v8/test/unittests/compiler/value-numbering-reducer-unittest.cc
bmeurer@chromium.org db33f07f79 [turbofan] Reenable value numbering.
Value numbering is now limited to eliminatable operators (i.e. operators
that don't throw and don't write), and uses linear probing instead of
separate chaining.

TEST=unittests
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/630423002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24452 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-10-08 08:06:59 +00:00

130 lines
4.1 KiB
C++

// Copyright 2014 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <limits>
#include "src/compiler/graph.h"
#include "src/compiler/value-numbering-reducer.h"
#include "test/unittests/test-utils.h"
namespace v8 {
namespace internal {
namespace compiler {
namespace {
const SimpleOperator kOp0(0, Operator::kEliminatable, 0, 1, "op0");
const SimpleOperator kOp1(1, Operator::kEliminatable, 1, 1, "op1");
} // namespace
class ValueNumberingReducerTest : public TestWithZone {
public:
ValueNumberingReducerTest() : graph_(zone()), reducer_(zone()) {}
protected:
Reduction Reduce(Node* node) { return reducer_.Reduce(node); }
Graph* graph() { return &graph_; }
private:
Graph graph_;
ValueNumberingReducer reducer_;
};
TEST_F(ValueNumberingReducerTest, AllInputsAreChecked) {
Node* na = graph()->NewNode(&kOp0);
Node* nb = graph()->NewNode(&kOp0);
Node* n1 = graph()->NewNode(&kOp0, na);
Node* n2 = graph()->NewNode(&kOp0, nb);
EXPECT_FALSE(Reduce(n1).Changed());
EXPECT_FALSE(Reduce(n2).Changed());
}
TEST_F(ValueNumberingReducerTest, DeadNodesAreNeverReturned) {
Node* n0 = graph()->NewNode(&kOp0);
Node* n1 = graph()->NewNode(&kOp1, n0);
EXPECT_FALSE(Reduce(n1).Changed());
n1->Kill();
EXPECT_FALSE(Reduce(graph()->NewNode(&kOp1, n0)).Changed());
}
TEST_F(ValueNumberingReducerTest, OnlyEliminatableNodesAreReduced) {
SimpleOperator op(0, Operator::kNoProperties, 0, 1, "op");
Node* n0 = graph()->NewNode(&op);
Node* n1 = graph()->NewNode(&op);
EXPECT_FALSE(Reduce(n0).Changed());
EXPECT_FALSE(Reduce(n1).Changed());
}
TEST_F(ValueNumberingReducerTest, OperatorEqualityNotIdentity) {
static const size_t kMaxInputCount = 16;
Node* inputs[kMaxInputCount];
for (size_t i = 0; i < arraysize(inputs); ++i) {
Operator::Opcode opcode = static_cast<Operator::Opcode>(
std::numeric_limits<Operator::Opcode>::max() - i);
inputs[i] = graph()->NewNode(new (zone()) SimpleOperator(
opcode, Operator::kEliminatable, 0, 1, "Operator"));
}
TRACED_FORRANGE(size_t, input_count, 0, arraysize(inputs)) {
const SimpleOperator op1(static_cast<Operator::Opcode>(input_count),
Operator::kEliminatable,
static_cast<int>(input_count), 1, "op");
Node* n1 = graph()->NewNode(&op1, static_cast<int>(input_count), inputs);
Reduction r1 = Reduce(n1);
EXPECT_FALSE(r1.Changed());
const SimpleOperator op2(static_cast<Operator::Opcode>(input_count),
Operator::kEliminatable,
static_cast<int>(input_count), 1, "op");
Node* n2 = graph()->NewNode(&op2, static_cast<int>(input_count), inputs);
Reduction r2 = Reduce(n2);
EXPECT_TRUE(r2.Changed());
EXPECT_EQ(n1, r2.replacement());
}
}
TEST_F(ValueNumberingReducerTest, SubsequentReductionsYieldTheSameNode) {
static const size_t kMaxInputCount = 16;
Node* inputs[kMaxInputCount];
for (size_t i = 0; i < arraysize(inputs); ++i) {
Operator::Opcode opcode = static_cast<Operator::Opcode>(
std::numeric_limits<Operator::Opcode>::max() - i);
inputs[i] = graph()->NewNode(new (zone()) SimpleOperator(
opcode, Operator::kEliminatable, 0, 1, "Operator"));
}
TRACED_FORRANGE(size_t, input_count, 0, arraysize(inputs)) {
const SimpleOperator op1(1, Operator::kEliminatable,
static_cast<int>(input_count), 1, "op1");
Node* n = graph()->NewNode(&op1, static_cast<int>(input_count), inputs);
Reduction r = Reduce(n);
EXPECT_FALSE(r.Changed());
r = Reduce(graph()->NewNode(&op1, static_cast<int>(input_count), inputs));
ASSERT_TRUE(r.Changed());
EXPECT_EQ(n, r.replacement());
r = Reduce(graph()->NewNode(&op1, static_cast<int>(input_count), inputs));
ASSERT_TRUE(r.Changed());
EXPECT_EQ(n, r.replacement());
}
}
TEST_F(ValueNumberingReducerTest, WontReplaceNodeWithItself) {
Node* n = graph()->NewNode(&kOp0);
EXPECT_FALSE(Reduce(n).Changed());
EXPECT_FALSE(Reduce(n).Changed());
}
} // namespace compiler
} // namespace internal
} // namespace v8