[PATCH v2 06/24] ewah: factor out bitmap growth
- From
Taylor Blau <me@ttaylorr.com>
- Date
- Nov 17, 2020, 21:46 UTC
- Message-ID
- <9bb1ea3b19c86507b7485ae872a8ef350cd0aedc.1605649533.git.me@ttaylorr.com>
- In-Reply-To
- <cover.1605649533.git.me@ttaylorr.com>
From: Jeff King <peff@peff.net>
We auto-grow bitmaps when somebody asks to set a bit whose position is outside of our currently allocated range. Other operations besides single bit-setting might need to do this, too, so let's pull it into its own function.
Note that we change the semantics a little: you now ask for the number of words you'd like to have, not the id of the block you'd like to write to.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> --- ewah/bitmap.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/ewah/bitmap.c b/ewah/bitmap.c index d8cec585af..7c1ecfa6fd 100644 --- a/ewah/bitmap.c +++ b/ewah/bitmap.c @@ -35,18 +35,22 @@ struct bitmap *bitmap_new(void) return bitmap_word_alloc(32); } -void bitmap_set(struct bitmap *self, size_t pos) +static void bitmap_grow(struct bitmap *self, size_t word_alloc) { - size_t block = EWAH_BLOCK(pos); - - if (block >= self->word_alloc) { + if (word_alloc > self->word_alloc) { size_t old_size = self->word_alloc; - self->word_alloc = block ? block * 2 : 1; + self->word_alloc = word_alloc * 2; REALLOC_ARRAY(self->words, self->word_alloc); memset(self->words + old_size, 0x0, (self->word_alloc - old_size) * sizeof(eword_t)); } +} +void bitmap_set(struct bitmap *self, size_t pos) +{ + size_t block = EWAH_BLOCK(pos); + + bitmap_grow(self, block + 1); self->words[block] |= EWAH_MASK(pos); }
-- 2.29.2.312.gabc4d358d8