From 0e8f85f87e9388179f9708e8a9898e48632f1bab Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Sun, 5 Aug 2007 00:15:57 +0000
Subject: [PATCH] Switch some std::sets to SmallPtrSet.  This speeds up domtree
 by 10% and postdomtree by 17%

llvm-svn: 40829
---
 llvm/lib/Analysis/PostDominators.cpp | 6 +++---
 llvm/lib/VMCore/Dominators.cpp       | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/llvm/lib/Analysis/PostDominators.cpp b/llvm/lib/Analysis/PostDominators.cpp
index 244f8cdff525..d2892de8ed24 100644
--- a/llvm/lib/Analysis/PostDominators.cpp
+++ b/llvm/lib/Analysis/PostDominators.cpp
@@ -29,7 +29,7 @@ F("postdomtree", "Post-Dominator Tree Construction", true);
 
 unsigned PostDominatorTree::DFSPass(BasicBlock *V, unsigned N) {
   std::vector<BasicBlock *> workStack;
-  std::set<BasicBlock *> visited;
+  SmallPtrSet<BasicBlock *, 32> Visited;
   workStack.push_back(V);
 
   do {
@@ -37,7 +37,7 @@ unsigned PostDominatorTree::DFSPass(BasicBlock *V, unsigned N) {
     InfoRec &CurVInfo = Info[currentBB];
 
     // Visit each block only once.
-    if (visited.insert(currentBB).second) {
+    if (Visited.insert(currentBB)) {
       CurVInfo.Semi = ++N;
       CurVInfo.Label = currentBB;
       
@@ -55,7 +55,7 @@ unsigned PostDominatorTree::DFSPass(BasicBlock *V, unsigned N) {
       InfoRec &SuccVInfo = Info[*PI];
       if (SuccVInfo.Semi == 0) {
         SuccVInfo.Parent = currentBB;
-        if (!visited.count(*PI)) {
+        if (!Visited.count(*PI)) {
           workStack.push_back(*PI);   
           visitChild = true;
         }
diff --git a/llvm/lib/VMCore/Dominators.cpp b/llvm/lib/VMCore/Dominators.cpp
index 6231eb8e469d..7d0fbaa29aa5 100644
--- a/llvm/lib/VMCore/Dominators.cpp
+++ b/llvm/lib/VMCore/Dominators.cpp
@@ -211,7 +211,7 @@ unsigned DominatorTree::DFSPass(BasicBlock *V, unsigned N) {
 void DominatorTree::Compress(BasicBlock *VIn) {
 
   std::vector<BasicBlock *> Work;
-  std::set<BasicBlock *> Visited;
+  SmallPtrSet<BasicBlock *, 32> Visited;
   BasicBlock *VInAncestor = Info[VIn].Ancestor;
   InfoRec &VInVAInfo = Info[VInAncestor];
 
@@ -225,9 +225,9 @@ void DominatorTree::Compress(BasicBlock *VIn) {
     InfoRec &VAInfo = Info[VAncestor];
 
     // Process Ancestor first
-    if (Visited.count(VAncestor) == 0 && VAInfo.Ancestor != 0) {
+    if (Visited.insert(VAncestor) &&
+        VAInfo.Ancestor != 0) {
       Work.push_back(VAncestor);
-      Visited.insert(VAncestor);
       continue;
     } 
     Work.pop_back();