This is the very simple test case:

class d2f {

  public static boolean foo() {
    double d = Float.NaN;
    return Float.isNaN((float) d);
  }

  public static void main(String[] args) {
    System.exit(foo() ? 2 : 3);
  }
}

This is the assertion:

wallon:~/junk> gamma_g -Xcomp -XX:CompileOnly=.foo d2f
VM Warning: cannot find gamma_g; using $JAVA_HOME
VM option 'CompileOnly=.foo'
#
# HotSpot Virtual Machine Error, assertion failure
#
# assert(i < _max, "oob")
# /home/rieber/hotsparc/_workspaces/sb.beta//src/share/vm/opto/block.hpp, 41#
#
# Error happend during: method compilation
#
# compiling d2f.foo
#
HotSpot Compiler Failure
Do you want to exclude compilation of this method in future runs?
^C
wallon:~/junk>

******* See the comments section.