LinearAlgebra/addmul/mul!(::Matrix{BigFloat}, ::LinearAlgebra.UpperTriangular{Float64, S} where S<:AbstractMatrix{Float64}, ::LinearAlgebra.UnitUpperTriangular{Float64, S} where S<:AbstractMatrix{Float64}, α, β)/α = 0.68836506078865011826195541289052926003932952880859375, β = false/adjoint and transpose/fa = adjoint, fb = adjoint @test returned_mat === Ccopy