https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120661
--- Comment #4 from Zhendong Su <zhendong.su at inf dot ethz.ch> --- Here is another likely related test (which is also valid) that only hangs at -Os. Compiler Explorer: https://godbolt.org/z/rMWKPxdos [512] % 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/16.0.0/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 16.0.0 20250616 (experimental) (GCC) [513] % [513] % time gcctk -O2 small.c real 0m0.217s user 0m0.069s sys 0m0.014s [514] % time gcctk -O3 small.c real 0m0.225s user 0m0.081s sys 0m0.007s [515] % [515] % timeout -s 9 30 gcctk -Os small.c Killed [516] % cat small.c #include <stdarg.h> int e, a, b; int f(int b, ...) { va_list args; va_start(args, b); unsigned c = 1; for (int d; d < b; ++d) c = c ^ 1; return c; } static int fn3(int l, int i, int n) { int j; goto k; r: j = (f(e) + 1641730381) * l + 1189664732 * n + 1064 * i - 1545337304; if (903562339 * j + n >= 0) goto m; goto ac; k: if (0) goto ad; goto t; ad: if (b) goto s; goto r; m: goto ad; t: j = l; l = 800794 * j; goto ad; s: b = 2 * b + 1; if (a + (long)j) goto t; i = n; goto s; ac: } int main() { if (a) if (fn3(-1, 1, -1)) fn3(1, 0, 3); return 0; }
