sim-lib-interference-compute

Normalized tile-local f32 Tensor lowering for coherent scalar-wave fields.

The lowering preserves the core's homogeneous, isotropic, three-dimensional scalar free-field scope. It does not add polarization, impedance, interfaces, obstacles, or diffraction. Amplitude-squared differential metrics are normalized observables, not physical intensity, power, or energy.

The crate preflights a complete interference problem and physical sampling plane before submitting any work. It partitions the plane under explicit phase, element, segment, tensor-byte, and result-byte limits. Host f64 geometry supplies a phase anchor and gain at each tile center; device-visible Tensors contain only bounded offsets from that center.

Point sources use the cancellation-safe normalized distance residual

delta = (2*a + b*rho) / (sqrt(1 + 2*a*rho + b*rho*rho) + 1)

and every source uses host angle addition so executor sin and cos receive only residual phase in [-pi, pi]. Contributions are accumulated with a deterministic pairwise tree. The lowering submits only the canonical open Tensor operations add, sub, mul, div, sqrt, exp, sin, and cos; it owns no executor, device API, shader, queue, or storage type.

LoweringPlan::preflight rejects unsupported operators and dtype, invalid shapes, singular point samples, samples behind forward planes, unstable denominators, allocation excess, and phase/error-budget excess before the captured executor receives its first request.

solve_dense_f32_cpu executes that exact lowering through the canonical CPU TensorExecutor and assembles its tiles into a finite row-major DenseF32Field. DenseExecutionEvidence retains the executor, tile and segment counts, flushes, admitted phase limit, predicted tile-radius bound, observed maximum residual phase, and predicted geometry and arithmetic errors.

compare_dense_to_reference applies one published fixed comparison contract:

compare_materialized_to_reference applies that identical report to modeled and physical-provider results after the two explicit final component materializations. HardwareEvidenceReport binds the result to a sanitized adapter/profile id, phase bound, tile and segment counts, lifecycle counters, and exactly 100 same-profile repeats. A measured pass requires bit-identical component planes across all repeats in addition to the differential tolerances. not-measured is an explicit result and can never satisfy the hardware gate.

The checked tilted-plane sweep records why normalized reduction is required:

Both phase bounds remain below pi. Normalized error stays bounded while the falsified absolute-f32 formulation grows every decade and is more than 8,000 times worse at 1000 m.

InterferenceComputeLib composes this lowering with the runtime's narrow StudySolver seam. A TensorSite binds its executor in the active child environment; only then does TensorStudySolver supersede the reference CPU solver. Missing executors, operations, f32 support, crossover work, or a single-resident-output layout select CPU before submission. Once a provider is selected, a failure is returned without a CPU restart.

The resident adapter uploads the three immutable coordinate planes once, chains every intermediate at the selected site, and returns real and imaginary as the final resident Tensors. StudyEvidence carries the provider, adapter/profile, upload/submission/segment counts, zero intermediate materializations, two final component materializations, and fixed f32 tolerances. Resident storage owns synchronized observation caching, so repeated host projection does not repeat readback.

The checked provider matrix exercises the same f64 oracle, dense f32 baseline, modeled site, and opt-in wgpu site over attenuated multi-segment fields, long-world normalized phase, exact cancellation, and measured crossover edges. Explicit wgpu absence exports no site. The automatic provider's auto/cpu decision is recognized before the first Tensor submission and retained as ProviderCpuChoice; accepted provider failures still never restart on CPU.

Set SIM_INTERFERENCE_WGPU_PHYSICAL=1 only when a probe-backed adapter should be measured. Headless default tests emit the bounded not-measured recipe evidence without probing hardware or turning absence into a passing hardware claim.