A program is nondeterministic only when every artifact that differs also
differs between two baseline builds; a deterministic difference in another
artifact still fails the gate. The runtime-only check now reads the symbols
of changed vendor archives as well as runtime objects.
Main moved the per-program report lines into zero-cost-compare.mjs and
added sharding and a baseline cache. The runtime-only and
nondeterministic verdicts now print through programLines, count as
compared in merged shard reports, and the runtime pack diff is skipped
when only recording a baseline cache.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Linux links use ld.lld when clang finds it and the system linker
otherwise, and the two produce different executables. A baseline record
made with one must not settle candidates linked with the other.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A recorded baseline entry now holds a hash of its program's inputs: the
entry file and its relative imports (paths and contents) and the
optimization level. --baseline-cache uses an entry only when the program
still hashes the same, so a program or an import that changed since the
record builds its baseline, instead of a recorded build error or artifact
hash of the old sources settling the comparison as both-fail or identical.
Records take schema 2; older records are ignored.
The full gate takes 30 to 75 minutes on one Sandbox, which made it the
longest step of a validation round. It can now be split and merged:
- --shard=i/n splits the bench and corpus programs (the self-hosted
compiler runs in shard 1, or alone with --set=self), and
scripts/zero-cost-merge.mjs merges the shards' --json reports into one
verdict, recomputing the compile-time intervals over every shard.
- --record-baseline-cache records the baseline's artifact hashes once;
--baseline-cache skips the baseline build of every program whose
candidate artifacts hash the same. The record is tied to the built
baseline checkout, toolchain and paths.
- The candidate-source self build overlaps the comparison builds on
hosts with room for it.
pnpm test:sandbox can reuse a prepared snapshot's LLVM helper and runtime
pack (SCRIPTC_SANDBOX_NATIVE_REFERENCE) when their inputs are identical,
and retries rate-limited Sandbox creation with backoff.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The self program compiles the compiler source of the checkout the programs
come from (the baseline by default), so a change adding compiler code the
self-hosted frontend cannot lower passed the gate and failed CI's
self-hosting tests. With the self set, the gate now also builds the
candidate's packages/compiler/src/native/cli.ts with the candidate (LLVM
only, not compared) and fails when that build fails.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Any change to the runtime's C sources makes every executable differ, so
the gate failed even when every program's IR and LLVM were byte-identical.
The gate now classifies each difference outside --allow:
- runtime-only: IR and LLVM identical, the same LLVM helper, runtime pack
objects that differ between the checkouts (bitcode alone records the
checkout path, so it does not count), and every symbol the executable
gains, loses or resizes defined by a changed runtime object. It passes
with a note that lists the changed runtime functions the program links
(from the release and speed bitcode, through llvm-dis) and the size
change.
- nondeterministic: the baseline builds the program again, and its two
builds differ in the same artifacts. It passes with a note.
- differs: anything else; it fails as before.
--strict fails runtime-only and nondeterministic programs too.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Scope-B milestone NI-1, runtime side. Programs whose IR has a
`nodeIsland.*` operation link scr_node_island.c and the SCR_NODE_ISLANDS
build of scr_async.c; every other program links neither, byte for byte.
- scr_node_island.c dlopens the bridge of a libnode pack on the first call
(RTLD_NOW | RTLD_GLOBAL), checks its bridge ABI and that it links exactly
the Node version recorded at build time, starts one Node environment and
runs the embedded bootstrap (scr_node_island_host.cjs). A run that never
calls into Node never maps libnode. The pack directory is SCRIPTC_LIBNODE
at run time, else the recorded path; a `$ORIGIN/` path resolves against
the executable's directory (the beside packaging, and the hook for
shipping Node with the program).
- scr_node_bridge.h is the C ABI between the runtime and the bridge; the
runtime includes no Node or V8 header. The bridge
(packages/libnode-common/bridge/scr_node_bridge.cc) initializes Node once
with no default signal handling, no debug-signal handler or inspector,
no stdio reinitialization and one platform worker, creates the
environment from the built-in snapshot, routes Node's process exit to
the runtime's exit sequence, promotes libnode to the global scope for
native addons, and runs calls in a CallbackScope with a TryCatch.
build-pack.mjs assembles a pack (libnode, the bridge, manifest.json) from
a Node --shared build and the matching headers.
- The SCR_NODE_ISLANDS build of scr_async.c adds a loop slot through which
the runtime's loop drives Node's until NI-3 hosts the runtime's queues on
Node's libuv: it keeps the program alive while Node has ref'd work,
sleeps on Node's backend fd up to its next timer, and runs one
non-blocking turn per loop turn.
- The `nodeIsland` runtime feature (rule, link features, unit table, pack
matrix row and scr_async.c variant), the nodeIsland.call/callSync
libCalls, the install call in main, and the build-time record of the
pack (node-islands/libnode.ts: --libnode=<pack>|beside or
SCRIPTC_LIBNODE, SC8005 when none is usable, Node >=24.13.1).
- The zero-cost gate and the bench nm test require that no good-code
executable defines a Node island symbol.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A benchmark workload or the self-hosted compiler that fails to build
with both checkouts now fails the gate, and so does a run in which no
program built with both. Before this, a run whose builds all failed the
same way, such as with a helper of another version, reported PASS. A
build error now prints in full under its program; its first line is
often a warning.
workloads.json listed every workload in one array, and its README table
listed them in one hand order, so changes that each added a workload
appended at the same place and conflicted. Each workload is now a JSON
file in benchmarks/runtime/workloads/ named after it, read through
benchmarks/runtime/workloads.mjs by the bench runner, the zero-cost
gate, the strace script and the dynamic-tier test, ordered by category
and then name. The loader still reads workloads.json in a checkout from
before this change, so the gate can compare against one. The README
table follows the same order.
The zero-cost gate's I3 check (a fully typed bench workload defines no
dynamic-tier runtime symbol) runs only when someone runs the gate, and on
Darwin it never matched: Mach-O names carry a leading underscore, so no
symbol had a DYNAMIC_TIER_PREFIXES prefix.
DYNAMIC_WORKLOADS and the nm function-name reader move to
zero-cost-compare.mjs, which now drops the Mach-O underscore. A harness
test builds every bench program on Linux and fails when a workload outside
DYNAMIC_WORKLOADS links a dynamic-tier symbol, or when a listed workload
no longer links any, so the list shrinks as leaks close.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The workload's release binary links dynamic-tier symbols through its
worker messages: node:worker_threads values (Worker, parentPort,
workerData) are dyn objects, and worker.on and postMessage lower to
dynamic method calls. ThreadSlots and InternTable link none on their
own. intern-table and typed-array-scan-workers are listed for the same
reason.
The gate read an empty symbol list when nm could not start, was killed by
a signal, or exited with a non-zero status, so the dynamic-tier symbol
check and the executable comparison passed without any symbols. nmOutput
now throws with the binary, the reason and nm's stderr.
--cachegrind now also runs differing corpus executables (without
arguments, accepting intentional non-zero exits), so emitter changes that
only touch corpus programs get per-function instruction deltas. AGENTS.md
mentions the dynamic-tier symbol rule.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
scripts/zero-cost-gate.mjs compiles a fixed good-code set (the runtime
benchmark workloads, the self-hosted compiler, and the TypeScript corpus)
with a baseline and a candidate checkout. It requires byte-identical IR,
LLVM and release executables, and names the first differing IR function,
LLVM function or executable symbol when something changes. Programs that
match the change's pattern signature (--allow) may differ. It also checks
compile time (paired builds, bootstrap interval), binary size, optional
per-function cachegrind instruction counts, and the two-tier I3 symbol
rule: no executable gains dynamic-tier runtime symbols, and fully typed
benchmark workloads define none.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Chris Tate