!sum
# Polynomial (carryless) multiply long, P64 variant (2D→1Q).
- go: carrylessMultiplyWidenLo
  asm: VPMULL
  hiHalfAsm: VPMULL2
  in:
  - go: Uint64x2
  - go: Uint64x2
  out:
  - go: Uint64x2