| /* | 
 |  * 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 <functional> | 
 |  | 
 | #include "constant_folding.h" | 
 | #include "dead_code_elimination.h" | 
 | #include "driver/compiler_options.h" | 
 | #include "graph_checker.h" | 
 | #include "optimizing_unit_test.h" | 
 | #include "pretty_printer.h" | 
 |  | 
 | #include "gtest/gtest.h" | 
 |  | 
 | namespace art { | 
 |  | 
 | /** | 
 |  * Fixture class for the constant folding and dce tests. | 
 |  */ | 
 | class ConstantFoldingTest : public OptimizingUnitTest { | 
 |  public: | 
 |   ConstantFoldingTest() : graph_(nullptr) { } | 
 |  | 
 |   void TestCode(const std::vector<uint16_t>& data, | 
 |                 const std::string& expected_before, | 
 |                 const std::string& expected_after_cf, | 
 |                 const std::string& expected_after_dce, | 
 |                 const std::function<void(HGraph*)>& check_after_cf, | 
 |                 DataType::Type return_type = DataType::Type::kInt32) { | 
 |     graph_ = CreateCFG(data, return_type); | 
 |     TestCodeOnReadyGraph(expected_before, | 
 |                          expected_after_cf, | 
 |                          expected_after_dce, | 
 |                          check_after_cf); | 
 |   } | 
 |  | 
 |   void TestCodeOnReadyGraph(const std::string& expected_before, | 
 |                             const std::string& expected_after_cf, | 
 |                             const std::string& expected_after_dce, | 
 |                             const std::function<void(HGraph*)>& check_after_cf) { | 
 |     ASSERT_NE(graph_, nullptr); | 
 |  | 
 |     StringPrettyPrinter printer_before(graph_); | 
 |     printer_before.VisitInsertionOrder(); | 
 |     std::string actual_before = printer_before.str(); | 
 |     EXPECT_EQ(expected_before, actual_before); | 
 |  | 
 |     HConstantFolding(graph_, "constant_folding").Run(); | 
 |     GraphChecker graph_checker_cf(graph_); | 
 |     graph_checker_cf.Run(); | 
 |     ASSERT_TRUE(graph_checker_cf.IsValid()); | 
 |  | 
 |     StringPrettyPrinter printer_after_cf(graph_); | 
 |     printer_after_cf.VisitInsertionOrder(); | 
 |     std::string actual_after_cf = printer_after_cf.str(); | 
 |     EXPECT_EQ(expected_after_cf, actual_after_cf); | 
 |  | 
 |     check_after_cf(graph_); | 
 |  | 
 |     HDeadCodeElimination(graph_, nullptr /* stats */, "dead_code_elimination").Run(); | 
 |     GraphChecker graph_checker_dce(graph_); | 
 |     graph_checker_dce.Run(); | 
 |     ASSERT_TRUE(graph_checker_dce.IsValid()); | 
 |  | 
 |     StringPrettyPrinter printer_after_dce(graph_); | 
 |     printer_after_dce.VisitInsertionOrder(); | 
 |     std::string actual_after_dce = printer_after_dce.str(); | 
 |     EXPECT_EQ(expected_after_dce, actual_after_dce); | 
 |   } | 
 |  | 
 |   HGraph* graph_; | 
 | }; | 
 |  | 
 | /** | 
 |  * Tiny three-register program exercising int constant folding on negation. | 
 |  * | 
 |  *                              16-bit | 
 |  *                              offset | 
 |  *                              ------ | 
 |  *     v0 <- 1                  0.      const/4 v0, #+1 | 
 |  *     v1 <- -v0                1.      neg-int v1, v0 | 
 |  *     return v1                2.      return v1 | 
 |  */ | 
 | TEST_F(ConstantFoldingTest, IntConstantFoldingNegation) { | 
 |   const std::vector<uint16_t> data = TWO_REGISTERS_CODE_ITEM( | 
 |     Instruction::CONST_4 | 0 << 8 | 1 << 12, | 
 |     Instruction::NEG_INT | 1 << 8 | 0 << 12, | 
 |     Instruction::RETURN | 1 << 8); | 
 |  | 
 |   std::string expected_before = | 
 |       "BasicBlock 0, succ: 1\n" | 
 |       "  2: IntConstant [3]\n" | 
 |       "  0: SuspendCheck\n" | 
 |       "  1: Goto 1\n" | 
 |       "BasicBlock 1, pred: 0, succ: 2\n" | 
 |       "  3: Neg(2) [4]\n" | 
 |       "  4: Return(3)\n" | 
 |       "BasicBlock 2, pred: 1\n" | 
 |       "  5: Exit\n"; | 
 |  | 
 |   // Expected difference after constant folding. | 
 |   diff_t expected_cf_diff = { | 
 |     { "  2: IntConstant [3]\n", "  2: IntConstant\n" | 
 |                                 "  6: IntConstant [4]\n" }, | 
 |     { "  3: Neg(2) [4]\n",      removed }, | 
 |     { "  4: Return(3)\n",       "  4: Return(6)\n" } | 
 |   }; | 
 |   std::string expected_after_cf = Patch(expected_before, expected_cf_diff); | 
 |  | 
 |   // Check the value of the computed constant. | 
 |   auto check_after_cf = [](HGraph* graph) { | 
 |     HInstruction* inst = graph->GetBlocks()[1]->GetFirstInstruction()->InputAt(0); | 
 |     ASSERT_TRUE(inst->IsIntConstant()); | 
 |     ASSERT_EQ(inst->AsIntConstant()->GetValue(), -1); | 
 |   }; | 
 |  | 
 |   // Expected difference after dead code elimination. | 
 |   diff_t expected_dce_diff = { | 
 |     { "  2: IntConstant\n", removed }, | 
 |   }; | 
 |   std::string expected_after_dce = Patch(expected_after_cf, expected_dce_diff); | 
 |  | 
 |   TestCode(data, | 
 |            expected_before, | 
 |            expected_after_cf, | 
 |            expected_after_dce, | 
 |            check_after_cf); | 
 | } | 
 |  | 
 | /** | 
 |  * Tiny three-register program exercising long constant folding on negation. | 
 |  * | 
 |  *                              16-bit | 
 |  *                              offset | 
 |  *                              ------ | 
 |  *     (v0, v1) <- 4294967296   0.      const-wide v0 #+4294967296 | 
 |  *     (v2, v3) <- -(v0, v1)    1.      neg-long v2, v0 | 
 |  *     return (v2, v3)          2.      return-wide v2 | 
 |  */ | 
 | TEST_F(ConstantFoldingTest, LongConstantFoldingNegation) { | 
 |   const int64_t input = INT64_C(4294967296);             // 2^32 | 
 |   const uint16_t word0 = Low16Bits(Low32Bits(input));    // LSW. | 
 |   const uint16_t word1 = High16Bits(Low32Bits(input)); | 
 |   const uint16_t word2 = Low16Bits(High32Bits(input)); | 
 |   const uint16_t word3 = High16Bits(High32Bits(input));  // MSW. | 
 |   const std::vector<uint16_t> data = FOUR_REGISTERS_CODE_ITEM( | 
 |     Instruction::CONST_WIDE | 0 << 8, word0, word1, word2, word3, | 
 |     Instruction::NEG_LONG | 2 << 8 | 0 << 12, | 
 |     Instruction::RETURN_WIDE | 2 << 8); | 
 |  | 
 |   std::string expected_before = | 
 |       "BasicBlock 0, succ: 1\n" | 
 |       "  2: LongConstant [3]\n" | 
 |       "  0: SuspendCheck\n" | 
 |       "  1: Goto 1\n" | 
 |       "BasicBlock 1, pred: 0, succ: 2\n" | 
 |       "  3: Neg(2) [4]\n" | 
 |       "  4: Return(3)\n" | 
 |       "BasicBlock 2, pred: 1\n" | 
 |       "  5: Exit\n"; | 
 |  | 
 |   // Expected difference after constant folding. | 
 |   diff_t expected_cf_diff = { | 
 |     { "  2: LongConstant [3]\n", "  2: LongConstant\n" | 
 |                                  "  6: LongConstant [4]\n" }, | 
 |     { "  3: Neg(2) [4]\n",       removed }, | 
 |     { "  4: Return(3)\n",        "  4: Return(6)\n" } | 
 |   }; | 
 |   std::string expected_after_cf = Patch(expected_before, expected_cf_diff); | 
 |  | 
 |   // Check the value of the computed constant. | 
 |   auto check_after_cf = [](HGraph* graph) { | 
 |     HInstruction* inst = graph->GetBlocks()[1]->GetFirstInstruction()->InputAt(0); | 
 |     ASSERT_TRUE(inst->IsLongConstant()); | 
 |     ASSERT_EQ(inst->AsLongConstant()->GetValue(), INT64_C(-4294967296)); | 
 |   }; | 
 |  | 
 |   // Expected difference after dead code elimination. | 
 |   diff_t expected_dce_diff = { | 
 |     { "  2: LongConstant\n", removed }, | 
 |   }; | 
 |   std::string expected_after_dce = Patch(expected_after_cf, expected_dce_diff); | 
 |  | 
 |   TestCode(data, | 
 |            expected_before, | 
 |            expected_after_cf, | 
 |            expected_after_dce, | 
 |            check_after_cf, | 
 |            DataType::Type::kInt64); | 
 | } | 
 |  | 
 | /** | 
 |  * Tiny three-register program exercising int constant folding on addition. | 
 |  * | 
 |  *                              16-bit | 
 |  *                              offset | 
 |  *                              ------ | 
 |  *     v0 <- 1                  0.      const/4 v0, #+1 | 
 |  *     v1 <- 2                  1.      const/4 v1, #+2 | 
 |  *     v2 <- v0 + v1            2.      add-int v2, v0, v1 | 
 |  *     return v2                4.      return v2 | 
 |  */ | 
 | TEST_F(ConstantFoldingTest, IntConstantFoldingOnAddition1) { | 
 |   const std::vector<uint16_t> data = THREE_REGISTERS_CODE_ITEM( | 
 |     Instruction::CONST_4 | 0 << 8 | 1 << 12, | 
 |     Instruction::CONST_4 | 1 << 8 | 2 << 12, | 
 |     Instruction::ADD_INT | 2 << 8, 0 | 1 << 8, | 
 |     Instruction::RETURN | 2 << 8); | 
 |  | 
 |   std::string expected_before = | 
 |       "BasicBlock 0, succ: 1\n" | 
 |       "  2: IntConstant [4]\n" | 
 |       "  3: IntConstant [4]\n" | 
 |       "  0: SuspendCheck\n" | 
 |       "  1: Goto 1\n" | 
 |       "BasicBlock 1, pred: 0, succ: 2\n" | 
 |       "  4: Add(2, 3) [5]\n" | 
 |       "  5: Return(4)\n" | 
 |       "BasicBlock 2, pred: 1\n" | 
 |       "  6: Exit\n"; | 
 |  | 
 |   // Expected difference after constant folding. | 
 |   diff_t expected_cf_diff = { | 
 |     { "  2: IntConstant [4]\n", "  2: IntConstant\n" }, | 
 |     { "  3: IntConstant [4]\n", "  3: IntConstant\n" | 
 |                                 "  7: IntConstant [5]\n" }, | 
 |     { "  4: Add(2, 3) [5]\n",   removed }, | 
 |     { "  5: Return(4)\n",       "  5: Return(7)\n" } | 
 |   }; | 
 |   std::string expected_after_cf = Patch(expected_before, expected_cf_diff); | 
 |  | 
 |   // Check the value of the computed constant. | 
 |   auto check_after_cf = [](HGraph* graph) { | 
 |     HInstruction* inst = graph->GetBlocks()[1]->GetFirstInstruction()->InputAt(0); | 
 |     ASSERT_TRUE(inst->IsIntConstant()); | 
 |     ASSERT_EQ(inst->AsIntConstant()->GetValue(), 3); | 
 |   }; | 
 |  | 
 |   // Expected difference after dead code elimination. | 
 |   diff_t expected_dce_diff = { | 
 |     { "  2: IntConstant\n", removed }, | 
 |     { "  3: IntConstant\n", removed } | 
 |   }; | 
 |   std::string expected_after_dce = Patch(expected_after_cf, expected_dce_diff); | 
 |  | 
 |   TestCode(data, | 
 |            expected_before, | 
 |            expected_after_cf, | 
 |            expected_after_dce, | 
 |            check_after_cf); | 
 | } | 
 |  | 
 | /** | 
 |  * Small three-register program exercising int constant folding on addition. | 
 |  * | 
 |  *                              16-bit | 
 |  *                              offset | 
 |  *                              ------ | 
 |  *     v0 <- 1                  0.      const/4 v0, #+1 | 
 |  *     v1 <- 2                  1.      const/4 v1, #+2 | 
 |  *     v0 <- v0 + v1            2.      add-int/2addr v0, v1 | 
 |  *     v1 <- 4                  3.      const/4 v1, #+4 | 
 |  *     v2 <- 5                  4.      const/4 v2, #+5 | 
 |  *     v1 <- v1 + v2            5.      add-int/2addr v1, v2 | 
 |  *     v2 <- v0 + v1            6.      add-int v2, v0, v1 | 
 |  *     return v2                8.      return v2 | 
 |  */ | 
 | TEST_F(ConstantFoldingTest, IntConstantFoldingOnAddition2) { | 
 |   const std::vector<uint16_t> data = THREE_REGISTERS_CODE_ITEM( | 
 |     Instruction::CONST_4 | 0 << 8 | 1 << 12, | 
 |     Instruction::CONST_4 | 1 << 8 | 2 << 12, | 
 |     Instruction::ADD_INT_2ADDR | 0 << 8 | 1 << 12, | 
 |     Instruction::CONST_4 | 1 << 8 | 4 << 12, | 
 |     Instruction::CONST_4 | 2 << 8 | 5 << 12, | 
 |     Instruction::ADD_INT_2ADDR | 1 << 8 | 2 << 12, | 
 |     Instruction::ADD_INT | 2 << 8, 0 | 1 << 8, | 
 |     Instruction::RETURN | 2 << 8); | 
 |  | 
 |   std::string expected_before = | 
 |       "BasicBlock 0, succ: 1\n" | 
 |       "  2: IntConstant [4]\n" | 
 |       "  3: IntConstant [4]\n" | 
 |       "  5: IntConstant [7]\n" | 
 |       "  6: IntConstant [7]\n" | 
 |       "  0: SuspendCheck\n" | 
 |       "  1: Goto 1\n" | 
 |       "BasicBlock 1, pred: 0, succ: 2\n" | 
 |       "  4: Add(2, 3) [8]\n" | 
 |       "  7: Add(5, 6) [8]\n" | 
 |       "  8: Add(4, 7) [9]\n" | 
 |       "  9: Return(8)\n" | 
 |       "BasicBlock 2, pred: 1\n" | 
 |       "  10: Exit\n"; | 
 |  | 
 |   // Expected difference after constant folding. | 
 |   diff_t expected_cf_diff = { | 
 |     { "  2: IntConstant [4]\n",  "  2: IntConstant\n" }, | 
 |     { "  3: IntConstant [4]\n",  "  3: IntConstant\n" }, | 
 |     { "  5: IntConstant [7]\n",  "  5: IntConstant\n" }, | 
 |     { "  6: IntConstant [7]\n",  "  6: IntConstant\n" | 
 |                                  "  11: IntConstant\n" | 
 |                                  "  12: IntConstant\n" | 
 |                                  "  13: IntConstant [9]\n" }, | 
 |     { "  4: Add(2, 3) [8]\n",    removed }, | 
 |     { "  7: Add(5, 6) [8]\n",    removed }, | 
 |     { "  8: Add(4, 7) [9]\n",    removed  }, | 
 |     { "  9: Return(8)\n",        "  9: Return(13)\n" } | 
 |   }; | 
 |   std::string expected_after_cf = Patch(expected_before, expected_cf_diff); | 
 |  | 
 |   // Check the values of the computed constants. | 
 |   auto check_after_cf = [](HGraph* graph) { | 
 |     HInstruction* inst1 = graph->GetBlocks()[1]->GetFirstInstruction()->InputAt(0); | 
 |     ASSERT_TRUE(inst1->IsIntConstant()); | 
 |     ASSERT_EQ(inst1->AsIntConstant()->GetValue(), 12); | 
 |     HInstruction* inst2 = inst1->GetPrevious(); | 
 |     ASSERT_TRUE(inst2->IsIntConstant()); | 
 |     ASSERT_EQ(inst2->AsIntConstant()->GetValue(), 9); | 
 |     HInstruction* inst3 = inst2->GetPrevious(); | 
 |     ASSERT_TRUE(inst3->IsIntConstant()); | 
 |     ASSERT_EQ(inst3->AsIntConstant()->GetValue(), 3); | 
 |   }; | 
 |  | 
 |   // Expected difference after dead code elimination. | 
 |   diff_t expected_dce_diff = { | 
 |     { "  2: IntConstant\n",  removed }, | 
 |     { "  3: IntConstant\n",  removed }, | 
 |     { "  5: IntConstant\n",  removed }, | 
 |     { "  6: IntConstant\n",  removed }, | 
 |     { "  11: IntConstant\n", removed }, | 
 |     { "  12: IntConstant\n", removed } | 
 |   }; | 
 |   std::string expected_after_dce = Patch(expected_after_cf, expected_dce_diff); | 
 |  | 
 |   TestCode(data, | 
 |            expected_before, | 
 |            expected_after_cf, | 
 |            expected_after_dce, | 
 |            check_after_cf); | 
 | } | 
 |  | 
 | /** | 
 |  * Tiny three-register program exercising int constant folding on subtraction. | 
 |  * | 
 |  *                              16-bit | 
 |  *                              offset | 
 |  *                              ------ | 
 |  *     v0 <- 3                  0.      const/4 v0, #+3 | 
 |  *     v1 <- 2                  1.      const/4 v1, #+2 | 
 |  *     v2 <- v0 - v1            2.      sub-int v2, v0, v1 | 
 |  *     return v2                4.      return v2 | 
 |  */ | 
 | TEST_F(ConstantFoldingTest, IntConstantFoldingOnSubtraction) { | 
 |   const std::vector<uint16_t> data = THREE_REGISTERS_CODE_ITEM( | 
 |     Instruction::CONST_4 | 0 << 8 | 3 << 12, | 
 |     Instruction::CONST_4 | 1 << 8 | 2 << 12, | 
 |     Instruction::SUB_INT | 2 << 8, 0 | 1 << 8, | 
 |     Instruction::RETURN | 2 << 8); | 
 |  | 
 |   std::string expected_before = | 
 |       "BasicBlock 0, succ: 1\n" | 
 |       "  2: IntConstant [4]\n" | 
 |       "  3: IntConstant [4]\n" | 
 |       "  0: SuspendCheck\n" | 
 |       "  1: Goto 1\n" | 
 |       "BasicBlock 1, pred: 0, succ: 2\n" | 
 |       "  4: Sub(2, 3) [5]\n" | 
 |       "  5: Return(4)\n" | 
 |       "BasicBlock 2, pred: 1\n" | 
 |       "  6: Exit\n"; | 
 |  | 
 |   // Expected difference after constant folding. | 
 |   diff_t expected_cf_diff = { | 
 |     { "  2: IntConstant [4]\n",  "  2: IntConstant\n" }, | 
 |     { "  3: IntConstant [4]\n",  "  3: IntConstant\n" | 
 |                                  "  7: IntConstant [5]\n" }, | 
 |     { "  4: Sub(2, 3) [5]\n",    removed }, | 
 |     { "  5: Return(4)\n",        "  5: Return(7)\n" } | 
 |   }; | 
 |   std::string expected_after_cf = Patch(expected_before, expected_cf_diff); | 
 |  | 
 |   // Check the value of the computed constant. | 
 |   auto check_after_cf = [](HGraph* graph) { | 
 |     HInstruction* inst = graph->GetBlocks()[1]->GetFirstInstruction()->InputAt(0); | 
 |     ASSERT_TRUE(inst->IsIntConstant()); | 
 |     ASSERT_EQ(inst->AsIntConstant()->GetValue(), 1); | 
 |   }; | 
 |  | 
 |   // Expected difference after dead code elimination. | 
 |   diff_t expected_dce_diff = { | 
 |     { "  2: IntConstant\n", removed }, | 
 |     { "  3: IntConstant\n", removed } | 
 |   }; | 
 |   std::string expected_after_dce = Patch(expected_after_cf, expected_dce_diff); | 
 |  | 
 |   TestCode(data, | 
 |            expected_before, | 
 |            expected_after_cf, | 
 |            expected_after_dce, | 
 |            check_after_cf); | 
 | } | 
 |  | 
 | /** | 
 |  * Tiny three-register-pair program exercising long constant folding | 
 |  * on addition. | 
 |  * | 
 |  *                              16-bit | 
 |  *                              offset | 
 |  *                              ------ | 
 |  *     (v0, v1) <- 1            0.      const-wide/16 v0, #+1 | 
 |  *     (v2, v3) <- 2            2.      const-wide/16 v2, #+2 | 
 |  *     (v4, v5) <- | 
 |  *       (v0, v1) + (v1, v2)    4.      add-long v4, v0, v2 | 
 |  *     return (v4, v5)          6.      return-wide v4 | 
 |  */ | 
 | TEST_F(ConstantFoldingTest, LongConstantFoldingOnAddition) { | 
 |   const std::vector<uint16_t> data = SIX_REGISTERS_CODE_ITEM( | 
 |     Instruction::CONST_WIDE_16 | 0 << 8, 1, | 
 |     Instruction::CONST_WIDE_16 | 2 << 8, 2, | 
 |     Instruction::ADD_LONG | 4 << 8, 0 | 2 << 8, | 
 |     Instruction::RETURN_WIDE | 4 << 8); | 
 |  | 
 |   std::string expected_before = | 
 |       "BasicBlock 0, succ: 1\n" | 
 |       "  2: LongConstant [4]\n" | 
 |       "  3: LongConstant [4]\n" | 
 |       "  0: SuspendCheck\n" | 
 |       "  1: Goto 1\n" | 
 |       "BasicBlock 1, pred: 0, succ: 2\n" | 
 |       "  4: Add(2, 3) [5]\n" | 
 |       "  5: Return(4)\n" | 
 |       "BasicBlock 2, pred: 1\n" | 
 |       "  6: Exit\n"; | 
 |  | 
 |   // Expected difference after constant folding. | 
 |   diff_t expected_cf_diff = { | 
 |     { "  2: LongConstant [4]\n",  "  2: LongConstant\n" }, | 
 |     { "  3: LongConstant [4]\n",  "  3: LongConstant\n" | 
 |                                   "  7: LongConstant [5]\n" }, | 
 |     { "  4: Add(2, 3) [5]\n",     removed }, | 
 |     { "  5: Return(4)\n",         "  5: Return(7)\n" } | 
 |   }; | 
 |   std::string expected_after_cf = Patch(expected_before, expected_cf_diff); | 
 |  | 
 |   // Check the value of the computed constant. | 
 |   auto check_after_cf = [](HGraph* graph) { | 
 |     HInstruction* inst = graph->GetBlocks()[1]->GetFirstInstruction()->InputAt(0); | 
 |     ASSERT_TRUE(inst->IsLongConstant()); | 
 |     ASSERT_EQ(inst->AsLongConstant()->GetValue(), 3); | 
 |   }; | 
 |  | 
 |   // Expected difference after dead code elimination. | 
 |   diff_t expected_dce_diff = { | 
 |     { "  2: LongConstant\n", removed }, | 
 |     { "  3: LongConstant\n", removed } | 
 |   }; | 
 |   std::string expected_after_dce = Patch(expected_after_cf, expected_dce_diff); | 
 |  | 
 |   TestCode(data, | 
 |            expected_before, | 
 |            expected_after_cf, | 
 |            expected_after_dce, | 
 |            check_after_cf, | 
 |            DataType::Type::kInt64); | 
 | } | 
 |  | 
 | /** | 
 |  * Tiny three-register-pair program exercising long constant folding | 
 |  * on subtraction. | 
 |  * | 
 |  *                              16-bit | 
 |  *                              offset | 
 |  *                              ------ | 
 |  *     (v0, v1) <- 3            0.      const-wide/16 v0, #+3 | 
 |  *     (v2, v3) <- 2            2.      const-wide/16 v2, #+2 | 
 |  *     (v4, v5) <- | 
 |  *       (v0, v1) - (v1, v2)    4.      sub-long v4, v0, v2 | 
 |  *     return (v4, v5)          6.      return-wide v4 | 
 |  */ | 
 | TEST_F(ConstantFoldingTest, LongConstantFoldingOnSubtraction) { | 
 |   const std::vector<uint16_t> data = SIX_REGISTERS_CODE_ITEM( | 
 |     Instruction::CONST_WIDE_16 | 0 << 8, 3, | 
 |     Instruction::CONST_WIDE_16 | 2 << 8, 2, | 
 |     Instruction::SUB_LONG | 4 << 8, 0 | 2 << 8, | 
 |     Instruction::RETURN_WIDE | 4 << 8); | 
 |  | 
 |   std::string expected_before = | 
 |       "BasicBlock 0, succ: 1\n" | 
 |       "  2: LongConstant [4]\n" | 
 |       "  3: LongConstant [4]\n" | 
 |       "  0: SuspendCheck\n" | 
 |       "  1: Goto 1\n" | 
 |       "BasicBlock 1, pred: 0, succ: 2\n" | 
 |       "  4: Sub(2, 3) [5]\n" | 
 |       "  5: Return(4)\n" | 
 |       "BasicBlock 2, pred: 1\n" | 
 |       "  6: Exit\n"; | 
 |  | 
 |   // Expected difference after constant folding. | 
 |   diff_t expected_cf_diff = { | 
 |     { "  2: LongConstant [4]\n",  "  2: LongConstant\n" }, | 
 |     { "  3: LongConstant [4]\n",  "  3: LongConstant\n" | 
 |                                   "  7: LongConstant [5]\n" }, | 
 |     { "  4: Sub(2, 3) [5]\n",     removed }, | 
 |     { "  5: Return(4)\n",         "  5: Return(7)\n" } | 
 |   }; | 
 |   std::string expected_after_cf = Patch(expected_before, expected_cf_diff); | 
 |  | 
 |   // Check the value of the computed constant. | 
 |   auto check_after_cf = [](HGraph* graph) { | 
 |     HInstruction* inst = graph->GetBlocks()[1]->GetFirstInstruction()->InputAt(0); | 
 |     ASSERT_TRUE(inst->IsLongConstant()); | 
 |     ASSERT_EQ(inst->AsLongConstant()->GetValue(), 1); | 
 |   }; | 
 |  | 
 |   // Expected difference after dead code elimination. | 
 |   diff_t expected_dce_diff = { | 
 |     { "  2: LongConstant\n", removed }, | 
 |     { "  3: LongConstant\n", removed } | 
 |   }; | 
 |   std::string expected_after_dce = Patch(expected_after_cf, expected_dce_diff); | 
 |  | 
 |   TestCode(data, | 
 |            expected_before, | 
 |            expected_after_cf, | 
 |            expected_after_dce, | 
 |            check_after_cf, | 
 |            DataType::Type::kInt64); | 
 | } | 
 |  | 
 | /** | 
 |  * Three-register program with jumps leading to the creation of many | 
 |  * blocks. | 
 |  * | 
 |  * The intent of this test is to ensure that all constant expressions | 
 |  * are actually evaluated at compile-time, thanks to the reverse | 
 |  * (forward) post-order traversal of the the dominator tree. | 
 |  * | 
 |  *                              16-bit | 
 |  *                              offset | 
 |  *                              ------ | 
 |  *     v0 <- 1                   0.     const/4 v0, #+1 | 
 |  *     v1 <- 2                   1.     const/4 v1, #+2 | 
 |  *     v2 <- v0 + v1             2.     add-int v2, v0, v1 | 
 |  *     goto L2                   4.     goto +4 | 
 |  * L1: v1 <- v0 + 5              5.     add-int/lit16 v1, v0, #+5 | 
 |  *     goto L3                   7.     goto +4 | 
 |  * L2: v0 <- v2 + 4              8.     add-int/lit16 v0, v2, #+4 | 
 |  *     goto L1                  10.     goto +(-5) | 
 |  * L3: v2 <- v1 + 8             11.     add-int/lit16 v2, v1, #+8 | 
 |  *     return v2                13.     return v2 | 
 |  */ | 
 | TEST_F(ConstantFoldingTest, IntConstantFoldingAndJumps) { | 
 |   const std::vector<uint16_t> data = THREE_REGISTERS_CODE_ITEM( | 
 |     Instruction::CONST_4 | 0 << 8 | 1 << 12, | 
 |     Instruction::CONST_4 | 1 << 8 | 2 << 12, | 
 |     Instruction::ADD_INT | 2 << 8, 0 | 1 << 8, | 
 |     Instruction::GOTO | 4 << 8, | 
 |     Instruction::ADD_INT_LIT16 | 1 << 8 | 0 << 12, 5, | 
 |     Instruction::GOTO | 4 << 8, | 
 |     Instruction::ADD_INT_LIT16 | 0 << 8 | 2 << 12, 4, | 
 |     static_cast<uint16_t>(Instruction::GOTO | 0xFFFFFFFB << 8), | 
 |     Instruction::ADD_INT_LIT16 | 2 << 8 | 1 << 12, 8, | 
 |     Instruction::RETURN | 2 << 8); | 
 |  | 
 |   std::string expected_before = | 
 |       "BasicBlock 0, succ: 1\n" | 
 |       "  2: IntConstant [4]\n"             // v0 <- 1 | 
 |       "  3: IntConstant [4]\n"             // v1 <- 2 | 
 |       "  6: IntConstant [7]\n"             // const 5 | 
 |       "  9: IntConstant [10]\n"            // const 4 | 
 |       "  12: IntConstant [13]\n"           // const 8 | 
 |       "  0: SuspendCheck\n" | 
 |       "  1: Goto 1\n" | 
 |       "BasicBlock 1, pred: 0, succ: 3\n" | 
 |       "  4: Add(2, 3) [7]\n"               // v2 <- v0 + v1 = 1 + 2 = 3 | 
 |       "  5: Goto 3\n"                      // goto L2 | 
 |       "BasicBlock 2, pred: 3, succ: 4\n"   // L1: | 
 |       "  10: Add(7, 9) [13]\n"             // v1 <- v0 + 3 = 7 + 5 = 12 | 
 |       "  11: Goto 4\n"                     // goto L3 | 
 |       "BasicBlock 3, pred: 1, succ: 2\n"   // L2: | 
 |       "  7: Add(4, 6) [10]\n"              // v0 <- v2 + 2 = 3 + 4 = 7 | 
 |       "  8: Goto 2\n"                      // goto L1 | 
 |       "BasicBlock 4, pred: 2, succ: 5\n"   // L3: | 
 |       "  13: Add(10, 12) [14]\n"           // v2 <- v1 + 4 = 12 + 8 = 20 | 
 |       "  14: Return(13)\n"                 // return v2 | 
 |       "BasicBlock 5, pred: 4\n" | 
 |       "  15: Exit\n"; | 
 |  | 
 |   // Expected difference after constant folding. | 
 |   diff_t expected_cf_diff = { | 
 |     { "  2: IntConstant [4]\n",   "  2: IntConstant\n" }, | 
 |     { "  3: IntConstant [4]\n",   "  3: IntConstant\n" }, | 
 |     { "  6: IntConstant [7]\n",   "  6: IntConstant\n" }, | 
 |     { "  9: IntConstant [10]\n",  "  9: IntConstant\n" }, | 
 |     { "  12: IntConstant [13]\n", "  12: IntConstant\n" | 
 |                                   "  16: IntConstant\n" | 
 |                                   "  17: IntConstant\n" | 
 |                                   "  18: IntConstant\n" | 
 |                                   "  19: IntConstant [14]\n" }, | 
 |     { "  4: Add(2, 3) [7]\n",     removed }, | 
 |     { "  10: Add(7, 9) [13]\n",   removed }, | 
 |     { "  7: Add(4, 6) [10]\n",    removed }, | 
 |     { "  13: Add(10, 12) [14]\n", removed }, | 
 |     { "  14: Return(13)\n",       "  14: Return(19)\n"} | 
 |   }; | 
 |   std::string expected_after_cf = Patch(expected_before, expected_cf_diff); | 
 |  | 
 |   // Check the values of the computed constants. | 
 |   auto check_after_cf = [](HGraph* graph) { | 
 |     HInstruction* inst1 = graph->GetBlocks()[4]->GetFirstInstruction()->InputAt(0); | 
 |     ASSERT_TRUE(inst1->IsIntConstant()); | 
 |     ASSERT_EQ(inst1->AsIntConstant()->GetValue(), 20); | 
 |     HInstruction* inst2 = inst1->GetPrevious(); | 
 |     ASSERT_TRUE(inst2->IsIntConstant()); | 
 |     ASSERT_EQ(inst2->AsIntConstant()->GetValue(), 12); | 
 |     HInstruction* inst3 = inst2->GetPrevious(); | 
 |     ASSERT_TRUE(inst3->IsIntConstant()); | 
 |     ASSERT_EQ(inst3->AsIntConstant()->GetValue(), 7); | 
 |     HInstruction* inst4 = inst3->GetPrevious(); | 
 |     ASSERT_TRUE(inst4->IsIntConstant()); | 
 |     ASSERT_EQ(inst4->AsIntConstant()->GetValue(), 3); | 
 |   }; | 
 |  | 
 |   // Expected difference after dead code elimination. | 
 |   std::string expected_after_dce = | 
 |       "BasicBlock 0, succ: 1\n" | 
 |       "  19: IntConstant [14]\n" | 
 |       "  0: SuspendCheck\n" | 
 |       "  1: Goto 1\n" | 
 |       "BasicBlock 1, pred: 0, succ: 5\n" | 
 |       "  14: Return(19)\n" | 
 |       "BasicBlock 5, pred: 1\n" | 
 |       "  15: Exit\n"; | 
 |  | 
 |   TestCode(data, | 
 |            expected_before, | 
 |            expected_after_cf, | 
 |            expected_after_dce, | 
 |            check_after_cf); | 
 | } | 
 |  | 
 | /** | 
 |  * Three-register program with a constant (static) condition. | 
 |  * | 
 |  *                              16-bit | 
 |  *                              offset | 
 |  *                              ------ | 
 |  *     v1 <- 1                  0.      const/4 v1, #+1 | 
 |  *     v0 <- 0                  1.      const/4 v0, #+0 | 
 |  *     if v1 >= 0 goto L1       2.      if-gez v1, +3 | 
 |  *     v0 <- v1                 4.      move v0, v1 | 
 |  * L1: v2 <- v0 + v1            5.      add-int v2, v0, v1 | 
 |  *     return-void              7.      return | 
 |  */ | 
 | TEST_F(ConstantFoldingTest, ConstantCondition) { | 
 |   const std::vector<uint16_t> data = THREE_REGISTERS_CODE_ITEM( | 
 |     Instruction::CONST_4 | 1 << 8 | 1 << 12, | 
 |     Instruction::CONST_4 | 0 << 8 | 0 << 12, | 
 |     Instruction::IF_GEZ | 1 << 8, 3, | 
 |     Instruction::MOVE | 0 << 8 | 1 << 12, | 
 |     Instruction::ADD_INT | 2 << 8, 0 | 1 << 8, | 
 |     Instruction::RETURN_VOID); | 
 |  | 
 |   std::string expected_before = | 
 |       "BasicBlock 0, succ: 1\n" | 
 |       "  3: IntConstant [9, 8, 5]\n" | 
 |       "  4: IntConstant [8, 5]\n" | 
 |       "  1: SuspendCheck\n" | 
 |       "  2: Goto 1\n" | 
 |       "BasicBlock 1, pred: 0, succ: 5, 2\n" | 
 |       "  5: GreaterThanOrEqual(3, 4) [6]\n" | 
 |       "  6: If(5)\n" | 
 |       "BasicBlock 2, pred: 1, succ: 3\n" | 
 |       "  7: Goto 3\n" | 
 |       "BasicBlock 3, pred: 5, 2, succ: 4\n" | 
 |       "  8: Phi(4, 3) [9]\n" | 
 |       "  9: Add(8, 3)\n" | 
 |       "  10: ReturnVoid\n" | 
 |       "BasicBlock 4, pred: 3\n" | 
 |       "  11: Exit\n" | 
 |       "BasicBlock 5, pred: 1, succ: 3\n" | 
 |       "  0: Goto 3\n"; | 
 |  | 
 |   // Expected difference after constant folding. | 
 |   diff_t expected_cf_diff = { | 
 |     { "  3: IntConstant [9, 8, 5]\n",        "  3: IntConstant [6, 9, 8]\n" }, | 
 |     { "  4: IntConstant [8, 5]\n",           "  4: IntConstant [8]\n" }, | 
 |     { "  5: GreaterThanOrEqual(3, 4) [6]\n", removed }, | 
 |     { "  6: If(5)\n",                        "  6: If(3)\n" } | 
 |   }; | 
 |   std::string expected_after_cf = Patch(expected_before, expected_cf_diff); | 
 |  | 
 |   // Check the values of the computed constants. | 
 |   auto check_after_cf = [](HGraph* graph) { | 
 |     HInstruction* inst = graph->GetBlocks()[1]->GetFirstInstruction()->InputAt(0); | 
 |     ASSERT_TRUE(inst->IsIntConstant()); | 
 |     ASSERT_EQ(inst->AsIntConstant()->GetValue(), 1); | 
 |   }; | 
 |  | 
 |   // Expected graph after dead code elimination. | 
 |   std::string expected_after_dce = | 
 |       "BasicBlock 0, succ: 1\n" | 
 |       "  1: SuspendCheck\n" | 
 |       "  2: Goto 1\n" | 
 |       "BasicBlock 1, pred: 0, succ: 4\n" | 
 |       "  10: ReturnVoid\n" | 
 |       "BasicBlock 4, pred: 1\n" | 
 |       "  11: Exit\n"; | 
 |  | 
 |   TestCode(data, | 
 |            expected_before, | 
 |            expected_after_cf, | 
 |            expected_after_dce, | 
 |            check_after_cf); | 
 | } | 
 |  | 
 | /** | 
 |  * Unsigned comparisons with zero. Since these instructions are not present | 
 |  * in the bytecode, we need to set up the graph explicitly. | 
 |  */ | 
 | TEST_F(ConstantFoldingTest, UnsignedComparisonsWithZero) { | 
 |   graph_ = CreateGraph(); | 
 |   HBasicBlock* entry_block = new (GetAllocator()) HBasicBlock(graph_); | 
 |   graph_->AddBlock(entry_block); | 
 |   graph_->SetEntryBlock(entry_block); | 
 |   HBasicBlock* block = new (GetAllocator()) HBasicBlock(graph_); | 
 |   graph_->AddBlock(block); | 
 |   HBasicBlock* exit_block = new (GetAllocator()) HBasicBlock(graph_); | 
 |   graph_->AddBlock(exit_block); | 
 |   graph_->SetExitBlock(exit_block); | 
 |   entry_block->AddSuccessor(block); | 
 |   block->AddSuccessor(exit_block); | 
 |  | 
 |   // Make various unsigned comparisons with zero against a parameter. | 
 |   HInstruction* parameter = new (GetAllocator()) HParameterValue( | 
 |       graph_->GetDexFile(), dex::TypeIndex(0), 0, DataType::Type::kInt32, true); | 
 |   entry_block->AddInstruction(parameter); | 
 |   entry_block->AddInstruction(new (GetAllocator()) HGoto()); | 
 |  | 
 |   HInstruction* zero = graph_->GetIntConstant(0); | 
 |  | 
 |   HInstruction* last; | 
 |   block->AddInstruction(last = new (GetAllocator()) HAbove(zero, parameter)); | 
 |   block->AddInstruction(new (GetAllocator()) HSelect(last, parameter, parameter, 0)); | 
 |   block->AddInstruction(last = new (GetAllocator()) HAbove(parameter, zero)); | 
 |   block->AddInstruction(new (GetAllocator()) HSelect(last, parameter, parameter, 0)); | 
 |   block->AddInstruction(last = new (GetAllocator()) HAboveOrEqual(zero, parameter)); | 
 |   block->AddInstruction(new (GetAllocator()) HSelect(last, parameter, parameter, 0)); | 
 |   block->AddInstruction(last = new (GetAllocator()) HAboveOrEqual(parameter, zero)); | 
 |   block->AddInstruction(new (GetAllocator()) HSelect(last, parameter, parameter, 0)); | 
 |   block->AddInstruction(last = new (GetAllocator()) HBelow(zero, parameter)); | 
 |   block->AddInstruction(new (GetAllocator()) HSelect(last, parameter, parameter, 0)); | 
 |   block->AddInstruction(last = new (GetAllocator()) HBelow(parameter, zero)); | 
 |   block->AddInstruction(new (GetAllocator()) HSelect(last, parameter, parameter, 0)); | 
 |   block->AddInstruction(last = new (GetAllocator()) HBelowOrEqual(zero, parameter)); | 
 |   block->AddInstruction(new (GetAllocator()) HSelect(last, parameter, parameter, 0)); | 
 |   block->AddInstruction(last = new (GetAllocator()) HBelowOrEqual(parameter, zero)); | 
 |   block->AddInstruction(new (GetAllocator()) HSelect(last, parameter, parameter, 0)); | 
 |   block->AddInstruction(new (GetAllocator()) HReturn(zero)); | 
 |  | 
 |   exit_block->AddInstruction(new (GetAllocator()) HExit()); | 
 |  | 
 |   graph_->BuildDominatorTree(); | 
 |  | 
 |   const std::string expected_before = | 
 |       "BasicBlock 0, succ: 1\n" | 
 |       "  0: ParameterValue [18, 18, 17, 16, 16, 15, 14, 14, 13, 12, 12, 11, 10, 10, 9, " | 
 |                             "8, 8, 7, 6, 6, 5, 4, 4, 3]\n" | 
 |       "  2: IntConstant [19, 17, 15, 13, 11, 9, 7, 5, 3]\n" | 
 |       "  1: Goto 1\n" | 
 |       "BasicBlock 1, pred: 0, succ: 2\n" | 
 |       "  3: Above(2, 0) [4]\n" | 
 |       "  4: Select(0, 0, 3)\n" | 
 |       "  5: Above(0, 2) [6]\n" | 
 |       "  6: Select(0, 0, 5)\n" | 
 |       "  7: AboveOrEqual(2, 0) [8]\n" | 
 |       "  8: Select(0, 0, 7)\n" | 
 |       "  9: AboveOrEqual(0, 2) [10]\n" | 
 |       "  10: Select(0, 0, 9)\n" | 
 |       "  11: Below(2, 0) [12]\n" | 
 |       "  12: Select(0, 0, 11)\n" | 
 |       "  13: Below(0, 2) [14]\n" | 
 |       "  14: Select(0, 0, 13)\n" | 
 |       "  15: BelowOrEqual(2, 0) [16]\n" | 
 |       "  16: Select(0, 0, 15)\n" | 
 |       "  17: BelowOrEqual(0, 2) [18]\n" | 
 |       "  18: Select(0, 0, 17)\n" | 
 |       "  19: Return(2)\n" | 
 |       "BasicBlock 2, pred: 1\n" | 
 |       "  20: Exit\n"; | 
 |  | 
 |   const std::string expected_after_cf = | 
 |       "BasicBlock 0, succ: 1\n" | 
 |       "  0: ParameterValue [18, 18, 17, 16, 16, 14, 14, 12, 12, 11, 10, 10, " | 
 |                             "8, 8, 7, 6, 6, 5, 4, 4]\n" | 
 |       "  2: IntConstant [14, 4, 19, 17, 11, 7, 5]\n" | 
 |       "  21: IntConstant [16, 10]\n" | 
 |       "  1: Goto 1\n" | 
 |       "BasicBlock 1, pred: 0, succ: 2\n" | 
 |       "  4: Select(0, 0, 2)\n" | 
 |       "  5: Above(0, 2) [6]\n" | 
 |       "  6: Select(0, 0, 5)\n" | 
 |       "  7: AboveOrEqual(2, 0) [8]\n" | 
 |       "  8: Select(0, 0, 7)\n" | 
 |       "  10: Select(0, 0, 21)\n" | 
 |       "  11: Below(2, 0) [12]\n" | 
 |       "  12: Select(0, 0, 11)\n" | 
 |       "  14: Select(0, 0, 2)\n" | 
 |       "  16: Select(0, 0, 21)\n" | 
 |       "  17: BelowOrEqual(0, 2) [18]\n" | 
 |       "  18: Select(0, 0, 17)\n" | 
 |       "  19: Return(2)\n" | 
 |       "BasicBlock 2, pred: 1\n" | 
 |       "  20: Exit\n"; | 
 |  | 
 |   const std::string expected_after_dce = | 
 |       "BasicBlock 0, succ: 1\n" | 
 |       "  0: ParameterValue\n" | 
 |       "  2: IntConstant [19]\n" | 
 |       "  1: Goto 1\n" | 
 |       "BasicBlock 1, pred: 0, succ: 2\n" | 
 |       "  19: Return(2)\n" | 
 |       "BasicBlock 2, pred: 1\n" | 
 |       "  20: Exit\n"; | 
 |  | 
 |   auto check_after_cf = [](HGraph* graph) { | 
 |     CHECK(graph != nullptr); | 
 |   }; | 
 |  | 
 |   TestCodeOnReadyGraph(expected_before, | 
 |                        expected_after_cf, | 
 |                        expected_after_dce, | 
 |                        check_after_cf); | 
 | } | 
 |  | 
 | }  // namespace art |