[PATCH v6 09/20] tools lib: Introduce bitmap_intersects() operation

[Alexey Bayduraev]

Introduce bitmap_intersects() routine that tests whether
bitmaps bitmap1 and bitmap2 intersects. This routine will
be used during thread masks initialization.

Acked-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Alexey Bayduraev <alexey.v.bayduraev@xxxxxxxxxxxxxxx>
---
 tools/include/linux/bitmap.h | 11 +++++++++++
 tools/lib/bitmap.c           | 14 ++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h
index 330dbf7509cc..9d959bc24859 100644
--- a/tools/include/linux/bitmap.h
+++ b/tools/include/linux/bitmap.h
@@ -18,6 +18,8 @@ int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
 int __bitmap_equal(const unsigned long *bitmap1,
 		   const unsigned long *bitmap2, unsigned int bits);
 void bitmap_clear(unsigned long *map, unsigned int start, int len);
+int __bitmap_intersects(const unsigned long *bitmap1,
+			const unsigned long *bitmap2, unsigned int bits);
 
 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
@@ -170,4 +172,13 @@ static inline int bitmap_equal(const unsigned long *src1,
 	return __bitmap_equal(src1, src2, nbits);
 }
 
+static inline int bitmap_intersects(const unsigned long *src1,
+			const unsigned long *src2, unsigned int nbits)
+{
+	if (small_const_nbits(nbits))
+		return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
+	else
+		return __bitmap_intersects(src1, src2, nbits);
+}
+
 #endif /* _PERF_BITOPS_H */
diff --git a/tools/lib/bitmap.c b/tools/lib/bitmap.c
index f4e914712b6f..db466ef7be9d 100644
--- a/tools/lib/bitmap.c
+++ b/tools/lib/bitmap.c
@@ -86,3 +86,17 @@ int __bitmap_equal(const unsigned long *bitmap1,
 
 	return 1;
 }
+
+int __bitmap_intersects(const unsigned long *bitmap1,
+			const unsigned long *bitmap2, unsigned int bits)
+{
+	unsigned int k, lim = bits/BITS_PER_LONG;
+	for (k = 0; k < lim; ++k)
+		if (bitmap1[k] & bitmap2[k])
+			return 1;
+
+	if (bits % BITS_PER_LONG)
+		if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
+			return 1;
+	return 0;
+}
-- 
2.19.0