[compiler] Mark shared functions for optimization

src/compiler.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/compiler.h"
 
 #include <algorithm>
 #include <memory>
 
 #include "src/asmjs/asm-js.h"
@@ skipping 959 matching lines @@
           .ToHandle(&cached_code)) {
     if (FLAG_trace_opt) {
       PrintF("[found optimized code for ");
       function->ShortPrint();
       PrintF(" during unoptimized compile]\n");
     }
     DCHECK(function->shared()->is_compiled());
     return cached_code;
   }
 
+  if (function->shared()->was_marked_for_optimization()) {

[Michael Starzinger, 2016/10/21 11:37:58]

The flag never seems to be cleared. This will mark all instances hot for all
eternity even if we deoptimized multiple times and disabled optimization. I
think we should just clear the flag here eagerly. As soon as at least one
instance within a native context has been optimized, the optimized code map
should contain an entry and the lazy compile stub will pick it up. WDYT?

[Leszek Swirski, 2016/10/21 11:44:13]

That's a very good point, I hadn't considered optimization getting disabled.
Clearing the flag seems like a reasonable thing to do, so done.

+    if (FLAG_trace_opt) {
+      PrintF("[optimizing function ");
+      function->PrintName();
+      PrintF(" eagerly because shared function was previously marked]\n");
+    }
+
+    Handle<Code> opt_code;
+    if (GetOptimizedCode(function, Compiler::NOT_CONCURRENT)
+            .ToHandle(&opt_code)) {
+      return opt_code;
+    }
+  }
+
   if (function->shared()->is_compiled()) {
     return Handle<Code>(function->shared()->code());
   }
 
   if (function->shared()->HasBytecodeArray()) {
     Handle<Code> entry = isolate->builtins()->InterpreterEntryTrampoline();
     function->shared()->ReplaceCode(*entry);
     return entry;
   }
 
@@ skipping 822 matching lines @@
     DCHECK(shared->is_compiled());
     function->set_literals(cached.literals);
   } else if (shared->is_compiled()) {
     // TODO(mvstanton): pass pretenure flag to EnsureLiterals.
     JSFunction::EnsureLiterals(function);
   }
 }
 
 }  // namespace internal
 }  // namespace v8