v8/test/unittests/test-helpers.cc
Ross McIlroy f92d7196b9 [SFI] Always store function_literal_id in SFI.
Calling FindIndexInScript performs a linear search on the script functions and can
take considerable time. With Bytecode flushing we will lose the function_literal_id
and have to call FindIndexInScript if we ever recompile the flushed function. This
can take a significant proportion of the recompilation time and has caused regressions
in rendering times for some web applications (e.g, 395ms in FindIndexInScript for 132ms
spent lazily re-compiling code).

To avoid this, add function_literal_id back into the SFI and remove it from
UnoptimizedCompileInfo. This will slightly regress memory usage (particularly
in cases where many of the SFIs are compiled), however it means we can remove
the FindIndexInScript function and avoid these long-tail regressions when
bytecode is flushed.

BUG=chromium:965833

Change-Id: Ia31e82eb6c871a6d698a518326a8555822a7a1d8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1669700
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62319}
2019-06-21 16:23:27 +00:00

77 lines
2.8 KiB
C++

// Copyright 2016 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 "test/unittests/test-helpers.h"
#include "include/v8.h"
#include "src/api/api.h"
#include "src/base/template-utils.h"
#include "src/execution/isolate.h"
#include "src/handles/handles.h"
#include "src/objects/objects-inl.h"
#include "src/objects/objects.h"
#include "src/parsing/scanner-character-streams.h"
#include "src/parsing/scanner.h"
namespace v8 {
namespace internal {
namespace test {
Handle<String> CreateSource(Isolate* isolate,
ExternalOneByteString::Resource* maybe_resource) {
if (!maybe_resource) {
static const char test_script[] = "(x) { x*x; }";
maybe_resource = new test::ScriptResource(test_script, strlen(test_script));
}
return isolate->factory()
->NewExternalStringFromOneByte(maybe_resource)
.ToHandleChecked();
}
Handle<SharedFunctionInfo> CreateSharedFunctionInfo(
Isolate* isolate,
v8::String::ExternalOneByteStringResource* maybe_resource) {
HandleScope scope(isolate);
Handle<String> source = CreateSource(isolate, maybe_resource);
Handle<Script> script = isolate->factory()->NewScript(source);
Handle<WeakFixedArray> infos = isolate->factory()->NewWeakFixedArray(3);
script->set_shared_function_infos(*infos);
Handle<SharedFunctionInfo> shared =
isolate->factory()->NewSharedFunctionInfoForBuiltin(
isolate->factory()->NewStringFromAsciiChecked("f"),
Builtins::kCompileLazy);
int function_literal_id = 1;
shared->set_function_literal_id(function_literal_id);
// Ensure that the function can be compiled lazily.
shared->set_uncompiled_data(
*isolate->factory()->NewUncompiledDataWithoutPreparseData(
ReadOnlyRoots(isolate).empty_string_handle(), 0, source->length()));
// Make sure we have an outer scope info, even though it's empty
shared->set_raw_outer_scope_info_or_feedback_metadata(
ScopeInfo::Empty(isolate));
SharedFunctionInfo::SetScript(shared, script, function_literal_id);
return scope.CloseAndEscape(shared);
}
std::unique_ptr<ParseInfo> OuterParseInfoForShared(
Isolate* isolate, Handle<SharedFunctionInfo> shared) {
Handle<Script> script =
Handle<Script>::cast(handle(shared->script(), isolate));
std::unique_ptr<ParseInfo> result =
base::make_unique<ParseInfo>(isolate, script);
// Create a character stream to simulate the parser having done so for the
// to-level ParseProgram.
Handle<String> source(String::cast(script->source()), isolate);
std::unique_ptr<Utf16CharacterStream> stream(
ScannerStream::For(isolate, source));
result->set_character_stream(std::move(stream));
return result;
}
} // namespace test
} // namespace internal
} // namespace v8