feat: manually call v8 to optimize functions

Author: art049

packages/benchmark.js/src/index.ts

@@ -1,5 +1,5 @@
 import Benchmark from "benchmark";
-import measurement from "@codspeed/core";
+import { initCore, measurement, optimizeFunctionSync } from "@codspeed/core";
 import { get as getStackTrace } from "stack-trace";
 import path, { dirname } from "path";
 import { findUpSync, Options } from "find-up";
@@ -18,12 +18,15 @@ function withCodSpeedBenchmark(bench: Benchmark): Benchmark {
   if (!measurement.isInstrumented()) {
     return bench;
   }
+  initCore();
   const callingFile = getCallingFile();
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
   bench.run = function (options?: Benchmark.Options): Benchmark {
     const uri = callingFile + "::" + (bench.name ?? "unknown");
+    const fn = bench.fn as CallableFunction;
+    optimizeFunctionSync(fn);
     measurement.startInstrumentation();
-    (bench.fn as CallableFunction)();
+    fn();
     measurement.stopInstrumentation(uri);
     return bench;
   };

packages/core/src/index.ts

@@ -26,5 +26,25 @@ try {
     isBound: false,
   };
 }
-const measurement = m;
-export default measurement;
+export const measurement = m;
+
+export const initCore = () => {
+  // eslint-disable-next-line @typescript-eslint/no-var-requires
+  require("v8").setFlagsFromString("--allow-natives-syntax");
+};
+
+export const optimizeFunction = async (fn: CallableFunction) => {
+  // Source: https://github.com/petkaantonov/bluebird/wiki/Optimization-killers#optimization-killers
+  await fn(); //Fill type-info
+  await fn(); // 2 calls are needed to go from uninitialized -> pre-monomorphic -> monomorphic
+  eval("%OptimizeFunctionOnNextCall(fn)");
+  await fn(); // optimize
+};
+
+export const optimizeFunctionSync = (fn: CallableFunction) => {
+  // Source: https://github.com/petkaantonov/bluebird/wiki/Optimization-killers#optimization-killers
+  fn(); //Fill type-info
+  fn(); // 2 calls are needed to go from uninitialized -> pre-monomorphic -> monomorphic
+  eval("%OptimizeFunctionOnNextCall(fn)");
+  fn(); // optimize
+};

packages/tinybench/src/index.ts

@@ -1,4 +1,4 @@
-import measurement from "@codspeed/core";
+import { initCore, measurement, optimizeFunction } from "@codspeed/core";
 import { get as getStackTrace } from "stack-trace";
 import path, { dirname } from "path";
 import { findUpSync, Options } from "find-up";
@@ -8,11 +8,12 @@ export function withCodSpeed(bench: Bench): Bench {
   if (!measurement.isInstrumented()) {
     return bench;
   }
+  initCore();
   const callingFile = getCallingFile();
   bench.run = async () => {
     for (const task of bench.tasks) {
       const uri = callingFile + "::" + task.name;
-      await task.warmup();
+      await optimizeFunction(task.fn);
       measurement.startInstrumentation();
       await task.fn();
       measurement.stopInstrumentation(uri);