Specialize transpose/adjoint for reshaped Transpose/Adjoint

Author: jishnub

src/adjtrans.jl

@@ -552,3 +552,16 @@ conj(A::Adjoint) = transpose(A.parent)
 function Base.replace_in_print_matrix(A::AdjOrTrans,i::Integer,j::Integer,s::AbstractString)
     Base.replace_in_print_matrix(parent(A), j, i, s)
 end
+
+# Special adjoint/transpose methods for Adjoint/Transpose that have been reshaped as a vector
+# these are used in transposing banded matrices by forwarding the operation to the bands
+# the permutedims converts a n-element vector to an 1xn matrix
+transpose(A::Base.ReshapedArray{<:Any,1,<:TransposeAbsVec}) = permutedims(transpose(parent(A)))
+adjoint(A::Base.ReshapedArray{<:Any,1,<:AdjointAbsVec}) = permutedims(adjoint(parent(A)))
+
+# compute vec(transpose(A)), but avoid an allocating reshape if possible
+_vectranspose(A::AbstractVector) = vec(transpose(A))
+_vectranspose(A::Base.ReshapedArray{<:Any,1,<:TransposeAbsVec}) = transpose(parent(A))
+# compute vec(adjoint(A)), but avoid an allocating reshape if possible
+_vecadjoint(A::AbstractVector) = vec(adjoint(A))
+_vecadjoint(A::Base.ReshapedArray{<:Any,1,<:AdjointAbsVec}) = adjoint(parent(A))

src/bidiag.jl

@@ -308,12 +308,8 @@ for func in (:conj, :copy, :real, :imag)
 end
 isreal(M::Bidiagonal) = isreal(M.dv) && isreal(M.ev)
 
-adjoint(B::Bidiagonal) = Bidiagonal(vec(adjoint(B.dv)), vec(adjoint(B.ev)), B.uplo == 'U' ? :L : :U)
-adjoint(B::Bidiagonal{<:Any, <:Base.ReshapedArray{<:Any,1,<:AdjointAbsVec}}) =
-    Bidiagonal(adjoint(parent(B.dv)), adjoint(parent(B.ev)), B.uplo == 'U' ? :L : :U)
-transpose(B::Bidiagonal) = Bidiagonal(vec(transpose(B.dv)), vec(transpose(B.ev)), B.uplo == 'U' ? :L : :U)
-transpose(B::Bidiagonal{<:Any, <:Base.ReshapedArray{<:Any,1,<:TransposeAbsVec}}) =
-    Bidiagonal(transpose(parent(B.dv)), transpose(parent(B.ev)), B.uplo == 'U' ? :L : :U)
+adjoint(B::Bidiagonal) = Bidiagonal(_vecadjoint(B.dv), _vecadjoint(B.ev), B.uplo == 'U' ? :L : :U)
+transpose(B::Bidiagonal) = Bidiagonal(_vectranspose(B.dv), _vectranspose(B.ev), B.uplo == 'U' ? :L : :U)
 permutedims(B::Bidiagonal) = Bidiagonal(B.dv, B.ev, B.uplo == 'U' ? 'L' : 'U')
 function permutedims(B::Bidiagonal, perm)
     Base.checkdims_perm(axes(B), axes(B), perm)

src/diagonal.jl

@@ -906,10 +906,8 @@ end
 end
 
 conj(D::Diagonal) = Diagonal(conj(D.diag))
-transpose(D::Diagonal) = Diagonal(vec(transpose(D.diag)))
-transpose(D::Diagonal{<:Any,<:Base.ReshapedArray{<:Any,1,<:TransposeAbsVec}}) = Diagonal(transpose(parent(D.diag)))
-adjoint(D::Diagonal) = Diagonal(vec(adjoint(D.diag)))
-adjoint(D::Diagonal{<:Any,<:Base.ReshapedArray{<:Any,1,<:AdjointAbsVec}}) = Diagonal(adjoint(parent(D.diag)))
+transpose(D::Diagonal) = Diagonal(_vectranspose(D.diag))
+adjoint(D::Diagonal) = Diagonal(_vecadjoint(D.diag))
 permutedims(D::Diagonal) = D
 permutedims(D::Diagonal, perm) = (Base.checkdims_perm(axes(D), axes(D), perm); D)