lib: bitmap: make nbits parameter of bitmap_weight unsigned
The compiler can generate slightly smaller and simpler code when it
knows that "nbits" is non-negative. Since no-one passes a negative
bit-count, this shouldn't affect the semantics.
I didn't change the return type, since that might change the semantics
of some expression containing a call to bitmap_weight(). Certainly an
int is capable of holding the result.
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/include/linux/bitmap.h b/include/linux/bitmap.h
index 87e88f7..64b0ebe 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -110,7 +110,7 @@
const unsigned long *bitmap2, unsigned int nbits);
extern int __bitmap_subset(const unsigned long *bitmap1,
const unsigned long *bitmap2, unsigned int nbits);
-extern int __bitmap_weight(const unsigned long *bitmap, int bits);
+extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
extern void bitmap_set(unsigned long *map, int i, int len);
extern void bitmap_clear(unsigned long *map, int start, int nr);
@@ -273,7 +273,7 @@
return __bitmap_full(src, nbits);
}
-static inline int bitmap_weight(const unsigned long *src, int nbits)
+static inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
{
if (small_const_nbits(nbits))
return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
diff --git a/lib/bitmap.c b/lib/bitmap.c
index c9bff53..f69435c 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -259,9 +259,10 @@
}
EXPORT_SYMBOL(__bitmap_subset);
-int __bitmap_weight(const unsigned long *bitmap, int bits)
+int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
{
- int k, w = 0, lim = bits/BITS_PER_LONG;
+ unsigned int k, lim = bits/BITS_PER_LONG;
+ int w = 0;
for (k = 0; k < lim; k++)
w += hweight_long(bitmap[k]);