Add comment.

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

diff --git a/lib/Transforms/Scalar/DCE.cpp b/lib/Transforms/Scalar/DCE.cpp
index 998d87cf1b67a0640a7ce0eff3ac2c295387e115..539dd22d47d102b54de8e61995a71e5125c91571 100644 (file)
--- a/lib/Transforms/Scalar/DCE.cpp
+++ b/lib/Transforms/Scalar/DCE.cpp
@@ -2,8 +2,8 @@
 //
 //                     The LLVM Compiler Infrastructure
 //
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
@@ -35,6 +35,8 @@ namespace {
   // DeadInstElimination pass implementation
   //
   struct VISIBILITY_HIDDEN DeadInstElimination : public BasicBlockPass {
+    static char ID; // Pass identification, replacement for typeid
+    DeadInstElimination() : BasicBlockPass(intptr_t(&ID)) {}
     virtual bool runOnBasicBlock(BasicBlock &BB) {
       bool Changed = false;
       for (BasicBlock::iterator DI = BB.begin(); DI != BB.end(); )
@@ -51,6 +53,7 @@ namespace {
     }
   };
 
+  char DeadInstElimination::ID = 0;
   RegisterPass<DeadInstElimination> X("die", "Dead Instruction Elimination");
 }
 
@@ -64,6 +67,9 @@ namespace {
   // DeadCodeElimination pass implementation
   //
   struct DCE : public FunctionPass {
+    static char ID; // Pass identification, replacement for typeid
+    DCE() : FunctionPass((intptr_t)&ID) {}
+
     virtual bool runOnFunction(Function &F);
 
      virtual void getAnalysisUsage(AnalysisUsage &AU) const {
@@ -71,6 +77,7 @@ namespace {
     }
  };
 
+  char DCE::ID = 0;
   RegisterPass<DCE> Y("dce", "Dead Code Elimination");
 }
 
@@ -102,11 +109,10 @@ bool DCE::runOnFunction(Function &F) {
       I->eraseFromParent();
 
       // Remove the instruction from the worklist if it still exists in it.
-      for (std::vector<Instruction*>::iterator WI = WorkList.begin(),
-             E = WorkList.end(); WI != E; ++WI)
+      for (std::vector<Instruction*>::iterator WI = WorkList.begin();
+           WI != WorkList.end(); ++WI)
         if (*WI == I) {
-          WorkList.erase(WI);
-          --E;
+          WI = WorkList.erase(WI);
           --WI;
         }