https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124124
--- Comment #1 from Tomasz Kamiński <tkaminsk at gcc dot gnu.org> ---
I think that following two are missing:
// { dg-require-atomic-cmpxchg-word "" }
// { dg-add-options libatomic }
Could you check if following change fixes it:
diff --git a/libstdc++-v3/testsuite/29_atomics/atomic/cons/zero_padding.cc
b/libstdc++-v3/testsuite/29_atomics/atomic/cons/zero_padding.cc
index ad48d66de3a..3c8a4a8f428 100644
--- a/libstdc++-v3/testsuite/29_atomics/atomic/cons/zero_padding.cc
+++ b/libstdc++-v3/testsuite/29_atomics/atomic/cons/zero_padding.cc
@@ -1,6 +1,6 @@
// { dg-do run { target c++11 } }
-// { dg-require-thread-fence "" }
-// { dg-add-options no_pch }
+// { dg-require-atomic-cmpxchg-word "" }
+// { dg-add-options libatomic }
#include <atomic>
#include <cstring>
