Cesium Native (and I think some of the deps like draco) use glm. glm is significantly faster with SIMD, but according to the glm manual:
GLM provides some SIMD optimizations based on compiler intrinsics. These optimizations will be automatically thanks to compiler arguments when
GLM_FORCE_INTRINSICSis defined before including GLM files.
This implies that omitting GLM_FORCE_INTRINSICS before glm includes means SIMD won’t be used (it’s a bit confusing since they have another define for forcing SIMD to off, but the wording in the manual is consistent with the above). I didn’t see this define in the Cesium source files where glm headers are included, and I didn’t see it in the Cesium cmake configuration (possible I missed it…). Seems to me it would be best to have a configuration that supports it for systems that have SIMD (which is virtually all of them)