[Bug tree-optimization/88315] SAD and DOT_PROD SLP reductions with initial value != 0 create wrong code

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88315

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue Dec  4 08:23:40 2018
New Revision: 266771

URL: https://gcc.gnu.org/viewcvs?rev=266771&root=gcc&view=rev
Log:
2018-12-04  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/88315
        * tree-vect-loop.c (get_initial_defs_for_reduction): Simplify
        and fix initialization vector for SAD and DOT_PROD SLP reductions.

        * gcc.dg/vect/slp-reduc-sad.c: Adjust to provide non-trivial
        initial value.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/vect/slp-reduc-sad.c
    trunk/gcc/tree-vect-loop.c