https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121570
--- Comment #8 from kargls at comcast dot net --- (In reply to Richard Biener from comment #6) > As gfortran uses the C standard library IEEE interfacing, if that interface > agrees with the Fortran language requirement we can rely on a correct > implementation of the C standard library. Having a testcase in the > testsuite pointing out wrong behavior therein would be a good thing to have, > of course. AFAIK, both C and Fortran try to conform to ISO/IEC 60559:2020. Whether libc/libm on any particular operating system conforms is the question. I know FreeBSD strives to conform. Its libm is based on fdlibm, which openbsd and netbsd also use. I have no idea if AIX (in particular its double-double FP type) or MacOS adhere to ISO/IEC 60559:2020.