https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115929
--- Comment #1 from Zhendong Su <zhendong.su at inf dot ethz.ch> --- Another likely related test. Compiler Explorer: https://godbolt.org/z/o7Wrd7P66 [551] % 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/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 20240714 (experimental) (GCC) [552] % [552] % gcctk -O2 -fno-gcse -fschedule-insns -fno-guess-branch-probability -fno-tree-fre -fno-tree-ch small.c during RTL pass: late_combine small.c: In function ‘main’: small.c:42:1: internal compiler error: in compare_nodes, at splay-tree-utils.tcc:958 42 | } | ^ 0x24979f5 internal_error(char const*, ...) ../../gcc-trunk/gcc/diagnostic-global-context.cc:491 0xa462c6 fancy_abort(char const*, int, char const*) ../../gcc-trunk/gcc/diagnostic.cc:1725 0xa30b0f rootless_splay_tree<default_splay_tree_accessors_with_parent<rtl_ssa::insn_info::order_node*> >::compare_nodes(rtl_ssa::insn_info::order_node*, rtl_ssa::insn_info::order_node*) ../../gcc-trunk/gcc/splay-tree-utils.tcc:958 0xa30b0f rootless_splay_tree<default_splay_tree_accessors_with_parent<rtl_ssa::insn_info::order_node*> >::compare_nodes(rtl_ssa::insn_info::order_node*, rtl_ssa::insn_info::order_node*) ../../gcc-trunk/gcc/splay-tree-utils.tcc:944 0xa30b0f rtl_ssa::insn_info::slow_compare_with(rtl_ssa::insn_info const&) const ../../gcc-trunk/gcc/rtl-ssa/insns.cc:88 0x2389403 rtl_ssa::insn_info::compare_with(rtl_ssa::insn_info const*) const ../../gcc-trunk/gcc/rtl-ssa/member-fns.inl:550 0x2389403 operator() ../../gcc-trunk/gcc/rtl-ssa/accesses.cc:549 0x2389403 lookup<rtl_ssa::lookup_clobber(rtl_ssa::clobber_tree&, rtl_ssa::insn_info*)::<lambda(rtl_ssa::clobber_info*)> > ../../gcc-trunk/gcc/splay-tree-utils.tcc:536 0x238ab8a rtl_ssa::lookup_clobber(rooted_splay_tree<splay_tree_accessors_with_parent<default_splay_tree_accessors_with_parent<rtl_ssa::clobber_info*> > >&, rtl_ssa::insn_info*) ../../gcc-trunk/gcc/rtl-ssa/accesses.cc:551 0x238ab8a rtl_ssa::function_info::add_clobber(rtl_ssa::clobber_info*, rtl_ssa::clobber_group*) ../../gcc-trunk/gcc/rtl-ssa/accesses.cc:661 0x238e36c rtl_ssa::function_info::add_def(rtl_ssa::def_info*) ../../gcc-trunk/gcc/rtl-ssa/accesses.cc:950 0x239227a rtl_ssa::function_info::apply_changes_to_insn(rtl_ssa::insn_change&, hash_set<rtl_ssa::def_info*, false, default_hash_traits<rtl_ssa::def_info*> >&) ../../gcc-trunk/gcc/rtl-ssa/changes.cc:688 0x2394de4 rtl_ssa::function_info::change_insns(array_slice<rtl_ssa::insn_change*>) ../../gcc-trunk/gcc/rtl-ssa/changes.cc:888 0x233966a run ../../gcc-trunk/gcc/late-combine.cc:452 0x233966a combine_into_uses ../../gcc-trunk/gcc/late-combine.cc:683 0x2339db7 execute ../../gcc-trunk/gcc/late-combine.cc:711 0x2339db7 execute ../../gcc-trunk/gcc/late-combine.cc:760 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. [553] % [553] % cat small.c int printf(const char *, ...); int a[6], b, c; char d, l; struct { char e; int f; int : 8; long g; long h; } i[1][9] = {0}; unsigned j; void n(char p) { b = b >> 8 ^ a[b ^ p]; } int main() { int k, o; while (b) { k = 0; for (; k < 9; k++) { b = b ^ a[l]; n(j); if (o) printf(&d); long m = i[c][k].f; b = b >> 8 ^ a[l]; n(m >> 32); n(m); if (o) printf("%d", d); b = b >> 8 ^ l; n(2); n(0); if (o) printf(&d); b = b ^ a[l]; n(i[c][k].g >> 2); n(i[c][k].g); if (o) printf(&d); printf("%d", i[c][k].f); } } return 0; }
