[llvm-dev] Complex proposal v3 + roundtable agenda

[David Greene via llvm-dev]

Florian Hahn <florian_hahn at apple.com> writes:

> Once we have support in the vectorizers, it might be beneficial to use
> the intrinsics even for targets that do not natively support them. I
> think for that cases, adding a pass that lowers them to regular IR
> instructions for targets that do not have dedicated instructions would
> be a great idea. I think we did something similar for the experimental
> reduction intrinsics.

We don't *need* intrinsics to do such lowering.  "Normal" LLVM
instructions with a first-class complex type is similarly lowerable.

I'm not necessarily opposed to intrinsics (especially if we have Simon's
generic matchers available) but I think it's important to be clear what
we're talking about.  Intrtinaics vs. first-class complex types have
different tradeoffs.  With Simon's generic matchers those trade-offs are
less stark to me though.

                  -David