[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 #31 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Wed Oct 30 09:21:09 2019
New Revision: 277603

URL: https://gcc.gnu.org/viewcvs?rev=277603&root=gcc&view=rev
Log:
2019-10-30  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/65930
        * tree-vect-loop.c (vect_is_simple_reduction): For reduction
        chains also allow a leading and trailing conversion.
        * tree-vect-slp.c (vect_get_and_check_slp_defs): Handle
        intermediate reduction chains.
        (vect_analyze_slp_instance): Likewise.  Build a SLP
        node for a trailing conversion manually.

        * gcc.dg/vect/pr65930-2.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/vect/pr65930-2.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vect-loop.c
    trunk/gcc/tree-vect-slp.c