[PATCH] D86963: [DAGCombine] Skip re-visiting EntryToken to avoid compile time explosion

[Ulrich Weigand via Phabricator via llvm-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rG1a25133bcdfe: [DAGCombine] Skip re-visiting EntryToken to avoid compile time explosion (authored by uweigand).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D86963/new/

https://reviews.llvm.org/D86963

Files:
  llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp


Index: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
===================================================================
--- llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -1558,9 +1558,15 @@
       DAG.ReplaceAllUsesWith(N, &RV);
     }
 
-    // Push the new node and any users onto the worklist
-    AddToWorklist(RV.getNode());
-    AddUsersToWorklist(RV.getNode());
+    // Push the new node and any users onto the worklist.  Omit this if the
+    // new node is the EntryToken (e.g. if a store managed to get optimized
+    // out), because re-visiting the EntryToken and its users will not uncover
+    // any additional opportunities, but there may be a large number of such
+    // users, potentially causing compile time explosion.
+    if (RV.getOpcode() != ISD::EntryToken) {
+      AddToWorklist(RV.getNode());
+      AddUsersToWorklist(RV.getNode());
+    }
 
     // Finally, if the node is now dead, remove it from the graph.  The node
     // may not be dead if the replacement process recursively simplified to


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