1 files changed, 24 insertions, 1 deletions

diff --git a/lib/CodeGen/UnreachableBlockElim.cpp b/lib/CodeGen/UnreachableBlockElim.cpp
index c3b213c..e7c3412 100644
--- a/lib/CodeGen/UnreachableBlockElim.cpp
+++ b/lib/CodeGen/UnreachableBlockElim.cpp
@@ -26,8 +26,11 @@
 #include "llvm/Function.h"
 #include "llvm/Pass.h"
 #include "llvm/Type.h"
+#include "llvm/Analysis/ProfileInfo.h"
+#include "llvm/CodeGen/MachineDominators.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachineLoopInfo.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/Support/CFG.h"
 #include "llvm/Support/Compiler.h"
@@ -42,6 +45,10 @@ namespace {
   public:
     static char ID; // Pass identification, replacement for typeid
     UnreachableBlockElim() : FunctionPass(&ID) {}
+
+    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+      AU.addPreserved<ProfileInfo>();
+    }
   };
 }
 char UnreachableBlockElim::ID = 0;
@@ -77,8 +84,11 @@ bool UnreachableBlockElim::runOnFunction(Function &F) {
     }
 
   // Actually remove the blocks now.
-  for (unsigned i = 0, e = DeadBlocks.size(); i != e; ++i)
+  ProfileInfo *PI = getAnalysisIfAvailable<ProfileInfo>();
+  for (unsigned i = 0, e = DeadBlocks.size(); i != e; ++i) {
+    if (PI) PI->removeBlock(DeadBlocks[i]);
     DeadBlocks[i]->eraseFromParent();
+  }
 
   return DeadBlocks.size();
 }
@@ -88,6 +98,7 @@ namespace {
   class VISIBILITY_HIDDEN UnreachableMachineBlockElim :
         public MachineFunctionPass {
     virtual bool runOnMachineFunction(MachineFunction &F);
+    virtual void getAnalysisUsage(AnalysisUsage &AU) const;
     MachineModuleInfo *MMI;
   public:
     static char ID; // Pass identification, replacement for typeid
@@ -102,10 +113,18 @@ Y("unreachable-mbb-elimination",
 
 const PassInfo *const llvm::UnreachableMachineBlockElimID = &Y;
 
+void UnreachableMachineBlockElim::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.addPreserved<MachineLoopInfo>();
+  AU.addPreserved<MachineDominatorTree>();
+  MachineFunctionPass::getAnalysisUsage(AU);
+}
+
 bool UnreachableMachineBlockElim::runOnMachineFunction(MachineFunction &F) {
   SmallPtrSet<MachineBasicBlock*, 8> Reachable;
 
   MMI = getAnalysisIfAvailable<MachineModuleInfo>();
+  MachineDominatorTree *MDT = getAnalysisIfAvailable<MachineDominatorTree>();
+  MachineLoopInfo *MLI = getAnalysisIfAvailable<MachineLoopInfo>();
 
   // Mark all reachable blocks.
   for (df_ext_iterator<MachineFunction*, SmallPtrSet<MachineBasicBlock*, 8> >
@@ -123,6 +142,10 @@ bool UnreachableMachineBlockElim::runOnMachineFunction(MachineFunction &F) {
     if (!Reachable.count(BB)) {
       DeadBlocks.push_back(BB);
 
+      // Update dominator and loop info.
+      if (MLI) MLI->removeBlock(BB);
+      if (MDT && MDT->getNode(BB)) MDT->eraseNode(BB);
+
       while (BB->succ_begin() != BB->succ_end()) {
         MachineBasicBlock* succ = *BB->succ_begin();