[Relax] Add new NN allgather operator

python/tvm/relax/frontend/nn/op.py

@@ -1719,6 +1719,28 @@ def ccl_allreduce(x: Tensor, op_type: str = "sum", in_group: bool = True, name="
     return wrap_nested(_op.ccl.allreduce(x._expr, op_type, in_group), name)
 
 
+def ccl_allgather(x: Tensor, num_workers: int, name="ccl_allgather"):
+    """CCL Allgather operator
+
+    Parameters
+    ----------
+    x : relax.Expr
+      The input tensor.
+
+    num_workers : int
+      Number of workers.
+
+    name : str
+        Name hint for this operation.
+
+    Returns
+    -------
+    result : Tensor
+      The result tensor of allgather.
+    """
+    return wrap_nested(_op.ccl.allgather(x._expr, num_workers), name)
+
+
 def ccl_broadcast_from_worker0(x: Tensor, name="broadcast_from_worker"):
     """Broadcast data from worker-0 to all other workers.