1 /*
2  * Copyright (C) 2016 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_LINEAR_ORDER_H_
18 #define ART_COMPILER_OPTIMIZING_LINEAR_ORDER_H_
19 
20 #include <type_traits>
21 
22 #include "nodes.h"
23 
24 namespace art {
25 
26 void LinearizeGraphInternal(const HGraph* graph, ArrayRef<HBasicBlock*> linear_order);
27 
28 // Linearizes the 'graph' such that:
29 // (1): a block is always after its dominator,
30 // (2): blocks of loops are contiguous.
31 //
32 // Storage is obtained through 'allocator' and the linear order it computed
33 // into 'linear_order'. Once computed, iteration can be expressed as:
34 //
35 // for (HBasicBlock* block : linear_order)                   // linear order
36 //
37 // for (HBasicBlock* block : ReverseRange(linear_order))     // linear post order
38 //
39 template <typename Vector>
LinearizeGraph(const HGraph * graph,Vector * linear_order)40 void LinearizeGraph(const HGraph* graph, Vector* linear_order) {
41   static_assert(std::is_same<HBasicBlock*, typename Vector::value_type>::value,
42                 "Vector::value_type must be HBasicBlock*.");
43   // Resize the vector and pass an ArrayRef<> to internal implementation which is shared
44   // for all kinds of vectors, i.e. ArenaVector<> or ScopedArenaVector<>.
45   linear_order->resize(graph->GetReversePostOrder().size());
46   LinearizeGraphInternal(graph, ArrayRef<HBasicBlock*>(*linear_order));
47 }
48 
49 }  // namespace art
50 
51 #endif  // ART_COMPILER_OPTIMIZING_LINEAR_ORDER_H_
52