src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/calc/IntegerEqualsNode.java

*** 163,190 ****
--- 163,252 ----
                  AddNode addX = (AddNode) forX;
                  AddNode addY = (AddNode) forY;
                  ValueNode v1 = null;
                  ValueNode v2 = null;
                  if (addX.getX() == addY.getX()) {
+                     // (x + y) == (x + z) => y == z
                      v1 = addX.getY();
                      v2 = addY.getY();
                  } else if (addX.getX() == addY.getY()) {
+                     // (x + y) == (z + x) => y == z
                      v1 = addX.getY();
                      v2 = addY.getX();
                  } else if (addX.getY() == addY.getX()) {
+                     // (y + x) == (x + z) => y == z
                      v1 = addX.getX();
                      v2 = addY.getY();
                  } else if (addX.getY() == addY.getY()) {
+                     // (y + x) == (z + x) => y == z
                      v1 = addX.getX();
                      v2 = addY.getX();
                  }
                  if (v1 != null) {
                      assert v2 != null;
                      return create(v1, v2, view);
                  }
              }
  
+             if (forX instanceof SubNode && forY instanceof SubNode) {
+                 SubNode subX = (SubNode) forX;
+                 SubNode subY = (SubNode) forY;
+                 ValueNode v1 = null;
+                 ValueNode v2 = null;
+                 if (subX.getX() == subY.getX()) {
+                     // (x - y) == (x - z) => y == z
+                     v1 = subX.getY();
+                     v2 = subY.getY();
+                 } else if (subX.getY() == subY.getY()) {
+                     // (y - x) == (z - x) => y == z
+                     v1 = subX.getX();
+                     v2 = subY.getX();
+                 }
+                 if (v1 != null) {
+                     assert v2 != null;
+                     return create(v1, v2, view);
+                 }
+             }
+ 
+             if (forX instanceof AddNode) {
+                 AddNode addNode = (AddNode) forX;
+                 if (addNode.getX() == forY) {
+                     // (x + y) == x => y == 0
+                     return create(addNode.getY(), ConstantNode.forIntegerStamp(view.stamp(addNode), 0), view);
+                 } else if (addNode.getY() == forY) {
+                     // (x + y) == y => x == 0
+                     return create(addNode.getX(), ConstantNode.forIntegerStamp(view.stamp(addNode), 0), view);
+                 }
+             }
+ 
+             if (forY instanceof AddNode) {
+                 AddNode addNode = (AddNode) forY;
+                 if (addNode.getX() == forX) {
+                     // x == (x + y) => y == 0
+                     return create(addNode.getY(), ConstantNode.forIntegerStamp(view.stamp(addNode), 0), view);
+                 } else if (addNode.getY() == forX) {
+                     // y == (x + y) => x == 0
+                     return create(addNode.getX(), ConstantNode.forIntegerStamp(view.stamp(addNode), 0), view);
+                 }
+             }
+ 
+             if (forX instanceof SubNode) {
+                 SubNode subNode = (SubNode) forX;
+                 if (subNode.getX() == forY) {
+                     // (x - y) == x => y == 0
+                     return create(subNode.getY(), ConstantNode.forIntegerStamp(view.stamp(subNode), 0), view);
+                 }
+             }
+ 
+             if (forY instanceof SubNode) {
+                 SubNode subNode = (SubNode) forY;
+                 if (forX == subNode.getX()) {
+                     // x == (x - y) => y == 0
+                     return create(subNode.getY(), ConstantNode.forIntegerStamp(view.stamp(subNode), 0), view);
+                 }
+             }
+ 
              return super.canonical(constantReflection, metaAccess, options, smallestCompareWidth, condition, unorderedIsTrue, forX, forY, view);
          }
  
          @Override
          protected LogicNode canonicalizeSymmetricConstant(ConstantReflectionProvider constantReflection, MetaAccessProvider metaAccess, OptionValues options, Integer smallestCompareWidth,
*** 304,309 ****
--- 366,386 ----
                  return TriState.TRUE;
              }
          }
          return TriState.UNKNOWN;
      }
+ 
+     @Override
+     public TriState implies(boolean thisNegated, LogicNode other) {
+         // x == y => !(x < y)
+         // x == y => !(y < x)
+         if (!thisNegated && other instanceof IntegerLessThanNode) {
+             ValueNode otherX = ((IntegerLessThanNode) other).getX();
+             ValueNode otherY = ((IntegerLessThanNode) other).getY();
+             if ((getX() == otherX && getY() == otherY) || (getX() == otherY && getY() == otherX)) {
+                 return TriState.FALSE;
+             }
+         }
+ 
+         return super.implies(thisNegated, other);
+     }
  }