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// Copyright 2012 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/runtime-profiler.h"
#include "src/assembler.h"
#include "src/base/platform/platform.h"
#include "src/bootstrapper.h"
#include "src/code-stubs.h"
#include "src/compilation-cache.h"
#include "src/compiler.h"
#include "src/execution.h"
#include "src/frames-inl.h"
#include "src/full-codegen/full-codegen.h"
#include "src/global-handles.h"
#include "src/interpreter/interpreter.h"
namespace v8 {
namespace internal {
// Number of times a function has to be seen on the stack before it is
// compiled for baseline.
static const int kProfilerTicksBeforeBaseline = 1;
// Number of times a function has to be seen on the stack before it is
// optimized.
static const int kProfilerTicksBeforeOptimization = 2;
// Number of times a interpreted function has to be seen on the stack before
// it is optimized (with Turbofan, ignition is only optimized with Turbofan).
static const int kProfilerTicksBeforeOptimizingInterpretedFunction = 4;
// If the function optimization was disabled due to high deoptimization count,
// but the function is hot and has been seen on the stack this number of times,
// then we try to reenable optimization for this function.
static const int kProfilerTicksBeforeReenablingOptimization = 250;
// If a function does not have enough type info (according to
// FLAG_type_info_threshold), but has seen a huge number of ticks,
// optimize it as it is.
static const int kTicksWhenNotEnoughTypeInfo = 100;
// We only have one byte to store the number of ticks.
STATIC_ASSERT(kProfilerTicksBeforeOptimization < 256);
STATIC_ASSERT(kProfilerTicksBeforeOptimizingInterpretedFunction < 256);
STATIC_ASSERT(kProfilerTicksBeforeReenablingOptimization < 256);
STATIC_ASSERT(kTicksWhenNotEnoughTypeInfo < 256);
// Maximum size in bytes of generate code for a function to allow OSR.
static const int kOSRCodeSizeAllowanceBase =
100 * FullCodeGenerator::kCodeSizeMultiplier;
static const int kOSRCodeSizeAllowanceBaseIgnition =
10 * interpreter::Interpreter::kCodeSizeMultiplier;
static const int kOSRCodeSizeAllowancePerTick =
4 * FullCodeGenerator::kCodeSizeMultiplier;
static const int kOSRCodeSizeAllowancePerTickIgnition =
2 * interpreter::Interpreter::kCodeSizeMultiplier;
// Maximum size in bytes of generated code for a function to be optimized
// the very first time it is seen on the stack.
static const int kMaxSizeEarlyOpt =
5 * FullCodeGenerator::kCodeSizeMultiplier;
static const int kMaxSizeEarlyOptIgnition =
5 * interpreter::Interpreter::kCodeSizeMultiplier;
#define OPTIMIZATION_REASON_LIST(V) \
V(DoNotOptimize, "do not optimize") \
V(HotAndStable, "hot and stable") \
V(HotEnoughForBaseline, "hot enough for baseline") \
V(HotWithoutMuchTypeInfo, "not much type info but very hot") \
V(SmallFunction, "small function")
enum class OptimizationReason : uint8_t {
#define OPTIMIZATION_REASON_CONSTANTS(Constant, message) k##Constant,
OPTIMIZATION_REASON_LIST(OPTIMIZATION_REASON_CONSTANTS)
#undef OPTIMIZATION_REASON_CONSTANTS
};
char const* OptimizationReasonToString(OptimizationReason reason) {
static char const* reasons[] = {
#define OPTIMIZATION_REASON_TEXTS(Constant, message) message,
OPTIMIZATION_REASON_LIST(OPTIMIZATION_REASON_TEXTS)
#undef OPTIMIZATION_REASON_TEXTS
};
size_t const index = static_cast<size_t>(reason);
DCHECK_LT(index, arraysize(reasons));
return reasons[index];
}
std::ostream& operator<<(std::ostream& os, OptimizationReason reason) {
return os << OptimizationReasonToString(reason);
}
RuntimeProfiler::RuntimeProfiler(Isolate* isolate)
: isolate_(isolate),
any_ic_changed_(false) {
}
static void GetICCounts(JSFunction* function, int* ic_with_type_info_count,
int* ic_generic_count, int* ic_total_count,
int* type_info_percentage, int* generic_percentage) {
*ic_total_count = 0;
*ic_generic_count = 0;
*ic_with_type_info_count = 0;
if (function->code()->kind() == Code::FUNCTION) {
Code* shared_code = function->shared()->code();
Object* raw_info = shared_code->type_feedback_info();
if (raw_info->IsTypeFeedbackInfo()) {
TypeFeedbackInfo* info = TypeFeedbackInfo::cast(raw_info);
*ic_with_type_info_count = info->ic_with_type_info_count();
*ic_generic_count = info->ic_generic_count();
*ic_total_count = info->ic_total_count();
}
}
// Harvest vector-ics as well
TypeFeedbackVector* vector = function->feedback_vector();
int with = 0, gen = 0, type_vector_ic_count = 0;
const bool is_interpreted =
function->shared()->code()->is_interpreter_trampoline_builtin();
vector->ComputeCounts(&with, &gen, &type_vector_ic_count, is_interpreted);
*ic_total_count += type_vector_ic_count;
*ic_with_type_info_count += with;
*ic_generic_count += gen;
if (*ic_total_count > 0) {
*type_info_percentage = 100 * *ic_with_type_info_count / *ic_total_count;
*generic_percentage = 100 * *ic_generic_count / *ic_total_count;
} else {
*type_info_percentage = 100; // Compared against lower bound.
*generic_percentage = 0; // Compared against upper bound.
}
}
static void TraceRecompile(JSFunction* function, const char* reason,
const char* type) {
if (FLAG_trace_opt &&
function->shared()->PassesFilter(FLAG_hydrogen_filter)) {
PrintF("[marking ");
function->ShortPrint();
PrintF(" for %s recompilation, reason: %s", type, reason);
if (FLAG_type_info_threshold > 0) {
int typeinfo, generic, total, type_percentage, generic_percentage;
GetICCounts(function, &typeinfo, &generic, &total, &type_percentage,
&generic_percentage);
PrintF(", ICs with typeinfo: %d/%d (%d%%)", typeinfo, total,
type_percentage);
PrintF(", generic ICs: %d/%d (%d%%)", generic, total, generic_percentage);
}
PrintF("]\n");
}
}
void RuntimeProfiler::Optimize(JSFunction* function,
OptimizationReason reason) {
DCHECK_NE(reason, OptimizationReason::kDoNotOptimize);
TraceRecompile(function, OptimizationReasonToString(reason), "optimized");
function->AttemptConcurrentOptimization();
}
void RuntimeProfiler::Baseline(JSFunction* function,
OptimizationReason reason) {
DCHECK_NE(reason, OptimizationReason::kDoNotOptimize);
TraceRecompile(function, OptimizationReasonToString(reason), "baseline");
// TODO(4280): Fix this to check function is compiled for the interpreter
// once we have a standard way to check that. For now function will only
// have a bytecode array if compiled for the interpreter.
DCHECK(function->shared()->HasBytecodeArray());
function->MarkForBaseline();
}
void RuntimeProfiler::AttemptOnStackReplacement(JavaScriptFrame* frame,
int loop_nesting_levels) {
JSFunction* function = frame->function();
SharedFunctionInfo* shared = function->shared();
if (!FLAG_use_osr || function->shared()->IsBuiltin()) {
return;
}
// If the code is not optimizable, don't try OSR.
if (shared->optimization_disabled()) return;
// We are not prepared to do OSR for a function that already has an
// allocated arguments object. The optimized code would bypass it for
// arguments accesses, which is unsound. Don't try OSR.
if (shared->uses_arguments()) return;
// We're using on-stack replacement: modify unoptimized code so that
// certain back edges in any unoptimized frame will trigger on-stack
// replacement for that frame.
// - Ignition: Store new loop nesting level in BytecodeArray header.
// - FullCodegen: Patch back edges up to new level using BackEdgeTable.
if (FLAG_trace_osr) {
PrintF("[OSR - arming back edges in ");
function->PrintName();
PrintF("]\n");
}
if (frame->type() == StackFrame::JAVA_SCRIPT) {
DCHECK(shared->HasBaselineCode());
DCHECK(BackEdgeTable::Verify(shared->GetIsolate(), shared->code()));
for (int i = 0; i < loop_nesting_levels; i++) {
BackEdgeTable::Patch(isolate_, shared->code());
}
} else if (frame->type() == StackFrame::INTERPRETED) {
DCHECK(shared->HasBytecodeArray());
if (!FLAG_ignition_osr) return; // Only use this when enabled.
int level = shared->bytecode_array()->osr_loop_nesting_level();
shared->bytecode_array()->set_osr_loop_nesting_level(
Min(level + loop_nesting_levels, AbstractCode::kMaxLoopNestingMarker));
} else {
UNREACHABLE();
}
}
void RuntimeProfiler::MaybeOptimizeFullCodegen(JSFunction* function,
JavaScriptFrame* frame,
int frame_count) {
SharedFunctionInfo* shared = function->shared();
Code* shared_code = shared->code();
if (shared_code->kind() != Code::FUNCTION) return;
if (function->IsInOptimizationQueue()) return;
if (FLAG_always_osr) {
AttemptOnStackReplacement(frame, AbstractCode::kMaxLoopNestingMarker);
// Fall through and do a normal optimized compile as well.
} else if (!frame->is_optimized() &&
(function->IsMarkedForOptimization() ||
function->IsMarkedForConcurrentOptimization() ||
function->IsOptimized())) {
// Attempt OSR if we are still running unoptimized code even though the
// the function has long been marked or even already been optimized.
int ticks = shared_code->profiler_ticks();
int64_t allowance =
kOSRCodeSizeAllowanceBase +
static_cast<int64_t>(ticks) * kOSRCodeSizeAllowancePerTick;
if (shared_code->CodeSize() > allowance &&
ticks < Code::ProfilerTicksField::kMax) {
shared_code->set_profiler_ticks(ticks + 1);
} else {
AttemptOnStackReplacement(frame);
}
return;
}
// Only record top-level code on top of the execution stack and
// avoid optimizing excessively large scripts since top-level code
// will be executed only once.
const int kMaxToplevelSourceSize = 10 * 1024;
if (shared->is_toplevel() &&
(frame_count > 1 || shared->SourceSize() > kMaxToplevelSourceSize)) {
return;
}
// Do not record non-optimizable functions.
if (shared->optimization_disabled()) {
if (shared->deopt_count() >= FLAG_max_opt_count) {
// If optimization was disabled due to many deoptimizations,
// then check if the function is hot and try to reenable optimization.
int ticks = shared_code->profiler_ticks();
if (ticks >= kProfilerTicksBeforeReenablingOptimization) {
shared_code->set_profiler_ticks(0);
shared->TryReenableOptimization();
} else {
shared_code->set_profiler_ticks(ticks + 1);
}
}
return;
}
if (function->IsOptimized()) return;
int ticks = shared_code->profiler_ticks();
if (ticks >= kProfilerTicksBeforeOptimization) {
int typeinfo, generic, total, type_percentage, generic_percentage;
GetICCounts(function, &typeinfo, &generic, &total, &type_percentage,
&generic_percentage);
if (type_percentage >= FLAG_type_info_threshold &&
generic_percentage <= FLAG_generic_ic_threshold) {
// If this particular function hasn't had any ICs patched for enough
// ticks, optimize it now.
Optimize(function, OptimizationReason::kHotAndStable);
} else if (ticks >= kTicksWhenNotEnoughTypeInfo) {
Optimize(function, OptimizationReason::kHotWithoutMuchTypeInfo);
} else {
shared_code->set_profiler_ticks(ticks + 1);
if (FLAG_trace_opt_verbose) {
PrintF("[not yet optimizing ");
function->PrintName();
PrintF(", not enough type info: %d/%d (%d%%)]\n", typeinfo, total,
type_percentage);
}
}
} else if (!any_ic_changed_ &&
shared_code->instruction_size() < kMaxSizeEarlyOpt) {
// If no IC was patched since the last tick and this function is very
// small, optimistically optimize it now.
int typeinfo, generic, total, type_percentage, generic_percentage;
GetICCounts(function, &typeinfo, &generic, &total, &type_percentage,
&generic_percentage);
if (type_percentage >= FLAG_type_info_threshold &&
generic_percentage <= FLAG_generic_ic_threshold) {
Optimize(function, OptimizationReason::kSmallFunction);
} else {
shared_code->set_profiler_ticks(ticks + 1);
}
} else {
shared_code->set_profiler_ticks(ticks + 1);
}
}
void RuntimeProfiler::MaybeBaselineIgnition(JSFunction* function,
JavaScriptFrame* frame) {
if (function->IsInOptimizationQueue()) return;
if (FLAG_always_osr) {
AttemptOnStackReplacement(frame, AbstractCode::kMaxLoopNestingMarker);
// Fall through and do a normal baseline compile as well.
} else if (MaybeOSRIgnition(function, frame)) {
return;
}
SharedFunctionInfo* shared = function->shared();
int ticks = shared->profiler_ticks();
if (shared->optimization_disabled() &&
shared->disable_optimization_reason() == kOptimizationDisabledForTest) {
// Don't baseline functions which have been marked by NeverOptimizeFunction
// in a test.
return;
}
if (ticks >= kProfilerTicksBeforeBaseline) {
Baseline(function, OptimizationReason::kHotEnoughForBaseline);
}
}
void RuntimeProfiler::MaybeOptimizeIgnition(JSFunction* function,
JavaScriptFrame* frame) {
if (function->IsInOptimizationQueue()) return;
if (FLAG_always_osr) {
AttemptOnStackReplacement(frame, AbstractCode::kMaxLoopNestingMarker);
// Fall through and do a normal optimized compile as well.
} else if (MaybeOSRIgnition(function, frame)) {
return;
}
SharedFunctionInfo* shared = function->shared();
int ticks = shared->profiler_ticks();
if (shared->optimization_disabled()) {
if (shared->deopt_count() >= FLAG_max_opt_count) {
// If optimization was disabled due to many deoptimizations,
// then check if the function is hot and try to reenable optimization.
if (ticks >= kProfilerTicksBeforeReenablingOptimization) {
shared->set_profiler_ticks(0);
shared->TryReenableOptimization();
}
}
return;
}
if (function->IsOptimized()) return;
OptimizationReason reason = ShouldOptimizeIgnition(function, frame);
if (reason != OptimizationReason::kDoNotOptimize) {
Optimize(function, reason);
}
}
bool RuntimeProfiler::MaybeOSRIgnition(JSFunction* function,
JavaScriptFrame* frame) {
if (!FLAG_ignition_osr) return false;
SharedFunctionInfo* shared = function->shared();
int ticks = shared->profiler_ticks();
// TODO(rmcilroy): Also ensure we only OSR top-level code if it is smaller
// than kMaxToplevelSourceSize.
bool osr_before_baselined = function->IsMarkedForBaseline() &&
ShouldOptimizeIgnition(function, frame) !=
OptimizationReason::kDoNotOptimize;
if (!frame->is_optimized() &&
(osr_before_baselined || function->IsMarkedForOptimization() ||
function->IsMarkedForConcurrentOptimization() ||
function->IsOptimized())) {
// Attempt OSR if we are still running interpreted code even though the
// the function has long been marked or even already been optimized.
int64_t allowance =
kOSRCodeSizeAllowanceBaseIgnition +
static_cast<int64_t>(ticks) * kOSRCodeSizeAllowancePerTickIgnition;
if (shared->bytecode_array()->Size() <= allowance) {
AttemptOnStackReplacement(frame);
}
return true;
}
return false;
}
OptimizationReason RuntimeProfiler::ShouldOptimizeIgnition(
JSFunction* function, JavaScriptFrame* frame) {
SharedFunctionInfo* shared = function->shared();
int ticks = shared->profiler_ticks();
if (ticks >= kProfilerTicksBeforeOptimizingInterpretedFunction) {
int typeinfo, generic, total, type_percentage, generic_percentage;
GetICCounts(function, &typeinfo, &generic, &total, &type_percentage,
&generic_percentage);
if (type_percentage >= FLAG_type_info_threshold &&
generic_percentage <= FLAG_generic_ic_threshold) {
// If this particular function hasn't had any ICs patched for enough
// ticks, optimize it now.
return OptimizationReason::kHotAndStable;
} else if (ticks >= kTicksWhenNotEnoughTypeInfo) {
return OptimizationReason::kHotWithoutMuchTypeInfo;
} else {
if (FLAG_trace_opt_verbose) {
PrintF("[not yet optimizing ");
function->PrintName();
PrintF(", not enough type info: %d/%d (%d%%)]\n", typeinfo, total,
type_percentage);
}
return OptimizationReason::kDoNotOptimize;
}
} else if (!any_ic_changed_ &&
shared->bytecode_array()->Size() < kMaxSizeEarlyOptIgnition) {
// If no IC was patched since the last tick and this function is very
// small, optimistically optimize it now.
int typeinfo, generic, total, type_percentage, generic_percentage;
GetICCounts(function, &typeinfo, &generic, &total, &type_percentage,
&generic_percentage);
if (type_percentage >= FLAG_type_info_threshold &&
generic_percentage <= FLAG_generic_ic_threshold) {
return OptimizationReason::kSmallFunction;
}
}
return OptimizationReason::kDoNotOptimize;
}
void RuntimeProfiler::MarkCandidatesForOptimization() {
HandleScope scope(isolate_);
if (!isolate_->use_crankshaft()) return;
DisallowHeapAllocation no_gc;
// Run through the JavaScript frames and collect them. If we already
// have a sample of the function, we mark it for optimizations
// (eagerly or lazily).
int frame_count = 0;
int frame_count_limit = FLAG_frame_count;
for (JavaScriptFrameIterator it(isolate_);
frame_count++ < frame_count_limit && !it.done();
it.Advance()) {
JavaScriptFrame* frame = it.frame();
JSFunction* function = frame->function();
List<JSFunction*> functions(4);
frame->GetFunctions(&functions);
for (int i = functions.length(); --i >= 0; ) {
SharedFunctionInfo* shared_function_info = functions[i]->shared();
int ticks = shared_function_info->profiler_ticks();
if (ticks < Smi::kMaxValue) {
shared_function_info->set_profiler_ticks(ticks + 1);
}
}
Compiler::CompilationTier next_tier =
Compiler::NextCompilationTier(function);
if (function->shared()->code()->is_interpreter_trampoline_builtin()) {
if (next_tier == Compiler::BASELINE) {
MaybeBaselineIgnition(function, frame);
} else {
DCHECK_EQ(next_tier, Compiler::OPTIMIZED);
MaybeOptimizeIgnition(function, frame);
}
} else {
DCHECK_EQ(next_tier, Compiler::OPTIMIZED);
MaybeOptimizeFullCodegen(function, frame, frame_count);
}
}
any_ic_changed_ = false;
}
} // namespace internal
} // namespace v8