linux-kernel - [PATCH] lib: bitmap_[empty,full]: remove code duplication

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Date:	Mon, 16 Mar 2015 20:56:39 +0300
From:	Yury Norov <yury.norov@...il.com>
To:	linux@...izon.com, klimov.linux@...il.com,
	linux@...musvillemoes.dk, akpm@...ux-foundation.org
Cc:	yury.norov@...il.com, linux-kernel@...r.kernel.org
Subject: [PATCH] lib: bitmap_[empty,full]: remove code duplication

Function 'bitmap_empty' has it's own implementation.
But it's clearly as simple as:
	"find_first_bit(src, nbits) == nbits"
The same is true for 'bitmap_full'.

Underscored versions of 'bitmap_[empty,full]' are not
needed anymore and so removed too.

Boot-tested on Core i7-2630QM.

---
 include/linux/bitmap.h | 10 ++--------
 lib/bitmap.c           | 30 ------------------------------
 2 files changed, 2 insertions(+), 38 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index dbfbf49..a56e250 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -285,18 +285,12 @@ static inline int bitmap_subset(const unsigned long *src1,
 
 static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
 {
-	if (small_const_nbits(nbits))
-		return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
-	else
-		return __bitmap_empty(src, nbits);
+	return find_first_bit(src, nbits) == nbits;
 }
 
 static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
 {
-	if (small_const_nbits(nbits))
-		return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
-	else
-		return __bitmap_full(src, nbits);
+	return find_first_zero_bit(src, nbits) == nbits;
 }
 
 static inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
diff --git a/lib/bitmap.c b/lib/bitmap.c
index d456f4c1..64c0926 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -42,36 +42,6 @@
  * for the best explanations of this ordering.
  */
 
-int __bitmap_empty(const unsigned long *bitmap, unsigned int bits)
-{
-	unsigned int k, lim = bits/BITS_PER_LONG;
-	for (k = 0; k < lim; ++k)
-		if (bitmap[k])
-			return 0;
-
-	if (bits % BITS_PER_LONG)
-		if (bitmap[k] & BITMAP_LAST_WORD_MASK(bits))
-			return 0;
-
-	return 1;
-}
-EXPORT_SYMBOL(__bitmap_empty);
-
-int __bitmap_full(const unsigned long *bitmap, unsigned int bits)
-{
-	unsigned int k, lim = bits/BITS_PER_LONG;
-	for (k = 0; k < lim; ++k)
-		if (~bitmap[k])
-			return 0;
-
-	if (bits % BITS_PER_LONG)
-		if (~bitmap[k] & BITMAP_LAST_WORD_MASK(bits))
-			return 0;
-
-	return 1;
-}
-EXPORT_SYMBOL(__bitmap_full);
-
 int __bitmap_equal(const unsigned long *bitmap1,
 		const unsigned long *bitmap2, unsigned int bits)
 {
-- 
2.1.0

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