On Mon, Jan 11, 2021 at 07:06:22AM -1000, Richard Henderson wrote: > On 1/10/21 6:31 PM, Roman Bolshakov wrote: > >> Also, if we're going to put this some place common, forcing the caller to > >> do > >> the cpuid that feeds this, then we should probably make all of the startup > >> cpuid stuff common as well. > >> > > > > I proposed the version because all callers of xgetbv instruction already > > call cpuid before invoking inline xgetbv. > > > >> Note that we'd probably have to use constructor priorities to get that > >> right > >> for util/bufferiszero.c. > >> > > > > Please correct me if I read this wrong. What you're saying is we should > > initialize cpuid in constructors and then use cached cpuid ecx in > > xgetbv() (and drop one argument, respectively)? > > I would have xgetbv and all of the cpuid values cached at startup, and all > three places would read global variables. >
It makes sense, thanks for the clarification. Do you think it should be part of the change Hill is doing or it might be a follow-up cleanup patch? -Roman
