From a36f46363f2e1205c17ff92b63412ea26ac65fb3 Mon Sep 17 00:00:00 2001
From: Daniel Berlin <dberlin@dberlin.org>
Date: Fri, 19 Aug 2016 22:06:23 +0000
Subject: [PATCH] Convert some depth first traversals to depth_first

llvm-svn: 279331
---
 llvm/lib/Transforms/Scalar/NaryReassociate.cpp            | 10 +++++-----
 llvm/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp | 11 +++--------
 llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp |  6 ++----
 3 files changed, 10 insertions(+), 17 deletions(-)

diff --git a/llvm/lib/Transforms/Scalar/NaryReassociate.cpp b/llvm/lib/Transforms/Scalar/NaryReassociate.cpp
index 5bde45f..e2081f7 100644
--- a/llvm/lib/Transforms/Scalar/NaryReassociate.cpp
+++ b/llvm/lib/Transforms/Scalar/NaryReassociate.cpp
@@ -207,11 +207,11 @@ static bool isPotentiallyNaryReassociable(Instruction *I) {
 bool NaryReassociatePass::doOneIteration(Function &F) {
   bool Changed = false;
   SeenExprs.clear();
-  // Process the basic blocks in pre-order of the dominator tree. This order
-  // ensures that all bases of a candidate are in Candidates when we process it.
-  for (auto Node = GraphTraits<DominatorTree *>::nodes_begin(DT);
-       Node != GraphTraits<DominatorTree *>::nodes_end(DT); ++Node) {
-    BasicBlock *BB = (*Node)->getBlock();
+  // Process the basic blocks in a depth first traversal of the dominator
+  // tree. This order ensures that all bases of a candidate are in Candidates
+  // when we process it.
+  for (const auto Node : depth_first(DT)) {
+    BasicBlock *BB = Node->getBlock();
     for (auto I = BB->begin(); I != BB->end(); ++I) {
       if (SE->isSCEVable(I->getType()) && isPotentiallyNaryReassociable(&*I)) {
         const SCEV *OldSCEV = SE->getSCEV(&*I);
diff --git a/llvm/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp b/llvm/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp
index e0180fb..961a3c1 100644
--- a/llvm/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp
+++ b/llvm/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp
@@ -1150,14 +1150,9 @@ bool SeparateConstOffsetFromGEP::reuniteExts(Instruction *I) {
 bool SeparateConstOffsetFromGEP::reuniteExts(Function &F) {
   bool Changed = false;
   DominatingExprs.clear();
-  for (auto Node = GraphTraits<DominatorTree *>::nodes_begin(DT);
-       Node != GraphTraits<DominatorTree *>::nodes_end(DT); ++Node) {
-    BasicBlock *BB = (*Node)->getBlock();
-    for (auto I = BB->begin(); I != BB->end(); ) {
-      Instruction *Cur = &*I++;
-      Changed |= reuniteExts(Cur);
-    }
-  }
+  for (const auto Node : depth_first(DT))
+    for (auto &I : *(Node->getBlock()))
+      Changed |= reuniteExts(&I);
   return Changed;
 }
 
diff --git a/llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp
index a4da5fe..a914517 100644
--- a/llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp
@@ -674,11 +674,9 @@ bool StraightLineStrengthReduce::runOnFunction(Function &F) {
   SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
   // Traverse the dominator tree in the depth-first order. This order makes sure
   // all bases of a candidate are in Candidates when we process it.
-  for (auto node = GraphTraits<DominatorTree *>::nodes_begin(DT);
-       node != GraphTraits<DominatorTree *>::nodes_end(DT); ++node) {
-    for (auto &I : *(*node)->getBlock())
+  for (const auto Node : depth_first(DT))
+    for (auto &I : *(Node->getBlock()))
       allocateCandidatesAndFindBasis(&I);
-  }
 
   // Rewrite candidates in the reverse depth-first order. This order makes sure
   // a candidate being rewritten is not a basis for any other candidate.
-- 
2.7.4