RFR: 8338694: x86_64 intrinsic for tanh using libm [v12]

[Vladimir Kozlov]

On Thu, 19 Sep 2024 21:15:11 GMT, Srinivas Vamsi Parasa <duke at openjdk.org> wrote:

>> The goal of this PR is to implement an x86_64 intrinsic for java.lang.Math.tanh() using libm
>> 
>> Benchmark (ops/ms) | Stock JDK | Tanh intrinsic | Speedup
>> -- | -- | -- | --
>> MathBench.tanhDouble | 70900 | 95618 | 1.35x
>
> Srinivas Vamsi Parasa has updated the pull request incrementally with one additional commit since the last revision:
> 
>   fix is_intrinsic_supported to work properly

Looks good. I have only one nitpick. I will start testing.

src/hotspot/share/c1/c1_Compiler.cpp line 170:

> 168:   case vmIntrinsics::_dcos:
> 169:   case vmIntrinsics::_dtan:
> 170:   #if defined(X86)

Use `#ifdef AMD64` for x64 only

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PR Review: https://git.openjdk.org/jdk/pull/20657#pullrequestreview-2323102058
PR Review Comment: https://git.openjdk.org/jdk/pull/20657#discussion_r1771949759