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* [Bug rtl-optimization/29854] New: reload_combine looses track of uses
@ 2006-11-15 21:12 amylaar at gcc dot gnu dot org
2008-12-26 16:04 ` [Bug rtl-optimization/29854] " tkoenig at gcc dot gnu dot org
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: amylaar at gcc dot gnu dot org @ 2006-11-15 21:12 UTC (permalink / raw)
To: gcc-bugs
When reload_combine replaces a register with a sum of
another register ('base') and a constant, it fails to
note the new uses of the base. Thus, when it later
replaces the base, thew new uses won't be updated.
A patch is here:
http://gcc.gnu.org/ml/gcc-patches/2006-01/msg01387.html
--
Summary: reload_combine looses track of uses
Product: gcc
Version: 4.3.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: rtl-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: amylaar at gcc dot gnu dot org
OtherBugsDependingO 29842
nThis:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29854
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug rtl-optimization/29854] reload_combine looses track of uses
2006-11-15 21:12 [Bug rtl-optimization/29854] New: reload_combine looses track of uses amylaar at gcc dot gnu dot org
@ 2008-12-26 16:04 ` tkoenig at gcc dot gnu dot org
2008-12-27 12:18 ` amylaar at gcc dot gnu dot org
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: tkoenig at gcc dot gnu dot org @ 2008-12-26 16:04 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from tkoenig at gcc dot gnu dot org 2008-12-26 16:02 -------
Is there a test case which shows the wrong-code
behavior, and which can be checked against the
new register allocator?
--
tkoenig at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |WAITING
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29854
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug rtl-optimization/29854] reload_combine looses track of uses
2006-11-15 21:12 [Bug rtl-optimization/29854] New: reload_combine looses track of uses amylaar at gcc dot gnu dot org
2008-12-26 16:04 ` [Bug rtl-optimization/29854] " tkoenig at gcc dot gnu dot org
@ 2008-12-27 12:18 ` amylaar at gcc dot gnu dot org
2008-12-28 16:50 ` tkoenig at gcc dot gnu dot org
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: amylaar at gcc dot gnu dot org @ 2008-12-27 12:18 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from amylaar at gcc dot gnu dot org 2008-12-27 12:16 -------
(In reply to comment #1)
> Is there a test case which shows the wrong-code
> behavior, and which can be checked against the
> new register allocator?
I don't know of any particular test case. If you
want one, I suggest to compile the SH linux kernel
with and without the patch and diff the assemply
output of the compiler.
You could also try looking in Toshi Morita's
stress testsuite, or any other code that is heavy
with reloads and large stack frames.
--
amylaar at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|WAITING |NEW
Ever Confirmed|0 |1
Last reconfirmed|0000-00-00 00:00:00 |2008-12-27 12:16:47
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29854
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug rtl-optimization/29854] reload_combine looses track of uses
2006-11-15 21:12 [Bug rtl-optimization/29854] New: reload_combine looses track of uses amylaar at gcc dot gnu dot org
2008-12-26 16:04 ` [Bug rtl-optimization/29854] " tkoenig at gcc dot gnu dot org
2008-12-27 12:18 ` amylaar at gcc dot gnu dot org
@ 2008-12-28 16:50 ` tkoenig at gcc dot gnu dot org
2008-12-28 22:08 ` amylaar at gcc dot gnu dot org
2009-12-16 17:27 ` tkoenig at gcc dot gnu dot org
4 siblings, 0 replies; 6+ messages in thread
From: tkoenig at gcc dot gnu dot org @ 2008-12-28 16:50 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from tkoenig at gcc dot gnu dot org 2008-12-28 16:44 -------
Is this still an issue with current trunk, or
with 4.3?
If that's the case, please add a test case,
with preprocessed source (even if it is very large)
showing the problem.
--
tkoenig at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |WAITING
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29854
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug rtl-optimization/29854] reload_combine looses track of uses
2006-11-15 21:12 [Bug rtl-optimization/29854] New: reload_combine looses track of uses amylaar at gcc dot gnu dot org
` (2 preceding siblings ...)
2008-12-28 16:50 ` tkoenig at gcc dot gnu dot org
@ 2008-12-28 22:08 ` amylaar at gcc dot gnu dot org
2009-12-16 17:27 ` tkoenig at gcc dot gnu dot org
4 siblings, 0 replies; 6+ messages in thread
From: amylaar at gcc dot gnu dot org @ 2008-12-28 22:08 UTC (permalink / raw)
To: gcc-bugs
------- Comment #4 from amylaar at gcc dot gnu dot org 2008-12-28 22:07 -------
(In reply to comment #3)
> Is this still an issue with current trunk, or
> with 4.3?
I had a look at the current trunk and the diffs leading up to it, and I can
confirm that the issue has not been fixed.
However, I don't have any specific test case.
Note also that for this kind of bug you can expect test cases to be
- very large and hard to understand
- appearing and disappearing in a pseudo-random manner as you make prima facie
unrelated changes to other passes.
- For the trunk, or any branch with significant activity, it is likely that
it takes longer to find a testcase than it takes that testcase to become
obsolete because of some new check-in.
--
amylaar at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|WAITING |NEW
Last reconfirmed|2008-12-27 12:16:47 |2008-12-28 22:07:33
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29854
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug rtl-optimization/29854] reload_combine looses track of uses
2006-11-15 21:12 [Bug rtl-optimization/29854] New: reload_combine looses track of uses amylaar at gcc dot gnu dot org
` (3 preceding siblings ...)
2008-12-28 22:08 ` amylaar at gcc dot gnu dot org
@ 2009-12-16 17:27 ` tkoenig at gcc dot gnu dot org
4 siblings, 0 replies; 6+ messages in thread
From: tkoenig at gcc dot gnu dot org @ 2009-12-16 17:27 UTC (permalink / raw)
To: gcc-bugs
------- Comment #5 from tkoenig at gcc dot gnu dot org 2009-12-16 17:27 -------
A test case is still required.
--
tkoenig at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |WAITING
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29854
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2009-12-16 17:27 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2006-11-15 21:12 [Bug rtl-optimization/29854] New: reload_combine looses track of uses amylaar at gcc dot gnu dot org
2008-12-26 16:04 ` [Bug rtl-optimization/29854] " tkoenig at gcc dot gnu dot org
2008-12-27 12:18 ` amylaar at gcc dot gnu dot org
2008-12-28 16:50 ` tkoenig at gcc dot gnu dot org
2008-12-28 22:08 ` amylaar at gcc dot gnu dot org
2009-12-16 17:27 ` tkoenig at gcc dot gnu dot org
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