This is an archive of the discontinued LLVM Phabricator instance.

[X86][Costmodel] Load/store i16 Stride=3 VF=8 interleaving costs
ClosedPublic

Authored by lebedev.ri on Oct 3 2021, 5:36 AM.

Details

Summary

The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3

For load we have:
https://godbolt.org/z/Mh9MnnT8W - for intels Block RThroughput: =9.0; for ryzens, Block RThroughput: <=2.3
So pick cost of 9.

For store we have:
https://godbolt.org/z/Mh9MnnT8W - for intels Block RThroughput: <=12.0; for ryzens, Block RThroughput: <=3.3
So pick cost of 12.

I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.

Diff Detail