Files
ww/selfhost/cmd
Hojun-Cho a78b26c2d3 selfhost/cmd/wcc: extend tinfo coverage + graduate slotsize fast-path (Phase A.2)
tinfofornode (check.ww) covers six more kinds:
- N_TARRAY: typearray on recursed element, size = esz * elen.
- N_TFN: 8B/8B; recurse on ret.
- N_TENUM: storage size/align (default i32 → 4B). Mirrors cstage
  check.c:531-542.
- N_TTUPLE: raw element sum + max-align. Mirrors check.c:329-345.
- N_TSTRUCT: per-field align, round total to maxalign. Mirrors
  check.c:280-340 / :468-527.
- N_TTAGGED: 8B tag + (max(variant)+7)&~7, al ≥ 8. Mirrors
  check.c:347-435.

Cycle-prone arms (TFN/TTUPLE/TSTRUCT/TTAGGED) pre-bind the in-progress
tinfo into the cache BEFORE recursing on subfields so self-referential
shapes (`type node = struct { next: *node, … }`) terminate. Pre-fix
wwdump_ww segfaulted on its own combined source.

More population sites in exprtype: every primitive literal arm
(N_FLOATLIT/N_STRLIT/N_RUNELIT/N_TRUE/N_FALSE/N_VOIDLIT/N_NIL —
A.1 only had N_INTLIT), N_IDENT (propagate from sym.decl.lhs.type_,
eagerly tinfofornode + cache if not yet visited), resolvewalk type-expr
stamping, and resolvefnbody now recurses into N_PARAM.lhs (pre-#61 the
param type-exprs were never walked — every param had nil type_).

slotsize (cgenutil.ww) gains a fast-path: when n.type_ is set AND the
kind is PTR / SLICE / CHAN / FN / STR, return ti.size: i32 directly.
The fallback walker stays alive for primitive scalars, enums, named
structs, inline composites, TARRAY — those need cstage's let_emit_size
slot-pad-to-8 contract (cmd/w6c/cgen.c:691-720) which tinfo doesn't
carry. A.3+ moves padding into the fast-path.

TY_TAGGED *not* in the fast-path (reviewer-61a2 caught this) —
tinfofornode's TTAGGED arm doesn't implement cstage's nullable-pointer
fold (check.c:412-426: `(*T | void) → 8B`). Self-host code happens not
to use that shape today, but the divergence would land latent. Pull
TAGGED until A.3 folds nullable into tinfofornode.

A.2 fallback-hit count under wwdump build: 1554 fast vs 2187 fallback —
partial graduation; expected. 131/131 + 994 + 995 + bootstrap
byte-identical (ww2==ww3==ww4).
2026-05-20 12:17:16 +09:00
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