From eb415fe4e658a579ef9588e0b57368803d71ac95 Mon Sep 17 00:00:00 2001
From: Tagir Valeev <Tagir.Valeev@jetbrains.com>
Date: Fri, 22 Jun 2018 15:32:54 +0700
Subject: [PATCH] DfaMemoryStateImpl: do not add distinct classes when
 constants are obviously distinct

(cherry picked from commit b3a0e44a1e858f1e54632654f3f7c57e27d1f638)
---
 .../dataFlow/DfaMemoryStateImpl.java          | 44 ++++++++++++++-----
 1 file changed, 32 insertions(+), 12 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 e11014311e14..d325a0772e02 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
@@ -30,6 +30,7 @@ import com.intellij.psi.util.PropertyUtilBase;
 import com.intellij.psi.util.TypeConversionUtil;
 import com.intellij.util.ArrayUtil;
 import com.intellij.util.ObjectUtils;
+import com.intellij.util.ThreeState;
 import com.intellij.util.containers.ContainerUtil;
 import com.intellij.util.containers.Stack;
 import gnu.trove.TIntObjectHashMap;
@@ -959,8 +960,9 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
       return true;
     }
 
+    ThreeState equalByConstants = equalByConstant(c1Index, c2Index);
+    if (equalByConstants != ThreeState.UNSURE) return equalByConstants.toBoolean() != isNegated;
     if (!isNegated) { //Equals
-      if (c1Index.equals(c2Index) || areCompatibleConstants(c1Index, c2Index)) return true;
       if (isUnstableValue(dfaLeft) || isUnstableValue(dfaRight)) return true;
       if (!uniteClasses(c1Index, c2Index)) return false;
 
@@ -975,7 +977,6 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
       myCachedNonTrivialEqClasses = null;
     }
     else { // Not Equals
-      if (c1Index.equals(c2Index) || areCompatibleConstants(c1Index, c2Index)) return false;
       if (isNull(dfaLeft) && isPrimitive(dfaRight) || isNull(dfaRight) && isPrimitive(dfaLeft)) return true;
       myDistinctClasses.addUnordered(c1Index, c2Index);
     }
@@ -992,7 +993,8 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
       return true;
     }
 
-    if (c1Index.equals(c2Index) || areCompatibleConstants(c1Index, c2Index)) return false;
+    ThreeState equalByConstants = equalByConstant(c1Index, c2Index);
+    if (equalByConstants != ThreeState.UNSURE) return !equalByConstants.toBoolean();
     if (isNull(dfaLeft) && isPrimitive(dfaRight) || isNull(dfaRight) && isPrimitive(dfaLeft)) return true;
     myCachedHash = null;
     return myDistinctClasses.addOrdered(c1Index, c2Index);
@@ -1025,17 +1027,35 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
            c2 == null && c1 instanceof PsiVariable;
   }
 
-  private boolean areCompatibleConstants(int i1, int i2) {
-    Double dv1 = getDoubleValue(i1);
-    return dv1 != null && dv1.equals(getDoubleValue(i2));
+  @NotNull
+  private ThreeState equalByConstant(int i1, int i2) {
+    if (i1 == i2) return ThreeState.YES;
+    EqClass ec1 = myEqClasses.get(i1);
+    EqClass ec2 = myEqClasses.get(i2);
+    if (ec1 == null || ec2 == null) return ThreeState.UNSURE;
+    DfaValue constOrBox1 = ec1.findConstant(true);
+    DfaValue constOrBox2 = ec2.findConstant(true);
+    if (constOrBox1 == null || constOrBox2 == null) return ThreeState.UNSURE;
+    if (constOrBox1 instanceof DfaConstValue && constOrBox2 instanceof DfaConstValue) {
+      return areConstantsEqual((DfaConstValue)constOrBox1, (DfaConstValue)constOrBox2);
+    }
+    if (constOrBox1 instanceof DfaBoxedValue && constOrBox2 instanceof DfaBoxedValue) {
+      DfaValue wrapped1 = ((DfaBoxedValue)constOrBox1).getWrappedValue();
+      DfaValue wrapped2 = ((DfaBoxedValue)constOrBox2).getWrappedValue();
+      if (wrapped1 instanceof DfaConstValue && wrapped2 instanceof DfaConstValue &&
+          areConstantsEqual((DfaConstValue)wrapped1, (DfaConstValue)wrapped2) == ThreeState.NO) {
+        return ThreeState.NO;
+      }
+    }
+    return ThreeState.UNSURE;
   }
 
-  @Nullable
-  private Double getDoubleValue(int eqClassIndex) {
-    EqClass ec = myEqClasses.get(eqClassIndex);
-    DfaValue dfaConst = ec == null ? null : ec.findConstant(false);
-    Object constValue = dfaConst instanceof DfaConstValue ? ((DfaConstValue)dfaConst).getValue() : null;
-    return constValue instanceof Number ? ((Number)constValue).doubleValue() : null;
+  private static ThreeState areConstantsEqual(DfaConstValue const1, DfaConstValue const2) {
+    Number value1 = ObjectUtils.tryCast(const1.getValue(), Number.class);
+    Number value2 = ObjectUtils.tryCast(const2.getValue(), Number.class);
+    if (value1 == null || value2 == null) return ThreeState.UNSURE;
+    if (value1 instanceof Long && value2 instanceof Long) return ThreeState.fromBoolean(value1.equals(value2));
+    return ThreeState.fromBoolean(value1.doubleValue() == value2.doubleValue());
   }
 
   @Override