Collect type profile for DevTools.

src/interpreter/bytecode-generator.cc

Index: src/interpreter/bytecode-generator.cc
diff --git a/src/interpreter/bytecode-generator.cc b/src/interpreter/bytecode-generator.cc
index 27abb13472cd7bb4b5d4ab7940c19fcd22d7872f..af78a3983600190b2c6f74c789c38382a39d6af6 100644
--- a/src/interpreter/bytecode-generator.cc
+++ b/src/interpreter/bytecode-generator.cc
@@ -2214,18 +2214,34 @@ void BytecodeGenerator::VisitAssignment(Assignment* expr) {
   LhsKind assign_type = Property::GetAssignType(property);
 
   // Evaluate LHS expression.
+  Register lhs_name;

[Yang, 2017/03/09 10:28:27]

Do we have a plan to use a better way to identify variables than names? Variable
names could be ambiguous due to shadowing, and we would need a mapping from
feedback slot to name and source position that we can use when we harvest all
type profile information at once. I wonder whether we can store this mapping in
the feedback metadata.

Maybe we only need the mapping from slot to bytecode offset of the declaration,
and from there we could extract the variable name and the source position from
the bytecode array and source position table.

[Franzi, 2017/03/10 12:14:29]

I'm only passing the name so that I can understand the debug output. My plan is
to not use the name at all. 

+  if (expr->HasCollectTypeProfileSlot()) {
+    lhs_name = register_allocator()->NewRegister();
+  }
+
   switch (assign_type) {
     case VARIABLE:
+      if (expr->HasCollectTypeProfileSlot()) {
+        builder()
+            ->LoadLiteral(expr->target()->AsVariableProxy()->var()->raw_name())
+            .StoreAccumulatorInRegister(lhs_name);
+      }
       // Nothing to do to evaluate variable assignment LHS.
       break;
     case NAMED_PROPERTY: {
       object = VisitForRegisterValue(property->obj());
       name = property->key()->AsLiteral()->AsRawPropertyName();
+      if (expr->HasCollectTypeProfileSlot()) {
+        builder()->LoadLiteral(name).StoreAccumulatorInRegister(lhs_name);
+      }
       break;
     }
     case KEYED_PROPERTY: {
       object = VisitForRegisterValue(property->obj());
       key = VisitForRegisterValue(property->key());
+      if (expr->HasCollectTypeProfileSlot()) {
+        builder()->StoreAccumulatorInRegister(lhs_name);
+      }
       break;
     }
     case NAMED_SUPER_PROPERTY: {
@@ -2238,6 +2254,9 @@ void BytecodeGenerator::VisitAssignment(Assignment* expr) {
       builder()
           ->LoadLiteral(property->key()->AsLiteral()->AsRawPropertyName())
           .StoreAccumulatorInRegister(super_property_args[2]);
+      if (expr->HasCollectTypeProfileSlot()) {
+        builder()->StoreAccumulatorInRegister(lhs_name);
+      }
       break;
     }
     case KEYED_SUPER_PROPERTY: {
@@ -2248,6 +2267,10 @@ void BytecodeGenerator::VisitAssignment(Assignment* expr) {
       VisitForRegisterValue(super_property->home_object(),
                             super_property_args[1]);
       VisitForRegisterValue(property->key(), super_property_args[2]);
+      if (expr->HasCollectTypeProfileSlot()) {
+        builder()->StoreAccumulatorInRegister(lhs_name);
+      }
+
       break;
     }
   }
@@ -2336,6 +2359,14 @@ void BytecodeGenerator::VisitAssignment(Assignment* expr) {
       break;
     }
   }
+
+  // Value is in accumulator.
+  if (expr->HasCollectTypeProfileSlot()) {
+    FeedbackSlot collect_type_feedback_slot = expr->CollectTypeProfileSlot();
+
+    builder()->CollectTypeProfile(lhs_name,
+                                  feedback_index(collect_type_feedback_slot));
+  }
 }
 
 void BytecodeGenerator::VisitYield(Yield* expr) {