stack pointer

基本解釋

So in this instruction, $sp is the stack pointer (it's an alias for $1).
所以在這個指令中，$sp 是堆棧指針（它是 $1 的別名）。
The stack is coordinated with a stack pointer that keeps track of storage and retrieval of each byte or word of information in the stack.
棧和一個棧指針配合工作，棧指針隨時指示要存取的每個字或字節(jié)信息在棧中的位置。
This simple design, possible because the data obeys strict LIFO order, means that no complex data structure is needed to track stack contents - a simple pointer to the top of the stack will do.
這種簡單的設(shè)計(jì)，很有可能是考慮到數(shù)據(jù)操作都符合后進(jìn)先出（LIFO ）規(guī)則，這意味著訪問棧的內(nèi)容并不需要復(fù)雜的數(shù)據(jù)結(jié)構(gòu)，一個簡單的棧頂指針就能搞定一切。