fp-hw-survey capture: Apple Silicon (M-series, arm64/macOS)

[MikeGrier]

Capture native FP behavior on Apple Silicon (M1/M2/M3/M4, aarch64 / macOS) with crates/fp-hw-survey.

Steps

cargo build --release -p fp-hw-survey
./target/release/fp-hw-survey info        # confirm CPU brand + features (expect fp16; rpres/afp if present)
./target/release/fp-hw-survey selftest    # must pass
./target/release/fp-hw-survey capture --label m<N>-mac

What to attach to this issue

• The info output (CPU brand + detected features).
• The selftest result (must be clean — capture refuses to write otherwise).
• The one-line NDJSON header from the capture (durable provenance: cpu / os / features / date).
• The capture-*.ndjson file itself (attachment or link).

Notes

• fp16 is expected on all shipping M-series; rpres/afp recorded if detected.
• Intra-ARMv8 estimate ops (frecpe/frsqrte/frecpx/fmulx) are predicted to be bit-identical with other ARMv8 parts — a zero-divergence merge against them is the expected, informative result.

Part of the FP hardware survey fleet-capture campaign.