From b73ea2fde3949bcd1366cc8778c007619b627481 Mon Sep 17 00:00:00 2001
From: Guillaume Martres <smarter@ubuntu.com>
Date: Thu, 13 Nov 2014 17:18:53 +0100
Subject: [PATCH] Add option to optimize the JVM for short-runnning
 applications

Ideally, dotc should reuse a resident compiler and we should not fork sbt
for every task. Until this happens, this option is useful for
development. Fixes #222.

Usage:
$ sbt -DOshort=""
$ ./bin/dotc -Oshort foo.scala
---
 bin/dotc            | 3 +++
 project/Build.scala | 9 ++++++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/bin/dotc b/bin/dotc
index cafd80f03363..72ac3141a6ad 100755
--- a/bin/dotc
+++ b/bin/dotc
@@ -185,6 +185,9 @@ case "$1" in
     -d|-debug) debug=true && shift ;;
     -q|-quiet) quiet=true && shift ;;
 
+    # Optimize for short-running applications, see https://github.com/lampepfl/dotty/issues/222
+    -Oshort) addJava "-XX:+TieredCompilation -XX:TieredStopAtLevel=1" && shift ;;
+
         -repl) main_class=$ReplMain && shift ;;
      -compile) main_class=$CompilerMain && shift ;;
          -run) main_class=$ReplMain && shift ;;
diff --git a/project/Build.scala b/project/Build.scala
index 33a09a4f7224..9e2633136642 100644
--- a/project/Build.scala
+++ b/project/Build.scala
@@ -68,7 +68,14 @@ object DottyBuild extends Build {
          else
            List()
 
-      agentOptions ::: travis_build ::: fullpath
+       val tuning =
+         if (sys.props.isDefinedAt("Oshort"))
+           // Optimize for short-running applications, see https://github.com/lampepfl/dotty/issues/222
+           List("-XX:+TieredCompilation", "-XX:TieredStopAtLevel=1")
+        else
+          List()
+
+      tuning ::: agentOptions ::: travis_build ::: fullpath
     }
   )