"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, 4 insertions, 2 deletions

diff --git a/include/llvm/CodeGen/MachineBasicBlock.h b/include/llvm/CodeGen/MachineBasicBlock.h
index 54ac47008f..5a9f3991f2 100644
--- a/include/llvm/CodeGen/MachineBasicBlock.h
+++ b/include/llvm/CodeGen/MachineBasicBlock.h
@@ -26,14 +26,16 @@ class MachineFunction;
 template <>
 struct ilist_traits<MachineInstr> : public ilist_default_traits<MachineInstr> {
 private:
-  mutable MachineInstr Sentinel;
+  mutable ilist_node<MachineInstr> Sentinel;
 
   // this is only set by the MachineBasicBlock owning the LiveList
   friend class MachineBasicBlock;
   MachineBasicBlock* Parent;
 
 public:
-  MachineInstr *createSentinel() const { return &Sentinel; }
+  MachineInstr *createSentinel() const {
+    return static_cast<MachineInstr*>(&Sentinel);
+  }
   void destroySentinel(MachineInstr *) const {}
 
   void addNodeToList(MachineInstr* N);