The generic_nesting chain with a method REQUIRED by the constraint interface and called recursively through the witnesses (`first.eval() + second.eval()`), so overload resolution and inheritance-witness lookup run at every nesting level instead of only type checking the aliases. Same depth axis as generic_nesting, much steeper constant: measured ~2.9x per level when added (2026-07), vs ~3-4x per level from substitution alone but starting an order of magnitude higher at equal depth. Scaling null: each level adds O(1) declarations and one call site, so ideal front-end cost is O(n). The ladder tops out below generic_nesting's because the per-level multiplier bites sooner.
bucket: sema · mode: module · flags: (none)
compileInner split into phase buckets (named leaves + (self) residuals) stacked across the sweep sizes — the top edge is compileInner, so you can see which phase drives the scaling.
floor-subtracted power-law fit (t − floor) = a·Nk; floor = the minimal workload (fixed per-compile cost), k the global exponent, top-2× the local high-end doubling ratio.
| N range | floor (ms) | k (work) | fit R² | t(Nmin) | t(Nmax) | top-2× |
|---|---|---|---|---|---|---|
| 8–14 | 9 | 5.53 | 0.964 | 11 | 57 | 2.57× |
compileInner grows by 46 ms across the sweep; the mutually-exclusive phase buckets below partition that growth exactly (no nested-timer double counting). × lin is the same metric as the top-level panels, per bucket: the end point vs a linear expectation anchored to the bucket's share of the minimal floor and fitted on the low-N half — 1.0 = grew exactly linearly, >1 bends up. The super-linearity lives where × lin (and k) are red.
| bucket | t@N=8 | t@N=14 | Δ ms | share | × lin | ∝Nk |
|---|---|---|---|---|---|---|
| generateIR | 1 | 47 | +46 | 100% | 12.90× | 6.96 |
Near-constant (≤2% of growth each): SemanticChecking (8→8 ms), generateOutput (self) (1→1 ms), parseTranslationUnit (0→0 ms), frontEndExecute (self) (0→0 ms), compileInner (self) (0→0 ms).
| N | compileInner | SemanticChecking | frontEndExecute |
|---|---|---|---|
| 8 | 11 | 8 | 10 |
| 10 | 13 | 8 | 12 |
| 12 | 22 | 8 | 21 |
| 14 | 57 | 8 | 56 |