From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 7879) id 59367385843E; Wed, 15 Feb 2023 10:22:33 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 59367385843E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1676456553; bh=rOauAeRwRoreGxFGxJmsxYwimk3mAPsyENwxDheFueI=; h=From:To:Subject:Date:From; b=PUJuLplXcsj5IrXSTjfT1mBVbukExc28j/cPkVkybBOXcJ+wAt50BkX6YkanqntPX UyKrkX2+Ax7ud0XsY6kaQRLQfd5aKrGeJRo0Xs9drdQisXwE1+cTe/qKGDgqm9/mNU dVC2CMd9yFGT+w8oyXzu5WPaEVQ+LnGSlk1HBqMw= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Filip Kastl To: gcc-cvs@gcc.gnu.org Subject: [gcc(refs/users/pheeck/heads/sccp)] i386: Only enable small loop unrolling in backend [PR 107692] X-Act-Checkin: gcc X-Git-Author: Hongyu Wang X-Git-Refname: refs/users/pheeck/heads/sccp X-Git-Oldrev: 1c9e62f5002094940d596ee7b841656772dca5bc X-Git-Newrev: aba7278d1001a95fe9677bfa14155f7437a4aac0 Message-Id: <20230215102233.59367385843E@sourceware.org> Date: Wed, 15 Feb 2023 10:22:33 +0000 (GMT) List-Id: https://gcc.gnu.org/g:aba7278d1001a95fe9677bfa14155f7437a4aac0 commit aba7278d1001a95fe9677bfa14155f7437a4aac0 Author: Hongyu Wang Date: Sat Nov 19 09:38:00 2022 +0800 i386: Only enable small loop unrolling in backend [PR 107692] Followed by the discussion in pr107692, -munroll-only-small-loops Does not turns on/off -funroll-loops, and current check in pass_rtl_unroll_loops::gate would cause -fno-unroll-loops do not take effect. Revert the change about targetm.loop_unroll_adjust and apply the backend option change to strictly follow the rule that -funroll-loops takes full control of loop unrolling, and munroll-only-small-loops just change its behavior to unroll small size loops. gcc/ChangeLog: PR target/107692 * common/config/i386/i386-common.cc (ix86_optimization_table): Enable loop unroll O2, disable -fweb and -frename-registers by default. * config/i386/i386-options.cc (ix86_override_options_after_change): Disable small loop unroll when funroll-loops enabled, reset cunroll_grow_size when it is not explicitly enabled. (ix86_option_override_internal): Call ix86_override_options_after_change instead of calling ix86_recompute_optlev_based_flags and ix86_default_align separately. * config/i386/i386.cc (ix86_loop_unroll_adjust): Adjust unroll factor if -munroll-only-small-loops enabled. * loop-init.cc (pass_rtl_unroll_loops::gate): Do not enable loop unrolling for -O2-speed. (pass_rtl_unroll_loops::execute): Rmove targetm.loop_unroll_adjust check. gcc/testsuite/ChangeLog: PR target/107692 * gcc.dg/guality/loop-1.c: Remove additional option for ia32. * gcc.target/i386/pr86270.c: Add -fno-unroll-loops. * gcc.target/i386/pr93002.c: Likewise. Diff: --- gcc/common/config/i386/i386-common.cc | 8 ++++++++ gcc/config/i386/i386-options.cc | 34 +++++++++++++++++++++++++++++---- gcc/config/i386/i386.cc | 18 +++++------------ gcc/loop-init.cc | 11 ++++------- gcc/testsuite/gcc.dg/guality/loop-1.c | 2 -- gcc/testsuite/gcc.target/i386/pr86270.c | 2 +- gcc/testsuite/gcc.target/i386/pr93002.c | 2 +- 7 files changed, 49 insertions(+), 28 deletions(-) diff --git a/gcc/common/config/i386/i386-common.cc b/gcc/common/config/i386/i386-common.cc index 6ce2a588adc..660a977b68b 100644 --- a/gcc/common/config/i386/i386-common.cc +++ b/gcc/common/config/i386/i386-common.cc @@ -1808,7 +1808,15 @@ static const struct default_options ix86_option_optimization_table[] = /* The STC algorithm produces the smallest code at -Os, for x86. */ { OPT_LEVELS_2_PLUS, OPT_freorder_blocks_algorithm_, NULL, REORDER_BLOCKS_ALGORITHM_STC }, + + /* Turn on -funroll-loops with -munroll-only-small-loops to enable small + loop unrolling at -O2. */ + { OPT_LEVELS_2_PLUS_SPEED_ONLY, OPT_funroll_loops, NULL, 1 }, { OPT_LEVELS_2_PLUS_SPEED_ONLY, OPT_munroll_only_small_loops, NULL, 1 }, + /* Turns off -frename-registers and -fweb which are enabled by + funroll-loops. */ + { OPT_LEVELS_ALL, OPT_frename_registers, NULL, 0 }, + { OPT_LEVELS_ALL, OPT_fweb, NULL, 0 }, /* Turn off -fschedule-insns by default. It tends to make the problem with not enough registers even worse. */ { OPT_LEVELS_ALL, OPT_fschedule_insns, NULL, 0 }, diff --git a/gcc/config/i386/i386-options.cc b/gcc/config/i386/i386-options.cc index e5c77f3a84d..bc1d36e36a8 100644 --- a/gcc/config/i386/i386-options.cc +++ b/gcc/config/i386/i386-options.cc @@ -1838,8 +1838,37 @@ ix86_recompute_optlev_based_flags (struct gcc_options *opts, void ix86_override_options_after_change (void) { + /* Default align_* from the processor table. */ ix86_default_align (&global_options); + ix86_recompute_optlev_based_flags (&global_options, &global_options_set); + + /* Disable unrolling small loops when there's explicit + -f{,no}unroll-loop. */ + if ((OPTION_SET_P (flag_unroll_loops)) + || (OPTION_SET_P (flag_unroll_all_loops) + && flag_unroll_all_loops)) + { + if (!OPTION_SET_P (ix86_unroll_only_small_loops)) + ix86_unroll_only_small_loops = 0; + /* Re-enable -frename-registers and -fweb if funroll-loops + enabled. */ + if (!OPTION_SET_P (flag_web)) + flag_web = flag_unroll_loops; + if (!OPTION_SET_P (flag_rename_registers)) + flag_rename_registers = flag_unroll_loops; + /* -fcunroll-grow-size default follws -f[no]-unroll-loops. */ + if (!OPTION_SET_P (flag_cunroll_grow_size)) + flag_cunroll_grow_size = flag_unroll_loops + || flag_peel_loops + || optimize >= 3; + } + else + { + if (!OPTION_SET_P (flag_cunroll_grow_size)) + flag_cunroll_grow_size = flag_peel_loops || optimize >= 3; + } + } /* Clear stack slot assignments remembered from previous functions. @@ -2351,7 +2380,7 @@ ix86_option_override_internal (bool main_args_p, set_ix86_tune_features (opts, ix86_tune, opts->x_ix86_dump_tunes); - ix86_recompute_optlev_based_flags (opts, opts_set); + ix86_override_options_after_change (); ix86_tune_cost = processor_cost_table[ix86_tune]; /* TODO: ix86_cost should be chosen at instruction or function granuality @@ -2382,9 +2411,6 @@ ix86_option_override_internal (bool main_args_p, || TARGET_64BIT_P (opts->x_ix86_isa_flags)) opts->x_ix86_regparm = REGPARM_MAX; - /* Default align_* from the processor table. */ - ix86_default_align (opts); - /* Provide default for -mbranch-cost= value. */ SET_OPTION_IF_UNSET (opts, opts_set, ix86_branch_cost, ix86_tune_cost->branch_cost); diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc index 14719d397a4..881cd9f3bb7 100644 --- a/gcc/config/i386/i386.cc +++ b/gcc/config/i386/i386.cc @@ -23828,20 +23828,12 @@ ix86_loop_unroll_adjust (unsigned nunroll, class loop *loop) /* Unroll small size loop when unroll factor is not explicitly specified. */ - if (!(flag_unroll_loops - || flag_unroll_all_loops - || loop->unroll)) + if (ix86_unroll_only_small_loops && !loop->unroll) { - nunroll = 1; - - /* Any explicit -f{no-}unroll-{all-}loops turns off - -munroll-only-small-loops. */ - if (ix86_unroll_only_small_loops - && !OPTION_SET_P (flag_unroll_loops) - && loop->ninsns <= ix86_cost->small_unroll_ninsns) - nunroll = ix86_cost->small_unroll_factor; - - return nunroll; + if (loop->ninsns <= ix86_cost->small_unroll_ninsns) + return MIN (nunroll, ix86_cost->small_unroll_factor); + else + return 1; } if (!TARGET_ADJUST_UNROLL) diff --git a/gcc/loop-init.cc b/gcc/loop-init.cc index 9789efa1e11..f03c077cae1 100644 --- a/gcc/loop-init.cc +++ b/gcc/loop-init.cc @@ -565,12 +565,10 @@ public: {} /* opt_pass methods: */ - bool gate (function *fun) final override + bool gate (function *) final override { - return (flag_unroll_loops || flag_unroll_all_loops || cfun->has_unroll - || (targetm.loop_unroll_adjust - && optimize >= 2 - && optimize_function_for_speed_p (fun))); + return (flag_unroll_loops || flag_unroll_all_loops + || cfun->has_unroll); } unsigned int execute (function *) final override; @@ -586,8 +584,7 @@ pass_rtl_unroll_loops::execute (function *fun) if (dump_file) df_dump (dump_file); - if (flag_unroll_loops - || targetm.loop_unroll_adjust) + if (flag_unroll_loops) flags |= UAP_UNROLL; if (flag_unroll_all_loops) flags |= UAP_UNROLL_ALL; diff --git a/gcc/testsuite/gcc.dg/guality/loop-1.c b/gcc/testsuite/gcc.dg/guality/loop-1.c index a32ea445a3f..1b1f6d32271 100644 --- a/gcc/testsuite/gcc.dg/guality/loop-1.c +++ b/gcc/testsuite/gcc.dg/guality/loop-1.c @@ -1,7 +1,5 @@ /* { dg-do run } */ /* { dg-options "-fno-tree-scev-cprop -fno-tree-vectorize -g" } */ -/* { dg-additional-options "-mno-unroll-only-small-loops" { target ia32 } } */ - #include "../nop.h" diff --git a/gcc/testsuite/gcc.target/i386/pr86270.c b/gcc/testsuite/gcc.target/i386/pr86270.c index cbc9fbb0450..98b012caf23 100644 --- a/gcc/testsuite/gcc.target/i386/pr86270.c +++ b/gcc/testsuite/gcc.target/i386/pr86270.c @@ -1,5 +1,5 @@ /* { dg-do compile } */ -/* { dg-options "-O2 -mno-unroll-only-small-loops" } */ +/* { dg-options "-O2 -fno-unroll-loops" } */ int *a; long len; diff --git a/gcc/testsuite/gcc.target/i386/pr93002.c b/gcc/testsuite/gcc.target/i386/pr93002.c index f75a847f75d..7e2d869e17b 100644 --- a/gcc/testsuite/gcc.target/i386/pr93002.c +++ b/gcc/testsuite/gcc.target/i386/pr93002.c @@ -1,6 +1,6 @@ /* PR target/93002 */ /* { dg-do compile } */ -/* { dg-options "-O2 -mno-unroll-only-small-loops" } */ +/* { dg-options "-O2 -fno-unroll-loops" } */ /* { dg-final { scan-assembler-not "cmp\[^\n\r]*-1" } } */ volatile int sink;