v2 blackholes, java8

pom.xml

@@ -9,8 +9,8 @@
     <version>1.0-SNAPSHOT</version>
 
     <properties>
-        <maven.compiler.source>20</maven.compiler.source>
+        <maven.compiler.source>8</maven.compiler.source>
-        <maven.compiler.target>20</maven.compiler.target>
+        <maven.compiler.target>8</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>
 
@@ -41,9 +41,9 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.8.0</version>
                 <configuration>
-                    <compilerVersion>9</compilerVersion>
+                    <compilerVersion>8</compilerVersion>
-                    <source>9</source>
+                    <source>8</source>
-                    <target>9</target>
+                    <target>8</target>
                 </configuration>
             </plugin>
             <plugin>

report.md

@@ -0,0 +1,45 @@
+**cStyle**
+```
+23,57%    0x0000000112765de8: ;*aaload {reexecute=0 rethrow=0 return_oop=0}
+; - java.util.ArrayList::elementData@5 (line 411)
+; - java.util.ArrayList::get@11 (line 428)
+; - com.github.shautvast.benchmarks.loops.LoopBenchmark::cStyle@20 (line 35)
+; - com.github.shautvast.benchmarks.loops.jmh_generated.LoopBenchmark_cStyle_jmhTest::cStyle_avgt_jmhStub@19 (line 193)
+
+30,39%    0x0000000112765e00: ;*getfield coder {reexecute=0 rethrow=0 return_oop=0}
+; - java.lang.String::coder@7 (line 4556)
+; - java.lang.String::length@6 (line 1499)
+; - com.github.shautvast.benchmarks.loops.LoopBenchmark::cStyle@28 (line 35)
+; - com.github.shautvast.benchmarks.loops.jmh_generated.LoopBenchmark_cStyle_jmhTest::cStyle_avgt_jmhStub@19 (line 193)
+
+27,83%    0x0000000112765e28: ;*getfield coder {reexecute=0 rethrow=0 return_oop=0}
+; - java.lang.String::coder@7 (line 4556)
+; - java.lang.String::length@6 (line 1499)
+; - com.github.shautvast.benchmarks.loops.LoopBenchmark::cStyle@28 (line 35)
+; - com.github.shautvast.benchmarks.loops.jmh_generated.LoopBenchmark_cStyle_jmhTest::cStyle_avgt_jmhStub@19 (line 193)
+
+5,18%    0x0000000112765e3c: ;*if_icmpge {reexecute=0 rethrow=0 return_oop=0}
+; - com.github.shautvast.benchmarks.loops.LoopBenchmark::cStyle@10 (line 34)
+; - com.github.shautvast.benchmarks.loops.jmh_generated.LoopBenchmark_cStyle_jmhTest::cStyle_avgt_jmhStub@19 (line 193)
+```
+
+**enhancedForLoop**
+```
+29,09%    0x0000000113e5a748: ;*aaload {reexecute=0 rethrow=0 return_oop=0}
+; - java.util.ArrayList$Itr::next@64 (line 975)
+; - com.github.shautvast.benchmarks.loops.LoopBenchmark::enhancedForLoop@25 (line 52)
+; - com.github.shautvast.benchmarks.loops.jmh_generated.LoopBenchmark_enhancedForLoop_jmhTest::enhancedForLoop_avgt_jmhStub@19 (line 193)  
+
+23,18%    0x0000000113e5a760: ;*getfield coder {reexecute=0 rethrow=0 return_oop=0}
+; - java.lang.String::coder@7 (line 4556)
+; - java.lang.String::length@6 (line 1499)
+; - com.github.shautvast.benchmarks.loops.LoopBenchmark::enhancedForLoop@38 (line 53)
+; - com.github.shautvast.benchmarks.loops.jmh_generated.LoopBenchmark_enhancedForLoop_jmhTest::enhancedForLoop_avgt_jmhStub@19 (line 193)
+
+17,19%    0x0000000113e5a788: ;*getfield coder {reexecute=0 rethrow=0 return_oop=0}
+; - java.lang.String::coder@7 (line 4556)
+; - java.lang.String::length@6 (line 1499)
+; - com.github.shautvast.benchmarks.loops.LoopBenchmark::enhancedForLoop@38 (line 53)
+; - com.github.shautvast.benchmarks.loops.jmh_generated.LoopBenchmark_enhancedForLoop_jmhTest::enhancedForLoop_avgt_jmhStub@19 (line 193)  
+```
+

src/main/java/com/github/shautvast/benchmarks/loops/LoopBenchmark.java

@@ -1,6 +1,7 @@
 package com.github.shautvast.benchmarks.loops;
 
 import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.infra.Blackhole;
 import org.openjdk.jmh.profile.*;
 import org.openjdk.jmh.runner.Runner;
 import org.openjdk.jmh.runner.RunnerException;
@@ -13,10 +14,9 @@ import java.util.concurrent.TimeUnit;
 @BenchmarkMode(Mode.AverageTime)
 @OutputTimeUnit(TimeUnit.NANOSECONDS)
 @Fork(value = 1)
+@State(Scope.Thread)
 public class LoopBenchmark {
 
-    @org.openjdk.jmh.annotations.State(Scope.Thread)
-    public static class State {
     final static int LIST_SIZE = 1000;
     List<String> list = new ArrayList<>(LIST_SIZE);
 
@@ -26,38 +26,45 @@ public class LoopBenchmark {
             list.add(UUID.randomUUID().toString());
         }
     }
+
+    @Benchmark
+    public void forLoop(Blackhole bh) {
+        for (int i = 0; i < LIST_SIZE; i++) {
+            bh.consume(list.get(i));
+        }
     }
 
     @Benchmark
-    public long cStyle(LoopBenchmark.State state) {
+    public void whileLoop(Blackhole bh) {
-        long totalLength = 0;
+        int i = 0;
-        for (int i = 0; i < State.LIST_SIZE; i++) {
+        while (i < LIST_SIZE) {
-            totalLength += state.list.get(i).length();
+            bh.consume(list.get(i));
+            i++;
         }
-        return totalLength;
     }
 
     @Benchmark
-    public long iterator(LoopBenchmark.State state) {
+    public void iterator(Blackhole bh) {
-        long totalLength = 0;
+        for (Iterator<String> iterator = list.iterator(); iterator.hasNext(); ) {
-        for (Iterator<String> iterator = state.list.iterator(); iterator.hasNext(); ) {
+            bh.consume(iterator.next());
-            totalLength += iterator.next().length();
         }
-        return totalLength;
     }
 
     @Benchmark
-    public long enhancedForLoop(LoopBenchmark.State state) {
+    public void enhancedForLoop(Blackhole bh) {
-        long totalLength = 0;
+        for (String element : list) {
-        for (String element : state.list) {
+            bh.consume(element.length());
-            totalLength += element.length();
         }
-        return totalLength;
     }
 
     @Benchmark
-    public long stream(LoopBenchmark.State state) {
+    public void stream(Blackhole bh) {
-        return state.list.stream().mapToLong(String::length).sum();
+        list.stream().forEach(bh::consume);
+    }
+
+    @Benchmark
+    public void forEach(Blackhole bh) {
+        list.forEach(bh::consume);
     }
 
     public static void main(String[] args) throws RunnerException {