perf.log

% date; time (for i in {1..10}; do echo ../scala2/sandbox/perf/scala/*.scala; done) | ~/scala/2.11.6/bin/scalac -J-Xmx2G -d /tmp -Xresident 2>&1 | perl -pne 'print scalar(localtime()), " ";'
Thu Apr 23 20:30:37 AEST 2015
Thu Apr 23 20:30:38 2015
Thu Apr 23 20:30:43 2015 nsc>
Thu Apr 23 20:30:45 2015 nsc>
Thu Apr 23 20:30:46 2015 nsc>
Thu Apr 23 20:30:48 2015 nsc>
Thu Apr 23 20:30:49 2015 nsc>
Thu Apr 23 20:30:50 2015 nsc>
Thu Apr 23 20:30:51 2015 nsc>
Thu Apr 23 20:30:52 2015 nsc>
Thu Apr 23 20:30:53 2015 nsc>
Thu Apr 23 20:30:54 2015 nsc>
Thu Apr 23 20:30:54 2015 nsc>
real	0m16.599s
user	0m48.036s
sys	0m2.730s


% time ~/scala/2.11.6/bin/scalac -J-NOJVM -d ../scala2/sandbox/perf/scala/*.scala 2>&1 # 2000 files
Unrecognized option: -NOJVM
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

real	0m10.389s
user	0m10.293s
sys	0m0.067s

shell_perf.log

% time bash sandbox/test /foo/bar/foo/bar/foo/bar/foo/bar/{1..2000}

real	0m9.082s
user	0m9.050s
sys	0m0.020s

% time bash sandbox/test /foo/bar/foo/bar/foo/bar/foo/bar/{1..1000}

real	0m2.250s
user	0m2.241s
sys	0m0.007s

% time bash sandbox/test /foo/bar/foo/bar/foo/bar/foo/bar/{1..1000}

real	0m2.244s
user	0m2.236s
sys	0m0.007s

% time bash sandbox/test /foo/bar/foo/bar/foo/bar/foo/bar/{1..2000}

real	0m9.051s
user	0m9.026s
sys	0m0.017s

% time bash sandbox/test /foo/bar/foo/bar/foo/bar/foo/bar/{1..3000}

real	0m20.623s
user	0m20.532s
sys	0m0.050s

% time bash sandbox/test /foo/bar/foo/bar/foo/bar/foo/bar/{1..4000}

real	0m36.581s
user	0m36.443s
sys	0m0.108s

test

#!/bin/bash

# Minimized from scalac bach wrapper. This pattern of command line processing shows quadratic performance.
# It was introduced https://github.com/scala/scala/commit/fbe897d165bfbb8cda05e4b25f0f773288653f54

declare -a scala_args

while [[ $# -gt 0 ]]; do
  case "$1" in
    -D*)
      shift
      ;;
    -J*)
      shift
      ;;
    -toolcp)
      shift 2
      ;;
    -nobootcp)
      unset usebootcp
      shift
      ;;
    -usebootcp)
      usebootcp="true"
      shift
      ;;
    -debug)
      SCALA_RUNNER_DEBUG=1
      shift
      ;;
    *)
      scala_args=("${scala_args[@]}" "$1")
      shift
      ;;
  esac
done

# reset "$@@" to the remaining args
set -- "${scala_args[@]}"