blob: f483b05684cd2b7f86e33ce933484d2258a0516e [file] [log] [blame]
// Copyright (c) 2020, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "platform/assert.h"
#include "vm/compiler/backend/il_printer.h"
#include "vm/compiler/backend/il_test_helper.h"
#include "vm/unit_test.h"
namespace dart {
DEBUG_ONLY(DECLARE_FLAG(bool, trace_write_barrier_elimination);)
ISOLATE_UNIT_TEST_CASE(IRTest_WriteBarrierElimination_JoinSuccessors) {
DEBUG_ONLY(
SetFlagScope<bool> sfs(&FLAG_trace_write_barrier_elimination, true));
const char* nullable_tag = TestCase::NullableTag();
const char* null_assert_tag = TestCase::NullAssertTag();
// This is a regression test for a bug where we were using
// JoinEntry::SuccessorCount() to determine the number of outgoing blocks
// from the join block. JoinEntry::SuccessorCount() is in fact always 0;
// JoinEntry::last_instruction()->SuccessorCount() should be used instead.
// clang-format off
auto kScript = Utils::CStringUniquePtr(
OS::SCreate(nullptr, R"(
class C {
int%s value;
C%s next;
C%s prev;
}
@pragma("vm:never-inline")
fn() {}
foo(int x) {
C%s prev = C();
C%s next;
while (x --> 0) {
next = C();
next%s.prev = prev;
prev?.next = next;
prev = next;
fn();
}
return next;
}
main() { foo(10); }
)",
nullable_tag, nullable_tag, nullable_tag, nullable_tag,
nullable_tag, null_assert_tag), std::free);
// clang-format on
const auto& root_library = Library::Handle(LoadTestScript(kScript.get()));
Invoke(root_library, "main");
const auto& function = Function::Handle(GetFunction(root_library, "foo"));
TestPipeline pipeline(function, CompilerPass::kJIT);
FlowGraph* flow_graph = pipeline.RunPasses({});
auto entry = flow_graph->graph_entry()->normal_entry();
EXPECT(entry != nullptr);
StoreInstanceFieldInstr* store1 = nullptr;
StoreInstanceFieldInstr* store2 = nullptr;
ILMatcher cursor(flow_graph, entry);
RELEASE_ASSERT(cursor.TryMatch({
kMoveGlob,
kMatchAndMoveGoto,
kMoveGlob,
kMatchAndMoveBranchTrue,
kMoveGlob,
{kMatchAndMoveStoreInstanceField, &store1},
kMoveGlob,
{kMatchAndMoveStoreInstanceField, &store2},
}));
EXPECT(store1->ShouldEmitStoreBarrier() == false);
EXPECT(store2->ShouldEmitStoreBarrier() == true);
}
ISOLATE_UNIT_TEST_CASE(IRTest_WriteBarrierElimination_AtLeastOnce) {
DEBUG_ONLY(
SetFlagScope<bool> sfs(&FLAG_trace_write_barrier_elimination, true));
// Ensure that we process every block at least once during the analysis
// phase so that the out-sets will be initialized. If we don't process
// each block at least once, the store "c.next = n" will be marked
// NoWriteBarrier.
// clang-format off
auto kScript = Utils::CStringUniquePtr(OS::SCreate(nullptr,
R"(
class C {
%s C next;
}
@pragma("vm:never-inline")
fn() {}
foo(int x) {
C c = C();
C n = C();
if (x > 5) {
fn();
}
c.next = n;
return c;
}
main() { foo(0); foo(10); }
)", TestCase::LateTag()), std::free);
// clang-format on
const auto& root_library = Library::Handle(LoadTestScript(kScript.get()));
Invoke(root_library, "main");
const auto& function = Function::Handle(GetFunction(root_library, "foo"));
TestPipeline pipeline(function, CompilerPass::kJIT);
FlowGraph* flow_graph = pipeline.RunPasses({});
auto entry = flow_graph->graph_entry()->normal_entry();
EXPECT(entry != nullptr);
StoreInstanceFieldInstr* store = nullptr;
ILMatcher cursor(flow_graph, entry);
RELEASE_ASSERT(cursor.TryMatch({
kMoveGlob,
kMatchAndMoveBranchFalse,
kMoveGlob,
kMatchAndMoveGoto,
kMoveGlob,
{kMatchAndMoveStoreInstanceField, &store},
}));
EXPECT(store->ShouldEmitStoreBarrier() == true);
}
ISOLATE_UNIT_TEST_CASE(IRTest_WriteBarrierElimination_Arrays) {
DEBUG_ONLY(
SetFlagScope<bool> sfs(&FLAG_trace_write_barrier_elimination, true));
const char* nullable_tag = TestCase::NullableTag();
// Test that array allocations are not considered usable after a
// may-trigger-GC instruction (in this case CheckStackOverflow), unlike
// normal allocations, which are only interruped by a Dart call.
// clang-format off
auto kScript =
Utils::CStringUniquePtr(OS::SCreate(nullptr, R"(
class C {
%s C next;
}
@pragma("vm:never-inline")
fn() {}
foo(int x) {
C c = C();
C n = C();
List<C%s> array = List<C%s>.filled(1, null);
while (x --> 0) {
c.next = n;
n = c;
c = C();
}
array[0] = c;
return array;
}
main() { foo(10); }
)", TestCase::LateTag(), nullable_tag, nullable_tag), std::free);
// clang-format on
const auto& root_library = Library::Handle(LoadTestScript(kScript.get()));
Invoke(root_library, "main");
const auto& function = Function::Handle(GetFunction(root_library, "foo"));
TestPipeline pipeline(function, CompilerPass::kJIT);
FlowGraph* flow_graph = pipeline.RunPasses({});
auto entry = flow_graph->graph_entry()->normal_entry();
EXPECT(entry != nullptr);
StoreInstanceFieldInstr* store_into_c = nullptr;
StoreIndexedInstr* store_into_array = nullptr;
ILMatcher cursor(flow_graph, entry);
RELEASE_ASSERT(cursor.TryMatch({
kMoveGlob,
kMatchAndMoveGoto,
kMoveGlob,
kMatchAndMoveBranchTrue,
kMoveGlob,
{kMatchAndMoveStoreInstanceField, &store_into_c},
kMoveGlob,
kMatchAndMoveGoto,
kMoveGlob,
kMatchAndMoveBranchFalse,
kMoveGlob,
{kMatchAndMoveStoreIndexed, &store_into_array},
}));
EXPECT(store_into_c->ShouldEmitStoreBarrier() == false);
EXPECT(store_into_array->ShouldEmitStoreBarrier() == true);
}
ISOLATE_UNIT_TEST_CASE(IRTest_WriteBarrierElimination_Regress43786) {
DEBUG_ONLY(
SetFlagScope<bool> sfs(&FLAG_trace_write_barrier_elimination, true));
const char* kScript = R"(
foo() {
final root = List<dynamic>.filled(128, null);
List<dynamic> last = root;
for (int i = 0; i < 10 * 1024; ++i) {
final nc = List<dynamic>.filled(128, null);
last[0] = nc;
last = nc;
}
}
main() { foo(); }
)";
const auto& root_library = Library::Handle(LoadTestScript(kScript));
Invoke(root_library, "main");
const auto& function = Function::Handle(GetFunction(root_library, "foo"));
TestPipeline pipeline(function, CompilerPass::kJIT);
FlowGraph* flow_graph = pipeline.RunPasses({});
auto entry = flow_graph->graph_entry()->normal_entry();
EXPECT(entry != nullptr);
StoreIndexedInstr* store_into_phi = nullptr;
ILMatcher cursor(flow_graph, entry);
RELEASE_ASSERT(cursor.TryMatch(
{
kMatchAndMoveCreateArray,
kMatchAndMoveGoto,
kMatchAndMoveBranchTrue,
kMatchAndMoveCreateArray,
{kMatchAndMoveStoreIndexed, &store_into_phi},
},
kMoveGlob));
EXPECT(store_into_phi->array()->definition()->IsPhi());
EXPECT(store_into_phi->ShouldEmitStoreBarrier());
}
} // namespace dart