1 /* A class to encapsulate decisions about how the analysis should happen. 2 Copyright (C) 2019-2020 Free Software Foundation, Inc. 3 Contributed by David Malcolm <dmalcolm@redhat.com>. 4 5 This file is part of GCC. 6 7 GCC is free software; you can redistribute it and/or modify it 8 under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3, or (at your option) 10 any later version. 11 12 GCC is distributed in the hope that it will be useful, but 13 WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with GCC; see the file COPYING3. If not see 19 <http://www.gnu.org/licenses/>. */ 20 21 #include "config.h" 22 #include "system.h" 23 #include "coretypes.h" 24 #include "tree.h" 25 #include "options.h" 26 #include "cgraph.h" 27 #include "timevar.h" 28 #include "ipa-utils.h" 29 #include "function.h" 30 #include "analyzer/analyzer.h" 31 #include "diagnostic-core.h" 32 #include "analyzer/analyzer-logging.h" 33 #include "analyzer/analysis-plan.h" 34 #include "ordered-hash-map.h" 35 #include "options.h" 36 #include "cgraph.h" 37 #include "function.h" 38 #include "cfg.h" 39 #include "basic-block.h" 40 #include "gimple.h" 41 #include "gimple-iterator.h" 42 #include "digraph.h" 43 #include "analyzer/supergraph.h" 44 45 #if ENABLE_ANALYZER 46 47 /* class analysis_plan. */ 48 49 /* analysis_plan's ctor. */ 50 51 analysis_plan::analysis_plan (const supergraph &sg, logger *logger) 52 : log_user (logger), m_sg (sg), 53 m_cgraph_node_postorder (XCNEWVEC (struct cgraph_node *, 54 symtab->cgraph_count)), 55 m_index_by_uid (symtab->cgraph_max_uid) 56 { 57 LOG_SCOPE (logger); 58 auto_timevar time (TV_ANALYZER_PLAN); 59 60 m_num_cgraph_nodes = ipa_reverse_postorder (m_cgraph_node_postorder); 61 gcc_assert (m_num_cgraph_nodes == symtab->cgraph_count); 62 if (get_logger_file ()) 63 ipa_print_order (get_logger_file (), 64 "analysis_plan", m_cgraph_node_postorder, 65 m_num_cgraph_nodes); 66 67 /* Populate m_index_by_uid. */ 68 for (int i = 0; i < symtab->cgraph_max_uid; i++) 69 m_index_by_uid.quick_push (-1); 70 for (int i = 0; i < m_num_cgraph_nodes; i++) 71 { 72 gcc_assert (m_cgraph_node_postorder[i]->get_uid () 73 < symtab->cgraph_max_uid); 74 m_index_by_uid[m_cgraph_node_postorder[i]->get_uid ()] = i; 75 } 76 } 77 78 /* analysis_plan's dtor. */ 79 80 analysis_plan::~analysis_plan () 81 { 82 free (m_cgraph_node_postorder); 83 } 84 85 /* Comparator for use by the exploded_graph's worklist, to order FUN_A 86 and FUN_B so that functions that are to be summarized are visited 87 before the summary is needed (based on a sort of the callgraph). */ 88 89 int 90 analysis_plan::cmp_function (function *fun_a, function *fun_b) const 91 { 92 cgraph_node *node_a = cgraph_node::get (fun_a->decl); 93 cgraph_node *node_b = cgraph_node::get (fun_b->decl); 94 95 int idx_a = m_index_by_uid[node_a->get_uid ()]; 96 int idx_b = m_index_by_uid[node_b->get_uid ()]; 97 98 return idx_b - idx_a; 99 } 100 101 /* Return true if the call EDGE should be analyzed using a call summary. 102 Return false if it should be analyzed using a full call and return. */ 103 104 bool 105 analysis_plan::use_summary_p (const cgraph_edge *edge) const 106 { 107 /* Don't use call summaries if -fno-analyzer-call-summaries. */ 108 if (!flag_analyzer_call_summaries) 109 return false; 110 111 /* TODO: don't count callsites each time. */ 112 int num_call_sites = 0; 113 const cgraph_node *callee = edge->callee; 114 for (cgraph_edge *edge = callee->callers; edge; edge = edge->next_caller) 115 ++num_call_sites; 116 117 /* Don't use a call summary if there's only one call site. */ 118 if (num_call_sites <= 1) 119 return false; 120 121 /* Require the callee to be sufficiently complex to be worth 122 summarizing. */ 123 const function *fun 124 = const_cast <cgraph_node *> (callee)->ultimate_alias_target ()->get_fun (); 125 /* TODO(stage1): can ultimate_alias_target be made const? */ 126 127 if ((int)m_sg.get_num_snodes (fun) 128 < param_analyzer_min_snodes_for_call_summary) 129 return false; 130 131 return true; 132 } 133 134 #endif /* #if ENABLE_ANALYZER */ 135