diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/intrinsics/IntrinsicsMap.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/intrinsics/IntrinsicsMap.java
deleted file mode 100644
index d949e9ffe73..00000000000
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/intrinsics/IntrinsicsMap.java
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- * Copyright 2010-2015 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.jetbrains.kotlin.codegen.intrinsics;
-
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-import org.jetbrains.kotlin.descriptors.*;
-import org.jetbrains.kotlin.name.FqName;
-import org.jetbrains.kotlin.name.FqNameUnsafe;
-import org.jetbrains.kotlin.resolve.DescriptorUtils;
-
-import java.util.HashMap;
-import java.util.Map;
-
-class IntrinsicsMap {
-    private static final class Key {
-        private final FqNameUnsafe owner;
-        private final FqNameUnsafe receiverParameter;
-        private final String name;
-        private final int valueParameterCount;
-
-        private Key(@NotNull FqNameUnsafe owner, @Nullable FqNameUnsafe receiverParameter, @NotNull String name, int valueParameterCount) {
-            this.owner = owner;
-            this.receiverParameter = receiverParameter;
-            this.name = name;
-            this.valueParameterCount = valueParameterCount;
-        }
-
-        @Override
-        public boolean equals(Object o) {
-            if (this == o) return true;
-            if (o == null || getClass() != o.getClass()) return false;
-
-            Key key = (Key) o;
-
-            if (valueParameterCount != key.valueParameterCount) return false;
-            if (!name.equals(key.name)) return false;
-            if (!owner.equals(key.owner)) return false;
-            if (receiverParameter == null ? key.receiverParameter != null : !receiverParameter.equals(key.receiverParameter)) return false;
-
-            return true;
-        }
-
-        @Override
-        public int hashCode() {
-            int result = owner.hashCode();
-            result = 31 * result + name.hashCode();
-            result = 31 * result + valueParameterCount;
-            result = 31 * result + (receiverParameter != null ? receiverParameter.hashCode() : 0);
-            return result;
-        }
-    }
-
-    private static int valueParameterCountForKey(@NotNull CallableMemberDescriptor member) {
-        if (member instanceof PropertyDescriptor) {
-            return -1;
-        }
-        else {
-            return member.getValueParameters().size();
-        }
-    }
-
-    private final Map<Key, IntrinsicMethod> intrinsicsMap = new HashMap<>();
-
-
-    /**
-     * @param valueParameterCount -1 for property
-     */
-    public void registerIntrinsic(
-            @NotNull FqName owner,
-            @Nullable FqNameUnsafe receiverParameter,
-            @NotNull String name,
-            int valueParameterCount,
-            @NotNull IntrinsicMethod impl
-    ) {
-        intrinsicsMap.put(new Key(owner.toUnsafe(), receiverParameter, name, valueParameterCount), impl);
-    }
-
-    @Nullable
-    public IntrinsicMethod getIntrinsic(@NotNull CallableMemberDescriptor descriptor) {
-        Key key = new Key(
-                DescriptorUtils.getFqName(descriptor.getContainingDeclaration()),
-                getReceiverParameterFqName(descriptor),
-                descriptor.getName().asString(),
-                valueParameterCountForKey(descriptor)
-        );
-        return intrinsicsMap.get(key);
-    }
-
-    @Nullable
-    private static FqNameUnsafe getReceiverParameterFqName(@NotNull CallableMemberDescriptor descriptor) {
-        ReceiverParameterDescriptor receiverParameter = descriptor.getExtensionReceiverParameter();
-        if (receiverParameter == null) return null;
-
-        ClassifierDescriptor classifier = receiverParameter.getType().getConstructor().getDeclarationDescriptor();
-        if (classifier == null) return null;
-
-        if (classifier instanceof TypeParameterDescriptor) {
-            return IntrinsicMethods.RECEIVER_PARAMETER_FQ_NAME;
-        }
-
-        return DescriptorUtils.getFqName(classifier);
-    }
-}
diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/intrinsics/IntrinsicsMap.kt b/compiler/backend/src/org/jetbrains/kotlin/codegen/intrinsics/IntrinsicsMap.kt
new file mode 100644
index 00000000000..271df50e1a9
--- /dev/null
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/intrinsics/IntrinsicsMap.kt
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.codegen.intrinsics
+
+import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor
+import org.jetbrains.kotlin.descriptors.PropertyDescriptor
+import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.FqNameUnsafe
+import org.jetbrains.kotlin.resolve.DescriptorUtils
+import java.util.*
+
+internal class IntrinsicsMap {
+
+    private val intrinsicsMap = HashMap<Key, IntrinsicMethod>()
+
+    private data class Key(
+        private val owner: FqNameUnsafe,
+        private val receiverParameter: FqNameUnsafe?,
+        private val name: String,
+        private val valueParameterCount: Int
+    )
+
+    private fun valueParameterCountForKey(member: CallableMemberDescriptor): Int =
+        if (member is PropertyDescriptor)
+            -1
+        else
+            member.valueParameters.size
+
+
+    /**
+     * @param valueParameterCount -1 for property
+     */
+    fun registerIntrinsic(
+        owner: FqName,
+        receiverParameter: FqNameUnsafe?,
+        name: String,
+        valueParameterCount: Int,
+        impl: IntrinsicMethod
+    ) {
+        intrinsicsMap[Key(owner.toUnsafe(), receiverParameter, name, valueParameterCount)] = impl
+    }
+
+    fun getIntrinsic(descriptor: CallableMemberDescriptor): IntrinsicMethod? =
+        intrinsicsMap[Key(
+            DescriptorUtils.getFqName(descriptor.containingDeclaration),
+            getReceiverParameterFqName(descriptor),
+            descriptor.name.asString(),
+            valueParameterCountForKey(descriptor)
+        )]
+
+    private fun getReceiverParameterFqName(descriptor: CallableMemberDescriptor): FqNameUnsafe? {
+        val receiverParameter = descriptor.extensionReceiverParameter ?: return null
+        val classifier = receiverParameter.type.constructor.declarationDescriptor ?: return null
+
+        return if (classifier is TypeParameterDescriptor)
+            IntrinsicMethods.RECEIVER_PARAMETER_FQ_NAME
+        else
+            DescriptorUtils.getFqName(classifier)
+    }
+}