1 files changed, 47 insertions, 10 deletions
diff --git a/deps/v8/src/compiler/backend/bitcast-elider.cc b/deps/v8/src/compiler/backend/bitcast-elider.cc
index 263e3d691b..403e6d318c 100644
--- a/deps/v8/src/compiler/backend/bitcast-elider.cc
+++ b/deps/v8/src/compiler/backend/bitcast-elider.cc
@@ -20,6 +20,37 @@ bool IsBitcast(Node* node) {
          node->opcode() == IrOpcode::kBitcastWordToTaggedSigned;
 }
 
+bool OwnedByWord32Op(Node* node) {
+#if V8_TARGET_ARCH_LOONG64 || V8_TARGET_ARCH_MIPS64
+  return false;
+#else
+  for (Node* const use : node->uses()) {
+    switch (use->opcode()) {
+      case IrOpcode::kWord32Equal:
+      case IrOpcode::kInt32LessThan:
+      case IrOpcode::kInt32LessThanOrEqual:
+      case IrOpcode::kUint32LessThan:
+      case IrOpcode::kUint32LessThanOrEqual:
+      case IrOpcode::kChangeInt32ToInt64:
+#define Word32Op(Name) case IrOpcode::k##Name:
+        MACHINE_BINOP_32_LIST(Word32Op)
+#undef Word32Op
+        break;
+      default:
+        return false;
+    }
+  }
+  return true;
+#endif
+}
+
+void Replace(Node* node, Node* replacement) {
+  for (Edge edge : node->use_edges()) {
+    edge.UpdateTo(replacement);
+  }
+  node->Kill();
+}
+
 }  // namespace
 
 void BitcastElider::Enqueue(Node* node) {
@@ -28,18 +59,21 @@ void BitcastElider::Enqueue(Node* node) {
   to_visit_.push(node);
 }
 
+void BitcastElider::Revisit(Node* node) { to_visit_.push(node); }
+
 void BitcastElider::VisitNode(Node* node) {
   for (int i = 0; i < node->InputCount(); i++) {
     Node* input = node->InputAt(i);
-    bool should_replace_input = false;
-    while (IsBitcast(input)) {
-      input = input->InputAt(0);
-      should_replace_input = true;
-    }
-    if (should_replace_input) {
-      node->ReplaceInput(i, input);
+    if (input->opcode() == IrOpcode::kTruncateInt64ToInt32 &&
+        OwnedByWord32Op(input)) {
+      Replace(input, input->InputAt(0));
+      Revisit(node);
+    } else if (is_builtin_ && IsBitcast(input)) {
+      Replace(input, input->InputAt(0));
+      Revisit(node);
+    } else {
+      Enqueue(input);
     }
-    Enqueue(input);
   }
 }
 
@@ -52,8 +86,11 @@ void BitcastElider::ProcessGraph() {
   }
 }
 
-BitcastElider::BitcastElider(Zone* zone, Graph* graph)
-    : graph_(graph), to_visit_(zone), seen_(graph, 2) {}
+BitcastElider::BitcastElider(Zone* zone, Graph* graph, bool is_builtin)
+    : graph_(graph),
+      to_visit_(zone),
+      seen_(graph, 2),
+      is_builtin_(is_builtin) {}
 
 void BitcastElider::Reduce() { ProcessGraph(); }