}

// Compress mask and shift into single value of the form
// me | mb<<8 | rotate<<16 | nbits<<24 where me and mb can
// be used to regenerate the input mask.
func encodePPC64RotateMask(rotate, mask, nbits int64) int64 {
	var mb, me, mbn, men int

	// Determine boundaries and then decode them
	if mask == 0 || ^mask == 0 || rotate >= nbits {

(ANDconst [m] (ROTLWconst [r] x)) && isPPC64WordRotateMask(m) => (RLWINM [encodePPC64RotateMask(r,m,32)] x)
(AND (MOVDconst [m]) (ROTLWconst [r] x)) && isPPC64WordRotateMask(m) => (RLWINM [encodePPC64RotateMask(r,m,32)] x)
(ANDconst [m] (ROTLW x r)) && isPPC64WordRotateMask(m) => (RLWNM [encodePPC64RotateMask(0,m,32)] x r)
(AND (MOVDconst [m]) (ROTLW x r)) && isPPC64WordRotateMask(m) => (RLWNM [encodePPC64RotateMask(0,m,32)] x r)