[Bug middle-end/90796] [8/9/10 Regression] GCC: O2 vs O3 output differs on simple test

[matz at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90796

--- Comment #12 from Michael Matz <matz at gcc dot gnu.org> ---
Author: matz
Date: Tue Oct 22 12:25:03 2019
New Revision: 277287

URL: https://gcc.gnu.org/viewcvs?rev=277287&root=gcc&view=rev
Log:
Fix PR middle-end/90796

        PR middle-end/90796
        * gimple-loop-jam.c (any_access_function_variant_p): New function.
        (adjust_unroll_factor): Use it to constrain safety, new parameter.
        (tree_loop_unroll_and_jam): Adjust call and profitable unroll factor.

testsuite/
        * gcc.dg/unroll-and-jam.c: Add three invalid and one valid case.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/gimple-loop-jam.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/unroll-and-jam.c