Merge remote-tracking branch 'origin/perf/static-objects' into HEAD

# Conflicts:
#	packages/compiler/src/frontend/pipeline.ts
#	packages/compiler/src/frontend/shape-inference/overlay.ts
#	tests/harness/npm.test.ts

scripts/bench-runtime.mjs

@@ -180,6 +180,16 @@ function generateInput(kind) {
         ["sku-" + i, "category-" + (i % 17), "product " + i, i % 40, 199 + (i % 5000)].join("\t"),
       ).join("\n") + "\n",
     );
+  } else if (kind === "line-reader") {
+    // About 67 MB of access-log lines; every 50th path is not ASCII.
+    writeFileSync(
+      path,
+      Array.from(
+        { length: 600_000 },
+        (_, i) =>
+          `10.${i % 251}.${i % 7}.${i % 13} - - [24/Oct/2026:${String(i % 24).padStart(2, "0")}:${String(i % 60).padStart(2, "0")}:00 +0000] "${i % 9 === 0 ? "POST" : "GET"} /${i % 50 === 0 ? "caf\u00e9" : "api"}/items/${i % 997}?page=${i % 31} HTTP/1.1" ${i % 23 === 0 ? 404 : 200} ${(i * 7919) % 50000} "scriptc-bench/1.0"`,
+      ).join("\n") + "\n",
+    );
   } else if (kind === "cli-config") {
     writeFileSync(path, JSON.stringify(deployManifest(), null, 2) + "\n");
   } else throw new Error(`unknown input kind ${kind}`);

scripts/build-native-cli.mts

@@ -17,9 +17,16 @@ const sanitize = process.env["SCRIPTC_SAN"] === "1";
 // SCRIPTC_NATIVE_PROFILE_GENERATE=<pattern> builds a compiler that writes a
 // raw profile per run (scripts/refresh-cli-profile.mjs). Optimized builds
 // otherwise use the committed profile, or the indexed profile that
-// SCRIPTC_NATIVE_PROFILE_USE names; an empty SCRIPTC_NATIVE_PROFILE_USE
-// builds without one.
+// SCRIPTC_NATIVE_PROFILE_USE names (gzip-compressed when the name ends in
+// .gz, as refresh-cli-profile.mjs writes it); an empty
+// SCRIPTC_NATIVE_PROFILE_USE builds without one.
 const profileGenerate = process.env["SCRIPTC_NATIVE_PROFILE_GENERATE"] || undefined;
+// Below this share of matching functions, the build warns that the profile
+// has lost most of its gain. A profile refreshed on the same commit matched
+// 92.7% of the native compiler's profiled functions, one refreshed 1.5 days
+// and about 200 commits earlier 87.2%, and that one kept about half of the
+// fresh profile's gain on a cold tsc-ts build.
+const PROFILE_MATCH_WARNING = 0.9;
 const committedProfile = join(root, "packages/compiler/native/cli.profdata.gz");
 const requestedProfile = process.env["SCRIPTC_NATIVE_PROFILE_USE"];
 const useProfile =
@@ -45,10 +52,11 @@ const seed = join(dirname(output), ".scriptc", basename(output) + "-seed");
 for (const dir of [bin, lib, seed]) mkdirSync(dir, { recursive: true });
 let profileUse: string | undefined;
 if (useProfile) {
-  profileUse = requestedProfile;
-  if (profileUse === undefined) {
+  profileUse = requestedProfile ?? committedProfile;
+  if (profileUse.endsWith(".gz")) {
+    const compressed = profileUse;
     profileUse = join(seed, "cli.profdata");
-    writeFileSync(profileUse, gunzipSync(readFileSync(committedProfile)));
+    writeFileSync(profileUse, gunzipSync(readFileSync(compressed)));
   }
 }
 const compiler = process.env["SCRIPTC_CC"] ?? target.defaultLinker;
@@ -127,6 +135,25 @@ if (!result.ok)
       )
       .join("\n"),
   );
+// How well the profile still describes the compiler: a function whose
+// control flow changed since the profile was collected is optimized as
+// without one. The share falls as compiler code changes, and with it the
+// profile's gain (refresh it with scripts/refresh-cli-profile.mjs).
+const match = useProfile && "artifact" in result ? result.artifact.profileMatch : undefined;
+if (match !== undefined) {
+  const profiled = match.annotated + match.mismatched;
+  const share = profiled === 0 ? 0 : match.annotated / profiled;
+  console.log(
+    `native compiler profile: ${match.annotated} of ${profiled} profiled functions match (${(100 * share).toFixed(1)}%); ${match.missing} functions have no profile` +
+      (match.unknownPartitions > 0
+        ? `; ${match.unknownPartitions} partitions reused without counts`
+        : ""),
+  );
+  if (match.unknownPartitions === 0 && share < PROFILE_MATCH_WARNING)
+    console.warn(
+      `warning: the native compiler profile matches ${(100 * share).toFixed(1)}% of the functions it describes; run scripts/refresh-cli-profile.mjs`,
+    );
+}
 const compilerVersion = (
   JSON.parse(readFileSync(join(root, "packages/compiler/package.json"), "utf8")) as {
     version: string;

scripts/refresh-cli-profile.mjs

@@ -1,6 +1,8 @@
 #!/usr/bin/env node
-/* Refreshes packages/compiler/native/cli.profdata.gz, the profile that release
- * builds of the native compiler optimize with (scripts/build-native-cli.mts).
+/* Refreshes packages/compiler/native/cli.profdata.gz, the profile that builds
+ * of the native compiler optimize with (scripts/build-native-cli.mts). The
+ * release workflow's cli-profile job runs it with --output on the release
+ * commit, and release builds use that profile instead of the committed one.
  *
  * Builds an instrumented native compiler for this Linux host, runs it on the
  * training builds below, and merges the raw profiles it writes into one
@@ -26,7 +28,7 @@ import {
   writeFileSync,
 } from "node:fs";
 import { cpus, tmpdir } from "node:os";
-import { join, resolve } from "node:path";
+import { dirname, join, resolve } from "node:path";
 import { fileURLToPath } from "node:url";
 import { parseArgs } from "node:util";
 import { constants, gzipSync } from "node:zlib";
@@ -55,6 +57,9 @@ const tscTsPackage = join(tscTs, "packages/tsc-ts");
 if (!existsSync(join(tscTsPackage, "src/main.ts")))
   throw new Error(`${tscTs} is not a tsc-ts checkout with installed dependencies`);
 const jobs = Number(values.jobs);
+// The output's directory is created up front, before the instrumented build.
+const profileOutput = resolve(values.output);
+mkdirSync(dirname(profileOutput), { recursive: true });
 const work = resolve(values.work ?? mkdtempSync(join(tmpdir(), "scriptc-cli-profile-")));
 const raw = join(work, "raw");
 const builds = join(work, "builds");
@@ -196,10 +201,12 @@ const merged = spawnSync(scriptc, ["merge-profiles", "--sparse", "-o", indexed,
 });
 if (merged.status !== 0) throw new Error("merge-profiles failed");
 // The indexed profile compresses to about an eighth of its size.
-const output = resolve(values.output);
-writeFileSync(output, gzipSync(readFileSync(indexed), { level: constants.Z_BEST_COMPRESSION }));
+writeFileSync(
+  profileOutput,
+  gzipSync(readFileSync(indexed), { level: constants.Z_BEST_COMPRESSION }),
+);
 console.log(
-  `wrote ${output} (${statSync(output).size} bytes; ${statSync(indexed).size} uncompressed)`,
+  `wrote ${profileOutput} (${statSync(profileOutput).size} bytes; ${statSync(indexed).size} uncompressed)`,
 );
 // A work directory the caller named stays for inspection.
 if (values.work === undefined) rmSync(work, { recursive: true, force: true });

scripts/zero-cost-compare.mjs

@@ -395,7 +395,9 @@ export function dynamicTierSymbols(names) {
  * bench/channel-messages and bench/worker-messages, added later, link them
  * through worker messages:
  * node:worker_threads values are dyn objects. bench/json-unions, added
- * later too, decodes JSON.parse trees. bench/dynamic-methods and
+ * later too, decodes JSON.parse trees. bench/throw-chains, also added
+ * later, tests caught values with `instanceof`, as bench/validate-errors
+ * does. bench/dynamic-methods and
  * bench/dynamic-properties are untyped JavaScript. Every other bench workload is fully typed and must link none. The gate and
  * tests/harness/bench-dynamic-tier.test.ts enforce that, and the test also
  * fails when a listed workload stops linking them, so remove a workload here
@@ -416,7 +418,9 @@ export const DYNAMIC_WORKLOADS = new Set([
   "bench/typed-array-scan-workers",
   "bench/log-summary",
   "bench/inventory-report",
+  "bench/line-reader",
   "bench/json-unions",
+  "bench/throw-chains",
 ]);
 
 /** Names of the functions (text and weak symbols) in `nm` output. Mach-O