[Bug tree-optimization/87008] [8 Regression] gimple mem-to-mem assignment badly optimized

[jamborm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87008

--- Comment #12 from Martin Jambor <jamborm at gcc dot gnu.org> ---
Author: jamborm
Date: Wed Apr 17 15:52:16 2019
New Revision: 270414

URL: https://gcc.gnu.org/viewcvs?rev=270414&root=gcc&view=rev
Log:
2019-04-17  Martin Jambor  <mjam...@suse.cz>

        Backport from mainline
        2019-03-10  Martin Jambor  <mjam...@suse.cz>

        PR tree-optimization/85762
        PR tree-optimization/87008
        PR tree-optimization/85459
        * tree-sra.c (contains_vce_or_bfcref_p): New parameter, set the bool
        it points to if there is a type changing MEM_REF.  Adjust all callers.
        (build_accesses_from_assign): Disable total scalarization if
        contains_vce_or_bfcref_p returns true through the new parameter, for
        both rhs and lhs.

        testsuite/
        * g++.dg/tree-ssa/pr87008.C: New test.
        * gcc.dg/guality/pr54970.c: Xfail tests querying a[0] everywhere.


Added:
    branches/gcc-8-branch/gcc/testsuite/g++.dg/tree-ssa/pr87008.C
Modified:
    branches/gcc-8-branch/gcc/ChangeLog
    branches/gcc-8-branch/gcc/testsuite/ChangeLog
    branches/gcc-8-branch/gcc/testsuite/gcc.dg/guality/pr54970.c
    branches/gcc-8-branch/gcc/tree-sra.c