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Author SHA1 Message Date
Dmitri Sotnikov
8c9cba44b3
WP: don't let a recursive pass-through poison a param to :any (#233)
The whole-program fixpoint collects a self-recursive call's arg types into the
fn's own params. When a recursive call threads a param straight through unchanged
(same arg, same position — e.g. ray-cast passing `hittables` to itself), that arg's
type is the param's own current type: :any until external callers determine it. And
:any is absorbing, so collecting it pinned the param at :any forever — the type a
caller supplied (a vector of records) was lost, and the fn's field reads stayed
generic.

Skip a same-position pass-through arg in the self-recursion collection (contribute
the join identity). It can't add information — param i ⊇ param i is trivial — so
dropping it is sound; the param is still constrained by every external caller and
by any non-pass-through recursive arg. Applies to both self-recursion paths: a
`defn` recursing through its var, and a named fn literal recursing via its
self-local.

This is why ray-cast's `ray` typed (its recursion passes a fresh ray) but
`hittables` didn't (passed through). With the fix, hittables keeps its
vec<Sphere> element type, so hit-all's reduce element — and hit-sphere's reads —
type without any hint: ray tracer 38.4s -> 31.3s (~1.23x) with no annotations.

run-wp.ss: a recursive fn threading a vec param through keeps its element type.
make test / shakesmoke green, selfhost holds, 0 new divergences.

Co-authored-by: Yogthos <yogthos@gmail.com>
2026-06-26 16:29:46 +00:00
Dmitri Sotnikov
09712ec575
Whole-program param-type inference (closed world) (#226)
Re-derive each app fn's param types from its call sites under --opt, so a
record type flows across fn boundaries: a ctor's return reaches a callee
param, and a typed vector's element reaches a HOF closure's param. The back
end can then bare-index field reads and devirtualize protocol calls at those
sites (it reads the resulting :hint/:devirt annotations; consuming them is
separate work).

This rebuilds the inter-procedural driver the Janet host had — the API
(infer-body/reinfer-def) survived the rehost but nothing drove it, and the
record-shapes/protocol-methods registries were empty stubs.

- records.ss: populate record-shapes (ctor key -> fields/tags/type, resolving
  nested record field tags) and protocol-methods (method var -> [proto method])
  registries at deftype/defprotocol load time; jolt.host accessors materialize
  them.
- passes/types.clj: wp-infer! runs a closed-world fixpoint joining call-site
  arg types into callee params; reinfer-def re-seeds each def at emit. Self-
  recursive calls and fn-level recur are collected so a recursive fn's params
  are constrained by its recursion, not just external callers — else a param
  the recursion widens (e.g. binary-trees check-tree, whose untagged child can
  be nil) would be unsoundly typed non-nil. A fn used in value position keeps
  :any params (callers unknown). Megamorphic sites join to :any.
- build.ss: analyze all app forms and run the fixpoint before per-form emit.
- run-wp.ss: gate (cross-fn propagation, escape soundness, self-recursion).

make test / shakesmoke green, 0 new divergences, selfhost holds.

Co-authored-by: Yogthos <yogthos@gmail.com>
2026-06-26 10:57:45 +00:00