[PATCH] D70009: [ARM][ReachingDefs] RDA in LoLoops

[Sam Parker via Phabricator via llvm-commits]

samparker marked 2 inline comments as done.
samparker added inline comments.


================
Comment at: llvm/lib/CodeGen/ReachingDefAnalysis.cpp:219
+
+bool ReachingDefAnalysis::hasSameReachingDef(MachineInstr *A, MachineInstr *B,
+                                             int PhysReg) {
----------------
SjoerdMeijer wrote:
> I am a bit confused, this seems to be done in D70240?
Yes, I moved it over and will rebase once that patch is in.


================
Comment at: llvm/lib/CodeGen/ReachingDefAnalysis.cpp:233
+  LiveRegs.addLiveOuts(*MBB);
+  if (LiveRegs.contains(PhysReg))
+    return true;
----------------
dmgreen wrote:
> Hmm. You don't know if this is the _same_ PhysReg, right? It could be a different def of the same register?
> 
> That would still fit in with how RDA works, but is kind of mixing together liveness and reachability.
> 
> Yeah OK. I think this expands reaching defs in a sensible direction.
True, this doesn't say whether a //value// is used, just whether a register is live at some point afterwards.


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  https://reviews.llvm.org/D70009/new/

https://reviews.llvm.org/D70009