https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100499
--- Comment #22 from Jeffrey A. Law <law at gcc dot gnu.org> --- I have vague memories of it, but it wasn't my code. It was actually Craig Burley. It's original purpose was merely to allow converting *_DIV_EXPR into EXACT_DIV_EXPR which presumably was important for some g77 cases way back then.
