From bd1438e4dbec0acc6f268805568449f347b535c8 Mon Sep 17 00:00:00 2001
From: ghangz <152254226+ghangz@users.noreply.github.com>
Date: Wed, 1 Jul 2026 11:39:26 +0800
Subject: [PATCH 1/2] Add mxcc compile performance gate

---
 tools/mxcc_perf_gate.py | 58 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 tools/mxcc_perf_gate.py

diff --git a/tools/mxcc_perf_gate.py b/tools/mxcc_perf_gate.py
new file mode 100644
index 000000000000..aed125a7d159
--- /dev/null
+++ b/tools/mxcc_perf_gate.py
@@ -0,0 +1,58 @@
+#!/usr/bin/env python3
+"""Compare baseline and current performance JSON and fail on regressions."""
+
+from __future__ import annotations
+
+import argparse
+import json
+from pathlib import Path
+
+METRIC = 'compile_seconds'
+TOLERANCE = 0.1
+
+
+def load(path: Path) -> dict[str, float]:
+    data = json.loads(path.read_text(encoding="utf-8"))
+    if isinstance(data, list):
+        return {str(item["name"]): float(item[METRIC]) for item in data}
+    return {str(k): float(v[METRIC] if isinstance(v, dict) else v) for k, v in data.items()}
+
+
+def compare(baseline: dict[str, float], current: dict[str, float]) -> dict[str, object]:
+    rows: list[dict[str, object]] = []
+    failed = False
+    for name, old in sorted(baseline.items()):
+        if name not in current:
+            rows.append({"name": name, "status": "missing-current"})
+            failed = True
+            continue
+        new = current[name]
+        ratio = (new - old) / old if old else 0.0
+        status = "regression" if ratio < -TOLERANCE else "ok"
+        failed = failed or status != "ok"
+        rows.append({"name": name, "baseline": old, "current": new, "delta_ratio": ratio, "status": status})
+    return {"ok": not failed, "metric": METRIC, "rows": rows}
+
+
+def self_test() -> None:
+    data = compare({"case": 100.0}, {"case": 99.0})
+    assert data["ok"]
+    print(json.dumps({"ok": True, "rows": len(data["rows"])}, ensure_ascii=False))
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("baseline")
+    parser.add_argument("current")
+    parser.add_argument("--self-test", action="store_true")
+    args = parser.parse_args()
+    if args.self_test:
+        self_test()
+        return 0
+    result = compare(load(Path(args.baseline)), load(Path(args.current)))
+    print(json.dumps(result, ensure_ascii=False, indent=2))
+    return 0 if result["ok"] else 1
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

From 1ce3a7ff386a7cc83fdd02643b45dca3086fe9e1 Mon Sep 17 00:00:00 2001
From: ghangz <152254226+ghangz@users.noreply.github.com>
Date: Wed, 1 Jul 2026 15:04:23 +0800
Subject: [PATCH 2/2] Fix mxcc compile time regression direction

---
 tools/mxcc_perf_gate.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/tools/mxcc_perf_gate.py b/tools/mxcc_perf_gate.py
index aed125a7d159..19b1bbef54a5 100644
--- a/tools/mxcc_perf_gate.py
+++ b/tools/mxcc_perf_gate.py
@@ -28,7 +28,7 @@ def compare(baseline: dict[str, float], current: dict[str, float]) -> dict[str,
             continue
         new = current[name]
         ratio = (new - old) / old if old else 0.0
-        status = "regression" if ratio < -TOLERANCE else "ok"
+        status = "regression" if ratio > TOLERANCE else "ok"
         failed = failed or status != "ok"
         rows.append({"name": name, "baseline": old, "current": new, "delta_ratio": ratio, "status": status})
     return {"ok": not failed, "metric": METRIC, "rows": rows}
@@ -36,7 +36,11 @@ def compare(baseline: dict[str, float], current: dict[str, float]) -> dict[str,
 
 def self_test() -> None:
     data = compare({"case": 100.0}, {"case": 99.0})
-    assert data["ok"]
+    if not data["ok"]:
+        raise RuntimeError("self-test failed: faster compile time should pass")
+    regression = compare({"case": 100.0}, {"case": 120.0})
+    if regression["ok"]:
+        raise RuntimeError("self-test failed: slower compile time should regress")
     print(json.dumps({"ok": True, "rows": len(data["rows"])}, ensure_ascii=False))