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Drew T
b6bb04ecff
Drew: "if it fails, see why and try again with new knowledge." It failed twice, then banked.
ROOT CAUSE, byte-proven: a family_remap member reached match_one MATCH (240 ins) and failed the
whole-binary gate by ONE BYTE. The exemplar carries a deliberate matching idiom — reach a symbol via
a DIFFERENT symbol plus a literal offset, so gcc cannot CSE the two %hi/%lo pairs:
(*(S9*)&D_801DAA78) = *(S9*)(&D_801DA998 + 0x20); /* same addr as &D_801DA9B8 */
family_remap substitutes the symbol NAMES correctly and leaves the literal 0x20 — but 0x20 is not a
constant of the algorithm, it is the DISTANCE BETWEEN TWO PER-OVERLAY SYMBOLS:
exemplar 0x801DA998 + 0x20 = 0x801DA9B8 OK
member 0x801A5778 + 0x20 = 0x801A5798 WRONG (real symbol 0x801A5790)
member 0x801A5778 + 0x18 = 0x801A5790 correct
match_one MASKS HI16/LO16 so it is STRUCTURALLY BLIND to this — the §81 blindness in its DATA form.
TWO FIXES WERE EACH INDIVIDUALLY INSUFFICIENT: the byte fix alone re-failed as PLUMBING; the ladder
alone re-failed as DIFF. Together -> BANKED, R22 clean-fleet 140/140.
TWO LADDER CORRECTIONS (my own T0.2 error): bare harvest_verify is the LAST RUNG, not the ladder —
gate_stage runs canon_resident_calls -> cast_call_sites -> reconcile_tu -> ARITY -> sig_unify ->
harvest_verify, so T0.2's "8/8 PLUMBING" measured the UN-RECOVERED rate. And reconcile_decls.py is
RETIRED (R33, superseded by reconcile_tu): asking "what does the FLEET call this symbol?" is wrong by
construction in a loosely-typed engine (548 of its answers conflicted, rewriting 60 of 196 drafts) —
so Drew's suggested tool would have made it worse.
SCOPE, MEASURED (not over-generalised, §80): the idiom appears at only 5 sites corpus-wide — BUT one
gates a 123-member family (133 staged drafts all carry the un-recomputed +0x20 with different
per-overlay bases), so the mechanical fix is worth ~240 ins x 123 ~= 29,520 ins. It does NOT explain
the pool generally: func_80144090 / func_8012CC88 / func_8014D12C have ZERO derived-offset sites and
fail for a different, still-undiagnosed cause.
THE FIX IS MECHANICAL: correct_literal = mapped(aliased_sym) - mapped(base_sym). The remap already
holds both mappings, and the exemplar's own comment names the aliased symbol.
Also observed: the ARITY pre-pass left 40 TUs of caller-decl edits after a 0-bank run (same hygiene
bug as --normalize-self-decls, twice in one session) — reverted, both binaries byte-identical.