[PATCH] D91358: [ARM][RegAlloc] Add t2LoopEndDec

[Bjorn Pettersson via Phabricator via llvm-commits]

bjope added inline comments.


================
Comment at: llvm/lib/CodeGen/PHIElimination.cpp:452
+             "Expected operand 0 to be a reg def!");
+      SrcRegDef->getOperand(0).setReg(IncomingReg);
+      continue;
----------------
This is only valid if there are no other uses of SrcReg (no anywhere else, and not in the current MBB that we are eliminating PHI nodes inside, such as another PHI node in MBB).

Haven't analyzed it more closely than that. But I don't know if it can be generally guaranteed that the def in an UnspillableTerminator only has a single use. Is such a rule guaranteed here (or even feasible)?



CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D91358/new/

https://reviews.llvm.org/D91358