[Bug tree-optimization/86991] [8/9 Regression] ICE in vectorizable_reduction, at tree-vect-loop.c:6919
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86991 --- Comment #5 from Richard Biener --- Author: rguenth Date: Tue Nov 13 16:14:37 2018 New Revision: 266081 URL: https://gcc.gnu.org/viewcvs?rev=266081=gcc=rev Log: 2018-11-13 Richard Biener PR tree-optimization/86991 * tree-vect-loop.c (vect_is_slp_reduction): Delay reduction group building until we have successfully detected the SLP reduction. (vect_is_simple_reduction): Remove fixup code here. * gcc.dg/pr86991.c: New testcase. Added: trunk/gcc/testsuite/gcc.dg/pr86991.c Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-vect-loop.c
[Bug tree-optimization/86991] [8/9 Regression] ICE in vectorizable_reduction, at tree-vect-loop.c:6919
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86991 --- Comment #4 from Richard Biener --- So the reason in the end is failure to tear down a half-built reduction chain. I have a fix (finally).
[Bug tree-optimization/86991] [8/9 Regression] ICE in vectorizable_reduction, at tree-vect-loop.c:6919
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86991 --- Comment #3 from Richard Biener --- Hmm. To me it looks like the assert that triggers: if (orig_stmt_info) gcc_assert (tmp == orig_stmt_info || REDUC_GROUP_FIRST_ELEMENT (tmp) == orig_stmt_info); else /* We changed STMT to be the first stmt in reduction chain, hence we check that in this case the first element in the chain is STMT. */ gcc_assert (tmp == stmt_info || REDUC_GROUP_FIRST_ELEMENT (tmp) == stmt_info); doesn't work this way for SLP reductions with a reduction path since tmp (STMT_VINFO_REDUC_DEF) is obviously different from stmt_info (the first non-PHI). But what the vectorizer tries to do makes sense. Maybe test coverage was too low to uncover this up until now. It looks like the testcase relies on some unfortunate invariant code in the IL. Did you have a testcase that computed sth more meaningful?
[Bug tree-optimization/86991] [8/9 Regression] ICE in vectorizable_reduction, at tree-vect-loop.c:6919
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86991 Richard Biener changed: What|Removed |Added Priority|P3 |P2 Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org --- Comment #2 from Richard Biener --- I will have a look.
[Bug tree-optimization/86991] [8/9 Regression] ICE in vectorizable_reduction, at tree-vect-loop.c:6919
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86991 Martin Liška changed: What|Removed |Added Keywords||ice-on-valid-code Status|UNCONFIRMED |NEW Last reconfirmed||2018-08-21 CC||marxin at gcc dot gnu.org, ||rguenth at gcc dot gnu.org Target Milestone|--- |8.3 Summary|internal compiler error: in |[8/9 Regression] ICE in |vectorizable_reduction, at |vectorizable_reduction, at |tree-vect-loop.c:6919 |tree-vect-loop.c:6919 Ever confirmed|0 |1 --- Comment #1 from Martin Liška --- Confirmed, started with r250382.
