[PATCH] stdc_rotate_left-tests: pacify -Woverflow

Problem found with gcc 16.1.1 20260515 (Red Hat 16.1.1-2) on i686.
* tests/test-stdc_rotate_left.c (test_stdc_rotate_left_ul):
* tests/test-stdc_rotate_right.c (test_stdc_rotate_right_ul): Use
preprocessor-time check, not a potentially runtime check, to see
whether to use 32- or 64-bit tests.  This pacifies gcc -Woverflow.
Include <limits.h> to get ULONG_MAX.
---
 ChangeLog                      | 10 ++++++++++
 tests/test-stdc_rotate_left.c  | 11 +++++++----
 tests/test-stdc_rotate_right.c | 11 +++++++----
 3 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index fe2bd22dd8..4d08951061 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2026-08-12  Paul Eggert  <[email protected]>
+
+	stdc_rotate_left-tests: pacify -Woverflow
+	Problem found with gcc 16.1.1 20260515 (Red Hat 16.1.1-2) on i686.
+	* tests/test-stdc_rotate_left.c (test_stdc_rotate_left_ul):
+	* tests/test-stdc_rotate_right.c (test_stdc_rotate_right_ul): Use
+	preprocessor-time check, not a potentially runtime check, to see
+	whether to use 32- or 64-bit tests.  This pacifies gcc -Woverflow.
+	Include <limits.h> to get ULONG_MAX.
+
 2026-08-12  Bruno Haible  <[email protected]>
 
 	omap-c++: Avoid clang UBSAN runtime errors.
diff --git a/tests/test-stdc_rotate_left.c b/tests/test-stdc_rotate_left.c
index 64cc5b8477..10723d4afc 100644
--- a/tests/test-stdc_rotate_left.c
+++ b/tests/test-stdc_rotate_left.c
@@ -21,6 +21,8 @@
 /* Specification.  */
 #include <stdbit.h>
 
+#include <limits.h>
+
 #include "macros.h"
 
 #define TEST_CASE(type, function, value, shift, expect)         \
@@ -437,10 +439,11 @@ test_stdc_rotate_left_ui (void)
 static void
 test_stdc_rotate_left_ul (void)
 {
-  if (sizeof 0ul < sizeof 0ull)
-    TEST_CASES_32 (unsigned long int, stdc_rotate_left_ul);
-  else
-    TEST_CASES_64 (unsigned long int, stdc_rotate_left_ul);
+#if ULONG_MAX >> 31 == 1
+  TEST_CASES_32 (unsigned long int, stdc_rotate_left_ul);
+#else
+  TEST_CASES_64 (unsigned long int, stdc_rotate_left_ul);
+#endif
 }
 
 static void
diff --git a/tests/test-stdc_rotate_right.c b/tests/test-stdc_rotate_right.c
index 715a447c19..0ffdd928d5 100644
--- a/tests/test-stdc_rotate_right.c
+++ b/tests/test-stdc_rotate_right.c
@@ -21,6 +21,8 @@
 /* Specification.  */
 #include <stdbit.h>
 
+#include <limits.h>
+
 #include "macros.h"
 
 #define TEST_CASE(type, function, value, shift, expect)         \
@@ -437,10 +439,11 @@ test_stdc_rotate_right_ui (void)
 static void
 test_stdc_rotate_right_ul (void)
 {
-  if (sizeof 0ul < sizeof 0ull)
-    TEST_CASES_32 (unsigned long int, stdc_rotate_right_ul);
-  else
-    TEST_CASES_64 (unsigned long int, stdc_rotate_right_ul);
+#if ULONG_MAX >> 31 == 1
+  TEST_CASES_32 (unsigned long int, stdc_rotate_right_ul);
+#else
+  TEST_CASES_64 (unsigned long int, stdc_rotate_right_ul);
+#endif
 }
 
 static void
-- 
2.55.0