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jolt/host/chez/seed
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Yogthos 5d0ba28128 See through or/and in truthy-elision 
A loop test like (or (>= i cap) (> ... 4.0)) desugars to
(let* [g (>= i cap)] (if (truthy? g) g (> ... 4.0))) and the whole thing was
wrapped in jolt-truthy? because returns-scheme-bool? only looked at :const and
:invoke nodes, not the let*/if an or/and expands to. The wrapper defeats Chez's
branch inlining on the hot loop edge.

Make returns-scheme-bool? recursive over :if (both branches bool), :let (body
bool, tracking which bound locals hold a Scheme boolean), and :local (in that
set). or/and over bool-returning ops then read as Scheme booleans and the outer
wrapper drops. Still sound: eliding only when the value is provably #t/#f — a
jolt-nil is a truthy record in Chez, so a false positive would be a real bug, and
the recursion only proves bool-ness through ops already known to return one.

No bench regression; the win lands on hinted float loops where the branch, not
boxed arithmetic, is the cost.
2026-06-26 02:08:00 -04:00
..
image.ss See through or/and in truthy-elision 2026-06-26 02:08:00 -04:00
prelude.ss See through or/and in truthy-elision 2026-06-26 02:08:00 -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.