[PATCH] D111810: [DebugInfo][LSR] Add more stringent checks on IV selection and cached dbg.value location-op SCEVs

[Chris Jackson via Phabricator via llvm-commits]

chrisjackson added inline comments.


================
Comment at: llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp:6238-6243
+      // A SCEVUknown type is an entirely unknown SCEV value, represented only
+      // as an llvm value. At this point if the value hasn't been optimised away
+      // a salvage is unnecessary. If it has been then no progress can be made.
+      if (isa<SCEVUnknown>(DVIRec.SCEV))
+        continue;
+
----------------
StephenTozer wrote:
> Should we check for an undef SCEV here as well, or is the SCEV expression guaranteed to not be undef at this point?
This additional check was unnecessary, as DbgGatherSalvagableDVI() will prevent SCEVUknown or SCEVs containing an undef from being cached.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D111810/new/

https://reviews.llvm.org/D111810