[PATCH] D31801: Performance enhancements for Cavium ThunderX2 T99

[Kristof Beyls via Phabricator via llvm-commits]

kristof.beyls added inline comments.


================
Comment at: lib/Target/AArch64/AArch64ISelLowering.cpp:7624
+  case AArch64Subtarget::ThunderX2T99:
+  case AArch64Subtarget::ThunderXT88:
+    if (VT.isFloatingPoint() && VT.isVector())
----------------
steleman wrote:
> rengolin wrote:
> > This smells like a target feature. :)
> I can definitely re-write it as a TargetFeature.
> 
my 2 cents, hoping someone with more experience in this area can help further:

IIUC, the effect of this change is that also for vector types, this function now returns true, when targeting ThunderX2T99 or ThunderXT88?

I can see that for different cores/micro-architectures a different response could be wanted here, also depending on the types involved.
Since the answer could be different dependent on the type, I'm guessing that this won't map nicely to a target feature.
Maybe this information needs to become a subtarget hook somehow?

Also, please upload the next iteration of this patch with lots of context (e.g. git diff -U9999) - that makes reviewing it a bit easier.




Repository:
  rL LLVM

https://reviews.llvm.org/D31801