Index: lib/Transforms/Scalar/SCCP.cpp
===================================================================
--- lib/Transforms/Scalar/SCCP.cpp
+++ lib/Transforms/Scalar/SCCP.cpp
@@ -71,8 +71,6 @@
 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 {
 
@@ -1041,15 +1039,23 @@
 
 // Handle ICmpInst instruction.
 void SCCPSolver::visitCmpInst(CmpInst &I) {
-  LatticeVal V1State = getValueState(I.getOperand(0));
-  LatticeVal V2State = getValueState(I.getOperand(1));
+  ValueLatticeElement V1State = getValueState(I.getOperand(0)).toValueLattice();
+  ValueLatticeElement V2State = getValueState(I.getOperand(1)).toValueLattice();
 
   LatticeVal &IV = ValueState[&I];
   if (IV.isOverdefined()) return;
 
-  if (V1State.isConstant() && V2State.isConstant()) {
-    Constant *C = ConstantExpr::getCompare(
-        I.getPredicate(), V1State.getConstant(), V2State.getConstant());
+  // For parameters, use ParamState which includes constant range info if
+  // available.
+  auto V1Param = ParamState.find(I.getOperand(0));
+  auto V2Param = ParamState.find(I.getOperand(1));
+  if (V1Param != ParamState.end())
+    V1State = V1Param->second;
+  if (V2Param != ParamState.end())
+    V2State = V2Param->second;
+
+  Constant *C = V1State.getCompare(I.getPredicate(), I.getType(), V2State);
+  if (C) {
     if (isa<UndefValue>(C))
       return;
     return markConstant(IV, &I, C);
@@ -1618,45 +1624,6 @@
   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()) {
@@ -1925,9 +1892,6 @@
           ++IPNumArgsElimed;
           continue;
         }
-
-        if (!AI->use_empty() && tryToReplaceWithConstantRange(Solver, &*AI))
-          ++IPNumRangeInfoUsed;
       }
 
     for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
Index: test/Transforms/SCCP/ip-constant-ranges.ll
===================================================================
--- test/Transforms/SCCP/ip-constant-ranges.ll
+++ test/Transforms/SCCP/ip-constant-ranges.ll
@@ -2,11 +2,7 @@
 
 ; Constant range for %a is [1, 48) and for %b is [301, 1000)
 ; CHECK-LABEL: f1
-; CHECK-NOT: icmp
-; CHECK: %a.1 = select i1 false, i32 1, i32 2
-; CHECK: %b.1 = select i1 true, i32 1, i32 2
-; CHECK: %a.2 = select i1 false, i32 1, i32 2
-; CHECK: %b.2 = select i1 true, i32 1, i32 2
+; CHECK: ret i32 undef
 define internal i32 @f1(i32 %a, i32 %b) {
 entry:
   %cmp.a = icmp sgt i32 %a, 300
@@ -28,10 +24,11 @@
 ; CHECK-LABEL: f2
 ; CHECK: %cmp = icmp sgt i32 %x, 300
 ; CHECK: %res1 = select i1 %cmp, i32 1, i32 2
-; CHECK-NEXT: %res2 = select i1 true, i32 3, i32 4
-; CHECK-NEXT: %res3 = select i1 true, i32 5, i32 6
 ; CHECK-NEXT: %res4 = select i1 %cmp4, i32 3, i32 4
-; CHECK-NEXT: %res5 = select i1 true, i32 5, i32 6
+; CHECK-NEXT: %res6 = add i32 %res1, 3
+; CHECK-NEXT: %res7 = add i32 5, %res4
+; CHECK-NEXT: %res = add i32 %res6, 5
+; CHECK-NEXT: ret i32 %res
 define internal i32 @f2(i32 %x) {
 entry:
   %cmp = icmp sgt i32 %x, 300
@@ -57,8 +54,7 @@
   %call2 = tail call i32 @f1(i32 47, i32 999)
   %call3 = tail call i32 @f2(i32 47)
   %call4 = tail call i32 @f2(i32 301)
-  %res = add nsw i32 %call1, %call2
-  %res.1 = add nsw i32 %res, %call3
+  %res.1 = add nsw i32 12, %call3
   %res.2 = add nsw i32 %res.1, %call4
   ret i32 %res.2
 }
@@ -145,9 +141,9 @@
 ; Constant range for %x is [47, 302)
 ; CHECK-LABEL: @f5
 ; CHECK-NEXT: entry:
-; CHECK-NEXT: %res1 = select i1 undef, i32 1, i32 2
-; CHECK-NEXT: %res2 = select i1 undef, i32 3, i32 4
-; CHECK-NEXT: %res = add i32 %res1, %res2
+; CHECK-NEXT: %cmp = icmp sgt i32 %x, undef
+; CHECK-NEXT: %res1 = select i1 %cmp, i32 1, i32 2
+; CHECK-NEXT: %res = add i32 %res1, 3
 ; CHECK-NEXT: ret i32 %res
 define internal i32 @f5(i32 %x) {
 entry: