v8/test/unittests/compiler/liveness-analyzer-unittest.cc
leszeks 0c1727ad79 [ignition/turbo] Add liveness analysis for the accumulator
Adds a boolean flag to the liveness analysis which makes it also analyze
the accumulator. This can help prevent the accumulator escaping loops,
as well as decreasing the number of distinct state values nodes in the
graph.

The flag is a kind of ugly way to hack this in, however it is probably
the simplest to add, and (more importantly) to remove once the AST graph
builder is gone.

I measure a 2.6% improvement on Mandreel on my x64 machine, and a ~2%
improvement on Navier-Stokes. Other improvements are expected.

Review-Url: https://codereview.chromium.org/2428503002
Cr-Commit-Position: refs/heads/master@{#40359}
2016-10-17 11:48:04 +00:00

379 lines
11 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 "src/compiler/js-graph.h"
#include "src/compiler/linkage.h"
#include "src/compiler/liveness-analyzer.h"
#include "src/compiler/node-matchers.h"
#include "src/compiler/state-values-utils.h"
#include "test/unittests/compiler/graph-unittest.h"
#include "test/unittests/compiler/node-test-utils.h"
using testing::MakeMatcher;
using testing::MatcherInterface;
using testing::MatchResultListener;
using testing::StringMatchResultListener;
namespace v8 {
namespace internal {
namespace compiler {
class LivenessAnalysisTest : public GraphTest {
public:
explicit LivenessAnalysisTest(int locals_count = 4)
: locals_count_(locals_count),
machine_(zone(), MachineRepresentation::kWord32),
javascript_(zone()),
jsgraph_(isolate(), graph(), common(), &javascript_, nullptr,
&machine_),
analyzer_(locals_count, false, zone()),
empty_values_(graph()->NewNode(common()->StateValues(0), 0, nullptr)),
next_checkpoint_id_(0),
current_block_(nullptr) {}
protected:
JSGraph* jsgraph() { return &jsgraph_; }
LivenessAnalyzer* analyzer() { return &analyzer_; }
void Run() {
StateValuesCache cache(jsgraph());
NonLiveFrameStateSlotReplacer replacer(
&cache, jsgraph()->UndefinedConstant(), analyzer()->local_count(),
false, zone());
analyzer()->Run(&replacer);
}
Node* Checkpoint() {
int ast_num = next_checkpoint_id_++;
int first_const = intconst_from_bailout_id(ast_num, locals_count_);
const Operator* locals_op = common()->StateValues(locals_count_);
ZoneVector<Node*> local_inputs(locals_count_, nullptr, zone());
for (int i = 0; i < locals_count_; i++) {
local_inputs[i] = jsgraph()->Int32Constant(i + first_const);
}
Node* locals =
graph()->NewNode(locals_op, locals_count_, &local_inputs.front());
const FrameStateFunctionInfo* state_info =
common()->CreateFrameStateFunctionInfo(
FrameStateType::kJavaScriptFunction, 0, locals_count_,
Handle<SharedFunctionInfo>());
const Operator* op = common()->FrameState(
BailoutId(ast_num), OutputFrameStateCombine::Ignore(), state_info);
Node* result =
graph()->NewNode(op, empty_values_, locals, empty_values_,
jsgraph()->UndefinedConstant(),
jsgraph()->UndefinedConstant(), graph()->start());
current_block_->Checkpoint(result);
return result;
}
void Bind(int var) { current_block()->Bind(var); }
void Lookup(int var) { current_block()->Lookup(var); }
class CheckpointMatcher : public MatcherInterface<Node*> {
public:
explicit CheckpointMatcher(const char* liveness, Node* empty_values,
int locals_count, Node* replacement)
: liveness_(liveness),
empty_values_(empty_values),
locals_count_(locals_count),
replacement_(replacement) {}
void DescribeTo(std::ostream* os) const override {
*os << "is a frame state with '" << liveness_
<< "' liveness, empty "
"parameters and empty expression stack";
}
bool MatchAndExplain(Node* frame_state,
MatchResultListener* listener) const override {
if (frame_state == NULL) {
*listener << "which is NULL";
return false;
}
DCHECK(frame_state->opcode() == IrOpcode::kFrameState);
FrameStateInfo state_info = OpParameter<FrameStateInfo>(frame_state);
int ast_num = state_info.bailout_id().ToInt();
int first_const = intconst_from_bailout_id(ast_num, locals_count_);
if (empty_values_ != frame_state->InputAt(0)) {
*listener << "whose parameters are " << frame_state->InputAt(0)
<< " but should have been " << empty_values_ << " (empty)";
return false;
}
if (empty_values_ != frame_state->InputAt(2)) {
*listener << "whose expression stack is " << frame_state->InputAt(2)
<< " but should have been " << empty_values_ << " (empty)";
return false;
}
StateValuesAccess locals(frame_state->InputAt(1));
if (locals_count_ != static_cast<int>(locals.size())) {
*listener << "whose number of locals is " << locals.size()
<< " but should have been " << locals_count_;
return false;
}
int i = 0;
for (StateValuesAccess::TypedNode value : locals) {
if (liveness_[i] == 'L') {
StringMatchResultListener value_listener;
if (value.node == replacement_) {
*listener << "whose local #" << i << " was " << value.node->opcode()
<< " but should have been 'undefined'";
return false;
} else if (!IsInt32Constant(first_const + i)
.MatchAndExplain(value.node, &value_listener)) {
*listener << "whose local #" << i << " does not match";
if (value_listener.str() != "") {
*listener << ", " << value_listener.str();
}
return false;
}
} else if (liveness_[i] == '.') {
if (value.node != replacement_) {
*listener << "whose local #" << i << " is " << value.node
<< " but should have been " << replacement_
<< " (undefined)";
return false;
}
} else {
UNREACHABLE();
}
i++;
}
return true;
}
private:
const char* liveness_;
Node* empty_values_;
int locals_count_;
Node* replacement_;
};
Matcher<Node*> IsCheckpointModuloLiveness(const char* liveness) {
return MakeMatcher(new CheckpointMatcher(liveness, empty_values_,
locals_count_,
jsgraph()->UndefinedConstant()));
}
LivenessAnalyzerBlock* current_block() { return current_block_; }
void set_current_block(LivenessAnalyzerBlock* block) {
current_block_ = block;
}
private:
static int intconst_from_bailout_id(int ast_num, int locals_count) {
return (locals_count + 1) * ast_num + 1;
}
int locals_count_;
MachineOperatorBuilder machine_;
JSOperatorBuilder javascript_;
JSGraph jsgraph_;
LivenessAnalyzer analyzer_;
Node* empty_values_;
int next_checkpoint_id_;
LivenessAnalyzerBlock* current_block_;
};
TEST_F(LivenessAnalysisTest, EmptyBlock) {
set_current_block(analyzer()->NewBlock());
Node* c1 = Checkpoint();
Run();
// Nothing is live.
EXPECT_THAT(c1, IsCheckpointModuloLiveness("...."));
}
TEST_F(LivenessAnalysisTest, SimpleLookup) {
set_current_block(analyzer()->NewBlock());
Node* c1 = Checkpoint();
Lookup(1);
Node* c2 = Checkpoint();
Run();
EXPECT_THAT(c1, IsCheckpointModuloLiveness(".L.."));
EXPECT_THAT(c2, IsCheckpointModuloLiveness("...."));
}
TEST_F(LivenessAnalysisTest, DiamondLookups) {
// Start block.
LivenessAnalyzerBlock* start = analyzer()->NewBlock();
set_current_block(start);
Node* c1_start = Checkpoint();
// First branch.
LivenessAnalyzerBlock* b1 = analyzer()->NewBlock(start);
set_current_block(b1);
Node* c1_b1 = Checkpoint();
Lookup(1);
Node* c2_b1 = Checkpoint();
Lookup(3);
Node* c3_b1 = Checkpoint();
// Second branch.
LivenessAnalyzerBlock* b2 = analyzer()->NewBlock(start);
set_current_block(b2);
Node* c1_b2 = Checkpoint();
Lookup(3);
Node* c2_b2 = Checkpoint();
Lookup(2);
Node* c3_b2 = Checkpoint();
// Merge block.
LivenessAnalyzerBlock* m = analyzer()->NewBlock(b1);
m->AddPredecessor(b2);
set_current_block(m);
Node* c1_m = Checkpoint();
Lookup(0);
Node* c2_m = Checkpoint();
Run();
EXPECT_THAT(c1_start, IsCheckpointModuloLiveness("LLLL"));
EXPECT_THAT(c1_b1, IsCheckpointModuloLiveness("LL.L"));
EXPECT_THAT(c2_b1, IsCheckpointModuloLiveness("L..L"));
EXPECT_THAT(c3_b1, IsCheckpointModuloLiveness("L..."));
EXPECT_THAT(c1_b2, IsCheckpointModuloLiveness("L.LL"));
EXPECT_THAT(c2_b2, IsCheckpointModuloLiveness("L.L."));
EXPECT_THAT(c3_b2, IsCheckpointModuloLiveness("L..."));
EXPECT_THAT(c1_m, IsCheckpointModuloLiveness("L..."));
EXPECT_THAT(c2_m, IsCheckpointModuloLiveness("...."));
}
TEST_F(LivenessAnalysisTest, DiamondLookupsAndBinds) {
// Start block.
LivenessAnalyzerBlock* start = analyzer()->NewBlock();
set_current_block(start);
Node* c1_start = Checkpoint();
Bind(0);
Node* c2_start = Checkpoint();
// First branch.
LivenessAnalyzerBlock* b1 = analyzer()->NewBlock(start);
set_current_block(b1);
Node* c1_b1 = Checkpoint();
Bind(2);
Bind(1);
Node* c2_b1 = Checkpoint();
Bind(3);
Node* c3_b1 = Checkpoint();
// Second branch.
LivenessAnalyzerBlock* b2 = analyzer()->NewBlock(start);
set_current_block(b2);
Node* c1_b2 = Checkpoint();
Lookup(2);
Node* c2_b2 = Checkpoint();
Bind(2);
Bind(3);
Node* c3_b2 = Checkpoint();
// Merge block.
LivenessAnalyzerBlock* m = analyzer()->NewBlock(b1);
m->AddPredecessor(b2);
set_current_block(m);
Node* c1_m = Checkpoint();
Lookup(0);
Lookup(1);
Lookup(2);
Lookup(3);
Node* c2_m = Checkpoint();
Run();
EXPECT_THAT(c1_start, IsCheckpointModuloLiveness(".LL."));
EXPECT_THAT(c2_start, IsCheckpointModuloLiveness("LLL."));
EXPECT_THAT(c1_b1, IsCheckpointModuloLiveness("L..."));
EXPECT_THAT(c2_b1, IsCheckpointModuloLiveness("LLL."));
EXPECT_THAT(c3_b1, IsCheckpointModuloLiveness("LLLL"));
EXPECT_THAT(c1_b2, IsCheckpointModuloLiveness("LLL."));
EXPECT_THAT(c2_b2, IsCheckpointModuloLiveness("LL.."));
EXPECT_THAT(c3_b2, IsCheckpointModuloLiveness("LLLL"));
EXPECT_THAT(c1_m, IsCheckpointModuloLiveness("LLLL"));
EXPECT_THAT(c2_m, IsCheckpointModuloLiveness("...."));
}
TEST_F(LivenessAnalysisTest, SimpleLoop) {
// Start block.
LivenessAnalyzerBlock* start = analyzer()->NewBlock();
set_current_block(start);
Node* c1_start = Checkpoint();
Bind(0);
Bind(1);
Bind(2);
Bind(3);
Node* c2_start = Checkpoint();
// Loop header block.
LivenessAnalyzerBlock* header = analyzer()->NewBlock(start);
set_current_block(header);
Node* c1_header = Checkpoint();
Lookup(0);
Bind(2);
Node* c2_header = Checkpoint();
// Inside-loop block.
LivenessAnalyzerBlock* in_loop = analyzer()->NewBlock(header);
set_current_block(in_loop);
Node* c1_in_loop = Checkpoint();
Bind(0);
Lookup(3);
Node* c2_in_loop = Checkpoint();
// Add back edge.
header->AddPredecessor(in_loop);
// After-loop block.
LivenessAnalyzerBlock* end = analyzer()->NewBlock(header);
set_current_block(end);
Node* c1_end = Checkpoint();
Lookup(1);
Lookup(2);
Node* c2_end = Checkpoint();
Run();
EXPECT_THAT(c1_start, IsCheckpointModuloLiveness("...."));
EXPECT_THAT(c2_start, IsCheckpointModuloLiveness("LL.L"));
EXPECT_THAT(c1_header, IsCheckpointModuloLiveness("LL.L"));
EXPECT_THAT(c2_header, IsCheckpointModuloLiveness(".LLL"));
EXPECT_THAT(c1_in_loop, IsCheckpointModuloLiveness(".L.L"));
EXPECT_THAT(c2_in_loop, IsCheckpointModuloLiveness("LL.L"));
EXPECT_THAT(c1_end, IsCheckpointModuloLiveness(".LL."));
EXPECT_THAT(c2_end, IsCheckpointModuloLiveness("...."));
}
} // namespace compiler
} // namespace internal
} // namespace v8