diff options
| author | Rasmus Villemoes <linux@rasmusvillemoes.dk> | 2015-02-13 14:36:19 -0800 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-04-11 10:59:37 +0200 |
| commit | 9f94f0a11d476b3a9c02e3d78681de9a0d763ea4 (patch) | |
| tree | 973d93ea68ba3d0bc1caf0316d4257bdd62ba6a9 /lib/bitmap.c | |
| parent | 2dc5a5a532a5992c47892b1f84ffbcfa4ff36786 (diff) | |
lib: bitmap: remove redundant code from __bitmap_shift_left
The first of these conditionals is completely redundant: If k == lim-1, we
must have off==0, so the second conditional will also trigger and then it
wouldn't matter if upper had some high bits set. But the second
conditional is in fact also redundant, since it only serves to clear out
some high-order "don't care" bits of dst, about which no guarantee is
made.
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/bitmap.c')
| -rw-r--r-- | lib/bitmap.c | 9 |
1 files changed, 2 insertions, 7 deletions
diff --git a/lib/bitmap.c b/lib/bitmap.c index ef4a8a992..8da1380eb 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -157,7 +157,7 @@ void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, unsigned int shift, unsigned int nbits) { int k; - unsigned int lim = BITS_TO_LONGS(nbits), left = nbits % BITS_PER_LONG; + unsigned int lim = BITS_TO_LONGS(nbits); unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; for (k = lim - off - 1; k >= 0; --k) { unsigned long upper, lower; @@ -170,13 +170,8 @@ void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, lower = src[k - 1] >> (BITS_PER_LONG - rem); else lower = 0; - upper = src[k]; - if (left && k == lim - 1) - upper &= (1UL << left) - 1; - upper <<= rem; + upper = src[k] << rem; dst[k + off] = lower | upper; - if (left && k + off == lim - 1) - dst[k + off] &= (1UL << left) - 1; } if (off) memset(dst, 0, off*sizeof(unsigned long)); |