RFR: 8308776: [AArch64] Math.log is 10% slower than StrictMath.log on aarch64

[Emanuel Peter]

On Tue, 18 Nov 2025 20:49:33 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> This PR Introduces an optimized AArch64 intrinsic for Math.log using reciprocal refinement and a table-driven polynomial.
>> Improves throughput for double logarithms while preserving IEEE-754 corner case behavior (±0, subnormals, negatives, NaN).
>
> test/jdk/java/lang/Math/TestLogMinValue.java line 28:
> 
>> 26:  * @bug 8308776
>> 27:  * @build Tests
>> 28:  * @summary Compare Math.log and StrictMath.log for Double.MIN_VALUE (denormal smallest positive) to ensure consistency.
> 
> Are there tests that check for consistency of the other values?

Do we have tests that already check for sufficient accuracy?

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PR Review Comment: https://git.openjdk.org/jdk/pull/28306#discussion_r2539670255