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diff --git a/compiler/optimizing/block_builder.h b/compiler/optimizing/block_builder.h
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+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_COMPILER_OPTIMIZING_BLOCK_BUILDER_H_
+#define ART_COMPILER_OPTIMIZING_BLOCK_BUILDER_H_
+
+#include "base/arena_containers.h"
+#include "base/arena_object.h"
+#include "dex_file.h"
+#include "nodes.h"
+
+namespace art {
+
+class HBasicBlockBuilder : public ValueObject {
+ public:
+  HBasicBlockBuilder(HGraph* graph,
+                     const DexFile* const dex_file,
+                     const DexFile::CodeItem& code_item)
+      : arena_(graph->GetArena()),
+        graph_(graph),
+        dex_file_(dex_file),
+        code_item_(code_item),
+        branch_targets_(code_item.insns_size_in_code_units_,
+                        nullptr,
+                        arena_->Adapter(kArenaAllocGraphBuilder)),
+        throwing_blocks_(kDefaultNumberOfThrowingBlocks, arena_->Adapter(kArenaAllocGraphBuilder)),
+        number_of_branches_(0u) {}
+
+  // Creates basic blocks in `graph_` at branch target dex_pc positions of the
+  // `code_item_`. Blocks are connected but left unpopulated with instructions.
+  // TryBoundary blocks are inserted at positions where control-flow enters/
+  // exits a try block.
+  bool Build();
+
+  size_t GetNumberOfBranches() const { return number_of_branches_; }
+  HBasicBlock* GetBlockAt(uint32_t dex_pc) const { return branch_targets_[dex_pc]; }
+
+ private:
+  // Creates a basic block starting at given `dex_pc`.
+  HBasicBlock* MaybeCreateBlockAt(uint32_t dex_pc);
+
+  // Creates a basic block for bytecode instructions at `semantic_dex_pc` and
+  // stores it under the `store_dex_pc` key. This is used when multiple blocks
+  // share the same semantic dex_pc, e.g. when building switch decision trees.
+  HBasicBlock* MaybeCreateBlockAt(uint32_t semantic_dex_pc, uint32_t store_dex_pc);
+
+  bool CreateBranchTargets();
+  void ConnectBasicBlocks();
+  void InsertTryBoundaryBlocks();
+
+  // Helper method which decides whether `catch_block` may have live normal
+  // predecessors and thus whether a synthetic catch block needs to be created
+  // to avoid mixing normal and exceptional predecessors.
+  // Should only be called during InsertTryBoundaryBlocks on blocks at catch
+  // handler dex_pcs.
+  bool MightHaveLiveNormalPredecessors(HBasicBlock* catch_block);
+
+  ArenaAllocator* const arena_;
+  HGraph* const graph_;
+
+  const DexFile* const dex_file_;
+  const DexFile::CodeItem& code_item_;
+
+  ArenaVector<HBasicBlock*> branch_targets_;
+  ArenaVector<HBasicBlock*> throwing_blocks_;
+  size_t number_of_branches_;
+
+  static constexpr size_t kDefaultNumberOfThrowingBlocks = 2u;
+
+  DISALLOW_COPY_AND_ASSIGN(HBasicBlockBuilder);
+};
+
+}  // namespace art
+
+#endif  // ART_COMPILER_OPTIMIZING_BLOCK_BUILDER_H_