- c12: c3's reading held on both twins — the angle as the handler's first argument + tmp reused as the later operand;
the stale 'jalr with no args' comment corrected in the 135 files whose body now passes it
- c10: jump2 cross-jump merged two walk tails (exits now fall to the single final return), the s16 SUBREG gate, and
func_80135480 called at its real arity; its answer was func_80135888 in another file
- delever_pack related.txt: lever-free bodies in the overlay sharing a func_/D_ symbol, ranked (known-true: top hit for
func_80135A4C is func_80135888); METHOD_S103 +6 emitter entries; SETUP rows
- apply-body IDENTICAL x3, propagate 131/131 x2 + 133/133; check-all 218 passed 0 failed; lever_census 19,276 marked 0 UNMARKED
Not banked, and the agent said so itself: it solved the whole tail — instructions 32 to 489 of 490 byte-identical in
plain C with the $4 pin gone — by hoisting one statement above two derived pointers, a COLOURING move rather than a
scheduling one (the scheduler's RTL order is identical in both candidates, so the tree's header note blaming it
describes the assembly, not the RTL). The head is a proven wall: find_best_addr (cse.c:2663-2665) folds the base to an
absolute address because its only set is a symbol_ref, and its known-true control keeps its base in plain C only because
both uses are at offset 0. It then labelled its two remaining improvements COMPENSATING ERRORS — a width change that
deletes the target's real andi to cancel an extra instruction — and wrote 'nothing here is bankable' instead of handing
back a 16 dressed as progress.
Two pack defects fixed from its report:
- neighbours.txt carried the @class/@stuck LINES but not the header comment they sit in, and that comment is an
eight-point English explanation of every lever in the body, including the tail crack stated outright. The pack now
ships the target's own header in full. A grep for tags is not a substitute for the paragraph it sits in.
- history.txt's line numbers are relative to the evolving text, so reconstructing a path by hand lands elsewhere (b9
reached 51 where the engine reproduces 16 in one round). The pack now ships the best candidate's text as best_body.c.
- the moves: retype four accumulators int -> short in ONE edit, delete the five hand temps that were spelling the
truncation, and type the colour temp to its destination field's own width (u8). Measured A/B/C on bytes: unsigned int
34, short 1, unsigned short 1, u8 0.
- mechanism: all four missing instructions were the same one — a move after an addiu whose result is re-read through a
16-bit shift. A narrowing assignment expands to a mode-changing copy, and combine_regs ties source into destination
only when the source DIES there (local-alloc.c:1855, return 0 at :1881); the wide temp is still live in the following
sign-extended test, so the copy survives. At int the copy is same-mode, the source dies, the tie happens, and combine
then re-selects the whole counter into the pre-shifted domain. The last instruction is cse's mode gate in insert_regs
(cse.c:1019-1021, :1029-1032).
- it confirms R20's shape and refines it: the group retype must be keyed on the residual's missing-move SET, since R12
is per-declarator and its single moves topped out at 24 here — a hill-climb cannot reach a four-way retype.
- delever_pack.py was missing an import for the neighbours block added an hour ago, so two packs shipped without
neighbours.txt and both agents said so. Fixed; all 34 packs now carry it.
- method note from the agent, now in the briefs: dump the target function WHOLE off the tree's own object rather than
reading the residual's hunks — the hunk view had scrambled two moves into branch delay slots and hid that four
differences were one repeated shape.
- the move: delete the hand-walked pointer's self-increment and recompute p = &tbl[i] from the loop counter each
iteration. The lever-free body had TWO induction variables — the loop dump says 'Cannot eliminate biv 73: biv used in
insn 50' (loop.c:5976) because the pointer is itself a call argument — and combine_givs (loop.c:5494/:5527) then
merged the three +12 field addresses into one giv whose benefit clears the not-worth-while gate at loop.c:3822-3828,
reducing it to a THIRD walking register and forcing a fourth callee-saved one: the +4 instructions and the whole
recolouring. Indexing instead leaves one biv, the +12 rides as an immediate, and the body is byte-identical.
delever --propagate: 126 of 126 sibling(s) banked, 0 refused. 26,456 -> 26,202 sites.
- THE HEADLINE IS THE METHOD, not the crack: the answer was written in English thirty lines above, in the // @class:
header of an already-matched sibling in the same file, which spells out 'recompute p = &D[i] each iteration (NOT p++)
so gcc reduces base+i*0x10 into a SINGLE pointer IV'. The pack sent agents to the cookbook and to the compiler source
and never to the target's own neighbours. This project has been leaving itself notes for months and nobody was reading
them.
- delever_pack.py now writes PACK/neighbours.txt — the comment headers of the three matched functions either side of the
target, plus every @class/@stuck/@crack note in the translation unit — and the brief makes reading it step 0.
The third agent produced no bank and a precise refutation plus a generator, which is the deliverable the brief asks for.
- it refuted the a2 hypothesis on its own body: git grep returns 1,770 declarations in two forms, both (s32 a0), no (void)
anywhere, and the pin is on a local rather than the parameter. Three lever-free spellings reach the target's complete
register assignment, so the class is reachable from plain C.
- its best is score 2, class ORDER, 89/89 instructions, every register correct, one displaced bystander store. The target's
sw sits inside the lbu->addiu window and that position is forced: anti_dependence and true_dependence (sched.c:817/845)
both hold, so the store can neither hoist nor sink. Post-sched1 stream and reg_live_length then match ours, leaving
reg_n_refs — computed by flow on the pre-combine RTL — as the only remaining input.
- R18 moves one simple statement to each other position in its own block, up to six away. R9's adjacent swap is the special
case; the distance is the point. It costs no instruction where R7's LOOP notes are a full sched1 barrier and always cost
one displaced insn, so R18 is ranked ahead of R7 in every class.
- two wrong spellings before the known-true check passed: identifier-disjointness as a requirement offered three candidates
and none of them the agent's (it is only an ordering preference now — byte-identical output is the same program, so the
oracle is the whole correctness proof, which is R9's own footing), and a blank line counted as an obstacle, so the
generator never offered the very move it was written from. It now reproduces that body exactly: bystander @21->17.
- delever_pack.py now writes each trace candidate's residual class beside its score, from the agent's method note: a bare
number hid that a move had already turned this body's residual from REG into ORDER.
- delever --selftest OK (3 new controls incl. the nested-block refusal); delever_search --selftest OK; tool_census OK.
Drew T