"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

diff --git a/include/llvm/CodeGen/MachineBasicBlock.h b/include/llvm/CodeGen/MachineBasicBlock.h
index 54ac47008f231acd9a07ea296a6a1ddc11a24b27..5a9f3991f2c13f0ccba582ae7b87fe4edcbfe804 100644 (file)
--- 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);

diff --git a/include/llvm/CodeGen/MachineFunction.h b/include/llvm/CodeGen/MachineFunction.h
index 689e4357b1d7819b3894946e12e466b84c6a6c95..1371f1d0cdf797014b52bba63a301e47ee54ec43 100644 (file)
--- a/include/llvm/CodeGen/MachineFunction.h
+++ b/include/llvm/CodeGen/MachineFunction.h
@@ -37,9 +37,11 @@ class TargetMachine;
 template <>
 struct ilist_traits<MachineBasicBlock>
     : public ilist_default_traits<MachineBasicBlock> {
-  mutable MachineBasicBlock Sentinel;
+  mutable ilist_node<MachineBasicBlock> Sentinel;
 public:
-  MachineBasicBlock *createSentinel() const { return &Sentinel; }
+  MachineBasicBlock *createSentinel() const {
+    return static_cast<MachineBasicBlock*>(&Sentinel);
+  }
   void destroySentinel(MachineBasicBlock *) const {}
 
   void addNodeToList(MachineBasicBlock* MBB);

diff --git a/include/llvm/CodeGen/SelectionDAG.h b/include/llvm/CodeGen/SelectionDAG.h
index 9ecba590dd417dae69f9096d06eaa724c41e0834..fe89fe0546018ad9845b56abca68b4f524761c98 100644 (file)
--- 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 *) {}