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 <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
iegor · Feb 14, 2015 · 97fb8e9 · 97fb8e9
1 parent 9d8a6b2
commit 97fb8e9
Showing 1 changed file with 0 additions and 2 deletions.
diff --git 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));