lib: bitmap: remove redundant code from __bitmap_shift_right

If the condition k==lim-1 is true, we must have off == 0 (otherwise, k
could never become that big).  But in that case we have upper == 0 and
hence dst[k] == (src[k] & mask) >> rem.  Since mask consists of a
consecutive range of bits starting from the LSB, anding dst[k] with mask
is a no-op.

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>

diff --git a/lib/bitmap.c b/lib/bitmap.c
index a7a8bc02892dbfbb1d3b7b1942cb3c9b030b9f6c..761d2d4989eee2268eb92f5c36cb5da282335e51 100644 (file)
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -136,8 +136,6 @@ void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
                        lower &= mask;
                lower >>= rem;
                dst[k] = lower | upper;
-               if (left && k == lim - 1)
-                       dst[k] &= mask;
        }
        if (off)
                memset(&dst[lim - off], 0, off*sizeof(unsigned long));