diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/CallAndReferenceGenerator.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/CallAndReferenceGenerator.kt
index 467d758cfbd..668dca6fb54 100644
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/CallAndReferenceGenerator.kt
+++ b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/CallAndReferenceGenerator.kt
@@ -288,10 +288,10 @@ class CallAndReferenceGenerator(
         val startOffset = adapteeFunction.startOffset
         val endOffset = adapteeFunction.endOffset
         val type = adapteeFunction.returnType
-        val irCall =
-            if (adapteeSymbol is IrConstructorSymbol) {
+        val irCall = when (adapteeSymbol) {
+            is IrConstructorSymbol ->
                 IrConstructorCallImpl.fromSymbolOwner(startOffset, endOffset, type, adapteeSymbol)
-            } else {
+            is IrSimpleFunctionSymbol ->
                 IrCallImpl(
                     startOffset,
                     endOffset,
@@ -302,7 +302,9 @@ class CallAndReferenceGenerator(
                     origin = null,
                     superQualifierSymbol = null
                 )
-            }
+            else ->
+                error("unknown callee kind: ${adapteeFunction.render()}")
+        }
 
         if (boundDispatchReceiver != null || boundExtensionReceiver != null) {
             val receiverValue = IrGetValueImpl(
diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/DefaultArgumentStubGenerator.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/DefaultArgumentStubGenerator.kt
index 58e1761ac5d..5a417243b9f 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/DefaultArgumentStubGenerator.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/DefaultArgumentStubGenerator.kt
@@ -341,7 +341,7 @@ open class DefaultParameterInjector(
         return visitFunctionAccessExpression(expression) {
             with(expression) {
                 IrCallImpl(
-                    startOffset, endOffset, type, it,
+                    startOffset, endOffset, type, it as IrSimpleFunctionSymbol,
                     typeArgumentsCount = typeArgumentsCount,
                     valueArgumentsCount = it.owner.valueParameters.size,
                     origin = DEFAULT_DISPATCH_CALL,
diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/LocalDeclarationsLowering.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/LocalDeclarationsLowering.kt
index 4604ae0aac4..361ff78f045 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/LocalDeclarationsLowering.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/LocalDeclarationsLowering.kt
@@ -509,7 +509,7 @@ class LocalDeclarationsLowering(
             rewriteFunctionBody(irElement, null)
         }
 
-        private fun createNewCall(oldCall: IrCall, newCallee: IrFunction) =
+        private fun createNewCall(oldCall: IrCall, newCallee: IrSimpleFunction) =
             IrCallImpl(
                 oldCall.startOffset, oldCall.endOffset,
                 newCallee.returnType,
diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/inline/FunctionInlining.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/inline/FunctionInlining.kt
index 4f9a1fb96b5..f1c8e9afff1 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/inline/FunctionInlining.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/inline/FunctionInlining.kt
@@ -234,17 +234,22 @@ class FunctionInlining(
                     }
 
                     val immediateCall = with(expression) {
-                        if (function is IrConstructor) {
-                            val classTypeParametersCount = function.parentAsClass.typeParameters.size
-                            IrConstructorCallImpl.fromSymbolOwner(
-                                startOffset,
-                                endOffset,
-                                function.returnType,
-                                function.symbol,
-                                classTypeParametersCount
-                            )
-                        } else
-                            IrCallImpl(startOffset, endOffset, function.returnType, functionArgument.symbol)
+                        when (function) {
+                            is IrConstructor -> {
+                                val classTypeParametersCount = function.parentAsClass.typeParameters.size
+                                IrConstructorCallImpl.fromSymbolOwner(
+                                    startOffset,
+                                    endOffset,
+                                    function.returnType,
+                                    function.symbol,
+                                    classTypeParametersCount
+                                )
+                            }
+                            is IrSimpleFunction ->
+                                IrCallImpl(startOffset, endOffset, function.returnType, function.symbol)
+                            else ->
+                                error("Unknown function kind : ${function.render()}")
+                        }
                     }.apply {
                         for (parameter in functionParameters) {
                             val argument =
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/ir/IrBuilder.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/ir/IrBuilder.kt
index 8f568fc2ce3..25183a4a914 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/ir/IrBuilder.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/ir/IrBuilder.kt
@@ -21,7 +21,7 @@ object JsIrBuilder {
     object SYNTHESIZED_STATEMENT : IrStatementOriginImpl("SYNTHESIZED_STATEMENT")
     object SYNTHESIZED_DECLARATION : IrDeclarationOriginImpl("SYNTHESIZED_DECLARATION")
 
-    fun buildCall(target: IrFunctionSymbol, type: IrType? = null, typeArguments: List<IrType>? = null): IrCall {
+    fun buildCall(target: IrSimpleFunctionSymbol, type: IrType? = null, typeArguments: List<IrType>? = null): IrCall {
         val owner = target.owner
         return IrCallImpl(
             UNDEFINED_OFFSET,
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/CallableReferenceLowering.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/CallableReferenceLowering.kt
index 9509b3e6b33..44de8ad3a2a 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/CallableReferenceLowering.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/CallableReferenceLowering.kt
@@ -22,10 +22,7 @@ import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.types.IrSimpleType
 import org.jetbrains.kotlin.ir.types.IrTypeProjection
 import org.jetbrains.kotlin.ir.types.classOrNull
-import org.jetbrains.kotlin.ir.util.defaultType
-import org.jetbrains.kotlin.ir.util.explicitParameters
-import org.jetbrains.kotlin.ir.util.isSuspend
-import org.jetbrains.kotlin.ir.util.parentAsClass
+import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
 import org.jetbrains.kotlin.name.Name
@@ -220,10 +217,30 @@ class CallableReferenceLowering(private val context: CommonBackendContext) : Bod
         private fun IrSimpleFunction.buildInvoke(): IrFunctionAccessExpression {
             val callee = function
             val irCall =  reference.run {
-                if (callee is IrConstructor) {
-                    IrConstructorCallImpl(startOffset, endOffset, callee.parentAsClass.defaultType, callee.symbol, callee.typeParameters.size, 0 /* TODO */, callee.valueParameters.size, CALLABLE_REFERENCE_INVOKE)
-                } else {
-                    IrCallImpl(startOffset, endOffset, callee.returnType, callee.symbol, callee.typeParameters.size, callee.valueParameters.size, CALLABLE_REFERENCE_INVOKE)
+                when (callee) {
+                    is IrConstructor ->
+                        IrConstructorCallImpl(
+                            startOffset,
+                            endOffset,
+                            callee.parentAsClass.defaultType,
+                            callee.symbol,
+                            callee.typeParameters.size,
+                            0 /* TODO */,
+                            callee.valueParameters.size,
+                            CALLABLE_REFERENCE_INVOKE
+                        )
+                    is IrSimpleFunction ->
+                        IrCallImpl(
+                            startOffset,
+                            endOffset,
+                            callee.returnType,
+                            callee.symbol,
+                            callee.typeParameters.size,
+                            callee.valueParameters.size,
+                            CALLABLE_REFERENCE_INVOKE
+                        )
+                    else ->
+                        error("unknown function kind: ${callee.render()}")
                 }
             }
 
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/CreateScriptFunctionsPhase.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/CreateScriptFunctionsPhase.kt
index fef1e1f3cc5..dc399ea1044 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/CreateScriptFunctionsPhase.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/CreateScriptFunctionsPhase.kt
@@ -121,7 +121,7 @@ class CreateScriptFunctionsPhase(val context: CommonBackendContext) : FileLoweri
         )
     }
 
-    private fun createCall(function: IrFunction): IrCall {
+    private fun createCall(function: IrSimpleFunction): IrCall {
         return IrCallImpl(
             UNDEFINED_OFFSET, UNDEFINED_OFFSET, function.returnType,
             function.symbol,
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/calls/CallsLoweringUtils.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/calls/CallsLoweringUtils.kt
index 25dd02d5b13..4fe7bb0ac8f 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/calls/CallsLoweringUtils.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/calls/CallsLoweringUtils.kt
@@ -5,19 +5,19 @@
 
 package org.jetbrains.kotlin.ir.backend.js.lower.calls
 
-import org.jetbrains.kotlin.ir.declarations.IrFunction
+import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
 import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.IrFunctionAccessExpression
 import org.jetbrains.kotlin.ir.symbols.IrClassifierSymbol
 import org.jetbrains.kotlin.ir.symbols.IrFunctionSymbol
+import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
 import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.util.irCall
 import org.jetbrains.kotlin.name.Name
-import org.jetbrains.kotlin.types.SimpleType
 
 typealias SymbolToTransformer = MutableMap<IrFunctionSymbol, (IrFunctionAccessExpression) -> IrExpression>
 
-internal fun SymbolToTransformer.add(from: Map<IrClassifierSymbol, IrFunctionSymbol>, to: IrFunctionSymbol) {
+internal fun SymbolToTransformer.add(from: Map<IrClassifierSymbol, IrFunctionSymbol>, to: IrSimpleFunctionSymbol) {
     from.forEach { _, func ->
         add(func, to)
     }
@@ -33,7 +33,7 @@ internal fun SymbolToTransformer.add(from: IrFunctionSymbol, to: (IrFunctionAcce
     put(from, to)
 }
 
-internal fun SymbolToTransformer.add(from: IrFunctionSymbol, to: IrFunctionSymbol, dispatchReceiverAsFirstArgument: Boolean = false) {
+internal fun SymbolToTransformer.add(from: IrFunctionSymbol, to: IrSimpleFunctionSymbol, dispatchReceiverAsFirstArgument: Boolean = false) {
     put(from) { call -> irCall(call, to, dispatchReceiverAsFirstArgument) }
 }
 
@@ -47,11 +47,11 @@ internal fun <K> MutableMap<K, (IrFunctionAccessExpression) -> IrExpression>.add
 
 internal typealias MemberToTransformer = HashMap<SimpleMemberKey, (IrFunctionAccessExpression) -> IrExpression>
 
-internal fun MemberToTransformer.add(type: IrType, name: Name, v: IrFunctionSymbol) {
+internal fun MemberToTransformer.add(type: IrType, name: Name, v: IrSimpleFunctionSymbol) {
     add(type, name) { irCall(it, v, receiversAsArguments = true) }
 }
 
-internal fun MemberToTransformer.add(type: IrType, name: Name, v: IrFunction) {
+internal fun MemberToTransformer.add(type: IrType, name: Name, v: IrSimpleFunction) {
     add(type, name, v.symbol)
 }
 
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/calls/NumberOperatorCallsTransformer.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/calls/NumberOperatorCallsTransformer.kt
index d7d3937a208..f049d25527f 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/calls/NumberOperatorCallsTransformer.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/calls/NumberOperatorCallsTransformer.kt
@@ -13,6 +13,7 @@ import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.IrFunctionAccessExpression
 import org.jetbrains.kotlin.ir.expressions.impl.IrCallImpl
 import org.jetbrains.kotlin.ir.symbols.IrFunctionSymbol
+import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
 import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.util.irCall
 import org.jetbrains.kotlin.name.Name
@@ -117,7 +118,7 @@ class NumberOperatorCallsTransformer(context: JsIrBackendContext) : CallsTransfo
 
     private fun irBinaryOp(
         call: IrFunctionAccessExpression,
-        intrinsic: IrFunctionSymbol,
+        intrinsic: IrSimpleFunctionSymbol,
         toInt32: Boolean = false
     ): IrExpression {
         val newCall = irCall(call, intrinsic, receiversAsArguments = true)
@@ -170,7 +171,7 @@ class NumberOperatorCallsTransformer(context: JsIrBackendContext) : CallsTransfo
     private fun transformDecrement(call: IrFunctionAccessExpression) =
         transformCrement(call, intrinsics.jsMinus)
 
-    private fun transformCrement(call: IrFunctionAccessExpression, correspondingBinaryOp: IrFunctionSymbol): IrExpression {
+    private fun transformCrement(call: IrFunctionAccessExpression, correspondingBinaryOp: IrSimpleFunctionSymbol): IrExpression {
         val operation = irCall(call, correspondingBinaryOp, receiversAsArguments = true).apply {
             putValueArgument(1, buildInt(1))
         }
@@ -262,7 +263,7 @@ class NumberOperatorCallsTransformer(context: JsIrBackendContext) : CallsTransfo
             }
         }
 
-    fun IrFunctionSymbol.call(vararg arguments: IrExpression) =
+    fun IrSimpleFunctionSymbol.call(vararg arguments: IrExpression) =
         JsIrBuilder.buildCall(this, owner.returnType).apply {
             for ((idx, arg) in arguments.withIndex()) {
                 putValueArgument(idx, arg)
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmBackendContext.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmBackendContext.kt
index 9f89eea03e5..471c2d3cd43 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmBackendContext.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmBackendContext.kt
@@ -101,7 +101,7 @@ class JvmBackendContext(
     internal val multifileFacadesToAdd = mutableMapOf<JvmClassName, MutableList<IrClass>>()
     val multifileFacadeForPart = mutableMapOf<IrClass, JvmClassName>()
     internal val multifileFacadeClassForPart = mutableMapOf<IrClass, IrClass>()
-    internal val multifileFacadeMemberToPartMember = mutableMapOf<IrFunction, IrFunction>()
+    internal val multifileFacadeMemberToPartMember = mutableMapOf<IrSimpleFunction, IrSimpleFunction>()
 
     internal val hiddenConstructors = mutableMapOf<IrConstructor, IrConstructor>()
 
@@ -117,7 +117,7 @@ class JvmBackendContext(
     val suspendFunctionOriginalToView = mutableMapOf<IrFunction, IrFunction>()
     val fakeContinuation: IrExpression = createFakeContinuation(this)
 
-    val staticDefaultStubs = mutableMapOf<IrFunctionSymbol, IrFunction>()
+    val staticDefaultStubs = mutableMapOf<IrSimpleFunctionSymbol, IrSimpleFunction>()
 
     val inlineClassReplacements = MemoizedInlineClassReplacements(state.functionsWithInlineClassReturnTypesMangled, irFactory)
 
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/ir/IrUtils.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/ir/IrUtils.kt
index de81ef14ebb..75c41e9c48b 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/ir/IrUtils.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/ir/IrUtils.kt
@@ -268,7 +268,11 @@ fun IrBody.replaceThisByStaticReference(
 fun createPlaceholderAnyNType(irBuiltIns: IrBuiltIns): IrType =
     irBuiltIns.anyNType
 
-fun createDelegatingCallWithPlaceholderTypeArguments(existingCall: IrCall, redirectTarget: IrFunction, irBuiltIns: IrBuiltIns): IrCall =
+fun createDelegatingCallWithPlaceholderTypeArguments(
+    existingCall: IrCall,
+    redirectTarget: IrSimpleFunction,
+    irBuiltIns: IrBuiltIns
+): IrCall =
     IrCallImpl(
         existingCall.startOffset,
         existingCall.endOffset,
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/GenerateMultifileFacades.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/GenerateMultifileFacades.kt
index 3d16fc99d9a..5abc2a21622 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/GenerateMultifileFacades.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/GenerateMultifileFacades.kt
@@ -47,7 +47,7 @@ internal val generateMultifileFacadesPhase = makeCustomPhase<JvmBackendContext,
     description = "Generate JvmMultifileClass facades, based on the information provided by FileClassLowering",
     prerequisite = setOf(fileClassPhase),
     op = { context, input ->
-        val functionDelegates = mutableMapOf<IrFunction, IrFunction>()
+        val functionDelegates = mutableMapOf<IrSimpleFunction, IrSimpleFunction>()
 
         // In -Xmultifile-parts-inherit mode, instead of generating "bridge" methods in the facade which call into parts,
         // we construct an inheritance chain such that all part members are present as fake overrides in the facade.
@@ -89,7 +89,7 @@ private fun generateMultifileFacades(
     module: ModuleDescriptor,
     context: JvmBackendContext,
     shouldGeneratePartHierarchy: Boolean,
-    functionDelegates: MutableMap<IrFunction, IrFunction>
+    functionDelegates: MutableMap<IrSimpleFunction, IrSimpleFunction>
 ): List<IrFile> =
     context.multifileFacadesToAdd.map { (jvmClassName, partClasses) ->
         val kotlinPackageFqName = partClasses.first().fqNameWhenAvailable!!.parent()
@@ -250,7 +250,7 @@ private fun IrSimpleFunction.createMultifileDelegateIfNeeded(
 }
 
 private class UpdateFunctionCallSites(
-    private val functionDelegates: MutableMap<IrFunction, IrFunction>
+    private val functionDelegates: MutableMap<IrSimpleFunction, IrSimpleFunction>
 ) : FileLoweringPass, IrElementTransformer<IrFunction?> {
     override fun lower(irFile: IrFile) {
         irFile.transformChildren(this, null)
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/InterfaceLowering.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/InterfaceLowering.kt
index 4281e66d038..62ee6f67331 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/InterfaceLowering.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/InterfaceLowering.kt
@@ -21,8 +21,8 @@ import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.IrFunctionReference
 import org.jetbrains.kotlin.ir.expressions.IrReturn
 import org.jetbrains.kotlin.ir.expressions.impl.*
-import org.jetbrains.kotlin.ir.symbols.IrFunctionSymbol
 import org.jetbrains.kotlin.ir.symbols.IrLocalDelegatedPropertySymbol
+import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
 import org.jetbrains.kotlin.ir.types.defaultType
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
@@ -36,7 +36,7 @@ import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
  */
 internal class InterfaceLowering(val context: JvmBackendContext) : IrElementTransformerVoid(), ClassLoweringPass {
 
-    private val removedFunctions = hashMapOf<IrFunctionSymbol, IrFunctionSymbol>()
+    private val removedFunctions = hashMapOf<IrSimpleFunctionSymbol, IrSimpleFunctionSymbol>()
 
     override fun lower(irClass: IrClass) {
         if (!irClass.isJvmInterface) return
@@ -199,7 +199,7 @@ internal class InterfaceLowering(val context: JvmBackendContext) : IrElementTran
 
     // Bridge from static to static method - simply fill the function arguments to the parameters.
     // By nature of the generation of both source and target of bridge, they line up.
-    private fun IrFunction.bridgeToStatic(callTarget: IrFunction) {
+    private fun IrFunction.bridgeToStatic(callTarget: IrSimpleFunction) {
         body = IrExpressionBodyImpl(IrCallImpl(startOffset, endOffset, returnType, callTarget.symbol).also { call ->
 
             callTarget.typeParameters.forEachIndexed { i, _ ->
@@ -214,7 +214,7 @@ internal class InterfaceLowering(val context: JvmBackendContext) : IrElementTran
 
     // Bridge from static DefaultImpl method to the interface method. Arguments need to
     // be shifted in presence of dispatch and extension receiver.
-    private fun IrFunction.bridgeViaAccessorTo(callTarget: IrFunction) {
+    private fun IrFunction.bridgeViaAccessorTo(callTarget: IrSimpleFunction) {
         body = IrExpressionBodyImpl(
             IrCallImpl(
                 startOffset,
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/JvmOverloadsAnnotationLowering.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/JvmOverloadsAnnotationLowering.kt
index 3b8121eaea3..70e7c30551a 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/JvmOverloadsAnnotationLowering.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/JvmOverloadsAnnotationLowering.kt
@@ -22,6 +22,7 @@ import org.jetbrains.kotlin.ir.types.defaultType
 import org.jetbrains.kotlin.ir.util.allTypeParameters
 import org.jetbrains.kotlin.ir.util.deepCopyWithSymbols
 import org.jetbrains.kotlin.ir.util.hasAnnotation
+import org.jetbrains.kotlin.ir.util.render
 import org.jetbrains.kotlin.resolve.jvm.annotations.JVM_OVERLOADS_FQ_NAME
 
 internal val jvmOverloadsAnnotationPhase = makeIrFilePhase(
@@ -55,10 +56,14 @@ private class JvmOverloadsAnnotationLowering(val context: JvmBackendContext) : C
     private fun generateWrapper(target: IrFunction, numDefaultParametersToExpect: Int): IrFunction {
         val wrapperIrFunction = context.irFactory.generateWrapperHeader(target, numDefaultParametersToExpect)
 
-        val call = if (target is IrConstructor)
-            IrDelegatingConstructorCallImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, context.irBuiltIns.unitType, target.symbol)
-        else
-            IrCallImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, target.returnType, target.symbol)
+        val call = when (target) {
+            is IrConstructor ->
+                IrDelegatingConstructorCallImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, context.irBuiltIns.unitType, target.symbol)
+            is IrSimpleFunction ->
+                IrCallImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, target.returnType, target.symbol)
+            else ->
+                error("unknown function kind: ${target.render()}")
+        }
         for (arg in wrapperIrFunction.allTypeParameters) {
             call.putTypeArgument(arg.index, arg.defaultType)
         }
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/JvmStandardLibraryBuiltInsLowering.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/JvmStandardLibraryBuiltInsLowering.kt
index bcd34f48449..5e4411b1fa8 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/JvmStandardLibraryBuiltInsLowering.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/JvmStandardLibraryBuiltInsLowering.kt
@@ -13,7 +13,7 @@ import org.jetbrains.kotlin.ir.declarations.IrFile
 import org.jetbrains.kotlin.ir.expressions.IrCall
 import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.impl.IrCallImpl
-import org.jetbrains.kotlin.ir.symbols.IrFunctionSymbol
+import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.util.fqNameForIrSerialization
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
@@ -59,7 +59,7 @@ class JvmStandardLibraryBuiltInsLowering(val context: JvmBackendContext) : FileL
 
     // Originals are so far only instance methods, and the replacements are
     // statics, so we copy dispatch receivers to a value argument if needed.
-    private fun IrCall.replaceWithCallTo(replacement: IrFunctionSymbol) =
+    private fun IrCall.replaceWithCallTo(replacement: IrSimpleFunctionSymbol) =
         IrCallImpl(
             startOffset,
             endOffset,
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/ResolveInlineCalls.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/ResolveInlineCalls.kt
index 652406e282f..b4b7ffd8835 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/ResolveInlineCalls.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/ResolveInlineCalls.kt
@@ -60,7 +60,7 @@ class ResolveInlineCalls(val context: JvmBackendContext) : IrElementTransformerV
         })
     }
 
-    private fun IrFunction.resolveMultiFileFacades(): IrFunction? =
+    private fun IrFunction.resolveMultiFileFacades(): IrSimpleFunction? =
         if (origin == JvmLoweredDeclarationOrigin.MULTIFILE_BRIDGE) {
             context.multifileFacadeMemberToPartMember[this]
         } else null
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/StaticDefaultFunctionLowering.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/StaticDefaultFunctionLowering.kt
index aa554bb5add..8d5db3483e5 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/StaticDefaultFunctionLowering.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/StaticDefaultFunctionLowering.kt
@@ -25,10 +25,7 @@ import org.jetbrains.kotlin.backend.common.phaser.makeIrFilePhase
 import org.jetbrains.kotlin.backend.common.phaser.then
 import org.jetbrains.kotlin.backend.jvm.JvmBackendContext
 import org.jetbrains.kotlin.ir.IrStatement
-import org.jetbrains.kotlin.ir.declarations.IrClass
-import org.jetbrains.kotlin.ir.declarations.IrDeclarationOrigin
-import org.jetbrains.kotlin.ir.declarations.IrFile
-import org.jetbrains.kotlin.ir.declarations.IrFunction
+import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.expressions.IrCall
 import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.IrReturn
@@ -63,7 +60,7 @@ private class StaticDefaultFunctionLowering(val context: JvmBackendContext) : Ir
         irClass.accept(this, null)
     }
 
-    override fun visitFunction(declaration: IrFunction): IrStatement = super.visitFunction(
+    override fun visitSimpleFunction(declaration: IrSimpleFunction): IrStatement = super.visitFunction(
         if (declaration.origin == IrDeclarationOrigin.FUNCTION_FOR_DEFAULT_PARAMETER && declaration.dispatchReceiverParameter != null)
             context.getStaticFunctionWithReceivers(declaration).also {
                 it.body = declaration.moveBodyTo(it)
@@ -106,7 +103,7 @@ private class StaticDefaultCallLowering(
     }
 }
 
-private fun JvmBackendContext.getStaticFunctionWithReceivers(function: IrFunction) =
+private fun JvmBackendContext.getStaticFunctionWithReceivers(function: IrSimpleFunction) =
     staticDefaultStubs.getOrPut(function.symbol) {
         irFactory.createStaticFunctionWithReceivers(function.parent, function.name, function)
     }
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/SyntheticAccessorLowering.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/SyntheticAccessorLowering.kt
index 934d94c6185..5ff1b7cc1dd 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/SyntheticAccessorLowering.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/SyntheticAccessorLowering.kt
@@ -313,7 +313,7 @@ internal class SyntheticAccessorLowering(val context: JvmBackendContext) : IrEle
         }
     }
 
-    private fun createSimpleFunctionCall(accessor: IrFunction, targetSymbol: IrFunctionSymbol, superQualifierSymbol: IrClassSymbol?) =
+    private fun createSimpleFunctionCall(accessor: IrFunction, targetSymbol: IrSimpleFunctionSymbol, superQualifierSymbol: IrClassSymbol?) =
         IrCallImpl(
             UNDEFINED_OFFSET, UNDEFINED_OFFSET,
             accessor.returnType,
@@ -410,7 +410,7 @@ internal class SyntheticAccessorLowering(val context: JvmBackendContext) : IrEle
             is IrCall -> IrCallImpl(
                 oldExpression.startOffset, oldExpression.endOffset,
                 oldExpression.type,
-                accessorSymbol, oldExpression.typeArgumentsCount,
+                accessorSymbol as IrSimpleFunctionSymbol, oldExpression.typeArgumentsCount,
                 oldExpression.origin
             )
             is IrDelegatingConstructorCall -> IrDelegatingConstructorCallImpl(
@@ -447,7 +447,7 @@ internal class SyntheticAccessorLowering(val context: JvmBackendContext) : IrEle
 
     private fun modifyGetterExpression(
         oldExpression: IrGetField,
-        accessorSymbol: IrFunctionSymbol
+        accessorSymbol: IrSimpleFunctionSymbol
     ): IrCall {
         val call = IrCallImpl(
             oldExpression.startOffset, oldExpression.endOffset,
@@ -463,7 +463,7 @@ internal class SyntheticAccessorLowering(val context: JvmBackendContext) : IrEle
 
     private fun modifySetterExpression(
         oldExpression: IrSetField,
-        accessorSymbol: IrFunctionSymbol
+        accessorSymbol: IrSimpleFunctionSymbol
     ): IrCall {
         val call = IrCallImpl(
             oldExpression.startOffset, oldExpression.endOffset,
diff --git a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/AssignmentGenerator.kt b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/AssignmentGenerator.kt
index ee952ac3c5e..fa7f1e62144 100644
--- a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/AssignmentGenerator.kt
+++ b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/AssignmentGenerator.kt
@@ -28,7 +28,6 @@ import org.jetbrains.kotlin.ir.builders.irGet
 import org.jetbrains.kotlin.ir.builders.irTemporary
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.IrDynamicOperatorExpressionImpl
-import org.jetbrains.kotlin.ir.util.referenceFunction
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.endOffset
@@ -317,8 +316,8 @@ class AssignmentGenerator(statementGenerator: StatementGenerator) : StatementGen
         val getterDescriptor = unwrappedPropertyDescriptor.unwrappedGetMethod
         val setterDescriptor = unwrappedPropertyDescriptor.unwrappedSetMethod
 
-        val getterSymbol = getterDescriptor?.let { context.symbolTable.referenceFunction(it.original) }
-        val setterSymbol = setterDescriptor?.let { context.symbolTable.referenceFunction(it.original) }
+        val getterSymbol = getterDescriptor?.let { context.symbolTable.referenceSimpleFunction(it.original) }
+        val setterSymbol = setterDescriptor?.let { context.symbolTable.referenceSimpleFunction(it.original) }
 
         val propertyIrType = descriptor.type.toIrType()
         return if (getterSymbol != null || setterSymbol != null) {
diff --git a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/CallGenerator.kt b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/CallGenerator.kt
index 66391cbe59b..f1897139269 100644
--- a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/CallGenerator.kt
+++ b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/CallGenerator.kt
@@ -23,7 +23,6 @@ import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.types.IrDynamicType
 import org.jetbrains.kotlin.ir.types.IrType
-import org.jetbrains.kotlin.ir.util.referenceFunction
 import org.jetbrains.kotlin.ir.util.render
 import org.jetbrains.kotlin.psi.KtElement
 import org.jetbrains.kotlin.psi.psiUtil.endOffset
@@ -122,7 +121,7 @@ class CallGenerator(statementGenerator: StatementGenerator) : StatementGenerator
     ) =
         if (descriptor is LocalVariableDescriptor && descriptor.isDelegated) {
             val getterDescriptor = descriptor.getter!!
-            val getterSymbol = context.symbolTable.referenceFunction(getterDescriptor.original)
+            val getterSymbol = context.symbolTable.referenceSimpleFunction(getterDescriptor.original)
             IrCallImpl(
                 startOffset, endOffset, descriptor.type.toIrType(), getterSymbol, origin ?: IrStatementOrigin.GET_LOCAL_PROPERTY
             ).apply {
@@ -207,7 +206,7 @@ class CallGenerator(statementGenerator: StatementGenerator) : StatementGenerator
                         dispatchReceiver
                     )
                 } else {
-                    val getterSymbol = context.symbolTable.referenceFunction(getMethodDescriptor.original)
+                    val getterSymbol = context.symbolTable.referenceSimpleFunction(getMethodDescriptor.original)
                     IrCallImpl(
                         startOffset, endOffset,
                         irType,
@@ -333,7 +332,7 @@ class CallGenerator(statementGenerator: StatementGenerator) : StatementGenerator
                         )
                 }
             } else {
-                val originalSymbol = context.symbolTable.referenceFunction(functionDescriptor.original)
+                val originalSymbol = context.symbolTable.referenceSimpleFunction(functionDescriptor.original)
                 IrCallImpl(
                     startOffset, endOffset,
                     irType,
diff --git a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ClassGenerator.kt b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ClassGenerator.kt
index fc6a3546e0c..d532b839029 100644
--- a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ClassGenerator.kt
+++ b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ClassGenerator.kt
@@ -32,7 +32,6 @@ import org.jetbrains.kotlin.ir.expressions.typeParametersCount
 import org.jetbrains.kotlin.ir.util.createIrClassFromDescriptor
 import org.jetbrains.kotlin.ir.util.declareSimpleFunctionWithOverrides
 import org.jetbrains.kotlin.ir.util.properties
-import org.jetbrains.kotlin.ir.util.referenceFunction
 import org.jetbrains.kotlin.psi.KtClassOrObject
 import org.jetbrains.kotlin.psi.KtDelegatedSuperTypeEntry
 import org.jetbrains.kotlin.psi.KtEnumEntry
@@ -332,7 +331,7 @@ class ClassGenerator(
         val substitutedDelegateTo = substituteDelegateToDescriptor(delegatedDescriptor, delegateToDescriptor)
         val returnType = substitutedDelegateTo.returnType!!
 
-        val delegateToSymbol = context.symbolTable.referenceFunction(delegateToDescriptor.original)
+        val delegateToSymbol = context.symbolTable.referenceSimpleFunction(delegateToDescriptor.original)
 
         val irCall = IrCallImpl(
             startOffset, endOffset,
diff --git a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/OperatorExpressionGenerator.kt b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/OperatorExpressionGenerator.kt
index 74e931dde81..284ee3a6280 100644
--- a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/OperatorExpressionGenerator.kt
+++ b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/OperatorExpressionGenerator.kt
@@ -29,7 +29,6 @@ import org.jetbrains.kotlin.ir.types.classifierOrFail
 import org.jetbrains.kotlin.ir.types.classifierOrNull
 import org.jetbrains.kotlin.ir.types.impl.originalKotlinType
 import org.jetbrains.kotlin.ir.types.makeNotNull
-import org.jetbrains.kotlin.ir.util.referenceFunction
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.*
@@ -413,7 +412,7 @@ class OperatorExpressionGenerator(statementGenerator: StatementGenerator) : Stat
         functionDescriptor: FunctionDescriptor,
         receiver: IrExpression
     ): IrExpression {
-        val originalSymbol = context.symbolTable.referenceFunction(functionDescriptor.original)
+        val originalSymbol = context.symbolTable.referenceSimpleFunction(functionDescriptor.original)
         return IrCallImpl(
             startOffset,
             endOffset,
diff --git a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ReflectionReferencesGenerator.kt b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ReflectionReferencesGenerator.kt
index 8fd850f9875..2f5cf512f99 100644
--- a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ReflectionReferencesGenerator.kt
+++ b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ReflectionReferencesGenerator.kt
@@ -32,6 +32,7 @@ import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.symbols.IrConstructorSymbol
 import org.jetbrains.kotlin.ir.symbols.IrFunctionSymbol
+import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
 import org.jetbrains.kotlin.ir.symbols.IrVariableSymbol
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.name.Name
@@ -197,18 +198,13 @@ class ReflectionReferencesGenerator(statementGenerator: StatementGenerator) : St
 
         val irType = resolvedDescriptor.returnType!!.toIrType()
 
-        val irCall =
-            if (resolvedDescriptor is ConstructorDescriptor)
-                IrConstructorCallImpl.fromSymbolDescriptor(
-                    startOffset, endOffset, irType,
-                    adapteeSymbol as IrConstructorSymbol
-                )
-            else
-                IrCallImpl(
-                    startOffset, endOffset, irType,
-                    adapteeSymbol,
-                    origin = null, superQualifierSymbol = null
-                )
+        val irCall = when (adapteeSymbol) {
+            is IrConstructorSymbol ->
+                IrConstructorCallImpl.fromSymbolDescriptor(startOffset, endOffset, irType, adapteeSymbol)
+            is IrSimpleFunctionSymbol ->
+                IrCallImpl(startOffset, endOffset, irType, adapteeSymbol, origin = null, superQualifierSymbol = null)
+            else -> error("Unknown symbol kind $adapteeSymbol")
+        }
 
         val hasBoundDispatchReceiver = resolvedCall.dispatchReceiver != null && resolvedCall.dispatchReceiver !is TransientReceiver
         val hasBoundExtensionReceiver = resolvedCall.extensionReceiver != null && resolvedCall.extensionReceiver !is TransientReceiver
diff --git a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/intermediate/PropertyLValue.kt b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/intermediate/PropertyLValue.kt
index 818e1d34791..983bc792550 100644
--- a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/intermediate/PropertyLValue.kt
+++ b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/intermediate/PropertyLValue.kt
@@ -25,7 +25,7 @@ import org.jetbrains.kotlin.ir.expressions.IrStatementOrigin
 import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
 import org.jetbrains.kotlin.ir.symbols.IrFieldSymbol
-import org.jetbrains.kotlin.ir.symbols.IrFunctionSymbol
+import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.psi2ir.generators.GeneratorContext
 
@@ -126,9 +126,9 @@ class AccessorPropertyLValue(
     endOffset: Int,
     origin: IrStatementOrigin?,
     type: IrType,
-    val getter: IrFunctionSymbol?,
+    val getter: IrSimpleFunctionSymbol?,
     val getterDescriptor: FunctionDescriptor?,
-    val setter: IrFunctionSymbol?,
+    val setter: IrSimpleFunctionSymbol?,
     val setterDescriptor: FunctionDescriptor?,
     val typeArguments: List<IrType>?,
     callReceiver: CallReceiver,
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/IrCall.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/IrCall.kt
index 73f2b18f043..e1c45dabf72 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/IrCall.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/IrCall.kt
@@ -17,10 +17,12 @@
 package org.jetbrains.kotlin.ir.expressions
 
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
+import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
 
 abstract class IrCall(
     typeArgumentsCount: Int,
     valueArgumentsCount: Int,
 ) : IrFunctionAccessExpression(typeArgumentsCount, valueArgumentsCount) {
+    override abstract val symbol: IrSimpleFunctionSymbol
     abstract val superQualifierSymbol: IrClassSymbol?
 }
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/impl/IrCallImpl.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/impl/IrCallImpl.kt
index a245d3c28fc..b7fe16e2846 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/impl/IrCallImpl.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/impl/IrCallImpl.kt
@@ -22,7 +22,7 @@ import org.jetbrains.kotlin.ir.expressions.IrStatementOrigin
 import org.jetbrains.kotlin.ir.expressions.typeParametersCount
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
 import org.jetbrains.kotlin.ir.symbols.IrConstructorSymbol
-import org.jetbrains.kotlin.ir.symbols.IrFunctionSymbol
+import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.util.render
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitor
@@ -31,7 +31,7 @@ class IrCallImpl(
     override val startOffset: Int,
     override val endOffset: Int,
     override val type: IrType,
-    override val symbol: IrFunctionSymbol,
+    override val symbol: IrSimpleFunctionSymbol,
     typeArgumentsCount: Int,
     valueArgumentsCount: Int,
     override val origin: IrStatementOrigin? = null,
@@ -48,7 +48,7 @@ class IrCallImpl(
         startOffset: Int,
         endOffset: Int,
         type: IrType,
-        symbol: IrFunctionSymbol,
+        symbol: IrSimpleFunctionSymbol,
         origin: IrStatementOrigin? = null,
         superQualifierSymbol: IrClassSymbol? = null
     ) : this(
@@ -61,7 +61,7 @@ class IrCallImpl(
         startOffset: Int,
         endOffset: Int,
         type: IrType,
-        symbol: IrFunctionSymbol,
+        symbol: IrSimpleFunctionSymbol,
         typeArgumentsCount: Int,
         origin: IrStatementOrigin? = null,
         superQualifierSymbol: IrClassSymbol? = null
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DeepCopyIrTreeWithSymbols.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DeepCopyIrTreeWithSymbols.kt
index c3dee986f00..7a0f34bae85 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DeepCopyIrTreeWithSymbols.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DeepCopyIrTreeWithSymbols.kt
@@ -519,7 +519,7 @@ open class DeepCopyIrTreeWithSymbols(
     }
 
     private fun shallowCopyCall(expression: IrCall): IrCall {
-        val newCallee = symbolRemapper.getReferencedFunction(expression.symbol)
+        val newCallee = symbolRemapper.getReferencedSimpleFunction(expression.symbol)
         return IrCallImpl(
             expression.startOffset, expression.endOffset,
             expression.type.remapType(),
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt
index 8fb65e47496..2f5cdabc4cb 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt
@@ -411,7 +411,7 @@ fun irConstructorCall(
 
 fun irCall(
     call: IrFunctionAccessExpression,
-    newFunction: IrFunction,
+    newFunction: IrSimpleFunction,
     receiversAsArguments: Boolean = false,
     argumentsAsReceivers: Boolean = false,
     newSuperQualifierSymbol: IrClassSymbol? = null
@@ -426,7 +426,7 @@ fun irCall(
 
 fun irCall(
     call: IrFunctionAccessExpression,
-    newSymbol: IrFunctionSymbol,
+    newSymbol: IrSimpleFunctionSymbol,
     receiversAsArguments: Boolean = false,
     argumentsAsReceivers: Boolean = false,
     newSuperQualifierSymbol: IrClassSymbol? = null
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrFileDeserializer.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrFileDeserializer.kt
index c29ef995e4c..d11ab6ae8fb 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrFileDeserializer.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrFileDeserializer.kt
@@ -379,7 +379,7 @@ abstract class IrFileDeserializer(
     }
 
     private fun deserializeCall(proto: ProtoCall, start: Int, end: Int, type: IrType): IrCall {
-        val symbol = deserializeIrSymbolAndRemap(proto.symbol) as IrFunctionSymbol
+        val symbol = deserializeIrSymbolAndRemap(proto.symbol) as IrSimpleFunctionSymbol
 
         val superSymbol = if (proto.hasSuper()) {
             deserializeIrSymbolAndRemap(proto.`super`) as IrClassSymbol
diff --git a/plugins/android-extensions/android-extensions-compiler/src/org/jetbrains/kotlin/android/parcel/ir/ParcelableIrTransformer.kt b/plugins/android-extensions/android-extensions-compiler/src/org/jetbrains/kotlin/android/parcel/ir/ParcelableIrTransformer.kt
index 1e57a25bcd2..bbce17eb1d3 100644
--- a/plugins/android-extensions/android-extensions-compiler/src/org/jetbrains/kotlin/android/parcel/ir/ParcelableIrTransformer.kt
+++ b/plugins/android-extensions/android-extensions-compiler/src/org/jetbrains/kotlin/android/parcel/ir/ParcelableIrTransformer.kt
@@ -28,7 +28,6 @@ import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.IrFunctionReference
 import org.jetbrains.kotlin.ir.expressions.impl.IrCallImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrFunctionReferenceImpl
-import org.jetbrains.kotlin.ir.symbols.IrFunctionSymbol
 import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
 import org.jetbrains.kotlin.ir.symbols.IrSymbol
 import org.jetbrains.kotlin.ir.types.*
@@ -51,7 +50,7 @@ class ParcelableIrTransformer(private val context: IrPluginContext, private val
     private fun IrPluginContext.createIrBuilder(symbol: IrSymbol) =
         DeclarationIrBuilder(this, symbol, symbol.owner.startOffset, symbol.owner.endOffset)
 
-    private val symbolMap = mutableMapOf<IrFunctionSymbol, IrFunctionSymbol>()
+    private val symbolMap = mutableMapOf<IrSimpleFunctionSymbol, IrSimpleFunctionSymbol>()
 
     private val irFactory: IrFactory = IrFactoryImpl
 
@@ -91,7 +90,7 @@ class ParcelableIrTransformer(private val context: IrPluginContext, private val
             override fun visitSimpleFunction(declaration: IrSimpleFunction): IrStatement {
                 // Remap overridden symbols, otherwise the code might break in BridgeLowering
                 declaration.overriddenSymbols = declaration.overriddenSymbols.map { symbol ->
-                    (symbolMap[symbol] ?: symbol) as IrSimpleFunctionSymbol
+                    symbolMap[symbol] ?: symbol
                 }
                 return super.visitSimpleFunction(declaration)
             }