diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/IrFunction.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/IrFunction.kt
index 7f7abaef3d2..08aca00bdad 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/IrFunction.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/IrFunction.kt
@@ -29,7 +29,10 @@ interface IrFunction : IrDeclaration, IrTypeParametersContainer {
     val valueParameters: MutableList<IrValueParameter>
 
     var body: IrBody?
+}
 
+
+interface IrSimpleFunction : IrFunction {
     override val declarationKind: IrDeclarationKind
         get() = IrDeclarationKind.FUNCTION
 }
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/impl/IrFunctionImpl.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/impl/IrFunctionImpl.kt
index 608136c6e2a..12b19d84138 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/impl/IrFunctionImpl.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/impl/IrFunctionImpl.kt
@@ -18,6 +18,7 @@ package org.jetbrains.kotlin.ir.declarations.impl
 
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.ir.declarations.IrDeclarationOrigin
+import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
 import org.jetbrains.kotlin.ir.expressions.IrBody
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitor
 
@@ -26,7 +27,7 @@ class IrFunctionImpl(
         endOffset: Int,
         origin: IrDeclarationOrigin,
         override val descriptor: FunctionDescriptor
-) : IrFunctionBase(startOffset, endOffset, origin) {
+) : IrFunctionBase(startOffset, endOffset, origin), IrSimpleFunction {
     constructor(
             startOffset: Int,
             endOffset: Int,
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DeepCopyIrTree.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DeepCopyIrTree.kt
index ce7d3f140d8..dfa3c72f3fc 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DeepCopyIrTree.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DeepCopyIrTree.kt
@@ -96,7 +96,7 @@ open class DeepCopyIrTree : IrElementTransformerVoid() {
                     mapTypeAliasDeclaration(declaration.descriptor)
             )
 
-    override fun visitFunction(declaration: IrFunction): IrFunction =
+    override fun visitSimpleFunction(declaration: IrSimpleFunction): IrSimpleFunction =
             IrFunctionImpl(
                     declaration.startOffset, declaration.endOffset,
                     mapDeclarationOrigin(declaration.origin),
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementTransformer.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementTransformer.kt
index d1f02c7687f..6ed8842252d 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementTransformer.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementTransformer.kt
@@ -37,6 +37,7 @@ interface IrElementTransformer<in D> : IrElementVisitor<IrElement, D> {
     override fun visitClass(declaration: IrClass, data: D) = visitDeclaration(declaration, data)
     override fun visitTypeAlias(declaration: IrTypeAlias, data: D) = visitDeclaration(declaration, data)
     override fun visitFunction(declaration: IrFunction, data: D) = visitDeclaration(declaration, data)
+    override fun visitSimpleFunction(declaration: IrSimpleFunction, data: D) = visitFunction(declaration, data)
     override fun visitConstructor(declaration: IrConstructor, data: D) = visitFunction(declaration, data)
     override fun visitProperty(declaration: IrProperty, data: D) = visitDeclaration(declaration, data)
     override fun visitField(declaration: IrField, data: D) = visitDeclaration(declaration, data)
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementTransformerVoid.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementTransformerVoid.kt
index 1c90523658a..c941b7d1bee 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementTransformerVoid.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementTransformerVoid.kt
@@ -43,6 +43,9 @@ abstract class IrElementTransformerVoid : IrElementTransformer<Nothing?> {
     open fun visitFunction(declaration: IrFunction) = visitDeclaration(declaration)
     override final fun visitFunction(declaration: IrFunction, data: Nothing?) = visitFunction(declaration)
 
+    open fun visitSimpleFunction(declaration: IrSimpleFunction) = visitFunction(declaration)
+    override final fun visitSimpleFunction(declaration: IrSimpleFunction, data: Nothing?) = visitSimpleFunction(declaration)
+
     open fun visitConstructor(declaration: IrConstructor) = visitFunction(declaration)
     override final fun visitConstructor(declaration: IrConstructor, data: Nothing?) = visitConstructor(declaration)
 
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementVisitor.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementVisitor.kt
index 432d08641ec..d094e5e9589 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementVisitor.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementVisitor.kt
@@ -29,6 +29,7 @@ interface IrElementVisitor<out R, in D> {
     fun visitClass(declaration: IrClass, data: D) = visitDeclaration(declaration, data)
     fun visitTypeAlias(declaration: IrTypeAlias, data: D) = visitDeclaration(declaration, data)
     fun visitFunction(declaration: IrFunction, data: D) = visitDeclaration(declaration, data)
+    fun visitSimpleFunction(declaration: IrSimpleFunction, data: D) = visitFunction(declaration, data)
     fun visitConstructor(declaration: IrConstructor, data: D) = visitFunction(declaration, data)
     fun visitProperty(declaration: IrProperty, data: D) = visitDeclaration(declaration, data)
     fun visitField(declaration: IrField, data: D) = visitDeclaration(declaration, data)
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementVisitorVoid.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementVisitorVoid.kt
index 145d73ea3ae..2e660586ffc 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementVisitorVoid.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/visitors/IrElementVisitorVoid.kt
@@ -42,6 +42,9 @@ interface IrElementVisitorVoid : IrElementVisitor<Unit, Nothing?> {
     fun visitFunction(declaration: IrFunction) = visitDeclaration(declaration)
     override fun visitFunction(declaration: IrFunction, data: Nothing?) = visitFunction(declaration)
 
+    fun visitSimpleFunction(declaration: IrSimpleFunction) = visitFunction(declaration)
+    override fun visitSimpleFunction(declaration: IrSimpleFunction, data: Nothing?) = visitSimpleFunction(declaration)
+
     fun visitConstructor(declaration: IrConstructor) = visitFunction(declaration)
     override fun visitConstructor(declaration: IrConstructor, data: Nothing?) = visitConstructor(declaration)
 
@@ -168,6 +171,9 @@ interface IrElementVisitorVoid : IrElementVisitor<Unit, Nothing?> {
     fun visitBranch(branch: IrBranch) = visitElement(branch)
     override fun visitBranch(branch: IrBranch, data: Nothing?) = visitBranch(branch)
 
+    fun visitElseBranch(branch: IrElseBranch) = visitBranch(branch)
+    override fun visitElseBranch(branch: IrElseBranch, data: Nothing?) = visitElseBranch(branch)
+
     fun visitLoop(loop: IrLoop) = visitExpression(loop)
     override fun visitLoop(loop: IrLoop, data: Nothing?) = visitLoop(loop)