在我当时正在使用的计算机上，浮点数占用了单个36位寄存器。一个双占用两个36位寄存器。硬件具有单独的指令，用于操作该编号的1个寄存器和2个寄存器版本。我不确定这是术语的来源，但有可能。

On the machine I was working on at the time, a float occupied a single 36 bit register. A double occupied two 36 bit registers. The hardware had separate instructions for operating on the 1 register and 2 register versions of the number. I don't know for certain that that's where the terminology came from, but it's possible.