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Christopher Williams bc4c046625 phase11: merge 34 + cookbook 127-129 — 556 bodies / 565 regions
Worker C's 0x8009F4B4 (248 B) and 0x80068874 (156 B), both first attempt.

127 CLOSES WORKER D'S OPEN QUESTION. D left 0x800FEE3C's magic 0x82082083 unexplained; worker C
solved it and the answer is a general rule: the divisor 63 is of the form 2^k-1, which is why
cc1 uses that magic with an ADD-BACK (mfhi; addu; sra 5) instead of a plain shift. An add-back
magic is the tell for a 2^k-1 divisor, NOT for a large one. Finding 67's decision procedure is
now complete: no mflo -> constant division D = 2^(32+s)/M; mfhi+addu+sra -> a 2^k-1 divisor;
mfhi AND mflo -> a genuine 64-bit multiply.

128: worker C classified a division-by-constant row on decode WITHOUT attempting it, because
'every division expression has several equally-plausible spellings, so it is idiom-redundant by
construction'. That characterises the ranker's false-positive class from the SOURCE side for the
first time -- exactly the class finding 110 showed cannot be separated by operand comparison.

129: adjacency is now 9-for-9 across three workers (A 3/3, C 5/5, D 1/1).
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