Index: llvm/include/llvm/Analysis/ValueLattice.h
===================================================================
--- llvm/include/llvm/Analysis/ValueLattice.h
+++ llvm/include/llvm/Analysis/ValueLattice.h
@@ -11,6 +11,7 @@
 
 #include "llvm/IR/ConstantRange.h"
 #include "llvm/IR/Constants.h"
+#include "llvm/IR/Instructions.h"
 //
 //===----------------------------------------------------------------------===//
 //                               ValueLatticeElement
@@ -456,6 +457,16 @@
     if (isConstant() && Other.isConstant())
       return ConstantExpr::getCompare(Pred, getConstant(), Other.getConstant());
 
+    if (ICmpInst::isEquality(Pred)) {
+      // not(C) != C => true, not(C) == C => false.
+      if ((isNotConstant() && Other.isConstant() &&
+           getNotConstant() == Other.getConstant()) ||
+          (isConstant() && Other.isNotConstant() &&
+           getConstant() == Other.getNotConstant()))
+        return Pred == ICmpInst::ICMP_NE
+            ? ConstantInt::getTrue(Ty) : ConstantInt::getFalse(Ty);
+    }
+
     // Integer constants are represented as ConstantRanges with single
     // elements.
     if (!isConstantRange() || !Other.isConstantRange())
Index: llvm/lib/Transforms/Scalar/SCCP.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/SCCP.cpp
+++ llvm/lib/Transforms/Scalar/SCCP.cpp
@@ -103,8 +103,7 @@
 // ValueLatticeElement::isOverdefined() and is intended to be used in the
 // transition to ValueLatticeElement.
 bool isOverdefined(const ValueLatticeElement &LV) {
-  return LV.isOverdefined() ||
-         (LV.isConstantRange() && !LV.getConstantRange().isSingleElement());
+  return !LV.isUnknownOrUndef() && !isConstant(LV);
 }
 
 //===----------------------------------------------------------------------===//
@@ -1109,7 +1108,9 @@
     if (I->getType()->isIntegerTy())
       return ValueLatticeElement::getRange(
           getConstantRangeFromMetadata(*Ranges));
-  // TODO: Also handle MD_nonnull.
+  if (I->hasMetadata(LLVMContext::MD_nonnull))
+    return ValueLatticeElement::getNot(
+        ConstantPointerNull::get(cast<PointerType>(I->getType())));
   return ValueLatticeElement::getOverdefined();
 }
 
@@ -1319,6 +1320,12 @@
         addAdditionalUser(OtherOp, &CB);
         mergeInValue(IV, &CB, CondVal);
         return;
+      } else if (Pred == CmpInst::ICMP_NE && CondVal.isConstant()) {
+        // Propagate inequalities.
+        addAdditionalUser(OtherOp, &CB);
+        mergeInValue(IV, &CB,
+                     ValueLatticeElement::getNot(CondVal.getConstant()));
+        return;
       }
 
       return (void)mergeInValue(IV, &CB, CopyOfVal);
Index: llvm/test/Transforms/SCCP/conditions-ranges.ll
===================================================================
--- llvm/test/Transforms/SCCP/conditions-ranges.ll
+++ llvm/test/Transforms/SCCP/conditions-ranges.ll
@@ -85,7 +85,6 @@
   ret void
 }
 
-; TODO: Use information %a != 0 in false branch.
 define void @f2_ptr(i8* %a, i8* %b) {
 ; CHECK-LABEL: @f2_ptr(
 ; CHECK-NEXT:  entry:
@@ -98,10 +97,8 @@
 ; CHECK-NEXT:    call void @use(i1 [[C_1]])
 ; CHECK-NEXT:    ret void
 ; CHECK:       false:
-; CHECK-NEXT:    [[F_2:%.*]] = icmp eq i8* [[A]], null
-; CHECK-NEXT:    call void @use(i1 [[F_2]])
-; CHECK-NEXT:    [[T_2:%.*]] = icmp ne i8* [[A]], null
-; CHECK-NEXT:    call void @use(i1 [[T_2]])
+; CHECK-NEXT:    call void @use(i1 false)
+; CHECK-NEXT:    call void @use(i1 true)
 ; CHECK-NEXT:    [[C_2:%.*]] = icmp eq i8* [[A]], [[B]]
 ; CHECK-NEXT:    call void @use(i1 [[C_2]])
 ; CHECK-NEXT:    ret void
@@ -236,7 +233,7 @@
 ; CHECK-NEXT:    call void @use(i1 true)
 ; CHECK-NEXT:    ret void
 ; CHECK:       true:
-; CHECK-NEXT:    store i32 [[B:%.*]], i32* [[A]]
+; CHECK-NEXT:    store i32 [[B:%.*]], i32* [[A]], align 4
 ; CHECK-NEXT:    ret void
 ;
 entry:
Index: llvm/test/Transforms/SCCP/metadata.ll
===================================================================
--- llvm/test/Transforms/SCCP/metadata.ll
+++ llvm/test/Transforms/SCCP/metadata.ll
@@ -48,14 +48,10 @@
 ; CHECK-LABEL: @load_nonnull(
 ; CHECK-NEXT:    [[V:%.*]] = load i32*, i32** [[P:%.*]], align 8, !nonnull !2
 ; CHECK-NEXT:    [[V2:%.*]] = load i32*, i32** [[P2:%.*]], align 8, !nonnull !2
-; CHECK-NEXT:    [[C1:%.*]] = icmp ne i32* [[V]], null
-; CHECK-NEXT:    call void @use(i1 [[C1]])
-; CHECK-NEXT:    [[C2:%.*]] = icmp eq i32* [[V]], null
-; CHECK-NEXT:    call void @use(i1 [[C2]])
-; CHECK-NEXT:    [[C3:%.*]] = icmp ne i32* null, [[V]]
-; CHECK-NEXT:    call void @use(i1 [[C3]])
-; CHECK-NEXT:    [[C4:%.*]] = icmp eq i32* null, [[V]]
-; CHECK-NEXT:    call void @use(i1 [[C4]])
+; CHECK-NEXT:    call void @use(i1 true)
+; CHECK-NEXT:    call void @use(i1 false)
+; CHECK-NEXT:    call void @use(i1 true)
+; CHECK-NEXT:    call void @use(i1 false)
 ; CHECK-NEXT:    [[C5:%.*]] = icmp eq i32* [[V]], [[V2]]
 ; CHECK-NEXT:    call void @use(i1 [[C5]])
 ; CHECK-NEXT:    [[C6:%.*]] = icmp ne i32* [[V]], [[V2]]