Revert of [turbofan] inline %StringIteratorPrototype%.next in JSBuiltinReducer.

src/compiler/js-builtin-reducer.cc

Index: src/compiler/js-builtin-reducer.cc
diff --git a/src/compiler/js-builtin-reducer.cc b/src/compiler/js-builtin-reducer.cc
index 78c3286d059e3d2bf26d98cc8c44121e18230615..762020438878fdbc5566ba07848fd601c870b6ca 100644
--- a/src/compiler/js-builtin-reducer.cc
+++ b/src/compiler/js-builtin-reducer.cc
@@ -1026,139 +1026,6 @@
   return NoChange();
 }
 
-Reduction JSBuiltinReducer::ReduceStringIteratorNext(Node* node) {
-  Node* receiver = NodeProperties::GetValueInput(node, 1);
-  Node* effect = NodeProperties::GetEffectInput(node);
-  Node* control = NodeProperties::GetControlInput(node);
-  Node* context = NodeProperties::GetContextInput(node);
-  if (HasInstanceTypeWitness(receiver, effect, JS_STRING_ITERATOR_TYPE)) {
-    Node* string = effect = graph()->NewNode(
-        simplified()->LoadField(AccessBuilder::ForJSStringIteratorString()),
-        receiver, effect, control);
-    Node* index = effect = graph()->NewNode(
-        simplified()->LoadField(AccessBuilder::ForJSStringIteratorIndex()),
-        receiver, effect, control);
-    Node* length = effect = graph()->NewNode(
-        simplified()->LoadField(AccessBuilder::ForStringLength()), string,
-        effect, control);
-
-    // branch0: if (index < length)
-    Node* check0 =
-        graph()->NewNode(simplified()->NumberLessThan(), index, length);
-    Node* branch0 =
-        graph()->NewNode(common()->Branch(BranchHint::kTrue), check0, control);
-
-    Node* etrue0 = effect;
-    Node* if_true0 = graph()->NewNode(common()->IfTrue(), branch0);
-    Node* done_true;
-    Node* vtrue0;
-    {
-      done_true = jsgraph()->FalseConstant();
-      Node* lead = graph()->NewNode(simplified()->StringCharCodeAt(), string,
-                                    index, if_true0);
-
-      // branch1: if ((lead & 0xFC00) === 0xD800)
-      Node* check1 = graph()->NewNode(
-          simplified()->NumberEqual(),
-          graph()->NewNode(simplified()->NumberBitwiseAnd(), lead,
-                           jsgraph()->Int32Constant(0xFC00)),
-          jsgraph()->Int32Constant(0xD800));
-      Node* branch1 = graph()->NewNode(common()->Branch(BranchHint::kFalse),
-                                       check1, if_true0);
-      Node* if_true1 = graph()->NewNode(common()->IfTrue(), branch1);
-      Node* vtrue1;
-      {
-        Node* next_index = graph()->NewNode(simplified()->NumberAdd(), index,
-                                            jsgraph()->OneConstant());
-        // branch2: if ((index + 1) < length)
-        Node* check2 = graph()->NewNode(simplified()->NumberLessThan(),
-                                        next_index, length);
-        Node* branch2 = graph()->NewNode(common()->Branch(BranchHint::kTrue),
-                                         check2, if_true1);
-        Node* if_true2 = graph()->NewNode(common()->IfTrue(), branch2);
-        Node* vtrue2;
-        {
-          Node* trail = graph()->NewNode(simplified()->StringCharCodeAt(),
-                                         string, next_index, if_true2);
-          // branch3: if ((trail & 0xFC00) === 0xDC00)
-          Node* check3 = graph()->NewNode(
-              simplified()->NumberEqual(),
-              graph()->NewNode(simplified()->NumberBitwiseAnd(), trail,
-                               jsgraph()->Int32Constant(0xFC00)),
-              jsgraph()->Int32Constant(0xDC00));
-          Node* branch3 = graph()->NewNode(common()->Branch(BranchHint::kTrue),
-                                           check3, if_true2);
-          Node* if_true3 = graph()->NewNode(common()->IfTrue(), branch3);
-          Node* vtrue3;
-          {
-            vtrue3 = graph()->NewNode(
-                simplified()->NumberBitwiseOr(),
-                graph()->NewNode(simplified()->NumberShiftLeft(), trail,
-                                 jsgraph()->Int32Constant(16)),
-                lead);
-          }
-
-          Node* if_false3 = graph()->NewNode(common()->IfFalse(), branch3);
-          Node* vfalse3 = lead;
-          if_true2 = graph()->NewNode(common()->Merge(2), if_true3, if_false3);
-          vtrue2 =
-              graph()->NewNode(common()->Phi(MachineRepresentation::kWord32, 2),
-                               vtrue3, vfalse3, if_true2);
-        }
-
-        Node* if_false2 = graph()->NewNode(common()->IfFalse(), branch2);
-        Node* vfalse2 = lead;
-        if_true1 = graph()->NewNode(common()->Merge(2), if_true2, if_false2);
-        vtrue1 =
-            graph()->NewNode(common()->Phi(MachineRepresentation::kWord32, 2),
-                             vtrue2, vfalse2, if_true1);
-      }
-
-      Node* if_false1 = graph()->NewNode(common()->IfFalse(), branch1);
-      Node* vfalse1 = lead;
-      if_true0 = graph()->NewNode(common()->Merge(2), if_true1, if_false1);
-      vtrue0 =
-          graph()->NewNode(common()->Phi(MachineRepresentation::kWord32, 2),
-                           vtrue1, vfalse1, if_true0);
-      vtrue0 = graph()->NewNode(
-          simplified()->StringFromCodePoint(UnicodeEncoding::UTF16), vtrue0);
-
-      // Update iterator.[[NextIndex]]
-      Node* char_length = etrue0 = graph()->NewNode(
-          simplified()->LoadField(AccessBuilder::ForStringLength()), vtrue0,
-          etrue0, if_true0);
-      index = graph()->NewNode(simplified()->NumberAdd(), index, char_length);
-      etrue0 = graph()->NewNode(
-          simplified()->StoreField(AccessBuilder::ForJSStringIteratorIndex()),
-          receiver, index, etrue0, if_true0);
-    }
-
-    Node* if_false0 = graph()->NewNode(common()->IfFalse(), branch0);
-    Node* done_false;
-    Node* vfalse0;
-    {
-      vfalse0 = jsgraph()->UndefinedConstant();
-      done_false = jsgraph()->TrueConstant();
-    }
-
-    control = graph()->NewNode(common()->Merge(2), if_true0, if_false0);
-    effect = graph()->NewNode(common()->EffectPhi(2), etrue0, effect, control);
-    Node* value =
-        graph()->NewNode(common()->Phi(MachineRepresentation::kTagged, 2),
-                         vtrue0, vfalse0, control);
-    Node* done =
-        graph()->NewNode(common()->Phi(MachineRepresentation::kTagged, 2),
-                         done_true, done_false, control);
-
-    value = effect = graph()->NewNode(javascript()->CreateIterResultObject(),
-                                      value, done, context, effect);
-
-    ReplaceWithValue(node, value, effect, control);
-    return Replace(value);
-  }
-  return NoChange();
-}
-
 Reduction JSBuiltinReducer::ReduceArrayBufferViewAccessor(
     Node* node, InstanceType instance_type, FieldAccess const& access) {
   Node* receiver = NodeProperties::GetValueInput(node, 1);
@@ -1328,8 +1195,6 @@
       return ReduceStringCharAt(node);
     case kStringCharCodeAt:
       return ReduceStringCharCodeAt(node);
-    case kStringIteratorNext:
-      return ReduceStringIteratorNext(node);
     case kDataViewByteLength:
       return ReduceArrayBufferViewAccessor(
           node, JS_DATA_VIEW_TYPE,
@@ -1389,10 +1254,6 @@
   return jsgraph()->simplified();
 }
 
-JSOperatorBuilder* JSBuiltinReducer::javascript() const {
-  return jsgraph()->javascript();
-}
-
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8