1 files changed, 52 insertions, 0 deletions
diff --git a/stdlib/tst-ulabs.c b/stdlib/tst-ulabs.c
new file mode 100644
index 0000000..3b5323e
--- /dev/null
+++ b/stdlib/tst-ulabs.c
@@ -0,0 +1,52 @@
+/* Basic tests for ulabs.
+   Copyright (C) 2025 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <limits.h>
+#include <stdlib.h>
+
+#include <support/check.h>
+
+#define LARGE_PRIME 49999
+
+static int do_test (void)
+{
+  long int i;
+
+  TEST_COMPARE (ulabs (LONG_MAX), LONG_MAX);
+  TEST_COMPARE (ulabs (LONG_MIN), (unsigned long int)LONG_MAX + 1);
+  TEST_COMPARE (ulabs (-1), 1);
+  TEST_COMPARE (ulabs (0), 0);
+  TEST_COMPARE (ulabs (1), 1);
+
+  for (i = LONG_MIN + 1; i < LONG_MIN + INT_MAX; i += LARGE_PRIME)
+    TEST_COMPARE (ulabs (i), -i);
+
+  for (i = LONG_MAX - INT_MAX; i < LONG_MAX - LARGE_PRIME;
+       i += LARGE_PRIME)
+    TEST_COMPARE (ulabs (i), i);
+
+  for (i = INT_MIN + 1; i < 0; i += LARGE_PRIME)
+    TEST_COMPARE (ulabs (i), -i);
+
+  for (i = 0; i <= INT_MAX - LARGE_PRIME; i += LARGE_PRIME)
+    TEST_COMPARE (ulabs (i), i);
+
+  return EXIT_SUCCESS;
+}
+
+#include <support/test-driver.c>