simon/jolt
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
jolt/host/chez/seed
History
Yogthos f17b68ccfe backend: emit bitwise ops as native ops (test.check PRNG ~2.4x) 
Profiling the test.check distribution/large-sample slowness (jolt-i5if): the
hot path is the SplitMix PRNG, dominated by 64-bit mix arithmetic, and the
bitwise ops (bit-and/or/xor/not, shifts) were NOT in the backend native-ops
table — so (bit-xor a b) compiled to a var-deref through the variadic overlay
(__bit-xor) instead of a direct call, the way +/-/* already emit.

Map bit-and/or/xor/not to the Chez bitwise-and/ior/xor/not primitives (inlined
to native code; a non-integer operand now errors like the JVM instead of being
silently truncated) and the shifts to a direct helper call. bit-and-not stays on
its overlay — its only Scheme impl is 2-arg, so a value-position arity-3 use
would mis-emit.

mix-64 arithmetic 2.7x faster, raw split+rand-long 2.4x, gen/vector ~1.4x. The
remaining gap is the bignum-vs-native-long floor (~20x, substrate) plus the
generator machinery (deftype/fn dispatch, separate). Corpus rows added for value
position, bit-not, apply, and a full-64-bit unsigned shift.
2026-06-28 11:25:52 -04:00
..
image.ss backend: emit bitwise ops as native ops (test.check PRNG ~2.4x) 2026-06-28 11:25:52 -04:00
prelude.ss backend: emit bitwise ops as native ops (test.check PRNG ~2.4x) 2026-06-28 11:25:52 -04:00
README.md Docs: Chez-only, drop the Janet-era references and obsolete migration notes 2026-06-22 09:05:35 -04:00

README.md

Chez bootstrap seed

These two files are the bootstrap compiler for jolt — the seed that makes the build self-hosting:

  • prelude.ss — the clojure.core prelude (all tiers + clojure.string/walk/ template/edn/set/pprint) as Scheme def-var! forms.
  • image.ss — the compiler image (jolt.ir + jolt.analyzer + jolt.backend-scheme) as Scheme def-var! forms.

Both are generated, not hand-written. They are checked in because a fresh checkout must be able to build jolt-on-Chez using only Chez: host/chez/bootstrap.ss loads this seed, then rebuilds the prelude + image from the .clj/.ss sources via the on-Chez compiler (read → analyze → emit, all on Chez). The seed is a joint byte-fixpoint: rebuilding from an up-to-date seed reproduces it exactly. make selfhost (host/chez/selfcheck.sh) runs host/chez/bootstrap.ss and diffs the rebuilt artifacts against the checked-in seed.

Re-minting

When the seed sources change (the core tiers, the compiler namespaces, the host contract, the reader, emit-image.ss), the seed drifts and make selfhost fails. Re-mint it by running host/chez/bootstrap.ss and writing the freshly rebuilt prelude/image back to host/chez/seed/prelude.ss / host/chez/seed/image.ss, then commit the refreshed files.