/*
* 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 "arch/x86/instruction_set_features_x86.h"
#include "code_generator_x86.h"
#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 CommonCompilerTest {
public:
ConstantFoldingTest() : pool_(), allocator_(&pool_) {
graph_ = CreateGraph(&allocator_);
}
void TestCode(const 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,
Primitive::Type return_type = Primitive::kPrimInt) {
graph_ = CreateCFG(&allocator_, 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);
std::unique_ptr<const X86InstructionSetFeatures> features_x86(
X86InstructionSetFeatures::FromCppDefines());
x86::CodeGeneratorX86 codegenX86(graph_, *features_x86.get(), CompilerOptions());
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);
}
ArenaPool pool_;
ArenaAllocator allocator_;
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 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 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,
Primitive::kPrimLong);
}
/**
* 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 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 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 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 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,
Primitive::kPrimLong);
}
/**
* 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 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,
Primitive::kPrimLong);
}
/**
* 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 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 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(&allocator_);
HBasicBlock* entry_block = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(entry_block);
graph_->SetEntryBlock(entry_block);
HBasicBlock* block = new (&allocator_) HBasicBlock(graph_);
graph_->AddBlock(block);
HBasicBlock* exit_block = new (&allocator_) 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 (&allocator_) HParameterValue(
graph_->GetDexFile(), dex::TypeIndex(0), 0, Primitive::kPrimInt, true);
entry_block->AddInstruction(parameter);
entry_block->AddInstruction(new (&allocator_) HGoto());
HInstruction* zero = graph_->GetIntConstant(0);
HInstruction* last;
block->AddInstruction(last = new (&allocator_) HAbove(zero, parameter));
block->AddInstruction(new (&allocator_) HSelect(last, parameter, parameter, 0));
block->AddInstruction(last = new (&allocator_) HAbove(parameter, zero));
block->AddInstruction(new (&allocator_) HSelect(last, parameter, parameter, 0));
block->AddInstruction(last = new (&allocator_) HAboveOrEqual(zero, parameter));
block->AddInstruction(new (&allocator_) HSelect(last, parameter, parameter, 0));
block->AddInstruction(last = new (&allocator_) HAboveOrEqual(parameter, zero));
block->AddInstruction(new (&allocator_) HSelect(last, parameter, parameter, 0));
block->AddInstruction(last = new (&allocator_) HBelow(zero, parameter));
block->AddInstruction(new (&allocator_) HSelect(last, parameter, parameter, 0));
block->AddInstruction(last = new (&allocator_) HBelow(parameter, zero));
block->AddInstruction(new (&allocator_) HSelect(last, parameter, parameter, 0));
block->AddInstruction(last = new (&allocator_) HBelowOrEqual(zero, parameter));
block->AddInstruction(new (&allocator_) HSelect(last, parameter, parameter, 0));
block->AddInstruction(last = new (&allocator_) HBelowOrEqual(parameter, zero));
block->AddInstruction(new (&allocator_) HSelect(last, parameter, parameter, 0));
block->AddInstruction(new (&allocator_) HReturn(zero));
exit_block->AddInstruction(new (&allocator_) 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