Design and Analysis of a Scala Benchmark Suite for the Java Virtual Machine

In the last decade, virtual machines (VMs) for high-level languages have become pervasive, as they promise both portability and high performance. However, these virtual machines were often designed to support just a single language well. The design of the Java Virtual Machine (JVM), for example, is heavily influenced by the Java programming language. Despite its current bias towards Java, in recent years the JVM in particular has been targeted by numerous new languages: Scala, Groovy, Clojure, and others. This trend has not been reflected in JVM research, though; all major benchmark suites for the JVM are still firmly focused on the Java language rather than on the language ecosystem as a whole. This state of affairs threatens to perpetuate the bias towards Java, as JVM implementers strive to “make the common case fast.” But what is common for Java may be uncommon for other, popular languages. One of these other languages is Scala, a language with both object-oriented and functional features, whose popularity has grown tremendously since its first public appearance in 2003. What characteristics Scala programs have or have not in common with Java programs has been an open question, though. One contribution of this thesis is therefore the design of a Scala benchmark suite that is on par with modern, widely-accepted Java benchmark suites. Another contribution is the subsequent analysis of this suite and an in-depth, VM-independent comparison with the DaCapo 9.12 benchmark suite, the premier suite used in JVM research. The analysis shows that Scala programs exhibit not only a distinctive instruction mix but also object demographics close to those of the Scala language’s functional ancestors. This thesis furthermore shows that these differences can have a marked effect on the performance of Scala programs on modern high-performance JVMs. While JVMs exhibit remarkably similar performance on Java programs, the performance of Scala programs varies considerably, with the fastest JVM being more than three times faster than the slowest