https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115399
--- Comment #8 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-13 branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:0fa5c0340fa6b897e1fd7c62a107e93eb05fb557 commit r13-9082-g0fa5c0340fa6b897e1fd7c62a107e93eb05fb557 Author: Jonathan Wakely <jwak...@redhat.com> Date: Mon Jun 10 14:08:16 2024 +0100 libstdc++: Fix std::tr2::dynamic_bitset shift operations [PR115399] The shift operations for dynamic_bitset fail to zero out words where the non-zero bits were shifted to a completely different word. For a right shift we don't need to sanitize the unused bits in the high word, because we know they were already clear and a right shift doesn't change that. libstdc++-v3/ChangeLog: PR libstdc++/115399 * include/tr2/dynamic_bitset (operator>>=): Remove redundant call to _M_do_sanitize. * include/tr2/dynamic_bitset.tcc (_M_do_left_shift): Zero out low bits in words that should no longer be populated. (_M_do_right_shift): Likewise for high bits. * testsuite/tr2/dynamic_bitset/pr115399.cc: New test. (cherry picked from commit bd3a312728fbf8c35a09239b9180269f938f872e)
