Skip to content

Keep broadcasts over views of dense arrays sparse #772

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

Merged
ViralBShah merged 2 commits into from
Sep 9, 2026
Merged

Keep broadcasts over views of dense arrays sparse #772

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
5b4df74
Keep broadcasts over views of dense arrays sparse
ViralBShah Sep 8, 2026
369611a
Use `parent(t)` rather than `t.parent` for Transpose and Adjoint
ViralBShah Sep 9, 2026
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
3 changes: 2 additions & 1 deletion src/higherorderfns.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -94,7 +94,8 @@ is_supported_sparse_broadcast(::AbstractArray, rest...) = false
is_supported_sparse_broadcast(::AbstractSparseArray, rest...) = is_supported_sparse_broadcast(rest...)
is_supported_sparse_broadcast(::StructuredMatrix, rest...) = is_supported_sparse_broadcast(rest...)
is_supported_sparse_broadcast(::Array, rest...) = is_supported_sparse_broadcast(rest...)
is_supported_sparse_broadcast(t::Union{Transpose, Adjoint}, rest...) = is_supported_sparse_broadcast(t.parent, rest...)
is_supported_sparse_broadcast(t::Union{Transpose, Adjoint}, rest...) = is_supported_sparse_broadcast(parent(t), rest...)
is_supported_sparse_broadcast(v::SubArray, rest...) = is_supported_sparse_broadcast(parent(v), rest...)
is_supported_sparse_broadcast(x, rest...) = axes(x) === () && is_supported_sparse_broadcast(rest...)
is_supported_sparse_broadcast(x::Ref, rest...) = is_supported_sparse_broadcast(rest...)

Expand Down
28 changes: 28 additions & 0 deletions test/higherorderfns.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -435,6 +435,34 @@ end
@test A .+ ntuple(identity, N) isa Matrix
end

@testset "broadcast[!] over views of dense and sparse arrays (#508)" begin
N, p = 10, 0.4
V = sprand(N, p)
A = sprand(N, N, p)
Z = copy(A)
C = rand(N)
M = rand(N, N)
# views of dense arrays should not force a dense result
for X in (view(M, :, :), view(M, 1:N, 1:N), view(M, collect(1:N), :), view(M, :, :)')
fX = Array(X)
@test broadcast(+, A, X)::SparseMatrixCSC == sparse(broadcast(+, Array(A), fX))
@test broadcast(*, A, X)::SparseMatrixCSC == sparse(broadcast(*, Array(A), fX))
@test broadcast!(*, Z, A, X) == sparse(broadcast(*, Array(A), fX))
# the structural zeros of A must be preserved by a zero-preserving op
@test nnz(broadcast(*, A, X)) <= nnz(A)
end
for x in (view(C, :), view(C, 1:N), view(C, collect(1:N)))
@test broadcast(*, V, x)::SparseVector == sparse(broadcast(*, Array(V), Array(x)))
@test nnz(broadcast(*, V, x)) <= nnz(V)
end
# views of sparse arrays likewise
S = sprand(N, 2N, p)
@test broadcast(*, A, view(S, :, 1:N))::SparseMatrixCSC ==
sparse(broadcast(*, Array(A), Array(S[:, 1:N])))
# a view of an unsupported array still diverts to generic dense broadcast
@test broadcast(*, A, view(PermutedDimsArray(M, (2, 1)), :, :)) isa Matrix
end

@testset "map[!] over combinations of sparse and structured matrices" begin
N, p = 10, 0.4
A = sprand(N, N, p)
Expand Down
Loading