_XMUL
_XMUL(zh, zl, h, 0, ph, pl);
_XMUL(zh, zl, h, 0, ph, pl);
_XMUL(zh, zl, h, 0, ph, pl);
_XMUL(zh, zl, h, 0, ph, pl);
_XMUL(zh, zl, h, 0, ph, pl);
_XMUL(zh, zl, h, 0, ph, pl);
_XMUL(zh, zl, -h, 0, ph, pl);