RFR: 8310929: Optimization for Integer.toString [v5]

[温绍锦]

> Speed up Integer.toString with a precomputed cache array of length 1000, use division by 1000, so that each iteration can calculate three digits.  
> 
> this optimization can also be used in StringBuilder#appent(int) and Long#toString.
> 
> # Benchmark Result
> 
> 
> bash configure --with-jmh=build/jmh/jars
> make test TEST="micro:java.lang.Integers.toString*"
> 
> 
> ## 1. [aliyun_ecs_c8i.xlarge](https://help.aliyun.com/document_detail/25378.html#c8i)
> * cpu : intel xeon sapphire rapids (x64)
> ``` diff
> -Benchmark               (size)  Mode  Cnt  Score   Error  Units (baseline)
> -Integers.toStringBig       500  avgt   15  6.811 ± 0.016  us/op
> -Integers.toStringSmall     500  avgt   15  4.794 ± 0.011  us/op
> -Integers.toStringTiny      500  avgt   15  3.752 ± 0.065  us/op
> 
> +Benchmark               (size)  Mode  Cnt  Score   Error  Units (PR Update 01 3355d211)
> +Integers.toStringBig       500  avgt   15  5.148 ± 0.044  us/op (+32.30%)
> +Integers.toStringSmall     500  avgt   15  3.820 ± 0.016  us/op (+25.48%)
> +Integers.toStringTiny      500  avgt   15  3.426 ± 0.010  us/op (+9.51%)
> 
> +Benchmark               (size)  Mode  Cnt  Score   Error  Units (PR Update 02 62b499d6)
> +Integers.toStringBig       500  avgt   15  5.971 ± 0.014  us/op (+14.06%)
> +Integers.toStringSmall     500  avgt   15  4.346 ± 0.016  us/op (+10.30%)
> +Integers.toStringTiny      500  avgt   15  3.671 ± 0.019  us/op (+2.20%)
> 
> 
> ## 2. [aliyun_ecs_c8a.xlarge](https://help.aliyun.com/document_detail/25378.html#c8a)
> * cpu : amd epc genoa (x64)
> ``` diff
> -Benchmark               (size)  Mode  Cnt  Score   Error  Units (baseline)
> -Integers.toStringBig       500  avgt   15  6.762 ± 0.018  us/op
> -Integers.toStringSmall     500  avgt   15  4.481 ± 0.004  us/op
> -Integers.toStringTiny      500  avgt   15  2.761 ± 0.012  us/op
> 
> +Benchmark               (size)  Mode  Cnt  Score   Error  Units (PR Update 01 3355d211)
> +Integers.toStringBig       500  avgt   15  4.901 ± 0.005  us/op (+37.97%)
> +Integers.toStringSmall     500  avgt   15  3.515 ± 0.204  us/op (+27.48%)
> +Integers.toStringTiny      500  avgt   15  2.698 ± 0.190  us/op (+2.33%)
> 
> +Benchmark               (size)  Mode  Cnt  Score   Error  Units  (PR Update 02 62b499d6)
> +Integers.toStringBig       500  avgt   15  5.493 ± 0.007  us/op (+23.10%)
> +Integers.toStringSmall     500  avgt   15  3.714 ± 0.006  us/op (+20.65%)
> +Integers.toStringTiny      500  avgt   15  2.786 ± 0.015  us/op (-0.89%)
> 
> 
> 
> ## 3. [aliyun_ecs_c8y.xlarge](https://help.aliyun.com/document_detail/25378.html#c8y)
> * ...

温绍锦 has updated the pull request incrementally with one additional commit since the last revision:

  optimization for :
  Integer#toString
  Long#toString
  StringBuilder#append(int)

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/14699/files
  - new: https://git.openjdk.org/jdk/pull/14699/files/484acc69..f4aa1989

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14699&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14699&range=03-04

  Stats: 111 lines in 3 files changed: 61 ins; 29 del; 21 mod
  Patch: https://git.openjdk.org/jdk/pull/14699.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14699/head:pull/14699

PR: https://git.openjdk.org/jdk/pull/14699