From: Taylor Blau <me@ttaylorr.com>
Date: Thu, 23 May 2024 21:27:02 +0000 (-0400)
Subject: ewah: implement `ewah_bitmap_popcount()`
X-Git-Tag: v2.46.0-rc0~36^2~9
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0481cbf912e23d96076e3a7e149e76a0327a7a70;p=thirdparty%2Fgit.git

ewah: implement `ewah_bitmap_popcount()`

Some of the pseudo-merge test helpers (which will be introduced in the
following commit) will want to indicate the total number of commits in
or objects reachable from a pseudo-merge.

Implement a popcount() function that operates on EWAH bitmaps to quickly
determine how many bits are set in each of the respective bitmaps.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

diff --git a/ewah/bitmap.c b/ewah/bitmap.c
index d352fec54c..dc2ca190f1 100644
--- a/ewah/bitmap.c
+++ b/ewah/bitmap.c
@@ -212,6 +212,20 @@ size_t bitmap_popcount(struct bitmap *self)
 	return count;
 }
 
+size_t ewah_bitmap_popcount(struct ewah_bitmap *self)
+{
+	struct ewah_iterator it;
+	eword_t word;
+	size_t count = 0;
+
+	ewah_iterator_init(&it, self);
+
+	while (ewah_iterator_next(&word, &it))
+		count += ewah_bit_popcount64(word);
+
+	return count;
+}
+
 int bitmap_is_empty(struct bitmap *self)
 {
 	size_t i;
diff --git a/ewah/ewok.h b/ewah/ewok.h
index 2b6c4ac499..7074a6347b 100644
--- a/ewah/ewok.h
+++ b/ewah/ewok.h
@@ -195,6 +195,7 @@ void bitmap_or_ewah(struct bitmap *self, struct ewah_bitmap *other);
 void bitmap_or(struct bitmap *self, const struct bitmap *other);
 
 size_t bitmap_popcount(struct bitmap *self);
+size_t ewah_bitmap_popcount(struct ewah_bitmap *self);
 int bitmap_is_empty(struct bitmap *self);
 
 #endif