From 8718f8b5dcb09626e444cbb24198c9bccfc82cb3 Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Wed, 16 Apr 2014 19:57:15 +0200
Subject: [PATCH] replace DfaMemoryStateImpl.areEquivalent with a more
 efficient version requiring less eq class traversals (IDEA-123826)

---
 .../codeInspection/dataFlow/DfaMemoryStateImpl.java | 13 ++++---------
 .../codeInspection/dataFlow/StateMerger.java        |  3 ++-
 2 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DfaMemoryStateImpl.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DfaMemoryStateImpl.java
index a50e75af42c3..6f374b1f5d95 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DfaMemoryStateImpl.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DfaMemoryStateImpl.java
@@ -268,13 +268,8 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
     return myEqClasses.size() - 1;
   }
 
-  boolean areEquivalent(DfaValue val1, DfaValue val2) {
-    int index = getEqClassIndex(val1);
-    return index >= 0 && index == getEqClassIndex(val2);
-  }
-
   @NotNull
-  private List<DfaValue> getEqClassesFor(@NotNull DfaValue dfaValue) {
+  List<DfaValue> getEquivalentValues(@NotNull DfaValue dfaValue) {
     int index = getEqClassIndex(dfaValue);
     EqClass set = index == -1 ? null : myEqClasses.get(index);
     if (set == null) {
@@ -284,7 +279,7 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
   }
 
   private boolean canBeNaN(@NotNull DfaValue dfaValue) {
-    for (DfaValue eq : getEqClassesFor(dfaValue)) {
+    for (DfaValue eq : getEquivalentValues(dfaValue)) {
       if (eq instanceof DfaBoxedValue) {
         eq = ((DfaBoxedValue)eq).getWrappedValue();
       }
@@ -298,7 +293,7 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
 
 
   private boolean isEffectivelyNaN(@NotNull DfaValue dfaValue) {
-    for (DfaValue eqClass : getEqClassesFor(dfaValue)) {
+    for (DfaValue eqClass : getEquivalentValues(dfaValue)) {
       if (isNaN(eqClass)) return true;
     }
     return false;
@@ -323,7 +318,7 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
       }
       if (valueToWrap instanceof DfaVariableValue) {
         if (PsiType.BOOLEAN.equals(((DfaVariableValue)valueToWrap).getVariableType())) return true;
-        for (DfaValue value : getEqClassesFor(valueToWrap)) {
+        for (DfaValue value : getEquivalentValues(valueToWrap)) {
           if (value instanceof DfaConstValue && cacheable((DfaConstValue)value)) return true;
         }
       }
diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StateMerger.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StateMerger.java
index d691469db9e1..1fa65263de27 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StateMerger.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StateMerger.java
@@ -118,9 +118,10 @@ class StateMerger {
 
   private static Set<DfaConstValue> getOtherInequalities(Fact removedFact, LinkedHashSet<Fact> memberFacts, DfaMemoryStateImpl state) {
     Set<DfaConstValue> otherInequalities = ContainerUtil.newLinkedHashSet();
+    Set<DfaValue> eqValues = ContainerUtil.newHashSet(state.getEquivalentValues((DfaValue)removedFact.myArg));
     for (Fact candidate : memberFacts) {
       if (candidate.myType == FactType.equality && !candidate.myPositive && candidate.myVar == removedFact.myVar &&
-          !state.areEquivalent((DfaValue)candidate.myArg, (DfaValue)removedFact.myArg) && 
+          !eqValues.contains((DfaValue)candidate.myArg) &&
           candidate.myArg instanceof DfaConstValue) {
         otherInequalities.add((DfaConstValue)candidate.myArg);
       }