[Bug target/81616] Update -mtune=generic for the current Intel and AMD processors

[jamborm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81616

--- Comment #44 from Martin Jambor <jamborm at gcc dot gnu.org> ---
Author: jamborm
Date: Fri Jan 12 14:06:10 2018
New Revision: 256581

URL: https://gcc.gnu.org/viewcvs?rev=256581&root=gcc&view=rev
Log:
Deferring FMA transformations in tight loops

2018-01-12  Martin Jambor  <mjambor@suse.cz>

        PR target/81616
        * params.def: New parameter PARAM_AVOID_FMA_MAX_BITS.
        * tree-ssa-math-opts.c: Include domwalk.h.
        (convert_mult_to_fma_1): New function.
        (fma_transformation_info): New type.
        (fma_deferring_state): Likewise.
        (cancel_fma_deferring): New function.
        (result_of_phi): Likewise.
        (last_fma_candidate_feeds_initial_phi): Likewise.
        (convert_mult_to_fma): Added deferring logic, split actual
        transformation to convert_mult_to_fma_1.
        (math_opts_dom_walker): New type.
        (math_opts_dom_walker::after_dom_children): New method, body moved
        here from pass_optimize_widening_mul::execute, added deferring logic
        bits.
        (pass_optimize_widening_mul::execute): Moved most of code to
        math_opts_dom_walker::after_dom_children.
        * config/i386/x86-tune.def (X86_TUNE_AVOID_128FMA_CHAINS): New.
        * config/i386/i386.c (ix86_option_override_internal): Added
        maybe_setting of PARAM_AVOID_FMA_MAX_BITS.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/i386.c
    trunk/gcc/config/i386/x86-tune.def
    trunk/gcc/params.def
    trunk/gcc/tree-ssa-math-opts.c