OptimizePtrCompare is overaggressive in converting comparisons to not-equal. It appears that this is a result of is_return_allocated() in bcEscapeAnalyzer being not conservative enough. The program below fails with "-XX:CompileOnly=.visitAndPop". Passes with "-XX:-OptimizePtrCompare". Forthcoming contribution with proposed fix. import java.util.ArrayList; import java.util.List; public class TestMarkChecker { static TestMarkChecker dummy; class Marker { } List<Marker> markerList = new ArrayList<>(); // Suppress compilation of this method, it must be processed // by the bytecode escape analyzer. // Make a new marker and put it on the List Marker getMarker() { // result escapes through markerList final Marker result = new Marker(); markerList.add(result); return result; } void visit(int depth) { // Make a new marker getMarker(); // Call visitAndPop every once in a while // Cap the depth of our recursive visits if (depth % 10 == 2) { visitAndPop(depth + 1); } else if (depth < 15) { visit(depth + 1); } } void visitAndPop(int depth) { // Random dummy allocation to force EscapeAnalysis to process this method dummy = new TestMarkChecker(); // Make a new marker Marker marker = getMarker(); visit(depth + 1); // Walk and pop the marker list up to the current marker boolean found = false; for (int i = markerList.size() - 1; i >= 0; i--) { Marker removed = markerList.remove(i); // In the failure, EA mistakenly converts this comparison to false if (removed == marker) { found = true; break; } } if (!found) { throw new RuntimeException("test fails"); } } public static void main(String args[]) { TestMarkChecker tc = new TestMarkChecker(); // Warmup and run enough times for (int i = 0; i < 20000; i++) { tc.visit(0); } } }