[Bug tree-optimization/104263] [10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O2 -fnon-call-exceptions -fno-inline-small-functions since r10-3575-g629387a6586a7531
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104263 --- Comment #10 from CVS Commits --- The master branch has been updated by Jakub Jelinek : https://gcc.gnu.org/g:a591c71b41e18e4ff86852a974592af4962aef57 commit r12-6923-ga591c71b41e18e4ff86852a974592af4962aef57 Author: Jakub Jelinek Date: Fri Jan 28 19:02:26 2022 +0100 store-merging: Fix up a -fcompare-debug bug in get_status_for_store_merging [PR104263] As mentioned in the PRthe following testcase fails, because the last stmt of a bb with -g is a debug stmt and get_status_for_store_merging uses gimple_seq_last_stmt (bb_seq (bb)) when testing if it is valid for store merging. The debug stmt isn't valid, while a stmt at that position with -g0 is valid and so the divergence. As we walk the whole bb already, this patch just remembers the last non-debug stmt, so that we don't need to skip backwards debug stmts at the end of the bb to find last real stmt. 2022-01-28 Jakub Jelinek PR tree-optimization/104263 * gimple-ssa-store-merging.cc (get_status_for_store_merging): For cfun->can_throw_non_call_exceptions && cfun->eh test whether last non-debug stmt in the bb is store_valid_for_store_merging_p rather than last stmt. * gcc.dg/pr104263.c: New test.
[Bug tree-optimization/104263] [10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O2 -fnon-call-exceptions -fno-inline-small-functions since r10-3575-g629387a6586a7531
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104263 --- Comment #9 from CVS Commits --- The master branch has been updated by Richard Biener : https://gcc.gnu.org/g:5b6f04276e3d1f20817ed37b2e26e43bd12cc0d2 commit r12-6917-g5b6f04276e3d1f20817ed37b2e26e43bd12cc0d2 Author: Richard Biener Date: Fri Jan 28 10:55:29 2022 +0100 tree-optimization/104263 - avoid retaining abnormal edges for non-call/goto stmts This removes a premature optimization from gimple_purge_dead_abnormal_call_edges which, after eliding the last setjmp (or computed goto) statement from a function and thus clearing cfun->calls_setjmp, leaves us with the abnormal edges from other calls that are elided for example via inlining or DCE. That's a CFG / IL combination that should be impossible (not addressing the fact that with cfun->calls_setjmp and cfun->has_nonlocal_label cleared we should not have any abnormal edge at all). For the testcase in the PR this means that IPA inlining will remove the abormal edges from the block after inlining the call the edge was coming from. 2022-01-28 Richard Biener PR tree-optimization/104263 * tree-cfg.cc (gimple_purge_dead_abnormal_call_edges): Purge edges also when !cfun->has_nonlocal_label and !cfun->calls_setjmp. * gcc.dg/tree-ssa/inline-13.c: New testcase.
[Bug tree-optimization/104263] [10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O2 -fnon-call-exceptions -fno-inline-small-functions since r10-3575-g629387a6586a7531
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104263 --- Comment #8 from Eric Botcazou --- > Untested fix for the store-merging bug. FWIW it looks good to me, thanks!
[Bug tree-optimization/104263] [10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O2 -fnon-call-exceptions -fno-inline-small-functions since r10-3575-g629387a6586a7531
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104263 Jakub Jelinek changed: What|Removed |Added Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |jakub at gcc dot gnu.org --- Comment #7 from Jakub Jelinek --- Created attachment 52309 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52309=edit gcc12-pr104263.patch Untested fix for the store-merging bug.
[Bug tree-optimization/104263] [10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O2 -fnon-call-exceptions -fno-inline-small-functions since r10-3575-g629387a6586a7531
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104263 --- Comment #6 from Richard Biener --- I'm testing a patch to gimple_purge_dead_abnormal_call_edges, leaving the store-merging issue to Jakub.
[Bug tree-optimization/104263] [10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O2 -fnon-call-exceptions -fno-inline-small-functions since r10-3575-g629387a6586a7531
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104263 --- Comment #5 from Richard Biener --- OK, so with the abnormal edges the issue is that DCE1 removes the recursive call to foo () (because the function is "wrongly" pure) which causes us to clear cfun->calls_setjmp but then any further gimple_purge_dead_abnormal_call_edges will simply do nothing (as premature optimization one could guess). So the bug would be that we fail to wipe all abnormal edges when a function no longer calls setjmp or has a nonlocal label. The easiest fix is to remove the premature optimization in gimple_purge_dead_abnormal_call_edges. That leaves the abnormal edges from bar() even after DCE removes the recursive call to foo() (still a missed optimization) but it at least will not leave us with stray abnormal edges from non-call / non-computed goto stmts in the IL. It also resolves the compare-debug failure for this testcase (but maybe there's a latent issue in store-merging still).
[Bug tree-optimization/104263] [10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O2 -fnon-call-exceptions -fno-inline-small-functions since r10-3575-g629387a6586a7531
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104263 Martin Liška changed: What|Removed |Added Summary|[10/11/12 Regression] |[10/11/12 Regression] |'-fcompare-debug' failure |'-fcompare-debug' failure |(length) w/ -O2 |(length) w/ -O2 |-fnon-call-exceptions |-fnon-call-exceptions |-fno-inline-small-functions |-fno-inline-small-functions ||since ||r10-3575-g629387a6586a7531 CC||ebotcazou at gcc dot gnu.org, ||marxin at gcc dot gnu.org --- Comment #4 from Martin Liška --- Started with r10-3575-g629387a6586a7531.
