RFR: 8312425: [vectorapi] AArch64: Optimize vector math operations with SLEEF

[Hamlin Li]

On Wed, 3 Apr 2024 19:23:01 GMT, Magnus Ihse Bursie <ihse at openjdk.org> wrote:

> Just a quick question after giving this a glance: My understanding was that the normal libsleef build set a lot of compiler options, e.g. disabling built-in maths etc. You don't seem to set any of these. Have you determined that they were not needed?

Thanks for having a look and quick response. Good question.

Per `disabling built-in maths`, my understanding is that maybe we don't need to care about it, as this built-in math functions in compilers are only for scalar version, but we're using sleef's simd versions only which use vector intrinsics I think. e.g. in `src/libm/sleefdp.c` there is `ENABLE_BUILTIN_MATH` check, but in `src/libm/sleefsimdsp.c` there is no such check, so when generating inline header files, I assume its value (whether enable/disable built-in math) does not impact the generated simd functions. Please correct me if I'm understanding it wrongly.

For other compiler options, I tend to agree with you, but I'm not sure which might need, can you supply more information or point to some reference about `normal libsleef build`? BTW, what I refered to before was from sleef.org and sleef on github (including its github workflow).

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PR Comment: https://git.openjdk.org/jdk/pull/18605#issuecomment-2037072600