ROB(re-order buffer, 重排序缓冲区)允许处理器指令乱序执行, 之后按照原有顺序提交. 目前 普遍使用Tomasulo算法.
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https://pcisig.com/sites/default/files/specification_documents/ECN_Internal-Error-Reporting_24Apr08.pdf
https://www.intel.com/content/dam/www/public/us/en/documents/white-papers/rob-timeout-debug-guide-paper.pdf