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Drew T
5d9616739a
Acted on T46's verdict (K8/RC-4 local-alloc tying, lever = C-level lifetime shaping) instead of the
refuted allocation/permuter framings.
THE LEVER WORKS. Cluster B is `q = (Trk *)((u8 *)e + 0x3C)` landing in $a2 where the target uses $a0,
because arg0's last use (`self = arg0`) sat BELOW q's birth, keeping $a0 live so K3 first-fit pushed
q to the next free reg. Moving `self = arg0` above q's birth ELIMINATES cluster B in both placements
tried -- byte-measured:
baseline A=4 B=2 C=2 D=5 -> 13
(a) self at top A=7 B=0 C=2 D=5 -> 14
(b) self after e A=7 B=0 C=2 D=5 -> 14
BUT IT COSTS 3 POSITIONS IN A, AND THE COUPLING IS ALREADY DOCUMENTED in the draft's own header:
cluster A is a sched2 LUID tie COUPLED to lever 3 -- st1 must stay a decl-initializer (moving it into
the body forfeits the update_equiv_regs live-length doubling at local-alloc.c:1064, allocno priority
explodes, callee-saved bank rotates, frame 0x40->0x48, measured over 12 permutations), while st2/ext
must sit in the body after the index chain AND the `self = arg0` copy to reproduce the target's
save/init interleave. Moving `self = arg0` is exactly the statement that interleave is anchored on.
VERDICT: a THIRD two-knobs-one-screw in this function. st1's LUID is pinned by allocno priority ->
pins the save/init interleave (A) -> pins where `self = arg0` may sit -> decides whether q gets $a0
(B). Any future attempt must optimise A and B TOGETHER; fixing either alone is provably a wash.
Not banked, nothing regressed (draft-side only, tree clean). Cluster B has moved from an unexplained
register 2-swap to solved-but-priced-at-3-positions-in-A. Variants at .run/near6/g734_{a,b}.c.
Effort ledger recorded: Fable5 pass, wave agent (~2.6M tok, 217->13), 32-min permuter (flat),
reg_renumber oracle (framing refuted), this grind. 51,198 ins; five tiers have now bounced.
phase-ends/ — the living record
PhaseEnd_Phase[N].md— written at each phase boundary (format defined inPROJECT_CONTEXT.md). Append-only history: build log, deviations, commit message, rules added, changelog. Never deleted.CURRENT_PHASE.md— the in-phase autonomous log: approved phase plan, per-task checkboxes, current task pointer, blockers. Created at phase start, updated after every task, absorbed into the PhaseEnd file and deleted at phase close. This is the crash/compaction recovery point.- Sessions read
PROJECT_CONTEXT.md, then everyPhaseEnd_*.mdin numeric order, thenCURRENT_PHASE.md(if present) — in that order, every session.