multithreading - 什么是FIFO存储缓冲区中的本地旁路？

Question

我正在阅读A Primer on Memory Consistency and Cache Coherence书，发现了这个(pp19):

Load-store and store-load reordering. Out-of-order cores may also reorder loads and stores (to different addresses) from the same thread. [...] Note that store-load reorderings may also arise due to local bypassing in the commonly implemented FIFO write buffer, even with a core that executes all instructions in program order.

“写缓冲区中的本地旁路”是什么意思？写缓冲区是存储缓冲区的另一个名称吗？

谢谢

Answer 1

写缓冲区中的本地旁路可能意味着store-to-load forwarding:

Store-to-Load Forwarding

When a load depends on a recent earlier store, the data that should be loaded is not yet in the cache, and needs to be forwarded from the store, through the store queue. This can be done by searching the store queue (like a CAM) for a store whose address matches the load, then retrieving the data from the store queue rather than L1 cache if there is a match.