MFC 278474,278476,280279:

Expand the bitcount*() API and use it to implement CPU_COUNT for cpusets.

278474:
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.

278476:
Use __builtin_popcountl() instead of __builtin_popcount().

280279:
Expand the bitcount* API to support 64-bit integers, plain ints and longs
and create a "hidden" API that can be used in other system headers without
adding namespace pollution.
- If the POPCNT instruction is enabled at compile time, use
  __builtin_popcount*() to implement __bitcount*(), otherwise fall back
  to software implementations.
- Use the existing bitcount16() and bitcount32() from <sys/systm.h> to
  implement the non-POPCNT __bitcount16() and __bitcount32() in
  <sys/types.h>.
- For the non-POPCNT __bitcount64(), use a similar SWAR method on 64-bit
  systems.  For 32-bit systems, use two __bitcount32() operations on the
  two halves.
- Use __bitcount32() to provide a __bitcount() that operates on plain ints.
- Use either __bitcount32() or __bitcount64() to provide a
  __bitcountl() that operates on longs.
- Add public bitcount*() wrappers for __bitcount*() for use in the kernel
  in <sys/libkern.h>.
- Use __bitcountl() instead of __builtin_popcountl() in BIT_COUNT().

1 files changed, 1 insertions, 0 deletions

diff --git a/sys/sys/cpuset.h b/sys/sys/cpuset.h
index f3ec3da..dfa2d31 100644
--- a/sys/sys/cpuset.h
+++ b/sys/sys/cpuset.h
@@ -60,6 +60,7 @@
 #define	CPU_OR_ATOMIC(d, s)		BIT_OR_ATOMIC(CPU_SETSIZE, d, s)
 #define	CPU_COPY_STORE_REL(f, t)	BIT_COPY_STORE_REL(CPU_SETSIZE, f, t)
 #define	CPU_FFS(p)			BIT_FFS(CPU_SETSIZE, p)
+#define	CPU_COUNT(p)			BIT_COUNT(CPU_SETSIZE, p)
 
 /*
  * Valid cpulevel_t values.