// First the tiles needed for the tree hash.
	th, err := HashFromTile(tiles[stxTileOrder[len(stx)-1]], data[stxTileOrder[len(stx)-1]], stx[len(stx)-1])
	if err != nil {
		return nil, err
	}
	for i := len(stx) - 2; i >= 0; i-- {
		h, err := HashFromTile(tiles[stxTileOrder[i]], data[stxTileOrder[i]], stx[i])
		if err != nil {
			return nil, err
		}
		th = NodeHash(h, th)
	}
	if th != r.tree.Hash {

	LDP	1*16(a_ptr), (x2, x3)
	p256AddInline
	STx(m)

	LDx(z1in)
	LDy(y1in)
	CALL	p256MulInternal<>(SB)
	p256MulBy2Inline
	STx(z3out)

	LDy(x1in)
	LDx(zsqr)
	CALL	p256SubInternal<>(SB)
	LDy(m)
	CALL	p256MulInternal<>(SB)

	// Multiply by 3
	p256MulBy2Inline
	p256AddInline
	STx(m)

	LDy(y1in)
	p256MulBy2Inline