duke@435: /*
stefank@2314:  * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
stefank@2314: #include "precompiled.hpp"
stefank@2314: #include "ci/ciConstantPoolCache.hpp"
stefank@2314: #include "ci/ciUtilities.hpp"
stefank@2314: #include "memory/allocation.hpp"
stefank@2314: #include "memory/allocation.inline.hpp"
duke@435: 
duke@435: // ciConstantPoolCache
duke@435: //
duke@435: // This class caches indexed constant pool lookups.
duke@435: 
duke@435: // ------------------------------------------------------------------
duke@435: // ciConstantPoolCache::ciConstantPoolCache
duke@435: ciConstantPoolCache::ciConstantPoolCache(Arena* arena,
duke@435:                                  int expected_size) {
duke@435:   _elements =
duke@435:     new (arena) GrowableArray<void*>(arena, expected_size, 0, 0);
duke@435:   _keys = new (arena) GrowableArray<intptr_t>(arena, expected_size, 0, 0);
duke@435: }
duke@435: 
duke@435: // ------------------------------------------------------------------
duke@435: // ciConstantPoolCache::get
duke@435: //
duke@435: // Get the entry at some index
duke@435: void* ciConstantPoolCache::get(int index) {
duke@435:   ASSERT_IN_VM;
duke@435:   int pos = find(index);
duke@435:   if (pos >= _keys->length() ||
duke@435:       _keys->at(pos) != index) {
duke@435:     // This element is not present in the cache.
duke@435:     return NULL;
duke@435:   }
duke@435:   return _elements->at(pos);
duke@435: }
duke@435: 
duke@435: // ------------------------------------------------------------------
duke@435: // ciConstantPoolCache::find
duke@435: //
duke@435: // Use binary search to find the position of this index in the cache.
duke@435: // If there is no entry in the cache corresponding to this oop, return
duke@435: // the position at which the index would be inserted.
duke@435: int ciConstantPoolCache::find(int key) {
duke@435:   int min = 0;
duke@435:   int max = _keys->length()-1;
duke@435: 
duke@435:   while (max >= min) {
duke@435:     int mid = (max + min) / 2;
duke@435:     int value = _keys->at(mid);
duke@435:     if (value < key) {
duke@435:       min = mid + 1;
duke@435:     } else if (value > key) {
duke@435:       max = mid - 1;
duke@435:     } else {
duke@435:       return mid;
duke@435:     }
duke@435:   }
duke@435:   return min;
duke@435: }
duke@435: 
duke@435: // ------------------------------------------------------------------
duke@435: // ciConstantPoolCache::insert
duke@435: //
duke@435: // Insert a ciObject into the table at some index.
duke@435: void ciConstantPoolCache::insert(int index, void* elem) {
duke@435:   int i;
duke@435:   int pos = find(index);
duke@435:   for (i = _keys->length()-1; i >= pos; i--) {
duke@435:     _keys->at_put_grow(i+1, _keys->at(i));
duke@435:     _elements->at_put_grow(i+1, _elements->at(i));
duke@435:   }
duke@435:   _keys->at_put_grow(pos, index);
duke@435:   _elements->at_put_grow(pos, elem);
duke@435: }
duke@435: 
duke@435: // ------------------------------------------------------------------
duke@435: // ciConstantPoolCache::print
duke@435: //
duke@435: // Print debugging information about the cache.
duke@435: void ciConstantPoolCache::print() {
duke@435:   Unimplemented();
duke@435: }