RFR: JDK-8302026: Port fdlibm inverse trig functions (asin, acos, atan) to Java

[Joe Darcy]

On Mon, 13 Feb 2023 22:03:14 GMT, Joe Darcy <darcy at openjdk.org> wrote:

> Proceeding down the line of FDLIBM functions to be ported, next up are asin, acos, and atan.
> 
> Diffs of the various versions will follow in a separate message.
> 
> There were no unusual coding idioms encountered in porting these methods.

> Proceeding down the line of FDLIBM functions to be ported, next up are asin, acos, and atan.
> 
> Diffs of the various versions will follow in a separate message.
> 
> There were no unusual coding idioms encountered in porting these methods.
> ### Progress
> 
>     * [ ]  Change must be properly reviewed (1 review required, with at least 1 [Reviewer](https://openjdk.org/bylaws#reviewer))
> 
>     * [x]  Change must not contain extraneous whitespace
> 
>     * [x]  Commit message must refer to an issue
> 
> 
> ### Issue
> 
>     * [JDK-8302026](https://bugs.openjdk.org/browse/JDK-8302026): Port fdlibm inverse trig functions (asin, acos, atan) to Java
> 
> 
> ### Reviewing
> Using `git`
> Using Skara CLI tools
> Using diff file

PS In one-off local testing, testing all float arguments for acos/asin/atan passed when run against both JDK 20 and JDK 21, increasing confidence that both the transliteration port is equivalent to the original C code and that the idiomatic port is equivalent to the transliteration one.

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PR: https://git.openjdk.org/jdk/pull/12545