From 8d89e7bdbcea38fe2ab3c85d91359712cd45714b Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Tue, 9 May 2006 04:13:41 +0000
Subject: [PATCH] Patch to make some xforms preserve each other.  Patch
 contributed by Domagoj Babic!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28181 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Utils/LowerAllocations.cpp       |  7 +++++++
 lib/Transforms/Utils/LowerSelect.cpp            |  7 ++++++-
 lib/Transforms/Utils/LowerSwitch.cpp            | 11 ++++++++++-
 lib/Transforms/Utils/Mem2Reg.cpp                |  5 +++++
 lib/Transforms/Utils/UnifyFunctionExitNodes.cpp |  4 ++++
 5 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/lib/Transforms/Utils/LowerAllocations.cpp b/lib/Transforms/Utils/LowerAllocations.cpp
index 0a6dc09147e..f6e70e11f5f 100644
--- a/lib/Transforms/Utils/LowerAllocations.cpp
+++ b/lib/Transforms/Utils/LowerAllocations.cpp
@@ -13,6 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Utils/UnifyFunctionExitNodes.h"
 #include "llvm/Module.h"
 #include "llvm/DerivedTypes.h"
 #include "llvm/Instructions.h"
@@ -39,6 +40,12 @@ namespace {
     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
       AU.addRequired<TargetData>();
       AU.setPreservesCFG();
+
+      // This is a cluster of orthogonal Transforms:
+      AU.addPreserved<UnifyFunctionExitNodes>();
+      AU.addPreservedID(PromoteMemoryToRegisterID);
+      AU.addPreservedID(LowerSelectID);
+      AU.addPreservedID(LowerSwitchID);
     }
 
     /// doPassInitialization - For the lower allocations pass, this ensures that
diff --git a/lib/Transforms/Utils/LowerSelect.cpp b/lib/Transforms/Utils/LowerSelect.cpp
index 6a24c294cfd..27dd4307285 100644
--- a/lib/Transforms/Utils/LowerSelect.cpp
+++ b/lib/Transforms/Utils/LowerSelect.cpp
@@ -19,6 +19,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Utils/UnifyFunctionExitNodes.h"
 #include "llvm/Function.h"
 #include "llvm/Instructions.h"
 #include "llvm/Pass.h"
@@ -37,7 +38,11 @@ namespace {
     LowerSelect(bool onlyfp = false) : OnlyFP(onlyfp) {}
 
     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
-      // Doesn't really preserve anything.  It can certainly destroy the CFG.
+      // This certainly destroys the CFG.
+      // This is a cluster of orthogonal Transforms:
+      AU.addPreserved<UnifyFunctionExitNodes>();
+      AU.addPreservedID(PromoteMemoryToRegisterID);
+      AU.addPreservedID(LowerSwitchID);
     }
 
     bool runOnFunction(Function &F);
diff --git a/lib/Transforms/Utils/LowerSwitch.cpp b/lib/Transforms/Utils/LowerSwitch.cpp
index ebad6c36dbc..14d3027b918 100644
--- a/lib/Transforms/Utils/LowerSwitch.cpp
+++ b/lib/Transforms/Utils/LowerSwitch.cpp
@@ -14,6 +14,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Utils/UnifyFunctionExitNodes.h"
 #include "llvm/Constants.h"
 #include "llvm/Function.h"
 #include "llvm/Instructions.h"
@@ -32,7 +33,15 @@ namespace {
   /// modifies the CFG!
   class LowerSwitch : public FunctionPass {
   public:
-    bool runOnFunction(Function &F);
+    virtual bool runOnFunction(Function &F);
+
+    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+      // This is a cluster of orthogonal Transforms
+      AU.addPreserved<UnifyFunctionExitNodes>();
+      AU.addPreservedID(PromoteMemoryToRegisterID);
+      AU.addPreservedID(LowerSelectID);
+    }
+
     typedef std::pair<Constant*, BasicBlock*> Case;
     typedef std::vector<Case>::iterator       CaseItr;
   private:
diff --git a/lib/Transforms/Utils/Mem2Reg.cpp b/lib/Transforms/Utils/Mem2Reg.cpp
index c15d10c824e..9ca2c8300da 100644
--- a/lib/Transforms/Utils/Mem2Reg.cpp
+++ b/lib/Transforms/Utils/Mem2Reg.cpp
@@ -14,6 +14,7 @@
 
 #include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/Utils/PromoteMemToReg.h"
+#include "llvm/Transforms/Utils/UnifyFunctionExitNodes.h"
 #include "llvm/Analysis/Dominators.h"
 #include "llvm/Instructions.h"
 #include "llvm/Function.h"
@@ -37,6 +38,10 @@ namespace {
       AU.addRequired<DominanceFrontier>();
       AU.addRequired<TargetData>();
       AU.setPreservesCFG();
+      // This is a cluster of orthogonal Transforms
+      AU.addPreserved<UnifyFunctionExitNodes>();
+      AU.addPreservedID(LowerSelectID);
+      AU.addPreservedID(LowerSwitchID);
     }
   };
 
diff --git a/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp b/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp
index 0c1eda7c0cc..d3c7b328958 100644
--- a/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp
+++ b/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp
@@ -32,6 +32,10 @@ Pass *llvm::createUnifyFunctionExitNodesPass() {
 void UnifyFunctionExitNodes::getAnalysisUsage(AnalysisUsage &AU) const{
   // We preserve the non-critical-edgeness property
   AU.addPreservedID(BreakCriticalEdgesID);
+  // This is a cluster of orthogonal Transforms
+  AU.addPreservedID(PromoteMemoryToRegisterID);
+  AU.addPreservedID(LowerSelectID);
+  AU.addPreservedID(LowerSwitchID);
 }
 
 // UnifyAllExitNodes - Unify all exit nodes of the CFG by creating a new