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

*** 78,87 ****
--- 78,103 ----
              int mask = op.getShiftAmountMask(stamp);
              amount &= mask;
              if (amount == 0) {
                  return forX;
              }
+ 
+             Stamp xStampGeneric = forX.stamp(view);
+             if (xStampGeneric instanceof IntegerStamp) {
+                 IntegerStamp xStamp = (IntegerStamp) xStampGeneric;
+ 
+                 if (xStamp.lowerBound() >>> amount == xStamp.upperBound() >>> amount) {
+                     // The result of the shift is constant.
+                     return ConstantNode.forIntegerKind(stamp.getStackKind(), xStamp.lowerBound() >>> amount);
+                 }
+ 
+                 if (amount == xStamp.getBits() - 1 && xStamp.lowerBound() == -1 && xStamp.upperBound() == 0) {
+                     // Shift is equivalent to a negation, i.e., turns -1 into 1 and keeps 0 at 0.
+                     return NegateNode.create(forX, view);
+                 }
+             }
+ 
              if (forX instanceof ShiftNode) {
                  ShiftNode<?> other = (ShiftNode<?>) forX;
                  if (other.getY().isConstant()) {
                      int otherAmount = other.getY().asJavaConstant().asInt() & mask;
                      if (other instanceof UnsignedRightShiftNode) {