[PATCH] D14792: Have 'optnone' respect -fast-isel=false

[Daniel Sanders via llvm-commits]

dsanders added a comment.

In http://reviews.llvm.org/D14792#293634, @probinson wrote:

> In http://reviews.llvm.org/D14792#293572, @echristo wrote:
>
> > Just make it an enum ala FloatABI with a Default, SelectionDAG, FastISel
> >  and use that everywhere?
> >
> > -eric
>
>
> "Everywhere" is exactly two places, hardly seems worth the trouble.  Maybe rename the flag to "O0UsesFastISel" instead? which then can be used directly in both LLVMTargetMachine and OptLevelChanger with obviously consistent semantics.


Given the current choice of SelectionDAG vs FastISel, I agree with Paul that this isn't worth the trouble. I think Eric is accounting for the addition of Global ISel in the near future which would presumably add a third choice to the enum he's requesting. If that is the reason, then I'd suggest leaving that for Global ISel since it's going to have to replace the -fast-isel option with an enum based option anyway.

I also agree with the renaming. FWIW, I was going to suggest 'CanUseFastISel' but I think 'O0UsesFastISel' or maybe 'O0WantsFastISel' is better.


http://reviews.llvm.org/D14792