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authorRasmus Villemoes <linux@rasmusvillemoes.dk>2015-02-13 14:36:19 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-02-13 21:21:35 -0800
commit7f590657937f1c59163ff14a13062439a18e4a37 (patch)
treec07798a14a2394d7fc7771e1baa95b90e63539bc
parent6d874eca6595629258a5d9af237c5ae53a9544e1 (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>
-rw-r--r--lib/bitmap.c9
1 files changed, 2 insertions, 7 deletions
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 36e380da00c5..a13c7f4e325a 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -159,7 +159,7 @@ 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;
@@ -172,13 +172,8 @@ 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));