For vecLIb Accelerate uses undocumented AMX coprocessor. Libraries that also are accelerated:
vImage — high level image processing, converting between formats, image manipulation.
BLAS — industry standard for linear algebra
BNNS — running and training neural networks
vDSP — digital signal processing. Fourier transformations, convolution, image processing or any signal really including audio.
LAPACK — high level linear algebra functions, for solving linear equations.