move some functions, add a comment.

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

diff --git a/lib/Transforms/Scalar/DCE.cpp b/lib/Transforms/Scalar/DCE.cpp
index cb78207d760bc0d9b82bc1e01fee2ea63fced7de..39940c35da5d5f076857ec31822b62b2dcaf292b 100644 (file)
--- a/lib/Transforms/Scalar/DCE.cpp
+++ b/lib/Transforms/Scalar/DCE.cpp
@@ -21,7 +21,6 @@
 #include "llvm/Transforms/Utils/Local.h"
 #include "llvm/Instruction.h"
 #include "llvm/Pass.h"
-#include "llvm/Support/Compiler.h"
 #include "llvm/Support/InstIterator.h"
 #include "llvm/ADT/Statistic.h"
 #include <set>
@@ -34,17 +33,19 @@ namespace {
   //===--------------------------------------------------------------------===//
   // DeadInstElimination pass implementation
   //
-  struct VISIBILITY_HIDDEN DeadInstElimination : public BasicBlockPass {
+  struct DeadInstElimination : public BasicBlockPass {
     static char ID; // Pass identification, replacement for typeid
-    DeadInstElimination() : BasicBlockPass(intptr_t(&ID)) {}
+    DeadInstElimination() : BasicBlockPass(&ID) {}
     virtual bool runOnBasicBlock(BasicBlock &BB) {
       bool Changed = false;
-      for (BasicBlock::iterator DI = BB.begin(); DI != BB.end(); )
-        if (dceInstruction(DI)) {
+      for (BasicBlock::iterator DI = BB.begin(); DI != BB.end(); ) {
+        Instruction *Inst = DI++;
+        if (isInstructionTriviallyDead(Inst)) {
+          Inst->eraseFromParent();
           Changed = true;
           ++DIEEliminated;
-        } else
-          ++DI;
+        }
+      }
       return Changed;
     }
 
@@ -111,11 +112,12 @@ bool DCE::runOnFunction(Function &F) {
 
       // Remove the instruction from the worklist if it still exists in it.
       for (std::vector<Instruction*>::iterator WI = WorkList.begin();
-           WI != WorkList.end(); ++WI)
-        if (*WI == I) {
+           WI != WorkList.end(); ) {
+        if (*WI == I)
           WI = WorkList.erase(WI);
-          --WI;
-        }
+        else
+          ++WI;
+      }
 
       MadeChange = true;
       ++DCEEliminated;