[PATCH] D28694: Hexagon-specific loop idiom recognition

[Krzysztof Parzyszek via Phabricator via llvm-commits]

kparzysz added a comment.

In https://reviews.llvm.org/D28694#645883, @efriedma wrote:

> If we wanted to allow targets to add target-specific extensions, we could add a function to TargetMachine which takes a PassManagerBuilder, and make clang call it.  And it's easy enough to add extension points if we need them.


That's actually a good point!

> That said, I'm not sure that's really relevant for your particular use-case; the transformation presented here is basically target-independent.  The only issue is that there isn't a target-independent equivalent to `hexagon_M4_pmpyw` (but equivalent instructions do exist on many targets; x86 has `PCLMULQDQ`, ARM has `VMULL.P64`, etc.).

True, but there is other stuff in that file as well that only applies to Hexagon.  Plus posting of this patch was motivated by a post on llvm-dev asking about this exact thing (i.e. target-specific loop idioms).


Repository:
  rL LLVM

https://reviews.llvm.org/D28694