Merge V8 at 3.9.24.13

Bug: 5688872
Change-Id: Id0aa8d23375030494d3189c31774059c0f5398fc

1 files changed, 174 insertions, 52 deletions

diff --git a/src/runtime-profiler.cc b/src/runtime-profiler.cc
index 26d88461..6ed4ff48 100644
--- a/src/runtime-profiler.cc
+++ b/src/runtime-profiler.cc
@@ -1,4 +1,4 @@
-// Copyright 2011 the V8 project authors. All rights reserved.
+// Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
@@ -35,6 +35,7 @@
 #include "deoptimizer.h"
 #include "execution.h"
 #include "global-handles.h"
+#include "isolate-inl.h"
 #include "mark-compact.h"
 #include "platform.h"
 #include "scopeinfo.h"
@@ -45,6 +46,8 @@ namespace internal {
 
 // Optimization sampler constants.
 static const int kSamplerFrameCount = 2;
+
+// Constants for statistical profiler.
 static const int kSamplerFrameWeight[kSamplerFrameCount] = { 2, 1 };
 
 static const int kSamplerTicksBetweenThresholdAdjustment = 32;
@@ -57,14 +60,24 @@ static const int kSamplerThresholdSizeFactorInit = 3;
 
 static const int kSizeLimit = 1500;
 
+// Constants for counter based profiler.
+
+// Number of times a function has to be seen on the stack before it is
+// optimized.
+static const int kProfilerTicksBeforeOptimization = 2;
+
+// 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 = 500;
+
 
 Atomic32 RuntimeProfiler::state_ = 0;
-// TODO(isolates): Create the semaphore lazily and clean it up when no
-// longer required.
-Semaphore* RuntimeProfiler::semaphore_ = OS::CreateSemaphore(0);
+
+// TODO(isolates): Clean up the semaphore when it is no longer required.
+static LazySemaphore<0>::type semaphore = LAZY_SEMAPHORE_INITIALIZER;
 
 #ifdef DEBUG
-bool RuntimeProfiler::has_been_globally_setup_ = false;
+bool RuntimeProfiler::has_been_globally_set_up_ = false;
 #endif
 bool RuntimeProfiler::enabled_ = false;
 
@@ -81,21 +94,45 @@ RuntimeProfiler::RuntimeProfiler(Isolate* isolate)
 
 
 void RuntimeProfiler::GlobalSetup() {
-  ASSERT(!has_been_globally_setup_);
+  ASSERT(!has_been_globally_set_up_);
   enabled_ = V8::UseCrankshaft() && FLAG_opt;
 #ifdef DEBUG
-  has_been_globally_setup_ = true;
+  has_been_globally_set_up_ = true;
 #endif
 }
 
 
-void RuntimeProfiler::Optimize(JSFunction* function) {
+static void GetICCounts(JSFunction* function,
+                        int* ic_with_typeinfo_count,
+                        int* ic_total_count,
+                        int* percentage) {
+  *ic_total_count = 0;
+  *ic_with_typeinfo_count = 0;
+  Object* raw_info =
+      function->shared()->code()->type_feedback_info();
+  if (raw_info->IsTypeFeedbackInfo()) {
+    TypeFeedbackInfo* info = TypeFeedbackInfo::cast(raw_info);
+    *ic_with_typeinfo_count = info->ic_with_typeinfo_count();
+    *ic_total_count = info->ic_total_count();
+  }
+  *percentage = *ic_total_count > 0
+      ? 100 * *ic_with_typeinfo_count / *ic_total_count
+      : 100;
+}
+
+
+void RuntimeProfiler::Optimize(JSFunction* function, const char* reason) {
   ASSERT(function->IsOptimizable());
   if (FLAG_trace_opt) {
     PrintF("[marking ");
     function->PrintName();
     PrintF(" 0x%" V8PRIxPTR, reinterpret_cast<intptr_t>(function->address()));
-    PrintF(" for recompilation");
+    PrintF(" for recompilation, reason: %s", reason);
+    if (FLAG_type_info_threshold > 0) {
+      int typeinfo, total, percentage;
+      GetICCounts(function, &typeinfo, &total, &percentage);
+      PrintF(", ICs with typeinfo: %d/%d (%d%%)", typeinfo, total, percentage);
+    }
     PrintF("]\n");
   }
 
@@ -134,15 +171,26 @@ void RuntimeProfiler::AttemptOnStackReplacement(JSFunction* function) {
 
   // Get the stack check stub code object to match against.  We aren't
   // prepared to generate it, but we don't expect to have to.
-  StackCheckStub check_stub;
-  Object* check_code;
-  MaybeObject* maybe_check_code = check_stub.TryGetCode();
-  if (maybe_check_code->ToObject(&check_code)) {
+  bool found_code = false;
+  Code* stack_check_code = NULL;
+#if defined(V8_TARGET_ARCH_IA32) || \
+    defined(V8_TARGET_ARCH_ARM) || \
+    defined(V8_TARGET_ARCH_MIPS)
+  if (FLAG_count_based_interrupts) {
+    InterruptStub interrupt_stub;
+    found_code = interrupt_stub.FindCodeInCache(&stack_check_code);
+  } else  // NOLINT
+#endif
+  {  // NOLINT
+    StackCheckStub check_stub;
+    found_code = check_stub.FindCodeInCache(&stack_check_code);
+  }
+  if (found_code) {
     Code* replacement_code =
         isolate_->builtins()->builtin(Builtins::kOnStackReplacement);
     Code* unoptimized_code = shared->code();
     Deoptimizer::PatchStackCheckCode(unoptimized_code,
-                                     Code::cast(check_code),
+                                     stack_check_code,
                                      replacement_code);
   }
 }
@@ -186,28 +234,33 @@ void RuntimeProfiler::OptimizeNow() {
   JSFunction* samples[kSamplerFrameCount];
   int sample_count = 0;
   int frame_count = 0;
+  int frame_count_limit = FLAG_watch_ic_patching ? FLAG_frame_count
+                                                 : kSamplerFrameCount;
   for (JavaScriptFrameIterator it(isolate_);
-       frame_count++ < kSamplerFrameCount && !it.done();
+       frame_count++ < frame_count_limit && !it.done();
        it.Advance()) {
     JavaScriptFrame* frame = it.frame();
     JSFunction* function = JSFunction::cast(frame->function());
 
-    // Adjust threshold each time we have processed
-    // a certain number of ticks.
-    if (sampler_ticks_until_threshold_adjustment_ > 0) {
-      sampler_ticks_until_threshold_adjustment_--;
-      if (sampler_ticks_until_threshold_adjustment_ <= 0) {
-        // If the threshold is not already at the minimum
-        // modify and reset the ticks until next adjustment.
-        if (sampler_threshold_ > kSamplerThresholdMin) {
-          sampler_threshold_ -= kSamplerThresholdDelta;
-          sampler_ticks_until_threshold_adjustment_ =
-              kSamplerTicksBetweenThresholdAdjustment;
+    if (!FLAG_watch_ic_patching) {
+      // Adjust threshold each time we have processed
+      // a certain number of ticks.
+      if (sampler_ticks_until_threshold_adjustment_ > 0) {
+        sampler_ticks_until_threshold_adjustment_--;
+        if (sampler_ticks_until_threshold_adjustment_ <= 0) {
+          // If the threshold is not already at the minimum
+          // modify and reset the ticks until next adjustment.
+          if (sampler_threshold_ > kSamplerThresholdMin) {
+            sampler_threshold_ -= kSamplerThresholdDelta;
+            sampler_ticks_until_threshold_adjustment_ =
+                kSamplerTicksBetweenThresholdAdjustment;
+          }
         }
       }
     }
 
-    if (function->IsMarkedForLazyRecompilation()) {
+    if (function->IsMarkedForLazyRecompilation() &&
+        function->shared()->code()->kind() == Code::FUNCTION) {
       Code* unoptimized = function->shared()->code();
       int nesting = unoptimized->allow_osr_at_loop_nesting_level();
       if (nesting == 0) AttemptOnStackReplacement(function);
@@ -217,37 +270,101 @@ void RuntimeProfiler::OptimizeNow() {
 
     // Do not record non-optimizable functions.
     if (!function->IsOptimizable()) continue;
-    samples[sample_count++] = function;
+    if (function->shared()->optimization_disabled()) 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 (function->shared()->is_toplevel()
+        && (frame_count > 1
+            || function->shared()->SourceSize() > kMaxToplevelSourceSize)) {
+      continue;
+    }
+
+    if (FLAG_watch_ic_patching) {
+      int ticks = function->shared()->profiler_ticks();
+
+      if (ticks >= kProfilerTicksBeforeOptimization) {
+        int typeinfo, total, percentage;
+        GetICCounts(function, &typeinfo, &total, &percentage);
+        if (percentage >= FLAG_type_info_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 >= 100) {
+          // If this function does not have enough type info, but has
+          // seen a huge number of ticks, optimize it as it is.
+          Optimize(function, "not much type info but very hot");
+        } else {
+          function->shared()->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, percentage);
+          }
+        }
+      } else if (!any_ic_changed_ &&
+          function->shared()->code()->instruction_size() < kMaxSizeEarlyOpt) {
+        // If no IC was patched since the last tick and this function is very
+        // small, optimistically optimize it now.
+        Optimize(function, "small function");
+      } else if (!code_generated_ &&
+          !any_ic_changed_ &&
+          total_code_generated_ > 0 &&
+          total_code_generated_ < 2000) {
+        // If no code was generated and no IC was patched since the last tick,
+        // but a little code has already been generated since last Reset(),
+        // then type info might already be stable and we can optimize now.
+        Optimize(function, "stable on startup");
+      } else {
+        function->shared()->set_profiler_ticks(ticks + 1);
+      }
+    } else {  // !FLAG_watch_ic_patching
+      samples[sample_count++] = function;
 
-    int function_size = function->shared()->SourceSize();
-    int threshold_size_factor = (function_size > kSizeLimit)
-        ? sampler_threshold_size_factor_
-        : 1;
+      int function_size = function->shared()->SourceSize();
+      int threshold_size_factor = (function_size > kSizeLimit)
+          ? sampler_threshold_size_factor_
+          : 1;
 
-    int threshold = sampler_threshold_ * threshold_size_factor;
+      int threshold = sampler_threshold_ * threshold_size_factor;
 
-    if (LookupSample(function) >= threshold) {
-      Optimize(function);
+      if (LookupSample(function) >= threshold) {
+        Optimize(function, "sampler window lookup");
+      }
     }
   }
-
-  // Add the collected functions as samples. It's important not to do
-  // this as part of collecting them because this will interfere with
-  // the sample lookup in case of recursive functions.
-  for (int i = 0; i < sample_count; i++) {
-    AddSample(samples[i], kSamplerFrameWeight[i]);
+  if (FLAG_watch_ic_patching) {
+    any_ic_changed_ = false;
+    code_generated_ = false;
+  } else {  // !FLAG_watch_ic_patching
+    // Add the collected functions as samples. It's important not to do
+    // this as part of collecting them because this will interfere with
+    // the sample lookup in case of recursive functions.
+    for (int i = 0; i < sample_count; i++) {
+      AddSample(samples[i], kSamplerFrameWeight[i]);
+    }
   }
 }
 
 
 void RuntimeProfiler::NotifyTick() {
+#if defined(V8_TARGET_ARCH_IA32) || \
+    defined(V8_TARGET_ARCH_ARM) || \
+    defined(V8_TARGET_ARCH_MIPS)
+  if (FLAG_count_based_interrupts) return;
+#endif
   isolate_->stack_guard()->RequestRuntimeProfilerTick();
 }
 
 
-void RuntimeProfiler::Setup() {
-  ASSERT(has_been_globally_setup_);
-  ClearSampleBuffer();
+void RuntimeProfiler::SetUp() {
+  ASSERT(has_been_globally_set_up_);
+  if (!FLAG_watch_ic_patching) {
+    ClearSampleBuffer();
+  }
   // If the ticker hasn't already started, make sure to do so to get
   // the ticks for the runtime profiler.
   if (IsEnabled()) isolate_->logger()->EnsureTickerStarted();
@@ -255,10 +372,14 @@ void RuntimeProfiler::Setup() {
 
 
 void RuntimeProfiler::Reset() {
-  sampler_threshold_ = kSamplerThresholdInit;
-  sampler_threshold_size_factor_ = kSamplerThresholdSizeFactorInit;
-  sampler_ticks_until_threshold_adjustment_ =
-      kSamplerTicksBetweenThresholdAdjustment;
+  if (FLAG_watch_ic_patching) {
+    total_code_generated_ = 0;
+  } else {  // !FLAG_watch_ic_patching
+    sampler_threshold_ = kSamplerThresholdInit;
+    sampler_threshold_size_factor_ = kSamplerThresholdSizeFactorInit;
+    sampler_ticks_until_threshold_adjustment_ =
+        kSamplerTicksBetweenThresholdAdjustment;
+  }
 }
 
 
@@ -295,7 +416,7 @@ void RuntimeProfiler::HandleWakeUp(Isolate* isolate) {
   // undid the decrement done by the profiler thread. Increment again
   // to get the right count of active isolates.
   NoBarrier_AtomicIncrement(&state_, 1);
-  semaphore_->Signal();
+  semaphore.Pointer()->Signal();
 }
 
 
@@ -308,7 +429,7 @@ bool RuntimeProfiler::WaitForSomeIsolateToEnterJS() {
   Atomic32 old_state = NoBarrier_CompareAndSwap(&state_, 0, -1);
   ASSERT(old_state >= -1);
   if (old_state != 0) return false;
-  semaphore_->Wait();
+  semaphore.Pointer()->Wait();
   return true;
 }
 
@@ -324,7 +445,7 @@ void RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(Thread* thread) {
   if (new_state == 0) {
     // The profiler thread is waiting. Wake it up. It must check for
     // stop conditions before attempting to wait again.
-    semaphore_->Signal();
+    semaphore.Pointer()->Signal();
   }
   thread->Join();
   // The profiler thread is now stopped. Undo the increment in case it
@@ -338,7 +459,8 @@ void RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(Thread* thread) {
 void RuntimeProfiler::RemoveDeadSamples() {
   for (int i = 0; i < kSamplerWindowSize; i++) {
     Object* function = sampler_window_[i];
-    if (function != NULL && !HeapObject::cast(function)->IsMarked()) {
+    if (function != NULL &&
+        !Marking::MarkBitFrom(HeapObject::cast(function)).Get()) {
       sampler_window_[i] = NULL;
     }
   }