Avoid a Symbol -> Name -> Symbol conversion.

Before this we were producing a TargetExternalSymbol from a MCSymbol.
That meant extracting the symbol name and fetching the symbol again
down the pipeline.

This patch adds a DAG.getMCSymbol that lets the MCSymbol pass unchanged on the
DAG.

Doing so removes the need for MO_NOPREFIX and fixes the root cause of pr23900,
allowing r240130 to be committed again.

llvm-svn: 240300

1 files changed, 1 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h
index 4c74182014a..5403baef034 100644
--- a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h
+++ b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h
@@ -64,6 +64,7 @@ namespace llvm {
       if (isa<TargetIndexSDNode>(Node))    return true;
       if (isa<JumpTableSDNode>(Node))      return true;
       if (isa<ExternalSymbolSDNode>(Node)) return true;
+      if (isa<MCSymbolSDNode>(Node))       return true;
       if (isa<BlockAddressSDNode>(Node))   return true;
       if (Node->getOpcode() == ISD::EntryToken ||
           isa<MDNodeSDNode>(Node)) return true;