[PATCH] D127281: [Greedy RegAlloc] Fix the handling of split register in last chance re-coloring.

[Serguei Katkov via Phabricator via llvm-commits]

skatkov added inline comments.


================
Comment at: llvm/lib/CodeGen/RegAllocGreedy.cpp:1907
       std::tie(LI, PhysReg) = RecolorStack[I];
-      Matrix->assign(*LI, PhysReg);
+      if (!LI->empty() && !MRI->reg_nodbg_empty(LI->reg()))
+        Matrix->assign(*LI, PhysReg);
----------------
arsenm wrote:
> Why are both checks necessary? Why isn't LI->empty sufficient?
Because after the split, the live interval of original virtual register does not become empty. It just remains as is.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D127281/new/

https://reviews.llvm.org/D127281