tests/run-internalbench.py: Add option for running against CPython.

AJMansfield · dpgeorge · commit 8a1f050771c0 · 2026-03-03T23:25:36.000+11:00
Occasionally, it's useful to be able to compare MicroPython's performance
figures to CPython's. This change adds the ability to run the internalbench
test runner with `--test-instance=cpython` in order to execute the same
test routines against CPython and produce a benchmark performance report in
the same format as MicroPython.

Signed-off-by: Anson Mansfield &lt;amansfield@mantaro.com&gt;
diff --git a/tests/run-internalbench.py b/tests/run-internalbench.py
@@ -21,8 +21,14 @@
     MICROPYTHON = os.getenv(
         "MICROPY_MICROPYTHON", "../ports/windows/build-standard/micropython.exe"
     )
+    CPYTHON3 = os.getenv("MICROPY_CPYTHON3", "python3")
 else:
     MICROPYTHON = os.getenv("MICROPY_MICROPYTHON", "../ports/unix/build-standard/micropython")
+    CPYTHON3 = os.getenv("MICROPY_CPYTHON3", "python3")
+
+MICROPYTHON_CMD = [MICROPYTHON, "-X", "emit=bytecode"]
+CPYTHON3_CMD = [CPYTHON3, "-BS"]
+
 
 injected_bench_code = b"""
 import time
@@ -43,14 +49,14 @@ def run(test):
 """
 
 
-def execbench(pyb, filename, iters):
+def execbench(test_instance, filename, iters):
     with open(filename, "rb") as f:
         pyfile = f.read()
     code = (injected_bench_code + pyfile).replace(b"20000000", str(iters).encode("utf-8"))
-    return pyb.exec(code).replace(b"\r\n", b"\n")
+    return test_instance.exec(code).replace(b"\r\n", b"\n")
 
 
-def run_tests(pyb, test_dict, iters):
+def run_tests(test_instance, test_dict, iters):
     test_count = 0
     testcase_count = 0
 
@@ -59,19 +65,17 @@ def run_tests(pyb, test_dict, iters):
         baseline = None
         for test_file in tests:
             # run MicroPython
-            if pyb is None:
+            if isinstance(test_instance, list):
                 # run on PC
                 try:
-                    output_mupy = subprocess.check_output(
-                        [MICROPYTHON, "-X", "emit=bytecode", test_file[0]]
-                    )
+                    output_mupy = subprocess.check_output(test_instance + [test_file[0]])
                 except subprocess.CalledProcessError:
                     output_mupy = b"CRASH"
             else:
                 # run on pyboard
-                pyb.enter_raw_repl()
+                test_instance.enter_raw_repl()
                 try:
-                    output_mupy = execbench(pyb, test_file[0], iters)
+                    output_mupy = execbench(test_instance, test_file[0], iters)
                 except pyboard.PyboardError:
                     output_mupy = b"CRASH"
 
@@ -105,7 +109,7 @@ def main():
 {test_instance_description}
 {test_directory_description}
 """,
-        epilog=test_instance_epilog,
+        epilog=f"""{test_instance_epilog}- cpython - use CPython to run the benchmarks instead\n""",
     )
     cmd_parser.add_argument(
         "-t", "--test-instance", default="unix", help="the MicroPython instance to test"
@@ -128,8 +132,15 @@ def main():
     cmd_parser.add_argument("files", nargs="*", help="input test files")
     args = cmd_parser.parse_args()
 
-    # Note pyboard support is copied over from run-tests.py, not tests, and likely needs revamping
-    pyb = get_test_instance(args.test_instance, args.baudrate, args.user, args.password)
+    if args.test_instance == "cpython":
+        test_instance = CPYTHON3_CMD
+    else:
+        # Note pyboard support is copied over from run-tests.py, not tests, and likely needs revamping
+        test_instance = get_test_instance(
+            args.test_instance, args.baudrate, args.user, args.password
+        )
+        if test_instance is None:
+            test_instance = MICROPYTHON_CMD
 
     if len(args.files) == 0:
         if args.test_dirs:
@@ -153,7 +164,7 @@ def main():
             continue
         test_dict[m.group(1)].append([t, None])
 
-    if not run_tests(pyb, test_dict, args.iters):
+    if not run_tests(test_instance, test_dict, args.iters):
         sys.exit(1)
 
 
