From: Sanjoy Das <sanjoy@playingwithpointers.com>
Date: Sun, 25 Sep 2016 23:11:55 +0000 (+0000)
Subject: [SCEV] Remove incidental data structure; NFC
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3b4332c09011b099ca611b6a4f364232d2a4523f;p=llvm

[SCEV] Remove incidental data structure; NFC

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282363 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/Analysis/ScalarEvolution.h b/include/llvm/Analysis/ScalarEvolution.h
index 0194a3d8029..0fe0d0ba3e5 100644
--- a/include/llvm/Analysis/ScalarEvolution.h
+++ b/include/llvm/Analysis/ScalarEvolution.h
@@ -691,22 +691,7 @@ private:
     SmallVector<ExitNotTakenInfo, 4> Exits;
   };
 
-  /// A struct containing the information attached to a backedge.
-  struct EdgeInfo {
-    EdgeInfo(BasicBlock *Block, const SCEV *Taken, SCEVUnionPredicate &P)
-        : ExitBlock(Block), Taken(Taken), Pred(std::move(P)) {}
-
-    /// The exit basic block.
-    BasicBlock *ExitBlock;
-
-    /// The (exact) number of time we take the edge back.
-    const SCEV *Taken;
-
-    /// The SCEV predicated associated with Taken. If Pred doesn't evaluate
-    /// to true, the information in Taken is not valid (or equivalent with
-    /// a CouldNotCompute.
-    SCEVUnionPredicate Pred;
-  };
+  typedef std::pair<BasicBlock *, ExitLimit> EdgeExitInfo;
 
   /// Information about the backedge-taken count of a loop. This currently
   /// includes an exact count and a maximum count.
@@ -725,7 +710,7 @@ private:
     BackedgeTakenInfo() : Max(nullptr) {}
 
     /// Initialize BackedgeTakenInfo from a list of exact exit counts.
-    BackedgeTakenInfo(SmallVectorImpl<EdgeInfo> &ExitCounts, bool Complete,
+    BackedgeTakenInfo(ArrayRef<EdgeExitInfo> ExitCounts, bool Complete,
                       const SCEV *MaxCount);
 
     /// Test whether this BackedgeTakenInfo contains any computed information,
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index e97e6684290..84dca06033b 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -5669,26 +5669,30 @@ bool ScalarEvolution::BackedgeTakenInfo::hasOperand(const SCEV *S,
 /// Allocate memory for BackedgeTakenInfo and copy the not-taken count of each
 /// computable exit into a persistent ExitNotTakenInfo array.
 ScalarEvolution::BackedgeTakenInfo::BackedgeTakenInfo(
-    SmallVectorImpl<EdgeInfo> &ExitCounts, bool Complete, const SCEV *MaxCount)
+    ArrayRef<ScalarEvolution::EdgeExitInfo> ExitCounts, bool Complete,
+    const SCEV *MaxCount)
     : Max(MaxCount) {
 
   if (!Complete)
     ExitNotTaken.setIncomplete();
 
   unsigned NumExits = ExitCounts.size();
-  if (NumExits == 0) return;
+  if (NumExits == 0)
+    return;
 
-  ExitNotTaken.ExitingBlock = ExitCounts[0].ExitBlock;
-  ExitNotTaken.ExactNotTaken = ExitCounts[0].Taken;
+  ExitNotTaken.ExitingBlock = ExitCounts[0].first;
+  ExitNotTaken.ExactNotTaken = ExitCounts[0].second.Exact;
 
   // Determine the number of ExitNotTakenExtras structures that we need.
   unsigned ExtraInfoSize = 0;
-  if (NumExits > 1)
+  if (NumExits > 1) {
+    auto HasNonTrivialPredicate =
+        [](const ScalarEvolution::EdgeExitInfo &Entry) {
+          return !Entry.second.Pred.isAlwaysTrue();
+        };
     ExtraInfoSize = 1 + std::count_if(std::next(ExitCounts.begin()),
-                                      ExitCounts.end(), [](EdgeInfo &Entry) {
-                                        return !Entry.Pred.isAlwaysTrue();
-                                      });
-  else if (!ExitCounts[0].Pred.isAlwaysTrue())
+                                      ExitCounts.end(), HasNonTrivialPredicate);
+  } else if (!ExitCounts[0].second.Pred.isAlwaysTrue())
     ExtraInfoSize = 1;
 
   ExitNotTakenExtras *ENT = nullptr;
@@ -5698,7 +5702,7 @@ ScalarEvolution::BackedgeTakenInfo::BackedgeTakenInfo(
   if (ExtraInfoSize > 0) {
     ENT = new ExitNotTakenExtras[ExtraInfoSize];
     ExitNotTaken.ExtraInfo = &ENT[0];
-    *ExitNotTaken.getPred() = std::move(ExitCounts[0].Pred);
+    *ExitNotTaken.getPred() = std::move(ExitCounts[0].second.Pred);
   }
 
   if (NumExits == 1)
@@ -5711,12 +5715,12 @@ ScalarEvolution::BackedgeTakenInfo::BackedgeTakenInfo(
   // Handle the rare case of multiple computable exits.
   for (unsigned i = 1, PredPos = 1; i < NumExits; ++i) {
     ExitNotTakenExtras *Ptr = nullptr;
-    if (!ExitCounts[i].Pred.isAlwaysTrue()) {
+    if (!ExitCounts[i].second.Pred.isAlwaysTrue()) {
       Ptr = &ENT[PredPos++];
-      Ptr->Pred = std::move(ExitCounts[i].Pred);
+      Ptr->Pred = std::move(ExitCounts[i].second.Pred);
     }
 
-    Exits.emplace_back(ExitCounts[i].ExitBlock, ExitCounts[i].Taken, Ptr);
+    Exits.emplace_back(ExitCounts[i].first, ExitCounts[i].second.Exact, Ptr);
   }
 }
 
@@ -5734,7 +5738,7 @@ ScalarEvolution::computeBackedgeTakenCount(const Loop *L,
   SmallVector<BasicBlock *, 8> ExitingBlocks;
   L->getExitingBlocks(ExitingBlocks);
 
-  SmallVector<EdgeInfo, 4> ExitCounts;
+  SmallVector<ScalarEvolution::EdgeExitInfo, 4> ExitCounts;
   bool CouldComputeBECount = true;
   BasicBlock *Latch = L->getLoopLatch(); // may be NULL.
   const SCEV *MustExitMaxBECount = nullptr;
@@ -5757,7 +5761,7 @@ ScalarEvolution::computeBackedgeTakenCount(const Loop *L,
       // we won't be able to compute an exact value for the loop.
       CouldComputeBECount = false;
     else
-      ExitCounts.emplace_back(EdgeInfo(ExitBB, EL.Exact, EL.Pred));
+      ExitCounts.emplace_back(ExitBB, EL);
 
     // 2. Derive the loop's MaxBECount from each exit's max number of
     // non-exiting iterations. Partition the loop exits into two kinds: