private final float applyMod(float f,String mod)
{
 if(mod==null) return f;
 float m;
 try
 {
   m=Float.valueOf(mod.substring(1)).floatValue();
 }
 catch ( NumberFormatException z)
  {
   System.out.println("[GC_CONFIG_ERROR] Invalid number in LRU modifier '"+mod+"'");
   throw z;
  }
 switch(mod.charAt(0))
 {
  case '+':f+=m;break;
  case '-':f-=m;break;
  case '*':f*=m;break;
  case '/':f/=m;break;
  case '=':if(f>=m) f=REFAGE_MAX-1;
           break;
  default:
   System.out.println("[GC_CONFIG_ERROR] Invalid action in LRU modifier '"+mod+"'");
   throw new IllegalArgumentException("Unknown action "+mod.charAt(0));
 }
 return f;
}