--- /dev/null 2013-11-25 16:34:39.360817680 +0100 +++ new/src/share/vm/opto/replacednodes.hpp 2014-06-03 13:54:40.081223708 +0200 @@ -0,0 +1,81 @@ +/* + * Copyright (c) 2014, 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. + * + */ + +#ifndef SHARE_VM_OPTO_REPLACEDNODES_HPP +#define SHARE_VM_OPTO_REPLACEDNODES_HPP + +#include "opto/connode.hpp" + +// During parsing, when a node is "improved", +// GraphKit::replace_in_map() is called to update the current map so +// that the improved node is used from that point +// on. GraphKit::replace_in_map() doesn't operate on the callers maps +// and so some optimization opportunities may be lost. The +// ReplacedNodes class addresses that problem. +// +// A ReplacedNodes object is a list of pair of nodes. Every +// SafePointNode carries a ReplacedNodes object. Every time +// GraphKit::replace_in_map() is called, a new pair of nodes is pushed +// on the list of replaced nodes. When control flow paths merge, their +// replaced nodes are also merged. When parsing exits a method to +// return to a caller, the replaced nodes on the exit path are used to +// update the caller's map. +class ReplacedNodes VALUE_OBJ_CLASS_SPEC { + private: + class ReplacedNode VALUE_OBJ_CLASS_SPEC { + private: + Node* _initial; + Node* _improved; + public: + ReplacedNode() : _initial(NULL), _improved(NULL) {} + ReplacedNode(Node* initial, Node* improved) : _initial(initial), _improved(improved) {} + Node* initial() const { return _initial; } + Node* improved() const { return _improved; } + + bool operator==(const ReplacedNode& other) { + return _initial == other._initial && _improved == other._improved; + } + }; + GrowableArray* _replaced_nodes; + + void allocate_if_necessary(); + bool has_node(const ReplacedNode& r) const; + bool has_target_node(Node* n) const; + + public: + ReplacedNodes() + : _replaced_nodes(NULL) {} + + void clone(); + void record(Node* initial, Node* improved); + void transfer_from(const ReplacedNodes& other, uint idx); + void reset(); + void apply(Node* n); + void merge_with(const ReplacedNodes& other); + bool is_empty() const; + void dump(outputStream *st) const; + void apply(Compile* C, Node* ctl); +}; + +#endif // SHARE_VM_OPTO_REPLACEDNODES_HPP