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 <mjam...@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
