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* [Bug lto/47943] New: PRE fails to move a load before a loop with LTO @ 2011-03-01 13:10 jamborm at gcc dot gnu.org 2011-03-01 13:11 ` [Bug lto/47943] " jamborm at gcc dot gnu.org ` (2 more replies) 0 siblings, 3 replies; 4+ messages in thread From: jamborm at gcc dot gnu.org @ 2011-03-01 13:10 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47943 Summary: PRE fails to move a load before a loop with LTO Product: gcc Version: 4.6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: lto AssignedTo: unassigned@gcc.gnu.org ReportedBy: jamborm@gcc.gnu.org When compiling the provided testcase with LTO, PRE fails to hoist the load of reg->node from the loop. Though this slows down the testcase only marginally, it has a substantial performance impact for 462.libquantum from SPEC 2006. When compiling the test case without LTO, PRE does move the load before the loop. Observed at least with trunk revision 170357 (2011-02-21), compiling at -Ofast with and without -flto. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug lto/47943] PRE fails to move a load before a loop with LTO 2011-03-01 13:10 [Bug lto/47943] New: PRE fails to move a load before a loop with LTO jamborm at gcc dot gnu.org @ 2011-03-01 13:11 ` jamborm at gcc dot gnu.org 2011-03-01 13:34 ` rguenth at gcc dot gnu.org 2011-03-02 0:45 ` jamborm at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: jamborm at gcc dot gnu.org @ 2011-03-01 13:11 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47943 --- Comment #1 from Martin Jambor <jamborm at gcc dot gnu.org> 2011-03-01 13:11:23 UTC --- Created attachment 23499 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23499 Testcase The testcase. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug lto/47943] PRE fails to move a load before a loop with LTO 2011-03-01 13:10 [Bug lto/47943] New: PRE fails to move a load before a loop with LTO jamborm at gcc dot gnu.org 2011-03-01 13:11 ` [Bug lto/47943] " jamborm at gcc dot gnu.org @ 2011-03-01 13:34 ` rguenth at gcc dot gnu.org 2011-03-02 0:45 ` jamborm at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: rguenth at gcc dot gnu.org @ 2011-03-01 13:34 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47943 Richard Guenther <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |WAITING Last reconfirmed| |2011.03.01 13:34:01 Ever Confirmed|0 |1 --- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-03-01 13:34:01 UTC --- I think this is a dup of PR47924 as I now get <bb 7>: pretmp.8_39 = reg_3(D)->node; pretmp.10_19 = 1 << control2_20(D); pretmp.10_42 = 1 << control1_10(D); pretmp.10_43 = pretmp.10_19 | pretmp.10_42; <bb 3>: # i_17 = PHI <i_37(10), 0(7)> ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug lto/47943] PRE fails to move a load before a loop with LTO 2011-03-01 13:10 [Bug lto/47943] New: PRE fails to move a load before a loop with LTO jamborm at gcc dot gnu.org 2011-03-01 13:11 ` [Bug lto/47943] " jamborm at gcc dot gnu.org 2011-03-01 13:34 ` rguenth at gcc dot gnu.org @ 2011-03-02 0:45 ` jamborm at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: jamborm at gcc dot gnu.org @ 2011-03-02 0:45 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47943 Martin Jambor <jamborm at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|WAITING |RESOLVED Resolution| |DUPLICATE --- Comment #3 from Martin Jambor <jamborm at gcc dot gnu.org> 2011-03-02 00:45:15 UTC --- Indeed. And libquantum is now as fast as the non-LTO one (again). Thanks. *** This bug has been marked as a duplicate of bug 47924 *** ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2011-03-02 0:45 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2011-03-01 13:10 [Bug lto/47943] New: PRE fails to move a load before a loop with LTO jamborm at gcc dot gnu.org 2011-03-01 13:11 ` [Bug lto/47943] " jamborm at gcc dot gnu.org 2011-03-01 13:34 ` rguenth at gcc dot gnu.org 2011-03-02 0:45 ` jamborm at gcc dot gnu.org
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