https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93253
--- Comment #6 from Steve Kargl <sgk at troutmask dot apl.washington.edu> --- On Tue, Jan 14, 2020 at 11:18:45AM +0000, pinskia at gcc dot gnu.org wrote: > ---- CUT ---- > So using an undocumented extension .... The 'X' extension was documented, but I doubt anyone reads documentation. Prior to my patch, the docs read 6.1.10 BOZ literal constants ... As an extension, GNU Fortran allows hexadecimal BOZ literal constants to be specified using the 'X' prefix, in addition to the standard 'Z' prefix. The BOZ literal can also be specified by adding a suffix to the string, for example, 'Z'ABC'' and ''ABC'Z' are equivalent. ... The docs now read ... As a deprecated extension, GNU Fortran allows hexadecimal BOZ literal constants to be specified using the 'X' prefix. The BOZ literal constant can also be specified by adding a suffix to the string, for example, 'Z'ABC'' and ''ABC'X' are equivalent. ... > Basically BOZ is finally standardized in Fortran2018 and the NAS benchmark > could be re-written in a standard format instead ... The first part is indeed true. User fixing invalid Fortran code to use standard conforming syntax is encouraged.