https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117480
Bug ID: 117480 Summary: wrong code at -O1 and above on x86_64-linux-gnu Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: zhendong.su at inf dot ethz.ch Target Milestone: --- This appears to be a recent regression as it doesn't reproduce with 14.2 and earlier. Compiler Explorer: https://godbolt.org/z/91fxrzE49 [607] % gcctk -v Using built-in specs. COLLECT_GCC=gcctk COLLECT_LTO_WRAPPER=/local/home/suz/suz-local/software/local/gcc-trunk/bin/../libexec/gcc/x86_64-pc-linux-gnu/15.0.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../gcc-trunk/configure --disable-bootstrap --enable-checking=yes --prefix=/local/suz-local/software/local/gcc-trunk --enable-sanitizers --enable-languages=c,c++ --disable-werror --enable-multilib Thread model: posix Supported LTO compression algorithms: zlib gcc version 15.0.0 20241107 (experimental) (GCC) [608] % [608] % gcctk -O0 small.c; ./a.out [609] % [609] % gcctk -O1 small.c [610] % ./a.out Aborted [611] % [611] % cat small.c int c = 0x1FF; int main() { if (((c ^ 0xFF) & 0xFF) != 0) __builtin_abort(); return 0; }