LazyVT utils to get original value/source and is_hashable (#144160)

Summary:
X-link: pytorch/pytorch#144160
Approved by: https://github.com/williamwen42, https://github.com/jansel
ghstack dependencies: #144129, #144130, #144141, #144158, #144163

Reviewed By: jeanschmidt

Differential Revision: D67828360

Pulled By: anijain2305

fbshipit-source-id: 60a4daa9e4bd04b9be7a4c3dd4551ea5e13aac86

userbenchmark/dynamo/dynamobench/_dynamo/utils.py

@@ -2063,12 +2063,27 @@ def is_int_specialization_case(value, source):
 
 
 def specialize_symnode(arg):
-    from .variables import ConstantVariable, SymNodeVariable
+    from .variables import ConstantVariable, LazyVariableTracker, SymNodeVariable
 
     # Guard and specialize
+    if isinstance(arg, LazyVariableTracker) and not arg.is_realized():
+        # Find if the arg would be realized as SymNodeVariable later on. If yes,
+        # realize it and specialize. Else return the arg.
+
+        source = arg.original_source()
+        value = arg.original_value()
+
+        is_symnode_vt = is_torch_sym(value) or (
+            not config.specialize_int
+            and type(value) is int
+            and not is_int_specialization_case(value, source)
+        )
+
+        if not is_symnode_vt:
+            return arg
+
     if isinstance(arg, SymNodeVariable):
         return ConstantVariable.create(arg.evaluate_expr())
-
     return arg