In optimized code use IC calls for instance calls that have no IC data instead of deoptimizing. The…

runtime/vm/code_generator.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/code_generator.h"
 
 #include "vm/assembler_macros.h"
 #include "vm/ast.h"
 #include "vm/code_patcher.h"
 #include "vm/compiler.h"
@@ skipping 29 matching lines @@
 DEFINE_FLAG(bool, trace_runtime_calls, false, "Trace runtime calls");
 DEFINE_FLAG(int, optimization_counter_threshold, 2000,
     "Function's usage-counter value before it is optimized, -1 means never");
 DECLARE_FLAG(bool, enable_type_checks);
 DECLARE_FLAG(bool, trace_type_checks);
 DECLARE_FLAG(bool, report_usage_count);
 DECLARE_FLAG(int, deoptimization_counter_threshold);
 DEFINE_FLAG(charp, optimization_filter, NULL, "Optimize only named function");
 DEFINE_FLAG(bool, trace_failed_optimization_attempts, false,
     "Traces all failed optimization attempts");
+DEFINE_FLAG(bool, trace_optimized_ic_calls, false,
+    "Trace IC calls in optimized code.");
+DEFINE_FLAG(int, reoptimization_counter_threshold, 2000,
+    "Counter threshold before a function gets reoptimized.");
 DEFINE_FLAG(int, max_subtype_cache_entries, 100,
     "Maximum number of subtype cache entries (number of checks cached).");
 
 
 DEFINE_RUNTIME_ENTRY(TraceFunctionEntry, 1) {
   ASSERT(arguments.Count() == kTraceFunctionEntryRuntimeEntry.argument_count());
   const Function& function = Function::CheckedHandle(arguments.At(0));
   const String& function_name = String::Handle(function.name());
   const String& class_name =
       String::Handle(Class::Handle(function.Owner()).Name());
@@ skipping 1422 matching lines @@
     const Function& caller_function = Function::Handle(
         caller_frame->LookupDartFunction());
     const Code& code = Code::Handle(caller_frame->LookupDartCode());
     OS::Print("  -> caller: %s (%s)\n",
         caller_function.ToFullyQualifiedCString(),
         code.is_optimized() ? "optimized" : "unoptimized");
   }
 }
 
 
+DEFINE_RUNTIME_ENTRY(TraceICCall, 2) {
+  ASSERT(arguments.Count() ==
+         kTraceICCallRuntimeEntry.argument_count());
+  const ICData& ic_data = ICData::CheckedHandle(arguments.At(0));
+  const Function& function = Function::CheckedHandle(arguments.At(1));
+  DartFrameIterator iterator;
+  StackFrame* frame = iterator.NextFrame();
+  ASSERT(frame != NULL);
+  OS::Print("IC call @%#"Px": ICData: %p cnt:%"Pd" nchecks: %"Pd" %s %s\n",
+      frame->pc(),
+      ic_data.raw(),
+      function.usage_counter(),
+      ic_data.NumberOfChecks(),
+      ic_data.is_closure_call() ? "closure" : "",
+      function.ToFullyQualifiedCString());
+}
 
-// Only unoptimized code has invocation counter threshold checking.
-// Once the invocation counter threshold is reached any entry into the
-// unoptimized code is redirected to this function.
+
+// This is called from function that needs to be optimized.
+// The requesting function can be already optimized (reoptimization).
 DEFINE_RUNTIME_ENTRY(OptimizeInvokedFunction, 1) {
-  const intptr_t kLowInvocationCount = -100000000;
   ASSERT(arguments.Count() ==
          kOptimizeInvokedFunctionRuntimeEntry.argument_count());
+  const intptr_t kLowInvocationCount = -100000000;
   const Function& function = Function::CheckedHandle(arguments.At(0));
   if (isolate->debugger()->IsActive()) {
     // We cannot set breakpoints in optimized code, so do not optimize
     // the function.
     function.set_usage_counter(0);
     return;
   }
   if (function.deoptimization_counter() >=
       FLAG_deoptimization_counter_threshold) {
     if (FLAG_trace_failed_optimization_attempts) {
       PrintCaller("Too Many Deoptimizations");
     }
     // TODO(srdjan): Investigate excessive deoptimization.
     function.set_usage_counter(kLowInvocationCount);
     return;
   }
-  if (function.HasOptimizedCode()) {
-    // The caller has been already optimized, the caller is probably in
-    // a loop or in a recursive call chain.
-    // Leave the usage_counter at the limit so that the count test knows that
-    // method is optimized.
-    if (FLAG_trace_failed_optimization_attempts) {
-      PrintCaller("Has Optimized Code");
-    }
-    // TODO(srdjan): Enable reoptimizing optimized code, but most recognize
-    // that reoptimization was not already applied.
-    return;
-  }
   if ((FLAG_optimization_filter != NULL) &&
       (strstr(function.ToFullyQualifiedCString(),
               FLAG_optimization_filter) == NULL)) {
     function.set_usage_counter(kLowInvocationCount);
     return;
   }
   if (function.is_optimizable()) {
-    // Compilation patches the entry of unoptimized code.
-    ASSERT(!function.HasOptimizedCode());
     const Error& error =
         Error::Handle(Compiler::CompileOptimizedFunction(function));
     if (!error.IsNull()) {
       Exceptions::PropagateError(error);
     }
     const Code& optimized_code = Code::Handle(function.CurrentCode());
     ASSERT(!optimized_code.IsNull());
-    function.set_usage_counter(0);
+    // Set usage counter for reoptimization.
+    function.set_usage_counter(
+        function.usage_counter() - FLAG_reoptimization_counter_threshold);
   } else {
     if (FLAG_trace_failed_optimization_attempts) {
       PrintCaller("Not Optimizable");
     }
     // TODO(5442338): Abort as this should not happen.
     function.set_usage_counter(kLowInvocationCount);
   }
 }
 
 
@@ skipping 344 matching lines @@
     intptr_t line, column;
     script.GetTokenLocation(token_pos, &line, &column);
     String& line_string = String::Handle(script.GetLine(line));
     OS::Print("  Function: %s\n", top_function.ToFullyQualifiedCString());
     OS::Print("  Line %"Pd": '%s'\n", line, line_string.ToCString());
   }
 }
 
 
 }  // namespace dart