| // 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/v8.h" |
| |
| #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/execution.h" |
| #include "src/full-codegen.h" |
| #include "src/global-handles.h" |
| #include "src/heap/mark-compact.h" |
| #include "src/isolate-inl.h" |
| #include "src/scopeinfo.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| // Number of times a function has to be seen on the stack before it is |
| // optimized. |
| static const int kProfilerTicksBeforeOptimization = 2; |
| // 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(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 kOSRCodeSizeAllowancePerTick = |
| 4 * FullCodeGenerator::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; |
| |
| |
| RuntimeProfiler::RuntimeProfiler(Isolate* isolate) |
| : isolate_(isolate), |
| any_ic_changed_(false) { |
| } |
| |
| |
| static void GetICCounts(SharedFunctionInfo* shared, |
| int* ic_with_type_info_count, int* ic_generic_count, |
| int* ic_total_count, int* type_info_percentage, |
| int* generic_percentage) { |
| Code* shared_code = shared->code(); |
| *ic_total_count = 0; |
| *ic_generic_count = 0; |
| *ic_with_type_info_count = 0; |
| 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 = shared->feedback_vector(); |
| *ic_with_type_info_count += vector->ic_with_type_info_count(); |
| *ic_generic_count += vector->ic_generic_count(); |
| |
| 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. |
| } |
| } |
| |
| |
| void RuntimeProfiler::Optimize(JSFunction* function, const char* reason) { |
| DCHECK(function->IsOptimizable()); |
| |
| if (FLAG_trace_opt && function->PassesFilter(FLAG_hydrogen_filter)) { |
| PrintF("[marking "); |
| function->ShortPrint(); |
| PrintF(" for recompilation, reason: %s", reason); |
| if (FLAG_type_info_threshold > 0) { |
| int typeinfo, generic, total, type_percentage, generic_percentage; |
| GetICCounts(function->shared(), &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"); |
| } |
| |
| |
| if (isolate_->concurrent_recompilation_enabled() && |
| !isolate_->bootstrapper()->IsActive()) { |
| if (isolate_->concurrent_osr_enabled() && |
| isolate_->optimizing_compiler_thread()->IsQueuedForOSR(function)) { |
| // Do not attempt regular recompilation if we already queued this for OSR. |
| // TODO(yangguo): This is necessary so that we don't install optimized |
| // code on a function that is already optimized, since OSR and regular |
| // recompilation race. This goes away as soon as OSR becomes one-shot. |
| return; |
| } |
| DCHECK(!function->IsInOptimizationQueue()); |
| function->MarkForConcurrentOptimization(); |
| } else { |
| // The next call to the function will trigger optimization. |
| function->MarkForOptimization(); |
| } |
| } |
| |
| |
| void RuntimeProfiler::AttemptOnStackReplacement(JSFunction* function, |
| int loop_nesting_levels) { |
| SharedFunctionInfo* shared = function->shared(); |
| // See AlwaysFullCompiler (in compiler.cc) comment on why we need |
| // Debug::has_break_points(). |
| if (!FLAG_use_osr || |
| isolate_->DebuggerHasBreakPoints() || |
| function->IsBuiltin()) { |
| return; |
| } |
| |
| // If the code is not optimizable, don't try OSR. |
| if (!shared->code()->optimizable()) 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: patch the unoptimized code so that |
| // any back edge in any unoptimized frame will trigger on-stack |
| // replacement for that frame. |
| if (FLAG_trace_osr) { |
| PrintF("[OSR - patching back edges in "); |
| function->PrintName(); |
| PrintF("]\n"); |
| } |
| |
| for (int i = 0; i < loop_nesting_levels; i++) { |
| BackEdgeTable::Patch(isolate_, shared->code()); |
| } |
| } |
| |
| |
| void RuntimeProfiler::OptimizeNow() { |
| HandleScope scope(isolate_); |
| |
| if (isolate_->DebuggerHasBreakPoints()) 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(); |
| |
| SharedFunctionInfo* shared = function->shared(); |
| Code* shared_code = shared->code(); |
| |
| 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); |
| } |
| } |
| |
| if (shared_code->kind() != Code::FUNCTION) continue; |
| if (function->IsInOptimizationQueue()) continue; |
| |
| if (FLAG_always_osr) { |
| AttemptOnStackReplacement(function, Code::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(); |
| int allowance = kOSRCodeSizeAllowanceBase + |
| ticks * kOSRCodeSizeAllowancePerTick; |
| if (shared_code->CodeSize() > allowance) { |
| if (ticks < 255) shared_code->set_profiler_ticks(ticks + 1); |
| } else { |
| AttemptOnStackReplacement(function); |
| } |
| continue; |
| } |
| |
| // 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)) { |
| continue; |
| } |
| |
| // 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); |
| } |
| } |
| continue; |
| } |
| if (!function->IsOptimizable()) continue; |
| |
| int ticks = shared_code->profiler_ticks(); |
| |
| if (ticks >= kProfilerTicksBeforeOptimization) { |
| int typeinfo, generic, total, type_percentage, generic_percentage; |
| GetICCounts(shared, &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, "hot and stable"); |
| } else if (ticks >= kTicksWhenNotEnoughTypeInfo) { |
| Optimize(function, "not much type info but very hot"); |
| } 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(shared, &typeinfo, &generic, &total, &type_percentage, |
| &generic_percentage); |
| if (type_percentage >= FLAG_type_info_threshold && |
| generic_percentage <= FLAG_generic_ic_threshold) { |
| Optimize(function, "small function"); |
| } else { |
| shared_code->set_profiler_ticks(ticks + 1); |
| } |
| } else { |
| shared_code->set_profiler_ticks(ticks + 1); |
| } |
| } |
| any_ic_changed_ = false; |
| } |
| |
| |
| } } // namespace v8::internal |