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Commit 9d8a6b2a authored by Rasmus Villemoes's avatar Rasmus Villemoes Committed by Linus Torvalds
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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: default avatarRasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 2fbad299

lib/bitmap.c

+3 −3
Original line number Original line Diff line number Diff line
@@ -129,13 +129,13 @@ void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, 
			upper = src[off + k + 1];

			upper = src[off + k + 1];

			if (off + k + 1 == lim - 1 && left)

			if (off + k + 1 == lim - 1 && left)

				upper &= mask;

				upper &= mask;

			upper <<= (BITS_PER_LONG - rem);

		}

		}

		lower = src[off + k];

		lower = src[off + k];

		if (left && off + k == lim - 1)

		if (left && off + k == lim - 1)

			lower &= mask;

			lower &= mask;

		dst[k] = lower >> rem;

		lower >>= rem;

		if (rem)

		dst[k] = lower | upper;

			dst[k] |= upper << (BITS_PER_LONG - rem);

		if (left && k == lim - 1)

		if (left && k == lim - 1)

			dst[k] &= mask;

			dst[k] &= mask;

	}

	}