https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126988
--- Comment #2 from Zhendong Su <zhendong.su at inf dot ethz.ch> --- Another reproducer that is smaller and doesn't need the extra flags: Compiler Explorer: https://godbolt.org/z/oP798bnr5 [508] % gcctk -v Using built-in specs. COLLECT_GCC=gcctk COLLECT_LTO_WRAPPER=/local/home/suz/suz-local/software/local/gcc-trunk/bin/../libexec/gcc/x86_64-pc-linux-gnu/17.0.0/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++,lto --disable-werror --disable-multilib Thread model: posix Supported LTO compression algorithms: zlib gcc version 17.0.0 20261015 (experimental) [master r17-1628-gd1c12591336] (GCC) [509] % [509] % gcctk -O3 -c small.c during GIMPLE pass: slp small.c: In function ‘j’: small.c:9:6: internal compiler error: in check_loop_closed_ssa_def, at tree-ssa-loop-manip.cc:664 9 | void j() { | ^ 0x2867b0b internal_error(char const*, ...) ../../gcc-trunk/gcc/diagnostic-global-context.cc:787 0xa85107 fancy_abort(char const*, int, char const*) ../../gcc-trunk/gcc/diagnostics/context.cc:1813 0x906918 check_loop_closed_ssa_def ../../gcc-trunk/gcc/tree-ssa-loop-manip.cc:664 0x141fed7 check_loop_closed_ssa_bb ../../gcc-trunk/gcc/tree-ssa-loop-manip.cc:689 0x1420366 verify_loop_closed_ssa(bool, loop*) ../../gcc-trunk/gcc/tree-ssa-loop-manip.cc:714 0x1420366 verify_loop_closed_ssa(bool, loop*) ../../gcc-trunk/gcc/tree-ssa-loop-manip.cc:698 0x1120df9 execute_function_todo ../../gcc-trunk/gcc/passes.cc:2118 0x11214fe execute_todo ../../gcc-trunk/gcc/passes.cc:2152 /local/home/suz/suz-local/software/local/gcc-trunk/bin/../libexec/gcc/x86_64-pc-linux-gnu/17.0.0/cc1 -quiet -I /usr/local/include -I /local/suz-local/software/local/include -imultiarch x86_64-linux-gnu -iprefix /local/home/suz/suz-local/software/local/gcc-trunk/bin/../lib/gcc/x86_64-pc-linux-gnu/17.0.0/ small.c -quiet -dumpbase small.c -dumpbase-ext .c -mtune=generic -march=x86-64 -O3 -o /tmp/ccRnqtSJ.s 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. [510] % [510] % cat small.c int printf(const char *, ...); struct { int a; int b; int c; int d; } h; int f, g; void j() { int k, l; do { h.a = h.b = g + 1; h.c = 2 * l + 1; h.d = 2 * k + 1; printf("0"); } while (f); h.c = 2 * l + 1; h.d = 2 * k + 1; }
