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* [Bug rtl-optimization/33828] Issues with code hoisting implementation in gcse.c
[not found] <bug-33828-4@http.gcc.gnu.org/bugzilla/>
@ 2012-03-17 0:06 ` steven at gcc dot gnu.org
0 siblings, 0 replies; 4+ messages in thread
From: steven at gcc dot gnu.org @ 2012-03-17 0:06 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33828
Steven Bosscher <steven at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution| |FIXED
--- Comment #15 from Steven Bosscher <steven at gcc dot gnu.org> 2012-03-17 00:04:49 UTC ---
Issues mentioned here are solved (at least, sufficiently so for me).
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug rtl-optimization/33828] Issues with code hoisting implementation in gcse.c
2007-10-20 10:18 [Bug rtl-optimization/33828] New: Issues with the implementation of code hoisting " steven at gcc dot gnu dot org
2008-09-21 13:14 ` [Bug rtl-optimization/33828] Issues with code hoisting implementation " steven at gcc dot gnu dot org
2008-12-01 12:26 ` steven at gcc dot gnu dot org
@ 2010-03-25 15:28 ` steven at gcc dot gnu dot org
2 siblings, 0 replies; 4+ messages in thread
From: steven at gcc dot gnu dot org @ 2010-03-25 15:28 UTC (permalink / raw)
To: gcc-bugs
------- Comment #14 from steven at gcc dot gnu dot org 2010-03-25 15:27 -------
Add link to GIMPLE hoisting work.
--
steven at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
BugsThisDependsOn| |23286
Last reconfirmed|2007-10-29 18:59:49 |2010-03-25 15:27:46
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33828
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug rtl-optimization/33828] Issues with code hoisting implementation in gcse.c
2007-10-20 10:18 [Bug rtl-optimization/33828] New: Issues with the implementation of code hoisting " steven at gcc dot gnu dot org
2008-09-21 13:14 ` [Bug rtl-optimization/33828] Issues with code hoisting implementation " steven at gcc dot gnu dot org
@ 2008-12-01 12:26 ` steven at gcc dot gnu dot org
2010-03-25 15:28 ` steven at gcc dot gnu dot org
2 siblings, 0 replies; 4+ messages in thread
From: steven at gcc dot gnu dot org @ 2008-12-01 12:26 UTC (permalink / raw)
To: gcc-bugs
------- Comment #13 from steven at gcc dot gnu dot org 2008-12-01 12:24 -------
After fixing the issue mentioned in comment#2 and comment #8, gcse.c hoisting
hoists things too far up, e.g.:
{ pred ENTRY }
BB1
if (...) goto BB2 else goto BB3
{ succ BB2, BB3 }
{ pred BB1 }
BB2
...
goto BB4
{ succ BB4 }
{ pred BB2 }
BB3
...
goto BB4
{ succ BB4 }
{ pred BB2, BB3 }
BB4
if (...) goto BB5 else goto BB6
{ succ BB5, BB6 }
{ pred BB4 }
BB5
r1 <- exp1
goto BB7
{ succ BB7 }
{ pred BB4 }
BB6
r2 <- exp1
goto BB7
{ succ BB7 }
{ pred BB5, BB6 }
BB7
...
{ succ EXIT }
is transformed to:
{ pred ENTRY }
BB1
r3 <- exp1
if (...) goto BB2 else goto BB3
{ succ BB2, BB3 }
{ pred BB1 }
BB2
...
goto BB4
{ succ BB4 }
{ pred BB2 }
BB3
...
goto BB4
{ succ BB4 }
{ pred BB2, BB3 }
BB4
if (...) goto BB5 else goto BB6
{ succ BB5, BB6 }
{ pred BB4 }
BB5
r1 <- r3
goto BB7
{ succ BB7 }
{ pred BB4 }
BB6
r2 <- r3
goto BB7
{ succ BB7 }
{ pred BB5, BB6 }
BB7
...
{ succ EXIT }
when it would be better to hoist up only to BB4:
{ pred ENTRY }
BB1
if (...) goto BB2 else goto BB3
{ succ BB2, BB3 }
{ pred BB1 }
BB2
...
goto BB4
{ succ BB4 }
{ pred BB2 }
BB3
...
goto BB4
{ succ BB4 }
{ pred BB2, BB3 }
BB4
r3 <- exp1
if (...) goto BB5 else goto BB6
{ succ BB5, BB6 }
{ pred BB4 }
BB5
r1 <- r3
goto BB7
{ succ BB7 }
{ pred BB4 }
BB6
r2 <- r3
goto BB7
{ succ BB7 }
{ pred BB5, BB6 }
BB7
...
{ succ EXIT }
GCC should not hoist up further than up to the first common dominator.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33828
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug rtl-optimization/33828] Issues with code hoisting implementation in gcse.c
2007-10-20 10:18 [Bug rtl-optimization/33828] New: Issues with the implementation of code hoisting " steven at gcc dot gnu dot org
@ 2008-09-21 13:14 ` steven at gcc dot gnu dot org
2008-12-01 12:26 ` steven at gcc dot gnu dot org
2010-03-25 15:28 ` steven at gcc dot gnu dot org
2 siblings, 0 replies; 4+ messages in thread
From: steven at gcc dot gnu dot org @ 2008-09-21 13:14 UTC (permalink / raw)
To: gcc-bugs
------- Comment #12 from steven at gcc dot gnu dot org 2008-09-21 13:13 -------
.
--
steven at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|steven at gcc dot gnu dot |unassigned at gcc dot gnu
|org |dot org
Status|ASSIGNED |NEW
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33828
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2012-03-17 0:06 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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[not found] <bug-33828-4@http.gcc.gnu.org/bugzilla/>
2012-03-17 0:06 ` [Bug rtl-optimization/33828] Issues with code hoisting implementation in gcse.c steven at gcc dot gnu.org
2007-10-20 10:18 [Bug rtl-optimization/33828] New: Issues with the implementation of code hoisting " steven at gcc dot gnu dot org
2008-09-21 13:14 ` [Bug rtl-optimization/33828] Issues with code hoisting implementation " steven at gcc dot gnu dot org
2008-12-01 12:26 ` steven at gcc dot gnu dot org
2010-03-25 15:28 ` steven at gcc dot gnu dot org
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