[PATCH 10/18] lib: bitmap: Make the start index of bitmap_set unsigned

From: Rasmus Villemoes
Date: Thu Jul 03 2014 - 18:46:25 EST


The compiler can generate slightly smaller and simpler code when it
knows that "start" is non-negative.

Also, use the names "start" and "len" for the two parameters in both
header file and implementation, instead of the previous mix.

Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
---
include/linux/bitmap.h | 2 +-
lib/bitmap.c | 10 +++++-----
2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 64b0ebe..ad2c67d 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -112,7 +112,7 @@ extern int __bitmap_subset(const unsigned long *bitmap1,
const unsigned long *bitmap2, unsigned int nbits);
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_set(unsigned long *map, unsigned int start, int len);
extern void bitmap_clear(unsigned long *map, int start, int nr);
extern unsigned long bitmap_find_next_zero_area(unsigned long *map,
unsigned long size,
diff --git a/lib/bitmap.c b/lib/bitmap.c
index f69435c..2a3a92f 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -274,21 +274,21 @@ int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
}
EXPORT_SYMBOL(__bitmap_weight);

-void bitmap_set(unsigned long *map, int start, int nr)
+void bitmap_set(unsigned long *map, unsigned int start, int len)
{
unsigned long *p = map + BIT_WORD(start);
- const int size = start + nr;
+ const unsigned int size = start + len;
int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);

- while (nr - bits_to_set >= 0) {
+ while (len - bits_to_set >= 0) {
*p |= mask_to_set;
- nr -= bits_to_set;
+ len -= bits_to_set;
bits_to_set = BITS_PER_LONG;
mask_to_set = ~0UL;
p++;
}
- if (nr) {
+ if (len) {
mask_to_set &= BITMAP_LAST_WORD_MASK(size);
*p |= mask_to_set;
}
--
1.9.2

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