Add missing newlines at EOF (for clang++).

[oota-llvm.git] / lib / Transforms / Scalar / ADCE.cpp

diff --git a/lib/Transforms/Scalar/ADCE.cpp b/lib/Transforms/Scalar/ADCE.cpp
index f7035e576b3039dac4d1be16582662d555c6432b..37f383fb512ad0b6923b51ac5b5d00cf33c9b022 100644 (file)
--- a/lib/Transforms/Scalar/ADCE.cpp
+++ b/lib/Transforms/Scalar/ADCE.cpp
@@ -18,29 +18,22 @@
 #include "llvm/Transforms/Scalar.h"
 #include "llvm/BasicBlock.h"
 #include "llvm/Instructions.h"
+#include "llvm/IntrinsicInst.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/CFG.h"
-#include "llvm/Support/Compiler.h"
 #include "llvm/Support/InstIterator.h"
-#include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/DepthFirstIterator.h"
-#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallVector.h"
-
+#include "llvm/ADT/Statistic.h"
 using namespace llvm;
 
 STATISTIC(NumRemoved, "Number of instructions removed");
 
 namespace {
-  struct VISIBILITY_HIDDEN ADCE : public FunctionPass {
+  struct ADCE : public FunctionPass {
     static char ID; // Pass identification, replacement for typeid
-    ADCE() : FunctionPass((intptr_t)&ID) {}
-    
-    DenseSet<Instruction*> alive;
-    SmallVector<Instruction*, 1024> worklist;
-    
-    DenseSet<BasicBlock*> reachable;
-    SmallVector<BasicBlock*, 1024> unreachable;
+    ADCE() : FunctionPass(&ID) {}
     
     virtual bool runOnFunction(Function& F);
     
@@ -55,49 +48,14 @@ char ADCE::ID = 0;
 static RegisterPass<ADCE> X("adce", "Aggressive Dead Code Elimination");
 
 bool ADCE::runOnFunction(Function& F) {
-  alive.clear();
-  worklist.clear();
-  reachable.clear();
-  unreachable.clear();
-  
-  // First, collect the set of reachable blocks ...
-  for (df_iterator<BasicBlock*> DI = df_begin(&F.getEntryBlock()),
-       DE = df_end(&F.getEntryBlock()); DI != DE; ++DI)
-    reachable.insert(*DI);
-  
-  // ... and then invert it into the list of unreachable ones.  These
-  // blocks will be removed from the function.
-  for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI)
-    if (!reachable.count(FI))
-      unreachable.push_back(FI);
-  
-  // Prepare to remove blocks by removing the PHI node entries for those blocks
-  // in their successors, and remove them from reference counting.
-  for (SmallVector<BasicBlock*, 1024>::iterator UI = unreachable.begin(),
-       UE = unreachable.end(); UI != UE; ++UI) {
-    BasicBlock* BB = *UI;
-    for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB);
-         SI != SE; ++SI) {
-      BasicBlock* succ = *SI;
-      BasicBlock::iterator succ_inst = succ->begin();
-      while (PHINode* P = dyn_cast<PHINode>(succ_inst)) {
-        P->removeIncomingValue(BB);
-        ++succ_inst;
-      }
-    }
-    
-    BB->dropAllReferences();
-  }
-  
-  // Finally, erase the unreachable blocks.
-  for (SmallVector<BasicBlock*, 1024>::iterator UI = unreachable.begin(),
-       UE = unreachable.end(); UI != UE; ++UI)
-    (*UI)->eraseFromParent();
+  SmallPtrSet<Instruction*, 128> alive;
+  SmallVector<Instruction*, 128> worklist;
   
   // Collect the set of "root" instructions that are known live.
   for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I)
     if (isa<TerminatorInst>(I.getInstructionIterator()) ||
-        I->mayWriteToMemory()) {
+        isa<DbgInfoIntrinsic>(I.getInstructionIterator()) ||
+        I->mayHaveSideEffects()) {
       alive.insert(I.getInstructionIterator());
       worklist.push_back(I.getInstructionIterator());
     }
@@ -129,7 +87,7 @@ bool ADCE::runOnFunction(Function& F) {
     NumRemoved++;
     (*I)->eraseFromParent();
   }
-    
+
   return !worklist.empty();
 }