Linearize the graph before creating live ranges.

Change-Id: I02eb5671e3304ab062286131745c1366448aff58
diff --git a/compiler/optimizing/linearize_test.cc b/compiler/optimizing/linearize_test.cc
new file mode 100644
index 0000000..4c819a2
--- /dev/null
+++ b/compiler/optimizing/linearize_test.cc
@@ -0,0 +1,190 @@
+/*
+ * Copyright (C) 2014 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.
+ */
+
+#include <fstream>
+
+#include "base/stringprintf.h"
+#include "builder.h"
+#include "dex_file.h"
+#include "dex_instruction.h"
+#include "graph_visualizer.h"
+#include "nodes.h"
+#include "optimizing_unit_test.h"
+#include "pretty_printer.h"
+#include "ssa_builder.h"
+#include "ssa_liveness_analysis.h"
+#include "utils/arena_allocator.h"
+
+#include "gtest/gtest.h"
+
+namespace art {
+
+static void TestCode(const uint16_t* data, const int* expected_order, size_t number_of_blocks) {
+  ArenaPool pool;
+  ArenaAllocator allocator(&pool);
+  HGraphBuilder builder(&allocator);
+  const DexFile::CodeItem* item = reinterpret_cast<const DexFile::CodeItem*>(data);
+  HGraph* graph = builder.BuildGraph(*item);
+  ASSERT_NE(graph, nullptr);
+
+  graph->BuildDominatorTree();
+  graph->FindNaturalLoops();
+  SsaLivenessAnalysis liveness(*graph);
+  liveness.Analyze();
+
+  ASSERT_EQ(liveness.GetLinearPostOrder().Size(), number_of_blocks);
+  for (size_t i = 0; i < number_of_blocks; ++i) {
+    ASSERT_EQ(liveness.GetLinearPostOrder().Get(number_of_blocks - i - 1)->GetBlockId(),
+              expected_order[i]);
+  }
+}
+
+TEST(LinearizeTest, CFG1) {
+  // Structure of this graph (* are back edges)
+  //            Block0
+  //              |
+  //            Block1
+  //              |
+  //            Block2 ******
+  //            /   \       *
+  //       Block5   Block7  *
+  //         |        |     *
+  //       Block6   Block3  *
+  //               * /   \  *
+  //           Block4   Block8
+
+  const uint16_t data[] = ONE_REGISTER_CODE_ITEM(
+    Instruction::CONST_4 | 0 | 0,
+    Instruction::IF_EQ, 5,
+    Instruction::IF_EQ, 0xFFFE,
+    Instruction::GOTO | 0xFE00,
+    Instruction::RETURN_VOID);
+
+  const int blocks[] = {0, 1, 2, 7, 3, 4, 8, 5, 6};
+  TestCode(data, blocks, 9);
+}
+
+TEST(LinearizeTest, CFG2) {
+  // Structure of this graph (* are back edges)
+  //            Block0
+  //              |
+  //            Block1
+  //              |
+  //            Block2 ******
+  //            /   \       *
+  //       Block3   Block7  *
+  //         |        |     *
+  //       Block6   Block4  *
+  //               * /   \  *
+  //           Block5   Block8
+
+  const uint16_t data[] = ONE_REGISTER_CODE_ITEM(
+    Instruction::CONST_4 | 0 | 0,
+    Instruction::IF_EQ, 3,
+    Instruction::RETURN_VOID,
+    Instruction::IF_EQ, 0xFFFD,
+    Instruction::GOTO | 0xFE00);
+
+  const int blocks[] = {0, 1, 2, 7, 4, 5, 8, 3, 6};
+  TestCode(data, blocks, 9);
+}
+
+TEST(LinearizeTest, CFG3) {
+  // Structure of this graph (* are back edges)
+  //            Block0
+  //              |
+  //            Block1
+  //              |
+  //            Block2 ******
+  //            /   \       *
+  //       Block3   Block8  *
+  //         |        |     *
+  //       Block7   Block5  *
+  //                 / *  \ *
+  //           Block6  * Block9
+  //             |     *
+  //           Block4 **
+  const uint16_t data[] = ONE_REGISTER_CODE_ITEM(
+    Instruction::CONST_4 | 0 | 0,
+    Instruction::IF_EQ, 4,
+    Instruction::RETURN_VOID,
+    Instruction::GOTO | 0x0100,
+    Instruction::IF_EQ, 0xFFFC,
+    Instruction::GOTO | 0xFD00);
+
+  const int blocks[] = {0, 1, 2, 8, 5, 6, 4, 9, 3, 7};
+  TestCode(data, blocks, 10);
+}
+
+TEST(LinearizeTest, CFG4) {
+  // Structure of this graph (* are back edges)
+  //            Block0
+  //              |
+  //            Block1
+  //              |
+  //            Block2
+  //            / *  \
+  //       Block6 * Block8
+  //         |    *   |
+  //       Block7 * Block3 *******
+  //              *  /  \        *
+  //           Block9   Block10  *
+  //                      |      *
+  //                    Block4   *
+  //                   */    \   *
+  //                Block5  Block11
+  const uint16_t data[] = ONE_REGISTER_CODE_ITEM(
+    Instruction::CONST_4 | 0 | 0,
+    Instruction::IF_EQ, 7,
+    Instruction::IF_EQ, 0xFFFE,
+    Instruction::IF_EQ, 0xFFFE,
+    Instruction::GOTO | 0xFE00,
+    Instruction::RETURN_VOID);
+
+  const int blocks[] = {0, 1, 2, 8, 3, 10, 4, 5, 11, 9, 6, 7};
+  TestCode(data, blocks, 12);
+}
+
+TEST(LinearizeTest, CFG5) {
+  // Structure of this graph (* are back edges)
+  //            Block0
+  //              |
+  //            Block1
+  //              |
+  //            Block2
+  //            / *  \
+  //       Block3 * Block8
+  //         |    *   |
+  //       Block7 * Block4 *******
+  //              *  /  \        *
+  //           Block9   Block10  *
+  //                      |      *
+  //                    Block5   *
+  //                   */    \   *
+  //                Block6  Block11
+  const uint16_t data[] = ONE_REGISTER_CODE_ITEM(
+    Instruction::CONST_4 | 0 | 0,
+    Instruction::IF_EQ, 3,
+    Instruction::RETURN_VOID,
+    Instruction::IF_EQ, 0xFFFD,
+    Instruction::IF_EQ, 0xFFFE,
+    Instruction::GOTO | 0xFE00);
+
+  const int blocks[] = {0, 1, 2, 8, 4, 10, 5, 6, 11, 9, 3, 7};
+  TestCode(data, blocks, 12);
+}
+
+}  // namespace art