"Ghostify" embedded sentinels. This is a real win in all cases

because less bytes are allocated and subobject construction is gone.
For reference how it works, see BasicBlock.h.
Btw. it is very assuring to see that somebody has invented
this ilist-embedded sentinel technique before me :-)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66026 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 5 deletions

diff --git a/include/llvm/CodeGen/SelectionDAG.h b/include/llvm/CodeGen/SelectionDAG.h
index 9ecba590dd..fe89fe0546 100644
--- a/include/llvm/CodeGen/SelectionDAG.h
+++ b/include/llvm/CodeGen/SelectionDAG.h
@@ -39,13 +39,10 @@ class FunctionLoweringInfo;
 
 template<> struct ilist_traits<SDNode> : public ilist_default_traits<SDNode> {
 private:
-  mutable SDNode Sentinel;
+  mutable ilist_node<SDNode> Sentinel;
 public:
-  ilist_traits() : Sentinel(ISD::DELETED_NODE, DebugLoc::getUnknownLoc(),
-                            SDVTList()) {}
-
   SDNode *createSentinel() const {
-    return &Sentinel;
+    return static_cast<SDNode*>(&Sentinel);
   }
   static void destroySentinel(SDNode *) {}