[RFC] Enabling the HLFIR lowering by default

[h-vetinari]

@jeanPerier

Step 2: The Wait and Clean (aiming for a duration of one LLVM release cycle).

Now that HLFIR is on by default, what interactions (if any) does this have with the rename of flang to flang-new? Last public discussion on this that I’m aware of made it sound like the switch to HLFIR by default would be the last checkbox for the switching the name:

@h-vetinari

@clattner

We should rename the ‘flang-new’ driver to ‘flang’ in the LLVM monorepo, but only when the code matures a bit more. Please follow flang in discourse to track its status.

Did you all agree on some requirements/goals that need to be satisfied, or is this a kind of “when it’s ready” criterion?

@everythingfunctional

I don’t want to speak for @sscalpone , but my understanding from the discussion was “once the HLFIR refactoring is done”. I don’t have a more concrete acceptance criteria than that.

(I guess one could nitpick that I’m equating “finish refactoring” with “switch on by default”; OTOH, once that happens, any further refactoring arguably just becomes regular development to progress the code-base.)