Finding 84 named the transform; it is now implemented and 0x800FFBEC matches (80 B, 0 differing)
where it was 6 differing bytes without it.
IT IS A SWAP, NOT A MOVE, and getting that wrong cost one implementation: the candidate is
lw $31,16(sp) / addiu sp,sp,24 / jr $31 / nop and the original is lw $31 / nop / jr $31 /
addiu sp,sp,24 -- SAME instruction count, two words swapped. My first version moved the release
after the jump and dropped the nop, producing 3 instructions instead of 4 and turning an 80-byte
row into a 76-byte LENGTH-MISMATCH. A 'small mechanical transform' still has to be checked
against the bytes.
SCALE: 120 unclaimed rows have the filled epilogue in the ORIGINAL (scanned every worklist row's
tail for jr $31 followed by a positive addiu sp,sp,N). They are mostly SMALL -- 76, 76, 80, 92,
92, 96, 104 B -- so this is a large class of cheap rows that were blocked on a HARNESS GAP rather
than on source shape. 770 other rows have the unfilled shape and need nothing.
The tracked patch is regenerated and verified to reproduce both modified maspsx files from the
pristine checkout.
Christopher Williams
05be974ce2