Both the null check eliminator and the use count computation traverse the inputs of a node using recursion. For complicated expressions this can cause a stack overflow in the compiler resulting in a crash. This has always existed in C1 but the new SSA parser doesn't pin as much so the overflows are easier to cause. I've attached ovf.java which induces the problem in all versions of C1.
The following test case also fails due to the similar issue mentioned in the duplicate bug # 6344424

Test Case : nsk/regression/b6227033