[PATCH] D30225: [LIR] re-enable generation of memmove with runtime checks

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

It looks like there aren't any calls to createLoopVersioningIdiomPass()?

Oh, also, performance numbers would be nice at some point.



================
Comment at: llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp:1111
+  if (Instruction *In = dyn_cast<Instruction>(NumBytes))
+    if (Value *Simp = SimplifyInstruction(In, *DL, TLI, DT))
+      NumBytes = Simp;
----------------
kparzysz wrote:
> efriedma wrote:
> > Why do we need to call SimplifyInstruction here?
> I guess back when this was written, it made some difference.  I don't remember what it was though.  Do you think it's unnecessary now?
I can't see why it would make a difference... SimplifyInstruction probably won't simplify a non-trivial SCEV expression to a ConstantInt, and the rest will get cleaned up by instcombine later.


Repository:
  rL LLVM

https://reviews.llvm.org/D30225