mul! for SubArrays of LayoutMatrix (#145)

* merge

* add tests

Author: dlfivefifty

Project.toml

@@ -1,7 +1,7 @@
 name = "ArrayLayouts"
 uuid = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"
 authors = ["Sheehan Olver <[email protected]>"]
-version = "1.0.8"
+version = "1.0.9"
 
 [deps]
 FillArrays = "1a297f60-69ca-5386-bcde-b61e274b549b"

src/mul.jl

@@ -310,6 +310,12 @@ end
 *(x::TransposeAbsVec{<:Any,<:Zeros{<:Any,1}}, D::Diagonal, y::LayoutVector) = FillArrays._triple_zeromul(x, D, y)
 
 
+# mul! for subarray of layout matrix
+LinearAlgebra.mul!(C::SubArray{<:Any,2,<:LayoutMatrix}, A::SubArray{<:Any,2,<:LayoutMatrix}, B::SubArray{<:Any,2,<:LayoutMatrix}, α::Number, β::Number) =
+    ArrayLayouts.mul!(C, A, B, α, β)
+LinearAlgebra.mul!(C::AbstractMatrix, A::SubArray{<:Any,2,<:LayoutMatrix}, B::SubArray{<:Any,2,<:LayoutMatrix}, α::Number, β::Number) =
+    ArrayLayouts.mul!(C, A, B, α, β)    
+
 
 ###
 # Dot

test/test_layoutarray.jl

@@ -188,6 +188,10 @@ MemoryLayout(::Type{MyVector}) = DenseColumnMajor()
 
             @test mul!(copy(B), A, Diagonal(Bin), 2, 3) ≈ 2A*Diagonal(Bin) + 3B
             @test mul!(copy(B), Diagonal(Bin), A, 2, 3) ≈ 2Diagonal(Bin)*A + 3B
+
+            @test mul!(view(copy(B), 1:3, 1:3), view(A, 1:3, 1:3), view(B, 1:3, 1:3)) ≈ A[1:3,1:3]*B[1:3,1:3]
+            @test mul!(Matrix{Float64}(undef, 3, 3), view(A, 1:3, 1:3), view(B, 1:3, 1:3)) ≈ A[1:3,1:3]*B[1:3,1:3]
+            @test mul!(MyMatrix(Matrix{Float64}(undef, 3, 3)), view(A, 1:3, 1:3), view(B, 1:3, 1:3)) ≈ A[1:3,1:3]*B[1:3,1:3]
         end
 
         @testset "generic_blasmul!" begin