[Crankshaft] Fine tune merging of Ignition and FCG feedback for binary/compare ops.

Ignition does not collect information about lhs and rhs types. It  collects
information about the combined type of lhs, rhs and result types. Since ignition
combines the feedback, sometimes we may collect less precise information than
FCG. This impacts performance of some benchmarks like audio-beat-detection. This
cl tries to mitigate this affect by passing only full-codegen feedback when the
combined FCG feedback is same as the feedback collected by ignition.

BUG=

Review-Url: https://codereview.chromium.org/2488983002
Cr-Commit-Position: refs/heads/master@{#40888}

src/type-info.cc

@@ -220,9 +220,8 @@ AstType* BinaryOpFeedbackToType(int hint) {
       return AstType::Number();
     case BinaryOperationFeedback::kString:
       return AstType::String();
-    // TODO(mythria): Merge Number and NumberOrOddball feedback, after
-    // fixing crankshaft to handle Oddballs along with Numbers.
     case BinaryOperationFeedback::kNumberOrOddball:
+      return AstType::NumberOrOddball();
     case BinaryOperationFeedback::kAny:
     default:
       return AstType::Any();
@@ -264,14 +263,33 @@ void TypeFeedbackOracle::CompareType(TypeFeedbackId id, FeedbackVectorSlot slot,
     CompareICStub stub(code->stub_key(), isolate());
     AstType* left_type_from_ic =
         CompareICState::StateToType(zone(), stub.left());
-    *left_type = AstType::Union(*left_type, left_type_from_ic, zone());
     AstType* right_type_from_ic =
         CompareICState::StateToType(zone(), stub.right());
-    *right_type = AstType::Union(*right_type, right_type_from_ic, zone());
     AstType* combined_type_from_ic =
         CompareICState::StateToType(zone(), stub.state(), map);
-    *combined_type =
-        AstType::Union(*combined_type, combined_type_from_ic, zone());
+    // Full-codegen collects lhs and rhs feedback seperately and Crankshaft
+    // could use this information to optimize better. So if combining the
+    // feedback has made the feedback less precise, we should use the feedback
+    // only from Full-codegen. If the union of the feedback from Full-codegen
+    // is same as that of Ignition, there is no need to combine feedback from
+    // from Ignition.
+    AstType* combined_type_from_fcg = AstType::Union(
+        left_type_from_ic,
+        AstType::Union(right_type_from_ic, combined_type_from_ic, zone()),
+        zone());
+    if (combined_type_from_fcg == *left_type) {
+      // Full-codegen collects information about lhs, rhs and result types
+      // seperately. So just retain that information.
+      *left_type = left_type_from_ic;
+      *right_type = right_type_from_ic;
+      *combined_type = combined_type_from_ic;
+    } else {
+      // Combine Ignition and Full-codegen feedbacks.
+      *left_type = AstType::Union(*left_type, left_type_from_ic, zone());
+      *right_type = AstType::Union(*right_type, right_type_from_ic, zone());
+      *combined_type =
+          AstType::Union(*combined_type, combined_type_from_ic, zone());
+    }
   }
 }
 
@@ -313,9 +331,29 @@ void TypeFeedbackOracle::BinaryType(TypeFeedbackId id, FeedbackVectorSlot slot,
   BinaryOpICState state(isolate(), code->extra_ic_state());
   DCHECK_EQ(op, state.op());
 
-  *left = AstType::Union(*left, state.GetLeftType(), zone());
-  *right = AstType::Union(*right, state.GetRightType(), zone());
-  *result = AstType::Union(*result, state.GetResultType(), zone());
+  // Full-codegen collects lhs and rhs feedback seperately and Crankshaft
+  // could use this information to optimize better. So if combining the
+  // feedback has made the feedback less precise, we should use the feedback
+  // only from Full-codegen. If the union of the feedback from Full-codegen
+  // is same as that of Ignition, there is no need to combine feedback from
+  // from Ignition.
+  AstType* combined_type_from_fcg = AstType::Union(
+      state.GetLeftType(),
+      AstType::Union(state.GetRightType(), state.GetResultType(), zone()),
+      zone());
+  if (combined_type_from_fcg == *left) {
+    // Full-codegen collects information about lhs, rhs and result types
+    // seperately. So just retain that information.
+    *left = state.GetLeftType();
+    *right = state.GetRightType();
+    *result = state.GetResultType();
+  } else {
+    // Combine Ignition and Full-codegen feedback.
+    *left = AstType::Union(*left, state.GetLeftType(), zone());
+    *right = AstType::Union(*right, state.GetRightType(), zone());
+    *result = AstType::Union(*result, state.GetResultType(), zone());
+  }
+  // Ignition does not collect this feedback.
   *fixed_right_arg = state.fixed_right_arg();
 
   AllocationSite* first_allocation_site = code->FindFirstAllocationSite();