https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90181
--- Comment #10 from Elliott M <ehem+gccbugs at m5p dot com> --- Eyes must have glazed over when trying to find other reports. 105048 is indeed a duplicate. Another option might be "R<register_name>" for architectures which haven't already grabbed "R" for something else. I notice Clang though doesn't appear to have "R" implemented which seems to suggest actual uses of the current definition of "R" are rare. There are multiple calls for this feature, any chance of an implementation?
