From d31efaa7ac21e22cc79437528024a90de7a934ef Mon Sep 17 00:00:00 2001
From: Dmitry Petrov <dmitry.petrov@jetbrains.com>
Date: Wed, 4 Oct 2017 11:59:48 +0300
Subject: [PATCH] Don't analyze method in RNCE if there're no optimizable
 instructions

---
 .../nullCheck/RedundantNullCheckMethodTransformer.kt      | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/nullCheck/RedundantNullCheckMethodTransformer.kt b/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/nullCheck/RedundantNullCheckMethodTransformer.kt
index 50852bb8e56..9460548a0ad 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/nullCheck/RedundantNullCheckMethodTransformer.kt
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/nullCheck/RedundantNullCheckMethodTransformer.kt
@@ -46,6 +46,8 @@ class RedundantNullCheckMethodTransformer : MethodTransformer() {
         private var changes = false
 
         fun run(): Boolean {
+            if (methodNode.instructions.toArray().none { it.isOptimizable() }) return false
+
             val checkedReferenceTypes = analyzeTypesAndRemoveDeadCode()
             eliminateRedundantChecks(checkedReferenceTypes)
 
@@ -120,6 +122,12 @@ class RedundantNullCheckMethodTransformer : MethodTransformer() {
             return nullabilityMap
         }
 
+        private fun AbstractInsnNode.isOptimizable() =
+                opcode == Opcodes.IFNULL ||
+                opcode == Opcodes.IFNONNULL ||
+                opcode == Opcodes.INSTANCEOF ||
+                isCheckExpressionValueIsNotNull()
+
         private fun transformTrivialChecks(nullabilityMap: Map<AbstractInsnNode, StrictBasicValue>) {
             for ((insn, value) in nullabilityMap) {
                 val nullability = value.getNullability()