Avoid deleting individual instructions until AFTER dead blocks have dropped

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

diff --git a/lib/Transforms/Scalar/DCE.cpp b/lib/Transforms/Scalar/DCE.cpp
index 793b3abb6a3adf30d6446f9055f6c5bbb0830d31..fa2392fbb4248b0f44e8fe235d3158bf09857566 100644 (file)
--- a/lib/Transforms/Scalar/DCE.cpp
+++ b/lib/Transforms/Scalar/DCE.cpp
@@ -14,8 +14,12 @@
 #include "llvm/Instruction.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/InstIterator.h"
+#include "Support/StatisticReporter.h"
 #include <set>
 
+static Statistic<> DIEEliminated("die\t\t- Number of insts removed");
+static Statistic<> DCEEliminated("dce\t\t- Number of insts removed");
+
 //===----------------------------------------------------------------------===//
 // DeadInstElimination pass implementation
 //
@@ -28,9 +32,10 @@ namespace {
       BasicBlock::InstListType &Vals = BB->getInstList();
       bool Changed = false;
       for (BasicBlock::iterator DI = Vals.begin(); DI != Vals.end(); )
-        if (dceInstruction(Vals, DI))
+        if (dceInstruction(DI)) {
           Changed = true;
-        else
+          ++DIEEliminated;
+        } else
           ++DI;
       return Changed;
     }
@@ -103,6 +108,7 @@ bool DCE::runOnFunction(Function *F) {
     for (BasicBlock::iterator BI = BBIL.begin(); BI != BBIL.end(); )
       if (DeadInsts.count(*BI)) {            // Is this instruction dead?
         delete BBIL.remove(BI);              // Yup, remove and delete inst
+        ++DCEEliminated;
       } else {                               // This instruction is not dead
         ++BI;                                // Continue on to the next one...
       }