8289552: Make intrinsic conversions between bit representations of half precision values and floats

Reviewed-by: kvn, sviswanathan, jbhateja

test/micro/org/openjdk/bench/java/math/Fp16ConversionBenchmark.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package org.openjdk.bench.java.math;
+
+import java.util.Random;
+import java.util.concurrent.TimeUnit;
+import org.openjdk.jmh.annotations.*;
+
+@OutputTimeUnit(TimeUnit.MILLISECONDS)
+@State(Scope.Thread)
+@Warmup(iterations = 5, time = 1)
+@Measurement(iterations = 5, time = 1)
+@Fork(value = 3)
+public class Fp16ConversionBenchmark {
+
+  @Param({"2048"})
+  public int size;
+
+  public short[] f16in;
+  public short[] f16out;
+  public float[] fin;
+  public float[] fout;
+  public static short f16, s;
+  public static float f;
+
+  @Setup(Level.Trial)
+  public void BmSetup() {
+      int i = 0;
+      Random r = new Random(1024);
+
+      f16in  = new short[size];
+      f16out = new short[size];
+      f16    = (short) r.nextInt();
+
+      for (; i < size; i++) {
+          f16in[i] = Float.floatToFloat16(r.nextFloat());;
+      }
+
+      fin  = new float[size];
+      fout = new float[size];
+      f    = r.nextFloat();
+
+      i = 0;
+
+      for (; i < size; i++) {
+          fin[i] = Float.float16ToFloat((short)r.nextInt());
+      }
+  }
+
+  @Benchmark
+  public short[] floatToFloat16() {
+      for (int i = 0; i < fin.length; i++) {
+          f16out[i] = Float.floatToFloat16(fin[i]);
+      }
+      return f16out;
+  }
+
+  @Benchmark
+  public float[] float16ToFloat() {
+      for (int i = 0; i < f16in.length; i++) {
+          fout[i] = Float.float16ToFloat(f16in[i]);
+      }
+      return fout;
+  }
+
+  @Benchmark
+  public float float16ToFloatMemory() {
+      f = Float.float16ToFloat(f16);
+      return f;
+  }
+
+  @Benchmark
+  public short floatToFloat16Memory() {
+      s = Float.floatToFloat16(f);
+      return s;
+  }
+}