Because of the nature of memory systems and instruction-set designs, the best generic routine to copy memory is rarely as fast as code written to copy a particular length.

由于内存系统和指令集设计的特性，用于复制内存的最佳通用例程的执行速度通常比用于复制特定长度的代码慢。

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The PowerPC uses a load/store (also called RISC) instruction set, which means that the only time it accesses main memory is for loading into registers or copying a register to memory.

PowerPC 使用了加载/存储（也成为 RISC）指令集，这意味着访问主存的惟一 时机就是将内存加载到寄存器或将寄存器中的内容复制到内存中时。

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Memory is a function of direct access to central processing instruction and data memory.

内存是中央处理机能直接存取指令和数据的存储器。

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That program counter points to some location in memory typically to the first instruction in the sequence.

程序计数器指示存储器当中的某些位置,尤其是指示序列中的第一个指令。

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