RFR: 8302783: Improve CRC32C intrinsic with crypto pmull on AArch64
Yi-Fan Tsai
duke at openjdk.org
Fri Feb 17 20:07:16 UTC 2023
Instruction pmull and pmull2 support operating on 64-bit data in Cryptographic Extension. The execution throughput of this form raises from 1 on Neoverse N1 to 4 on Neoverse V1 while the latency remains 2. The CRC32C instructions did not changed: latency 2, throughput 1. As a result, computing CRC32C using pmull could perform better than using crc32c instruction.
The following test has passed.
test/hotspot/jtreg/compiler/intrinsics/zip/TestCRC32C.java
The throughput reported by [the micro benchmark](https://github.com/openjdk/jdk/blob/master/test/micro/org/openjdk/bench/java/util/TestCRC32C.java) is measured on an EC2 c7g instance. The optimization shows 10 - 99% improvement when the input is at least 384 bytes.
| input | 64 | 128 | 256 | 384 | 511 | 512 | 1,024 |
| ------------- | ---------- | ---------- | ---------- | ---------- | ---------- | ---------- | ---------- |
| improvement | 1.60% | 0.00% | 0.00% | 15.24% | 10.76% | 34.32% | 72.39% |
| input | 2,048 | 4,096 | 8,192 | 16,384 | 32,768 | 65,536 |
| ------------- | ---------- | ---------- | ---------- | ---------- | ---------- | ---------- |
| improvement | 84.96% | 92.59% | 96.19% | 98.02% | 99.32% | 98.36% |
Baseline
Benchmark (count) Mode Cnt Score Error Units
TestCRC32C.testCRC32CUpdate 64 thrpt 12 196575.739 ± 1824.113 ops/ms
TestCRC32C.testCRC32CUpdate 128 thrpt 12 123666.570 ± 2.730 ops/ms
TestCRC32C.testCRC32CUpdate 256 thrpt 12 70188.989 ± 2.002 ops/ms
TestCRC32C.testCRC32CUpdate 384 thrpt 12 49000.690 ± 1.421 ops/ms
TestCRC32C.testCRC32CUpdate 511 thrpt 12 34106.279 ± 25.390 ops/ms
TestCRC32C.testCRC32CUpdate 512 thrpt 12 37638.349 ± 1.039 ops/ms
TestCRC32C.testCRC32CUpdate 1024 thrpt 12 19526.513 ± 0.439 ops/ms
TestCRC32C.testCRC32CUpdate 2048 thrpt 12 9951.392 ± 4.803 ops/ms
TestCRC32C.testCRC32CUpdate 4096 thrpt 12 5023.268 ± 0.240 ops/ms
TestCRC32C.testCRC32CUpdate 8192 thrpt 12 2523.877 ± 0.062 ops/ms
TestCRC32C.testCRC32CUpdate 16384 thrpt 12 1265.011 ± 0.047 ops/ms
TestCRC32C.testCRC32CUpdate 32768 thrpt 12 632.291 ± 0.058 ops/ms
TestCRC32C.testCRC32CUpdate 65536 thrpt 12 315.396 ± 0.160 ops/ms
Crypto pmull
Benchmark (count) Mode Cnt Score Error Units
TestCRC32C.testCRC32CUpdate 64 thrpt 12 199726.599 ± 166.477 ops/ms
TestCRC32C.testCRC32CUpdate 128 thrpt 12 123669.385 ± 1.821 ops/ms
TestCRC32C.testCRC32CUpdate 256 thrpt 12 70188.727 ± 1.313 ops/ms
TestCRC32C.testCRC32CUpdate 384 thrpt 12 56468.837 ± 76.524 ops/ms
TestCRC32C.testCRC32CUpdate 511 thrpt 12 37777.205 ± 406.431 ops/ms
TestCRC32C.testCRC32CUpdate 512 thrpt 12 50554.555 ± 17.169 ops/ms
TestCRC32C.testCRC32CUpdate 1024 thrpt 12 33661.006 ± 140.471 ops/ms
TestCRC32C.testCRC32CUpdate 2048 thrpt 12 18406.482 ± 205.952 ops/ms
TestCRC32C.testCRC32CUpdate 4096 thrpt 12 9674.159 ± 20.390 ops/ms
TestCRC32C.testCRC32CUpdate 8192 thrpt 12 4951.562 ± 6.566 ops/ms
TestCRC32C.testCRC32CUpdate 16384 thrpt 12 2504.970 ± 1.883 ops/ms
TestCRC32C.testCRC32CUpdate 32768 thrpt 12 1260.278 ± 0.484 ops/ms
TestCRC32C.testCRC32CUpdate 65536 thrpt 12 625.608 ± 0.300 ops/ms
-------------
Commit messages:
- pmull CRC32C
Changes: https://git.openjdk.org/jdk/pull/12624/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12624&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8302783
Stats: 78 lines in 3 files changed: 77 ins; 0 del; 1 mod
Patch: https://git.openjdk.org/jdk/pull/12624.diff
Fetch: git fetch https://git.openjdk.org/jdk pull/12624/head:pull/12624
PR: https://git.openjdk.org/jdk/pull/12624
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