[Bug tree-optimization/70754] [6 Regression] ICE during predictive commoning

[amker at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70754

--- Comment #19 from amker at gcc dot gnu.org ---
Author: amker
Date: Wed Nov 15 16:20:21 2017
New Revision: 254778

URL: https://gcc.gnu.org/viewcvs?rev=254778&root=gcc&view=rev
Log:
        PR tree-optimization/82726
        PR tree-optimization/70754
        * tree-predcom.c (order_drefs_by_pos): New function.
        (combine_chains): Move code setting has_max_use_after to...
        (try_combine_chains): ...here.  New parameter.  Sort combined chains
        according to position information.
        (tree_predictive_commoning_loop): Update call to above function.
        (update_pos_for_combined_chains, pcom_stmt_dominates_stmt_p): New.

        gcc/testsuite
        * gcc.dg/tree-ssa/pr82726.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/pr82726.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/tree-predcom.c