[Bug target/82862] [8 Regression] SPEC CPU2006 465.tonto performance regression with r253975 (up to 40% drop for particular loop)

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82862

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Fri Feb 16 13:47:25 2018
New Revision: 257734

URL: https://gcc.gnu.org/viewcvs?rev=257734&root=gcc&view=rev
Log:
2018-02-16  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/84037
        PR tree-optimization/84016
        PR target/82862
        * config/i386/i386.c (ix86_builtin_vectorization_cost):
        Adjust vec_construct for the fact we need additional higher latency
        128bit inserts for AVX256 and AVX512 vector builds.
        (ix86_add_stmt_cost): Scale vector construction cost for
        elementwise loads.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/i386.c