Not using the intrinsic shouldn't make any difference here. But __popcnt is the intrinsic, not the instruction. Shouldn't MS compiler automatically detect hardware support and use another solution if the popcnt isn't available.
On Wed, Apr 25, 2012 at 9:22 AM, Florian Schneider <[email protected]>wrote: > Hm, interesting. I assume that we don't instruct g++ or msvc to generate > any fancy SSE4.1 instructions anyway because V8 has to run on old non-SSE > hardware - in which case the benefit of using the compiler intrinsics is > probably void. > > Den 24. apr. 2012 19.20 skrev Vitaly Repeshko <[email protected]>: > > FYI. http://msdn.microsoft.com/en-us/library/bb385231.aspx says "If >> you run code that uses this intrinsic on hardware that does not >> support the popcnt instruction, the results are unpredictable." >> >> >> -- Vitaly >> >> On Tue, Apr 24, 2012 at 10:03 AM, Florian Schneider >> <[email protected]> wrote: >> > You're welcome. The Win32 builder still not happy. I'm not so familiar >> with >> > our Windows buildbot configuration, so I'm fixing it for now by just >> > avoiding the problematic compiler intrinsic >> > (http://code.google.com/p/v8/source/detail?r=11428) It should not make >> a big >> > difference, should it? >> > >> > >> > >> > Den 24. apr. 2012 18.14 skrev Alexandre Rames < >> [email protected]>: >> > >> >> Thanks! >> >> >> >> >> >> On Tue, Apr 24, 2012 at 4:36 PM, <[email protected]> wrote: >> >>> >> >>> Thanks. Still LGTM. >> >>> >> >>> I'll re-land it >> >>> >> >>> http://codereview.chromium.org/9638018/ >> >> >> >> >> > >> > -- >> > v8-dev mailing list >> > [email protected] >> > http://groups.google.com/group/v8-dev >> >> -- >> v8-dev mailing list >> [email protected] >> http://groups.google.com/group/v8-dev >> > > -- v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev
