https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113707
--- Comment #2 from Zhendong Su <zhendong.su at inf dot ethz.ch> --- Another related test for -O3 (only): [555] % gcctk -O3 small.c during GIMPLE pass: cunroll small.c: In function ‘main’: small.c:14:5: internal compiler error: Segmentation fault 14 | int main() { | ^~~~ 0x1161623 crash_signal ../../gcc-trunk/gcc/toplev.cc:317 0x7fa97fd5308f ??? /build/glibc-wuryBv/glibc-2.31/signal/../sysdeps/unix/sysv/linux/x86_64/sigaction.c:0 0xda0c28 extract_ops_from_tree(tree_node*, tree_code*, tree_node**, tree_node**, tree_node**) ../../gcc-trunk/gcc/gimple-expr.cc:530 0xd980e0 gimple_build_assign(tree_node*, tree_node*) ../../gcc-trunk/gcc/gimple.cc:454 0x137c91c eliminate_dom_walker::eliminate_cleanup(bool) ../../gcc-trunk/gcc/tree-ssa-sccvn.cc:7494 0x13917db do_rpo_vn_1 ../../gcc-trunk/gcc/tree-ssa-sccvn.cc:8720 0x13923b3 do_rpo_vn(function*, edge_def*, bitmap_head*, bool, bool, bool, vn_lookup_kind) ../../gcc-trunk/gcc/tree-ssa-sccvn.cc:8749 0x12df179 tree_unroll_loops_completely ../../gcc-trunk/gcc/tree-ssa-loop-ivcanon.cc:1554 0x12df2b3 execute ../../gcc-trunk/gcc/tree-ssa-loop-ivcanon.cc:1673 0x12df2b3 execute ../../gcc-trunk/gcc/tree-ssa-loop-ivcanon.cc:1663 Please submit a full bug report, with preprocessed source (by using -freport-bug). Please include the complete backtrace with any bug report. See <https://gcc.gnu.org/bugs/> for instructions. [556] % [556] % cat small.c int a, b, c, d, e, f, g, h, j, k, l; void n() { while (c) if (1) { for (h = 5; h; h--) { int m = e % 2; d = ~g || h ^ m / -1; if (h > 5) e = k; } return; } } int main() { if (a) for (int i = 0; i < 2; i++) { for (f = 1; f < 6; f++) for (c = 7; c >= 0; c--) if (l) b = 0; n(); } return 0; }