From 47c39faa67cc7bd567793b62718ab5e4f931e8d0 Mon Sep 17 00:00:00 2001 From: guojiufu Date: Mon, 27 Apr 2020 14:08:20 +0800 Subject: [PATCH] rs6000: enable -fweb for small loops unrolling Previously -fweb was disabled if only unroll small loops. After that we find there is cases where it could help to rename pseudos and avoid some anti-dependence which may occur after unroll. This patch enables -fweb for small loops unrolling. 2020-04-27 Jiufu Guo * common/config/rs6000/rs6000-common.c (rs6000_option_optimization_table) [OPT_LEVELS_ALL]: Remove turn off -fweb. * config/rs6000/rs6000.c (rs6000_option_override_internal): Avoid to set flag_web. --- gcc/ChangeLog | 8 ++++++++ gcc/common/config/rs6000/rs6000-common.c | 6 +++--- gcc/config/rs6000/rs6000.c | 4 +--- 3 files changed, 12 insertions(+), 6 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 54cc55c5e8d..477d2a7163c 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2020-04-27 Jiufu Guo + + * common/config/rs6000/rs6000-common.c + (rs6000_option_optimization_table) [OPT_LEVELS_ALL]: Remove turn off + -fweb. + * config/rs6000/rs6000.c (rs6000_option_override_internal): Avoid to + set flag_web. + 2020-04-27 Martin Liska PR lto/94659 diff --git a/gcc/common/config/rs6000/rs6000-common.c b/gcc/common/config/rs6000/rs6000-common.c index 4f38d566844..ee37b9dc90b 100644 --- a/gcc/common/config/rs6000/rs6000-common.c +++ b/gcc/common/config/rs6000/rs6000-common.c @@ -38,9 +38,9 @@ static const struct default_options rs6000_option_optimization_table[] = loops at -O2 and above by default. */ { OPT_LEVELS_2_PLUS_SPEED_ONLY, OPT_funroll_loops, NULL, 1 }, { OPT_LEVELS_2_PLUS_SPEED_ONLY, OPT_munroll_only_small_loops, NULL, 1 }, - /* -fweb and -frename-registers are useless in general for rs6000, - turn them off. */ - { OPT_LEVELS_ALL, OPT_fweb, NULL, 0 }, + + /* -frename-registers leads to non-optimal codegen and performance + on rs6000, turn it off by default. */ { OPT_LEVELS_ALL, OPT_frename_registers, NULL, 0 }, /* Double growth factor to counter reduced min jump length. */ diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c index aa632ea8f4a..2007617cdee 100644 --- a/gcc/config/rs6000/rs6000.c +++ b/gcc/config/rs6000/rs6000.c @@ -4557,7 +4557,7 @@ rs6000_option_override_internal (bool global_init_p) SCHED_PRESSURE_MODEL); /* Explicit -funroll-loops turns -munroll-only-small-loops off, and - turns -fweb and -frename-registers on. */ + turns -frename-registers on. */ if ((global_options_set.x_flag_unroll_loops && flag_unroll_loops) || (global_options_set.x_flag_unroll_all_loops && flag_unroll_all_loops)) @@ -4566,8 +4566,6 @@ rs6000_option_override_internal (bool global_init_p) unroll_only_small_loops = 0; if (!global_options_set.x_flag_rename_registers) flag_rename_registers = 1; - if (!global_options_set.x_flag_web) - flag_web = 1; } /* If using typedef char *va_list, signal that -- 2.30.2