[Interpreter] Add dispatch counters for each bytecode.

src/interpreter/interpreter-assembler.cc

Index: src/interpreter/interpreter-assembler.cc
diff --git a/src/interpreter/interpreter-assembler.cc b/src/interpreter/interpreter-assembler.cc
index 8e983e24d2a3735aac941fe387791a67107e699c..ffc3026cb26be164482619573e4e85d5ca66ed09 100644
--- a/src/interpreter/interpreter-assembler.cc
+++ b/src/interpreter/interpreter-assembler.cc
@@ -4,6 +4,7 @@
 
 #include "src/interpreter/interpreter-assembler.h"
 
+#include <limits>
 #include <ostream>
 
 #include "src/code-factory.h"
@@ -43,6 +44,9 @@ InterpreterAssembler::InterpreterAssembler(Isolate* isolate, Zone* zone,
   if (FLAG_trace_ignition) {
     TraceBytecode(Runtime::kInterpreterTraceBytecodeEntry);
   }
+  if (FLAG_trace_ignition_dispatches) {
+    TraceBytecodeDispatch();
+  }
 }
 
 InterpreterAssembler::~InterpreterAssembler() {}
@@ -657,6 +661,31 @@ void InterpreterAssembler::TraceBytecode(Runtime::FunctionId function_id) {
               SmiTag(BytecodeOffset()), GetAccumulator());
 }
 
+void InterpreterAssembler::TraceBytecodeDispatch() {
+  Node* counters = ExternalConstant(
+      ExternalReference::interpreter_dispatch_counters(isolate()));
+  Node* counter_offset =
+      IntPtrConstant(static_cast<int>(bytecode_) * sizeof(uintptr_t));
+  Node* old_counter = Load(MachineType::IntPtr(), counters, counter_offset);
+
+  CodeStubAssembler::Label counter_ok(this);
+  CodeStubAssembler::Label counter_saturated(this);
+  CodeStubAssembler::Label end(this);
+
+  Node* counter_reached_max = WordEqual(
+      old_counter, IntPtrConstant(std::numeric_limits<uintptr_t>::max()));
+  Branch(counter_reached_max, &counter_saturated, &counter_ok);
+  Bind(&counter_ok);
+  Node* new_counter = IntPtrAdd(old_counter, IntPtrConstant(1));
+  StoreNoWriteBarrier(kPointerSize == 8 ? MachineRepresentation::kWord64
+                                        : MachineRepresentation::kWord32,
+                      counters, counter_offset, new_counter);
+  Goto(&end);
+  Bind(&counter_saturated);
+  Goto(&end);
+  Bind(&end);
+}
+
 // static
 bool InterpreterAssembler::TargetSupportsUnalignedAccess() {
 #if V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64