Warmup Lua interpreter before benchmarks

src/test/java/cc/tweaked/cobalt/benchmark/BenchmarkFull.java

@@ -6,6 +6,7 @@
 import org.openjdk.jmh.runner.options.Options;
 import org.openjdk.jmh.runner.options.OptionsBuilder;
 import org.openjdk.jmh.runner.options.TimeValue;
+import org.openjdk.jmh.runner.options.WarmupMode;
 
 /**
  * Runs all benchmarks within the {@code cc.tweaked.cobalt.benchmark} package.
@@ -17,6 +18,8 @@ private BenchmarkFull() {
 	public static void main(String... args) throws RunnerException {
 		Options opts = new OptionsBuilder()
 			.include("cc.tweaked.cobalt.benchmark.*")
+			.exclude("cc.tweaked.cobalt.benchmark.WarmupBenchmarks.*")
+			.includeWarmup("cc.tweaked.cobalt.benchmark.WarmupBenchmarks.*")
 			.warmupIterations(3)
 			.warmupTime(TimeValue.milliseconds(1000))
 			.measurementIterations(5)

src/test/java/cc/tweaked/cobalt/benchmark/WarmupBenchmarks.java

@@ -0,0 +1,54 @@
+package cc.tweaked.cobalt.benchmark;
+
+import org.openjdk.jmh.annotations.Measurement;
+import org.openjdk.jmh.annotations.Warmup;
+import org.squiddev.cobalt.Constants;
+
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Generates a Lua program which attempts to execute all parts of the Lua interpreter, ensuring that our actual
+ * benchmarks don't overspecialise for a specific case.
+ */
+@Warmup(time = 2, timeUnit = TimeUnit.SECONDS)
+@Measurement(iterations = 0)
+public class WarmupBenchmarks extends LuaBenchmark {
+	public WarmupBenchmarks() {
+		super(makeFile(), s -> Constants.NONE);
+	}
+
+	private static String makeFile() {
+		var out = new StringBuilder();
+		out.append("local x, y, _ = 5.2, '123'\n");
+
+		// Arithmetic and Lua operations
+		for (var op : List.of("+", "-", "*", "/", "%", "^", "..")) {
+			addOperation(out, "x", op, "x");
+			addOperation(out, "x", op, "y");
+			addOperation(out, "x", op, "0");
+			addOperation(out, "0", op, "x");
+		}
+
+		// Comparison operations
+		for (var op : List.of("==", "<", "<=")) {
+			addOperation(out, "x", op, "x");
+			addOperation(out, "x", op, "0");
+			addOperation(out, "0", op, "x");
+
+			addOperation(out, "y", op, "y");
+			addOperation(out, "y", op, "''");
+			addOperation(out, "''", op, "y");
+		}
+
+		// Basic control flow
+		out.append("for i = 1, 10 do _ = 0 end\n");
+		out.append("for k in pairs(_G) do _ = _G[k] end\n");
+
+		return out.toString();
+	}
+
+	private static void addOperation(StringBuilder out, String lhs, String op, String rhs) {
+		out.append("_ = ").append(lhs).append(" ").append(op).append(" ").append(rhs).append("\n");
+	}
+}