1b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// Copyright 2014 the V8 project authors. All rights reserved. 2b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// Use of this source code is governed by a BSD-style license that can be 3b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// found in the LICENSE file. 4b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 5b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch#ifndef V8_COMPILER_GRAPH_REDUCER_H_ 6b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch#define V8_COMPILER_GRAPH_REDUCER_H_ 7b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 8b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch#include "src/zone-containers.h" 9b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 10b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochnamespace v8 { 11b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochnamespace internal { 12b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochnamespace compiler { 13b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 14b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// Forward declarations. 15b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochclass Graph; 16b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochclass Node; 17b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 18b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 19b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// Represents the result of trying to reduce a node in the graph. 20b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochclass Reduction FINAL { 21b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch public: 22b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch explicit Reduction(Node* replacement = NULL) : replacement_(replacement) {} 23b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 24b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch Node* replacement() const { return replacement_; } 25b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch bool Changed() const { return replacement() != NULL; } 26b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 27b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch private: 28b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch Node* replacement_; 29b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch}; 30b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 31b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 32b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// A reducer can reduce or simplify a given node based on its operator and 33b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// inputs. This class functions as an extension point for the graph reducer for 34b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// language-specific reductions (e.g. reduction based on types or constant 35b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// folding of low-level operators) can be integrated into the graph reduction 36b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// phase. 37b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochclass Reducer { 38b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch public: 39b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch Reducer() {} 40b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch virtual ~Reducer() {} 41b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 42b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch // Try to reduce a node if possible. 43b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch virtual Reduction Reduce(Node* node) = 0; 44b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 45b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch // Helper functions for subclasses to produce reductions for a node. 46b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch static Reduction NoChange() { return Reduction(); } 47b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch static Reduction Replace(Node* node) { return Reduction(node); } 48b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch static Reduction Changed(Node* node) { return Reduction(node); } 49b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 50b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch private: 51b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch DISALLOW_COPY_AND_ASSIGN(Reducer); 52b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch}; 53b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 54b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 55b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// Performs an iterative reduction of a node graph. 56b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochclass GraphReducer FINAL { 57b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch public: 58b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch explicit GraphReducer(Graph* graph); 59b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 60b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch Graph* graph() const { return graph_; } 61b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 62b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch void AddReducer(Reducer* reducer) { reducers_.push_back(reducer); } 63b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 64b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch // Reduce a single node. 65b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch void ReduceNode(Node* node); 66b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch // Reduce the whole graph. 67b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch void ReduceGraph(); 68b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 69b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch private: 70b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch Graph* graph_; 71b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch ZoneVector<Reducer*> reducers_; 72b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 73b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch DISALLOW_COPY_AND_ASSIGN(GraphReducer); 74b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch}; 75b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 76b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch} // namespace compiler 77b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch} // namespace internal 78b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch} // namespace v8 79b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 80b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch#endif // V8_COMPILER_GRAPH_REDUCER_H_ 81