diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/smartcasts/DataFlowValueFactory.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/smartcasts/DataFlowValueFactory.kt
index 77ddd4abe96..09141d1c64d 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/smartcasts/DataFlowValueFactory.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/smartcasts/DataFlowValueFactory.kt
@@ -89,7 +89,7 @@ object DataFlowValueFactory {
             //
             // But there are some problem with types built on type parameters, e.g.
             // fun <T : Any?> foo(x: T) = x!!.hashCode() // there no way in type system to denote that `x!!` is not nullable
-            return DataFlowValue(ExpressionIdentifierInfo(expression, false),
+            return DataFlowValue(ExpressionIdentifierInfo(expression),
                                  type,
                                  Nullability.NOT_NULL)
         }
@@ -99,7 +99,7 @@ object DataFlowValueFactory {
         }
 
         val result = getIdForStableIdentifier(expression, bindingContext, containingDeclarationOrModule)
-        return DataFlowValue(if (result === IdentifierInfo.NO) ExpressionIdentifierInfo(expression, false) else result, type)
+        return DataFlowValue(if (result === IdentifierInfo.NO) ExpressionIdentifierInfo(expression) else result, type)
     }
 
     @JvmStatic
@@ -138,7 +138,7 @@ object DataFlowValueFactory {
     private fun createDataFlowValueForComplexExpression(
             expression: KtExpression,
             type: KotlinType
-    ) = DataFlowValue(ExpressionIdentifierInfo(expression, true), type)
+    ) = DataFlowValue(ExpressionIdentifierInfo(expression, stableComplex = true), type)
 
     private data class PostfixIdentifierInfo(val argumentInfo: IdentifierInfo) : IdentifierInfo {
         override val kind: DataFlowValue.Kind get() = argumentInfo.kind
@@ -146,9 +146,9 @@ object DataFlowValueFactory {
         override fun toString() = "$argumentInfo (postfix)"
     }
 
-    class ExpressionIdentifierInfo(val expression: KtExpression, isComplex: Boolean) : IdentifierInfo {
+    class ExpressionIdentifierInfo(val expression: KtExpression, stableComplex: Boolean = false) : IdentifierInfo {
 
-        override val kind = if (isComplex) STABLE_COMPLEX_EXPRESSION else OTHER
+        override val kind = if (stableComplex) STABLE_COMPLEX_EXPRESSION else OTHER
         
         override fun equals(other: Any?) = other is ExpressionIdentifierInfo && expression == other.expression
 
diff --git a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/smartcasts/DataFlowValue.kt b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/smartcasts/DataFlowValue.kt
index adedfc61192..b72a35d2441 100644
--- a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/smartcasts/DataFlowValue.kt
+++ b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/smartcasts/DataFlowValue.kt
@@ -85,11 +85,7 @@ class DataFlowValue(val identifierInfo: IdentifierInfo,
 
     override fun toString() = "$kind $identifierInfo $immanentNullability"
 
-    override fun hashCode(): Int {
-        var result = identifierInfo.hashCode()
-        result = 31 * result + type.hashCode()
-        return result
-    }
+    override fun hashCode() = type.hashCode() + 31 * identifierInfo.hashCode()
 
     companion object {
 
diff --git a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/smartcasts/IdentifierInfo.kt b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/smartcasts/IdentifierInfo.kt
index ec9198f7e4e..86a6f1dc53b 100644
--- a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/smartcasts/IdentifierInfo.kt
+++ b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/smartcasts/IdentifierInfo.kt
@@ -49,11 +49,7 @@ interface IdentifierInfo {
         override fun equals(other: Any?) =
                 other is Variable && variable == other.variable && kind.isStable() == other.kind.isStable()
 
-        override fun hashCode(): Int {
-            var result = if (kind.isStable()) 1 else 0
-            result = 31 * result + variable.hashCode()
-            return result
-        }
+        override fun hashCode() = variable.hashCode() + 31 * (if (kind.isStable()) 1 else 0)
 
         override fun toString() = variable.toString()
     }
@@ -73,27 +69,27 @@ interface IdentifierInfo {
     }
 
     class Qualified(
-            val receiverInfo: IdentifierInfo, val selectorInfo: IdentifierInfo,
-            val safe: Boolean, val receiverType: KotlinType?
+            val receiverInfo: IdentifierInfo,
+            val selectorInfo: IdentifierInfo,
+            val safe: Boolean,
+            val receiverType: KotlinType?
     ) : IdentifierInfo {
         override val kind: DataFlowValue.Kind get() = if (receiverInfo.kind.isStable()) selectorInfo.kind else OTHER
 
         override fun equals(other: Any?) = other is Qualified && receiverInfo == other.receiverInfo && selectorInfo == other.selectorInfo
 
-        override fun hashCode(): Int {
-            var result = receiverInfo.hashCode()
-            result = 31 * result + selectorInfo.hashCode()
-            return result
-        }
+        override fun hashCode() = 31 * receiverInfo.hashCode() + selectorInfo.hashCode()
 
-        override fun toString() = "$receiverInfo(?).$selectorInfo"
+        override fun toString() = "$receiverInfo${if (safe) "?." else "."}$selectorInfo"
     }
 
     companion object {
 
         fun qualified(
-                receiverInfo: IdentifierInfo, receiverType: KotlinType?,
-                selectorInfo: IdentifierInfo, safe: Boolean
+                receiverInfo: IdentifierInfo,
+                receiverType: KotlinType?,
+                selectorInfo: IdentifierInfo,
+                safe: Boolean
         ) = when (receiverInfo) {
             NO -> NO
             is PackageOrClass -> selectorInfo