1 files changed, 46 insertions, 1 deletions

diff --git a/deps/v8/src/maglev/maglev-basic-block.h b/deps/v8/src/maglev/maglev-basic-block.h
index 7f583e5bb2..d40b3c5c2e 100644
--- a/deps/v8/src/maglev/maglev-basic-block.h
+++ b/deps/v8/src/maglev/maglev-basic-block.h
@@ -7,6 +7,7 @@
 
 #include <vector>
 
+#include "src/base/small-vector.h"
 #include "src/codegen/label.h"
 #include "src/maglev/maglev-interpreter-frame-state.h"
 #include "src/maglev/maglev-ir.h"
@@ -26,7 +27,14 @@ class BasicBlock {
 
   uint32_t first_id() const {
     if (has_phi()) return phis()->first()->id();
-    return nodes_.is_empty() ? control_node()->id() : nodes_.first()->id();
+    if (nodes_.is_empty()) {
+      return control_node()->id();
+    }
+    auto node = nodes_.first();
+    while (node && node->Is<Identity>()) {
+      node = node->NextNode();
+    }
+    return node ? node->id() : control_node()->id();
   }
 
   uint32_t FirstNonGapMoveId() const {
@@ -34,6 +42,7 @@ class BasicBlock {
     if (!nodes_.is_empty()) {
       for (const Node* node : nodes_) {
         if (IsGapMoveNode(node->opcode())) continue;
+        if (node->Is<Identity>()) continue;
         return node->id();
       }
     }
@@ -52,11 +61,17 @@ class BasicBlock {
 
   bool is_edge_split_block() const { return is_edge_split_block_; }
 
+  bool is_loop() const { return has_state() && state()->is_loop(); }
+
   MergePointRegisterState& edge_split_block_register_state() {
     DCHECK(is_edge_split_block());
     return *edge_split_block_register_state_;
   }
 
+  bool contains_node_id(NodeIdT id) const {
+    return id >= first_id() && id <= control_node()->id();
+  }
+
   void set_edge_split_block_register_state(
       MergePointRegisterState* register_state) {
     DCHECK(is_edge_split_block());
@@ -73,6 +88,13 @@ class BasicBlock {
     edge_split_block_register_state_ = nullptr;
   }
 
+  bool is_start_block_of_switch_case() const {
+    return is_start_block_of_switch_case_;
+  }
+  void set_start_block_of_switch_case(bool value) {
+    is_start_block_of_switch_case_ = value;
+  }
+
   Phi::List* phis() const {
     DCHECK(has_phi());
     return state_->phis();
@@ -90,6 +112,8 @@ class BasicBlock {
     control_node()->Cast<UnconditionalControlNode>()->set_predecessor_id(id);
   }
 
+  base::SmallVector<BasicBlock*, 2> successors() const;
+
   Label* label() { return &label_; }
   MergePointInterpreterFrameState* state() const {
     DCHECK(has_state());
@@ -103,6 +127,7 @@ class BasicBlock {
 
  private:
   bool is_edge_split_block_ = false;
+  bool is_start_block_of_switch_case_ = false;
   Node::List nodes_;
   ControlNode* control_node_;
   union {
@@ -112,6 +137,26 @@ class BasicBlock {
   Label label_;
 };
 
+inline base::SmallVector<BasicBlock*, 2> BasicBlock::successors() const {
+  ControlNode* control = control_node();
+  if (auto node = control->TryCast<UnconditionalControlNode>()) {
+    return {node->target()};
+  } else if (auto node = control->TryCast<BranchControlNode>()) {
+    return {node->if_true(), node->if_false()};
+  } else if (auto node = control->TryCast<Switch>()) {
+    base::SmallVector<BasicBlock*, 2> succs;
+    for (int i = 0; i < node->size(); i++) {
+      succs.push_back(node->targets()[i].block_ptr());
+    }
+    if (node->has_fallthrough()) {
+      succs.push_back(node->fallthrough());
+    }
+    return succs;
+  } else {
+    return base::SmallVector<BasicBlock*, 2>();
+  }
+}
+
 }  // namespace maglev
 }  // namespace internal
 }  // namespace v8