RFR: 8338930: StringConcatFactory hardCoded string concatenation strategy [v2]

[Claes Redestad]

On Sun, 25 Aug 2024 12:54:08 GMT, Shaojin Wen <duke at openjdk.org> wrote:

> If the number of parameters is greater than 2, the probability of reuse may not be high. Using hard-coded constants can avoid the use of forceinline.

I think this entirely depends on the application. Too low a threshold and many applications will see an increase in number of generated classes. And perhaps we shouldn't assume _any_ high arity concatenations are performance sensitive enough that generating a class-per-call-site is ever a reasonable default. A good tunable for some applications, perhaps.

> 
> From this PR, adding hard-coded constants only requires a small change, which may be a good solution.

It's good that layering this on top of the existing strategy is relatively straightforward, yes.

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PR Comment: https://git.openjdk.org/jdk/pull/20675#issuecomment-2308831173