RFR: 8263006: Add optimization for Max(*)Node and Min(*)Node [v3]
Wang Huang
whuang at openjdk.java.net
Fri Apr 23 09:07:48 UTC 2021
> * I optimize `max` and `min` by using these identities
> - op (max(a,b) , min(a,b))=== op(a,b)
> - if op is commutable
> - example :
> - max(a,b) + min(a,b))=== a + b // op = add
> - max(a,b) * min(a,b))=== a * b // op = mul
> - max( max(a,b) , min(a,b)))=== max(a,b) // op = max()
> - min( max(a,b) , min(a,b)))=== max(a,b) // op = min()
> * Test case
> ```java
> /*
> * Copyright (c) 2021, Huawei Technologies Co. Ltd. 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.sample;
>
> import org.openjdk.jmh.annotations.Benchmark;
> import org.openjdk.jmh.annotations.*;
>
> import java.util.Random;
> import java.util.concurrent.TimeUnit;
> import org.openjdk.jmh.infra.Blackhole;
>
> @BenchmarkMode({Mode.AverageTime})
> @OutputTimeUnit(TimeUnit.MICROSECONDS)
> public class MyBenchmark {
>
> static int length = 100000;
> static double[] data1 = new double[length];
> static double[] data2 = new double[length];
> static Random random = new Random();
>
> static {
> for(int i = 0; i < length; ++i) {
> data1[i] = random.nextDouble();
> data2[i] = random.nextDouble();
> }
> }
>
> @Benchmark
> public void testAdd(Blackhole bh) {
> double sum = 0;
> for (int i = 0; i < length; i++) {
> sum += Math.max(data1[i], data2[i]) + Math.min(data1[i], data2[i]);
> }
> bh.consume(sum);
> }
>
> @Benchmark
> public void testMax(Blackhole bh) {
> double sum = 0;
> for (int i = 0; i < length; i++) {
> sum += Math.max(Math.max(data1[i], data2[i]), Math.min(data1[i], data2[i]));
> }
> bh.consume(sum);
> }
>
> @Benchmark
> public void testMin(Blackhole bh) {
> double sum = 0;
> for (int i = 0; i < length; i++) {
> sum += Math.min(Math.max(data1[i], data2[i]), Math.min(data1[i], data2[i]));
> }
> bh.consume(sum);
> }
>
> @Benchmark
> public void testMul(Blackhole bh) {
> double sum = 0;
> for (int i = 0; i < length; i++) {
> sum += (Math.max(data1[i], data2[i]) * Math.min(data1[i], data2[i]));
> }
> bh.consume(sum);
> }
> }
> ```
>
> * The result is listed here (aarch64):
>
> before:
>
> |Benchmark| Mode| Samples| Score| Score error| Units|
> |---| ---| ---| ---| --- | ---|
> |o.s.MyBenchmark.testAdd |avgt | 10 | 556.048 | 32.368 | us/op |
> | o.s.MyBenchmark.testMax | avgt | 10 |543.065 | 54.221 | us/op |
> | o.s.MyBenchmark.testMin | avgt |10 |570.731 | 37.630 | us/op |
> | o.s.MyBenchmark.testMul | avgt | 10 | 531.906 | 20.518 | us/op |
>
> after:
>
> |Benchmark| Mode| Samples| Score| Score error| Units|
> |---| ---| ---| ---| --- | ---|
> | o.s.MyBenchmark.testAdd | avgt | 10 | 319.350 | 9.248 | us/op |
> | o.s.MyBenchmark.testMax | avgt | 10 | 356.138 | 10.736 | us/op |
> | o.s.MyBenchmark.testMin | avgt | 10 | 323.731 | 16.621 | us/op |
> | o.s.MyBenchmark.testMul | avgt | 10 | 338.458 | 23.755 | us/op |
>
> * I have tested `NaN` ` INFINITY` and `-INFINITY` and got same result (before/after)
Wang Huang has updated the pull request incrementally with one additional commit since the last revision:
fix bugs & add test case
-------------
Changes:
- all: https://git.openjdk.java.net/jdk/pull/3513/files
- new: https://git.openjdk.java.net/jdk/pull/3513/files/7579586f..8aef3596
Webrevs:
- full: https://webrevs.openjdk.java.net/?repo=jdk&pr=3513&range=02
- incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=3513&range=01-02
Stats: 211 lines in 3 files changed: 209 ins; 0 del; 2 mod
Patch: https://git.openjdk.java.net/jdk/pull/3513.diff
Fetch: git fetch https://git.openjdk.java.net/jdk pull/3513/head:pull/3513
PR: https://git.openjdk.java.net/jdk/pull/3513
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