1b82e02f4d
Add a bit_count function, which efficiently counts the number of bits set in a bitstring. sys/sys/bitstring.h tests/sys/sys/bitstring_test.c share/man/man3/bitstring.3 Add bit_alloc sys/kern/subr_unit.c Use bit_count instead of a naive counting loop in check_unrhdr, used when INVARIANTS are enabled. The userland test runs about 6x faster in a generic build, or 8.5x faster when built for Nehalem, which has the POPCNT instruction. sys/sys/param.h Bump __FreeBSD_version due to the addition of bit_alloc UPDATING Add a note about the ABI incompatibility of the bitstring(3) changes, as suggested by lidl. Suggested by: gibbs Reviewed by: gibbs, ngie MFC after: 9 days X-MFC-With: 299090, 300538 Relnotes: yes Sponsored by: Spectra Logic Corp Differential Revision: https://reviews.freebsd.org/D6255 |
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| geom | ||
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| mac | ||
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| netinet | ||
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| pjdfstest | ||
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| sys | ||
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| Makefile.depend | ||