[Bug tree-optimization/104263] [10/11 Regression] '-fcompare-debug' failure (length) w/ -O2 -fnon-call-exceptions -fno-inline-small-functions since r10-3575-g629387a6586a7531

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104263

--- Comment #12 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Jakub Jelinek
<jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:73b30d18a04bd6efa7e25c28dac1c863dc1cb06e

commit r11-9595-g73b30d18a04bd6efa7e25c28dac1c863dc1cb06e
Author: Jakub Jelinek <jakub@redhat.com>
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  <jakub@redhat.com>

            PR tree-optimization/104263
            * gimple-ssa-store-merging.c (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.

    (cherry picked from commit a591c71b41e18e4ff86852a974592af4962aef57)