diff --git a/llvm/utils/update_llc_test_checks.py b/llvm/utils/update_llc_test_checks.py
--- a/llvm/utils/update_llc_test_checks.py
+++ b/llvm/utils/update_llc_test_checks.py
@@ -20,11 +20,13 @@
 from UpdateTestChecks import asm, common
 
 ADVERT = ' NOTE: Assertions have been autogenerated by '
-
+# llc is the only llc-like in the LLVM tree but downstream forks can add
+# additional ones here if they have them.
+LLC_LIKE_TOOLS = ('llc',) 
 
 def main():
   parser = argparse.ArgumentParser(description=__doc__)
-  parser.add_argument('--llc-binary', default='llc',
+  parser.add_argument('--llc-binary', default=None,
                       help='The "llc" binary to use to generate the test case')
   parser.add_argument(
       '--function', help='The function in the test file to update')
@@ -91,7 +93,7 @@
       if len(commands) > 1:
         filecheck_cmd = commands[1]
       common.verify_filecheck_prefixes(filecheck_cmd)
-      if llc_tool != 'llc':
+      if llc_tool not in LLC_LIKE_TOOLS:
         common.warn('Skipping non-llc RUN line: ' + l)
         continue
 
@@ -129,7 +131,8 @@
       common.debug('Extracted LLC cmd:', llc_tool, llc_args)
       common.debug('Extracted FileCheck prefixes:', str(prefixes))
 
-      raw_tool_output = common.invoke_tool(args.llc_binary, llc_args, test)
+      raw_tool_output = common.invoke_tool(args.llc_binary or llc_tool,
+                                           llc_args, test)
       triple = triple_in_cmd or triple_in_ir
       if not triple:
         triple = asm.get_triple_from_march(march_in_cmd)