From 10f28f26fd766db00cd2ea7d10fe75777046b0cb Mon Sep 17 00:00:00 2001
From: Chandler Carruth <chandlerc@gmail.com>
Date: Tue, 20 Jan 2015 01:37:09 +0000
Subject: [PATCH] [PM] Replace the Pass argument in MergeBasicBlockIntoOnlyPred
 with a DominatorTree argument as that is the analysis that it wants to
 update.

This removes the last non-loop utility function in Utils/ which accepts
a raw Pass argument.

llvm-svn: 226537
---
 llvm/include/llvm/Transforms/Utils/Local.h |  3 +--
 llvm/lib/CodeGen/CodeGenPrepare.cpp        |  4 ++--
 llvm/lib/Transforms/Utils/Local.cpp        | 14 +++++---------
 3 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/llvm/include/llvm/Transforms/Utils/Local.h b/llvm/include/llvm/Transforms/Utils/Local.h
index 14844117f44f..a383b0d34bc8 100644
--- a/llvm/include/llvm/Transforms/Utils/Local.h
+++ b/llvm/include/llvm/Transforms/Utils/Local.h
@@ -31,7 +31,6 @@ class DbgDeclareInst;
 class StoreInst;
 class LoadInst;
 class Value;
-class Pass;
 class PHINode;
 class AllocaInst;
 class AssumptionCache;
@@ -115,7 +114,7 @@ void RemovePredecessorAndSimplify(BasicBlock *BB, BasicBlock *Pred,
 /// between them, moving the instructions in the predecessor into BB.  This
 /// deletes the predecessor block.
 ///
-void MergeBasicBlockIntoOnlyPred(BasicBlock *BB, Pass *P = nullptr);
+void MergeBasicBlockIntoOnlyPred(BasicBlock *BB, DominatorTree *DT = nullptr);
 
 /// TryToSimplifyUncondBranchFromEmptyBlock - BB is known to contain an
 /// unconditional branch, and contains no instructions other than PHI nodes,
diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index ce917064e529..c01fc2e22775 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -342,7 +342,7 @@ bool CodeGenPrepare::EliminateFallThrough(Function &F) {
       // Remember if SinglePred was the entry block of the function.
       // If so, we will need to move BB back to the entry position.
       bool isEntry = SinglePred == &SinglePred->getParent()->getEntryBlock();
-      MergeBasicBlockIntoOnlyPred(BB, this);
+      MergeBasicBlockIntoOnlyPred(BB, DT);
 
       if (isEntry && BB != &BB->getParent()->getEntryBlock())
         BB->moveBefore(&BB->getParent()->getEntryBlock());
@@ -482,7 +482,7 @@ void CodeGenPrepare::EliminateMostlyEmptyBlock(BasicBlock *BB) {
       // Remember if SinglePred was the entry block of the function.  If so, we
       // will need to move BB back to the entry position.
       bool isEntry = SinglePred == &SinglePred->getParent()->getEntryBlock();
-      MergeBasicBlockIntoOnlyPred(DestBB, this);
+      MergeBasicBlockIntoOnlyPred(DestBB, DT);
 
       if (isEntry && BB != &BB->getParent()->getEntryBlock())
         BB->moveBefore(&BB->getParent()->getEntryBlock());
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 08a4b3f3b737..a6bdc7f7b839 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -489,7 +489,7 @@ void llvm::RemovePredecessorAndSimplify(BasicBlock *BB, BasicBlock *Pred,
 /// between them, moving the instructions in the predecessor into DestBB and
 /// deleting the predecessor block.
 ///
-void llvm::MergeBasicBlockIntoOnlyPred(BasicBlock *DestBB, Pass *P) {
+void llvm::MergeBasicBlockIntoOnlyPred(BasicBlock *DestBB, DominatorTree *DT) {
   // If BB has single-entry PHI nodes, fold them.
   while (PHINode *PN = dyn_cast<PHINode>(DestBB->begin())) {
     Value *NewVal = PN->getIncomingValue(0);
@@ -525,14 +525,10 @@ void llvm::MergeBasicBlockIntoOnlyPred(BasicBlock *DestBB, Pass *P) {
   if (PredBB == &DestBB->getParent()->getEntryBlock())
     DestBB->moveAfter(PredBB);
 
-  if (P) {
-    if (DominatorTreeWrapperPass *DTWP =
-            P->getAnalysisIfAvailable<DominatorTreeWrapperPass>()) {
-      DominatorTree &DT = DTWP->getDomTree();
-      BasicBlock *PredBBIDom = DT.getNode(PredBB)->getIDom()->getBlock();
-      DT.changeImmediateDominator(DestBB, PredBBIDom);
-      DT.eraseNode(PredBB);
-    }
+  if (DT) {
+    BasicBlock *PredBBIDom = DT->getNode(PredBB)->getIDom()->getBlock();
+    DT->changeImmediateDominator(DestBB, PredBBIDom);
+    DT->eraseNode(PredBB);
   }
   // Nuke BB.
   PredBB->eraseFromParent();