bitmap: introduce bitmap_weighted_xor()

The function helps to XOR bitmaps and calculate Hamming weight of
the result in one pass.

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Yury Norov <ynorov@nvidia.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/lib/bitmap.c b/lib/bitmap.c
index 1b897f94e0ff..b9bfa157e095 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -363,6 +363,13 @@ unsigned int __bitmap_weighted_or(unsigned long *dst, const unsigned long *bitma
 }
 EXPORT_SYMBOL(__bitmap_weighted_or);
 
+unsigned int __bitmap_weighted_xor(unsigned long *dst, const unsigned long *bitmap1,
+				  const unsigned long *bitmap2, unsigned int bits)
+{
+	return BITMAP_WEIGHT(({dst[idx] = bitmap1[idx] ^ bitmap2[idx]; dst[idx]; }), bits);
+}
+EXPORT_SYMBOL(__bitmap_weighted_xor);
+
 void __bitmap_set(unsigned long *map, unsigned int start, int len)
 {
 	unsigned long *p = map + BIT_WORD(start);