- improve cpu dispatching calls to allow more SIMD extentions
    (SSE4.1, AVX2, VSX)
  - wide universal intrinsics
  - replace dummy v_expand with v_expand_low
  - replace v_expand + v_mul_wrap with v_mul_expand for product accumulate operations
  - use FMA for accumulate operations
  - add mask and more types to accumulate's performance tests