[Bug tree-optimization/65930] Reduction with sign-change not handled

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65930

--- Comment #30 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue Oct 29 09:33:49 2019
New Revision: 277566

URL: https://gcc.gnu.org/viewcvs?rev=277566&root=gcc&view=rev
Log:
2019-10-29  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/65930
        * tree-vect-loop.c (check_reduction_path): Relax single-use
        check allowing out-of-loop uses.
        (vect_is_simple_reduction): SLP reduction chains cannot have
        intermediate stmts used outside of the loop.
        (vect_create_epilog_for_reduction): The adjustment might need
        to be converted.
        (vectorizable_reduction): Annotate live stmts of the reduction
        chain with STMT_VINFO_REDUC_DEF.
        * tree-vect-stms.c (process_use): Remove no longer true asserts.

        * gcc.dg/vect/pr65930-1.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/vect/pr65930-1.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vect-loop.c
    trunk/gcc/tree-vect-stmts.c