RISCv 非特权指令集规范，介绍IFMAD标准扩展，32位及64位，2019.6.8日更新。Preface
This document describes the risc-v unprivileged architecture
The rvWMO memory model has been ratified at this time. The ISa modules marked Ratified, have
bccn ratified at this timc. Thc modules m
