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* [Bug tree-optimization/21829] New: [4.1 Regression] missed jump threading after unroller @ 2005-05-30 19:06 pinskia at gcc dot gnu dot org 2005-05-30 19:21 ` [Bug tree-optimization/21829] " pinskia at gcc dot gnu dot org ` (2 more replies) 0 siblings, 3 replies; 6+ messages in thread From: pinskia at gcc dot gnu dot org @ 2005-05-30 19:06 UTC (permalink / raw) To: gcc-bugs Take the following code: int test(int v) { int x = 0; for (int u=0;u<2;u++) { if (u>v) // v is input-arg the compiler can't deside at compiletime { if (u%2==1) // can only happen for u==1 (so loops for 0 and 2 does not do x++; // anything. Hoped gcc would notice when unrolling. } } return x; } We get: <bb 0>: if (v_8 < 0) goto <L1>; else goto <L15>; <L15>:; if (v_8 <= 0) goto <L1>; else goto <L3>; <L1>:; # x_1 = PHI <0(3), 1(1)>; <L3>:; return x_1; } Notice that the if in L15 is always true. The 4.0 branch gets this correct. -- Summary: [4.1 Regression] missed jump threading after unroller Product: gcc Version: 4.0.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: minor 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=21829 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/21829] [4.1 Regression] missed jump threading after unroller 2005-05-30 19:06 [Bug tree-optimization/21829] New: [4.1 Regression] missed jump threading after unroller pinskia at gcc dot gnu dot org @ 2005-05-30 19:21 ` pinskia at gcc dot gnu dot org 2005-06-12 3:44 ` pinskia at gcc dot gnu dot org 2005-09-10 5:56 ` pinskia at gcc dot gnu dot org 2 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu dot org @ 2005-05-30 19:21 UTC (permalink / raw) To: gcc-bugs -- What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|--- |4.1.0 Version|4.0.0 |4.1.0 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21829 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/21829] [4.1 Regression] missed jump threading after unroller 2005-05-30 19:06 [Bug tree-optimization/21829] New: [4.1 Regression] missed jump threading after unroller pinskia at gcc dot gnu dot org 2005-05-30 19:21 ` [Bug tree-optimization/21829] " pinskia at gcc dot gnu dot org @ 2005-06-12 3:44 ` pinskia at gcc dot gnu dot org 2005-09-10 5:56 ` pinskia at gcc dot gnu dot org 2 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu dot org @ 2005-06-12 3:44 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From pinskia at gcc dot gnu dot org 2005-06-12 03:44 ------- Confirmed. -- What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever Confirmed| |1 Last reconfirmed|0000-00-00 00:00:00 |2005-06-12 03:44:19 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21829 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/21829] [4.1 Regression] missed jump threading after unroller 2005-05-30 19:06 [Bug tree-optimization/21829] New: [4.1 Regression] missed jump threading after unroller pinskia at gcc dot gnu dot org 2005-05-30 19:21 ` [Bug tree-optimization/21829] " pinskia at gcc dot gnu dot org 2005-06-12 3:44 ` pinskia at gcc dot gnu dot org @ 2005-09-10 5:56 ` pinskia at gcc dot gnu dot org 2 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu dot org @ 2005-09-10 5:56 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From pinskia at gcc dot gnu dot org 2005-09-10 05:56 ------- We now get: <bb 0>: if (v_8 < 0) goto <L1>; else goto <L14>; Invalid sum of incoming frequencies 2500, should be 1775 <L14>:; if (v_8 <= 0) goto <L1>; else goto <L3>; <L1>:; Invalid sum of incoming frequencies 4275, should be 5000 # x_1 = PHI <0(1), 1(2)>; <L3>:; return x_1; Which means jump threading is also messing up the frequencies :(. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21829 ^ permalink raw reply [flat|nested] 6+ messages in thread
[parent not found: <bug-21829-6528@http.gcc.gnu.org/bugzilla/>]
* [Bug tree-optimization/21829] [4.1 Regression] missed jump threading after unroller [not found] <bug-21829-6528@http.gcc.gnu.org/bugzilla/> @ 2005-10-29 15:52 ` pinskia at gcc dot gnu dot org 2005-10-30 23:32 ` pinskia at gcc dot gnu dot org 1 sibling, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu dot org @ 2005-10-29 15:52 UTC (permalink / raw) To: gcc-bugs ------- Comment #3 from pinskia at gcc dot gnu dot org 2005-10-29 15:52 ------- This really does not need to be targeted towards 4.1 (this is a bug I filed looking at code gen problems with some weird code which I made up). -- pinskia at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Last reconfirmed|2005-09-16 23:14:06 |2005-10-29 15:52:25 date| | Target Milestone|4.1.0 |4.2.0 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21829 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/21829] [4.1 Regression] missed jump threading after unroller [not found] <bug-21829-6528@http.gcc.gnu.org/bugzilla/> 2005-10-29 15:52 ` pinskia at gcc dot gnu dot org @ 2005-10-30 23:32 ` pinskia at gcc dot gnu dot org 1 sibling, 0 replies; 6+ messages in thread 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=21829 ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2005-10-30 23:32 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2005-05-30 19:06 [Bug tree-optimization/21829] New: [4.1 Regression] missed jump threading after unroller pinskia at gcc dot gnu dot org 2005-05-30 19:21 ` [Bug tree-optimization/21829] " pinskia at gcc dot gnu dot org 2005-06-12 3:44 ` pinskia at gcc dot gnu dot org 2005-09-10 5:56 ` pinskia at gcc dot gnu dot org [not found] <bug-21829-6528@http.gcc.gnu.org/bugzilla/> 2005-10-29 15:52 ` pinskia at gcc dot gnu dot org 2005-10-30 23:32 ` pinskia at gcc dot gnu dot org
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