Revert of [turbofan] Utilize String comparison feedback.

src/compiler/js-typed-lowering.cc

Index: src/compiler/js-typed-lowering.cc
diff --git a/src/compiler/js-typed-lowering.cc b/src/compiler/js-typed-lowering.cc
index 3ad838c33198f8bc4b03c4bb37b378530d60c087..00cf092175889b56919424d94249c7396de8acc7 100644
--- a/src/compiler/js-typed-lowering.cc
+++ b/src/compiler/js-typed-lowering.cc
@@ -72,16 +72,6 @@
         case CompareOperationHint::kString:
           break;
       }
-    }
-    return false;
-  }
-
-  bool IsStringCompareOperation() {
-    if (lowering_->flags() & JSTypedLowering::kDeoptimizationEnabled) {
-      DCHECK_EQ(1, node_->op()->EffectOutputCount());
-      return (CompareOperationHintOf(node_->op()) ==
-              CompareOperationHint::kString) &&
-             BothInputsMaybe(Type::String());
     }
     return false;
   }
@@ -112,23 +102,6 @@
       }
     }
     return false;
-  }
-
-  // Checks that both inputs are String, and if we don't know statically that
-  // one side is already a String, insert a CheckString node.
-  void CheckInputsToString() {
-    if (!left_type()->Is(Type::String())) {
-      Node* left_input = graph()->NewNode(simplified()->CheckString(), left(),
-                                          effect(), control());
-      node_->ReplaceInput(0, left_input);
-      update_effect(left_input);
-    }
-    if (!right_type()->Is(Type::String())) {
-      Node* right_input = graph()->NewNode(simplified()->CheckString(), right(),
-                                           effect(), control());
-      node_->ReplaceInput(1, right_input);
-      update_effect(right_input);
-    }
   }
 
   void ConvertInputsToNumber() {
@@ -344,10 +317,6 @@
 
   bool BothInputsAre(Type* t) { return LeftInputIs(t) && RightInputIs(t); }
 
-  bool BothInputsMaybe(Type* t) {
-    return left_type()->Maybe(t) && right_type()->Maybe(t);
-  }
-
   bool OneInputCannotBe(Type* t) {
     return !left_type()->Maybe(t) || !right_type()->Maybe(t);
   }
@@ -778,10 +747,6 @@
     r.ConvertInputsToNumber();
     less_than = simplified()->NumberLessThan();
     less_than_or_equal = simplified()->NumberLessThanOrEqual();
-  } else if (r.IsStringCompareOperation()) {
-    r.CheckInputsToString();
-    less_than = simplified()->StringLessThan();
-    less_than_or_equal = simplified()->StringLessThanOrEqual();
   } else {
     return NoChange();
   }
@@ -920,9 +885,6 @@
         simplified()->SpeculativeNumberEqual(hint), invert, Type::Boolean());
   } else if (r.BothInputsAre(Type::Number())) {
     return r.ChangeToPureOperator(simplified()->NumberEqual(), invert);
-  } else if (r.IsStringCompareOperation()) {
-    r.CheckInputsToString();
-    return r.ChangeToPureOperator(simplified()->StringEqual(), invert);
   }
   return NoChange();
 }
@@ -985,9 +947,6 @@
         simplified()->SpeculativeNumberEqual(hint), invert, Type::Boolean());
   } else if (r.BothInputsAre(Type::Number())) {
     return r.ChangeToPureOperator(simplified()->NumberEqual(), invert);
-  } else if (r.IsStringCompareOperation()) {
-    r.CheckInputsToString();
-    return r.ChangeToPureOperator(simplified()->StringEqual(), invert);
   }
   return NoChange();
 }