Committed as obvious. Without this, mmix-knuth-mmixware exited with 2256, likely a return-address left over in the return-value-register. I used __builtin_exit just to avoid declarations or includes; the default implicit declaration apparently incompatible with this use. I saw nothing in the related conversation thread that this was anything but an oversight. Of course this might have caused an unintended failure mistaken for a valid test-case, but Occam says that's overthinking.
testsuite: * gcc.dg/webizer.c (main): Add missing exit call. Index: gcc.dg/webizer.c =================================================================== --- gcc.dg/webizer.c (revision 192651) +++ gcc.dg/webizer.c (working copy) @@ -32,4 +32,5 @@ configure2() main() { configure2(); + __builtin_exit (0); } brgds, H-P