When we legalize target nodes, do not use getNode to create a new node,

use UpdateNodeOperands to just update the operands!  This is important because
getNode will allocate a new node if the node returns a flag and this breaks
assumptions in the legalizer that you can legalize some things multiple times
and get exactly the same results.

This latent bug was exposed by my ppc patch last night, and this fixes
gsm/toast.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28348 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 13 deletions

diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 3799f7cc05..3fbfbf927a 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -529,19 +529,10 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
       // If this is a target node, legalize it by legalizing the operands then
       // passing it through.
       std::vector<SDOperand> Ops;
-      bool Changed = false;
-      for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
+      for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i)
         Ops.push_back(LegalizeOp(Node->getOperand(i)));
-        Changed = Changed || Node->getOperand(i) != Ops.back();
-      }
-      if (Changed)
-        if (Node->getNumValues() == 1)
-          Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Ops);
-        else {
-          std::vector<MVT::ValueType> VTs(Node->value_begin(),
-                                          Node->value_end());
-          Result = DAG.getNode(Node->getOpcode(), VTs, Ops);
-        }
+
+      Result = DAG.UpdateNodeOperands(Result.getValue(0), Ops);
 
       for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
         AddLegalizedOperand(Op.getValue(i), Result.getValue(i));
@@ -1058,7 +1049,7 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
 
     // Merge in the last call, to ensure that this call start after the last
     // call ended.
-    if (LastCALLSEQ_END.getOpcode() != ISD::EntryNode) {
+    if (LastCALLSEQ_END.getOpcode() != ISD::EntryToken) {
       Tmp1 = DAG.getNode(ISD::TokenFactor, MVT::Other, Tmp1, LastCALLSEQ_END);
       Tmp1 = LegalizeOp(Tmp1);
     }