https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108007
Bug ID: 108007 Summary: wrong code at -Os and above with "-fno-dce -fno-tree-dce" 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: --- Compiler Explorer: https://godbolt.org/z/51r5Kqr9q It appears to be a regression from 9.*, and affects 10.* till trunk. [599] % 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/13.0.0/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 --with-system-zlib Thread model: posix Supported LTO compression algorithms: zlib gcc version 13.0.0 20221207 (experimental) [master r13-4532-gda7fb32d403] (GCC) [600] % [600] % gcctk -Os -fno-dce -fno-tree-dce small.c [601] % ./a.out Segmentation fault [602] % [602] % cat small.c int a, b, d, e, f = 10000000, h; short c, g; static int *i() { g = f; L: h = e = ~g; g = ~f % g & e; if (!g) goto L; c++; while (g < 1) ; return &a; } static void k() { int *l, m = 2; l = i(); for (; d < 1; d++) m |= *l >= b; } int main() { k(); return 0; }