[Interpreter] Add dispatch counters for each bytecode.

src/interpreter/interpreter.cc

 // Copyright 2015 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/interpreter/interpreter.h"
 
 #include "src/ast/prettyprinter.h"
 #include "src/code-factory.h"
 #include "src/compiler.h"
 #include "src/factory.h"
@@ skipping 14 matching lines @@
 Interpreter::Interpreter(Isolate* isolate) : isolate_(isolate) {
   memset(&dispatch_table_, 0, sizeof(dispatch_table_));
 }
 
 void Interpreter::Initialize() {
   DCHECK(FLAG_ignition);
   if (IsDispatchTableInitialized()) return;
   Zone zone;
   HandleScope scope(isolate_);
 
+  if (FLAG_ignition_count_handler_dispatches) {
+    memset(handlers_dispatch_counters_, 0, sizeof(handlers_dispatch_counters_));
+  }
+
 #define GENERATE_CODE(Name, ...)                                        \
   {                                                                     \
     InterpreterAssembler assembler(isolate_, &zone, Bytecode::k##Name); \
     Do##Name(&assembler);                                               \
     Handle<Code> code = assembler.GenerateCode();                       \
     dispatch_table_[Bytecodes::ToByte(Bytecode::k##Name)] = *code;      \
     TraceCodegen(code);                                                 \
     LOG_CODE_EVENT(isolate_,                                            \
                    CodeCreateEvent(Logger::BYTECODE_HANDLER_TAG,        \
                                    AbstractCode::cast(*code), #Name));  \
@@ skipping 59 matching lines @@
     bytecodes->Print(os);
     os << std::flush;
   }
 
   info->SetBytecodeArray(bytecodes);
   info->SetCode(info->isolate()->builtins()->InterpreterEntryTrampoline());
   return true;
 }
 
 bool Interpreter::IsDispatchTableInitialized() {
-  if (FLAG_trace_ignition) {
+  if (FLAG_trace_ignition || FLAG_ignition_count_handler_dispatches) {
     // Regenerate table to add bytecode tracing operations.
     return false;
   }
   return dispatch_table_[0] != nullptr;
 }
 
 void Interpreter::TraceCodegen(Handle<Code> code) {
 #ifdef ENABLE_DISASSEMBLER
   if (FLAG_trace_ignition_codegen) {
     OFStream os(stdout);
@@ skipping 1797 matching lines @@
   Node* index = __ LoadRegister(index_reg);
   Node* one = __ SmiConstant(Smi::FromInt(1));
   Node* result = __ SmiAdd(index, one);
   __ SetAccumulator(result);
   __ Dispatch();
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8