Update README with instructions

README.md

@@ -1,13 +1,43 @@
 # Stack Machine
 
-A series of implementatinos of stack machines to optimize evaluation of arithmetic expressions.
+A series of implementations of stack machines to investigate performance of interpreters on the JVM.
 
 
 ## Benchmarks
 
+To run all benchmarks
+
 `benchmarks / Jmh / run`
 
-Example results
+Example results are below.
+
+
+To inspect performance:
+
+1. Uncomment `javaOptions` in `build.sbt`.
+
+2. It is not necessary to run the benchmarks for so many iterations. You can
+   instead use
+
+   ```
+   benchmarks / Jmh / run -i 1 -wi 0 -f1 -t1 directThreadedFibBenchmark -prof jfr
+   ```
+
+   replacing `directThreadedFibBenchmark` with the name of the benchmark you're
+   interested in. (This means: 1 iteration, 0 warmup iterations, 1 fork, 1
+   thread, record profiling information in JFR format)
+
+
+### Analysis
+
+Get JITWatch from https://github.com/AdoptOpenJDK/jitwatch/releases
+
+`java -jar <jitwatch.jar>`
+
+Open `hotspot_pidXXXXX.log` in the `benchmarks` directory.
+
+
+### Benchmark Results
 
 Ryzen 5 3600, JDK 21
 
@@ -18,6 +48,8 @@ Ryzen 5 3600, JDK 21
 [info] FibonnaciBenchmark.baseFibBenchmark                     thrpt   25  2754.433 ±  18.351  ops/s
 [info] FibonnaciBenchmark.basicStackFibBenchmark               thrpt   25   676.426 ±  18.061  ops/s
 [info] FibonnaciBenchmark.byteCodeFibBenchmark                 thrpt   25  4057.114 ±  69.842  ops/s
+[info] FibonnaciBenchmark.directThreadedFibBenchmark           thrpt   25  451783334.122 ± 18008803.137  ops/s
+[info] FibonnaciBenchmark.directThreaded3FibBenchmark          thrpt   25  528655333.613 ± 13105914.900  ops/s
 [info] FibonnaciBenchmark.optimizedStack2FibBenchmark          thrpt   25  3575.290 ±  45.085  ops/s
 [info] FibonnaciBenchmark.optimizedStack3FibBenchmark          thrpt   25  3567.815 ±  50.533  ops/s
 [info] FibonnaciBenchmark.optimizedStackFibBenchmark           thrpt   25  3631.189 ±   8.750  ops/s