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Float parity policy

This project targets high-fidelity replay and deterministic simulation parity. For gameplay code, float behavior is part of the contract.

Default rule

In deterministic gameplay paths, prefer native float32 fidelity over source readability:

  • Keep decompiled float constants when they influence simulation outcomes.
  • Keep native operation ordering when it changes rounding boundaries.
  • Keep float32 store/truncation points where native stores to float.

Do not auto-normalize literals like 0.6000000238418579 to 0.6 in parity critical code unless parity evidence shows the change is behavior-neutral.

Why

Small float deltas can reorder branch decisions and collision outcomes, then amplify into RNG drift and deterministic divergence over long runs.

Allowed normalization

Literal simplification is acceptable when all of the following are true:

  1. The path is non-deterministic or presentation-only (not gameplay simulation).
  2. Differential evidence (capture + verifier) shows no behavior change.
  3. A test or session note records that evidence.

If any condition is missing, keep the native-looking float behavior.

Implementation guidance

  • Use float32 helpers and explicit store-boundary mirrors in parity-sensitive code.
  • Prefer parity captures and focused traces over intuitive “cleanup”.
  • Document any intentional float deviation in docs/frida/differential-sessions.md.