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 "arch/x86/instruction_set_features_x86.h" 18#include "code_generator_x86.h" 19#include "dead_code_elimination.h" 20#include "driver/compiler_options.h" 21#include "graph_checker.h" 22#include "optimizing_unit_test.h" 23#include "pretty_printer.h" 24 25#include "gtest/gtest.h" 26 27namespace art { 28 29class DeadCodeEliminationTest : public CommonCompilerTest {}; 30 31static void TestCode(const uint16_t* data, 32 const std::string& expected_before, 33 const std::string& expected_after) { 34 ArenaPool pool; 35 ArenaAllocator allocator(&pool); 36 HGraph* graph = CreateCFG(&allocator, data); 37 ASSERT_NE(graph, nullptr); 38 39 StringPrettyPrinter printer_before(graph); 40 printer_before.VisitInsertionOrder(); 41 std::string actual_before = printer_before.str(); 42 ASSERT_EQ(actual_before, expected_before); 43 44 std::unique_ptr<const X86InstructionSetFeatures> features_x86( 45 X86InstructionSetFeatures::FromCppDefines()); 46 x86::CodeGeneratorX86 codegenX86(graph, *features_x86.get(), CompilerOptions()); 47 HDeadCodeElimination(graph).Run(); 48 GraphChecker graph_checker(graph); 49 graph_checker.Run(); 50 ASSERT_TRUE(graph_checker.IsValid()); 51 52 StringPrettyPrinter printer_after(graph); 53 printer_after.VisitInsertionOrder(); 54 std::string actual_after = printer_after.str(); 55 ASSERT_EQ(actual_after, expected_after); 56} 57 58/** 59 * Small three-register program. 60 * 61 * 16-bit 62 * offset 63 * ------ 64 * v1 <- 1 0. const/4 v1, #+1 65 * v0 <- 0 1. const/4 v0, #+0 66 * if v1 >= 0 goto L1 2. if-gez v1, +3 67 * v0 <- v1 4. move v0, v1 68 * L1: v2 <- v0 + v1 5. add-int v2, v0, v1 69 * return-void 7. return 70 */ 71TEST_F(DeadCodeEliminationTest, AdditionAndConditionalJump) { 72 const uint16_t data[] = THREE_REGISTERS_CODE_ITEM( 73 Instruction::CONST_4 | 1 << 8 | 1 << 12, 74 Instruction::CONST_4 | 0 << 8 | 0 << 12, 75 Instruction::IF_GEZ | 1 << 8, 3, 76 Instruction::MOVE | 0 << 8 | 1 << 12, 77 Instruction::ADD_INT | 2 << 8, 0 | 1 << 8, 78 Instruction::RETURN_VOID); 79 80 std::string expected_before = 81 "BasicBlock 0, succ: 1\n" 82 " 3: IntConstant [9, 8, 5]\n" 83 " 4: IntConstant [8, 5]\n" 84 " 1: SuspendCheck\n" 85 " 2: Goto 1\n" 86 "BasicBlock 1, pred: 0, succ: 5, 2\n" 87 " 5: GreaterThanOrEqual(3, 4) [6]\n" 88 " 6: If(5)\n" 89 "BasicBlock 2, pred: 1, succ: 3\n" 90 " 7: Goto 3\n" 91 "BasicBlock 3, pred: 5, 2, succ: 4\n" 92 " 8: Phi(4, 3) [9]\n" 93 " 9: Add(8, 3)\n" 94 " 10: ReturnVoid\n" 95 "BasicBlock 4, pred: 3\n" 96 " 11: Exit\n" 97 "BasicBlock 5, pred: 1, succ: 3\n" 98 " 0: Goto 3\n"; 99 100 // Expected difference after dead code elimination. 101 diff_t expected_diff = { 102 { " 3: IntConstant [9, 8, 5]\n", " 3: IntConstant [8, 5]\n" }, 103 { " 8: Phi(4, 3) [9]\n", " 8: Phi(4, 3)\n" }, 104 { " 9: Add(8, 3)\n", removed } 105 }; 106 std::string expected_after = Patch(expected_before, expected_diff); 107 108 TestCode(data, expected_before, expected_after); 109} 110 111/** 112 * Three-register program with jumps leading to the creation of many 113 * blocks. 114 * 115 * The intent of this test is to ensure that all dead instructions are 116 * actually pruned at compile-time, thanks to the (backward) 117 * post-order traversal of the the dominator tree. 118 * 119 * 16-bit 120 * offset 121 * ------ 122 * v0 <- 0 0. const/4 v0, #+0 123 * v1 <- 1 1. const/4 v1, #+1 124 * v2 <- v0 + v1 2. add-int v2, v0, v1 125 * goto L2 4. goto +4 126 * L1: v1 <- v0 + 3 5. add-int/lit16 v1, v0, #+3 127 * goto L3 7. goto +4 128 * L2: v0 <- v2 + 2 8. add-int/lit16 v0, v2, #+2 129 * goto L1 10. goto +(-5) 130 * L3: v2 <- v1 + 4 11. add-int/lit16 v2, v1, #+4 131 * return 13. return-void 132 */ 133TEST_F(DeadCodeEliminationTest, AdditionsAndInconditionalJumps) { 134 const uint16_t data[] = THREE_REGISTERS_CODE_ITEM( 135 Instruction::CONST_4 | 0 << 8 | 0 << 12, 136 Instruction::CONST_4 | 1 << 8 | 1 << 12, 137 Instruction::ADD_INT | 2 << 8, 0 | 1 << 8, 138 Instruction::GOTO | 4 << 8, 139 Instruction::ADD_INT_LIT16 | 1 << 8 | 0 << 12, 3, 140 Instruction::GOTO | 4 << 8, 141 Instruction::ADD_INT_LIT16 | 0 << 8 | 2 << 12, 2, 142 static_cast<uint16_t>(Instruction::GOTO | 0xFFFFFFFB << 8), 143 Instruction::ADD_INT_LIT16 | 2 << 8 | 1 << 12, 4, 144 Instruction::RETURN_VOID); 145 146 std::string expected_before = 147 "BasicBlock 0, succ: 1\n" 148 " 2: IntConstant [4]\n" 149 " 3: IntConstant [4]\n" 150 " 6: IntConstant [7]\n" 151 " 9: IntConstant [10]\n" 152 " 12: IntConstant [13]\n" 153 " 0: SuspendCheck\n" 154 " 1: Goto 1\n" 155 "BasicBlock 1, pred: 0, succ: 3\n" 156 " 4: Add(2, 3) [7]\n" 157 " 5: Goto 3\n" 158 "BasicBlock 2, pred: 3, succ: 4\n" 159 " 10: Add(7, 9) [13]\n" 160 " 11: Goto 4\n" 161 "BasicBlock 3, pred: 1, succ: 2\n" 162 " 7: Add(4, 6) [10]\n" 163 " 8: Goto 2\n" 164 "BasicBlock 4, pred: 2, succ: 5\n" 165 " 13: Add(10, 12)\n" 166 " 14: ReturnVoid\n" 167 "BasicBlock 5, pred: 4\n" 168 " 15: Exit\n"; 169 170 std::string expected_after = 171 "BasicBlock 0, succ: 1\n" 172 " 0: SuspendCheck\n" 173 " 1: Goto 1\n" 174 "BasicBlock 1, pred: 0, succ: 5\n" 175 " 14: ReturnVoid\n" 176 "BasicBlock 5, pred: 1\n" 177 " 15: Exit\n"; 178 179 TestCode(data, expected_before, expected_after); 180} 181 182} // namespace art 183