From 3df8534be19d69a9309f7806f13bd56711aa1516 Mon Sep 17 00:00:00 2001
From: "Duncan P. N. Exon Smith" <dexonsmith@apple.com>
Date: Fri, 25 Apr 2014 04:38:09 +0000
Subject: [PATCH] blockfreq: Store the header with the members

<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207182 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../llvm/Analysis/BlockFrequencyInfoImpl.h    | 24 ++++++++++++-------
 lib/Analysis/BlockFrequencyInfoImpl.cpp       |  4 ++--
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/include/llvm/Analysis/BlockFrequencyInfoImpl.h b/include/llvm/Analysis/BlockFrequencyInfoImpl.h
index 797ebb7c034..f9978cc1c47 100644
--- a/include/llvm/Analysis/BlockFrequencyInfoImpl.h
+++ b/include/llvm/Analysis/BlockFrequencyInfoImpl.h
@@ -16,6 +16,7 @@
 
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/PostOrderIterator.h"
+#include "llvm/ADT/iterator_range.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/Support/BlockFrequency.h"
 #include "llvm/Support/BranchProbability.h"
@@ -946,18 +947,25 @@ public:
     typedef SmallVector<std::pair<BlockNode, BlockMass>, 4> ExitMap;
     typedef SmallVector<BlockNode, 4> MemberList;
     LoopData *Parent;       ///< The parent loop.
-    BlockNode Header;       ///< Header.
     bool IsPackaged;        ///< Whether this has been packaged.
     ExitMap Exits;          ///< Successor edges (and weights).
-    MemberList Members;     ///< Members of the loop.
+    MemberList Nodes;       ///< Header and the members of the loop.
     BlockMass BackedgeMass; ///< Mass returned to loop header.
     BlockMass Mass;
     Float Scale;
 
     LoopData(LoopData *Parent, const BlockNode &Header)
-        : Parent(Parent), Header(Header), IsPackaged(false) {}
-    bool isHeader(const BlockNode &Node) const { return Node == Header; }
-    BlockNode getHeader() const { return Header; }
+        : Parent(Parent), IsPackaged(false), Nodes(1, Header) {}
+    bool isHeader(const BlockNode &Node) const { return Node == Nodes[0]; }
+    BlockNode getHeader() const { return Nodes[0]; }
+
+    MemberList::const_iterator members_begin() const {
+      return Nodes.begin() + 1;
+    }
+    MemberList::const_iterator members_end() const { return Nodes.end(); }
+    iterator_range<MemberList::const_iterator> members() const {
+      return make_range(members_begin(), members_end());
+    }
   };
 
   /// \brief Index of loop information.
@@ -1463,7 +1471,7 @@ template <class BT> void BlockFrequencyInfoImpl<BT>::initializeLoops() {
     if (Working[Index].isLoopHeader()) {
       LoopData *ContainingLoop = Working[Index].getContainingLoop();
       if (ContainingLoop)
-        ContainingLoop->Members.push_back(Index);
+        ContainingLoop->Nodes.push_back(Index);
       continue;
     }
 
@@ -1478,7 +1486,7 @@ template <class BT> void BlockFrequencyInfoImpl<BT>::initializeLoops() {
     assert(HeaderData.isLoopHeader());
 
     Working[Index].Loop = HeaderData.Loop;
-    HeaderData.Loop->Members.push_back(Index);
+    HeaderData.Loop->Nodes.push_back(Index);
     DEBUG(dbgs() << " - loop = " << getBlockName(Header)
                  << ": member = " << getBlockName(Index) << "\n");
   }
@@ -1499,7 +1507,7 @@ void BlockFrequencyInfoImpl<BT>::computeMassInLoop(LoopData &Loop) {
   Working[Loop.getHeader().Index].Mass = BlockMass::getFull();
   propagateMassToSuccessors(&Loop, Loop.getHeader());
 
-  for (const BlockNode &M : Loop.Members)
+  for (const BlockNode &M : Loop.members())
     propagateMassToSuccessors(&Loop, M);
 
   computeLoopScale(Loop);
diff --git a/lib/Analysis/BlockFrequencyInfoImpl.cpp b/lib/Analysis/BlockFrequencyInfoImpl.cpp
index 90090d7e8f1..761bda5aa9b 100644
--- a/lib/Analysis/BlockFrequencyInfoImpl.cpp
+++ b/lib/Analysis/BlockFrequencyInfoImpl.cpp
@@ -746,7 +746,7 @@ void BlockFrequencyInfoImplBase::packageLoop(LoopData &Loop) {
   DEBUG(dbgs() << "packaging-loop: " << getBlockName(Loop.getHeader()) << "\n");
   Loop.IsPackaged = true;
   DEBUG(for (const BlockNode &M
-             : Loop.Members) {
+             : Loop.members()) {
                dbgs() << " - node: " << getBlockName(M.Index) << "\n";
              });
 }
@@ -859,7 +859,7 @@ static void unwrapLoopPackage(BlockFrequencyInfoImplBase &BFI,
   // Propagate the head scale through the loop.  Since members are visited in
   // RPO, the head scale will be updated by the loop scale first, and then the
   // final head scale will be used for updated the rest of the members.
-  for (const BlockNode &M : LoopPackage.Members) {
+  for (const BlockNode &M : LoopPackage.members()) {
     const FrequencyData &HeadData = BFI.Freqs[Head.Index];
     FrequencyData &Freqs = BFI.Freqs[M.Index];
     Float NewFreq = Freqs.Floating * HeadData.Floating;
-- 
2.34.1