[PATCH] D152278: [SCEV] Compute SCEV for ashr(add(shl(x, n), c), m) instr triplet

[Vedant Paranjape via Phabricator via llvm-commits]

vedant-amd marked 3 inline comments as done.
vedant-amd added inline comments.


================
Comment at: llvm/lib/Analysis/ScalarEvolution.cpp:7893
+          // type, so create a new Constant with type same as TruncTy
+          int64_t AddOperand = AddOperandCI->getSExtValue();
+          const SCEV *AddConstant = getConstant(TruncTy, AddOperand >> AShrAmt);
----------------
efriedma wrote:
> vedant-amd wrote:
> > efriedma wrote:
> > > Is there some reason to expect that "c" fits into an int64_t?
> > Right, I need to add a check like this I guess ?
> > 
> > ```
> >       if (CI->getValue().uge(BitWidth))
> > 
> > ```
> That doesn't look like the right check.
> 
> If it were necessary, you could use isIntN or something like that.  But you should just be able to just do the math in APInt: `AddOperandCI->getValue().ashr(AShrAmt)` or something like that.
I have made the following change, please take a look once.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D152278/new/

https://reviews.llvm.org/D152278