[PATCH] D124284: [SLP]Try partial store vectorization if supported by target.

[Alina Sbirlea via Phabricator via llvm-commits]

asbirlea added a comment.

I'm seeing some fairly big regressions with this patch, specifically on Rome (AMD) architecture. 
A couple of examples that are public in the test suite: SingleSource/Benchmarks/Shootout: for sieve I'm seeing a 20% performance regression in an opt build and an xfdo one, and for MicroBenchmarks/ImageProcessing/Dither 10% regression (opt, thinlto and xfdo).
I'm seeing also a couple on Skylake, opt build, in the range of 5-13 %, an example being eigen with 13% regression; this may be harder to track down as it's in a specific configuration but let me know if you want to reproduce this one.

As far as performance improvements, I see a few on Skylake in the range of 3-6%. An example here is MicroBenchmarks/ImageProcessing/Blur, which ranges between 4-5% improvement.

Overall, the regressions outnumber the gains in the testing I've done so far and would likely block our compiler release.


Repository:
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  https://reviews.llvm.org/D124284/new/

https://reviews.llvm.org/D124284