From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by sourceware.org (Postfix) with ESMTPS id D2FC43858C52 for ; Sat, 19 Nov 2022 06:25:36 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org D2FC43858C52 Authentication-Results: sourceware.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=gmail.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1668839136; x=1700375136; h=from:to:cc:subject:date:message-id; bh=5hO643+n63oWkRUDeKOL3SSgCupuew9u8e37+hM1EJY=; b=bhfWWreM31Ko89HOetjOd+uQtaHY0uOTrs/77XK6t3Z5ibl1uBixgYfO F9fX+V9fUZJISGJEK4fS0gX8xw+n7D9nfU9XIfKrIe3puqdUveLE2Sqf+ 3K8FKXBzx4mvq3JOGmHBo7xKC27gL0uW6+yUzHU2ImrkIjuRXvhs4v7/8 VFcZI20lnV5fynPR3TCpMNHq0LoxkS0O+vaAsU7cyMQjuxaOR5Ed9cLJV nLFF28ipOozadmIFkfzb3peovQ9LObZ4PgzUT3v7txDPmy6UdUn68BYsB XZt/NMtqpLTXqUY/OgM3/voprzczoleKTBAwEOnKbm3TSu7n/04Fg8J7x w==; X-IronPort-AV: E=McAfee;i="6500,9779,10535"; a="310927896" X-IronPort-AV: E=Sophos;i="5.96,175,1665471600"; d="scan'208";a="310927896" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Nov 2022 22:25:35 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10535"; a="709277606" X-IronPort-AV: E=Sophos;i="5.96,175,1665471600"; d="scan'208";a="709277606" Received: from shvmail03.sh.intel.com ([10.239.245.20]) by fmsmga004.fm.intel.com with ESMTP; 18 Nov 2022 22:25:33 -0800 Received: from shliclel320.sh.intel.com (shliclel320.sh.intel.com [10.239.240.127]) by shvmail03.sh.intel.com (Postfix) with ESMTP id 85F2D10054F8; Sat, 19 Nov 2022 14:25:32 +0800 (CST) From: Hongyu Wang To: gcc-patches@gcc.gnu.org Cc: richard.guenther@gmail.com, ubizjak@gmail.com, hongtao.liu@intel.com Subject: [PATCH] i386: Only enable small loop unrolling in backend [PR 107602] Date: Sat, 19 Nov 2022 14:25:32 +0800 Message-Id: <20221119062532.75190-1-hongyu.wang@intel.com> X-Mailer: git-send-email 2.18.1 X-Spam-Status: No, score=-10.9 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_ENVFROM_END_DIGIT,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,GIT_PATCH_0,HEADER_FROM_DIFFERENT_DOMAINS,KAM_SHORT,SPF_HELO_NONE,SPF_SOFTFAIL,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Hi, Followed by the discussion in pr107602, -munroll-only-small-loops Does not turns on/off -funroll-loops, and current check in pass_rtl_unroll_loops::gate would cause -funroll-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. Bootstrapped and regtested on x86-64-pc-linux-gnu. Ok for trunk? gcc/ChangeLog: PR target/107602 * 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/107602 * gcc.target/i386/pr86270.c: Add -fno-unroll-loops. * gcc.target/i386/pr93002.c: Likewise. --- 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.target/i386/pr86270.c | 2 +- gcc/testsuite/gcc.target/i386/pr93002.c | 2 +- 6 files changed, 49 insertions(+), 26 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 292b32c5e99..10f8b4e91a5 100644 --- a/gcc/config/i386/i386.cc +++ b/gcc/config/i386/i386.cc @@ -23829,20 +23829,12 @@ 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.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; -- 2.18.1