[PATCH] D48364: [DAG] Don't map a TableId to itself in the ReplacedValues map

[Bjorn Pettersson via Phabricator via llvm-commits]

bjope added inline comments.


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Comment at: lib/CodeGen/SelectionDAG/LegalizeTypes.cpp:578
   if (I != ReplacedValues.end()) {
+    assert(Id != I->second && "Id is mapped to itself.");
     // Use path compression to speed up future lookups if values get multiply
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Maybe an alternative solution could be to allow mapping of a value to itself in ReplacedValues, and then we could simply return Id here when Id==I->second.


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Comment at: lib/CodeGen/SelectionDAG/LegalizeTypes.cpp:658
+      ReplacedValues[FromId] = ToId;
     DAG.ReplaceAllUsesOfValueWith(From, To);
 
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I think we still need to do this replacement even if FromId == ToId, since From.getNode() != To.getNode(), right?


Repository:
  rL LLVM

https://reviews.llvm.org/D48364