Dear all,
Can you do me a favor to review this patch. This patch use `ldp` to
implement String.compareTo.
* We add a JMH test case
* Here is the result of this test case
Benchmark |(size)| Mode| Cnt|Score | Error |Units
---------------------------------|------|-----|----|------|--------|-----
StringCompare.compareLL | 64 | avgt| 5 |7.992 | ± 0.005|us/op
StringCompare.compareLL | 72 | avgt| 5 |15.029| ± 0.006|us/op
StringCompare.compareLL | 80 | avgt| 5 |14.655| ± 0.011|us/op
StringCompare.compareLL | 91 | avgt| 5 |16.363| ± 0.12 |us/op
StringCompare.compareLL | 101 | avgt| 5 |16.966| ± 0.007|us/op
StringCompare.compareLL | 121 | avgt| 5 |19.276| ± 0.006|us/op
StringCompare.compareLL | 181 | avgt| 5 |19.002| ± 0.417|us/op
StringCompare.compareLL | 256 | avgt| 5 |24.707| ± 0.041|us/op
StringCompare.compareLLWithLdp| 64 | avgt| 5 |8.001 | ± 0.121|us/op
StringCompare.compareLLWithLdp| 72 | avgt| 5 |11.573| ± 0.003|us/op
StringCompare.compareLLWithLdp| 80 | avgt| 5 |6.861 | ± 0.004|us/op
StringCompare.compareLLWithLdp| 91 | avgt| 5 |12.774| ± 0.201|us/op
StringCompare.compareLLWithLdp| 101 | avgt| 5 |8.691 | ± 0.004|us/op
StringCompare.compareLLWithLdp| 121 | avgt| 5 |11.091| ± 1.342|us/op
StringCompare.compareLLWithLdp| 181 | avgt| 5 |14.64 | ± 0.581|us/op
StringCompare.compareLLWithLdp| 256 | avgt| 5 |25.879| ± 1.775|us/op
StringCompare.compareUU | 64 | avgt| 5 |13.476| ± 0.01 |us/op
StringCompare.compareUU | 72 | avgt| 5 |15.078| ± 0.006|us/op
StringCompare.compareUU | 80 | avgt| 5 |23.512| ± 0.011|us/op
StringCompare.compareUU | 91 | avgt| 5 |24.284| ± 0.008|us/op
StringCompare.compareUU | 101 | avgt| 5 |20.707| ± 0.017|us/op
StringCompare.compareUU | 121 | avgt| 5 |29.302| ± 0.011|us/op
StringCompare.compareUU | 181 | avgt| 5 |39.31 | ± 0.016|us/op
StringCompare.compareUU | 256 | avgt| 5 |54.592| ± 0.392|us/op
StringCompare.compareUUWithLdp| 64 | avgt| 5 |16.389| ± 0.008|us/op
StringCompare.compareUUWithLdp| 72 | avgt| 5 |10.71 | ± 0.158|us/op
StringCompare.compareUUWithLdp| 80 | avgt| 5 |11.488| ± 0.024|us/op
StringCompare.compareUUWithLdp| 91 | avgt| 5 |13.412| ± 0.006|us/op
StringCompare.compareUUWithLdp| 101 | avgt| 5 |16.245| ± 0.434|us/op
StringCompare.compareUUWithLdp| 121 | avgt| 5 |16.597| ± 0.016|us/op
StringCompare.compareUUWithLdp| 181 | avgt| 5 |27.373| ± 0.017|us/op
StringCompare.compareUUWithLdp| 256 | avgt| 5 |41.74 | ± 3.5 |us/op
>From this table, we can see that in most cases, our patch is better than old
>one.
Thank you for your review. Any suggestions are welcome.
-------------
Commit messages:
- 8268231: Aarch64: Use ldp in intrinsics for String.compareTo
Changes: https://git.openjdk.java.net/jdk/pull/4722/files
Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4722&range=00
Issue: https://bugs.openjdk.java.net/browse/JDK-8268231
Stats: 259 lines in 3 files changed: 255 ins; 0 del; 4 mod
Patch: https://git.openjdk.java.net/jdk/pull/4722.diff
Fetch: git fetch https://git.openjdk.java.net/jdk pull/4722/head:pull/4722
PR: https://git.openjdk.java.net/jdk/pull/4722
