[NFC][CI] Add check for python formatting, run black (#940)

Before pushing PRs with changes to python files, please run `black .` in
the directory with the changed python files (you might need to install
black).

Black formatter: https://pypi.org/project/black/

.github/workflows/black.yml

@@ -0,0 +1,12 @@
+name: Lint
+
+on: [push, pull_request]
+
+jobs:
+  lint:
+    runs-on: nod-ai-shared-cpubuilder-manylinux-x86_64
+    steps:
+      - uses: actions/checkout@v4
+      - uses: psf/black@stable
+
+# see https://black.readthedocs.io/en/stable/integrations/github_actions.html

build_tools/ci/cpu_comparison/run.py

@@ -103,10 +103,10 @@ def run(self, config):
             return False
 
         # If use_chess=1, and config has not provided a valid
-        # path to vitis, then don't run the test. The asymmetry between 
-        # logic for peano and chess is because we don't expect everyone 
+        # path to vitis, then don't run the test. The asymmetry between
+        # logic for peano and chess is because we don't expect everyone
         # running this script to have chess (currently Windows CI for example
-        # does not). 
+        # does not).
         if self.use_chess and not config.vitis_dir:
             return False
 
@@ -115,7 +115,6 @@ def run(self, config):
         if not self.use_chess and not config.peano_dir:
             raise RuntimeError("Peano path not provided, and use_chess=False")
 
-
         # Call into test-specific code to run the test.
         return self._execute(config)
 
@@ -366,7 +365,9 @@ class MatmulBenchmark(BaseMatmul):
     A test of the form matmul(A,B) where A:MxK, B:KxN
     """
 
-    benchmark_compilation_flags = ["--iree-amdaie-enable-infinite-loop-around-core-block=true"]
+    benchmark_compilation_flags = [
+        "--iree-amdaie-enable-infinite-loop-around-core-block=true"
+    ]
 
     def __init__(
         self,
@@ -750,7 +751,9 @@ def generate_aie_output(config, aie_vmfb, input_args, function_name, name, outpu
     return np_from_binfile(aie_bin, output_type)
 
 
-def benchmark_aie_kernel_time(config, aie_vmfb, input_args, function_name, name, n_repeats, n_kernel_runs):
+def benchmark_aie_kernel_time(
+    config, aie_vmfb, input_args, function_name, name, n_repeats, n_kernel_runs
+):
     """
     Benchmark a compiled AIE module's (aie_vmfb) kernel time, average over the specified number of runs.
     """
@@ -1131,7 +1134,7 @@ def benchmark_aie(
     lower_to_aie_pipeline:
         The pipeline to be used for lowering to AIE (objectFifo, AIR).
     n_repeats:
-        The number of repetitions to be used for getting statistics (mean, median, stddev) 
+        The number of repetitions to be used for getting statistics (mean, median, stddev)
     n_kernel_runs:
         The number of invocations of the kernel, for averaging.
     function_name:
@@ -1141,12 +1144,14 @@ def benchmark_aie(
         The seed to be used for generating the inputs.
     """
     if (
-        "--iree-amdaie-enable-infinite-loop-around-core-block=true" 
+        "--iree-amdaie-enable-infinite-loop-around-core-block=true"
         not in aie_compilation_flags
     ):
-        raise ValueError("To benchmark an AIE kernel module, the " \
-            "`--iree-amdaie-enable-infinite-loop-around-core-block=true` " \
-            "should be passed.")
+        raise ValueError(
+            "To benchmark an AIE kernel module, the "
+            "`--iree-amdaie-enable-infinite-loop-around-core-block=true` "
+            "should be passed."
+        )
 
     name = name_from_mlir_filename(test_file)
     input_args = generate_inputs(test_file, config.output_dir, seed)
@@ -1167,7 +1172,7 @@ def benchmark_aie(
         if config.verbose:
             print(f"Skipping AIE run for {test_file} because 'do_not_run_aie=True'.")
         return
-    
+
     print(f"Performance benchmark: {test_file}")
     benchmark_aie_kernel_time(
         config,
@@ -1350,8 +1355,6 @@ def __init__(self):
             )
         )
 
-
-
         # Some bf16 Performance tests:
         for M, N, K, use_ukernel in [
             (512, 512, 4096, False),
@@ -1571,9 +1574,8 @@ def all_tests(
 
     for test in tests.tests:
 
-        skip = (
-            test.name in skip_test_set or
-            any((label in skip_test_set for label in test.labels))
+        skip = test.name in skip_test_set or any(
+            (label in skip_test_set for label in test.labels)
         )
         if skip:
             not_match.append(test.name)