Wondering about the equivalent of cuBLAS for OpenCL? CLBlast is the nearest match, clBLAS is also available but not as performant. The “t” is for tuned.
20200618/https://github.com/CNugteren/CLBlast
20200618/https://github.com/clMathLibraries/clBLAS
Vulkan is not yet available for Raspberry Pi 4, but OpenGL ES 3.1 Compute Shaders are available, so you can use this in the intermin.
20200618/https://blogs.igalia.com/itoral/2020/01/17/raspberry-pi-4-v3d-driver-gets-opengl-es-3-1-conformance/