https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115872
--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-12 branch has been updated by hongtao Liu <liuho...@gcc.gnu.org>: https://gcc.gnu.org/g:e1427b39d28f382d21e7a0ea1714b3250e0a6e5d commit r12-10617-ge1427b39d28f382d21e7a0ea1714b3250e0a6e5d Author: liuhongt <hongtao....@intel.com> Date: Fri Jul 12 09:39:23 2024 +0800 Fix SSA_NAME leak due to def_stmt is removed before use_stmt. - _5 = __atomic_fetch_or_8 (&set_work_pending_p, 1, 0); - # DEBUG old => (long int) _5 + _6 = .ATOMIC_BIT_TEST_AND_SET (&set_work_pending_p, 0, 1, 0, __atomic_fetch_or_8); + # DEBUG old => NULL # DEBUG BEGIN_STMT - # DEBUG D#2 => _5 & 1 + # DEBUG D#2 => NULL ... - _10 = ~_5; - _8 = (_Bool) _10; - # DEBUG ret => _8 + _8 = _6 == 0; + # DEBUG ret => (_Bool) _10 confirmed. convert_atomic_bit_not does this, it checks for single_use and removes the def, failing to release the name (which would fix this up IIRC). Note the function removes stmts in "wrong" order (before uses of LHS are removed), so it requires larger surgery. And it leaks SSA names. gcc/ChangeLog: PR target/115872 * tree-ssa-ccp.cc (convert_atomic_bit_not): Remove use_stmt after use_nop_stmt is removed. (optimize_atomic_bit_test_and): Ditto. gcc/testsuite/ChangeLog: * gcc.target/i386/pr115872.c: New test. (cherry picked from commit a8209237dc46dc4db7d9d8e3807e6c93734c64b5)
