!sum
- go: SetElem
  commutative: "false"
  extension: "AVX.*"
  documentation: !string |-
    // SetElem sets a single constant-indexed element's value.
- go: GetElem
  commutative: "false"
  extension: "AVX.*"
  documentation: !string |-
    // GetElem retrieves a single constant-indexed element's value.