avx vecwise butterflies

[spapinistarkware]

This change is 

[spapinistarkware]

• ColumnOps #459
• Use precomputed twiddles in avx #443
• Precompute twiddles #401
• Remove FRI PolyOps dependency #399
• avx slow eval #398
• avx poly extend #397
• AVX fft eval on larger domains #396
• Reverse order of evaluations #395
• Incorporate fft in AVX backend #394
• AVX regular fft #390
• Separate ifft #389
• Support ifft for itnermediate sizes #383
• AVX fft benchmark #382
• ifft_full #381
• Save twiddles #380
• ifft_lower #379
• avx ifft3 #378
• avx vecwise butterflies #377 👈
• avx vecwise ibutterfly #368
• avx ibutterfly #367
• avx butterfly #366
• avx poly #365
• dev

This stack of pull requests is managed by Graphite. Learn more about stacking.

Join @spapinistarkware and the rest of your teammates on Graphite

[ilyalesokhin-starkware]

src/core/backend/avx512/fft.rs line 160 at r1 (raw file):

/// Runs fft on 2 vectors of 16 M31 elements.
/// This amounts to 4 butterfly layers, each with 16 butterflies.
/// Each of the vectors represents natural ordered polynomial coefficeint.

Isn't this true only at the first layer?

Code quote:

/// Each of the vectors represents natural ordered polynomial coefficeint.

[ilyalesokhin-starkware]

src/core/backend/avx512/fft.rs line 178 at r1 (raw file):

    // TODO(spapini): The permute can be fused with the _mm512_srli_epi64 inside the butterfly.
    // The implementation is the exact reverse of vecwise_ibutterflies().
    // See the comments in its body for more info.

what body?

Code quote:

See the comments in its body for more info.

[spapinistarkware]

Reviewable status: 0 of 1 files reviewed, 2 unresolved discussions (waiting on @ilyalesokhin-starkware)

---

src/core/backend/avx512/fft.rs line 160 at r1 (raw file):

Previously, ilyalesokhin-starkware wrote…

Isn't this true only at the first layer?

Yes, and this function only runs on the first layer, or equivalently, perform a full fft on the coefficients.

---

src/core/backend/avx512/fft.rs line 178 at r1 (raw file):

Previously, ilyalesokhin-starkware wrote…

what body?

vecwise_ibutterflies()

[ilyalesokhin-starkware]

Reviewed 1 of 1 files at r1, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @spapinistarkware)

[graphite-app]

Merge activity

• Mar 4, 4:51 AM EST: spapinistarkware added this pull request to the Graphite merge queue.
• Mar 4, 4:56 AM EST: spapinistarkware merged this pull request with the Graphite merge queue.