Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Fixed AVX planner not using prime butterflies as bases #46

Merged
merged 2 commits into from
Jan 5, 2021
Merged

Fixed AVX planner not using prime butterflies as bases #46

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
6a517cf
Fixed AVX planner not using prime butterflies as bases
ejmahler Jan 5, 2021
1e5d22d
rustfmt
ejmahler Jan 5, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions benches/bench_rustfft.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -101,6 +101,7 @@ fn bench_planned_f32(b: &mut Bencher, len: usize) {
#[bench] fn planned32_composite_024028(b: &mut Bencher) { bench_planned_f32(b, 24028); }

// small mixed composites times a large prime
#[bench] fn planned32_composite_005472(b: &mut Bencher) { bench_planned_f32(b, 5472); }
#[bench] fn planned32_composite_030270(b: &mut Bencher) { bench_planned_f32(b, 30270); }

// small mixed composites
Expand Down
14 changes: 12 additions & 2 deletions src/avx/avx_planner.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -259,6 +259,11 @@ impl<T: FftNum> AvxPlannerInternal<f32, T> {
if factors.get_other_factors() > 1 {
let other_factors = factors.get_other_factors();

// First, if the "other factors" are a butterfly, use that as the butterfly
if self.is_butterfly(other_factors) {
return MixedRadixPlan::butterfly(other_factors, vec![]);
}

// We can only use rader's if `other_factors` is prime
if miller_rabin(other_factors as u64) {
// len is prime, so we can use Rader's Algorithm as a base. Whether or not that's a good idea is a different story
Expand All @@ -267,7 +272,7 @@ impl<T: FftNum> AvxPlannerInternal<f32, T> {
// We're intentionally being too conservative here. Otherwise we'd be recursively applying a heuristic, and repeated heuristic failures could stack to make a rader's chain significantly slower.
// If we were writing a measuring planner, expanding this heuristic and measuring its effectiveness would be an opportunity for up to 2x performance gains.
let inner_factors = PartialFactors::compute(other_factors - 1);
if inner_factors.get_other_factors() == 1 {
if self.is_butterfly(inner_factors.get_other_factors()) {
// We only have factors of 2,3,5,7, and 11. If we don't have AVX2, we also have to exclude factors of 5 and 7 and 11, because avx2 gives us enough headroom for the overhead of those to not be a problem
if is_x86_feature_detected!("avx2")
|| (inner_factors.product_power2power3() == len - 1)
Expand Down Expand Up @@ -464,6 +469,11 @@ impl<T: FftNum> AvxPlannerInternal<f64, T> {
if factors.get_other_factors() > 1 {
let other_factors = factors.get_other_factors();

// First, if the "other factors" are a butterfly, use that as the butterfly
if self.is_butterfly(other_factors) {
return MixedRadixPlan::butterfly(other_factors, vec![]);
}

// We can only use rader's if `other_factors` is prime
if miller_rabin(other_factors as u64) {
// len is prime, so we can use Rader's Algorithm as a base. Whether or not that's a good idea is a different story
Expand All @@ -472,7 +482,7 @@ impl<T: FftNum> AvxPlannerInternal<f64, T> {
// We're intentionally being too conservative here. Otherwise we'd be recursively applying a heuristic, and repeated heuristic failures could stack to make a rader's chain significantly slower.
// If we were writing a measuring planner, expanding this heuristic and measuring its effectiveness would be an opportunity for up to 2x performance gains.
let inner_factors = PartialFactors::compute(other_factors - 1);
if inner_factors.get_other_factors() == 1 {
if self.is_butterfly(inner_factors.get_other_factors()) {
// We only have factors of 2,3,5,7, and 11. If we don't have AVX2, we also have to exclude factors of 5 and 7 and 11, because avx2 gives us enough headroom for the overhead of those to not be a problem
if is_x86_feature_detected!("avx2")
|| (inner_factors.product_power2power3() == len - 1)
Expand Down