[Python-checkins] Document LOAD_FAST_CHECK opcode (#93498)

[sweeneyde]

https://github.com/python/cpython/commit/4082c8e298a244edf6771839334372a47ece721d
commit: 4082c8e298a244edf6771839334372a47ece721d
branch: main
author: Dennis Sweeney <36520290+sweeneyde at users.noreply.github.com>
committer: sweeneyde <36520290+sweeneyde at users.noreply.github.com>
date: 2022-06-05T11:24:09-04:00
summary:

Document LOAD_FAST_CHECK opcode (#93498)

files:
M Doc/library/dis.rst

diff --git a/Doc/library/dis.rst b/Doc/library/dis.rst
index 313870ffa4de6..9163d1a4421a8 100644
--- a/Doc/library/dis.rst
+++ b/Doc/library/dis.rst
@@ -1042,6 +1042,17 @@ iterations of the loop.
 
    Pushes a reference to the local ``co_varnames[var_num]`` onto the stack.
 
+   .. versionchanged:: 3.12
+      This opcode is now only used in situations where the local variable is
+      guaranteed to be initialized. It cannot raise :exc:`UnboundLocalError`.
+
+.. opcode:: LOAD_FAST_CHECK (var_num)
+
+   Pushes a reference to the local ``co_varnames[var_num]`` onto the stack,
+   raising an :exc:`UnboundLocalError` if the local variable has not been
+   initialized.
+
+   .. versionadded:: 3.12
 
 .. opcode:: STORE_FAST (var_num)