pass constants as first argument to st_mult()

The result of st_mult() is the same no matter the order of its
arguments.  It invokes the macro unsigned_mult_overflows(), which
divides the second parameter by the first one.  Pass constants
first to allow that division to be done already at compile time.

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>

diffcore-rename.c

@@ -541,7 +541,7 @@ void diffcore_rename(struct diff_options *options)
 				rename_dst_nr * rename_src_nr, 50, 1);
 	}
 
-	mx = xcalloc(st_mult(num_create, NUM_CANDIDATE_PER_DST), sizeof(*mx));
+	mx = xcalloc(st_mult(NUM_CANDIDATE_PER_DST, num_create), sizeof(*mx));
 	for (dst_cnt = i = 0; i < rename_dst_nr; i++) {
 		struct diff_filespec *two = rename_dst[i].two;
 		struct diff_score *m;

refs.c

@@ -922,7 +922,7 @@ char *shorten_unambiguous_ref(const char *refname, int strict)
 			/* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
 			total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
 
-		scanf_fmts = xmalloc(st_add(st_mult(nr_rules, sizeof(char *)), total_len));
+		scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
 
 		offset = 0;
 		for (i = 0; i < nr_rules; i++) {

shallow.c

@@ -389,7 +389,7 @@ 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;
-	size_t bitmap_size = st_mult(bitmap_nr, sizeof(uint32_t));
+	size_t bitmap_size = st_mult(sizeof(uint32_t), bitmap_nr);
 	uint32_t *tmp = xmalloc(bitmap_size); /* to be freed before return */
 	uint32_t *bitmap = paint_alloc(info);
 	struct commit *c = lookup_commit_reference_gently(sha1, 1);