RFR: 8316704: Regex-free parsing of Formatter and FormatProcessor specifiers [v17]

[温绍锦]

> @cl4es made performance optimizations for the simple specifiers of String.format in PR https://github.com/openjdk/jdk/pull/2830. Based on the same idea, I continued to make improvements. I made patterns like %2d %02d also be optimized.
> 
> The following are the test results based on MacBookPro M1 Pro: 
> 
> 
> -Benchmark                          Mode  Cnt     Score     Error  Units
> -StringFormat.complexFormat         avgt   15  1862.233 ? 217.479  ns/op
> -StringFormat.int02Format           avgt   15   312.491 ?  26.021  ns/op
> -StringFormat.intFormat             avgt   15    84.432 ?   4.145  ns/op
> -StringFormat.longFormat            avgt   15    87.330 ?   6.111  ns/op
> -StringFormat.stringFormat          avgt   15    63.985 ?  11.366  ns/op
> -StringFormat.stringIntFormat       avgt   15    87.422 ?   0.147  ns/op
> -StringFormat.widthStringFormat     avgt   15   250.740 ?  32.639  ns/op
> -StringFormat.widthStringIntFormat  avgt   15   312.474 ?  16.309  ns/op
> 
> +Benchmark                          Mode  Cnt    Score    Error  Units
> +StringFormat.complexFormat         avgt   15  740.626 ? 66.671  ns/op (+151.45)
> +StringFormat.int02Format           avgt   15  131.049 ?  0.432  ns/op (+138.46)
> +StringFormat.intFormat             avgt   15   67.229 ?  4.155  ns/op (+25.59)
> +StringFormat.longFormat            avgt   15   66.444 ?  0.614  ns/op (+31.44)
> +StringFormat.stringFormat          avgt   15   62.619 ?  4.652  ns/op (+2.19)
> +StringFormat.stringIntFormat       avgt   15   89.606 ? 13.966  ns/op (-2.44)
> +StringFormat.widthStringFormat     avgt   15   52.462 ? 15.649  ns/op (+377.95)
> +StringFormat.widthStringIntFormat  avgt   15  101.814 ?  3.147  ns/op (+206.91)

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

  move testcase from BasicInt to Basic-X

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/15776/files
  - new: https://git.openjdk.org/jdk/pull/15776/files/7a1cd112..134f2b22

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15776&range=16
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15776&range=15-16

  Stats: 12 lines in 2 files changed: 6 ins; 6 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/15776.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15776/head:pull/15776

PR: https://git.openjdk.org/jdk/pull/15776