> > Sounds good to me. Although, users building with just -msse4.2 will > > now encounter an an additional pclmul runtime check. That would be a > > regression unless they update to building with both -msse4.2 and -mpclmul. > > My thinking was that building with just -msse4.2 would cause the existing SSE > 4.2 > implementation to be used (without the function pointer). That's admittedly > a bit > goofy because they'd miss out on the PCLMUL optimization, but things at least > don't get any worse for them.
Right. We are only talking about a regression for small potion of people who build with -msse4.2 and run on Nehalem/VM with pclmul disabled where we will run the cpuid check for pclmul and still pick the sse4.2 version. Raghuveer
