ATOL and RTOL should probably be configurable per-test. Ideally, we also make the defaults as small as possible and override it on tests that need it.

[psiddh]

ATOL and RTOL should probably be configurable per-test. Ideally, we also make the defaults as small as possible and override it on tests that need it.

Originally posted by @rascani in #18311 (comment)

[psiddh]

Make BundleIO ATOL/RTOL configurable per-test

▎ Title: Support per-test ATOL/RTOL for Cortex-M BundleIO verification

▎ Currently ET_ATOL and ET_RTOL are set globally at build time via --extra_build_flags="-DET_ATOL=5.0 -DET_RTOL=1.0" in build_test_runner.sh.
This means every test using the runner gets the same relaxed tolerances, even if some models could pass with tighter bounds.

▎ Proposal:
▎ - Make the defaults as tight as possible (e.g. ATOL=1e-3, RTOL=1e-3)
▎ - Allow per-test override via runtime args (e.g. -atol 5.0 -rtol 1.0) or BundleIO metadata embedded in the .bpte
▎ - Update test_cortex_m_e2e.sh to pass model-specific tolerances

▎ This enables catching real numerical regressions on models that should be precise while still allowing relaxed tolerance for int8 quantized
models like mv2/mv3.