(MOVBZreg (SRWconst x [s])) && mergePPC64AndSrwi(0xFF,s) != 0 => (RLWINM [mergePPC64AndSrwi(0xFF,s)] x)
(MOVBZreg (RLWINM [r] y)) && mergePPC64AndRlwinm(0xFF,r) != 0 => (RLWINM [mergePPC64AndRlwinm(0xFF,r)] y)
(MOVHZreg (RLWINM [r] y)) && mergePPC64AndRlwinm(0xFFFF,r) != 0 => (RLWINM [mergePPC64AndRlwinm(0xFFFF,r)] y)
(MOVWZreg (RLWINM [r] y)) && mergePPC64MovwzregRlwinm(r) != 0 => (RLWINM [mergePPC64MovwzregRlwinm(r)] y)

// Combine (ANDconst [m] (SRWconst [s])) into (RLWINM [y]) or return 0
func mergePPC64AndSrwi(m, s int64) int64 {
	mask := mergePPC64RShiftMask(m, s, 32)
	if !isPPC64WordRotateMask(mask) {
		return 0
	}
	return encodePPC64RotateMask((32-s)&31, mask, 32)
}

// Test if a word shift right feeding into a CLRLSLDI can be merged into RLWINM.
// Return the encoded RLWINM constant, or 0 if they cannot be merged.

		p = s.Prog(obj.ANOP)
		pbover.To.SetTarget(p)

	case ssa.OpPPC64CLRLSLWI:
		r := v.Reg()
		r1 := v.Args[0].Reg()
		shifts := v.AuxInt
		p := s.Prog(v.Op.Asm())
		// clrlslwi ra,rs,mb,sh will become rlwinm ra,rs,sh,mb-sh,31-sh as described in ISA
		p.From = obj.Addr{Type: obj.TYPE_CONST, Offset: ssa.GetPPC64Shiftmb(shifts)}
		p.AddRestSourceConst(ssa.GetPPC64Shiftsh(shifts))
		p.Reg = r1
		p.To.Type = obj.TYPE_REG