promote types

Author: Michael Abbott

src/batched/batchedmul.jl

@@ -11,7 +11,8 @@ Batched matrix multiplication. Result has `C[:,:,k] == A[:,:,k] * B[:,:,k]` for
 """
 function batched_mul(A::AbstractArray{T1, 3}, B::AbstractArray{T2, 3}) where {T1, T2}
     axes(A, 3) == axes(B, 3) || throw(DimensionMismatch("batch size mismatch"))
-    C = similar(A, (axes(A, 1), axes(B, 2), axes(A, 3)))
+    T = promote_type(T1, T2)
+    C = similar(A, T, (axes(A, 1), axes(B, 2), axes(A, 3)))
     batched_mul!(C, A, B)
 end
 

test/batchedmul.jl

@@ -52,6 +52,7 @@ end
     iB = TB.(rand(1:99, 5,7,3))
     iC = zeros(Int, 7,6,3)
     @test batched_mul(iA, iB) == bmm_adjtest(iA, iB)
+    @test batched_mul(cA, iB) ≈ bmm_adjtest(cA, iB)
 
     @test_throws DimensionMismatch batched_mul(rand(2,2,2), rand(TB, 2,2,10))
     @test_throws DimensionMismatch batched_mul(rand(2,2,2), rand(TB, 10,2,2))