The tagged widen's source classify (`su`) single-peeled: a 2-level
chain ali->base->struct left su TY_NAMED, so an alias-NAMED struct
union member fell past the struct arm to the SCALAR arm — word0-only
payload, words 1+ zero-filled. At normal decl order this was BOTH-
WRONG-IDENTICAL with wwstage (byte-id YES, gate-blind; F0 m5b_match1
exit 2/2). Two sites, the only widen entries: cg_widen_tagged_store
(let/assign/match BP path) and cg_widen_tagged_push (the call-arg twin
— surfaced by an F1 probe: fn((void|ali)) arg ran 1/1 both-wrong-
identical). The variant TAG still keys on the un-chased st — the
member's nominal identity is the alias (cg_tag_for_variant), only the
copy-width classify chases.
CS-ONLY half: wwstage's twin (rhsstructpayload name-keyed structlookup
+ its push twin, selfhost/cmd/wcc/cgenutil.ww:3062 vs structlookupchain
:1691) lands in F2 per the serial plan — until then these shapes are
transiently cs!=ww (was identical-wrong). Bootstrap asm cmp-identical
vs a pristine 738d7f4 scratch build on all five main.combined.ww, so
the 990-997 byte-id gates are untouched.
test: 944_alias_accept_run +6 rows from the banked set
/tmp/impl62r_layer2_rows.md — L2-1/2 norm+fwd store, L2-4 3-word width
loop (last payload word checked), the push-twin arg row, L2-5 base
control (ken's gold invariant), and L2-3 (`v as ali`) pinned at task
exit 2/2/2/1 there; 64/64 green here.
Hojun-Cho
c138605563