Line data    Source code

       1              : /* A class to encapsulate decisions about how the analysis should happen.
       2              :    Copyright (C) 2019-2026 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 "analyzer/common.h"
      22              : 
      23              : #include "timevar.h"
      24              : #include "ordered-hash-map.h"
      25              : #include "options.h"
      26              : #include "cgraph.h"
      27              : #include "cfg.h"
      28              : #include "gimple-iterator.h"
      29              : #include "digraph.h"
      30              : #include "ipa-utils.h"
      31              : 
      32              : #include "analyzer/analyzer-logging.h"
      33              : #include "analyzer/analysis-plan.h"
      34              : #include "analyzer/supergraph.h"
      35              : 
      36              : #if ENABLE_ANALYZER
      37              : 
      38              : /* class analysis_plan.  */
      39              : 
      40              : /* analysis_plan's ctor.  */
      41              : 
      42         3377 : analysis_plan::analysis_plan (const supergraph &sg, logger *logger)
      43         3377 : : log_user (logger), m_sg (sg),
      44         3377 :   m_cgraph_node_postorder (XCNEWVEC (struct cgraph_node *,
      45              :                                      symtab->cgraph_count)),
      46         6754 :   m_index_by_uid (symtab->cgraph_max_uid)
      47              : {
      48         3377 :   LOG_SCOPE (logger);
      49         3377 :   auto_timevar time (TV_ANALYZER_PLAN);
      50              : 
      51         3377 :   m_num_cgraph_nodes = ipa_reverse_postorder (m_cgraph_node_postorder);
      52         3377 :   gcc_assert (m_num_cgraph_nodes == symtab->cgraph_count);
      53         3377 :   if (get_logger_file ())
      54            5 :     ipa_print_order (get_logger_file (),
      55              :                      "analysis_plan", m_cgraph_node_postorder,
      56              :                      m_num_cgraph_nodes);
      57              : 
      58              :   /* Populate m_index_by_uid.  */
      59        89770 :   for (int i = 0; i < symtab->cgraph_max_uid; i++)
      60        86393 :     m_index_by_uid.quick_push (-1);
      61        21190 :   for (int i = 0; i < m_num_cgraph_nodes; i++)
      62              :     {
      63        17813 :       gcc_assert (m_cgraph_node_postorder[i]->get_uid ()
      64              :                   < symtab->cgraph_max_uid);
      65        17813 :       m_index_by_uid[m_cgraph_node_postorder[i]->get_uid ()] = i;
      66              :     }
      67         3377 : }
      68              : 
      69              : /* analysis_plan's dtor.  */
      70              : 
      71         3377 : analysis_plan::~analysis_plan ()
      72              : {
      73         3377 :   free (m_cgraph_node_postorder);
      74         3377 : }
      75              : 
      76              : /* Comparator for use by the exploded_graph's worklist, to order FUN_A
      77              :    and FUN_B so that functions that are to be summarized are visited
      78              :    before the summary is needed (based on a sort of the callgraph).  */
      79              : 
      80              : int
      81        50107 : analysis_plan::cmp_function (function *fun_a, function *fun_b) const
      82              : {
      83        50107 :   cgraph_node *node_a = cgraph_node::get (fun_a->decl);
      84        50107 :   cgraph_node *node_b = cgraph_node::get (fun_b->decl);
      85              : 
      86        50107 :   int idx_a = m_index_by_uid[node_a->get_uid ()];
      87        50107 :   int idx_b = m_index_by_uid[node_b->get_uid ()];
      88              : 
      89        50107 :   return idx_b - idx_a;
      90              : }
      91              : 
      92              : /* Return true if the call EDGE should be analyzed using a call summary.
      93              :    Return false if it should be analyzed using a full call and return.  */
      94              : 
      95              : bool
      96         7548 : analysis_plan::use_summary_p (const cgraph_edge *edge) const
      97              : {
      98              :   /* Don't use call summaries if -fno-analyzer-call-summaries.  */
      99         7548 :   if (!flag_analyzer_call_summaries)
     100              :     return false;
     101              : 
     102              :   /* Don't use call summaries if there is no callgraph edge */
     103         1210 :   if (!edge || !edge->callee)
     104              :     return false;
     105              : 
     106              :   /* TODO: don't count callsites each time.  */
     107         1210 :   int num_call_sites = 0;
     108         1210 :   const cgraph_node *callee = edge->callee;
     109         6145 :   for (cgraph_edge *edge = callee->callers; edge; edge = edge->next_caller)
     110         4935 :     ++num_call_sites;
     111              : 
     112              :   /* Don't use a call summary if there's only one call site.  */
     113         1210 :   if (num_call_sites <= 1)
     114              :     return false;
     115              : 
     116              :   /* Require the callee to be sufficiently complex to be worth
     117              :      summarizing.  */
     118         1043 :   const function *fun
     119         1043 :     = const_cast <cgraph_node *> (callee)->ultimate_alias_target ()->get_fun ();
     120              :   /* TODO(stage1): can ultimate_alias_target be made const?  */
     121              : 
     122         1043 :   if ((int)m_sg.get_num_snodes (fun)
     123         1043 :       < param_analyzer_min_snodes_for_call_summary)
     124              :     return false;
     125              : 
     126              :   return true;
     127              : }
     128              : 
     129              : #endif /* #if ENABLE_ANALYZER */