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>

1 files changed, 4 insertions, 4 deletions

diff --git a/lib/bitmap.c b/lib/bitmap.c
index 761d2d4989ee..db88512c3451 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -113,9 +113,9 @@ 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;
 
@@ -127,12 +127,12 @@ 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;