From fe71435104d87096b9097024abfc6c07a1c4f5d9 Mon Sep 17 00:00:00 2001
From: Dmitry Petrov <dmitry.petrov@jetbrains.com>
Date: Sat, 10 Jul 2021 20:37:30 +0300
Subject: [PATCH] JVM KT-47613 traverse nodes backwards in backward analysis

---
 .../kotlin/codegen/optimization/common/backwardAnalysis.kt   | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/common/backwardAnalysis.kt b/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/common/backwardAnalysis.kt
index e3ba541c3de..bf5ccbc5a15 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/common/backwardAnalysis.kt
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/common/backwardAnalysis.kt
@@ -38,13 +38,12 @@ fun <F : VarFrame<F>> analyze(node: MethodNode, interpreter: BackwardAnalysisInt
     val frames = (1..insnList.size()).map { interpreter.newFrame(node.maxLocals) }.toMutableList()
     val insnArray = insnList.toArray()
 
-    // see Figure 9.16 from Dragon book
     var wereChanges: Boolean
 
     do {
         wereChanges = false
-        for (insn in insnArray) {
-            val index = insnList.indexOf(insn)
+        for (index in insnArray.indices.reversed()) {
+            val insn = insnArray[index]
             val newFrame = interpreter.newFrame(node.maxLocals)
             for (successorIndex in graph.getSuccessorsIndices(insn)) {
                 newFrame.mergeFrom(frames[successorIndex])