1 /*
2  * Copyright (C) 2014 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ART_COMPILER_OPTIMIZING_CONSTANT_FOLDING_H_
18 #define ART_COMPILER_OPTIMIZING_CONSTANT_FOLDING_H_
19 
20 #include "nodes.h"
21 #include "optimization.h"
22 
23 namespace art {
24 
25 /**
26  * Optimization pass performing a simple constant-expression
27  * evaluation on the SSA form.
28  *
29  * Note that graph simplifications producing a constant should be
30  * implemented in art::HConstantFolding, while graph simplifications
31  * not producing constants should be implemented in
32  * art::InstructionSimplifier.  (This convention is a choice that was
33  * made during the development of these parts of the compiler and is
34  * not bound by any technical requirement.)
35  *
36  * This class is named art::HConstantFolding to avoid name
37  * clashes with the art::ConstantPropagation class defined in
38  * compiler/dex/post_opt_passes.h.
39  */
40 class HConstantFolding : public HOptimization {
41  public:
HConstantFolding(HGraph * graph,const char * name)42   HConstantFolding(HGraph* graph, const char* name) : HOptimization(graph, name) {}
43 
44   void Run() OVERRIDE;
45 
46   static constexpr const char* kConstantFoldingPassName = "constant_folding";
47 
48  private:
49   DISALLOW_COPY_AND_ASSIGN(HConstantFolding);
50 };
51 
52 }  // namespace art
53 
54 #endif  // ART_COMPILER_OPTIMIZING_CONSTANT_FOLDING_H_
55