https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111956
--- Comment #18 from Gaius Mulley <gaius at gcc dot gnu.org> --- Created attachment 57110 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57110&action=edit Work in progress fix Many thanks for the config.gcc hints! It now builds on gcc120 and gcc135 with the work in progress patch. Currently it lacks the -mabi= handling in gm2spec.cc, I've not revisited this file yet and so any #ifdef M2C_LONGREAL (is now always) undefined. However cc1gm2 uses the config.gcc and tm_defines and a summary of results on gcc120: === gm2 Summary === # of expected passes 12962 # of unexpected failures 24 # of unresolved testcases 6 and on gcc135: === gm2 Summary === # of expected passes 12974 # of unexpected failures 18 I think the -mabi= should just override the default settings - and hopefully the results will improve.