Commit 8b9743eb40 already made Blender be compiled with SSE4.2 flags
on x64 architecture, which kicked in the SSE4 code paths in
BLI_math_interp functions.
Which made them faster, e.g. in VSE on Windows/Ryzen5950X, scaling
up an image to 4K resolution:
- Bilinear 5.8ms -> 5.3ms
- Cubic Mitchell 16.3ms -> 15.7ms
This change removes the now-unneeded SSE pre-SSE4 code paths for
_mm_floor_ps, _mm_min_epi32 and _mm_max_epi32 emulation.
Additionally, including BLI_simd.h on SSE4 platform now includes
the necessary SSE4 intrinsics header.
Pull Request: https://projects.blender.org/blender/blender/pulls/120583
e2e6b977a6