The example used is the venerable Logger class from the log4j package. It seem implausible that imprecise constant folding would cause a measurable performance

The example used is the venerable Logger class from the log4j package. It seem implausible that imprecise constant folding would cause a measurable performance decrease when using that class. So to me the point is not clear. A more convincing argument would be before and after stats of a benchmark showing x% performance increase.