[PATCH] D142783: [InstCombine][LV][WIP] Fold (add (zext (add X, -1)), 1) -> (zext X) if X is non-zero.

Mon Jan 30 12:31:57 PST 2023

spatel added a comment.

In D142783#4091597 <https://reviews.llvm.org/D142783#4091597>, @craig.topper wrote:

> Should I proceed with this patch?

Seems ok to me. Add an alive link to the patch description:
https://alive2.llvm.org/ce/z/NsRDwX

================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp:979
+  // Fold (add (zext (add X, -1)), 1) -> (zext X) if X is non-zero.
+  // FIXME: There's a general form for any constant on the outer add.
+  if (C->isOne()) {
----------------
FIXME -> TODO

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D142783/new/

https://reviews.llvm.org/D142783