Add JIT compilation speed benchmark

Summary:
Add a benchmark that measures JIT compilation time (not runtime performance of generated code). It collects functions from the existing benchmark modules, force-compiles each one, and reports per-function and aggregate timing in microseconds.

Run with: buck run //cinderx/benchmarks:compile-time

Reviewed By: alexmalyshev

Differential Revision: D98906989

fbshipit-source-id: 7182476a84026f1acdf534ef870a1ddf2b22c8c8

Author: kddnewton

cinderx/benchmarks/compile_time.py

@@ -0,0 +1,68 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+
+# pyre-strict
+
+"""
+JIT compilation speed benchmark.
+
+Measures how long it takes the CinderX JIT to compile functions, not the
+runtime performance of the generated code. Uses compile_after_n_calls(0) to
+eagerly compile all functions on import, then reports per-function and
+aggregate timing statistics.
+
+Usage:
+    buck run //cinderx/benchmarks:compile-time
+
+For a per-phase breakdown of each function's compilation, pass the jit-time
+flag via Python's -X option:
+    buck run //cinderx/benchmarks:compile-time -- -X jit-time='*'
+"""
+
+from __future__ import annotations
+
+import logging
+
+import cinderx.jit
+
+logger: logging.Logger = logging.getLogger(__name__)
+
+
+def main() -> None:
+    cinderx.jit.compile_after_n_calls(0)
+
+    # Importing these modules triggers JIT compilation of all their functions.
+    # These are bundled via srcs in the BUCK target, not as separate deps.
+    from cinderx.benchmarks import (  # noqa: F811  # @manual
+        binary_trees,
+        fannkuch,
+        nbody,
+        richards,
+        spectral_norm,
+    )
+
+    # Suppress unused import warnings.
+    _ = (binary_trees, fannkuch, nbody, richards, spectral_norm)
+
+    cinderx.jit.disable()
+
+    results: list[tuple[str, float]] = []
+    for func in cinderx.jit.get_compiled_functions():
+        comp_time = cinderx.jit.get_function_compilation_time(func)
+        name = f"{func.__module__}:{func.__qualname__}"
+        results.append((name, comp_time))
+
+    results.sort(key=lambda r: r[1], reverse=True)
+
+    print(f"{'Function':<60} {'Time (ms)':>10}")
+    print("-" * 71)
+    for name, t in results:
+        print(f"{name:<60} {t:>10.3f}")
+
+    total = sum(t for _, t in results)
+    print("-" * 71)
+    print(f"{'Total':<60} {total:>10.3f}")
+    print(f"{'Functions compiled':<60} {len(results):>10}")
+
+
+if __name__ == "__main__":
+    main()