1 files changed, 17 insertions, 50 deletions

diff --git a/llvm/lib/Transforms/Scalar/SCCP.cpp b/llvm/lib/Transforms/Scalar/SCCP.cpp
index 5a6697fd9fe..d6fbbce23a3 100644
--- a/llvm/lib/Transforms/Scalar/SCCP.cpp
+++ b/llvm/lib/Transforms/Scalar/SCCP.cpp
@@ -69,8 +69,6 @@ STATISTIC(NumDeadBlocks , "Number of basic blocks unreachable");
 STATISTIC(IPNumInstRemoved, "Number of instructions removed by IPSCCP");
 STATISTIC(IPNumArgsElimed ,"Number of arguments constant propagated by IPSCCP");
 STATISTIC(IPNumGlobalConst, "Number of globals found to be constant by IPSCCP");
-STATISTIC(IPNumRangeInfoUsed, "Number of times constant range info was used by"
-                              "IPSCCP");
 
 namespace {
 
@@ -1039,15 +1037,26 @@ void SCCPSolver::visitBinaryOperator(Instruction &I) {
 
 // Handle ICmpInst instruction.
 void SCCPSolver::visitCmpInst(CmpInst &I) {
-  LatticeVal V1State = getValueState(I.getOperand(0));
-  LatticeVal V2State = getValueState(I.getOperand(1));
-
   LatticeVal &IV = ValueState[&I];
   if (IV.isOverdefined()) return;
 
-  if (V1State.isConstant() && V2State.isConstant()) {
-    Constant *C = ConstantExpr::getCompare(
-        I.getPredicate(), V1State.getConstant(), V2State.getConstant());
+  Value *Op1 = I.getOperand(0);
+  Value *Op2 = I.getOperand(1);
+
+  // For parameters, use ParamState which includes constant range info if
+  // available.
+  auto V1Param = ParamState.find(Op1);
+  ValueLatticeElement V1State = (V1Param != ParamState.end())
+                                    ? V1Param->second
+                                    : getValueState(Op1).toValueLattice();
+
+  auto V2Param = ParamState.find(Op2);
+  ValueLatticeElement V2State = V2Param != ParamState.end()
+                                    ? V2Param->second
+                                    : getValueState(Op2).toValueLattice();
+
+  Constant *C = V1State.getCompare(I.getPredicate(), I.getType(), V2State);
+  if (C) {
     if (isa<UndefValue>(C))
       return;
     return markConstant(IV, &I, C);
@@ -1616,45 +1625,6 @@ bool SCCPSolver::ResolvedUndefsIn(Function &F) {
   return false;
 }
 
-static bool tryToReplaceWithConstantRange(SCCPSolver &Solver, Value *V) {
-  bool Changed = false;
-
-  // Currently we only use range information for integer values.
-  if (!V->getType()->isIntegerTy())
-    return false;
-
-  const ValueLatticeElement &IV = Solver.getLatticeValueFor(V);
-  if (!IV.isConstantRange())
-    return false;
-
-  for (auto UI = V->uses().begin(), E = V->uses().end(); UI != E;) {
-    const Use &U = *UI++;
-    auto *Icmp = dyn_cast<ICmpInst>(U.getUser());
-    if (!Icmp || !Solver.isBlockExecutable(Icmp->getParent()))
-      continue;
-
-    auto getIcmpLatticeValue = [&](Value *Op) {
-      if (auto *C = dyn_cast<Constant>(Op))
-        return ValueLatticeElement::get(C);
-      return Solver.getLatticeValueFor(Op);
-    };
-
-    ValueLatticeElement A = getIcmpLatticeValue(Icmp->getOperand(0));
-    ValueLatticeElement B = getIcmpLatticeValue(Icmp->getOperand(1));
-
-    Constant *C = A.getCompare(Icmp->getPredicate(), Icmp->getType(), B);
-    if (C) {
-      Icmp->replaceAllUsesWith(C);
-      DEBUG(dbgs() << "Replacing " << *Icmp << " with " << *C
-                   << ", because of range information " << A << " " << B
-                   << "\n");
-      Icmp->eraseFromParent();
-      Changed = true;
-    }
-  }
-  return Changed;
-}
-
 static bool tryToReplaceWithConstant(SCCPSolver &Solver, Value *V) {
   Constant *Const = nullptr;
   if (V->getType()->isStructTy()) {
@@ -1923,9 +1893,6 @@ bool llvm::runIPSCCP(Module &M, const DataLayout &DL,
           ++IPNumArgsElimed;
           continue;
         }
-
-        if (!AI->use_empty() && tryToReplaceWithConstantRange(Solver, &*AI))
-          ++IPNumRangeInfoUsed;
       }
 
     for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {