3 files changed, 61 insertions, 1 deletions
diff --git a/Lib/test/libregrtest/cmdline.py b/Lib/test/libregrtest/cmdline.py
index 9f1bf68..c8fedc7 100644
--- a/Lib/test/libregrtest/cmdline.py
+++ b/Lib/test/libregrtest/cmdline.py
@@ -264,7 +264,9 @@ def _create_parser():
                        help='only write the name of test cases that will be run'
                             ' , don\'t execute them')
     group.add_argument('-P', '--pgo', dest='pgo', action='store_true',
-                       help='enable Profile Guided Optimization training')
+                       help='enable Profile Guided Optimization (PGO) training')
+    group.add_argument('--pgo-extended', action='store_true',
+                       help='enable extended PGO training (slower training)')
     group.add_argument('--fail-env-changed', action='store_true',
                        help='if a test file alters the environment, mark '
                             'the test as failed')
@@ -344,6 +346,8 @@ def _parse_args(args, **kwargs):
         parser.error("-G/--failfast needs either -v or -W")
     if ns.pgo and (ns.verbose or ns.verbose2 or ns.verbose3):
         parser.error("--pgo/-v don't go together!")
+    if ns.pgo_extended:
+        ns.pgo = True  # pgo_extended implies pgo
 
     if ns.nowindows:
         print("Warning: the --nowindows (-n) option is deprecated. "
diff --git a/Lib/test/libregrtest/main.py b/Lib/test/libregrtest/main.py
index e227425..78b6790 100644
--- a/Lib/test/libregrtest/main.py
+++ b/Lib/test/libregrtest/main.py
@@ -17,6 +17,7 @@ from test.libregrtest.runtest import (
     INTERRUPTED, CHILD_ERROR, TEST_DID_NOT_RUN,
     PROGRESS_MIN_TIME, format_test_result, is_failed)
 from test.libregrtest.setup import setup_tests
+from test.libregrtest.pgo import setup_pgo_tests
 from test.libregrtest.utils import removepy, count, format_duration, printlist
 from test import support
 
@@ -214,6 +215,9 @@ class Regrtest:
 
         removepy(self.tests)
 
+        # add default PGO tests if no tests are specified
+        setup_pgo_tests(self.ns)
+
         stdtests = STDTESTS[:]
         nottests = NOTTESTS.copy()
         if self.ns.exclude:
diff --git a/Lib/test/libregrtest/pgo.py b/Lib/test/libregrtest/pgo.py
new file mode 100644
index 0000000..327f193
--- /dev/null
+++ b/Lib/test/libregrtest/pgo.py
@@ -0,0 +1,52 @@
+# Set of tests run by default if --pgo is specified.  The tests below were
+# chosen based on the following criteria: either they exercise a commonly used
+# C extension module or type, or they run some relatively typical Python code.
+# Long running tests should be avoided because the PGO instrumented executable
+# runs slowly.
+PGO_TESTS = [
+    'test_array',
+    'test_base64',
+    'test_binascii',
+    'test_binop',
+    'test_bisect',
+    'test_bytes',
+    'test_cmath',
+    'test_codecs',
+    'test_collections',
+    'test_complex',
+    'test_dataclasses',
+    'test_datetime',
+    'test_decimal',
+    'test_difflib',
+    'test_embed',
+    'test_float',
+    'test_fstring',
+    'test_functools',
+    'test_generators',
+    'test_hashlib',
+    'test_heapq',
+    'test_int',
+    'test_itertools',
+    'test_json',
+    'test_long',
+    'test_math',
+    'test_memoryview',
+    'test_operator',
+    'test_ordered_dict',
+    'test_pickle',
+    'test_pprint',
+    'test_re',
+    'test_set',
+    'test_statistics',
+    'test_struct',
+    'test_tabnanny',
+    'test_time',
+    'test_unicode',
+    'test_xml_etree',
+    'test_xml_etree_c',
+]
+
+def setup_pgo_tests(ns):
+    if not ns.args and not ns.pgo_extended:
+        # run default set of tests for PGO training
+        ns.args = PGO_TESTS[:]