Remove invalid assert in DAGTypeLegalizer::RemapValue

There is a comment at the top of DAGTypeLegalizer::PerformExpensiveChecks
which, in part, says:

  // Note that these invariants may not hold momentarily when processing a node:
  // the node being processed may be put in a map before being marked Processed.

Unfortunately, this assert would be valid only if the above-mentioned invariant
held unconditionally. This was causing llc to assert when, in fact,
everything was fine.

Thanks to Richard Sandiford for investigating this issue!

Fixes PR16562.

llvm-svn: 186338

1 files changed, 4 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
index ef7966209e2..fd770d140b5 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
@@ -615,7 +615,10 @@ void DAGTypeLegalizer::RemapValue(SDValue &N) {
     // replaced with other values.
     RemapValue(I->second);
     N = I->second;
-    assert(N.getNode()->getNodeId() != NewNode && "Mapped to new node!");
+
+    // Note that it is possible to have N.getNode()->getNodeId() == NewNode at
+    // this point because it is possible for a node to be put in the map before
+    // being processed.
   }
 }