svn commit: r278474 - head/sys/sys

[Jung-uk Kim]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

On 02/09/2015 16:08, John Baldwin wrote:
> On Monday, February 09, 2015 09:03:24 PM John Baldwin wrote:
>> Author: jhb Date: Mon Feb  9 21:03:23 2015 New Revision: 278474 
>> URL: https://svnweb.freebsd.org/changeset/base/278474
>> 
>> Log: Use __builtin_popcnt() to implement a BIT_COUNT() operation 
>> for bitsets and use this to implement CPU_COUNT() to count the 
>> number of CPUs in a cpuset.
>> 
>> MFC after:	2 weeks
> 
> Yes, __builtin_popcnt() works with GCC 4.2.  It should also allow 
> the compiler to DTRT in userland uses of this if -msse4.2 is 
> enabled.

Back in 2012, when I submitted a similar patch, bde noted
__builtin_popcount*() cannot be used with GCC 4.2 for *kernel* because
it emits a library call.

http://docs.freebsd.org/cgi/mid.cgi?20121116171923.L1135

FYI...

Jung-uk Kim
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2

iQEcBAEBCAAGBQJU2SzhAAoJEHyflib82/FGzgoH/2mfCZTX6J84MYpfuJV5dnLQ
97Itozifc8qBNDCOIQ1PZNgxPed9U8Ma0o3Rntfl5X2VeAIc/c5JJhvQITUdhnn7
fyW5FcpvJGpHLcUWlTMT5CrZgmDswi6h1jIsbD6AKoIVNGau5kPhpn4LF7f19YU0
0Vm8L96gGrxjJb3SWdRC4znP1ezTCw3rUEyk2oPZBn69zoat1vBcV7WtathStcBg
noIEydo6C5e4EC5SKbTi29aNd1KGafRIukkC8+jnZNCc8nYEVsUEX5SarKYmmpec
NTSLfboTJ5YXZGsvIgGzld0Z/Hn54v8O0hhG1QO4kWh3wN40NVgNL0vkeiveqwE=
=WDqA
-----END PGP SIGNATURE-----