Both stages SEGV'd identically (byte-id-blind): cgun's TK_STAR emitted
a scalar MOVQ (AX),AX for an array pointee, so the index consumed
a[0]'s VALUE as its base — a wild deref. An array value IS its address
everywhere in this cgen (#270-1a), so the ARRAY pointee now takes the
same skip as the #185 *fn deref in both stages: `*p` leaves AX = p's
value, and every consumer that materializes a complex index base via
cgexpr(base) — N_INDEX read fallback, cgassign store/compound, TK_AMP,
N_SLICE — gets the array address from the one deref choke-point.
wwstage additionally joins the N_UN-TK_STAR base to the stamped-tinfo
esz arms (cgindex / cgassign store + compound / TK_AMP &(*p)[i]) where
cstage reads base->type uniformly: without it, esz fell to the 8B
default and a narrow element would mis-stride the moment the base
started materializing (cs!=ww only reachable post-choke-point-fix,
which is why it rides this commit).
949_ptrarr_index_run grows the deref_* rows: read (8B/4B/param-base),
write (8B / 1B+neighbor-guards), compound — runtime + byte-id, the only
nets that can see a both-stages-identical miscompile.
Hojun-Cho
33ec0fb1ac