Hans Goudey
d2f0cb6745
On GCC, the loops created by `BLI_VEC_OP_IMPL` were not always unrolled, leading to branching. For `attribute_math::mix4<float3>`, this lead to a significant performance regression compared to its older `interp_v3_v3v3v3v3` counterpart. Instead of a using macros to create the for loops, use variadic templates to manually unroll them. The compiler might do it anyway (I didn't observe any effect on Clang in my tests), but there should be no reason not to unroll these small loops, and making it explicit and removing use of macros seems better. On a Ryzen 3700x, this commits doubles the performance of Catmull Rom curve position evaluation (from 18-19ms to around 9-10ms). Differential Revision: https://developer.blender.org/D16136