On Fri, 6 Mar 2020 at 10:23, linmiaohe <linmiaohe@xxxxxxxxxx> wrote: > > hpa@xxxxxxxxx wrote: > >>On March 5, 2020 6:05:40 PM PST, linmiaohe <linmiaohe@xxxxxxxxxx> wrote: > >>Hi, > >>Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote: > >>Many thanks for suggestion. What do you mean is like this ? > >> > >> index = (msr - 0x200) >> 1; > >> is_mtrr_mask = msr & 1; > >> > >>Thanks again. > > > >You realize that the compiler will probably produce exactly the same code, right? As such, it is about making the code easy for the human reader. > > > >Even if it didn't, this code is as far from performance critical as one can possibly get. > > Yep, it looks gain little. Thanks. Please post the performance number when you mention optimize XXX later. Wanpeng