--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/micro/org/openjdk/bench/vm/compiler/DivRem.java Fri Nov 16 23:39:51 2018 +0100
@@ -0,0 +1,217 @@
+/*
+ * Copyright (c) 2014 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.vm.compiler;
+
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.Setup;
+import org.openjdk.jmh.annotations.State;
+
+import java.util.Random;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Tests speed of division and remainder calculations.
+ */
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+@State(Scope.Thread)
+public class DivRem {
+
+ private static final int ARRAYSIZE = 500;
+
+ /* instance fields for the constant int division tests. */
+ public int[] intValues, intValues2;
+
+ /* instance fields for the constant long division tests. */
+ public long[] longValues, longValues2;
+
+ /* instance fields for the tests using the testdr-method. */
+ public long[] drLongValues1, drLongValues2;
+
+ public long[] drLongValuesAsInts1, drLongValuesAsInts2;
+
+ @Setup
+ public void setupSubclass() {
+ Random r = new Random(4711);
+
+ intValues = new int[ARRAYSIZE];
+ intValues2 = new int[ARRAYSIZE];
+ longValues = new long[ARRAYSIZE];
+ longValues2 = new long[ARRAYSIZE];
+
+ for (int i = 0; i < ARRAYSIZE; i++) {
+ intValues[i] = r.nextInt();
+ if (intValues[i] == 0) {
+ intValues[i] = 5353;
+ }
+ intValues2[i] = r.nextInt();
+
+ longValues[i] = r.nextLong();
+ if (longValues[i] == 0) {
+ longValues[i] = 5353L;
+ }
+ longValues2[i] = r.nextLong();
+ }
+
+ /* generate random longs for 32-64 tests */
+
+ drLongValues1 = new long[ARRAYSIZE];
+ drLongValues2 = new long[ARRAYSIZE];
+ drLongValuesAsInts1 = new long[ARRAYSIZE];
+ drLongValuesAsInts2 = new long[ARRAYSIZE];
+ for (int i = 0; i < ARRAYSIZE; i++) {
+ long l = r.nextLong();
+ if (l == 0L) {
+ l++;
+ }
+ drLongValues1[i] = l;
+ drLongValuesAsInts1[i] = (long) (int) l;
+ l = r.nextLong();
+ if (l == 0L) {
+ l++;
+ }
+ drLongValues2[i] = l;
+ drLongValuesAsInts2[i] = (long) (int) l;
+ }
+ }
+
+ /**
+ * Tests integer division with a constant divisor. Hopefully the JVM will do a Granlund-Montgomery and convert it to
+ * a multiplication instead.
+ */
+ @Benchmark
+ public int testIntDivConstantDivisor() {
+ int dummy = 0;
+ for (int i = 0; i < intValues.length; i++) {
+ dummy += intValues[i] / 49;
+ }
+ return dummy;
+ }
+
+ /**
+ * Tests long division with a constant divisor. Hopefully the JVM will do a Granlund-Montgomery and convert it to a
+ * multiplication instead.
+ */
+ @Benchmark
+ public long testLongDivConstantDivisor() {
+ long dummy = 0;
+ for (int i = 0; i < longValues.length; i++) {
+ dummy += longValues[i] / 49L + longValues[i] / 0x4949494949L;
+ }
+ return dummy;
+ }
+
+ /**
+ * Tests integer remainder with a constant divisor. Hopefully the JVM will do a Granlund-Montgomery and convert it to
+ * two multiplications instead.
+ */
+ @Benchmark
+ public int testIntRemConstantDivisor() {
+ int dummy = 0;
+ for (int i = 0; i < intValues.length; i++) {
+ dummy += intValues[i] % 49;
+ }
+ return dummy;
+ }
+
+ /**
+ * Tests long division with a constant divisor. Hopefully the JVM will do a Granlund-Montgomery and convert it to a
+ * multiplication instead.
+ */
+ @Benchmark
+ public long testLongRemConstantDivisor() {
+ long dummy = 0;
+ for (int i = 0; i < longValues.length; i++) {
+ dummy += longValues[i] % 49L + longValues[i] % 0x4949494949L;
+ }
+ return dummy;
+ }
+
+ /**
+ * Tests integer division with a variable divisor. This benchmark is mainly here to be a comparison against the
+ * benchmark that performs both divisions and remainder calculations.
+ */
+ @Benchmark
+ public int testIntDivVariableDivisor() {
+ int dummy = 0;
+ for (int i = 0; i < intValues.length; i++) {
+ dummy += intValues2[i] / intValues[i];
+ }
+ return dummy;
+ }
+
+ /**
+ * Tests integer division and remainder with a variable divisor. Both calculations are performed with the same
+ * divisor, so a JVM should not have to perform two complex calculations. Either a division followed by a
+ * multiplication, or on X86 using idiv, where the reminder is also returned from the idiv instruction.
+ */
+ @Benchmark
+ public int testIntDivRemVariableDivisor() {
+ int dummy = 0;
+ for (int i = 0; i < intValues.length; i++) {
+ dummy += intValues2[i] / intValues[i];
+ dummy += intValues2[i] % intValues[i];
+ }
+ return dummy;
+ }
+
+ @Benchmark
+ public long test64DivRem64() {
+ long dummy = 0;
+ for (int i = 0; i < drLongValues1.length; i++) {
+ long l1 = drLongValues1[i];
+ long l2 = drLongValues2[i];
+ dummy += l1 / l2;
+ dummy += l1 % l2;
+ }
+ return dummy;
+ }
+
+ @Benchmark
+ public long test32DivRem32() {
+ long dummy = 0;
+ for (int i = 0; i < drLongValuesAsInts1.length; i++) {
+ long l1 = drLongValuesAsInts1[i];
+ long l2 = drLongValuesAsInts2[i];
+ dummy += l1 / l2;
+ dummy += l1 % l2;
+ }
+ return dummy;
+ }
+
+ @Benchmark
+ public long test64DivRem32() {
+ long dummy = 0;
+ for (int i = 0; i < drLongValues1.length; i++) {
+ long l1 = drLongValues1[i];
+ long l2 = drLongValuesAsInts2[i];
+ dummy += l1 / l2;
+ dummy += l1 % l2;
+ }
+ return dummy;
+ }
+}