[PATCH 05/10] test-mergesort: use DEFINE_LIST_SORT

["René Scharfe" <l.s.r@web.de>]

Build a typed sort function for the mergesort performance test tool
using DEFINE_LIST_SORT instead of calling llist_mergesort().  This gets
rid of the next pointer accessor functions and improves the performance
at the cost of a slightly higher object text size.

Before:
0071.12: llist_mergesort() unsorted    0.24(0.22+0.01)
0071.14: llist_mergesort() sorted      0.12(0.10+0.01)
0071.16: llist_mergesort() reversed    0.12(0.10+0.01)

__TEXT	__DATA	__OBJC	others	dec	hex
6407	276	0	24701	31384	7a98	t/helper/test-mergesort.o

With this patch:
0071.12: DEFINE_LIST_SORT unsorted     0.22(0.21+0.01)
0071.14: DEFINE_LIST_SORT sorted       0.11(0.10+0.01)
0071.16: DEFINE_LIST_SORT reversed     0.11(0.10+0.01)

__TEXT	__DATA	__OBJC	others	dec	hex
6615	276	0	25832	32723	7fd3	t/helper/test-mergesort.o

Signed-off-by: René Scharfe <l.s.r@web.de>
---
 t/helper/test-mergesort.c | 15 +++------------
 t/perf/p0071-sort.sh      |  4 ++--
 2 files changed, 5 insertions(+), 14 deletions(-)

diff --git a/t/helper/test-mergesort.c b/t/helper/test-mergesort.c
index 93d15d59a1..202e54a7ff 100644
--- a/t/helper/test-mergesort.c
+++ b/t/helper/test-mergesort.c
@@ -13,19 +13,10 @@ struct line {
 	struct line *next;
 };

-static void *get_next(const void *a)
-{
-	return ((const struct line *)a)->next;
-}
-
-static void set_next(void *a, void *b)
-{
-	((struct line *)a)->next = b;
-}
+DEFINE_LIST_SORT(static, sort_lines, struct line, next);

-static int compare_strings(const void *a, const void *b)
+static int compare_strings(const struct line *x, const struct line *y)
 {
-	const struct line *x = a, *y = b;
 	return strcmp(x->text, y->text);
 }

@@ -47,7 +38,7 @@ static int sort_stdin(void)
 		p = line;
 	}

-	lines = llist_mergesort(lines, get_next, set_next, compare_strings);
+	sort_lines(&lines, compare_strings);

 	while (lines) {
 		puts(lines->text);
diff --git a/t/perf/p0071-sort.sh b/t/perf/p0071-sort.sh
index ed366e2e12..ae4ddac864 100755
--- a/t/perf/p0071-sort.sh
+++ b/t/perf/p0071-sort.sh
@@ -40,11 +40,11 @@ done

 for file in unsorted sorted reversed
 do
-	test_perf "llist_mergesort() $file" "
+	test_perf "DEFINE_LIST_SORT $file" "
 		test-tool mergesort sort <$file >actual
 	"

-	test_expect_success "llist_mergesort() $file sorts like sort(1)" "
+	test_expect_success "DEFINE_LIST_SORT $file sorts like sort(1)" "
 		test_cmp_bin sorted actual
 	"
 done
--
2.37.1