From: Dale Johannesen <dalej@apple.com>
Date: Fri, 19 Feb 2010 01:54:37 +0000 (+0000)
Subject: Revert 96626, which causes build failure on ppc Darwin.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=efd9e9505167a398ba3c4924b09a47bd4d688e51;p=oota-llvm.git

Revert 96626, which causes build failure on ppc Darwin.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96653 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/Analysis/ScalarEvolution.h b/include/llvm/Analysis/ScalarEvolution.h
index af5d10e6b78..383ee88ad28 100644
--- a/include/llvm/Analysis/ScalarEvolution.h
+++ b/include/llvm/Analysis/ScalarEvolution.h
@@ -586,11 +586,6 @@ namespace llvm {
     /// compute a trip count, or if the loop is deleted.
     void forgetLoop(const Loop *L);
 
-    /// forgetValue - This method should be called by the client when it has
-    /// changed a value in a way that may effect its value, or which may
-    /// disconnect it from a def-use chain linking it to a loop.
-    void forgetValue(Value *V);
-
     /// GetMinTrailingZeros - Determine the minimum number of zero bits that S
     /// is guaranteed to end in (at every loop iteration).  It is, at the same
     /// time, the minimum number of times S is divisible by 2.  For example,
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index c2284a8ab9b..82200cd0281 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -3485,35 +3485,6 @@ void ScalarEvolution::forgetLoop(const Loop *L) {
   }
 }
 
-/// forgetValue - This method should be called by the client when it has
-/// changed a value in a way that may effect its value, or which may
-/// disconnect it from a def-use chain linking it to a loop.
-void ScalarEvolution::forgetValue(Value *V) {
-  Instruction *I = dyn_cast<Instruction>(V);
-  if (!I) return;
-
-  // Drop information about expressions based on loop-header PHIs.
-  SmallVector<Instruction *, 16> Worklist;
-  Worklist.push_back(I);
-
-  SmallPtrSet<Instruction *, 8> Visited;
-  while (!Worklist.empty()) {
-    I = Worklist.pop_back_val();
-    if (!Visited.insert(I)) continue;
-
-    std::map<SCEVCallbackVH, const SCEV *>::iterator It =
-      Scalars.find(static_cast<Value *>(I));
-    if (It != Scalars.end()) {
-      ValuesAtScopes.erase(It->second);
-      Scalars.erase(It);
-      if (PHINode *PN = dyn_cast<PHINode>(I))
-        ConstantEvolutionLoopExitValue.erase(PN);
-    }
-
-    PushDefUseChildren(I, Worklist);
-  }
-}
-
 /// ComputeBackedgeTakenCount - Compute the number of times the backedge
 /// of the specified loop will execute.
 ScalarEvolution::BackedgeTakenInfo
diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp
index 60492b02836..e699261b277 100644
--- a/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -246,13 +246,6 @@ void IndVarSimplify::RewriteLoopExitValues(Loop *L,
       if (!PN->getType()->isIntegerTy() && !PN->getType()->isPointerTy())
         continue;
 
-      // It's necessary to tell ScalarEvolution about this explicitly so that
-      // it can walk the def-use list and forget all SCEVs, as it may not be
-      // watching the PHI itself. Once the new exit value is in place, there
-      // may not be a def-use connection between the loop and every instruction
-      // which got a SCEVAddRecExpr for that loop.
-      SE->forgetValue(PN);
-
       // Iterate over all of the values in all the PHI nodes.
       for (unsigned i = 0; i != NumPreds; ++i) {
         // If the value being merged in is not integer or is not defined