From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1851) id D12C33858D1E; Wed, 30 Nov 2022 13:04:09 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org D12C33858D1E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1669813449; bh=gxtAVn7Lz1c+KgmuiC34mal2+G9qInWJ6gcbJhWIHnk=; h=From:To:Subject:Date:From; b=Q0dBY32XiMIwo1pikO/jwCr4GuGV+pPB3gUa5jlUIl7jXq1RUCrDJxEuMAb+pSk9X qVY/GyXAFmYUoBjORf22QWzhaDA0lq6Ip1sncnKmzNG/hsaPoQxchVTmvD8h3jB5pt 4ULHO0NNsvRK56paH5z9WBGQF3tJfWWsOdyHa+DE= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Martin Liska To: gcc-cvs@gcc.gnu.org Subject: [gcc r13-4409] Improve profile handling in switch lowering. X-Act-Checkin: gcc X-Git-Author: Martin Liska X-Git-Refname: refs/heads/master X-Git-Oldrev: b628cad9e093f7a33042fb9dd647f183394eefae X-Git-Newrev: 4fa25a7eb322f0a003c1eb15680c71ece345e01e Message-Id: <20221130130409.D12C33858D1E@sourceware.org> Date: Wed, 30 Nov 2022 13:04:09 +0000 (GMT) List-Id: https://gcc.gnu.org/g:4fa25a7eb322f0a003c1eb15680c71ece345e01e commit r13-4409-g4fa25a7eb322f0a003c1eb15680c71ece345e01e Author: Martin Liska Date: Mon Jan 24 15:45:38 2022 +0100 Improve profile handling in switch lowering. PR tree-optimization/101301 PR tree-optimization/103680 gcc/ChangeLog: * tree-switch-conversion.cc (bit_test_cluster::emit): Handle correctly remaining probability. (switch_decision_tree::try_switch_expansion): Fix BB's count where a cluster expansion happens. (switch_decision_tree::emit_cmp_and_jump_insns): Fill up also BB count. (switch_decision_tree::do_jump_if_equal): Likewise. (switch_decision_tree::emit_case_nodes): Handle special case for BT expansion which can also fallback to a default BB. * tree-switch-conversion.h (cluster::cluster): Add m_default_prob probability. Diff: --- gcc/tree-switch-conversion.cc | 57 +++++++++++++++++++++++++++++-------------- gcc/tree-switch-conversion.h | 8 +++++- 2 files changed, 46 insertions(+), 19 deletions(-) diff --git a/gcc/tree-switch-conversion.cc b/gcc/tree-switch-conversion.cc index 5291fb806b5..83ba1c1ca03 100644 --- a/gcc/tree-switch-conversion.cc +++ b/gcc/tree-switch-conversion.cc @@ -1538,10 +1538,12 @@ bit_test_cluster::emit (tree index_expr, tree index_type, test[k].target_bb = n->m_case_bb; test[k].label = n->m_case_label_expr; test[k].bits = 0; + test[k].prob = profile_probability::never (); count++; } test[k].bits += n->get_range (n->get_low (), n->get_high ()); + test[k].prob += n->m_prob; lo = tree_to_uhwi (int_const_binop (MINUS_EXPR, n->get_low (), minval)); if (n->get_high () == NULL_TREE) @@ -1629,6 +1631,11 @@ bit_test_cluster::emit (tree index_expr, tree index_type, /*simple=*/true, NULL_TREE, /*before=*/true, GSI_SAME_STMT); + profile_probability subtree_prob = m_subtree_prob; + profile_probability default_prob = m_default_prob; + if (!default_prob.initialized_p ()) + default_prob = m_subtree_prob.invert (); + if (m_handles_entire_switch && entry_test_needed) { tree range = int_const_binop (MINUS_EXPR, maxval, minval); @@ -1638,10 +1645,11 @@ bit_test_cluster::emit (tree index_expr, tree index_type, fold_convert (unsigned_index_type, range), /*simple=*/true, NULL_TREE, /*before=*/true, GSI_SAME_STMT); - tmp = fold_build2_loc (loc, GT_EXPR, boolean_type_node, idx, range); + tmp = fold_build2 (GT_EXPR, boolean_type_node, idx, range); + default_prob = default_prob / 2; basic_block new_bb = hoist_edge_and_branch_if_true (&gsi, tmp, default_bb, - profile_probability::unlikely (), loc); + default_prob, loc); gsi = gsi_last_bb (new_bb); } @@ -1662,14 +1670,12 @@ bit_test_cluster::emit (tree index_expr, tree index_type, else csui = tmp; - profile_probability prob = profile_probability::always (); - /* for each unique set of cases: if (const & csui) goto target */ for (k = 0; k < count; k++) { - prob = profile_probability::always ().apply_scale (test[k].bits, - bt_range); + profile_probability prob = test[k].prob / (subtree_prob + default_prob); + subtree_prob -= test[k].prob; bt_range -= test[k].bits; tmp = wide_int_to_tree (word_type_node, test[k].mask); tmp = fold_build2_loc (loc, BIT_AND_EXPR, word_type_node, csui, tmp); @@ -1912,9 +1918,13 @@ switch_decision_tree::try_switch_expansion (vec &clusters) /* Emit cluster-specific switch handling. */ for (unsigned i = 0; i < clusters.length (); i++) if (clusters[i]->get_type () != SIMPLE_CASE) - clusters[i]->emit (index_expr, index_type, - gimple_switch_default_label (m_switch), - m_default_bb, gimple_location (m_switch)); + { + edge e = single_pred_edge (clusters[i]->m_case_bb); + e->dest->count = e->src->count.apply_probability (e->probability); + clusters[i]->emit (index_expr, index_type, + gimple_switch_default_label (m_switch), + m_default_bb, gimple_location (m_switch)); + } } fix_phi_operands_for_edges (); @@ -2162,6 +2172,7 @@ switch_decision_tree::emit_cmp_and_jump_insns (basic_block bb, tree op0, edge false_edge = split_block (bb, cond); false_edge->flags = EDGE_FALSE_VALUE; false_edge->probability = prob.invert (); + false_edge->dest->count = bb->count.apply_probability (prob.invert ()); edge true_edge = make_edge (bb, label_bb, EDGE_TRUE_VALUE); true_edge->probability = prob; @@ -2192,6 +2203,7 @@ switch_decision_tree::do_jump_if_equal (basic_block bb, tree op0, tree op1, edge false_edge = split_block (bb, cond); false_edge->flags = EDGE_FALSE_VALUE; false_edge->probability = prob.invert (); + false_edge->dest->count = bb->count.apply_probability (prob.invert ()); edge true_edge = make_edge (bb, label_bb, EDGE_TRUE_VALUE); true_edge->probability = prob; @@ -2227,7 +2239,7 @@ switch_decision_tree::emit_case_nodes (basic_block bb, tree index, node->m_c->m_case_bb, p, loc); /* Since this case is taken at this point, reduce its weight from subtree_weight. */ - node->m_c->m_subtree_prob -= p; + node->m_c->m_subtree_prob -= node->m_c->m_prob; if (node->m_left != NULL && node->m_right != NULL) { @@ -2246,6 +2258,7 @@ switch_decision_tree::emit_case_nodes (basic_block bb, tree index, / (node->m_c->m_subtree_prob + default_prob)); bb = do_jump_if_equal (bb, index, node->m_right->m_c->get_low (), node->m_right->m_c->m_case_bb, p, loc); + node->m_c->m_subtree_prob -= node->m_right->m_c->m_prob; p = (node->m_left->m_c->m_prob / (node->m_c->m_subtree_prob + default_prob)); @@ -2261,6 +2274,7 @@ switch_decision_tree::emit_case_nodes (basic_block bb, tree index, p = ((node->m_right->m_c->m_subtree_prob + default_prob / 2) / (node->m_c->m_subtree_prob + default_prob)); + test_bb->count = bb->count.apply_probability (p); bb = emit_cmp_and_jump_insns (bb, index, node->m_c->get_high (), GT_EXPR, test_bb, p, loc); default_prob /= 2; @@ -2347,21 +2361,28 @@ switch_decision_tree::emit_case_nodes (basic_block bb, tree index, is the one to branch to. */ if (node->has_child () || node->m_c->get_type () != SIMPLE_CASE) { + bool is_bt = node->m_c->get_type () == BIT_TEST; + int parts = is_bt ? 3 : 2; + /* Branch to a label where we will handle it later. */ basic_block test_bb = split_edge (single_succ_edge (bb)); redirect_edge_succ (single_pred_edge (test_bb), single_succ_edge (bb)->dest); + profile_probability right_prob = profile_probability::never (); + if (node->m_right) + right_prob = node->m_right->m_c->m_subtree_prob; + p = ((right_prob + default_prob / parts) + / (node->m_c->m_subtree_prob + default_prob)); + test_bb->count = bb->count.apply_probability (p); - profile_probability right_prob = profile_probability::never (); - if (node->m_right) - right_prob = node->m_right->m_c->m_subtree_prob; - p = ((right_prob + default_prob / 2) - / (node->m_c->m_subtree_prob + default_prob)); + bb = emit_cmp_and_jump_insns (bb, index, node->m_c->get_high (), + GT_EXPR, test_bb, p, loc); - bb = emit_cmp_and_jump_insns (bb, index, node->m_c->get_high (), - GT_EXPR, test_bb, p, loc); - default_prob /= 2; + default_prob /= parts; + node->m_c->m_subtree_prob -= right_prob; + if (is_bt) + node->m_c->m_default_prob = default_prob; /* Value belongs to this node or to the left-hand subtree. */ p = node->m_c->m_prob / (node->m_c->m_subtree_prob + default_prob); diff --git a/gcc/tree-switch-conversion.h b/gcc/tree-switch-conversion.h index 6861572fb17..431cf1add46 100644 --- a/gcc/tree-switch-conversion.h +++ b/gcc/tree-switch-conversion.h @@ -102,6 +102,10 @@ public: /* Probability of reaching subtree rooted at this node. */ profile_probability m_subtree_prob; + /* Probability of default case when reaching the node. + It is used by bit-test right now. */ + profile_probability m_default_prob; + protected: /* Default constructor. */ cluster () {} @@ -110,7 +114,8 @@ protected: cluster::cluster (tree case_label_expr, basic_block case_bb, profile_probability prob, profile_probability subtree_prob): m_case_label_expr (case_label_expr), m_case_bb (case_bb), m_prob (prob), - m_subtree_prob (subtree_prob) + m_subtree_prob (subtree_prob), + m_default_prob (profile_probability::uninitialized ()) { } @@ -545,6 +550,7 @@ public: basic_block target_bb; tree label; int bits; + profile_probability prob; /* Comparison function for qsort to order bit tests by decreasing probability of execution. */