diff --git a/llvm/include/llvm/Analysis/BasicAliasAnalysis.h b/llvm/include/llvm/Analysis/BasicAliasAnalysis.h
--- a/llvm/include/llvm/Analysis/BasicAliasAnalysis.h
+++ b/llvm/include/llvm/Analysis/BasicAliasAnalysis.h
@@ -104,7 +104,6 @@
   /// call site is not known.
   FunctionModRefBehavior getModRefBehavior(const Function *Fn);
 
-private:
   // A linear transformation of a Value; this class represents ZExt(SExt(V,
   // SExtBits), ZExtBits) * Scale + Offset.
   struct VariableGEPIndex {
@@ -174,6 +173,7 @@
   static bool DecomposeGEPExpression(const Value *V, DecomposedGEP &Decomposed,
       const DataLayout &DL, AssumptionCache *AC, DominatorTree *DT);
 
+private:
   static bool isGEPBaseAtNegativeOffset(const GEPOperator *GEPOp,
       const DecomposedGEP &DecompGEP, const DecomposedGEP &DecompObject,
       LocationSize ObjectAccessSize);
diff --git a/llvm/lib/Transforms/Scalar/SCCP.cpp b/llvm/lib/Transforms/Scalar/SCCP.cpp
--- a/llvm/lib/Transforms/Scalar/SCCP.cpp
+++ b/llvm/lib/Transforms/Scalar/SCCP.cpp
@@ -26,6 +26,7 @@
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/BasicAliasAnalysis.h"
 #include "llvm/Analysis/ConstantFolding.h"
 #include "llvm/Analysis/DomTreeUpdater.h"
 #include "llvm/Analysis/GlobalsModRef.h"
@@ -1264,6 +1265,14 @@
   }
 }
 
+static unsigned getMaxPointerSize(const DataLayout &DL) {
+  unsigned MaxPointerSize = DL.getMaxPointerSizeInBits();
+  if (MaxPointerSize < 64)
+    MaxPointerSize = 64;
+
+  return MaxPointerSize;
+}
+
 void SCCPSolver::handleCallResult(CallBase &CB) {
   Function *F = CB.getCalledFunction();
 
@@ -1333,6 +1342,27 @@
             ValueLatticeElement::getRange(NewCR, MayIncludeUndef));
         return;
       } else if (Pred == CmpInst::ICMP_EQ && CondVal.isConstant()) {
+        Constant *C = CondVal.getConstant();
+
+        // Do not propagate equality of a un-dereferenceable pointer.
+        // FIXME: Currently this only treats pointers one past the last element
+        // for array types. Should probably be much stricter.
+        if (C->getType()->isPointerTy()) {
+          BasicAAResult::DecomposedGEP Dec;
+          unsigned MaxPointerSize = getMaxPointerSize(DL);
+          Dec.StructOffset = Dec.OtherOffset = APInt(MaxPointerSize, 0);
+          Dec.StructOffset = Dec.OtherOffset = APInt(MaxPointerSize, 0);
+
+          BasicAAResult::DecomposeGEPExpression(C, Dec, DL, nullptr, nullptr);
+          auto *BaseTy = Dec.Base->getType()->getPointerElementType();
+          if (BaseTy->isArrayTy() &&
+              DL.getTypeSizeInBits(
+                  Dec.Base->getType()->getPointerElementType()) /
+                      8 ==
+                  Dec.OtherOffset) {
+            return (void)mergeInValue(IV, &CB, CopyOfVal);
+          }
+        }
         // For non-integer values or integer constant expressions, only
         // propagate equal constants.
         addAdditionalUser(OtherOp, &CB);
diff --git a/llvm/test/Transforms/SCCP/replace-dereferenceable-ptr-with-undereferenceable.ll b/llvm/test/Transforms/SCCP/replace-dereferenceable-ptr-with-undereferenceable.ll
--- a/llvm/test/Transforms/SCCP/replace-dereferenceable-ptr-with-undereferenceable.ll
+++ b/llvm/test/Transforms/SCCP/replace-dereferenceable-ptr-with-undereferenceable.ll
@@ -11,7 +11,7 @@
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32* [[P:%.*]], getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1)
 ; CHECK-NEXT:    br i1 [[CMP]], label [[IF_THEN:%.*]], label [[IF_END:%.*]]
 ; CHECK:       if.then:
-; CHECK-NEXT:    store i32 2, i32* getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1), align 4
+; CHECK-NEXT:    store i32 2, i32* [[P]], align 4
 ; CHECK-NEXT:    br label [[IF_END]]
 ; CHECK:       if.end:
 ; CHECK-NEXT:    [[TMP0:%.*]] = load i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @y, i64 0, i64 0), align 4