update String benchmarks & d8 version

Author: alex28sh

build.gradle.kts

@@ -53,7 +53,7 @@ apply<BinaryenRootPlugin>()
 the<BinaryenRootEnvSpec>().version.set("123")
 
 apply<D8Plugin>()
-the<D8EnvSpec>().version.set("13.4.61")
+the<D8EnvSpec>().version.set("14.2.133")
 
 allprojects.forEach {
     it.tasks.withType<org.jetbrains.kotlin.gradle.targets.js.npm.tasks.KotlinNpmInstallTask>().configureEach {
@@ -138,6 +138,7 @@ benchmark {
             "microBenchmarks.ArrayCopyBenchmark.copyInSameArray",
             "microBenchmarks.BunnymarkBenchmark.testBunnymark",
             "microBenchmarks.CoordinatesSolverBenchmark.solve",
+            "microBenchmarks.StringBenchmark.subSequence",
         )
         with(create("fastMicro")) {
             iterations = 5

src/commonMain/kotlin/microBenchmarks/StringBenchmark.kt

@@ -17,10 +17,13 @@
 package microBenchmarks
 
 import kotlinx.benchmark.*
+import kotlin.math.roundToInt
+import kotlin.math.sqrt
 
 @State(Scope.Benchmark)
 class StringBenchmark {
     private var csv: String = ""
+    private val subSequenceRanges = mutableListOf<Pair<Int, Int>>()
 
     @Setup
     fun setup() {
@@ -30,6 +33,12 @@ class StringBenchmark {
             csv += ","
         }
         csv += 0.0
+
+        for (i in 1..sqrt(BENCHMARK_SIZE.toDouble()).roundToInt()) {
+            for (j in 0..csv.length - i) {
+                subSequenceRanges.add(Pair(j, j + i))
+            }
+        }
     }
 
     @Benchmark
@@ -92,4 +101,23 @@ class StringBenchmark {
         }
         return sum
     }
+
+    @Benchmark
+    fun iterateCharsCsv(): Int {
+        var sum = 0
+        for (i in 0 until BENCHMARK_SIZE) {
+            sum += csv[i].code
+        }
+        return sum
+    }
+
+    @Benchmark
+    fun subSequenceCsv(): Int {
+        var sum = 0
+        for (range in subSequenceRanges) {
+            val subString = csv.subSequence(range.first, range.second)
+            sum += subString[0].code
+        }
+        return sum
+    }
 }