这句话什么意思?LOBYTE?LOWORD?HIBYTE?HIWORD?

adjacency

DWORD dwReverseIP = 0;
DWORD dwIP;
dwReverseIP = (LOBYTE(LOWORD(dwIP)) << 24) | (HIBYTE(LOWORD(dwIP)) << 16) | (LOBYTE(HIWORD(dwIP)) << 8) | (HIBYTE(HIWORD(dwIP)));

(LOBYTE(LOWORD(dwIP)) << 24)
先取dwIP的低16位字节(共8*16位字位bit么?)
再从刚才的8*16位字位中取最低（最右边）那个字节(8字位bit么?)
这8字位再向左移24位么?
左移24位!结果会是0吧?

让诸位见笑了.
大侠赐教.