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https://github.com/engineeringsoftware/jog
Pattern-Based Peephole Optimizations with Java JIT Tests
https://github.com/engineeringsoftware/jog
compiler java jit jit-compiler openjdk optimization pattern peephole shadow test
Last synced: 3 months ago
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Pattern-Based Peephole Optimizations with Java JIT Tests
- Host: GitHub
- URL: https://github.com/engineeringsoftware/jog
- Owner: EngineeringSoftware
- License: apache-2.0
- Created: 2023-05-10T16:47:41.000Z (over 1 year ago)
- Default Branch: master
- Last Pushed: 2024-04-25T06:32:19.000Z (8 months ago)
- Last Synced: 2024-09-30T13:41:37.838Z (3 months ago)
- Topics: compiler, java, jit, jit-compiler, openjdk, optimization, pattern, peephole, shadow, test
- Language: Java
- Homepage:
- Size: 182 KB
- Stars: 7
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# JOG
JOG is a framework that facilitates developing Java JIT peephole
optimizations. JOG enables developers to write a pattern, in Java
itself, that specifies desired code transformations by writing code
before and after the optimization, as well as any necessary
preconditions. Such patterns can be written in the same way that tests
of the optimization are already written in OpenJDK. JOG translates
each pattern into C/C++ code that can be integrated as a JIT
optimization pass. JOG also generates Java tests for optimizations
from patterns. Furthermore, JOG can automatically detect possible
shadow relation between a pair of optimizations where the effect of
the shadowed optimization is overridden by another.
## Table of contents
1. [Requirements](#Requirements)
2. [Example](#Example)
3. [Hall of Fame](#Hall-of-Fame)
4. [Citation](#Citation)
5. [Contact](#Contact)
## Requirements
- Linux with GNU Bash (tested on Ubuntu 20.04 with GNU Bash 5.0.17(1)-release (x86_64-pc-linux-gnu))
- JDK >=11
We also provide a docker image with pre-built OpenJDK and cloned `jog`
repository.
```bash
docke pull zzqut/jog:latest
```
## Example
Developers write Java JIT peephole optimizations in _patterns_, using
JOG's DSL fully embedded in Java. For example, `Example.java` contains
two patterns `ADD2` and `ADD7`. `ADD2` represents a peephole
optimization that transforms `(a - b) + (c - d)` to `(a + c) - (b +
d)`, and `ADD7` expresses a peephole optimization that transforms
`(a - b) + (b - c)` to `(a - c)`.
```java
import jog.api.*;
import static jog.api.Action.*;
public class Example {
@Pattern
public void ADD2(long a, long b, long c, long d) {
before((a - b) + (c - d));
after((a + c) - (b + d));
}
@Pattern
public void ADD7(long a, long b, long c) {
before((a - b) + (b - c));
after(a - c);
}
}
```
From the patterns, JOG
1. Generates C/C++ code that can be integrated as JIT optimization
pass.
JOG translates every pattern into corresponding optimization pass
in C/C++.
`gen-code/addnode.cpp`
```cpp
/* Automatically generated by jog from patterns:
ADD2,
ADD7. */
Node* AddLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
// ADD2
{
Node* _JOG_in1 = in(1);
Node* _JOG_in11 = _JOG_in1 != NULL && 1 < _JOG_in1->req() ? _JOG_in1->in(1) : NULL;
Node* _JOG_in12 = _JOG_in1 != NULL && 2 < _JOG_in1->req() ? _JOG_in1->in(2) : NULL;
Node* _JOG_in2 = in(2);
Node* _JOG_in21 = _JOG_in2 != NULL && 1 < _JOG_in2->req() ? _JOG_in2->in(1) : NULL;
Node* _JOG_in22 = _JOG_in2 != NULL && 2 < _JOG_in2->req() ? _JOG_in2->in(2) : NULL;
if (_JOG_in1->Opcode() == Op_SubL
&& _JOG_in2->Opcode() == Op_SubL) {
return new SubLNode(phase->transform(new AddLNode(_JOG_in11, _JOG_in21)), phase->transform(new AddLNode(_JOG_in12, _JOG_in22)));
}
}
// ADD7
{
Node* _JOG_in1 = in(1);
Node* _JOG_in11 = _JOG_in1 != NULL && 1 < _JOG_in1->req() ? _JOG_in1->in(1) : NULL;
Node* _JOG_in12 = _JOG_in1 != NULL && 2 < _JOG_in1->req() ? _JOG_in1->in(2) : NULL;
Node* _JOG_in2 = in(2);
Node* _JOG_in21 = _JOG_in2 != NULL && 1 < _JOG_in2->req() ? _JOG_in2->in(1) : NULL;
Node* _JOG_in22 = _JOG_in2 != NULL && 2 < _JOG_in2->req() ? _JOG_in2->in(2) : NULL;
if (_JOG_in1->Opcode() == Op_SubL
&& _JOG_in2->Opcode() == Op_SubL
&& _JOG_in12 == _JOG_in21) {
return new SubLNode(_JOG_in11, _JOG_in22);
}
}
}
```
2. Generates Java tests that can be used to test such optimizations.
The IR test, written in Java using
[IR test framework](https://github.com/openjdk/jdk/tree/master/test/hotspot/jtreg/compiler/lib/ir_framework),
is a recommended approach in OpenJDK to testing JIT peephole
optimizations. JOG can automatically generate a IR test from every
pattern.
`gen-tests/TestAddLNode.java`
```java
/*Automatically generated by jog from patterns:
ADD2,
ADD7.*/
package compiler.c2.irTests;
import jdk.test.lib.Asserts;
import compiler.lib.ir_framework.*;
/*@test
@library /test/lib /
@run driver compiler.c2.irTests.TestAddLNode*/
public class TestAddLNode {
public static void main(String[] args) {
TestFramework.run();
}
@Run(test = { "testADD2", "testADD7" })
public void runMethod() {
long a = RunInfo.getRandom().nextLong();
long b = RunInfo.getRandom().nextLong();
long c = RunInfo.getRandom().nextLong();
long d = RunInfo.getRandom().nextLong();
long min = Long.MIN_VALUE;
long max = Long.MAX_VALUE;
assertResult(0, 0, 0, 0);
assertResult(a, b, c, d);
assertResult(min, min, min, min);
assertResult(max, max, max, max);
}
@DontCompile
public void assertResult(long a, long b, long c, long d) {
Asserts.assertEQ((a - b) + (c - d), testADD2(a, b, c, d));
Asserts.assertEQ((a - b) + (b - c), testADD7(a, b, c));
}
// Checks (a - b) + (c - d) => (a + c) - (b + d)
@Test
@IR(counts = { IRNode.ADD, "2", IRNode.SUB, "1" })
public long testADD2(long a, long b, long c, long d) {
return (a - b) + (c - d);
}
// Checks (a - b) + (b - c) => a - c
@Test
@IR(failOn = { IRNode.ADD })
@IR(counts = { IRNode.SUB, "1" })
public long testADD7(long a, long b, long c) {
return (a - b) + (b - c);
}
}
```
3. Detects any possible shadow relation between a pair of
optimizations.
Note that any expression matching `(a - b) + (c - a)` (`ADD2`) also
matches `(a - b) + (b - c)` (`ADD7`), which means `ADD2` can be
applied wherever `ADD7` can be applied, so the effect of `ADD2`
will shadow `ADD7` if `ADD2` is always applied before `ADD7` in a
compiler pass. JOG can automatically report the shadow relations.
`shadows.yml`
```yaml
-
shadowing:
name: ADD2
before: "(a - b) + (c - d)"
precondition: []
shadowed:
-
name: ADD7
before: "(a - b) + (b - c)"
precondition: []
```
To run the example, please run `./demo.sh`:
```bash
$ ./demo.sh
Building JOG...
Reading the patterns from file Example.java...
See gen-code/ for generated compiler pass in C/C++.
See gen-tests/ for generated JIT optimization tests in Java.
Shadow relations:
Pattern ADD2 shadows ADD7
```
# Hall Of Fame
Here is the list of pull requests we opened for OpenJDK:
New optimizations:
- [#6441](https://github.com/openjdk/jdk/pull/6441):
8277882: New subnode ideal optimization: converting "c0 - (x + c1)"
into "(c0 - c1) - x".
- [#6675](https://github.com/openjdk/jdk/pull/6675):
8278114: New addnode ideal optimization: converting "x + x" into "x
<< 1".
- [#6858](https://github.com/openjdk/jdk/pull/6858):
8279607: Existing optimization "~x+1" -> "- x" can be generalized to
"~x+c" -> "(c-1)-x".
- [#7795](https://github.com/openjdk/jdk/pull/7795):
8283094: Add Ideal transformation: x + (con - y) -> (x - y) + con.
- [#7376](https://github.com/openjdk/jdk/pull/7376):
8281453: New optimization: convert ~x into -1-x when ~x is used in
an arithmetic expression.
- [#7395](https://github.com/openjdk/jdk/pull/7395):
8281518: New optimization: convert "(x|y)-(x^y)" into "x&y".
- [#16333](https://github.com/openjdk/jdk/pull/16333):
Add Ideal transformation: (~a) & (~b) => ~(a | b)
- [#16334](https://github.com/openjdk/jdk/pull/16334):
Add Ideal transformation: (~a) | (~b) => ~(a & b)
New tests:
- [#11049](https://github.com/openjdk/jdk/pull/11049):
8297384: Add IR tests for existing idealizations of arithmetic
nodes.
Fix detected shadowed optimizations:
- [#6752](https://github.com/openjdk/jdk/pull/6752):
8278471: Remove unreached rules in AddNode::IdealIL.
## Citation
If you use JOG in your research, please cite our [ISSTA'23
paper](https://cptgit.github.io/dl/papers/zang23jog.pdf) and [ICSE'24 Demo paper](https://zzqpro.net/dl/papers/zang24jogtool.pdf).
```bibtex
@inproceedings{zang23jog,
author = {Zang, Zhiqiang and Thimmaiah, Aditya and Gligoric, Milos},
title = {Pattern-Based Peephole Optimizations with {J}ava {JIT} Tests},
booktitle = {International Symposium on Software Testing and Analysis},
pages = {64--75},
year= {2023},
doi = {10.1145/3597926.3598038},
}
@inproceedings{zang24jogtool,
title = {{JOG}: Java {JIT} Peephole Optimizations and Tests from Patterns},
author = {Zang, Zhiqiang and Thimmaiah, Aditya and Gligoric, Milos},
booktitle = {International Conference on Software Engineering, Tool Demonstrations Track},
pages = {to apear},
year= {2024},
doi = {10.1145/3639478.3640040}
}
```
## Contact
Let me ([Zhiqiang Zang](https://github.com/CptGit)) know if you have
any questions.