https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115782
--- Comment #2 from Zhendong Su <zhendong.su at inf dot ethz.ch> --- Compiler Explorer: https://godbolt.org/z/MeKeYYjYq Another reproducer for -O{2,3} without any other flags: [550] % 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 20240711 (experimental) (GCC) [551] % [551] % gcctk -O2 small.c during RTL pass: late_combine small.c: In function ‘main’: small.c:31:1: internal compiler error: in possibly_queue_changes, at rtl-ssa/changes.cc:378 31 | } | ^ 0x2496472 internal_error(char const*, ...) ../../gcc-trunk/gcc/diagnostic-global-context.cc:491 0xa452f4 fancy_abort(char const*, int, char const*) ../../gcc-trunk/gcc/diagnostic.cc:1725 0xa2f3f3 rtl_ssa::function_info::possibly_queue_changes(rtl_ssa::insn_change&) ../../gcc-trunk/gcc/rtl-ssa/changes.cc:378 0x2393115 rtl_ssa::function_info::change_insns(array_slice<rtl_ssa::insn_change*>) ../../gcc-trunk/gcc/rtl-ssa/changes.cc:779 0x233824a run ../../gcc-trunk/gcc/late-combine.cc:452 0x233824a combine_into_uses ../../gcc-trunk/gcc/late-combine.cc:683 0x2338997 execute ../../gcc-trunk/gcc/late-combine.cc:711 0x2338997 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. [552] % [552] % cat small.c int a, b, c, d, e, f; int main() { int g, i = 4, j = 5; char h = 4; if (c) { j = 0; i = ~(d * 6); if (a) goto k; } g = e; while (a) { long l; while (b) { int m = ~g; o: l = m; char n; int q, p = h; k: h = h % l - (-1 % q & (i || a)); f = (f & p - l % n << h) % b; if (j) continue; h = n; if (f) goto o; } } return 0; }
