Re: [RFC] ifcvt: Account for parallelism when costing noce sequences

> On Aug 13, 2026, at 18:46, wangjue <[email protected]> wrote:
> 
...
> I instrumented the draft and built all SPEC CPU2017 Integer rate
> benchmarks on RISC-V.  I have not collected data for other targets yet.
> 
> The analysis succeeded in 16,947 of 30,120 invocations (56.26%).
> These calls came from 423 compiler processes.  Among the successful
> analyses, 15,024 cases (88.65%) produced a lower cost.
> 
> The parallel_cost / serial_cost histogram, using successful analyses
> as the denominator, is:
>  1.0 >= ratio > 0.8: 1,955 (11.54%)
>  0.8 >= ratio > 0.6: 8,017 (47.31%)
>  0.6 >= ratio > 0.4: 6,820 (40.24%)
>  0.4 >= ratio > 0.2:   155 ( 0.91%)
>  0.2 >= ratio > 0.0:     0 ( 0.00%)

This is great data!  Please add it for future reference somewhere in the patch, e.g., in the comment for noce_parallel_seq_cost().

This addresses all my review comments, thanks!  

--
Maxim Kuvyrkov
Garden City Compilers