lib: bitmap: eliminate branch in __bitmap_shift_right
We can shift the bits from lower and upper into place before assembling
dst[k]; moving the shift of upper into the branch where we already know
that rem is non-zero allows us to remove a conditional.
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 45e7d14..a7a8bc0 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -129,13 +129,13 @@
upper = src[off + k + 1];
if (off + k + 1 == lim - 1 && left)
upper &= mask;
+ upper <<= (BITS_PER_LONG - rem);
}
lower = src[off + k];
if (left && off + k == lim - 1)
lower &= mask;
- dst[k] = lower >> rem;
- if (rem)
- dst[k] |= upper << (BITS_PER_LONG - rem);
+ lower >>= rem;
+ dst[k] = lower | upper;
if (left && k == lim - 1)
dst[k] &= mask;
}