From 877d9f3b63ac2e5dbc51cbcdff156433f03b3a32 Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Wed, 6 Aug 2014 16:10:05 -0700 Subject: [PATCH] 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/bitmap.h | 4 ++-- lib/bitmap.c | 5 +++-- 2 files changed, 5 insertions(+), 4 deletions(-) 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 @@ extern int __bitmap_intersects(const unsigned long *bitmap1, 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 @@ static inline int bitmap_full(const unsigned long *src, unsigned int nbits) 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 @@ int __bitmap_subset(const unsigned long *bitmap1, } 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]); -- 2.7.4