SONARJAVA-1389 SE: better computation of hashcodes

Author: benzonico

java-squid/src/main/java/org/sonar/java/se/ExplodedGraph.java

@@ -47,6 +47,7 @@ Node getNode(ProgramPoint programPoint, @Nullable ProgramState programState) {
   }
 
   public static class ProgramPoint {
+    private int hashcode;
     final CFG.Block block;
     final int i;
 
@@ -57,7 +58,10 @@ public ProgramPoint(CFG.Block block, int i) {
 
     @Override
     public int hashCode() {
-      return block.id() * 31 + i;
+      if(hashcode == 0) {
+        hashcode = block.id() * 31 + i;
+      }
+      return hashcode;
     }
 
     @Override

java-squid/src/main/java/org/sonar/java/se/SymbolicValue.java

@@ -19,7 +19,6 @@
  */
 package org.sonar.java.se;
 
-import com.google.common.base.Objects;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Maps;
@@ -76,12 +75,12 @@ public boolean equals(Object o) {
         return false;
       }
       ObjectSymbolicValue that = (ObjectSymbolicValue) o;
-      return Objects.equal(id, that.id);
+      return id == that.id;
     }
 
     @Override
     public int hashCode() {
-      return Objects.hashCode(id);
+      return id;
     }
 
     @Override