If INCLUDE_SPARSE is false, then default to KrylovJL_GMRES() for sparse matrices

Author: DilumAluthge

src/default.jl

@@ -34,11 +34,17 @@ function defaultalg(A::SymTridiagonal, b, ::OperatorAssumptions{true})
     GenericFactorization(; fact_alg = ldlt!)
 end
 
-function defaultalg(A::SparseMatrixCSC, b, ::OperatorAssumptions{true})
-    if length(b) <= 10_000
-        KLUFactorization()
-    else
-        UMFPACKFactorization()
+@static if INCLUDE_SPARSE
+    function defaultalg(A::SparseMatrixCSC, b, ::OperatorAssumptions{true})
+        if length(b) <= 10_000
+            KLUFactorization()
+        else
+            UMFPACKFactorization()
+        end
+    end
+else
+    function defaultalg(A::SparseMatrixCSC, b, ::OperatorAssumptions{true})
+        KrylovJL_GMRES()
     end
 end
 
@@ -51,11 +57,7 @@ function defaultalg(A::GPUArraysCore.AbstractGPUArray, b, ::OperatorAssumptions{
 end
 
 function defaultalg(A, b::GPUArraysCore.AbstractGPUArray, ::OperatorAssumptions{true})
-    if VERSION >= v"1.8-"
-        LUFactorization()
-    else
-        QRFactorization()
-    end
+    KrylovJL_GMRES()
 end
 
 function defaultalg(A::SciMLBase.AbstractDiffEqOperator, b,