1498985 - Build encoding_rs and simd crates with opt_level=3

Status: NEW

(Core :: Internationalization, enhancement, P3)

Description

[Henri Sivonen (:hsivonen) (temporarily away from Bugzilla)]

Bug 1413285 indicates that we're going to get the ability to upgrade specific crates from opt_level=2 to opt_level=3.

For encoding_rs, investigating perf regressions at opt_level=2 has consumed disproporionate effort. The latest is that switching from the simd crate to packed_simd is performance-neutral at opt_level=3 but regressed the perf of some things at opt_level=2.

It would help my productivity if we could build encoding_rs (and simd) at opt_level=3 and I could stop worrying about unwanted perf effects at opt_level=2.