Fix mul! for HermOrSym sparse matrices (#689)

Author: dkarrasch

src/SparseArrays.jl

@@ -19,7 +19,7 @@ import Base: Matrix, Vector
 import LinearAlgebra: mul!, ldiv!, rdiv!, cholesky, adjoint!, diag, eigen, dot,
     issymmetric, istril, istriu, lu, tr, transpose!, tril!, triu!, isbanded, isdiag,
     cond, diagm, factorize, ishermitian, norm, opnorm, lmul!, rmul!, tril, triu,
-    matprod_dest, generic_matvecmul!, generic_matmatmul!, copytrito!
+    matprod_dest, generic_matvecmul!, generic_matmatmul!, generic_matmatmul_wrapper!, copytrito!
 
 import Base: adjoint, argmin, argmax, Array, broadcast, circshift!, complex, Complex,
     conj, conj!, convert, copy, copy!, copyto!, count, diff, findall, findmax, findmin,

src/linalg.jl

@@ -117,7 +117,7 @@ function _At_or_Ac_mul_B!(tfun::Function, C, A, B, α, β)
     C
 end
 
-Base.@constprop :aggressive function generic_matmatmul!(C::StridedMatrix, tA, tB, A::DenseMatrixUnion, B::SparseMatrixCSCUnion2, alpha::Number, beta::Number)
+Base.@constprop :aggressive function generic_matmatmul_wrapper!(C::StridedMatrix, tA, tB, A::DenseMatrixUnion, B::SparseMatrixCSCUnion2, alpha::Number, beta::Number, ::LinearAlgebra.BlasFlag.SyrkHerkGemm)
     transA = tA == 'N' ? identity : tA == 'T' ? transpose : adjoint
     if tB == 'N'
         _spmul!(C, transA(A), B, alpha, beta)
@@ -128,6 +128,9 @@ Base.@constprop :aggressive function generic_matmatmul!(C::StridedMatrix, tA, tB
     end
     return C
 end
+Base.@constprop :aggressive generic_matmatmul_wrapper!(C::StridedMatrix, tA, tB, A::DenseMatrixUnion, B::SparseMatrixCSCUnion2, alpha::Number, beta::Number, @nospecialize(val)) =
+    LinearAlgebra._generic_matmatmul!(C, wrap(A, tA), wrap(B, tB), alpha, beta)
+
 function _spmul!(C::StridedMatrix, X::DenseMatrixUnion, A::SparseMatrixCSCUnion2, α::Number, β::Number)
     mX, nX = size(X)
     nX == size(A, 1) ||

test/linalg.jl

@@ -236,6 +236,13 @@ end
     end
 end
 
+@testset "Dense times symmetric/Hermitian sparse matrix multiplication" begin
+    A = [1 3; 2 4]
+    As = sparse(A)
+    B = [1 1; 1 1]
+    @test mul!(copy(B), B, Hermitian(A), true, true) == mul!(copy(B), B, Hermitian(As), true, true)
+end
+
 @testset "Column view of sparse matrix " begin
     S = sparse(1:4, 1:4, 1:4)
     Sv = @view S[:,3:4]