diff options
| author | Rasmus Villemoes <linux@rasmusvillemoes.dk> | 2015-02-13 14:36:10 -0800 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-04-11 10:59:36 +0200 |
| commit | d83e0f90a3a7087d5c8db28e990d807b31781c74 (patch) | |
| tree | 2989ad202d5143e51bc28473db9154cce61d312e /lib | |
| parent | 182df8d94f7b75d0274a774c704c077bc1fbbdf3 (diff) | |
lib: bitmap: yet another simplification in __bitmap_shift_right
If left is 0, we can just let mask be ~0UL, so that anding with it is a
no-op. Conveniently, BITMAP_LAST_WORD_MASK provides precisely what we
need, and we can eliminate left.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/bitmap.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/lib/bitmap.c b/lib/bitmap.c index e3e91a343..62cac563c 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -111,9 +111,9 @@ EXPORT_SYMBOL(__bitmap_complement); void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, unsigned shift, unsigned nbits) { - unsigned k, lim = BITS_TO_LONGS(nbits), left = nbits % BITS_PER_LONG; + unsigned k, lim = BITS_TO_LONGS(nbits); unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; - unsigned long mask = (1UL << left) - 1; + unsigned long mask = BITMAP_LAST_WORD_MASK(nbits); for (k = 0; off + k < lim; ++k) { unsigned long upper, lower; @@ -125,12 +125,12 @@ void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, upper = 0; else { upper = src[off + k + 1]; - if (off + k + 1 == lim - 1 && left) + if (off + k + 1 == lim - 1) upper &= mask; upper <<= (BITS_PER_LONG - rem); } lower = src[off + k]; - if (left && off + k == lim - 1) + if (off + k == lim - 1) lower &= mask; lower >>= rem; dst[k] = lower | upper; |