8343844: Add benchmarks for superword/autovectorization in FFM BulkOperations

Reviewed-by: mcimadamore

Author: minborg

test/micro/org/openjdk/bench/java/lang/foreign/SegmentBulkFill.java

@@ -38,6 +38,7 @@
 
 import java.lang.foreign.Arena;
 import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 import java.nio.ByteBuffer;
 import java.util.Arrays;
 import java.util.concurrent.TimeUnit;
@@ -74,6 +75,20 @@ public void arraysFill() {
         Arrays.fill(array, (byte) 0);
     }
 
+    @Benchmark
+    public void arraysFillLoop() {
+        for (int i = 0; i < array.length; i++) {
+            array[i] = 0;
+        }
+    }
+
+    @Benchmark
+    public void bufferFillLoop() {
+        for (int i = 0; i < array.length; i++) {
+            buffer.put(i, (byte)0);
+        }
+    }
+
     @Fork(value = 3, jvmArgs = {"-Djava.lang.foreign.native.threshold.power.fill=31"})
     @Benchmark
     public void heapSegmentFillJava() {
@@ -86,6 +101,13 @@ public void heapSegmentFillUnsafe() {
         heapSegment.fill((byte) 0);
     }
 
+    @Benchmark
+    public void heapSegmentFillLoop() {
+        for (long i = 0; i < heapSegment.byteSize(); i++) {
+            heapSegment.set(ValueLayout.JAVA_BYTE, i, (byte) 0);
+        }
+    }
+
     @Fork(value = 3, jvmArgs = {"-Djava.lang.foreign.native.threshold.power.fill=31"})
     @Benchmark
     public void nativeSegmentFillJava() {
@@ -98,6 +120,13 @@ public void nativeSegmentFillUnsafe() {
         nativeSegment.fill((byte) 0);
     }
 
+    @Benchmark
+    public void nativeSegmentFillLoop() {
+        for (long i = 0; i < nativeSegment.byteSize(); i++) {
+            nativeSegment.set(ValueLayout.JAVA_BYTE, i, (byte) 0);
+        }
+    }
+
     @Fork(value = 3, jvmArgs = {"-Djava.lang.foreign.native.threshold.power.fill=31"})
     @Benchmark
     public void unalignedSegmentFillJava() {
@@ -110,4 +139,11 @@ public void unalignedSegmentFillUnsafe() {
         unalignedSegment.fill((byte) 0);
     }
 
+    @Benchmark
+    public void unalignedSegmentFillLoop() {
+        for (long i = 0; i < unalignedSegment.byteSize(); i++) {
+            unalignedSegment.set(ValueLayout.JAVA_BYTE, i, (byte) 0);
+        }
+    }
+
 }