Quellcode-Bibliothek

^© Kompilation durch diese Firma

[Weder Korrektheit noch Funktionsfähigkeit der Software werden zugesichert.]

Datei: narrowptrnode.hpp Sprache: C

/*
* Copyright (c) 2016, 2022, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/

#include "precompiled.hpp"
#include "memory/resourceArea.hpp"
#include "opto/cfgnode.hpp"
#include "opto/phaseX.hpp"
#include "opto/replacednodes.hpp"

void ReplacedNodes::allocate_if_necessary() {
  if (_replaced_nodes == NULL) {
    _replaced_nodes = new GrowableArray<ReplacedNode>();
  }
}

bool ReplacedNodes::is_empty() const {
  return _replaced_nodes == NULL || _replaced_nodes->length() == 0;
}

bool ReplacedNodes::has_node(const ReplacedNode& r) const {
  return _replaced_nodes->find(r) != -1;
}

bool ReplacedNodes::has_target_node(Node* n) const {
  for (int i = 0; i < _replaced_nodes->length(); i++) {
    if (_replaced_nodes->at(i).improved() == n) {
      return true;
    }
  }
  return false;
}

// Record replaced node if not seen before
void ReplacedNodes::record(Node* initial, Node* improved) {
  allocate_if_necessary();
  ReplacedNode r(initial, improved);
  if (!has_node(r)) {
    _replaced_nodes->push(r);
  }
}

// Copy replaced nodes from one map to another. idx is used to
// identify nodes that are too new to be of interest in the target
// node list.
void ReplacedNodes::transfer_from(const ReplacedNodes& other, uint idx) {
  if (other.is_empty()) {
    return;
  }
  allocate_if_necessary();
  for (int i = 0; i < other._replaced_nodes->length(); i++) {
    ReplacedNode replaced = other._replaced_nodes->at(i);
    // Only transfer the nodes that can actually be useful
    if (!has_node(replaced) && (replaced.initial()->_idx < idx || has_target_node(replaced.initial()))) {
      _replaced_nodes->push(replaced);
    }
  }
}

void ReplacedNodes::clone() {
  if (_replaced_nodes != NULL) {
    GrowableArray<ReplacedNode>* replaced_nodes_clone = new GrowableArray<ReplacedNode>();
    replaced_nodes_clone->appendAll(_replaced_nodes);
    _replaced_nodes = replaced_nodes_clone;
  }
}

void ReplacedNodes::reset() {
  if (_replaced_nodes != NULL) {
    _replaced_nodes->clear();
  }
}

// Perform node replacement (used when returning to caller)
void ReplacedNodes::apply(Node* n, uint idx) {
  if (is_empty()) {
    return;
  }
  for (int i = 0; i < _replaced_nodes->length(); i++) {
    ReplacedNode replaced = _replaced_nodes->at(i);
    // Only apply if improved node was created in a callee to avoid
    // issues with irreducible loops in the caller
    if (replaced.improved()->_idx >= idx) {
      n->replace_edge(replaced.initial(), replaced.improved());
    }
  }
}

static void enqueue_use(Node* n, Node* use, Unique_Node_List& work) {
  if (use->is_Phi()) {
    Node* r = use->in(0);
    assert(r->is_Region(), "Phi should have Region");
    for (uint i = 1; i < use->req(); i++) {
      if (use->in(i) == n) {
        work.push(r->in(i));
      }
    }
  } else {
    work.push(use);
  }
}

// Perform node replacement following late inlining.
void ReplacedNodes::apply(Compile* C, Node* ctl) {
  // ctl is the control on exit of the method that was late inlined
  if (is_empty()) {
    return;
  }
  for (int i = 0; i < _replaced_nodes->length(); i++) {
    ReplacedNode replaced = _replaced_nodes->at(i);
    Node* initial = replaced.initial();
    Node* improved = replaced.improved();
    assert (ctl != NULL && !ctl->is_top(), "replaced node should have actual control");

    ResourceMark rm;
    Unique_Node_List work;
    // Go over all the uses of the node that is considered for replacement...
    for (DUIterator j = initial->outs(); initial->has_out(j); j++) {
      Node* use = initial->out(j);

      if (use == improved || use->outcnt() == 0) {
        continue;
      }
      work.clear();
      enqueue_use(initial, use, work);
      bool replace = true;
      // Check that this use is dominated by ctl. Go ahead with the replacement if it is.
      while (work.size() != 0 && replace) {
        Node* n = work.pop();
        if (use->outcnt() == 0) {
          continue;
        }
        if (n->is_CFG() || (n->in(0) != NULL && !n->in(0)->is_top())) {
          // Skip projections, since some of the multi nodes aren't CFG (e.g., LoadStore and SCMemProj).
          if (n->is_Proj()) {
            n = n->in(0);
          }
          if (!n->is_CFG()) {
            n = n->in(0);
          }
          assert(n->is_CFG(), "should be CFG now");
          int depth = 0;
          while(n != ctl) {
            n = IfNode::up_one_dom(n);
            depth++;
            // limit search depth
            if (depth >= 100 || n == NULL) {
              replace = false;
              break;
            }
          }
        } else {
          for (DUIterator k = n->outs(); n->has_out(k); k++) {
            enqueue_use(n, n->out(k), work);
          }
        }
      }
      if (replace) {
        bool is_in_table = C->initial_gvn()->hash_delete(use);
        int replaced = use->replace_edge(initial, improved);
        if (is_in_table) {
          C->initial_gvn()->hash_find_insert(use);
        }
        C->record_for_igvn(use);

        assert(replaced > 0, "inconsistent");
        --j;
      }
    }
  }
}

void ReplacedNodes::dump(outputStream *st) const {
  if (!is_empty()) {
    st->print("replaced nodes: ");
    for (int i = 0; i < _replaced_nodes->length(); i++) {
      st->print("%d->%d", _replaced_nodes->at(i).initial()->_idx, _replaced_nodes->at(i).improved()->_idx);
      if (i < _replaced_nodes->length()-1) {
        st->print(",");
      }
    }
  }
}

// Merge 2 list of replaced node at a point where control flow paths merge
void ReplacedNodes::merge_with(const ReplacedNodes& other) {
  if (is_empty()) {
    return;
  }
  if (other.is_empty()) {
    reset();
    return;
  }
  int shift = 0;
  int len = _replaced_nodes->length();
  for (int i = 0; i < len; i++) {
    if (!other.has_node(_replaced_nodes->at(i))) {
      shift++;
    } else if (shift > 0) {
      _replaced_nodes->at_put(i-shift, _replaced_nodes->at(i));
    }
  }
  if (shift > 0) {
    _replaced_nodes->trunc_to(len - shift);
  }
}

¤ Dauer der Verarbeitung: 0.33 Sekunden (vorverarbeitet) ¤

Druckansicht unsichere Verbindung
Druckansicht sprechenden Kalenders
in der Quellcodebibliothek suchen

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.