Replace std::vector -> SmallVector in BBVectorize

For now, this uses 8 on-stack elements. I'll need to do some profiling
to see if this is the best number.

Pointed out by Jakob in post-commit review.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167966 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Vectorize/BBVectorize.cpp b/lib/Transforms/Vectorize/BBVectorize.cpp
index e880acfa873742f25f0d0bb6f6e47313b053aebb..dacbc7f24257e95f48df3991bb64c8ac9a55d75d 100644 (file)
--- a/lib/Transforms/Vectorize/BBVectorize.cpp
+++ b/lib/Transforms/Vectorize/BBVectorize.cpp
@@ -1485,7 +1485,7 @@ namespace {
       PrunedTree.insert(QTop.first);
 
       // Visit each child, pruning as necessary...
-      std::vector<ValuePairWithDepth> BestChildren;
+      SmallVector<ValuePairWithDepth, 8> BestChildren;
       VPPIteratorPair QTopRange = ConnectedPairs.equal_range(QTop.first);
       for (std::multimap<ValuePair, ValuePair>::iterator K = QTopRange.first;
            K != QTopRange.second; ++K) {
@@ -1517,7 +1517,7 @@ namespace {
         DenseSet<ValuePair> CurrentPairs;
 
         bool CanAdd = true;
-        for (std::vector<ValuePairWithDepth>::iterator C2
+        for (SmallVector<ValuePairWithDepth, 8>::iterator C2
               = BestChildren.begin(), E2 = BestChildren.end();
              C2 != E2; ++C2) {
           if (C2->first.first == C->first.first ||
@@ -1602,7 +1602,7 @@ namespace {
         // to an already-selected child. Check for this here, and if a
         // conflict is found, then remove the previously-selected child
         // before adding this one in its place.
-        for (std::vector<ValuePairWithDepth>::iterator C2
+        for (SmallVector<ValuePairWithDepth, 8>::iterator C2
               = BestChildren.begin(); C2 != BestChildren.end();) {
           if (C2->first.first == C->first.first ||
               C2->first.first == C->first.second ||
@@ -1617,7 +1617,7 @@ namespace {
         BestChildren.push_back(ValuePairWithDepth(C->first, C->second));
       }
 
-      for (std::vector<ValuePairWithDepth>::iterator C
+      for (SmallVector<ValuePairWithDepth, 8>::iterator C
             = BestChildren.begin(), E2 = BestChildren.end();
            C != E2; ++C) {
         size_t DepthF = getDepthFactor(C->first.first);