[interpreter] Compute and use type info percentage

src/runtime-profiler.cc

 // 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"
@@ skipping 37 matching lines @@
 static const int kOSRCodeSizeAllowancePerTick =
     4 * FullCodeGenerator::kCodeSizeMultiplier;
 static const int kOSRCodeSizeAllowancePerTickIgnition =
     4 * 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;
 
+#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) {
+  switch (reason) {

[rmcilroy, 2016/09/23 08:10:34]

Just call OptimizationReasonToString rather than another switch?

[klaasb, 2016/09/23 08:31:39]

Done.

+#define OPTIMIZATION_REASON_NAMES(Constant, message) \
+  case OptimizationReason::k##Constant:              \
+    return os << #Constant;
+    OPTIMIZATION_REASON_LIST(OPTIMIZATION_REASON_NAMES)
+#undef OPTIMIZATION_REASON_NAMES
+  }
+  UNREACHABLE();
+  return os;
+}
 
 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;
+  int with = 0, gen = 0, interpreter_total = 0;

[rmcilroy, 2016/09/23 08:10:34]

nit - type_vector_ic_count

[klaasb, 2016/09/23 08:31:40]

Done.

   const bool is_interpreted =
       function->shared()->code()->is_interpreter_trampoline_builtin();
 
-  vector->ComputeCounts(&with, &gen, is_interpreted);
+  vector->ComputeCounts(&with, &gen, &interpreter_total, is_interpreted);
+  if (is_interpreted) {
+    *ic_total_count = interpreter_total;

[rmcilroy, 2016/09/23 08:10:34]

DCHECK ic_total_count is zero beforehand

[klaasb, 2016/09/23 08:31:40]

Done.

+  }
   *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.
   }
@@ skipping 11 matching lines @@
       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, const char* reason) {
-  TraceRecompile(function, reason, "optimized");
+void RuntimeProfiler::Optimize(JSFunction* function,
+                               OptimizationReason reason) {
+  DCHECK_NE(reason, OptimizationReason::kDoNotOptimize);
+  TraceRecompile(function, OptimizationReasonToString(reason), "optimized");
   function->AttemptConcurrentOptimization();
 }
 
-void RuntimeProfiler::Baseline(JSFunction* function, const char* reason) {
-  TraceRecompile(function, reason, "baseline");
+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) {
@@ skipping 98 matching lines @@
   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, "hot and stable");
+      Optimize(function, OptimizationReason::kHotAndStable);
     } else if (ticks >= kTicksWhenNotEnoughTypeInfo) {
-      Optimize(function, "not much type info but very hot");
+      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, "small function");
+      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 (MaybeOSRIgnition(function, frame)) return;
+
   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.
-
-  if (FLAG_always_osr) {
-    AttemptOnStackReplacement(frame, AbstractCode::kMaxLoopNestingMarker);
-    // Fall through and do a normal baseline compile as well.
-  } else if (!frame->is_optimized() &&
-             (function->IsMarkedForBaseline() ||
-              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;
-  }
-
   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, "hot enough for baseline");
+    Baseline(function, OptimizationReason::kHotEnoughForBaseline);
   }
 }
 
 void RuntimeProfiler::MaybeOptimizeIgnition(JSFunction* function,
                                             JavaScriptFrame* frame) {
   if (function->IsInOptimizationQueue()) return;
 
+  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;
+
+  auto reason = OptimizationHeuristicIgnition(function, frame);

[rmcilroy, 2016/09/23 08:10:34]

Don't use auto unless it improves readability
(https://google.github.io/styleguide/cppguide.html#auto) - use
OptimizationReason here.

[klaasb, 2016/09/23 08:31:40]

Done.

+
+  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.
 
   if (FLAG_always_osr) {
     AttemptOnStackReplacement(frame, AbstractCode::kMaxLoopNestingMarker);
-    // Fall through and do a normal optimized compile as well.
+    // Do a normal baseline/optimized compile as well.
+    return false;

[rmcilroy, 2016/09/23 08:10:34]

Hmm, not keen on this. Could you just pull out the FLAG_always_osr case and
inline to the functions so it's still obvious that both OSR and
optimize/baseline happens.

[klaasb, 2016/09/23 08:31:40]

Done.

   } else if (!frame->is_optimized() &&
-             (function->IsMarkedForBaseline() ||
+             ((function->IsMarkedForBaseline() &&
+               OptimizationHeuristicIgnition(function, frame) !=
+                   OptimizationReason::kDoNotOptimize) ||

[rmcilroy, 2016/09/23 08:10:34]

Could you pull this out to a separate local for clarity

[klaasb, 2016/09/23 08:31:40]

Done.

               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;
+    return true;
   }
+  return false;
+}
 
-  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 RuntimeProfiler::OptimizationHeuristicIgnition(
+    JSFunction* function, JavaScriptFrame* frame) {
+  SharedFunctionInfo* shared = function->shared();
+  int ticks = shared->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, "hot and stable");
+      return OptimizationReason::kHotAndStable;
     } else if (ticks >= kTicksWhenNotEnoughTypeInfo) {
-      Optimize(function, "not much type info but very hot");
+      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;
     }
   }
   // TODO(rmcilroy): Consider whether we should optimize small functions when
   // they are first seen on the stack (e.g., kMaxSizeEarlyOpt).
+  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
@@ skipping 27 matching lines @@
         MaybeOptimizeIgnition(function, frame);
       }
     } else {
       DCHECK_EQ(next_tier, Compiler::OPTIMIZED);
       MaybeOptimizeFullCodegen(function, frame, frame_count);
     }
   }
   any_ic_changed_ = false;
 }
 
-
 }  // namespace internal
 }  // namespace v8