IBM Z: Fix usage of "f" constraint with long doubles

[official-gcc.git] / gcc / analyzer / state-purge.cc

/* Classes for purging state at function_points.
   Copyright (C) 2019-2021 Free Software Foundation, Inc.
   Contributed by David Malcolm <dmalcolm@redhat.com>.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.

GCC is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tree.h"
#include "timevar.h"
#include "tree-ssa-alias.h"
#include "function.h"
#include "basic-block.h"
#include "gimple.h"
#include "stringpool.h"
#include "tree-vrp.h"
#include "gimple-ssa.h"
#include "tree-ssanames.h"
#include "tree-phinodes.h"
#include "options.h"
#include "ssa-iterators.h"
#include "diagnostic-core.h"
#include "gimple-pretty-print.h"
#include "function.h"
#include "json.h"
#include "analyzer/analyzer.h"
#include "analyzer/call-string.h"
#include "digraph.h"
#include "ordered-hash-map.h"
#include "cfg.h"
#include "gimple-iterator.h"
#include "cgraph.h"
#include "analyzer/supergraph.h"
#include "analyzer/program-point.h"
#include "analyzer/analyzer-logging.h"
#include "analyzer/state-purge.h"

#if ENABLE_ANALYZER

/* state_purge_map's ctor.  Walk all SSA names in all functions, building
   a state_purge_per_ssa_name instance for each.  */

state_purge_map::state_purge_map (const supergraph &sg,
                                  logger *logger)
: log_user (logger), m_sg (sg)
{
  LOG_FUNC (logger);

  auto_timevar tv (TV_ANALYZER_STATE_PURGE);

  cgraph_node *node;
  FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node)
  {
    function *fun = node->get_fun ();
    if (logger)
      log ("function: %s", function_name (fun));
    tree name;
    unsigned int i;;
    FOR_EACH_SSA_NAME (i, name, fun)
      {
        /* For now, don't bother tracking the .MEM SSA names.  */
        if (tree var = SSA_NAME_VAR (name))
          if (TREE_CODE (var) == VAR_DECL)
            if (VAR_DECL_IS_VIRTUAL_OPERAND (var))
              continue;
        m_map.put (name, new state_purge_per_ssa_name (*this, name, fun));
      }
  }
}

/* state_purge_map's dtor.  */

state_purge_map::~state_purge_map ()
{
  for (iterator iter = m_map.begin (); iter != m_map.end (); ++iter)
    delete (*iter).second;
}

/* state_purge_per_ssa_name's ctor.

   Locate all uses of VAR within FUN.
   Walk backwards from each use, marking program points, until
   we reach the def stmt, populating m_points_needing_var.

   We have to track program points rather than
   just stmts since there could be empty basic blocks on the way.  */

state_purge_per_ssa_name::state_purge_per_ssa_name (const state_purge_map &map,
                                                    tree name,
                                                    function *fun)
: m_points_needing_name (), m_name (name), m_fun (fun)
{
  LOG_FUNC (map.get_logger ());

  if (map.get_logger ())
    {
      map.log ("SSA name: %qE within %qD", name, fun->decl);

      /* Show def stmt.  */
      const gimple *def_stmt = SSA_NAME_DEF_STMT (name);
      pretty_printer pp;
      pp_gimple_stmt_1 (&pp, def_stmt, 0, (dump_flags_t)0);
      map.log ("def stmt: %s", pp_formatted_text (&pp));
    }

  auto_vec<function_point> worklist;

  /* Add all immediate uses of name to the worklist.
     Compare with debug_immediate_uses.  */
  imm_use_iterator iter;
  use_operand_p use_p;
  FOR_EACH_IMM_USE_FAST (use_p, iter, name)
    {
      if (USE_STMT (use_p))
        {
          const gimple *use_stmt = USE_STMT (use_p);
          if (map.get_logger ())
            {
              pretty_printer pp;
              pp_gimple_stmt_1 (&pp, use_stmt, 0, (dump_flags_t)0);
              map.log ("used by stmt: %s", pp_formatted_text (&pp));
            }

          const supernode *snode
            = map.get_sg ().get_supernode_for_stmt (use_stmt);

          /* If it's a use within a phi node, then we care about
             which in-edge we came from.  */
          if (use_stmt->code == GIMPLE_PHI)
            {
              for (gphi_iterator gpi
                     = const_cast<supernode *> (snode)->start_phis ();
                   !gsi_end_p (gpi); gsi_next (&gpi))
                {
                  gphi *phi = gpi.phi ();
                  if (phi == use_stmt)
                    {
                      /* Find arguments (and thus in-edges) which use NAME.  */
                      for (unsigned arg_idx = 0;
                           arg_idx < gimple_phi_num_args (phi);
                           ++arg_idx)
                        {
                          if (name == gimple_phi_arg (phi, arg_idx)->def)
                            {
                              edge in_edge = gimple_phi_arg_edge (phi, arg_idx);
                              const superedge *in_sedge
                                = map.get_sg ().get_edge_for_cfg_edge (in_edge);
                              function_point point
                                = function_point::before_supernode
                                (snode, in_sedge);
                              add_to_worklist (point, &worklist,
                                               map.get_logger ());
                              m_points_needing_name.add (point);
                            }
                        }
                    }
                }
            }
          else
            {
              function_point point = before_use_stmt (map, use_stmt);
              add_to_worklist (point, &worklist, map.get_logger ());
              m_points_needing_name.add (point);

              /* We also need to add uses for conditionals and switches,
                 where the stmt "happens" at the after_supernode, for filtering
                 the out-edges.  */
              if (use_stmt == snode->get_last_stmt ())
                {
                  if (map.get_logger ())
                    map.log ("last stmt in BB");
                  function_point point
                    = function_point::after_supernode (snode);
                  add_to_worklist (point, &worklist, map.get_logger ());
                  m_points_needing_name.add (point);
                }
              else
                if (map.get_logger ())
                  map.log ("not last stmt in BB");
            }
        }
    }

  /* Process worklist by walking backwards until we reach the def stmt.  */
  {
    log_scope s (map.get_logger (), "processing worklist");
    while (worklist.length () > 0)
      {
        function_point point = worklist.pop ();
        process_point (point, &worklist, map);
    }
  }

  if (map.get_logger ())
    {
      map.log ("%qE in %qD is needed to process:", name, fun->decl);
      /* Log m_points_needing_name, sorting it to avoid churn when comparing
         dumps.  */
      auto_vec<function_point> points;
      for (point_set_t::iterator iter = m_points_needing_name.begin ();
           iter != m_points_needing_name.end ();
           ++iter)
        points.safe_push (*iter);
      points.qsort (function_point::cmp_ptr);
      unsigned i;
      function_point *point;
      FOR_EACH_VEC_ELT (points, i, point)
        {
          map.start_log_line ();
          map.get_logger ()->log_partial ("  point: ");
          point->print (map.get_logger ()->get_printer (), format (false));
          map.end_log_line ();
        }
    }
}

/* Return true if the SSA name is needed at POINT.  */

bool
state_purge_per_ssa_name::needed_at_point_p (const function_point &point) const
{
  return const_cast <point_set_t &> (m_points_needing_name).contains (point);
}

/* Get the function_point representing immediately before USE_STMT.
   Subroutine of ctor.  */

function_point
state_purge_per_ssa_name::before_use_stmt (const state_purge_map &map,
                                           const gimple *use_stmt)
{
  gcc_assert (use_stmt->code != GIMPLE_PHI);

  const supernode *supernode
    = map.get_sg ().get_supernode_for_stmt (use_stmt);
  unsigned int stmt_idx = supernode->get_stmt_index (use_stmt);
  return function_point::before_stmt (supernode, stmt_idx);
}

/* Add POINT to *WORKLIST if the point has not already been seen.
   Subroutine of ctor.  */

void
state_purge_per_ssa_name::add_to_worklist (const function_point &point,
                                           auto_vec<function_point> *worklist,
                                           logger *logger)
{
  LOG_FUNC (logger);
  if (logger)
    {
      logger->start_log_line ();
      logger->log_partial ("point: '");
      point.print (logger->get_printer (), format (false));
      logger->log_partial ("' for worklist for %qE", m_name);
      logger->end_log_line ();
    }

  gcc_assert (point.get_function () == m_fun);
  if (point.get_from_edge ())
    gcc_assert (point.get_from_edge ()->get_kind () == SUPEREDGE_CFG_EDGE);

  if (m_points_needing_name.contains (point))
    {
      if (logger)
        logger->log ("already seen for %qE", m_name);
    }
  else
    {
      if (logger)
        logger->log ("not seen; adding to worklist for %qE", m_name);
      m_points_needing_name.add (point);
      worklist->safe_push (point);
    }
}

/* Process POINT, popped from WORKLIST.
   Iterate over predecessors of POINT, adding to WORKLIST.  */

void
state_purge_per_ssa_name::process_point (const function_point &point,
                                         auto_vec<function_point> *worklist,
                                         const state_purge_map &map)
{
  logger *logger = map.get_logger ();
  LOG_FUNC (logger);
  if (logger)
    {
      logger->start_log_line ();
      logger->log_partial ("considering point: '");
      point.print (logger->get_printer (), format (false));
      logger->log_partial ("' for %qE", m_name);
      logger->end_log_line ();
    }

  gimple *def_stmt = SSA_NAME_DEF_STMT (m_name);

  const supernode *snode = point.get_supernode ();

  switch (point.get_kind ())
    {
    default:
      gcc_unreachable ();

    case PK_ORIGIN:
      break;

    case PK_BEFORE_SUPERNODE:
      {
        for (gphi_iterator gpi
               = const_cast<supernode *> (snode)->start_phis ();
             !gsi_end_p (gpi); gsi_next (&gpi))
          {
            gphi *phi = gpi.phi ();
            if (phi == def_stmt)
              {
                if (logger)
                  logger->log ("def stmt within phis; terminating");
                return;
              }
          }

        /* Add given pred to worklist.  */
        if (point.get_from_edge ())
          {
            gcc_assert (point.get_from_edge ()->m_src);
            add_to_worklist
              (function_point::after_supernode (point.get_from_edge ()->m_src),
               worklist, logger);
          }
        else
          {
            /* Add any intraprocedually edge for a call.  */
            if (snode->m_returning_call)
              {
                cgraph_edge *cedge
                  = supergraph_call_edge (snode->m_fun,
                                          snode->m_returning_call);
                gcc_assert (cedge);
                superedge *sedge
                  = map.get_sg ().get_intraprocedural_edge_for_call (cedge);
                gcc_assert (sedge);
                add_to_worklist
                  (function_point::after_supernode (sedge->m_src),
                   worklist, logger);
              }
          }
      }
      break;

    case PK_BEFORE_STMT:
      {
        if (def_stmt == point.get_stmt ())
          {
            if (logger)
              logger->log ("def stmt; terminating");
            return;
          }
        if (point.get_stmt_idx () > 0)
          add_to_worklist (function_point::before_stmt
                             (snode, point.get_stmt_idx () - 1),
                           worklist, logger);
        else
        {
          /* Add before_supernode to worklist.  This captures the in-edge,
             so we have to do it once per in-edge.  */
          unsigned i;
          superedge *pred;
          FOR_EACH_VEC_ELT (snode->m_preds, i, pred)
            add_to_worklist (function_point::before_supernode (snode,
                                                               pred),
                             worklist, logger);
        }
      }
      break;

    case PK_AFTER_SUPERNODE:
      {
        if (snode->m_stmts.length ())
          add_to_worklist
            (function_point::before_stmt (snode,
                                          snode->m_stmts.length () - 1),
             worklist, logger);
        else
          {
            /* Add before_supernode to worklist.  This captures the in-edge,
               so we have to do it once per in-edge.  */
            unsigned i;
            superedge *pred;
            FOR_EACH_VEC_ELT (snode->m_preds, i, pred)
              add_to_worklist (function_point::before_supernode (snode,
                                                                 pred),
                               worklist, logger);
            /* If it's the initial BB, add it, to ensure that we
               have "before supernode" for the initial ENTRY block, and don't
               erroneously purge SSA names for initial values of parameters.  */
            if (snode->entry_p ())
              {
                add_to_worklist
                  (function_point::before_supernode (snode, NULL),
                   worklist, logger);
              }
          }
      }
      break;
    }
}

/* class state_purge_annotator : public dot_annotator.  */

/* Implementation of dot_annotator::add_node_annotations vfunc for
   state_purge_annotator.

   Add an additional record showing which names are purged on entry
   to the supernode N.  */

bool
state_purge_annotator::add_node_annotations (graphviz_out *gv,
                                             const supernode &n,
                                             bool within_table) const
{
  if (m_map == NULL)
    return false;

  if (within_table)
    return false;

  pretty_printer *pp = gv->get_pp ();

   pp_printf (pp, "annotation_for_node_%i", n.m_index);
   pp_printf (pp, " [shape=none,margin=0,style=filled,fillcolor=%s,label=\"",
              "lightblue");
   pp_write_text_to_stream (pp);

   // FIXME: passing in a NULL in-edge means we get no hits
   function_point before_supernode
     (function_point::before_supernode (&n, NULL));

   for (state_purge_map::iterator iter = m_map->begin ();
        iter != m_map->end ();
        ++iter)
     {
       tree name = (*iter).first;
       state_purge_per_ssa_name *per_name_data = (*iter).second;
       if (per_name_data->get_function () == n.m_fun)
         {
           if (per_name_data->needed_at_point_p (before_supernode))
             pp_printf (pp, "%qE needed here", name);
           else
             pp_printf (pp, "%qE not needed here", name);
         }
       pp_newline (pp);
     }

   pp_string (pp, "\"];\n\n");
   pp_flush (pp);
   return false;
}

/* Print V to GV as a comma-separated list in braces within a <TR>,
   titling it with TITLE.

   Subroutine of state_purge_annotator::add_stmt_annotations.  */

static void
print_vec_of_names (graphviz_out *gv, const char *title,
                    const auto_vec<tree> &v)
{
  pretty_printer *pp = gv->get_pp ();
  tree name;
  unsigned i;
  gv->begin_trtd ();
  pp_printf (pp, "%s: {", title);
  FOR_EACH_VEC_ELT (v, i, name)
    {
      if (i > 0)
        pp_string (pp, ", ");
      pp_printf (pp, "%qE", name);
    }
  pp_printf (pp, "}");
  pp_write_text_as_html_like_dot_to_stream (pp);
  gv->end_tdtr ();
  pp_newline (pp);
}

/* Implementation of dot_annotator::add_stmt_annotations for
   state_purge_annotator.

   Add text showing which names are purged at STMT.  */

void
state_purge_annotator::add_stmt_annotations (graphviz_out *gv,
                                             const gimple *stmt,
                                             bool within_row) const
{
  if (within_row)
    return;

  if (m_map == NULL)
    return;

  if (stmt->code == GIMPLE_PHI)
    return;

  pretty_printer *pp = gv->get_pp ();

  pp_newline (pp);

  const supernode *supernode = m_map->get_sg ().get_supernode_for_stmt (stmt);
  unsigned int stmt_idx = supernode->get_stmt_index (stmt);
  function_point before_stmt
    (function_point::before_stmt (supernode, stmt_idx));

  auto_vec<tree> needed;
  auto_vec<tree> not_needed;
  for (state_purge_map::iterator iter = m_map->begin ();
       iter != m_map->end ();
       ++iter)
    {
      tree name = (*iter).first;
      state_purge_per_ssa_name *per_name_data = (*iter).second;
      if (per_name_data->get_function () == supernode->m_fun)
        {
          if (per_name_data->needed_at_point_p (before_stmt))
            needed.safe_push (name);
          else
            not_needed.safe_push (name);
        }
    }

  print_vec_of_names (gv, "needed here", needed);
  print_vec_of_names (gv, "not needed here", not_needed);
}

#endif /* #if ENABLE_ANALYZER */