use DIV_ROUND_UP

Convert code that divides and rounds up to use DIV_ROUND_UP to make the
intent clearer and reduce the number of magic constants.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/gc.c

@@ -148,7 +148,7 @@ static int too_many_loose_objects(void)
 	if (!dir)
 		return 0;
 
-	auto_threshold = (gc_auto_threshold + 255) / 256;
+	auto_threshold = DIV_ROUND_UP(gc_auto_threshold, 256);
 	while ((ent = readdir(dir)) != NULL) {
 		if (strspn(ent->d_name, "0123456789abcdef") != 38 ||
 		    ent->d_name[38] != '\0')

builtin/grep.c

@@ -524,7 +524,7 @@ static void compile_submodule_options(const struct grep_opt *opt,
 	 * submodule process has its own thread pool.
 	 */
 	argv_array_pushf(&submodule_options, "--threads=%d",
-			 (num_threads + 1) / 2);
+			 DIV_ROUND_UP(num_threads, 2));
 
 	/* Add Pathspecs */
 	argv_array_push(&submodule_options, "--");

builtin/log.c

@@ -1302,7 +1302,7 @@ static struct commit *get_base_commit(const char *base_commit,
 
 		if (rev_nr % 2)
 			rev[i] = rev[2 * i];
-		rev_nr = (rev_nr + 1) / 2;
+		rev_nr = DIV_ROUND_UP(rev_nr, 2);
 	}
 
 	if (!in_merge_bases(base, rev[0]))

builtin/receive-pack.c

@@ -1805,7 +1805,7 @@ static const char *unpack_with_sideband(struct shallow_info *si)
 static void prepare_shallow_update(struct command *commands,
 				   struct shallow_info *si)
 {
-	int i, j, k, bitmap_size = (si->ref->nr + 31) / 32;
+	int i, j, k, bitmap_size = DIV_ROUND_UP(si->ref->nr, 32);
 
 	ALLOC_ARRAY(si->used_shallow, si->shallow->nr);
 	assign_shallow_commits_to_refs(si, si->used_shallow, NULL);

diff.c

@@ -2095,7 +2095,7 @@ static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *o
 			 * bytes per "line".
 			 * This is stupid and ugly, but very cheap...
 			 */
-			damage = (damage + 63) / 64;
+			damage = DIV_ROUND_UP(damage, 64);
 		ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
 		dir.files[dir.nr].name = file->name;
 		dir.files[dir.nr].changed = damage;

ewah/ewah_bitmap.c

@@ -210,8 +210,8 @@ size_t ewah_add(struct ewah_bitmap *self, eword_t word)
 void ewah_set(struct ewah_bitmap *self, size_t i)
 {
 	const size_t dist =
-		(i + BITS_IN_EWORD) / BITS_IN_EWORD -
-		(self->bit_size + BITS_IN_EWORD - 1) / BITS_IN_EWORD;
+		DIV_ROUND_UP(i + 1, BITS_IN_EWORD) -
+		DIV_ROUND_UP(self->bit_size, BITS_IN_EWORD);
 
 	assert(i >= self->bit_size);
 

imap-send.c

@@ -861,7 +861,7 @@ static char hexchar(unsigned int b)
 	return b < 10 ? '0' + b : 'a' + (b - 10);
 }
 
-#define ENCODED_SIZE(n) (4*((n+2)/3))
+#define ENCODED_SIZE(n) (4 * DIV_ROUND_UP((n), 3))
 static char *cram(const char *challenge_64, const char *user, const char *pass)
 {
 	int i, resp_len, encoded_len, decoded_len;

sha1_name.c

@@ -479,10 +479,9 @@ int find_unique_abbrev_r(char *hex, const unsigned char *sha1, int len)
 		 * We now know we have on the order of 2^len objects, which
 		 * expects a collision at 2^(len/2). But we also care about hex
 		 * chars, not bits, and there are 4 bits per hex. So all
-		 * together we need to divide by 2; but we also want to round
-		 * odd numbers up, hence adding one before dividing.
+		 * together we need to divide by 2 and round up.
 		 */
-		len = (len + 1) / 2;
+		len = DIV_ROUND_UP(len, 2);
 		/*
 		 * For very small repos, we stick with our regular fallback.
 		 */

shallow.c

@@ -443,7 +443,7 @@ struct paint_info {
 
 static uint32_t *paint_alloc(struct paint_info *info)
 {
-	unsigned nr = (info->nr_bits + 31) / 32;
+	unsigned nr = DIV_ROUND_UP(info->nr_bits, 32);
 	unsigned size = nr * sizeof(uint32_t);
 	void *p;
 	if (!info->pool_count || size > info->end - info->free) {
@@ -471,7 +471,7 @@ static void paint_down(struct paint_info *info, const unsigned char *sha1,
 {
 	unsigned int i, nr;
 	struct commit_list *head = NULL;
-	int bitmap_nr = (info->nr_bits + 31) / 32;
+	int bitmap_nr = DIV_ROUND_UP(info->nr_bits, 32);
 	size_t bitmap_size = st_mult(sizeof(uint32_t), bitmap_nr);
 	struct commit *c = lookup_commit_reference_gently(sha1, 1);
 	uint32_t *tmp; /* to be freed before return */
@@ -611,7 +611,7 @@ void assign_shallow_commits_to_refs(struct shallow_info *info,
 		paint_down(&pi, ref->oid[i].hash, i);
 
 	if (used) {
-		int bitmap_size = ((pi.nr_bits + 31) / 32) * sizeof(uint32_t);
+		int bitmap_size = DIV_ROUND_UP(pi.nr_bits, 32) * sizeof(uint32_t);
 		memset(used, 0, sizeof(*used) * info->shallow->nr);
 		for (i = 0; i < nr_shallow; i++) {
 			const struct commit *c = lookup_commit(oid[shallow[i]].hash);
@@ -672,7 +672,7 @@ static void post_assign_shallow(struct shallow_info *info,
 	struct commit *c;
 	uint32_t **bitmap;
 	int dst, i, j;
-	int bitmap_nr = (info->ref->nr + 31) / 32;
+	int bitmap_nr = DIV_ROUND_UP(info->ref->nr, 32);
 	struct commit_array ca;
 
 	trace_printf_key(&trace_shallow, "shallow: post_assign_shallow\n");