update_mir_test_checks.py: add a flag --use-first-common-prefix

[aemerson]

Summary

update_mir_test_checks.py: add a flag --use-first-common-prefix to use the first common prefix found for generating checks, instead of ignoring them.

[arsenm]

I don't think this should have an option. Ideally it would just be smart like update_llc_test_checks where it understands it expects identical output between the two cases

[aemerson]

In D105319#2854423, @arsenm wrote:

I don't think this should have an option. Ideally it would just be smart like update_llc_test_checks where it understands it expects identical output between the two cases

This makes it more convenient to at least update tests, and a final run of the tests will confirm if all the common checks were actually identical. Adding verification seems more work than I want to invest, so I'll leave it at that. I can also make it on by default too.

llvm/utils/update_mir_test_checks.py

 def find_triple_in_ir(lines, verbose=False):
     for l in lines:
         m = common.TRIPLE_IR_RE.match(l)
         if m:
             return m.group(1)
     return None
 
 
-def build_run_list(test, run_lines, verbose=False):
+def build_run_list(test, run_lines, args):
     run_list = []
     all_prefixes = []
     for l in run_lines:
         if '|' not in l:
             common.warn('Skipping unparseable RUN line: ' + l)
             continue
 
         commands = [cmd.strip() for cmd in l.split('|', 1)]
for l in run_lines:
             check_prefixes = ['CHECK']
         all_prefixes += check_prefixes
 
         run_list.append(Run(check_prefixes, cmd_args, triple))
 
     # Remove any common prefixes. We'll just leave those entirely alone.
     common_prefixes = set([prefix for prefix in all_prefixes
                            if all_prefixes.count(prefix) > 1])
+
+    # ...unless we're told to use the first one we see, ignoring the rest.
+    used_prefixes = set()
+    if args.use_first_common_prefix:
+        for run in run_list:
+            filtered_prefixes = []
+            for p in run.prefixes:
+                if p in common_prefixes:
+                    if p not in used_prefixes:
+                        filtered_prefixes.append(p)
+                        used_prefixes.add(p)
+                else:
+                    filtered_prefixes.append(p)
+        run.prefixes = filtered_prefixes
+    else:
         for run in run_list:
             run.prefixes = [p for p in run.prefixes if p not in common_prefixes]
 
     return run_list, common_prefixes
 
 
 def find_functions_with_one_bb(lines, verbose=False):
     result = []
     cur_func = None
     bbs = 0
def update_test_file(args, test):
 
     if args.update_only:
       if not first_line or 'autogenerated' not in first_line:
         common.warn("Skipping test which isn't autogenerated: " + test)
         return
 
     triple_in_ir = find_triple_in_ir(input_lines, args.verbose)
     run_lines = common.find_run_lines(test, input_lines)
-    run_list, common_prefixes = build_run_list(test, run_lines, args.verbose)
+    run_list, common_prefixes = build_run_list(test, run_lines, args)
 
     simple_functions = find_functions_with_one_bb(input_lines, args.verbose)
 
     func_dict = {}
     for run in run_list:
         for prefix in run.prefixes:
             func_dict.update({prefix: dict()})
     for prefixes, llc_args, triple_in_cmd in run_list:
def update_test_file(args, test):
 
     state = 'toplevel'
     func_name = None
     prefix_set = set([prefix for run in run_list for prefix in run.prefixes])
     log('Rewriting FileCheck prefixes: {}'.format(prefix_set), args.verbose)
 
     if args.remove_common_prefixes:
         prefix_set.update(common_prefixes)
-    elif common_prefixes:
+    elif common_prefixes and not args.use_first_common_prefix:
         common.warn('Ignoring common prefixes: {}'.format(common_prefixes),
              test_file=test)
 
     comment_char = '#' if test.endswith('.mir') else ';'
     autogenerated_note = ('{} NOTE: Assertions have been autogenerated by '
                           'utils/{}'.format(comment_char, script_name))
     output_lines = []
     output_lines.append(autogenerated_note)

 def main():
     parser = argparse.ArgumentParser(
         description=__doc__, formatter_class=argparse.RawTextHelpFormatter)
     parser.add_argument('--llc-binary', dest='llc', default='llc', type=LLC,
                         help='The "llc" binary to generate the test case with')
     parser.add_argument('--remove-common-prefixes', action='store_true',
                         help='Remove existing check lines whose prefixes are '
                              'shared between multiple commands')
+    parser.add_argument('--use-first-common-prefix', action='store_true',
+                        help='If there are common prefixes shared between run lines,'
+                        ' use the first one instead of ignoring them all')
     parser.add_argument('tests', nargs='+')
     args = common.parse_commandline_args(parser)
 
     test_paths = [test for pattern in args.tests for test in glob.glob(pattern)]
     for test in test_paths:
         try:
             update_test_file(args, test)
         except Exception:
             common.warn('Error processing file', test_file=test)
             raise
 
 
 if __name__ == '__main__':
   main()