diff --git a/llvm/docs/BitCodeFormat.rst b/llvm/docs/BitCodeFormat.rst
--- a/llvm/docs/BitCodeFormat.rst
+++ b/llvm/docs/BitCodeFormat.rst
@@ -1058,7 +1058,16 @@
 * code 56: ``nocf_check``
 * code 57: ``optforfuzzing``
 * code 58: ``shadowcallstack``
+* code 59: ``speculative_load_hardening``
+* code 60: ``immarg``
+* code 61: ``willreturn``
+* code 62: ``nofree``
+* code 63: ``nosync``
 * code 64: ``sanitize_memtag``
+* code 65: ``preallocated``
+* code 66: ``no_merge``
+* code 67: ``null_pointer_is_valid``
+* code 68: ``frozen``
 
 .. note::
   The ``allocsize`` attribute has a special encoding for its arguments. Its two
diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -1252,6 +1252,12 @@
     only valid on intrinsic declarations and cannot be applied to a
     call site or arbitrary function.
 
+``"frozen"``
+    This attribute indicates that every bit of the parameter is required by
+    the ABI to be initialized and never poison. Values that would violate this
+    requirement include structures with padding bits, unions with active
+    members smaller than their size, and scalars which were never initialized.
+
 .. _gc:
 
 Garbage Collector Strategy Names
@@ -3656,6 +3662,8 @@
 -  The condition operand of a :ref:`br <i_br>` instruction.
 -  The callee operand of a :ref:`call <i_call>` or :ref:`invoke <i_invoke>`
    instruction.
+-  Arguments and return values of function calls, when those operands
+   are marked with the ``frozen`` attribute.
 
 Here are some examples: