only allow host arrays for blas mul

Author: lkdvos

ext/StridedGPUArraysExt.jl

@@ -20,15 +20,6 @@ function Base.Array(a::GPUStridedView)
     return Array(b)
 end
 
-function Strided.__mul!(
-        C::GPUStridedView{TC, 2},
-        A::GPUStridedView{TA, 2},
-        B::GPUStridedView{TB, 2},
-        α::Number, β::Number
-    ) where {TC, TA, TB}
-    return GPUArrays.generic_matmatmul!(C, A, B, α, β)
-end
-
 # ---------- GPU mapreduce support ----------
 
 @inline _gpu_init_acc(::Nothing, current_val) = current_val

src/linalg.jl

@@ -72,7 +72,8 @@ function LinearAlgebra.mul!(
     return C
 end
 
-function isblasmatrix(A::StridedView{T, 2}) where {T <: LinearAlgebra.BlasFloat}
+isblasmatrix(A::StridedView{T, 2}) where {T} = false
+function isblasmatrix(A::StridedView{T, 2, <:Array}) where {T <: LinearAlgebra.BlasFloat}
     if A.op == identity
         return stride(A, 1) == 1 || stride(A, 2) == 1
     elseif A.op == conj
@@ -81,6 +82,17 @@ function isblasmatrix(A::StridedView{T, 2}) where {T <: LinearAlgebra.BlasFloat}
         return false
     end
 end
+@static if isdefined(Core, :Memory)
+    function isblasmatrix(A::StridedView{T, 2, <:Memory}) where {T <: LinearAlgebra.BlasFloat}
+        if A.op == identity
+            return stride(A, 1) == 1 || stride(A, 2) == 1
+        elseif A.op == conj
+            return stride(A, 2) == 1
+        else # should never happen
+            return false
+        end
+    end
+end
 function getblasmatrix(A::StridedView{T, 2}) where {T <: LinearAlgebra.BlasFloat}
     if A.op == identity
         if stride(A, 1) == 1