On Mon, May 25, 2020 at 02:14:02PM +0200, Richard Biener wrote: > On Mon, May 25, 2020 at 1:10 PM guojiufu <guoji...@linux.ibm.com> wrote: > Since a new flag is not needed to fix the regression please avoid > adding -fcomplete-unroll-loops. > > For -frtl-unroll-loops you should be able to use
Erm. That *is* a new command-line option (the internal flags I do not care about so much: new implementation details are *good*). And a new name that is a mistake in my opinion, for many reasons (users do not know and should not have to care about "rtl"; the name is not descriptive; it is useless churn, it is not the same name as we have had for decades now; it is adding a new option for a future where we will do most unrolling at gimple level, a future we do not know will ever exist, and we do not know what that will look like anyway; it is an extra level of indirection (in the name)). We should not have an -frtl-unroll-loops if we do not have a -ftree-unroll-loops (or whatever). Unrolling early is not a good idea in general (the problems with the very trivial complete unrolling case just underline that). But we *should* know which code we expect to unroll later, for better costing. Adding names like "rtl-unroll-loops" only stands in the way of getting a better design here. Segher
