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Make gaugefixing for svd_full and eigh GPU friendly #307

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Merged
kshyatt merged 5 commits into from
Oct 14, 2026
Merged

Make gaugefixing for svd_full and eigh GPU friendly #307

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2731e4b
Make gaugefixing for svd_full and eigh GPU friendly
kshyatt Oct 13, 2026
5447106
Update src/common/gauge.jl
kshyatt Oct 13, 2026
d855454
Update gauge.jl
kshyatt Oct 13, 2026
19fe0c8
Seed rng for V in eig test
kshyatt Oct 13, 2026
eae633c
Fixup eig(h)
kshyatt Oct 13, 2026
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39 changes: 18 additions & 21 deletions src/common/gauge.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -36,32 +36,29 @@ function gaugefix!(::typeof(lq_householder!), L, Q, Ld)
end

function gaugefix!(::Union{typeof(eig_full!), typeof(eigh_full!), typeof(gen_eig_full!)}, V::AbstractMatrix)
for j in axes(V, 2)
v = view(V, :, j)
s = sign(_argmaxabs(v))
@inbounds v .*= conj(s)
end
signs = reduce(_largest, V; dims = 1, init = zero(eltype(V)))
@. signs = sign(signs)
@. V = V * conj(signs)
return V
end

# TODO: can do the multiplication @. Vᴴk = signs_t * Vᴴk in one fell swoop
# earlier, or compute signs in the n > m case entirely with reference to V?
# This might require modifying forward-mode AD rules.
function gaugefix!(::typeof(svd_full!), U, Vᴴ)
m, n = size(U, 2), size(Vᴴ, 1)
for j in 1:max(m, n)
if j <= min(m, n)
u = view(U, :, j)
v = view(Vᴴ, j, :)
s = sign(_argmaxabs(u))
u .*= conj(s)
v .*= s
elseif j <= m
u = view(U, :, j)
s = sign(_argmaxabs(u))
u .*= conj(s)
else
v = view(Vᴴ, j, :)
s = sign(_argmaxabs(v))
v .*= conj(s)
end
k = min(m, n)
signs = reduce(_largest, U; dims = 1, init = zero(eltype(U)))
@. signs = sign(signs)
@. U = U * conj(signs)
Vᴴk = view(Vᴴ, axes(Vᴴ, 1)[1:k], :)
signs_t = transpose(view(signs, :, axes(signs, 2)[1:k]))
@. Vᴴk = signs_t * Vᴴk
if n > m
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Vᴴr = view(Vᴴ, axes(Vᴴ, 1)[(k + 1):n], :)
signs_r = reduce(_largest, Vᴴr; dims = 2, init = zero(eltype(Vᴴ)))
@. signs_r = sign(signs_r)
@. Vᴴr = conj(signs_r) * Vᴴr
end
return (U, Vᴴ)
end
Expand Down
4 changes: 2 additions & 2 deletions test/testsuite/decompositions/eig.jl
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Expand Up @@ -117,7 +117,7 @@ function test_eig_trunc(

m4 = 4
atol = sqrt(eps(real(eltype(T))))
V = T <: Diagonal ? I : randn!(similar(A, eltype(T), m4, m4))
V = instantiate_matrix(T, (m4, m4))
Ddiag = similar(A, real(eltype(T)), m4)
copyto!(Ddiag, real(eltype(T))[0.9, 0.3, 0.1, 0.01])
D = Diagonal(Ddiag)
Expand Down Expand Up @@ -158,7 +158,7 @@ function test_eig_trunc_algs(

m4 = 4
atol = sqrt(eps(real(eltype(T))))
V = T <: Diagonal ? I : randn!(similar(A, eltype(T), m4, m4))
V = instantiate_matrix(T, (m4, m4))
Ddiag = similar(A, real(eltype(T)), m4)
copyto!(Ddiag, real(eltype(T))[0.9, 0.3, 0.1, 0.01])
D = Diagonal(Ddiag)
Expand Down
4 changes: 2 additions & 2 deletions test/testsuite/decompositions/eigh.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -122,7 +122,7 @@ function test_eigh_trunc(
@testset "specify truncation algorithm" begin
atol = sqrt(eps(real(eltype(T))))
m4 = 4
smallA = randn!(similar(A, (m4, m4)))
smallA = instantiate_matrix(T, (m4, m4))
V = T <: Diagonal ? I : qr_compact(smallA)[1]
Ddiag = similar(A, real(eltype(T)), m4)
copyto!(Ddiag, real(eltype(T))[0.9, 0.3, 0.1, 0.01])
Expand Down Expand Up @@ -161,7 +161,7 @@ function test_eigh_trunc_algs(
# truncrank
atol = sqrt(eps(real(eltype(T))))
m4 = 4
smallA = randn!(similar(A, (m4, m4)))
smallA = instantiate_matrix(T, (m4, m4))
V = T <: Diagonal ? I : qr_compact(smallA)[1]
Ddiag = similar(A, real(eltype(T)), m4)
copyto!(Ddiag, real(eltype(T))[0.9, 0.3, 0.1, 0.01])
Expand Down
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