On Fri, 2021-03-26 at 07:11 -0600, Richard Henderson wrote: > On 3/25/21 7:47 PM, Robert Hoo wrote: > > On Thu, 2021-03-25 at 06:39 -0600, Richard Henderson wrote: > > > On 3/24/21 9:15 PM, Robert Hoo wrote: > > > > > > + } else if (env->xcr0 & XFEATURE_AVX) { > > > > > > > > > > This is normally a 2-bit test. > > > > > > > > I beg your pardon. What 2 bits? > > > > > > I forget the names, but isn't the usual test xcr0 & 6 == 6? > > > > 6 stands for SSE state-component and AVX state-component. > > I'm not sure about this. > > Can you remember where did you this "xcr0 & 6 == 6"? I can look > > into > > that. > > IA-64 and IA32 Software developers manual, Vol 1 Basic Architecture, > Section > 14.3 Detection of AVX instructions.
OK, thanks Richard. If use the feature detection criteria here, then AVX512 case will also need XCR0[2:1]='11b'. I'm going to send v4 soon. > > > r~