Levers — the register pins and compiler hints, what they cost, and what to do about them

What this is. The living record of every compiler-forcing construct in this decompilation: how many there are, how they got in, how they come out, and — the part that outlives the project — whether a decomp should refuse them from its first bank or clean them up at the end. The numbers below are generated (R75); the argument is written from them.

Maintained: updated at the close of every Phase-36 task (tools/lever_progress.py --snapshot "<task>", which also re-renders the tables here). Sources: tools/lever_census.py for the counts, .run/P36/delever/ledger.jsonl for the campaign, docs/lever-progress.tsv for the series a chart is drawn from.

Audiences: the post-100% chart and the project story · the wiki (a "Levers" page) · decomp-architect/ (the day-one kit: the rule a new project should adopt at its first bank, §"What we would do from day one").

1. What a lever is

A lever is a construct that exists only to force the compiler's output — it says nothing about what the program does. This project's C is full of them because bytes were the only thing being optimised:

class	what it looks like	why a drafter reached for it
A register pin	`register s32 x __asm__("$16");`	name the register the allocator must use
B1 barrier	`__asm__ __volatile__("" ::: "memory");`	stop the scheduler moving code across a point
B2 launder	`__asm__("" : "=r"(x) : "0"(x));`	break a value's history so cse/combine cannot see through it
B3 keep-alive	`__asm__("" : : "r"(x));`	keep a dead value live
B4 hand-placed instruction	`__asm__("addu %0,%1,$zero" …)`	emit exactly this instruction
B5 GTE op	`__asm__("lwc2 …")` behind a per-TU macro	not a lever — Sony's coprocessor idiom; consolidated, not removed
C volatile	`(volatile s32 )(p + 4)`	force a reload
D bare `register`	`register int i;`	a hint gcc 2.7.2 at `-O2` ignores
E asm-label alias	`extern u16 aD800B9A02 __asm__("D_800B9A02");`	a second typed view of one symbol
F builtin	`__builtin_memcpy(&a, &b, N)`	a struct assignment in disguise
G attribute	`__attribute__((packed))`	a layout the type layer should carry

Classes A and B are the ones this phase drives to zero. C and D stay if the bytes need them (ordinary C, ledgered and counted, not marked). E, F and G belong to the canonical type layer and are the types phase's work (R95).

2. The numbers

Milestones — the count, at each moment a census ran

date	milestone	pins	asm	class A+B sites	bodies	distinct	GTE levers	per-TU asm macros	C	D	E	F	G	HEAD
2026-09-09	T6 r1 (rung R's first class)	20512	13445	33957	12578	1758	462	314	1722	50	7428	445	76	`1761a3125`
2026-09-09	T6 d1 (rung D's four exemplars)	20508	13445	33953	12574	1758	462	314	1722	50	7428	445	76	`8fac96651`
2026-09-09	T6 p1 (four classes propagated)	19982	13445	33427	12048	1755	462	314	1722	50	7428	445	76	`a2da99b13`
2026-09-09	S101 rung G g1 (the guided search's first run: 1 of 16 exemplars, 132 bodies)	19982	13313	33295	11916	1754	462	314	1590	50	7428	445	76	`623e55340`
2026-09-09	S101 rung G g2 (wider beam + R10/R12/R13/R8-cse: 1 of 16, 132 bodies)	19718	13313	33031	11784	1753	462	314	1590	50	7428	445	76	`584031c71`
2026-09-09	S101 rung G g3 (the next 64 classes: 13 of 64, 1,516 bodies)	18442	12583	31025	10268	1740	462	314	1590	50	7428	445	76	`5ae0b5ceb`
2026-09-09	S101 rung G g4s (the 13 explained names, 38 classes: 3 of 38, 133 bodies)	18309	12583	30892	10135	1737	462	314	1590	50	7428	445	76	`068781ae0`
2026-09-09	S101 rung G g5 (the head re-drawn wide: 5 of 70, 62 bodies)	18261	12545	30806	10073	1732	462	314	1590	50	7428	445	76	`1ec67f667`
2026-09-09	S101 rung G g6 + g6b (the tail: 47 + 63 of 400 small classes, 93 + 186 + 47 bodies)	17954	12404	30358	9747	1624	462	314	1590	50	7428	445	76	`2f3ce92a1`
2026-09-10	S102 T7 a1 — func_80156044 closed by an agent (merge-point expression sunk into the if/else arms, both $2/$3 pins gone); 130 bodies banked (1 + 129 propagated)	17694	12404	30098	9617	1623	462	314	1590	50	7428	445	76	`5a8bd1021`
2026-09-10	S102 T7 s1 — the R15 sweep of the head: 6 exemplars closed by the sink alone (267 bodies), no drafting tokens	17427	12270	29697	9350	1617	462	314	1590	50	7428	445	76	`861dd0651`
2026-09-10	S102 T7 a2 — func_80168828: the constant-holder pin deleted and one adjacent swap closes it (125 bodies, 1 of 2 pins off; the $4 pin is forced by the header's (void) declaration)	17302	12270	29572	9350	1617	462	314	1590	50	7428	445	76	`c00ffe5d4`
2026-09-10	S102 T7 s3 (partial, the run crashed in propagate) — the constant-holder draw: 10 bodies closed	17266	12267	29533	9326	1594	462	314	1590	50	7428	445	76	`975850ff8`
2026-09-10	S102 T7 s3b — the constant-holder draw re-run after the propagate fix: 1 of 80, 6 bodies; 59 of 80 hit the compile budget	17260	12267	29527	9320	1593	462	314	1590	50	7428	445	76	`5603a114c`
2026-09-10	S102 T7 s5 — the first broad TAIL sweep with R15/R16/R17/R18: 285 of 800 bodies closed lever-free, no drafting tokens	17029	12175	29204	9035	1308	462	314	1590	50	7428	445	76	`449acd8cb`
2026-09-10	S102 T7 s6 — the last never-attempted exemplars: 25 of 337; the fresh pool is now empty	16996	12152	29148	9010	1283	462	314	1590	50	7428	445	76	`67e91ad4d`
2026-09-10	S102 T7 s7 (stopped early to restore agent cadence) — 5 of 207 judged at the wider width	16989	12151	29140	9005	1280	462	314	1590	50	7428	445	76	`724c68859`
2026-09-10	S102 T7 a7 — func_801287B8: a truncated local extern was faking a pin; the missing call argument restored through a function-pointer cast (127 bodies)	16862	12151	29013	8878	1279	462	314	1590	50	7428	445	76	`bb0e95c7c`
2026-09-10	S102 T7 a4 — func_8016C49C: one do-while on the function's LAST statement doubles a loop-note reference weight and flips allocno_compare (126 bodies)	16736	12151	28887	8752	1278	462	314	1590	50	7428	445	76	`9f5b22176`
2026-09-10	S102 T7 burst — a8/a12/a18/a19 banked (132+118+119+134 bodies): the call-arity class twice, a MEM_IN_STRUCT_P alias flip, and a sequence-point split	15965	12019	27984	8249	1275	462	314	1590	50	7428	445	76	`fb6c857f7`
2026-09-10	S102 T7 burst — a5/a9/a11/a16/a25 banked; the MISSING CALL ARGUMENT class confirmed six times independently (m2c dropped arguments at unprototyped and indirect call sites)	15324	11390	26714	7612	1271	462	314	1590	50	7428	445	76	`c6b380fcd`
2026-09-10	S102 T7 burst — a22 banked (126); a14 REFUSED as an invented zero term; a6/a10/a15 read without closing	15198	11264	26462	7486	1270	462	314	1590	50	7428	445	76	`374c8a0e9`
2026-09-10	S102 T7 s8 — the first R19 sweep: 3 of 55 classes closed by restoring a dropped call argument, 2 compiles each	15193	11263	26456	7483	1267	462	314	1590	50	7428	445	76	`f3de70fce`
2026-09-10	S102 — 16,759 lying call declarations repaired free (3,439 units, R22 218/218); levers unchanged, truth improved	15193	11263	26456	7483	1267	462	314	1590	50	7428	445	76	`51028a78d`
2026-09-10	S102 T7 b1 — func_801651B8: the hand-walked pointer folded back into the index, one induction variable instead of two (127 bodies)	15066	11136	26202	7356	1266	462	314	1590	50	7428	445	76	`8c0e7c549`
2026-09-10	S102 T7 b3 — func_8016CBC0: two counter chains narrowed TOGETHER (128 bodies); single declarations could never reach it	14938	11136	26074	7228	1265	462	314	1590	50	7428	445	76	`acba5c59d`
2026-09-10	S102 T7 wave b — b2/b5/b5s/b6 banked plus R19 and R20's own closes (766 bodies): a chained assignment, a symbol alias defeating cross-jump, and the store hoisted above its copy	14541	10374	24915	6577	1259	462	314	1590	50	7680	445	76	`9d78fc408`
2026-09-10	S102 T7 b7 — func_80166690: four accumulators retyped short in ONE edit, the truncation temps deleted, the colour temp typed to its destination field (126 bodies)	14415	10374	24789	6451	1258	462	314	1590	50	7680	445	76	`17d192d24`
2026-09-10	S102 T7 b8 — func_80135888: a guarded do-while defeating cross-jump, a duplicated block replaced by goto to shed one loop-weighted reference, and a two-arm temp inlined (134 bodies, the largest class)	13879	10240	24119	6317	1257	462	314	1590	50	7680	445	76	`0d92d1029`
2026-09-10	S102 wave b close — 8 agent closes banked (b1/b2/b3/b5/b5s/b6/b7/b8), b4/b9 read without closing; R19/R20/R21 added; fleet 218/218	13879	10240	24119	6317	1257	462	314	1590	50	7680	445	76	`f96af3e48`
2026-09-10	S103 c2: func_8013D8FC closed by agent c2 (the walked-pointer merge, now generator R22), 131 bodies	13748	10240	23988	6186	1256	462	314	1590	50	7680	445	76	`82da34b39`
2026-09-10	S103 wave c: c4/c6/c1/c7/c3/c5/c8 closed (two new generators R22/R23) + func_8017EEC0's parameter; 8 classes, ~1,000 bodies	11271	8935	20206	5277	1249	462	314	1590	50	7680	445	76	`205331765`
2026-09-10	S103: c12 twins func_80148E54/D44 + c10 func_80135A4C (395 bodies)	10873	8403	19276	4879	1246	462	314	1590	50	7680	445	76	`2e61220bd`
2026-09-10	S103: c11 func_80175AB8 (124 bodies)	10623	8153	18776	4754	1245	462	314	1590	50	7680	445	76	`e6a8f3505`
2026-09-10	S103: c14 func_801670E4 + c16 func_8013D178 (261 bodies); R23 widened	10227	7488	17715	4491	1243	462	314	1590	50	7680	445	76	`625251626`
2026-09-10	S103: delever_regen R22+R23 over the whole residue — 17 classes / 22 bodies with no agent (header-TU scoring fixed)	10204	7488	17692	4469	1226	462	314	1590	50	7680	445	76	`a06070572`
2026-09-10	S103: c18 func_80176734 (128 bodies)	9172	7101	16273	4340	1225	462	314	1590	50	7680	445	76	`164825b5d`
2026-09-10	S103: c20 re-draw func_8013DD68 (128 bodies)	8914	7101	16015	4211	1224	462	314	1590	50	7680	445	76	`9f2b6b24a`
2026-09-10	S103: generator R24 (word-read addPrim) + its regen pass (2 classes, one a 140-object header)	8912	7101	16013	4209	1222	462	314	1590	50	7680	445	76	`5eb46b267`
2026-09-10	S103: c15 func_80135EB0 (128 bodies; a do-while on the a4 precedent)	8654	6585	15239	4080	1221	462	314	1590	50	7680	445	76	`a620e1880`
2026-09-10	S103: re-draws c24 func_8012956C + c23 func_80133784 (252 bodies)	7765	6077	13842	3826	1219	462	314	1590	50	7680	445	76	`ae87bf75a`
2026-09-10	S103: re-draws c25 func_80166F58 + c26 func_80133CD4 (254 bodies); R25 regen 3; propagate's stale-hash fix	7512	5571	13083	3567	1215	462	314	1590	50	7680	445	76	`96820256c`
2026-09-10	S103: re-draw c21 func_801397B0 (125 bodies; do-while ref-weight)	7386	5571	12957	3441	1214	462	314	1590	50	7680	445	76	`44f7f8ddb`
2026-09-10	S103: re-draw c30 func_8017B614 (125 bodies)	7260	5319	12579	3315	1213	462	314	1590	50	7680	445	76	`5ddbc3a7f`
2026-09-10	S103: c33 func_80169058 + func_80168D94 (12 bodies)	7236	5295	12531	3303	1211	462	314	1590	50	7680	445	76	`a2a1fc186`
2026-09-10	S103: c36 + c35 (four ov_SC07_006/ov_SC06_010 classes, 39 bodies); R19 reads cast arity	7186	5295	12481	3260	1207	462	314	1590	50	7680	445	76	`dd5e44c24`
2026-09-10	S103: extern-variant re-propagation (97), R19 cast regen (8 classes), c39 + c41 + c34 + c32 closes	6926	5107	12033	3090	1164	462	314	1590	50	7688	445	76	`7d5964b27`
2026-09-10	S103: c38 + c40 (four tier classes, 30 bodies)	6910	5093	12003	3060	1160	462	314	1590	50	7688	445	76	`321b540e7`
2026-09-10	S103: c42 func_80186A8C + func_80182058 (10 bodies)	6900	5088	11988	3050	1158	462	314	1590	50	7688	445	76	`2a4f28f83`
2026-09-10	S103: c46 minimum-lever (133 bodies, 23 -> 1), c43 + cross-address port (14+12), c44, c45 (+R26), c37 + 43 cross-address copies, port-scan	5893	4048	9941	2946	1144	456	314	1590	50	7713	445	76	`8bc06a2cb`
2026-09-10	S103: c50 func_80136824 zero levers (130); c49 func_8013F350 2 levers (133)	5500	3528	9028	2816	1144	456	314	1590	50	7713	445	76	`aada3bdc2`
2026-09-10	S103: c47 func_8013D9B0 2 GTE asm (133), c48 func_80140958 2 levers (133), c52 four R26 closes	3069	2323	5392	2662	1134	456	314	1590	50	7733	445	76	`433aa0701`
2026-09-10	S103: c56 ports func_8013D9B0 to ov_MAIN_012's class (7); c54 func_8017B238 (8)	3061	2315	5376	2654	1131	456	314	1590	50	7733	445	76	`c02fc7cd5`
2026-09-10	S103 end: R26 regen 28 classes (71 bodies) + c55/c53 five classes	2932	2299	5231	2569	1098	456	314	1590	50	7782	445	76	`0ef49b515`
2026-09-10	S103 end: c51 func_8012E364 2 levers (134); scrub of 46 orphan markers	2798	2299	5097	2569	1097	456	314	1590	50	7782	445	76	`94520756e`
2026-09-10	S104 T7: free sweep (5 classes) + agents d1–d9 (all 0; 8 with zero levers, d4 one marked do-while)	2730	2233	4963	2498	1077	456	314	1590	50	7782	445	76	`910875139`
2026-09-10	S104 T7: sweeps (all-families, R27) + agents d11–d19 all at 0 with zero levers	2578	2175	4753	2383	1019	456	314	1590	50	7780	445	76	`91ae94a64`
2026-09-10	S104 T7: d17 + R28–R33 pass (4) + R27 remainder	2565	2167	4732	2373	1011	456	314	1590	50	7780	445	76	`13069c142`

The campaign — every batch, from the ledger (derived on every render)

batch	date	rungs	bodies first judged	sites removed	rewritten	sites closed later	bodies made lever-free
`t3_tus1`	2026-09-09	A,B	176	211	4	0	0
`t3_scrub`	2026-09-09	scrub	1	0	0	0	0
`tus1`	2026-09-09	A,B,replay	1,392	3,241	101	0	0
`tus2`	2026-09-09	A,B,replay	2,752	3,501	4	0	0
`tus3`	2026-09-09	A,B,replay	2,513	2,910	15	0	0
`tus4`	2026-09-09	A,B,replay	2,224	2,012	131	0	0
`tus5`	2026-09-09	A,B,replay	1,225	1,811	10	0	0
`tus6`	2026-09-09	A,B,replay	1,409	1,667	0	0	0
`tus7`	2026-09-09	A,B,replay	1,407	1,853	2	0	0
`tus8`	2026-09-09	A,B,replay	602	432	0	0	0
`tus9`	2026-09-09	A,B,replay	1,901	2,234	10	0	0
`tus10`	2026-09-09	A,B,replay	362	408	3	0	0
`headers1`	2026-09-09	A,B,replay	200	301	1	0	0
`headers2`	2026-09-09	A,B,replay	171	197	2	0	0
`gte1`	2026-09-09	gte	399	0	0	0	0
`gte2`	2026-09-09	gte	244	0	0	0	0
`sweep1`	2026-09-09	sweep	4	0	0	0	0
`sweep2`	2026-09-09	sweep	3	0	0	0	0
`sweep3`	2026-09-09	sweep	134	0	0	0	0
`r1`	2026-09-09	R	0	0	0	134	134
`d1`	2026-09-09	D	0	0	0	4	4
`p1`	2026-09-09	D	0	0	0	394	394
`p1b`	2026-09-09	D	0	0	0	132	132
`g1`	2026-09-09	G	0	0	0	2	1
`g1p`	2026-09-09	G	0	0	0	262	131
`g2`	2026-09-09	G	0	0	0	2	1
`g2p`	2026-09-09	G	0	0	0	262	131
`g3`	2026-09-09	G	0	0	0	17	13
`g3p`	2026-09-09	G	0	0	0	1,989	1,503
`g4s`	2026-09-09	G	0	0	0	3	3
`g4sp`	2026-09-09	G	0	0	0	130	130
`g5`	2026-09-09	G	0	0	0	7	5
`g5p`	2026-09-09	G	0	0	0	79	57
`g6`	2026-09-09	G	0	0	0	66	47
`g6b`	2026-09-09	G	0	0	0	72	63
`g6bp`	2026-09-09	G	0	0	0	39	30
`g6p`	2026-09-09	G	0	0	0	275	186
`a1`	2026-09-10	E	0	0	0	2	1
`a1p`	2026-09-10	E	0	0	0	258	129
`s1`	2026-09-10	G	0	0	0	10	6
`s1p`	2026-09-10	G	0	0	0	391	261
`a2`	2026-09-10	E	0	0	0	1	0
`a2p`	2026-09-10	E	0	0	0	124	0
`s3`	2026-09-10	G	0	0	0	39	24
`s3b`	2026-09-10	G	0	0	0	1	1
`s3bp`	2026-09-10	G	0	0	0	5	5
`s4`	2026-09-10	G	0	0	0	18	3
`s5`	2026-09-10	G	0	0	0	325	285
`s6`	2026-09-10	G	0	0	0	56	25
`s7`	2026-09-10	G	0	0	0	8	5
`a7`	2026-09-10	E	0	0	0	1	1
`a7p`	2026-09-10	E	0	0	0	126	126
`a4`	2026-09-10	E	0	0	0	1	1
`a4p`	2026-09-10	E	0	0	0	125	125
`a8`	2026-09-10	E	0	0	0	2	1
`a8p`	2026-09-10	E	0	0	0	262	131
`a12`	2026-09-10	E	0	0	0	1	1
`a19`	2026-09-10	E	0	0	0	3	1
`a18`	2026-09-10	E	0	0	0	1	1
`a12p`	2026-09-10	E	0	0	0	117	117
`a19p`	2026-09-10	E	0	0	0	399	133
`a18p`	2026-09-10	E	0	0	0	124	124
`a5`	2026-09-10	E	0	0	0	4	1
`a5p`	2026-09-10	E	0	0	0	500	125
`a9`	2026-09-10	E	0	0	0	2	1
`a9p`	2026-09-10	E	0	0	0	256	128
`a25`	2026-09-10	E	0	0	0	2	1
`a16`	2026-09-10	E	0	0	0	1	1
`a25p`	2026-09-10	E	0	0	0	250	125
`a16p`	2026-09-10	E	0	0	0	130	130
`a11`	2026-09-10	E	0	0	0	1	1
`a11p`	2026-09-10	E	0	0	0	124	124
`a22`	2026-09-10	E	0	0	0	2	1
`a22p`	2026-09-10	E	0	0	0	250	125
`s8`	2026-09-10	G	0	0	0	6	3
`b1`	2026-09-10	E	0	0	0	2	1
`b1p`	2026-09-10	E	0	0	0	252	126
`b3`	2026-09-10	E	0	0	0	1	1
`b3p`	2026-09-10	E	0	0	0	127	127
`s10`	2026-09-10	G	0	0	0	2	2
`b2`	2026-09-10	E	0	0	0	3	1
`b5`	2026-09-10	E	0	0	0	1	1
`b6`	2026-09-10	E	0	0	0	3	1
`b5s`	2026-09-10	E	0	0	0	1	1
`b2p`	2026-09-10	E	0	0	0	378	126
`b5p`	2026-09-10	E	0	0	0	125	125
`b6p`	2026-09-10	E	0	0	0	378	126
`s10p`	2026-09-10	G	0	0	0	128	128
`s10q`	2026-09-10	G	0	0	0	15	15
`b5sp`	2026-09-10	E	0	0	0	125	125
`b7`	2026-09-10	E	0	0	0	1	1
`b7p`	2026-09-10	E	0	0	0	125	125
`b8`	2026-09-10	E	0	0	0	5	1
`b8p`	2026-09-10	E	0	0	0	665	133
`c2`	2026-09-10	E	0	0	0	1	1
`c2p`	2026-09-10	E	0	0	0	130	130
`c4`	2026-09-10	E	0	0	0	4	1
`c4p`	2026-09-10	E	0	0	0	532	133
`c6`	2026-09-10	E	0	0	0	4	1
`c6p`	2026-09-10	E	0	0	0	516	129
`c1`	2026-09-10	E	0	0	0	5	1
`c1p`	2026-09-10	E	0	0	0	625	125
`c7`	2026-09-10	E	0	0	0	5	1
`c7p`	2026-09-10	E	0	0	0	665	133
`c3`	2026-09-10	E	0	0	0	6	1
`c3p`	2026-09-10	E	0	0	0	786	131
`c5`	2026-09-10	E	0	0	0	1	1
`c5p`	2026-09-10	E	0	0	0	125	125
`c8`	2026-09-10	E	0	0	0	4	1
`c8p`	2026-09-10	E	0	0	0	504	126
`c12`	2026-09-10	E	0	0	0	4	2
`c12p`	2026-09-10	E	0	0	0	524	262
`c10`	2026-09-10	E	0	0	0	3	1
`c10p`	2026-09-10	E	0	0	0	399	133
`c11`	2026-09-10	E	0	0	0	5	1
`c11p`	2026-09-10	E	0	0	0	620	124
`c14`	2026-09-10	E	0	0	0	7	1
`c14p`	2026-09-10	E	0	0	0	924	132
`c16`	2026-09-10	E	0	0	0	1	1
`c16p`	2026-09-10	E	0	0	0	129	129
`s103_r22r23`	2026-09-10	E	0	0	0	15	14
`s103_r22r23p`	2026-09-10	E	0	0	0	4	4
`s103_r22r23_hdr`	2026-09-10	E	0	0	0	3	3
`s103_r22r23_hdrp`	2026-09-10	E	0	0	0	1	1
`c18`	2026-09-10	E	0	0	0	11	1
`c18p`	2026-09-10	E	0	0	0	1,408	128
`c20`	2026-09-10	E	0	0	0	2	1
`c20p`	2026-09-10	E	0	0	0	256	128
`s103_r24`	2026-09-10	E	0	0	0	4	2
`c15`	2026-09-10	E	0	0	0	6	1
`c15p`	2026-09-10	E	0	0	0	768	128
`c24`	2026-09-10	E	0	0	0	4	1
`c24p`	2026-09-10	E	0	0	0	504	126
`c23`	2026-09-10	E	0	0	0	7	1
`c23p`	2026-09-10	E	0	0	0	882	126
`c25`	2026-09-10	E	0	0	0	5	1
`c25p`	2026-09-10	E	0	0	0	617	124
`c26`	2026-09-10	E	0	0	0	1	1
`c26p`	2026-09-10	E	0	0	0	130	130
`s103_r19r25`	2026-09-10	E	0	0	0	4	3
`s103_r19r25p`	2026-09-10	E	0	0	0	1	1
`c21`	2026-09-10	E	0	0	0	1	1
`c21p`	2026-09-10	E	0	0	0	125	125
`c30`	2026-09-10	E	0	0	0	3	1
`c30p`	2026-09-10	E	0	0	0	375	125
`c33`	2026-09-10	E	0	0	0	8	2
`c33p`	2026-09-10	E	0	0	0	40	10
`c36`	2026-09-10	E	0	0	0	3	2
`c36p`	2026-09-10	E	0	0	0	18	12
`c35`	2026-09-10	E	0	0	0	2	2
`c35p`	2026-09-10	E	0	0	0	27	27
`c34`	2026-09-10	E	0	0	0	4	2
`c34p`	2026-09-10	E	0	0	0	49	23
`c32`	2026-09-10	E	0	0	0	1	1
`c32p`	2026-09-10	E	0	0	0	4	4
`c39`	2026-09-10	E	0	0	0	11	2
`c39p`	2026-09-10	E	0	0	0	66	12
`s103_extern_variants`	2026-09-10	D,E,G	0	0	0	307	112
`s103_r19cast`	2026-09-10	E	0	0	0	10	6
`s103_r19castp`	2026-09-10	E	0	0	0	8	4
`c41`	2026-09-10	E	0	0	0	2	1
`c41p`	2026-09-10	E	0	0	0	27	17
`c38`	2026-09-10	E	0	0	0	2	2
`c38p`	2026-09-10	E	0	0	0	14	14
`c40`	2026-09-10	E	0	0	0	2	2
`c40p`	2026-09-10	E	0	0	0	12	12
`c42`	2026-09-10	E	0	0	0	3	2
`c42p`	2026-09-10	E	0	0	0	12	8
`c43`	2026-09-10	E	0	0	0	4	2
`c43x`	2026-09-10	E	0	0	0	24	12
`c46`	2026-09-10	E	0	0	0	14	0
`c46p`	2026-09-10	E	0	0	0	1,848	0
`s103_port`	2026-09-10	E	0	0	0	11	7
`c44`	2026-09-10	E	0	0	0	5	2
`c44p`	2026-09-10	E	0	0	0	37	14
`c45`	2026-09-10	E	0	0	0	4	2
`c45p`	2026-09-10	E	0	0	0	51	23
`s103_port2`	2026-09-10	E	0	0	0	4	2
`c37`	2026-09-10	E	0	0	0	1	1
`c37x`	2026-09-10	E	0	0	0	43	43
`c50`	2026-09-10	E	0	0	0	6	1
`c50p`	2026-09-10	E	0	0	0	774	129
`c49`	2026-09-10	E	0	0	0	1	0
`c49p`	2026-09-10	E	0	0	0	132	0
`c47`	2026-09-10	E	0	0	0	25	1
`c47p`	2026-09-10	E	0	0	0	3,325	133
`c52`	2026-09-10	E	0	0	0	4	4
`c52p`	2026-09-10	E	0	0	0	16	16
`c48`	2026-09-10	E	0	0	0	2	0
`c48p`	2026-09-10	E	0	0	0	264	0
`c54`	2026-09-10	E	0	0	0	2	1
`c54p`	2026-09-10	E	0	0	0	14	7
`s103_r26b`	2026-09-10	E	0	0	0	27	27
`s103_r26bp`	2026-09-10	E	0	0	0	22	22
`c55`	2026-09-10	E	0	0	0	6	2
`c55p`	2026-09-10	E	0	0	0	24	8
`c53`	2026-09-10	E	0	0	0	8	3
`c53p`	2026-09-10	E	0	0	0	58	23
`s103_port4`	2026-09-10	E	0	0	0	4	2
`s103_scrub`	2026-09-10	scrub	3	0	0	0	0
`c51`	2026-09-10	E	0	0	0	1	0
`c51p`	2026-09-10	E	0	0	0	133	0
`s104_all_part1`	2026-09-10	E	0	0	0	6	5
`s104_all_part1p`	2026-09-10	E	0	0	0	14	12
`s104_d2`	2026-09-10	E	0	0	0	40	8
`s104_d1`	2026-09-10	E	0	0	0	10	10
`s104_d3`	2026-09-10	E	0	0	0	4	4
`s104_d5`	2026-09-10	E	0	0	0	4	4
`s104_d6`	2026-09-10	E	0	0	0	24	8
`s104_d8`	2026-09-10	E	0	0	0	4	4
`s104_d9`	2026-09-10	E	0	0	0	6	6
`s104_d7`	2026-09-10	E	0	0	0	18	6
`s104_d4`	2026-09-10	E	0	0	0	4	4
`s104_d10`	2026-09-10	E	0	0	0	35	7
`s104_part2`	2026-09-10	E	0	0	0	50	38
`s104_part2p`	2026-09-10	E	0	0	0	56	38
`s104_d11`	2026-09-10	E	0	0	0	8	4
`s104_d12`	2026-09-10	E	0	0	0	20	4
`s104_d13`	2026-09-10	E	0	0	0	5	5
`s104_d15`	2026-09-10	E	0	0	0	12	4
`s104_d18`	2026-09-10	E	0	0	0	9	9
`s104_d14`	2026-09-10	E	0	0	0	9	3
`s104_d19`	2026-09-10	E	0	0	0	3	3
`s104_d16`	2026-09-10	E	0	0	0	10	5
`s104_d17`	2026-09-10	E	0	0	0	8	4
`s104_new5`	2026-09-10	E	0	0	0	5	4
`s104_r27`	2026-09-10	E	0	0	0	10	3
total			17,122	20,778	283	29,700	10,375

Generated by tools/lever_progress.py --render from .run/P36/census/lever_census.json and .run/P36/delever/ledger.jsonl; the series lives in docs/lever-progress.tsv (R75: published numbers are generated, never typed).

3. How they got in

Nobody sat down to write 34,000 levers. They arrived one bank at a time, over five phases, each time as the cheapest way past a real wall:

Phase 18 researched gcc 2.7.2's register allocator and produced the pin toolkit (cookbook §17). It worked: the wave close-rate went 33% → 56% → 90% in one phase. Pins were the difference between a wave that banked and a wave that did not.
Phases 19–29, the family campaign, scaled that: one cracked exemplar remapped across up to 134 overlays, and every lever in the exemplar was copied with it. This is why the count is in the tens of thousands and the distinct count is in the hundreds — 12,578 bodies carry class A/B sites, but only 1,758 distinct texts.
Phase 23's local-model tier and Phase 30–31's autonomous lanes drafted at a rate no human reviewed line by line; a pin that made the byte gate go green was, correctly for those phases, a win.
§501-E (Phase 32) then replaced pins with launders on some functions — trading one lever for another. That recipe is explicitly out of bounds in Phase 36.

Two facts about that history matter for the argument below. First, the knowledge needed to remove a lever did not exist when the lever was added — the §31 codegen map (Phase 23), the allocation-order reading (alloc_table.py, Phase 32) and the §501-P/Q/R producer censuses all came later. Second, Phase 32 measured the thing that makes this a debt rather than a cost: on the last four functions of the frontier, every pin came off byte-identical once the source shape was right (R73). A pin was rarely load-bearing. It was a shortcut around finding the shape.

4. How they come off — the ladder, and what each rung is worth

rung	what it does	cost	measured yield
A strip-all	remove every lever in a body at once, compile, compare	1 compile	see the campaign table above
B greedy	re-add sites one at a time to find the minimal needed set	≤ sites+1 compiles	the residue after A
C exemplar/replay	a multi-copy class judged once, replayed to every copy	1 compile per copy	most of the fleet's copies
R recipes	the cookbook's byte-neutral shape recipes, mechanically (R2 declaration order · R3 initializer split · R4 one declaration moved through the run · R5 operand order of one commutative operator · R6 a single-set temp inlined at its use · R7 one statement wrapped in a block)	1 compile per candidate	134 of 134 bodies in 6.0 min, 3,243 compiles (batch `r1`)
D permuter	decomp-permuter seeded with the lever-free body against the target bytes	~12 min per exemplar	5 of 16 exemplars, 665 of 2,131 bodies behind them, 0.69 h
E agents	one agent per surviving class exemplar, with the pack	tokens	Phase 36 T7

RUNG R IS A REPLICATION ENGINE, NOT A DISCOVERY ENGINE — measured, S99. On a class whose shape rung D had already found it closed 134 of 134 bodies in 6 minutes. On 300 residue bodies where nobody had found the shape yet it closed 0 of 300 at --cap 40 (12,110 compiles, 4.6 min) and 0 of 300 at --cap 400 (17,140 compiles, 6.0 min)`. Two things make that a real result rather than a budget problem: the instrument was checked on one body by hand (every candidate COMPILES and returns DIFFERS — nothing was erroring out silently), and 17,140 compiles over 300 bodies is ~57 candidates each, so the cap was never the binding constraint — ten times the depth produced 42% more candidates and closed nothing. The recipe rung banks a KNOWN shape across a class for free; it has nothing to say about a shape that is not in its list. Growing it means finding more shapes (rung D, then agents), and harvesting each one back into the rung so it sweeps the population for free.

The two rungs feed each other. Rung D's wins are not exotic: each is a small nameable source shape — a statement wrapped in a block (flag = 0; → do { flag = 0; } while (0);), a single-set temp inlined at its use. Every one of them became a rung-R recipe the same session, and rung R then banks the whole class mechanically, as a one-line diff in the real source, where banking the permuter's own output would paste a pycparser-reprinted body into a phase whose entire purpose is readability. Rung D is the scout; rung R is the harvest.

What the residue looks like. After rungs A–C the survivors split by the starting distance of the lever-free body from the target, not by how many sites they carry: exemplars 8–29 mismatched instructions away closed (5.9 s to 651 s); those 70–276 away did not close in 12 minutes, and every one of those is a body where removing a hand-placed instruction lever changed the instruction count and shifted everything after it. None is a wall — they improved 78→9, 52→3, 50→3, 37→2 — they are seeds for a longer run or for an agent.

An instrument warning that cost two campaigns (cookbook §454): a search harness whose target is assembled from a disassembly listing is not measuring your code. objdump prints the pseudo-instruction move for addu rX,rY,$zero and GAS assembles move as or; a listing's %hi/%lo pairs come back resolved with no relocation. The scorer read 28 for a body that was byte-identical, so score 0 was unreachable and two campaigns reported "0 of 16" about a population that was fine. Seed any byte search with a body that already matches and require base score 0 before believing a yield.

5. The question that outlives the project: prevent, or clean up at the end?

The honest answer is neither extreme, and the evidence points at a specific middle.

What the numbers say. The mechanical rungs (A/B/C) removed or rewrote 21,061 sites across 17,119 bodies — the campaign table's own totals — against 33,957 still standing: 38% of the class A/B population came off with no understanding at all, by strip it, compile, compare. Those levers were never load-bearing. They were speculative, added by a drafter that had no cost signal for adding one, and a single compile at bank time would have refused them. That is the strongest measured claim in this document: more than a third of the debt would never have existed if banking a function had asked "does it still match without this?" once.

What the history says against blanket prevention. The pin toolkit is why Phase 18's waves closed at all, and the knowledge to replace a pin with the right source shape did not exist until Phases 23–32. A rule of "no levers, ever" adopted in Phase 18 would have stalled the project at ~56% for months, in exchange for a debt that a later phase paid off in weeks with better tools. Deferring was not obviously wrong; deferring silently was.

The rule we would actually adopt from day one — and the one the day-one kit should carry:

A lever is allowed, and it is a marked, ledgered debt from the moment it is banked. One comment at the bank site naming the class and what it forces (// !FAKE: pin $16 — without it gcc allocates x to $17), and a census that counts them. Phase 36 had to re-derive that reason for 34,091 sites, function by function, years after the fact; writing it once at bank time is nearly free and is the difference between a debt and an archaeology project.
The bank-time trial: compile the body once without the lever before accepting it. One compile. It would have refused ~37% of the population at the moment of creation, when the context was hot.
Publish the count as a first-class metric next to the match percentage. A number nobody publishes is a number nobody pays down. This project's lever count was invisible until the phase that removed them.
Levers get the harvest → toolify treatment, exactly like idioms. When a wave learns the shape that replaces a lever class, that shape becomes a mechanical recipe and sweeps the banked population — instead of the lever propagating with every family remap (which is how 1,758 distinct bodies became 12,578).
Do NOT block a phase on lever-freedom. Keep the byte gate as the only gate; let the marker and the count carry the debt forward. A cleanup phase with mature tooling is genuinely cheap — rung A/B is a few hours of compute for a third of the population, and rung R banks a 134-copy class in six minutes.

In one line for the kit: ban the silence, not the lever.

6. For the wiki and the kit

Wiki page ("Levers") — sections 1, 2 and 5 of this document, plus the current chart. The count belongs beside the match percentage on the progress page: a project that is 100% matched and 34,091 levers deep is not finished, and saying so plainly is the difference between this decomp and the ones the community complains about (docs/gen3-standards.md).
decomp-architect/ — section 5's five rules, as a Phase-1 kernel (a lever is a marked debt; the bank-time trial; the published count; harvest→toolify for levers; never block the byte gate on it) with this document's measured numbers as the provenance. The taxonomy in section 1 transfers unchanged to any gcc-era PS1 decomp.
Parked for the endgame (Drew, 2026-09-09): train a gcc 2.7.2 LoRA on the final clean asm/C pairs and release it for other decompilations to use when cracking. Not now, and not on today's corpus: our 363,214 matched pairs are (asm → C-with-levers), so training on them teaches a model to PRODUCE pins. The corpus worth releasing is the one this phase creates — lever-free C beside its bytes — which is another reason to finish the removal before the project ships its dataset.
The story — the arc is: a toolkit that unlocked the project (P18) → a family engine that multiplied it 134× (P19–29) → a phase that measured the debt for the first time (P36 T1) → mechanical removal of a third of it (T4) → a scout-and-harvest loop for the rest (T6) → zero (T7). The interesting beat is not the cleanup; it is that the shortcut that made the project possible was also the thing it had to spend a whole phase undoing, and that both were the right call at the time.

7. Maintenance

Run at the close of every task that changes the count, and at every phase close:

.venv/bin/python tools/lever_census.py --sites --check -j 16     # the count, and 0 UNMARKED
.venv/bin/python tools/lever_progress.py --snapshot "T6 r1"      # appends the milestone row, re-renders §2

tools/lever_progress.py --check fails when the series' last row is not this tree — a stale series is a wrong chart.

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