// be a power of 2 (because it is a single bit) or 0 (if the original value is 0).
// In all of these rules we use a rightmost bit calculation to determine one operand
// for the addition or subtraction. We then just need to calculate if the other
// operand is a valid power of 2 before we can match the rule.
//
// Notes:
//   - the generic rules have already matched single powers of two so we ignore them here

//
// Note, y is always non-negative.
//
// Note, ISELZ is intentionally not used in lower. Where possible, ISEL is converted to ISELZ in late lower
// after all the ISEL folding rules have been exercised.

((Rsh64U|Lsh64)x64 <t> x y)  => (ISEL [0] (S(R|L)D <t> x y) (MOVDconst [0])        (CMPUconst y [64]))
((Rsh64U|Lsh64)x32 <t> x y)  => (ISEL [0] (S(R|L)D <t> x y) (MOVDconst [0])        (CMPWUconst y [64]))

// shifts
// hardware instruction uses only the low 6 bits of the shift
// we compare to 64 to ensure Go semantics for large shifts
// Rules about rotates with non-const shift are based on the following rules,
// if the following rules change, please also modify the rules based on them.

// check shiftIsBounded first, if shift value is proved to be valid then we
// can do the shift directly.
// left shift

Anže Sodja <******@****.***> 1717576978 +0200

rules:
- destination: apimachinery
  branches:
  - name: master
    source:
      branch: master
      dirs:
      - staging/src/k8s.io/apimachinery
  - name: release-1.27
    go: 1.21.11
    source:
      branch: release-1.27
      dirs:
      - staging/src/k8s.io/apimachinery
  - name: release-1.28
    go: 1.21.11
    source:
      branch: release-1.28
      dirs:
      - staging/src/k8s.io/apimachinery

Joel Sing <******@****.***> 1707360850 +1100

Guoqi Chen <******@****.***> 1692152533 +0800

Junxian Zhu <******@****.***> 1683865731 +0800

Junxian Zhu <******@****.***> 1685079225 +0800

Ludi Rehak <******@****.***> 1690680342 -0700