[Bug tree-optimization/91975] worse code for small array copy using pointer arithmetic than array indexing

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91975

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Fri Nov 15 09:09:16 2019
New Revision: 278281

URL: https://gcc.gnu.org/viewcvs?rev=278281&root=gcc&view=rev
Log:
2019-11-15  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/92039
        PR tree-optimization/91975
        * tree-ssa-loop-ivcanon.c (constant_after_peeling): Revert
        previous change, treat invariants consistently as non-constant.
        (tree_estimate_loop_size): Ternary ops with just the first op
        constant are not optimized away.

        * gcc.dg/tree-ssa/cunroll-2.c: Revert to state previous to
        unroller adjustment.
        * g++.dg/tree-ssa/ivopts-3.C: Likewise.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/g++.dg/tree-ssa/ivopts-3.C
    trunk/gcc/testsuite/gcc.dg/tree-ssa/cunroll-2.c
    trunk/gcc/tree-ssa-loop-ivcanon.c