[Bug tree-optimization/113135] [14 regression] ICE when building unrar (error: PHI node with wrong VUSE on edge from BB 46)

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113135

--- Comment #6 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Tamar Christina <tnfchris@gcc.gnu.org>:

https://gcc.gnu.org/g:6cb155a6cf314232248a12bdd395ed4151ae5a28

commit r14-7194-g6cb155a6cf314232248a12bdd395ed4151ae5a28
Author: Tamar Christina <tamar.christina@arm.com>
Date:   Fri Jan 12 15:24:49 2024 +0000

    middle-end: make memory analysis for early break more deterministic
[PR113135]

    Instead of searching for where to move stores to, they should always be in
    exit belonging to the latch.  We can only ever delay stores and even if we
    pick a different exit than the latch one as the main one, effects still
    happen in program order when vectorized.  If we don't move the stores to
the
    latch exit but instead to whever we pick as the "main" exit then we can
    perform incorrect memory accesses (luckily these are trapped by
verify_ssa).

    We used to iterate over the conds and check the loads and stores inside
them.
    However this relies on the conds being ordered in program order. 
Additionally
    if there is a basic block between two conds we would not have analyzed it.

    Instead this now walks from the preds of the destination basic block up to
the
    loop header and analyzes every block along the way.  As a later
optimization we
    could stop as soon as we've seen all the BBs we have conds for.  For now
the
    header will always contain the first cond, but this can change when we
support
    arbitrary control flow.

    gcc/ChangeLog:

            PR tree-optimization/113135
            * tree-vect-data-refs.cc (vect_analyze_early_break_dependences):
Rework
            dependency analysis.

    gcc/testsuite/ChangeLog:

            PR tree-optimization/113135
            * gcc.dg/vect/vect-early-break_103-pr113135.c: New test.