You can nest for loops by placing one loop within another. 可以将一个循环放在另一个循环内以嵌套。
The technologies of automatic parallelizing currently focus on the loop nest, and the array in the loop is the object when optimizing communication. 目前的并行化技术主要针对循环级并行,循环中的数组是进行通信优化的主要对象。