From b7f66977be8f5248b1638b796d8abff4b24e7915 Mon Sep 17 00:00:00 2001
From: Chandler Carruth <chandlerc@gmail.com>
Date: Sun, 18 Jan 2015 01:45:07 +0000
Subject: [PATCH] [PM] Lift the actual analyses used into the inferface rather
 than accepting a Pass and querying it for analyses.

This is necessary to allow the utilities to work both with the old and
new pass managers, and I also think this makes the interface much more
clear and helps the reader know what analyses the utility can actually
handle. I plan to repeat this process iteratively to clean up all the
pass utilities.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226386 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Transforms/Utils/BasicBlockUtils.h |  4 +++-
 lib/Transforms/Utils/BasicBlockUtils.cpp        | 17 +++++++----------
 2 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/include/llvm/Transforms/Utils/BasicBlockUtils.h b/include/llvm/Transforms/Utils/BasicBlockUtils.h
index 19acf5b2db8..858323d051d 100644
--- a/include/llvm/Transforms/Utils/BasicBlockUtils.h
+++ b/include/llvm/Transforms/Utils/BasicBlockUtils.h
@@ -23,6 +23,7 @@
 namespace llvm {
 
 class AliasAnalysis;
+class MemoryDependenceAnalysis;
 class DominatorTree;
 class Instruction;
 class MDNode;
@@ -39,7 +40,8 @@ void DeleteDeadBlock(BasicBlock *BB);
 /// any single-entry PHI nodes in it, fold them away.  This handles the case
 /// when all entries to the PHI nodes in a block are guaranteed equal, such as
 /// when the block has exactly one predecessor.
-void FoldSingleEntryPHINodes(BasicBlock *BB, Pass *P = nullptr);
+void FoldSingleEntryPHINodes(BasicBlock *BB, AliasAnalysis *AA = nullptr,
+                             MemoryDependenceAnalysis *MemDep = nullptr);
 
 /// DeleteDeadPHIs - Examine each PHI in the given block and delete it if it
 /// is dead. Also recursively delete any operands that become dead as
diff --git a/lib/Transforms/Utils/BasicBlockUtils.cpp b/lib/Transforms/Utils/BasicBlockUtils.cpp
index 867e4337cfc..29b5d2bb903 100644
--- a/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ b/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -65,16 +65,10 @@ void llvm::DeleteDeadBlock(BasicBlock *BB) {
 /// any single-entry PHI nodes in it, fold them away.  This handles the case
 /// when all entries to the PHI nodes in a block are guaranteed equal, such as
 /// when the block has exactly one predecessor.
-void llvm::FoldSingleEntryPHINodes(BasicBlock *BB, Pass *P) {
+void llvm::FoldSingleEntryPHINodes(BasicBlock *BB, AliasAnalysis *AA,
+                                   MemoryDependenceAnalysis *MemDep) {
   if (!isa<PHINode>(BB->begin())) return;
 
-  AliasAnalysis *AA = nullptr;
-  MemoryDependenceAnalysis *MemDep = nullptr;
-  if (P) {
-    AA = P->getAnalysisIfAvailable<AliasAnalysis>();
-    MemDep = P->getAnalysisIfAvailable<MemoryDependenceAnalysis>();
-  }
-
   while (PHINode *PN = dyn_cast<PHINode>(BB->begin())) {
     if (PN->getIncomingValue(0) != PN)
       PN->replaceAllUsesWith(PN->getIncomingValue(0));
@@ -148,8 +142,11 @@ bool llvm::MergeBlockIntoPredecessor(BasicBlock *BB, Pass *P) {
   }
 
   // Begin by getting rid of unneeded PHIs.
-  if (isa<PHINode>(BB->front()))
-    FoldSingleEntryPHINodes(BB, P);
+  if (isa<PHINode>(BB->front())) {
+    auto *AA = P ? P->getAnalysisIfAvailable<AliasAnalysis>() : nullptr;
+    auto *MemDep = P ? P->getAnalysisIfAvailable<MemoryDependenceAnalysis>() : nullptr;
+    FoldSingleEntryPHINodes(BB, AA, MemDep);
+  }
 
   // Delete the unconditional branch from the predecessor...
   PredBB->getInstList().pop_back();
-- 
2.34.1