Renderscript compilation doesn't generate files in 'gen' dir

Renderscript compilation doesn't generate files in 'gen' dir

I have a renderscript in my android project which compiles properly. The
.bc file generated looks correct and there's also the corresponding .class
file that gets generated (ScriptC_...class). However, I can't seem to find
the 'gen' directory.
How do I go about fixing this? I'm on AndroidStudio 0.2.5, API 17. Here's
the project structure:
<root>
.idea
build
<projectname>
classes
ScriptC_blah.class
lib
src
main
gen
java
...moredirs...
<sourcecode>
app.iml
build.gradle