
<bb 5>:
toread = toread - bytes;
<bb 6>:
if (toread != 0)
goto <bb 3>;
else
goto <bb 8>;
<bb 7>:
eof_reached = 1;
<bb 8>:
return;
}
Looks like we can't do any better than that -- can we??
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21559
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[not found] <bug-21559-6528@http.gcc.gnu.org/bugzilla/>
` (8 preceding siblings ...)
2008-11-22 11:37 ` steven at gcc dot gnu dot org
@ 2008-11-22 15:48 ` rguenth at gcc dot gnu dot org
9 siblings, 0 replies; 10+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2008-11-22 15:48 UTC (permalink / raw)
To: gcc-bugs
------- Comment #11 from rguenth at gcc dot gnu dot org 2008-11-22 15:47 -------
I don't see how. Fixed thus, WONTFIX on the branches.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Known to fail|4.3.0 4.2.0 |4.3.2 4.2.4
Resolution| |FIXED
Target Milestone|4.2.5 |4.4.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21559
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