diff --git a/llvm/utils/UpdateTestChecks/common.py b/llvm/utils/UpdateTestChecks/common.py
--- a/llvm/utils/UpdateTestChecks/common.py
+++ b/llvm/utils/UpdateTestChecks/common.py
@@ -273,7 +273,8 @@
 def add_ir_checks(output_lines, comment_marker, prefix_list, func_dict,
                   func_name, preserve_names):
   # Label format is based on IR string.
-  check_label_format = '{} %s-LABEL: @%s('.format(comment_marker)
+  function_def_regex = 'define {{[^@]+}}'
+  check_label_format = '{} %s-LABEL: {}@%s('.format(comment_marker, function_def_regex)
   add_checks(output_lines, comment_marker, prefix_list, func_dict, func_name,
              check_label_format, False, preserve_names)