Today we continue reading the WRL research report  on Swift Java compiler. We started discussing the results of the performance studies among the  general results observed, method inlining, class hierarchy analysis and global CSE improved performance across all applications.  This is largely due to several small functions implemented in most programs and a missing final specifier and because CHA facilitates method resolution and inlining and escape analysis.
Specific results were also studied.  Field analysis had a large impact on some programs such as mpeg and compress because it eliminates many null checks and bound checks on some constant sized buffers and computation arrays. It plays an even more important role in programs such as mtrt where  there are many refererences to neighbouring elements. In db, Swift successfully inlines a vector object contained within a database entry. Object inlining also inlines some of the smaller arrays used by mtrt program to help eliminate check. The performance of db improves because a significant comparison routine repeatedly generates and uses an enumeration object that can be stack allocated.
Method splitting has been found very useful in programs like db because it makes heavy use of the elementAt  operation and file read operations where there is an ensureOpen check on the file handle. It was also noted that stack allocation does not always improve performance because of the size and effectiveness of the JVM heap. It would show better results if the heap size were small
Synchronization optimization  operations also showed little or no performance improvements and only showed significance in the case of a program which involved synchronization of array and hash data structures.