Avoid deleting individual instructions until AFTER dead blocks have dropped

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

diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp
index a115e050d17f2aa77251f21f117ef36cadaf00c4..644652691e8107ef48746b95f09d6fb80b67aa51 100644 (file)
--- a/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -5,22 +5,21 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/Transforms/Scalar/IndVarSimplify.h"
+#include "llvm/Transforms/Scalar.h"
 #include "llvm/Analysis/InductionVariable.h"
 #include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Analysis/Writer.h"
 #include "llvm/iPHINode.h"
 #include "llvm/iOther.h"
 #include "llvm/Type.h"
-#include "llvm/BasicBlock.h"
 #include "llvm/Constants.h"
-#include "llvm/Pass.h"
 #include "llvm/Support/CFG.h"
 #include "Support/STLExtras.h"
+#include "Support/StatisticReporter.h"
+
+static Statistic<> NumRemoved ("indvars\t\t- Number of aux indvars removed");
+static Statistic<> NumInserted("indvars\t\t- Number of cannonical indvars added");
 
-#if 0
-#define DEBUG
-#include "llvm/Analysis/Writer.h"
-#endif
 
 // InsertCast - Cast Val to Ty, setting a useful name on the cast if Val has a
 // name...
@@ -40,7 +39,8 @@ static bool TransformLoop(LoopInfo *Loops, Loop *Loop) {
                               std::bind1st(std::ptr_fun(TransformLoop), Loops));
   // Get the header node for this loop.  All of the phi nodes that could be
   // induction variables must live in this basic block.
-  BasicBlock *Header = (BasicBlock*)Loop->getBlocks().front();
+  //
+  BasicBlock *Header = Loop->getBlocks().front();
   
   // Loop over all of the PHI nodes in the basic block, calculating the
   // induction variables that they represent... stuffing the induction variable
@@ -109,12 +109,11 @@ static bool TransformLoop(LoopInfo *Loops, Loop *Loop) {
     assert(IndVars.back().InductionType == InductionVariable::Cannonical &&
            "Just inserted cannonical indvar that is not cannonical!");
     Cannonical = &IndVars.back();
+    ++NumInserted;
     Changed = true;
   }
 
-#ifdef DEBUG
-  cerr << "Induction variables:\n";
-#endif
+  DEBUG(cerr << "Induction variables:\n");
 
   // Get the current loop iteration count, which is always the value of the
   // cannonical phi node...
@@ -127,9 +126,9 @@ static bool TransformLoop(LoopInfo *Loops, Loop *Loop) {
   unsigned InsertPos = IndVars.size();
   for (unsigned i = 0; i < IndVars.size(); ++i) {
     InductionVariable *IV = &IndVars[i];
-#ifdef DEBUG
-    cerr << IndVars[i];
-#endif
+
+    DEBUG(cerr << IV);
+
     // Don't modify the cannonical indvar or unrecognized indvars...
     if (IV != Cannonical && IV->InductionType != InductionVariable::Unknown) {
       Instruction *Val = IterCount;
@@ -181,28 +180,31 @@ static bool TransformLoop(LoopInfo *Loops, Loop *Loop) {
       delete IV->Phi;
       InsertPos--;            // Deleted an instr, decrement insert position
       Changed = true;
+      ++NumRemoved;
     }
   }
 
   return Changed;
 }
 
-static bool doit(Function *M, LoopInfo &Loops) {
-  // Induction Variables live in the header nodes of the loops of the function
-  return reduce_apply_bool(Loops.getTopLevelLoops().begin(),
-                           Loops.getTopLevelLoops().end(),
-                           std::bind1st(std::ptr_fun(TransformLoop), &Loops));
-}
-
-
 namespace {
   struct InductionVariableSimplify : public FunctionPass {
+    const char *getPassName() const {
+      return "Induction Variable Cannonicalize";
+    }
+
     virtual bool runOnFunction(Function *F) {
-      return doit(F, getAnalysis<LoopInfo>());
+      LoopInfo &LI = getAnalysis<LoopInfo>();
+
+      // Induction Variables live in the header nodes of loops
+      return reduce_apply_bool(LI.getTopLevelLoops().begin(),
+                               LI.getTopLevelLoops().end(),
+                               std::bind1st(std::ptr_fun(TransformLoop), &LI));
     }
     
     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
       AU.addRequired(LoopInfo::ID);
+      AU.preservesCFG();
     }
   };
 }