perry

First tagged release since v0.5.178 — 115 commits of accumulated work. Headline changes: generational mark-sweep GC and SSO are now default ON, JSON parsing went tape-based + lazy by default, Windows toolchain dropped its Visual Studio dependency, and Native UI grew end-to-end notification support on iOS + Android.

Highlights

• Generational mark-sweep GC default ON — Phases A-D land the shadow stack, write barriers, nursery/old-gen split, non-moving tenuring, copying evacuation pass, and per-cycle idle-block return-to-OS. PERRY_GEN_GC=0 reverts (bisection only). (v0.5.217 → v0.5.239)
• SSO (Small String Optimization) default ON — runtime infrastructure + codegen three-way PropertyGet branch + consumer arms behind PERRY_SSO_FORCE while baking, then default-flipped at v0.5.216. (v0.5.213 → v0.5.216)
• JSON parsing rebuilt — schema-directed JSON.parse<T>(blob), tape-based parse foundation, lazy parse + lazy stringify (default ON), per-element sparse materialization, walk-cursor + adaptive materialize threshold. (v0.5.200 → v0.5.210)
• Windows lightweight toolchain — winget LLVM + xwin, no Visual Studio needed (#176, v0.5.199); plus actionable clang-missing / link.exe error messages and perry doctor LLVM checks.
• visionOS simulator support — --target visionos-simulator (v0.5.185).

Performance

• JSON: lazy parse default ON (v0.5.210), per-element sparse materialization (v0.5.208), NEON/SSE2 string scanner (v0.5.197).
• GC: arena block size 8 MB → 1 MB (v0.5.196), trigger threshold 128 MB → 64 MB (v0.5.198), idle nursery blocks returned to OS (v0.5.235).
• Buffer.alloc fast-path via per-thread bump slab (#92, v0.5.190); BigInt arena alloc + BigInt(str) === fix (#92, v0.5.187); parseFloat zero-alloc + Infinity fix (#92).

Runtime / Codegen Fixes

• JSON: JSON.stringify of plain f64 segfaulted (v0.5.286); restore #[no_mangle] on js_json_stringify (v0.5.211).
• NaN: NaN==NaN + ECMAScript number formatting (v0.5.281); NaN/Infinity ToInt32 in (x) | 0 (v0.5.280); SSO + property-read NaN bug (v0.5.279).
• Promises: microtask FIFO + thrown-handler propagation (v0.5.284); Promise.all/race/any non-promise discrimination (v0.5.263); Promise.allSettled non-Promise values; queueMicrotask never running + performance.now() always 0 (#156, v0.5.180).
• Codegen: cross-module class getters/setters returned undefined (twice — c4739341, 2a088551); inline pass remaps closure captures (v0.5.273); don't inline functions with rest params (v0.5.278); i32 loop counter for number-typed bounds (#168, v0.5.188); js_try_end on return inside try body; FFI manifest consumption for native-library ABI; for-loop continue skipping update on --target web (#137).
• fs.readFileSync(path) returns Buffer when no encoding (v0.5.277); BigInt fromTwos/toTwos two's complement (v0.5.255); console.time resolution (#155, v0.5.181); Int32Array length=0 + Uint8ClampedArray no-clamp + negative NaN (#157, v0.5.184); isWellFormed/toWellFormed lone-surrogate detection (#29).
• WASM: drop excess args at WASM call sites (#183, v0.5.205).
• Type predicates + lazy audit (v0.5.212); HIR silent fall-throughs in lowerer + monomorph (v0.5.249).

Stdlib & Node Compat (#187 follow-ups)

• Redis (ioredis) end-to-end + dispatch-table-symbol-mismatch fix (v0.5.270); pg + mongo async-factory pattern (v0.5.275); AsyncLocalStorage end-to-end (v0.5.261); decimal.js (v0.5.259); commander runtime + codegen .action() invocation (v0.5.250); new T() bug on EE/LRU/WSS (v0.5.252); Buffer numeric reads intrinsified (#92, v0.5.183).
• Fastify end-to-end integration test + two dispatch fixes (#174, v0.5.189); mysql2 + pg connection.execute() param binding (#143, v0.5.182).

Native UI

• Apple (iOS / macOS): notificationSend (#94, ui-ios v0.5.193), client-side remote-push token + receive (#95, v0.5.243), scheduled + cancellable local notifications (#96, v0.5.244), notification tap callback (#97, v0.5.254).
• Android: notificationSend (#94, v0.5.256), schedule + cancel notifications (#96, v0.5.260), notification tap callback (#97, v0.5.258), FCM register + receive (#95, v0.5.262).

Platform / Toolchain

• Windows: lightweight toolchain (#176, v0.5.199); find_lld_link/find_perry_windows_sdk cfg gate hotfix (v0.5.201); /SUBSYSTEM:CONSOLE for non-UI PE builds (#120, v0.5.179); actionable clang/link.exe error messages (#176 follow-ups, v0.5.191/.192).
• npm: libc:glibc field on linux-x64 and linux-arm64 packages (#116/#161).

Documentation & Benchmarks

• Polyglot benchmark suite expansions: Kotlin + JSON polyglot (v0.5.241/.242), simdjson + AssemblyScript+json-as peers (v0.5.274), loop_data_dependent + bench_field_access landed (v0.5.272).
• Methodology hardening: RUNS=11 median + p95 + σ + macOS pinning (v0.5.248); 04_array_read 211 MB peak RSS explained (v0.5.276); FP-contract caveat (FMA-contract vs no-contract clustering) on bench_loop_data_dependent (v0.5.293).
• Node TS-strip leveling: json_polyglot/run.sh precompiles Node TS to .mjs as untimed setup so Node isn't charged for --experimental-strip-types runtime parse (v0.5.293).
• GC academic + industry lineage appendix; Phase D roadmap closeout (v0.5.239/.240).
• CLAUDE.md condense — 124 verbose Recent Changes entries (~242 KB) migrated to CHANGELOG.md, file went 254 KB → 12 KB (v0.5.292).

Repo & CI Hygiene

• chore(repo) v0.5.293: untrack 465 Android Gradle cache files, gitignore android-build/.gradle//build//app/build/, docs/examples/_reports/, external demo assets/, and stray repro binaries.
• CI macos-14 jobs no longer OOM on disk space (v0.5.289-.291).
• Memory stability suite for RSS-leak + GC-aggression regressions (v0.5.233).
• Stub-audit cleanups: test_json, test_gap_console_methods, test_gap_class_advanced removed from known_failures.json.

Escape Hatches

• PERRY_GEN_GC=0 — revert generational GC to full mark-sweep.
• PERRY_SHADOW_STACK=0 — disable shadow-stack precise roots.
• PERRY_GEN_GC_EVACUATE=1 — opt into copying evacuation (default OFF, work-saving on workloads where nothing tenures).
• PERRY_WRITE_BARRIERS=1 — opt into codegen-emitted write barriers (runtime barrier always exists).
• PERRY_GC_DIAG=1 — per-cycle GC diagnostics.