SN-0810 已核对来源，附原文与上下文。
MinGW 仍然只有老当益壮的稳定版 3.4.5。他们没多少理由去更新它。
MinGW still only has good old stable 3.4.5. There's not much reason for them to update it.
我看 3.4.5 编译出的 SHA 反汇编时，完全看不出有任何改进余地。我无法想象还能从里面再挤出 8%。有没有可能 Windows 本身就有 8% 的额外开销？不做系统调用之类的，纯粹是忙于计算的代码，任务切换和其他管理性操作能吃掉这么多吗？
When I looked at the 3.4.5 compiled SHA disassembly, I couldn't see any room for improvement at all. I can't imagine how 8% more could be squeezed out of it. Is it possible Windows could have 8% more overhead? Not making system calls or anything, just plain busy computational code, could task switching and other housekeeping operations take away that much?
