diff --git a/compiler/ir/backend.jvm/codegen/src/org/jetbrains/kotlin/backend/jvm/codegen/ExpressionCodegen.kt b/compiler/ir/backend.jvm/codegen/src/org/jetbrains/kotlin/backend/jvm/codegen/ExpressionCodegen.kt
index 7c9ac9e4312..3a4cfff91a1 100644
--- a/compiler/ir/backend.jvm/codegen/src/org/jetbrains/kotlin/backend/jvm/codegen/ExpressionCodegen.kt
+++ b/compiler/ir/backend.jvm/codegen/src/org/jetbrains/kotlin/backend/jvm/codegen/ExpressionCodegen.kt
@@ -1601,7 +1601,7 @@ class ExpressionCodegen(
                 //avoid ambiguity with type constructor type parameters
                 emptyMap()
             } else typeArgumentContainer.typeParameters.associate {
-                it.symbol to element.getTypeArgumentOrDefault(it)
+                it.symbol to (element.getTypeArgument(it.index) ?: it.defaultType)
             }
 
         val mappings = TypeParameterMappings(typeMapper.typeSystem, typeArguments, allReified = false, typeMapper::mapTypeParameter)
diff --git a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ArgumentsGenerationUtils.kt b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ArgumentsGenerationUtils.kt
index 5caff5a989d..36db9b192fc 100644
--- a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ArgumentsGenerationUtils.kt
+++ b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ArgumentsGenerationUtils.kt
@@ -862,3 +862,13 @@ internal fun unwrapCallableDescriptorAndTypeArguments(resolvedCall: ResolvedCall
 
     return CallBuilder(resolvedCall, substitutedUnwrappedDescriptor, unwrappedTypeArguments)
 }
+
+internal inline fun IrMemberAccessExpression<*>.putTypeArguments(
+    typeArguments: Map<TypeParameterDescriptor, KotlinType>?,
+    toIrType: (KotlinType) -> IrType
+) {
+    if (typeArguments == null) return
+    for ((typeParameter, typeArgument) in typeArguments) {
+        putTypeArgument(typeParameter.index, toIrType(typeArgument))
+    }
+}
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 275d14974c8..67f0e2360c0 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
@@ -28,7 +28,6 @@ import org.jetbrains.kotlin.ir.expressions.impl.IrCallImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrGetFieldImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrGetValueImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrReturnImpl
-import org.jetbrains.kotlin.ir.expressions.putTypeArguments
 import org.jetbrains.kotlin.ir.expressions.typeParametersCount
 import org.jetbrains.kotlin.ir.symbols.impl.IrFieldSymbolImpl
 import org.jetbrains.kotlin.ir.types.IrSimpleType
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/IrMemberAccessExpression.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/IrMemberAccessExpression.kt
index 8127518109b..ebe361e66ad 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/IrMemberAccessExpression.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/IrMemberAccessExpression.kt
@@ -8,14 +8,10 @@ package org.jetbrains.kotlin.ir.expressions
 import org.jetbrains.kotlin.descriptors.CallableDescriptor
 import org.jetbrains.kotlin.descriptors.PropertyAccessorDescriptor
 import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
-import org.jetbrains.kotlin.descriptors.ValueParameterDescriptor
-import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
 import org.jetbrains.kotlin.ir.declarations.IrFunction
-import org.jetbrains.kotlin.ir.declarations.IrTypeParameter
 import org.jetbrains.kotlin.ir.declarations.IrValueParameter
 import org.jetbrains.kotlin.ir.symbols.IrSymbol
 import org.jetbrains.kotlin.ir.types.IrType
-import org.jetbrains.kotlin.ir.types.defaultType
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformer
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitor
 import org.jetbrains.kotlin.types.KotlinType
@@ -92,9 +88,6 @@ internal fun IrMemberAccessExpression<*>.throwNoSuchArgumentSlotException(kind:
     )
 }
 
-fun IrMemberAccessExpression<*>.getTypeArgument(typeParameterDescriptor: TypeParameterDescriptor): IrType? =
-    getTypeArgument(typeParameterDescriptor.index)
-
 fun IrMemberAccessExpression<*>.copyTypeArgumentsFrom(other: IrMemberAccessExpression<*>, shift: Int = 0) {
     assert(typeArgumentsCount == other.typeArgumentsCount + shift) {
         "Mismatching type arguments: $typeArgumentsCount vs ${other.typeArgumentsCount} + $shift"
@@ -104,16 +97,6 @@ fun IrMemberAccessExpression<*>.copyTypeArgumentsFrom(other: IrMemberAccessExpre
     }
 }
 
-inline fun IrMemberAccessExpression<*>.putTypeArguments(
-    typeArguments: Map<TypeParameterDescriptor, KotlinType>?,
-    toIrType: (KotlinType) -> IrType
-) {
-    if (typeArguments == null) return
-    for ((typeParameter, typeArgument) in typeArguments) {
-        putTypeArgument(typeParameter.index, toIrType(typeArgument))
-    }
-}
-
 val CallableDescriptor.typeParametersCount: Int
     get() =
         when (this) {
@@ -121,43 +104,6 @@ val CallableDescriptor.typeParametersCount: Int
             else -> typeParameters.size
         }
 
-fun IrMemberAccessExpression<*>.getTypeArgumentOrDefault(irTypeParameter: IrTypeParameter) =
-    getTypeArgument(irTypeParameter.index) ?: irTypeParameter.defaultType
-
-fun IrMemberAccessExpression<*>.getValueArgument(valueParameterDescriptor: ValueParameterDescriptor) =
-    getValueArgument(valueParameterDescriptor.index)
-
-fun IrMemberAccessExpression<*>.putValueArgument(valueParameterDescriptor: ValueParameterDescriptor, valueArgument: IrExpression?) {
-    putValueArgument(valueParameterDescriptor.index, valueArgument)
-}
-
-@ObsoleteDescriptorBasedAPI
-inline fun <T : IrMemberAccessExpression<*>> T.mapTypeParameters(transform: (TypeParameterDescriptor) -> IrType) : T =
-    apply {
-        val descriptor = symbol.descriptor as CallableDescriptor
-        descriptor.typeParameters.forEach {
-            putTypeArgument(it.index, transform(it))
-        }
-    }
-
-@ObsoleteDescriptorBasedAPI
-inline fun <T : IrMemberAccessExpression<*>> T.mapValueParameters(transform: (ValueParameterDescriptor) -> IrExpression?): T =
-    apply {
-        val descriptor = symbol.descriptor as CallableDescriptor
-        descriptor.valueParameters.forEach {
-            putValueArgument(it.index, transform(it))
-        }
-    }
-
-@ObsoleteDescriptorBasedAPI
-inline fun <T : IrMemberAccessExpression<*>> T.mapValueParametersIndexed(transform: (Int, ValueParameterDescriptor) -> IrExpression?): T =
-    apply {
-        val descriptor = symbol.descriptor as CallableDescriptor
-        descriptor.valueParameters.forEach {
-            putValueArgument(it.index, transform(it.index, it))
-        }
-    }
-
 fun IrMemberAccessExpression<*>.putArgument(callee: IrFunction, parameter: IrValueParameter, argument: IrExpression) =
     when (parameter) {
         callee.dispatchReceiverParameter -> dispatchReceiver = argument
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DataClassMembersGenerator.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DataClassMembersGenerator.kt
index 73bd871edbd..a3e1df7fe63 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DataClassMembersGenerator.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DataClassMembersGenerator.kt
@@ -117,10 +117,11 @@ abstract class DataClassMembersGenerator(
                     irClass.defaultType,
                     constructedClass = irClass
                 ).apply {
-                    mapTypeParameters(::transform)
-                    mapValueParameters {
-                        val irValueParameter = irFunction.valueParameters[it.index]
-                        irGet(irValueParameter.type, irValueParameter.symbol)
+                    for ((i, typeParameter) in constructorSymbol.descriptor.typeParameters.withIndex()) {
+                        putTypeArgument(i, transform(typeParameter))
+                    }
+                    for ((i, valueParameter) in irFunction.valueParameters.withIndex()) {
+                        putValueArgument(i, irGet(valueParameter.type, valueParameter.symbol))
                     }
                 }
             )
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 597191d899d..db86162e52b 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
@@ -82,7 +82,7 @@ fun IrFunctionAccessExpression.getArgumentsWithSymbols(): List<Pair<IrValueParam
     }
 
     irFunction.valueParameters.forEach {
-        val arg = getValueArgument(it.descriptor as ValueParameterDescriptor)
+        val arg = getValueArgument((it.descriptor as ValueParameterDescriptor).index)
         if (arg != null) {
             res += (it.symbol to arg)
         }
diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IntrinsicGenerator.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IntrinsicGenerator.kt
index 0fe8796cb6b..c866f28cb1a 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IntrinsicGenerator.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IntrinsicGenerator.kt
@@ -414,7 +414,7 @@ internal class IntrinsicGenerator(private val environment: IntrinsicGeneratorEnv
 
     private fun FunctionGenerationContext.emitCreateUninitializedInstance(callSite: IrCall, resultSlot: LLVMValueRef?): LLVMValueRef {
         val typeParameterT = context.ir.symbols.createUninitializedInstance.descriptor.typeParameters[0]
-        val enumClass = callSite.getTypeArgument(typeParameterT)!!
+        val enumClass = callSite.getTypeArgument(typeParameterT.index)!!
         val enumIrClass = enumClass.getClass()!!
         return allocInstance(enumIrClass, environment.calculateLifetime(callSite), resultSlot)
     }