[Qemu-devel] [PATCH v3 1/2] bitmap: get last word mask from nr directly

[Wei Yang]

The value left in nr is the number of bits for the last word, which
could be calculate the last word mask directly.

Remove the unnecessary size.

Signed-off-by: Wei Yang <address@hidden>

---
v2: refine bitmap_set_atomic too, suggested from Peter
---
 util/bitmap.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/util/bitmap.c b/util/bitmap.c
index 1753ff7f5b..5b15249796 100644
--- a/util/bitmap.c
+++ b/util/bitmap.c
@@ -160,7 +160,6 @@ int slow_bitmap_andnot(unsigned long *dst, const unsigned 
long *bitmap1,
 void bitmap_set(unsigned long *map, long start, long nr)
 {
     unsigned long *p = map + BIT_WORD(start);
-    const long size = start + nr;
     int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
     unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
 
@@ -174,7 +173,7 @@ void bitmap_set(unsigned long *map, long start, long nr)
         p++;
     }
     if (nr) {
-        mask_to_set &= BITMAP_LAST_WORD_MASK(size);
+        mask_to_set &= BITMAP_LAST_WORD_MASK(nr);
         *p |= mask_to_set;
     }
 }
@@ -182,7 +181,6 @@ void bitmap_set(unsigned long *map, long start, long nr)
 void bitmap_set_atomic(unsigned long *map, long start, long nr)
 {
     unsigned long *p = map + BIT_WORD(start);
-    const long size = start + nr;
     int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
     unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
 
@@ -208,7 +206,7 @@ void bitmap_set_atomic(unsigned long *map, long start, long 
nr)
 
     /* Last word */
     if (nr) {
-        mask_to_set &= BITMAP_LAST_WORD_MASK(size);
+        mask_to_set &= BITMAP_LAST_WORD_MASK(nr);
         atomic_or(p, mask_to_set);
     } else {
         /* If we avoided the full barrier in atomic_or(), issue a
@@ -221,7 +219,6 @@ void bitmap_set_atomic(unsigned long *map, long start, long 
nr)
 void bitmap_clear(unsigned long *map, long start, long nr)
 {
     unsigned long *p = map + BIT_WORD(start);
-    const long size = start + nr;
     int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
     unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
 
@@ -235,7 +232,7 @@ void bitmap_clear(unsigned long *map, long start, long nr)
         p++;
     }
     if (nr) {
-        mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
+        mask_to_clear &= BITMAP_LAST_WORD_MASK(nr);
         *p &= ~mask_to_clear;
     }
 }
-- 
2.17.1