The two loud siblings filed in d3822d77: (a) an auto-deref *[N]T
indexed base (hs[k].result) failed cgplaceaddr's N_INDEX arm, which
knew only TY_SLICE/TY_ARRAY bases — add the one-pointer hop (the
(*hs)[k] form made implicit; load shape is the slice .ptr word's);
(b) a bare slice-element aggregate source (use(sl[k])) fell off
aggarg_srcaddr's ident-array-only N_INDEX arm into the #271 loud
stop — route the miss through the same cgplaceaddr fallback the
N_DOT arm uses. Both stages, byte-identical (probe matrix: let-copy,
field-assign, call-arg, return, indexed-store all IDENT).
After this, every ADDRESSABLE aggregate source resolves: ident
(local/module-let), deref, dot-chain, and index over array/slice/
ptr-array spines recurse through cgplaceaddr; the remaining loud
paths are rvalue sources (#40 family) and the #274 const-def arg,
both documented divergences. 8 rows added to idxdot_aggcopy_test.
The dot-chain SOURCE-address walkers (cg_dotchain_addr /
dotchainaddr) deliberately have no index hop — their AX-clean spill
contract serves the chained dotbase arm — so an aggregate copy from
elem[k].field (N_DOT over N_INDEX) fell out of the walk. Every
aggarg_srcaddr consumer loud-stopped (arg push #271, aggregate
return #272, field assign, structlit fill, ident reassign) EXCEPT
the indexed element-store arm, which left the walker's result
UNCHECKED and copied through a stale SI — a silent both-stage
miscompile (out[j] = hs[k].result read garbage). Task #6.
Both stages, two twin edits each: the aggarg_srcaddr N_DOT arm falls
back to cgplaceaddr (the C4/#40 place resolver, emission-free-on-
failure so the fallback starts clean), and the indexed store site
checks the walker before the same fallback.
Still loud (filed follow-ups): auto-deref pointer-to-array indexed
bases (hs: *[4]T; hs[k].field — cgplaceaddr's index arm takes no
deref hop; the explicit (*hs)[k].field form works), and the bare
N_INDEX slice-element aggregate source.
