Index: lib/Analysis/InstructionSimplify.cpp
===================================================================
--- lib/Analysis/InstructionSimplify.cpp
+++ lib/Analysis/InstructionSimplify.cpp
@@ -1990,6 +1990,34 @@
     }
   }
 
+  // If the KnownBits of LHS and RHS at same bit position differ,
+  // LHS and RHS are not equal.
+  if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
+      uint32_t BitWidth = CI->getBitWidth();
+      APInt LHSKnownZero(BitWidth, 0, 1);
+      APInt LHSKnownOne(BitWidth, 0, 1);
+      computeKnownBits(LHS, LHSKnownZero, LHSKnownOne);
+      APInt RHSKnownZero(BitWidth, 0, 1);
+      APInt RHSKnownOne(BitWidth, 0, 1);
+      computeKnownBits(RHS, RHSKnownZero, RHSKnownOne);
+      switch (Pred) {
+      // TODO: Handle for other icmp instructions.
+      default:
+        break;
+      case ICmpInst::ICMP_EQ: {
+        if (((LHSKnownOne & RHSKnownZero) != 0) ||
+            ((LHSKnownZero & RHSKnownOne) != 0))
+          return ConstantInt::getFalse(CI->getContext());
+        break;
+      }
+      case ICmpInst::ICMP_NE:
+        if (((LHSKnownOne & RHSKnownZero) != 0) ||
+            ((LHSKnownZero & RHSKnownOne) != 0))
+          return ConstantInt::getTrue(CI->getContext());
+        break;
+      }
+    }
+
   // See if we are doing a comparison with a constant integer.
   if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
     // Rule out tautological comparisons (eg., ult 0 or uge 0).
Index: test/Transforms/InstCombine/align-2d-gep.ll
===================================================================
--- test/Transforms/InstCombine/align-2d-gep.ll
+++ test/Transforms/InstCombine/align-2d-gep.ll
@@ -31,7 +31,7 @@
   store <2 x double><double 0.0, double 0.0>, <2 x double>* %r, align 8
 
   %indvar.next = add i64 %j, 2
-  %exitcond = icmp eq i64 %indvar.next, 557
+  %exitcond = icmp eq i64 %indvar.next, 556
   br i1 %exitcond, label %bb11, label %bb1
 
 bb11:
Index: test/Transforms/InstSimplify/compare.ll
===================================================================
--- test/Transforms/InstSimplify/compare.ll
+++ test/Transforms/InstSimplify/compare.ll
@@ -883,3 +883,27 @@
 ; CHECK: ret i1 false
 }
 
+@a = common global i32 0, align 4
+@b = common global i32 0, align 4
+
+; CHECK-LABEL: @icmp_eq_const
+; CHECK-NEXT: store i32 0, i32* @b
+define void @icmp_eq_const() nounwind {
+ %1 = load i32* @a, align 4
+ %2 = mul nsw i32 %1, -2
+ %3 = icmp eq i32 %2, 1
+ %4 = zext i1 %3 to i32
+ store i32 %4, i32* @b, align 4
+ ret void
+}
+
+; CHECK-LABEL: @icmp_ne_const
+; CHECK-NEXT: store i32 1, i32* @b
+define void @icmp_ne_const() nounwind {
+ %1 = load i32* @a, align 4
+ %2 = mul nsw i32 %1, -2
+ %3 = icmp ne i32 %2, 1
+ %4 = zext i1 %3 to i32
+ store i32 %4, i32* @b, align 4
+ ret void
+}