RFR: 8265783: Create a separate library for x86 Intel SVML assembly intrinsics

[Andrew Haley]

Hi, thanks. One or two points inline.

On 5/20/21 12:51 AM, Viswanathan, Sandhya wrote:

> The routines contributed to OpenJDK are high accuracy (within 1ulp) routines.

Do the routines meet the (semi-) monotonicity requirements for
Java.lang.Math?

"Therefore, most methods with more than 0.5 ulp errors are required to
be semi-monotonic: whenever the mathematical function is
non-decreasing, so is the floating-point approximation, likewise,
whenever the mathematical function is non-increasing, so is the
floating-point approximation. Not all approximations that have 1 ulp
accuracy will automatically meet the monotonicity requirements."

> The library is written using Intel C Compiler extensions.
> The generated code is the only way we could bring it in.

Sure, I understand. However, you could bring in the source code as
well. Sure, you would need the Intel C compiler to compile it, but it
would be a valuable reference for maintainers, just to help
understand.

> As part of Vector API incubation, we want to give a platform to
> application writers where they can experiment writing their
> data-parallel algorithms in Java itself.
> We hope that bringing generated assembly like this is one off as you
> mention and not something to become a practice.

I hope not. Thank you for the reply.

-- 
Andrew Haley  (he/him)
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
https://keybase.io/andrewhaley
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