https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112824
Hongyu Wang <wwwhhhyyy333 at gmail dot com> changed:
What |Removed |Added
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CC| |wwwhhhyyy333 at gmail dot com
--- Comment #9 from Hongyu Wang <wwwhhhyyy333 at gmail dot com> ---
(In reply to Hongtao Liu from comment #4)
> there're 2 reasons.
> 2. There's still spills for (subreg:DF (reg: V8DF) since
> ix86_modes_tieable_p return false for DF and V8DF.
>
There could be some issue in sra that the aggregates are not properly
scalarized due to size limit.
The sra considers maximum aggregate size using move_ratio * UNITS_PER_WORD, but
here the aggregate Dual<Dual<double, 8l>, 2l> actually contains several V8DF
component that can be handled in zmm under avx512f.
Add --param sra-max-scalarization-size-Ospeed=2048 will eliminate those spills
So for sra we can consider using MOVE_MAX * move_ratio as the size limit for
Ospeed which represents real backend instruction count.
