[PATCH] D140087: [X86] Replace (31/63 -/^ X) with (NOT X) and ignore (32/64 ^ X) when computing shift count

[Noah Goldstein via Phabricator via llvm-commits]

goldstein.w.n marked 2 inline comments as done.
goldstein.w.n added inline comments.


================
Comment at: llvm/lib/Target/X86/X86ISelDAGToDAG.cpp:4023-4025
+      // ISelLowering will convert this to NOT already.
+      if (ConstValOp->isAllOnes())
+        return false;
----------------
lebedev.ri wrote:
> Since we are already here, why not just do it ourselves?
> That would be less LOC even.
Done.


================
Comment at: llvm/lib/Target/X86/X86ISelDAGToDAG.cpp:4028
+      NewShiftAmt = CurDAG->getNOT(DL, Add0C == nullptr ? Add0 : Add1, OpVT);
+
+      insertDAGNode(*CurDAG, OrigShiftAmt, NewShiftAmt);
----------------
lebedev.ri wrote:
> Remove newline
Done.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D140087/new/

https://reviews.llvm.org/D140087