`register` was used as a hint, and things like LLVM have Mem2Reg optimization passes that do a much better job at this sort of promotion. IIRC register was mai

`register` was used as a hint, and things like LLVM have Mem2Reg optimization passes that do a much better job at this sort of promotion. IIRC register was mainly used in cases where hardware were involved, much like the volatile keyword. However unlike volatile, I don't believe register is even considered by compilers these days.