--- old/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/calc/IntegerLessThanNode.java 2019-03-12 08:09:50.403669305 +0100 +++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/calc/IntegerLessThanNode.java 2019-03-12 08:09:50.039666945 +0100 @@ -50,6 +50,7 @@ import jdk.vm.ci.meta.JavaKind; import jdk.vm.ci.meta.MetaAccessProvider; import jdk.vm.ci.meta.PrimitiveConstant; +import jdk.vm.ci.meta.TriState; @NodeInfo(shortName = "<") public final class IntegerLessThanNode extends IntegerLowerThanNode { @@ -225,7 +226,6 @@ } } } - } } @@ -296,4 +296,29 @@ return StampFactory.forInteger(bits, cast(min, bits), cast(max, bits)); } } + + @Override + public TriState implies(boolean thisNegated, LogicNode other) { + if (!thisNegated) { + if (other instanceof IntegerLessThanNode) { + ValueNode otherX = ((IntegerLessThanNode) other).getX(); + ValueNode otherY = ((IntegerLessThanNode) other).getY(); + // x < y => !y < x + if (getX() == otherY && getY() == otherX) { + return TriState.FALSE; + } + } + + // x < y => !x == y + // x < y => !y == x + if (other instanceof IntegerEqualsNode) { + ValueNode otherX = ((IntegerEqualsNode) other).getX(); + ValueNode otherY = ((IntegerEqualsNode) other).getY(); + if ((getX() == otherX && getY() == otherY) || (getX() == otherY && getY() == otherX)) { + return TriState.FALSE; + } + } + } + return super.implies(thisNegated, other); + } }