BBVectorize: Make the bookkeeping to support full cycle checking less expensive

By itself, this does not have much of an effect, but only because in the default
configuration the full cycle checks are used only for small problem sizes.
This is part of a general cleanup of uses of iteration over std::multimap
ranges only for the purpose of checking membership.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174856 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 25 insertions, 14 deletions

diff --git a/lib/Transforms/Vectorize/BBVectorize.cpp b/lib/Transforms/Vectorize/BBVectorize.cpp
index ec10b4207b..824494dcc7 100644
--- a/lib/Transforms/Vectorize/BBVectorize.cpp
+++ b/lib/Transforms/Vectorize/BBVectorize.cpp
@@ -288,7 +288,8 @@ namespace {
 
     bool pairsConflict(ValuePair P, ValuePair Q,
                  DenseSet<ValuePair> &PairableInstUsers,
-                 std::multimap<ValuePair, ValuePair> *PairableInstUserMap = 0);
+                 std::multimap<ValuePair, ValuePair> *PairableInstUserMap = 0,
+                 DenseSet<VPPair> *PairableInstUserPairSet = 0);
 
     bool pairWillFormCycle(ValuePair P,
                        std::multimap<ValuePair, ValuePair> &PairableInstUsers,
@@ -300,6 +301,7 @@ namespace {
                       std::multimap<ValuePair, ValuePair> &ConnectedPairs,
                       DenseSet<ValuePair> &PairableInstUsers,
                       std::multimap<ValuePair, ValuePair> &PairableInstUserMap,
+                      DenseSet<VPPair> &PairableInstUserPairSet,
                       DenseMap<Value *, Value *> &ChosenPairs,
                       DenseMap<ValuePair, size_t> &Tree,
                       DenseSet<ValuePair> &PrunedTree, ValuePair J,
@@ -323,6 +325,7 @@ namespace {
                       std::multimap<ValuePair, ValuePair> &ConnectedPairDeps,
                       DenseSet<ValuePair> &PairableInstUsers,
                       std::multimap<ValuePair, ValuePair> &PairableInstUserMap,
+                      DenseSet<VPPair> &PairableInstUserPairSet,
                       DenseMap<Value *, Value *> &ChosenPairs,
                       DenseSet<ValuePair> &BestTree, size_t &BestMaxDepth,
                       int &BestEffSize, VPIteratorPair ChoiceRange,
@@ -1401,7 +1404,8 @@ namespace {
   // two pairs cannot be simultaneously fused.
   bool BBVectorize::pairsConflict(ValuePair P, ValuePair Q,
                      DenseSet<ValuePair> &PairableInstUsers,
-                     std::multimap<ValuePair, ValuePair> *PairableInstUserMap) {
+                     std::multimap<ValuePair, ValuePair> *PairableInstUserMap,
+                     DenseSet<VPPair> *PairableInstUserPairSet) {
     // Two pairs are in conflict if they are mutual Users of eachother.
     bool QUsesP = PairableInstUsers.count(ValuePair(P.first,  Q.first))  ||
                   PairableInstUsers.count(ValuePair(P.first,  Q.second)) ||
@@ -1417,13 +1421,11 @@ namespace {
       // profiling and probably a different data structure (same is true of
       // most uses of std::multimap).
       if (PUsesQ) {
-        VPPIteratorPair QPairRange = PairableInstUserMap->equal_range(Q);
-        if (!isSecondInIteratorPair(P, QPairRange))
+        if (PairableInstUserPairSet->insert(VPPair(Q, P)).second)
           PairableInstUserMap->insert(VPPair(Q, P));
       }
       if (QUsesP) {
-        VPPIteratorPair PPairRange = PairableInstUserMap->equal_range(P);
-        if (!isSecondInIteratorPair(Q, PPairRange))
+        if (PairableInstUserPairSet->insert(VPPair(P, Q)).second)
           PairableInstUserMap->insert(VPPair(P, Q));
       }
     }
@@ -1534,6 +1536,7 @@ namespace {
                       std::multimap<ValuePair, ValuePair> &ConnectedPairs,
                       DenseSet<ValuePair> &PairableInstUsers,
                       std::multimap<ValuePair, ValuePair> &PairableInstUserMap,
+                      DenseSet<VPPair> &PairableInstUserPairSet,
                       DenseMap<Value *, Value *> &ChosenPairs,
                       DenseMap<ValuePair, size_t> &Tree,
                       DenseSet<ValuePair> &PrunedTree, ValuePair J,
@@ -1586,7 +1589,8 @@ namespace {
               C2->first.second == C->first.first ||
               C2->first.second == C->first.second ||
               pairsConflict(C2->first, C->first, PairableInstUsers,
-                            UseCycleCheck ? &PairableInstUserMap : 0)) {
+                            UseCycleCheck ? &PairableInstUserMap : 0,
+                            UseCycleCheck ? &PairableInstUserPairSet : 0)) {
             if (C2->second >= C->second) {
               CanAdd = false;
               break;
@@ -1606,7 +1610,8 @@ namespace {
               T->second == C->first.first ||
               T->second == C->first.second ||
               pairsConflict(*T, C->first, PairableInstUsers,
-                            UseCycleCheck ? &PairableInstUserMap : 0)) {
+                            UseCycleCheck ? &PairableInstUserMap : 0,
+                            UseCycleCheck ? &PairableInstUserPairSet : 0)) {
             CanAdd = false;
             break;
           }
@@ -1623,7 +1628,8 @@ namespace {
               C2->first.second == C->first.first ||
               C2->first.second == C->first.second ||
               pairsConflict(C2->first, C->first, PairableInstUsers,
-                            UseCycleCheck ? &PairableInstUserMap : 0)) {
+                            UseCycleCheck ? &PairableInstUserMap : 0,
+                            UseCycleCheck ? &PairableInstUserPairSet : 0)) {
             CanAdd = false;
             break;
           }
@@ -1638,7 +1644,8 @@ namespace {
               ChosenPairs.begin(), E2 = ChosenPairs.end();
              C2 != E2; ++C2) {
           if (pairsConflict(*C2, C->first, PairableInstUsers,
-                            UseCycleCheck ? &PairableInstUserMap : 0)) {
+                            UseCycleCheck ? &PairableInstUserMap : 0,
+                            UseCycleCheck ? &PairableInstUserPairSet : 0)) {
             CanAdd = false;
             break;
           }
@@ -1699,6 +1706,7 @@ namespace {
                       std::multimap<ValuePair, ValuePair> &ConnectedPairDeps,
                       DenseSet<ValuePair> &PairableInstUsers,
                       std::multimap<ValuePair, ValuePair> &PairableInstUserMap,
+                      DenseSet<VPPair> &PairableInstUserPairSet,
                       DenseMap<Value *, Value *> &ChosenPairs,
                       DenseSet<ValuePair> &BestTree, size_t &BestMaxDepth,
                       int &BestEffSize, VPIteratorPair ChoiceRange,
@@ -1714,7 +1722,8 @@ namespace {
       for (DenseMap<Value *, Value *>::iterator C = ChosenPairs.begin(),
            E = ChosenPairs.end(); C != E; ++C) {
         if (pairsConflict(*C, *J, PairableInstUsers,
-                          UseCycleCheck ? &PairableInstUserMap : 0)) {
+                          UseCycleCheck ? &PairableInstUserMap : 0,
+                          UseCycleCheck ? &PairableInstUserPairSet : 0)) {
           DoesConflict = true;
           break;
         }
@@ -1748,8 +1757,8 @@ namespace {
 
       DenseSet<ValuePair> PrunedTree;
       pruneTreeFor(CandidatePairs, PairableInsts, ConnectedPairs,
-                   PairableInstUsers, PairableInstUserMap, ChosenPairs, Tree,
-                   PrunedTree, *J, UseCycleCheck);
+                   PairableInstUsers, PairableInstUserMap, PairableInstUserPairSet,
+                   ChosenPairs, Tree, PrunedTree, *J, UseCycleCheck);
 
       int EffSize = 0;
       if (TTI) {
@@ -2075,6 +2084,7 @@ namespace {
     bool UseCycleCheck =
      CandidatePairs.size() <= Config.MaxCandPairsForCycleCheck;
     std::multimap<ValuePair, ValuePair> PairableInstUserMap;
+    DenseSet<VPPair> PairableInstUserPairSet;
     for (std::vector<Value *>::iterator I = PairableInsts.begin(),
          E = PairableInsts.end(); I != E; ++I) {
       // The number of possible pairings for this variable:
@@ -2090,7 +2100,8 @@ namespace {
       findBestTreeFor(CandidatePairs, CandidatePairCostSavings,
                       PairableInsts, FixedOrderPairs, PairConnectionTypes,
                       ConnectedPairs, ConnectedPairDeps,
-                      PairableInstUsers, PairableInstUserMap, ChosenPairs,
+                      PairableInstUsers, PairableInstUserMap,
+                      PairableInstUserPairSet, ChosenPairs,
                       BestTree, BestMaxDepth, BestEffSize, ChoiceRange,
                       UseCycleCheck);