Add note about afn

MacDue · MacDue · commit 9fdf9fb1aa10 · 2024-10-02T14:12:32.000Z
diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
@@ -15842,6 +15842,9 @@ and :ref:`llvm.cos <t_llvm_cos>` on the argument.
 The first result is the sine of the argument and the second result is the cosine
 of the argument.
 
+When specified with the fast-math-flag 'afn', the result may be approximated
+using a less accurate calculation.
+
 '``llvm.pow.*``' Intrinsic
 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
