https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82479 --- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Was added to LLVM back in 2012: http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20121119/156272.html Again I don't know how useful it is compared to the compile time that it would take.