THE BUG (real, found by a wave agent): jtbl_range() ends a carve at the next data dlabel, assuming
every dlabel is an object boundary. spimdisasm can CUT ONE JUMP TABLE IN HALF and emit the tail
under an invented D_ label — func_8012AAAC's 50-word table is jtbl_801D7FB0 (28) + D_801D8020 (22).
The carve then reserves 112 B for an object supplying 200 B of .rodata, shifting every later symbol.
§84-class: match_one is structurally blind; it surfaces only as a whole-binary DIFF.
THE AGENT'S EVIDENCE WAS WRONG (R14): it reported D_801D8020 as having "ZERO xrefs anywhere in the
tree" and proposed deleting the label. It has TWO (.word D_801D8020 and +0x2 in tail.data.s) —
almost certainly spimdisasm mis-symbolizing packed halfword data, but "almost certainly" is not a
gate, and the proposed remedy would have deleted a symbol two emitted words reference. I built the
xref census first, watched it refuse, and only then found the references.
THE GATE USED INSTEAD — the function's own `sltiu N` range check, which gcc emits right before the
indexed load, so the PROGRAM declares its own table length (func_8012AAAC: sltiu 0x32 = 50). Absorb
only when the next label is immediately adjacent, its words are all code addresses in the overlay's
text, and absorbing lands on an EXACT sltiu bound (the SET, not max() — a multi-switch function has
several and no way to say which owns this table).
Three further corrections, each caught by testing rather than assumed:
- the absorption fired and the trailing-pad trim immediately UNDID it (re-trimming against the
first dlabel's 28 words); the trim now sees the whole absorbed table;
- a continuation ends at ITS OWN last .word, not the next dlabel (D_801D8020 ends 0x801D8078; the
next dlabel is 0x801D8158, 224 B on) — using the next dlabel is the assumption being repaired;
- the shortfall warning now fires only on an unambiguous single-bound pairing (it fired ~90 times
across 38 tables before the guard — a warning that fires on ambiguity is noise, not a signal).
VERIFIED: the split table 28 -> 50 words (112 -> 200 B), matching the agent's 3 independent
confirmations; and across 38 jtbls x 6 functions = 228 combinations, EXACTLY ONE range changes —
that table, for its owning function only.
Drew T
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