[SelectionDAG] Add getTokenFactor, which splits nodes with > 64k operands.

This functionality is required at multiple places which potentially
create large operand lists, like SelectionDAGBuilder or DAGCombiner.

Differential Revision: https://reviews.llvm.org/D56739

llvm-svn: 351552

1 files changed, 1 insertions, 13 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 9f09f25f2ff..69cae0fbb90 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1032,19 +1032,7 @@ SDValue SelectionDAGBuilder::getRoot() {
   }
 
   // Otherwise, we have to make a token factor node.
-  // If we have >= 2^16 loads then split across multiple token factors as
-  // there's a 64k limit on the number of SDNode operands.
-  SDValue Root;
-  size_t Limit = SDNode::getMaxNumOperands();
-  while (PendingLoads.size() > Limit) {
-    unsigned SliceIdx = PendingLoads.size() - Limit;
-    auto ExtractedTFs = ArrayRef<SDValue>(PendingLoads).slice(SliceIdx, Limit);
-    SDValue NewTF =
-        DAG.getNode(ISD::TokenFactor, getCurSDLoc(), MVT::Other, ExtractedTFs);
-    PendingLoads.erase(PendingLoads.begin() + SliceIdx, PendingLoads.end());
-    PendingLoads.emplace_back(NewTF);
-  }
-  Root = DAG.getNode(ISD::TokenFactor, getCurSDLoc(), MVT::Other, PendingLoads);
+  SDValue Root = DAG.getTokenFactor(getCurSDLoc(), PendingLoads);
   PendingLoads.clear();
   DAG.setRoot(Root);
   return Root;