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* [Bug tree-optimization/22196] Missed back prop [not found] <bug-22196-4@http.gcc.gnu.org/bugzilla/> @ 2021-06-08 9:12 ` pinskia at gcc dot gnu.org 2023-11-07 22:25 ` pinskia at gcc dot gnu.org 2023-11-18 18:19 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-06-08 9:12 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=22196 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |ASSIGNED --- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- This actually undos some of what phi-opt might do and only should be done for a few operations. I think divide, multiple, shifts and rotates should be done and only with a constant operand. This has to be done late very close to expand even. I will be implementing this but might miss GCC 12 as I have a lot on my plate already for GCC 12. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug tree-optimization/22196] Missed back prop [not found] <bug-22196-4@http.gcc.gnu.org/bugzilla/> 2021-06-08 9:12 ` [Bug tree-optimization/22196] Missed back prop pinskia at gcc dot gnu.org @ 2023-11-07 22:25 ` pinskia at gcc dot gnu.org 2023-11-18 18:19 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu.org @ 2023-11-07 22:25 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=22196 --- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Andrew Pinski from comment #3) > This actually undos some of what phi-opt might do and only should be done > for a few operations. I think divide, multiple, shifts and rotates should > be done and only with a constant operand. This has to be done late very > close to expand even. > > I will be implementing this but might miss GCC 12 as I have a lot on my > plate already for GCC 12. It turns out this is still true. I had implemented the binary factoring out of operations for phiopt and end up with a failure with `gcc.dg/tree-prof/val-prof-1.c` which depends on phiopt not doing this. Note only one of the phi nodes needs to be constant for when we want to handle it. Oh I wonder if val-prof-1.c is still going to fail since we had originally: if (a == CST) b = CST/c; else b = a/c; And now we might have removed the if .. Woops. Anyways I will have to go and dig into that failure some more but this issue is now needed again too. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug tree-optimization/22196] Missed back prop [not found] <bug-22196-4@http.gcc.gnu.org/bugzilla/> 2021-06-08 9:12 ` [Bug tree-optimization/22196] Missed back prop pinskia at gcc dot gnu.org 2023-11-07 22:25 ` pinskia at gcc dot gnu.org @ 2023-11-18 18:19 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu.org @ 2023-11-18 18:19 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=22196 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |goon.pri.low at gmail dot com --- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> --- *** Bug 112608 has been marked as a duplicate of this bug. *** ^ permalink raw reply [flat|nested] 5+ messages in thread
[parent not found: <bug-22196-6528@http.gcc.gnu.org/bugzilla/>]
* [Bug tree-optimization/22196] Missed back prop [not found] <bug-22196-6528@http.gcc.gnu.org/bugzilla/> @ 2007-02-09 16:10 ` pinskia at gcc dot gnu dot org 0 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu dot org @ 2007-02-09 16:10 UTC (permalink / raw) To: gcc-bugs ------- Comment #2 from pinskia at gcc dot gnu dot org 2007-02-09 16:10 ------- *** Bug 30747 has been marked as a duplicate of this bug. *** -- pinskia at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |ak at muc dot de http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22196 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug tree-optimization/22196] New: Missed back prop @ 2005-06-26 20:15 pinskia at gcc dot gnu dot org 2005-07-02 17:32 ` [Bug tree-optimization/22196] " pinskia at gcc dot gnu dot org 0 siblings, 1 reply; 5+ messages in thread From: pinskia at gcc dot gnu dot org @ 2005-06-26 20:15 UTC (permalink / raw) To: gcc-bugs The following two functions should be equal: unsigned f(int i, unsigned x) { unsigned y; if (i) y = 1024; else y = 1024*1024; return x/y ; } unsigned f1(int i, unsigned x) { unsigned y; if (i) y = x/ 1024; else y = x/(1024*1024); return y ; } -- Summary: Missed back prop Product: gcc Version: 4.1.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: enhancement Priority: P2 Component: tree-optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: pinskia at gcc dot gnu dot org CC: gcc-bugs at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22196 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug tree-optimization/22196] Missed back prop 2005-06-26 20:15 [Bug tree-optimization/22196] New: " pinskia at gcc dot gnu dot org @ 2005-07-02 17:32 ` pinskia at gcc dot gnu dot org 0 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu dot org @ 2005-07-02 17:32 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From pinskia at gcc dot gnu dot org 2005-07-02 17:32 ------- Confirmed. -- What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever Confirmed| |1 Last reconfirmed|0000-00-00 00:00:00 |2005-07-02 17:32:29 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22196 ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2023-11-18 18:19 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- [not found] <bug-22196-4@http.gcc.gnu.org/bugzilla/> 2021-06-08 9:12 ` [Bug tree-optimization/22196] Missed back prop pinskia at gcc dot gnu.org 2023-11-07 22:25 ` pinskia at gcc dot gnu.org 2023-11-18 18:19 ` pinskia at gcc dot gnu.org [not found] <bug-22196-6528@http.gcc.gnu.org/bugzilla/> 2007-02-09 16:10 ` pinskia at gcc dot gnu dot org 2005-06-26 20:15 [Bug tree-optimization/22196] New: " pinskia at gcc dot gnu dot org 2005-07-02 17:32 ` [Bug tree-optimization/22196] " pinskia at gcc dot gnu dot org
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