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 #include "dead_code_elimination.h" 18 19 #include "driver/compiler_options.h" 20 #include "graph_checker.h" 21 #include "optimizing_unit_test.h" 22 #include "pretty_printer.h" 23 24 #include "gtest/gtest.h" 25 26 namespace art { 27 28 class DeadCodeEliminationTest : public OptimizingUnitTest { 29 protected: 30 void TestCode(const std::vector<uint16_t>& data, 31 const std::string& expected_before, 32 const std::string& expected_after); 33 }; 34 35 void DeadCodeEliminationTest::TestCode(const std::vector<uint16_t>& data, 36 const std::string& expected_before, 37 const std::string& expected_after) { 38 HGraph* graph = CreateCFG(data); 39 ASSERT_NE(graph, nullptr); 40 41 StringPrettyPrinter printer_before(graph); 42 printer_before.VisitInsertionOrder(); 43 std::string actual_before = printer_before.str(); 44 ASSERT_EQ(actual_before, expected_before); 45 46 HDeadCodeElimination(graph, /* stats= */ nullptr, "dead_code_elimination").Run(); 47 GraphChecker graph_checker(graph); 48 graph_checker.Run(); 49 ASSERT_TRUE(graph_checker.IsValid()); 50 51 StringPrettyPrinter printer_after(graph); 52 printer_after.VisitInsertionOrder(); 53 std::string actual_after = printer_after.str(); 54 ASSERT_EQ(actual_after, expected_after); 55 } 56 57 /** 58 * Small three-register program. 59 * 60 * 16-bit 61 * offset 62 * ------ 63 * v1 <- 1 0. const/4 v1, #+1 64 * v0 <- 0 1. const/4 v0, #+0 65 * if v1 >= 0 goto L1 2. if-gez v1, +3 66 * v0 <- v1 4. move v0, v1 67 * L1: v2 <- v0 + v1 5. add-int v2, v0, v1 68 * return-void 7. return 69 */ 70 TEST_F(DeadCodeEliminationTest, AdditionAndConditionalJump) { 71 const std::vector<uint16_t> data = THREE_REGISTERS_CODE_ITEM( 72 Instruction::CONST_4 | 1 << 8 | 1 << 12, 73 Instruction::CONST_4 | 0 << 8 | 0 << 12, 74 Instruction::IF_GEZ | 1 << 8, 3, 75 Instruction::MOVE | 0 << 8 | 1 << 12, 76 Instruction::ADD_INT | 2 << 8, 0 | 1 << 8, 77 Instruction::RETURN_VOID); 78 79 std::string expected_before = 80 "BasicBlock 0, succ: 1\n" 81 " 3: IntConstant [9, 8, 5]\n" 82 " 4: IntConstant [8, 5]\n" 83 " 1: SuspendCheck\n" 84 " 2: Goto 1\n" 85 "BasicBlock 1, pred: 0, succ: 5, 2\n" 86 " 5: GreaterThanOrEqual(3, 4) [6]\n" 87 " 6: If(5)\n" 88 "BasicBlock 2, pred: 1, succ: 3\n" 89 " 7: Goto 3\n" 90 "BasicBlock 3, pred: 5, 2, succ: 4\n" 91 " 8: Phi(4, 3) [9]\n" 92 " 9: Add(8, 3)\n" 93 " 10: ReturnVoid\n" 94 "BasicBlock 4, pred: 3\n" 95 " 11: Exit\n" 96 "BasicBlock 5, pred: 1, succ: 3\n" 97 " 0: Goto 3\n"; 98 99 // Expected difference after dead code elimination. 100 diff_t expected_diff = { 101 { " 3: IntConstant [9, 8, 5]\n", " 3: IntConstant [8, 5]\n" }, 102 { " 8: Phi(4, 3) [9]\n", " 8: Phi(4, 3)\n" }, 103 { " 9: Add(8, 3)\n", removed } 104 }; 105 std::string expected_after = Patch(expected_before, expected_diff); 106 107 TestCode(data, expected_before, expected_after); 108 } 109 110 /** 111 * Three-register program with jumps leading to the creation of many 112 * blocks. 113 * 114 * The intent of this test is to ensure that all dead instructions are 115 * actually pruned at compile-time, thanks to the (backward) 116 * post-order traversal of the the dominator tree. 117 * 118 * 16-bit 119 * offset 120 * ------ 121 * v0 <- 0 0. const/4 v0, #+0 122 * v1 <- 1 1. const/4 v1, #+1 123 * v2 <- v0 + v1 2. add-int v2, v0, v1 124 * goto L2 4. goto +4 125 * L1: v1 <- v0 + 3 5. add-int/lit16 v1, v0, #+3 126 * goto L3 7. goto +4 127 * L2: v0 <- v2 + 2 8. add-int/lit16 v0, v2, #+2 128 * goto L1 10. goto +(-5) 129 * L3: v2 <- v1 + 4 11. add-int/lit16 v2, v1, #+4 130 * return 13. return-void 131 */ 132 TEST_F(DeadCodeEliminationTest, AdditionsAndInconditionalJumps) { 133 const std::vector<uint16_t> data = THREE_REGISTERS_CODE_ITEM( 134 Instruction::CONST_4 | 0 << 8 | 0 << 12, 135 Instruction::CONST_4 | 1 << 8 | 1 << 12, 136 Instruction::ADD_INT | 2 << 8, 0 | 1 << 8, 137 Instruction::GOTO | 4 << 8, 138 Instruction::ADD_INT_LIT16 | 1 << 8 | 0 << 12, 3, 139 Instruction::GOTO | 4 << 8, 140 Instruction::ADD_INT_LIT16 | 0 << 8 | 2 << 12, 2, 141 static_cast<uint16_t>(Instruction::GOTO | 0xFFFFFFFB << 8), 142 Instruction::ADD_INT_LIT16 | 2 << 8 | 1 << 12, 4, 143 Instruction::RETURN_VOID); 144 145 std::string expected_before = 146 "BasicBlock 0, succ: 1\n" 147 " 2: IntConstant [4]\n" 148 " 3: IntConstant [4]\n" 149 " 6: IntConstant [7]\n" 150 " 9: IntConstant [10]\n" 151 " 12: IntConstant [13]\n" 152 " 0: SuspendCheck\n" 153 " 1: Goto 1\n" 154 "BasicBlock 1, pred: 0, succ: 3\n" 155 " 4: Add(2, 3) [7]\n" 156 " 5: Goto 3\n" 157 "BasicBlock 2, pred: 3, succ: 4\n" 158 " 10: Add(7, 9) [13]\n" 159 " 11: Goto 4\n" 160 "BasicBlock 3, pred: 1, succ: 2\n" 161 " 7: Add(4, 6) [10]\n" 162 " 8: Goto 2\n" 163 "BasicBlock 4, pred: 2, succ: 5\n" 164 " 13: Add(10, 12)\n" 165 " 14: ReturnVoid\n" 166 "BasicBlock 5, pred: 4\n" 167 " 15: Exit\n"; 168 169 std::string expected_after = 170 "BasicBlock 0, succ: 1\n" 171 " 0: SuspendCheck\n" 172 " 1: Goto 1\n" 173 "BasicBlock 1, pred: 0, succ: 5\n" 174 " 14: ReturnVoid\n" 175 "BasicBlock 5, pred: 1\n" 176 " 15: Exit\n"; 177 178 TestCode(data, expected_before, expected_after); 179 } 180 181 } // namespace art 182
