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Hint-directed fast arithmetic: fl*/fx* from ^double/^long (round 1)

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A ^double/^long param hint (or a float literal) now drives Chez flonum/fixnum
ops instead of generic arithmetic — JVM-style primitive hints, available in every
build and at -e (not gated on direct-linking or whole-program inference).

New pass jolt.passes.numeric: a local forward type-flow seeded from ^double/^long
fn-param hints (analyzer attaches :nhints per arity) and float literals,
propagated through let inits / arithmetic / if / do. It tags an arithmetic invoke
:num-kind :double|:long when every operand is that kind (an integer literal is a
wildcard, coerced to a flonum in a double op). The back end lowers a tagged node
to fl+/fl-/fl*/fl//fl<?/... or fx+/fx*/fx1+/fxquotient/... (unchecked-add etc.
join the fixnum path; == too). Runs last in run-passes, both branches.

Soundness: :long is seeded ONLY from an explicit ^long hint, never a bare integer
literal, so un-hinted integer code keeps jolt's arbitrary-precision numbers — no
fixnum-overflow surprise, no corpus divergence. :double comes from ^double hints
and float literals (flonum arithmetic is always flonum, matching the generic
result). A ^long hint is a promise the value is a fixnum: fx+ raises on overflow,
like a JVM fixed-width long.

Numeric-hinted params coerce at fn entry (exact->inexact / jolt->fx), the way the
JVM coerces a primitive parameter — so the body's fl*/fx* ops can rely on the
type even when a caller passes an exact int (e.g. Chez's (* 0 1.0) => exact 0).

Round 1 specializes hinted straight-line / fn-body arithmetic. fl-ops are ~4x
generic in a tight Chez loop, but realizing that on loop-carried accumulators
needs loop-var typing — round 2. Sound foundation, gated by test/chez/numeric-test.ss.
This commit is contained in:
Yogthos 2026-06-23 16:43:55 -04:00
parent 2c18fcdc61
commit 59905a71fd
9 changed files with 567 additions and 236 deletions
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9
Makefile
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@ -4,7 +4,7 @@
# build step. `make test` is the full gate. `make remint` rebuilds the seed after a
# source change.
.PHONY: test ci values corpus unit smoke buildsmoke selfhost sci certify ffi transient infer directlink remint
.PHONY: test ci values corpus unit smoke buildsmoke selfhost sci certify ffi transient infer directlink numeric remint
# Full gate (dev machine). Includes the self-host byte-fixpoint, which only holds
# on the same Chez that minted the seed.
@ -15,7 +15,7 @@ test: selfhost ci
# lockfile) — it RUNS correctly on any Chez, but `selfhost` rebuilds it and a
# different Chez version may emit byte-different (gensym/order) output, so the
# byte-fixpoint is a dev-machine check, not a CI one (jolt-8479).
ci: values corpus unit smoke buildsmoke sci ffi transient infer directlink certify
ci: values corpus unit smoke buildsmoke sci ffi transient infer directlink numeric certify
@echo "OK: CI gates passed"
# Self-host fixpoint: bootstrap.ss rebuild == checked-in seed.
@ -67,6 +67,11 @@ infer:
directlink:
@chez --script test/chez/directlink-test.ss
# Hint-directed fast arithmetic: ^double/^long param hints (and float literals)
# lower arithmetic to Chez fl*/fx* ops; un-hinted integer code stays generic.
numeric:
@chez --script test/chez/numeric-test.ss
# JVM oracle: certify the corpus against reference Clojure. Skips if clojure absent.
certify:
@if command -v clojure >/dev/null 2>&1; then \