We've never needed to unset an individual bit in a bitmap until now.
Typically they start with all bits unset and we bitmap_set() them, or we
are applying another bitmap as a mask. But the easiest way to apply an
object filter to a bitmap result will be to unset the individual bits.
Signed-off-by: Jeff King <peff@xxxxxxxx>
---
ewah/bitmap.c | 8 ++++++++
ewah/ewok.h | 1 +
2 files changed, 9 insertions(+)
diff --git a/ewah/bitmap.c b/ewah/bitmap.c
index 52f1178db4..1c31b3e249 100644
--- a/ewah/bitmap.c
+++ b/ewah/bitmap.c
@@ -45,6 +45,14 @@ void bitmap_set(struct bitmap *self, size_t pos)
self->words[block] |= EWAH_MASK(pos);
}
+void bitmap_unset(struct bitmap *self, size_t pos)
+{
+ size_t block = EWAH_BLOCK(pos);
+
+ if (block < self->word_alloc)
+ self->words[block] &= ~EWAH_MASK(pos);
+}
+
int bitmap_get(struct bitmap *self, size_t pos)
{
size_t block = EWAH_BLOCK(pos);
diff --git a/ewah/ewok.h b/ewah/ewok.h
index 84b2a29faa..59f4ef7c4f 100644
--- a/ewah/ewok.h
+++ b/ewah/ewok.h
@@ -173,6 +173,7 @@ struct bitmap {
struct bitmap *bitmap_new(void);
void bitmap_set(struct bitmap *self, size_t pos);
+void bitmap_unset(struct bitmap *self, size_t pos);
int bitmap_get(struct bitmap *self, size_t pos);
void bitmap_reset(struct bitmap *self);
void bitmap_free(struct bitmap *self);
--
2.25.0.796.gcc29325708
