On macOS 27.2 (rustc 1.98) one of the 404 pinned simulation hashes,
CC Mr. Mercury at non-default settings, 32 bpc, t = 2.2 s, came out
different. The reporter rendered every case at the commit that pinned
the hashes and at current main on that machine, and the frames were
byte-identical. So the code didn't change: the platform's libm did
(the hashes are exact f32 bits through sin, cos and powf). The test
now also accepts listed per-case libm variants, with that hash as the
first, and every other case stays exact. Its docs say how to tell a
libm difference from a code change.
Test: libm_variants_are_accepted_for_their_case_only (sim_golden; runs
on every platform).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>