https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120236
Bug ID: 120236 Summary: wrong code at -O{s,2,3} with "-fno-tree-fre -fipa-pta" on x86_64-linux-gnu Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: ipa Assignee: unassigned at gcc dot gnu.org Reporter: zhendong.su at inf dot ethz.ch Target Milestone: --- Compiler Explorer: https://godbolt.org/z/jjrdsPYTn This appears to affect all versions, so perhaps a known issue? [507] % gcctk -v Using built-in specs. COLLECT_GCC=gcctk COLLECT_LTO_WRAPPER=/local/suz-local/software/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/16.0.0/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 16.0.0 20250512 (experimental) (GCC) [508] % [508] % gcctk -O3 small.c; ./a.out [509] % [509] % gcctk -O3 -fno-tree-fre -fipa-pta small.c [510] % ./a.out Aborted [511] % [511] % cat small.c int a, b, *c = &b; int main() { while (a) { int ***d; *d = &c; a = ***d; if (b) __builtin_abort(); } *c = 1; if (!b) __builtin_abort(); return 0; }