Create the function ebitmap_highest_set_bit() which returns the position
of the highest bit set in the ebitmap.
The return value is valid only if the ebitmap is not empty. An empty
ebitmap will return 0.
Signed-off-by: James Carter <jwcart2@gmail.com>
This reverts commit 542e878690.
After 6968ea9775 ("libsepol: make ebitmap_cardinality() of linear
complexity"), the caching only saves ~0.06 % of total semodule -BN
running time (on x86_64 without using the POPCNT instruction), so it's
no longer worth the added complexity.
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Create the macro ebitmap_is_empty() to check if an ebitmap is empty.
Use ebitmap_is_empty(), instead of ebitmap_cardinality() or
ebitmap_length(), to check whether or not an ebitmap is empty.
Signed-off-by: James Carter <jwcart2@gmail.com>
Acked-by: Ondrej Mosnacek <omosnace@redhat.com>
According to profiling of semodule -BN, ebitmap_cardinality() is called
quite often and contributes a lot to the total runtime. Cache its result
in the ebitmap struct to reduce this overhead. The cached value is
invalidated on most modifying operations, but ebitmap_cardinality() is
usually called once the ebitmap doesn't change any more.
After this patch, the time to do 'semodule -BN' on Fedora Rawhide has
decreased from ~10.9s to ~8.9s (2s saved).
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
[sds@tycho.nsa.gov: correct times per follow-up on list]
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Most of the users of ebitmap_for_each_bit() macro only care for the set
bits, so introduce a new ebitmap_for_each_positive_bit() macro that
skips the unset bits. Replace uses of ebitmap_for_each_bit() with the
new macro where appropriate.
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
This patches moves some ebitmap functions (and, xor, not, etc.) from
mcstrans into libsepol, where they really belong and could be used by
other applications (e.g. CIL)
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Dan Walsh <dwalsh@redhat.com>
