[Bug fortran/67170] PRE can't hoist out a readonly argument

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67170

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue Sep 29 13:04:18 2015
New Revision: 228244

URL: https://gcc.gnu.org/viewcvs?rev=228244&root=gcc&view=rev
Log:
2015-09-29  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/67170
        * tree-ssa-alias.h (get_continuation_for_phi): Adjust
        the translate function pointer parameter to get the
        bool whether to disambiguate only by reference.
        (walk_non_aliased_vuses): Likewise.
        * tree-ssa-alias.c (maybe_skip_until): Adjust.
        (get_continuation_for_phi_1): Likewise.
        (get_continuation_for_phi): Likewise.
        (walk_non_aliased_vuses): Likewise.
        * tree-ssa-sccvn.c (const_parms): New bitmap.
        (vn_reference_lookup_3): Adjust for interface change.
        Disambiguate parameters pointing to readonly memory.
        (free_scc_vn): Free const_parms.
        (run_scc_vn): Initialize const_parms from a fn spec attribute.

        * gfortran.dg/pr67170.f90: New testcase.

Added:
    trunk/gcc/testsuite/gfortran.dg/pr67170.f90
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-alias.c
    trunk/gcc/tree-ssa-alias.h
    trunk/gcc/tree-ssa-sccvn.c