[Bug tree-optimization/104156] [12 Regression] -fcompare-debug failure with -O2 -funswitch-loops since r12-4526-gd8edfadfc7a9795b

[cvs-commit at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104156

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rgue...@gcc.gnu.org>:

https://gcc.gnu.org/g:f953c8bc5bf314a57a6ba347ee6f5f5e3f1dad53

commit r12-6790-gf953c8bc5bf314a57a6ba347ee6f5f5e3f1dad53
Author: Richard Biener <rguent...@suse.de>
Date:   Fri Jan 21 10:19:58 2022 +0100

    tree-optimization/104156 - fix unswitching compare-debug issue

    When hoisting guards the unswitching pass does not properly ignore
    debug stmts when looking for uses outside of the loop of defs
    produced in the skipped region.  The following rectifies this
    by instead collecting them and resetting them after the transform.

    2022-01-21  Richard Biener  <rguent...@suse.de>

            PR tree-optimization/104156
            * tree-ssa-loop-unswitch.cc (tree_unswitch_outer_loop):
            Collect and reset debug stmts with out-of-loop uses when
            hoisting guards.
            (find_loop_guard): Adjust.
            (empty_bb_without_guard_p): Likewise.  Ignore debug stmts.
            (used_outside_loop_p): Push debug uses to a vector of
            debug stmts to reset.
            (hoist_guard): Adjust -fopt-info category.

            * gcc.dg/loop-unswitch-6.c: New testcase.