RFR: 8345298: RISC-V: Add riscv backend for Float16 operations - scalar [v6]

[Hamlin Li]

On Wed, 12 Mar 2025 16:22:57 GMT, Robbin Ehn <rehn at openjdk.org> wrote:

>> Hamlin Li has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   refine
>
> src/hotspot/cpu/riscv/c2_MacroAssembler_riscv.cpp line 2172:
> 
>> 2170: 
>> 2171:   switch (ft) {
>> 2172:     case FLOAT_TYPE::half_precision:
> 
> I wouldn't switch three times on **ft**.
> 
> Maybe just switch once, and have all in that switch, e.g.:
> 
>     case FLOAT_TYPE::half_precision:
>       fclass_h(t0, src1);
>       fclass_h(t1, src2);
>       orr(t0, t0, t1);
>       andi(t0, t0, FClassBits::nan); // if src1 or src2 is quiet or signaling NaN then return NaN
>       fadd_h(dst, src1, src2);
>       beqz(t0, Compare);
>       j(Done);
>       bind(Compare);
>       if (is_min) {
>         fmin_h(dst, src1, src2);
>       } else {
>         fmax_h(dst, src1, src2);
>       }
>       break;
> 
> 
> No ?

Good suggestion, seems it's better.

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PR Review Comment: https://git.openjdk.org/jdk/pull/23844#discussion_r1991969494