From 4143e6c8d7cc3cdf4d7cc009a94a41869a6c1896 Mon Sep 17 00:00:00 2001
From: konsoletyper <konsoletyper@gmail.com>
Date: Fri, 7 Mar 2014 23:13:07 +0400
Subject: [PATCH] Repairs common subexpression elimination and renames it to
 global value numbering, as it is really pessimistic GVN

---
 .../main/java/org/teavm/optimization/ClassSetOptimizer.java   | 3 +--
 ...ubexpressionElimination.java => GlobalValueNumbering.java} | 4 ++--
 2 files changed, 3 insertions(+), 4 deletions(-)
 rename teavm-core/src/main/java/org/teavm/optimization/{CommonSubexpressionElimination.java => GlobalValueNumbering.java} (99%)

diff --git a/teavm-core/src/main/java/org/teavm/optimization/ClassSetOptimizer.java b/teavm-core/src/main/java/org/teavm/optimization/ClassSetOptimizer.java
index 3a67b82c7..1faca0b76 100644
--- a/teavm-core/src/main/java/org/teavm/optimization/ClassSetOptimizer.java
+++ b/teavm-core/src/main/java/org/teavm/optimization/ClassSetOptimizer.java
@@ -36,8 +36,7 @@ public class ClassSetOptimizer {
     }
 
     private List<MethodOptimization> getOptimizations() {
-        // TODO: repair CommonSubexpressionElimination and get it back here
-        return Arrays.<MethodOptimization>asList(new UnusedVariableElimination());
+        return Arrays.<MethodOptimization>asList(new GlobalValueNumbering(), new UnusedVariableElimination());
     }
 
     public void optimizeAll(ListableClassHolderSource classSource) {
diff --git a/teavm-core/src/main/java/org/teavm/optimization/CommonSubexpressionElimination.java b/teavm-core/src/main/java/org/teavm/optimization/GlobalValueNumbering.java
similarity index 99%
rename from teavm-core/src/main/java/org/teavm/optimization/CommonSubexpressionElimination.java
rename to teavm-core/src/main/java/org/teavm/optimization/GlobalValueNumbering.java
index eb95f54da..550734318 100644
--- a/teavm-core/src/main/java/org/teavm/optimization/CommonSubexpressionElimination.java
+++ b/teavm-core/src/main/java/org/teavm/optimization/GlobalValueNumbering.java
@@ -30,7 +30,7 @@ import org.teavm.model.util.ProgramUtils;
  *
  * @author Alexey Andreev
  */
-public class CommonSubexpressionElimination implements MethodOptimization {
+public class GlobalValueNumbering implements MethodOptimization {
     private Map<String, KnownValue> knownValues = new HashMap<>();
     private boolean eliminate;
     private int[] map;
@@ -137,7 +137,7 @@ public class CommonSubexpressionElimination implements MethodOptimization {
 
     private void bind(int var, String value) {
         KnownValue known = knownValues.get(value);
-        if (known != null && domTree.dominates(known.location, currentBlockIndex)) {
+        if (known != null && domTree.dominates(known.location, currentBlockIndex) && known.value != var) {
             eliminate = true;
             map[var] = known.value;
         } else {