memory usage very bad with print

I have been writing a custom loader for webpack to do some preprocessing on our js. It's been incredibly slow so I've been doing some timing metrics. With sourcemaps enabled it's taken hundreds of milliseconds to call .print() vs about 10 ms to call prettyPrint(). It's brutally awful. Compiling 7 MB of javascript source results in out of memory errors with node. prettyPrint() is not an effective workaround for me right now because I have some UTF8 control characters which which are unescaped when pretty printing and cause webpack to barf.

Are there any known issues around memory usage and cpu performance of .print()?