Faster readRegexp (#13453)

packages/babel-parser/benchmark/large-regexp/bench.mjs

@@ -0,0 +1,22 @@
+import Benchmark from "benchmark";
+import baseline from "@babel-baseline/parser";
+import current from "../../lib/index.js";
+import { report } from "../util.mjs";
+
+const suite = new Benchmark.Suite();
+function createInput(length) {
+  return "const a = /" + "[/\\\\]".repeat(length / 4) + "/igsudm";
+}
+function benchCases(name, implementation, options) {
+  for (const length of [256, 512, 1024, 2048]) {
+    const input = createInput(length);
+    suite.add(`${name} ${length}-size RegExp literal `, () => {
+      implementation.parse(input, options);
+    });
+  }
+}
+
+benchCases("baseline", baseline);
+benchCases("current", current);
+
+suite.on("cycle", report).run();

packages/babel-parser/benchmark/many-small-all-flags-regexp/bench.mjs

@@ -0,0 +1,22 @@
+import Benchmark from "benchmark";
+import baseline from "../../lib/index-v2.js";
+import current from "../../lib/index.js";
+import { report } from "../util.mjs";
+
+const suite = new Benchmark.Suite();
+function createInput(length) {
+  return "/x/dgimsuy;".repeat(length);
+}
+function benchCases(name, implementation, options) {
+  for (const length of [256, 512, 1024, 2048]) {
+    const input = createInput(length);
+    suite.add(`${name} ${length} small regexp literal with all flags`, () => {
+      implementation.parse(input, options);
+    });
+  }
+}
+
+benchCases("baseline", baseline);
+benchCases("current", current);
+
+suite.on("cycle", report).run();