FWIW, I wouldn't be surprised if you only have a couple threads using this at a time max since it looks an awful lot Apple's AMX/SME stuff. Those Apple execution units only have single engines shared about per cluster.
XSAVE lets you not bother saving register state that user space hasn't changed at the granularity of each large feature.
alt Hacker News
On x86, basically whatever XSAVE writes out.
FWIW, I wouldn't be surprised if you only have a couple threads using this at a time max since it looks an awful lot Apple's AMX/SME stuff. Those Apple execution units only have single engines shared about per cluster.
XSAVE lets you not bother saving register state that user space hasn't changed at the granularity of each large feature.