https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100183
--- Comment #6 from Iain Sandoe <iains at gcc dot gnu.org> --- (In reply to anlauf from comment #5) > (In reply to Iain Sandoe from comment #4) > > gcc304 is the Apple M1 machine. The GCC support there is highly > > experimental and not in master -- please note that there are known issues > > with the implementation. > > > > see : https://github.com/iains/gcc-darwin-arm64/issues > > So rather a target than a fortran issue? The fortran folks have fixed a number of cases recently where the FE was providing bad information to the ME .. which doesn't cause problems to most targets, but did to aarch64-darwin. I cannot rule out that this is another case in that category (but not had a chance to analyse it yet).