A single moderately complex shader. Compiled to multiple targets by the harness (same source, varying -target) to isolate generateOutput cost. ``n`` scales the amount of straight-line math the backend must emit. Scaling null: n scales op count and the emitted output is O(n); ideal codegen cost is O(n).
bucket: codegen_source · mode: target · flags: -target hlsl -entry computeMain
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× |
|---|---|---|---|---|---|---|
| 100–800 | 14 | 1.89 | 0.989 | 91 | 4043 | 5.10× |
compileInner grows by 3952 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=100 | t@N=800 | Δ ms | share | × lin | ∝Nk |
|---|---|---|---|---|---|---|
| emitEntryPointsSourceFromIR | 32 | 1985 | +1952 | 49% | 5.32× | 1.97 |
| legalizeResourceTypes | 9 | 798 | +789 | 20% | 6.53× | 2.16 |
| legalizeExistentialTypeLayout | 9 | 765 | +755 | 19% | 6.35× | 2.13 |
| simplifyIR | 6 | 282 | +275 | 7% | 4.17× | 1.84 |
Near-constant (≤2% of growth each): specializeModule (5→77 ms), SemanticChecking (19→73 ms), generateIR (8→57 ms), linkIR (1→3 ms), parseTranslationUnit (0→2 ms), frontEndExecute (self) (1→1 ms), performMandatoryEarlyInlining (0→1 ms), performForceInlining (0→0 ms), unrollLoopsInModule (0→0 ms), compileInner (self) (1→0 ms).
| N | compileInner | emitEntryPointsSourceFromIR | generateOutput |
|---|---|---|---|
| 100 | 91 | 63 | 63 |
| 200 | 233 | 196 | 197 |
| 400 | 793 | 740 | 741 |
| 800 | 4043 | 3910 | 3911 |