RFR: 8320500: [vectorapi] RISC-V: Optimize vector math operations with SLEEF [v8]

[Hamlin Li]

On Fri, 27 Sep 2024 02:22:58 GMT, Fei Yang <fyang at openjdk.org> wrote:

>> Hamlin Li has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   fix test macro
>
> src/jdk.incubator.vector/linux/native/libsleef/lib/vector_math_rvv.c line 51:
> 
>> 49: // the dynamic rounding mode is always RNE.
>> 50: 
>> 51: #ifdef DEBUG
> 
> Question: Should we check for `NDEBUG` macro (A macro specified by C/C++ standard) here instead? I see checks for this macro in the original SLEEF code.
> 
> 
> #ifndef NDEBUG
> #define CHECK_FRM   __asm__ __volatile__ (     \
>     "    frrm   t0              \n\t"          \
>     "    beqz   t0, 2f          \n\t"          \
>     "    csrrw  x0, cycle, x0   \n\t"          \
>     "2:                         \n\t"          \
>     : : : "memory" );
> #else
> #define CHECK_FRM
> #endif

`NDEBUG` is only used in sleefdp.c which is the original sleef code, and we don't use that file in jdk directly, in java.base module of jdk it uses `DEBUG` but not use `NDEBUG`.
Based on above information, I think `DEBUG` is better.

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PR Review Comment: https://git.openjdk.org/jdk/pull/21083#discussion_r1778114122