efficiency

Author: wsmoses

src/internal_rules.jl

@@ -924,8 +924,10 @@ end
 
 function cofactor(A)
     cofA     = zeros(eltype(A), size(A))
-    minorAij = zeros(eltype(A), size(A, 1) - 1, size(A, 2) - 1)
+    minorAij = similar(A, size(A, 1) - 1, size(A, 2) - 1)
     for i in 1:size(A, 1), j in 1:size(A, 2)
+        fill!(minorAij, zero(eltype(A)))
+        
         # build minor matrix
         for k in 1:size(A, 1), l in 1:size(A, 2)
             if !(k == i || l == j)
@@ -935,13 +937,12 @@ function cofactor(A)
             end
         end
         @inbounds cofA[i, j] = (-1)^(i - 1 + j - 1) * det(minorAij)
-        minorAij .= zero(eltype(A))
     end
     return cofA
 end
-# partial derivative of the determinant is the matrix of
-# cofactors
-EnzymeRules.@easy_rule(LinearAlgebra.det(A), (cofactor(A),))
+
+# partial derivative of the determinant is the matrix of cofactors
+EnzymeRules.@easy_rule(LinearAlgebra.det(A::AbstractMatrix), (cofactor(A),))
 
 function EnzymeRules.forward(
     config::EnzymeRules.FwdConfig,