Integer.toString(int num, int radix) may account for nearly 2% of a single iteration of DaCapo bloat's execution time. A cache of common string values for ints isn't maintained. Such a cache would successfully hit with the following percentages:
cache[-128 to 127] =48.8207816707269%
cache[-9 to 9] =30.4192149990097%
cache[0 to 9] =18.860925823555%
Each hit would avoid creating a 33byte char and then allocating a String to wrap it. The single digits cases could in fact use the digits char in java.lang.Number.