ADR-0204 kickoff: binary-size campaign — measured baseline + levers (D-521/D-522)#144
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…D-521/D-522) Trigger: dogfooding mailbox from_cljw_05 (cljw measures zwasm at 44% of its shipped code, 4.0 MB budget line). zwasm-side symbol attribution (ReleaseSafe arm64 CLI 5,282,584 B @71cccba76) confirms and re-prioritizes: - api.jit_host_bridge = 1,311 KB / 5,453 syms (92% of api.*) — a comptime thunk cross-product (t2fp x2,880 + t1fp x960 + t0..4), NOT api surface. Lever #1 = D-522 (descriptor-driven trampolines; ABI/api unchanged). - engine.codegen.arm64.emit.compile = one 707 KB symbol (~161-arm ZirOp switch; handlers already extracted, dispatch_collector ADR-0074 substrate exists). Lever #2 = D-521 (finish registration, delete the switch; acceptance = emitted JIT bytes identical). - size_history.yaml baseline re-recorded: ReleaseFast base DOUBLED since 2026-06-12 (1,972,696 -> 3,884,856 B). Docs+ledger only; stage PRs follow separately.
jit_host_bridge instantiation axes = arg-kinds x RetKind(5) x MAX_HOST_SLOTS(64); the x64 slot axis is 94% of the product and exists only to comptime-hardcode the slot index. Stage 1 = shared FP-bridge delegation (~0.8 MB, no ABI change); stage 2 = slot-axis collapse via runtime slot conveyance (~0.4 MB, internal call-sequence change).
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enabled auto-merge (squash)
July 16, 2026 03:29
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Summary
Kickoff for the binary-size campaign (ADR-0204), triggered by dogfooding mailbox
from_cljw_05: cljw's binary-size campaign measured zwasm as its largest component (~2.99 MB of__text, 44% of all code) and sent three finished-form requests. This PR is docs + ledger only — stage PRs follow separately.Measured baseline (2026-07-16, ReleaseSafe arm64 CLI 5,282,584 B @71cccba76)
Symbol attribution (
nm -n, next-addr − addr) confirms cljw's numbers and re-prioritizes the levers:api.jit_host_bridgecomptime thunk cross-product (t2fp×2,880 + t1fp×960 + t0..4×320)engine.codegen.arm64.emit.compile(~161-arm ZirOp switch; handlers already inop_*.zig;dispatch_collectorADR-0074 substrate exists)baseseriesAlso corrected in the mailbox reply (
to_cljw_05.md, local): the x86_64 emitter already exists and is target-comptime-gated (0 B in the arm64 binary), contrary to from_cljw_05's "planned" framing.Changes
.dev/decisions/0204_binary_size_campaign.md— campaign ADR (D1 thunk collapse / D2 table-driven dispatch completion / D3 module split = only-if-free).dev/debt.yaml— new rows D-521, D-522 (front: binary-size).dev/handover.md— active-front sectionbench/results/size_history.yaml— baseline rows re-recorded (base + lean)Constraints carried from the request
No behaviour change, no JIT-output change, no API break; acceptance for D-521 = emitted JIT bytes identical (test-aot-diff + fuzz-diff); D-522 bench-gated against per-call regression.