Fix type promote in case b is complex

src/common.jl

@@ -115,8 +115,8 @@ function SciMLBase.init(prob::LinearProblem, alg::SciMLLinearSolveAlgorithm,
     args...;
     alias_A = default_alias_A(alg, prob.A, prob.b),
     alias_b = default_alias_b(alg, prob.A, prob.b),
-    abstol = default_tol(eltype(prob.b)),
-    reltol = default_tol(eltype(prob.b)),
+    abstol = default_tol(real(eltype(prob.b))),
+    reltol = default_tol(real(eltype(prob.b))),
     maxiters::Int = length(prob.b),
     verbose::Bool = false,
     Pl = IdentityOperator(size(prob.A)[1]),
@@ -151,8 +151,8 @@ function SciMLBase.init(prob::LinearProblem, alg::SciMLLinearSolveAlgorithm,
     end
 
     # Guard against type mismatch for user-specified reltol/abstol
-    reltol = eltype(prob.b)(reltol)
-    abstol = eltype(prob.b)(abstol)
+    reltol = real(eltype(prob.b))(reltol)
+    abstol = real(eltype(prob.b))(abstol)
 
     cacheval = init_cacheval(alg, A, b, u0, Pl, Pr, maxiters, abstol, reltol, verbose,
         assumptions)

src/factorization.jl

@@ -16,7 +16,7 @@ function _ldiv!(x::Vector, A::Factorization, b::Vector)
     ldiv!(A, x)
 end
 
-#RF Bad fallback: will fail if `A` is just a stand-in
+# RF Bad fallback: will fail if `A` is just a stand-in
 # This should instead just create the factorization type.
 function init_cacheval(alg::AbstractFactorization, A, b, u, Pl, Pr, maxiters::Int, abstol,
     reltol, verbose::Bool, assumptions::OperatorAssumptions)

test/basictests.jl

@@ -9,37 +9,52 @@ const Dual64 = ForwardDiff.Dual{Nothing, Float64, 1}
 n = 8
 A = Matrix(I, n, n)
 b = ones(n)
+# Real-valued systems
 A1 = A / 1;
 b1 = rand(n);
 x1 = zero(b);
+# A2 is similar to A1; created to test cache reuse
 A2 = A / 2;
 b2 = rand(n);
 x2 = zero(b);
+# Complex systems + mismatched types with eltype(tol)
+A3 = A1 .|> ComplexF32
+b3 = b1 .|> ComplexF32
+x3 = x1 .|> ComplexF32
+# A4 is similar to A3; created to test cache reuse
+A4 = A2 .|> ComplexF32
+b4 = b2 .|> ComplexF32
+x4 = x2 .|> ComplexF32
 
 prob1 = LinearProblem(A1, b1; u0 = x1)
 prob2 = LinearProblem(A2, b2; u0 = x2)
+prob3 = LinearProblem(A3, b3; u0 = x3)
+prob4 = LinearProblem(A4, b4; u0 = x4)
 
 cache_kwargs = (; verbose = true, abstol = 1e-8, reltol = 1e-8, maxiter = 30)
 
 function test_interface(alg, prob1, prob2)
-    A1 = prob1.A
-    b1 = prob1.b
-    x1 = prob1.u0
-    A2 = prob2.A
-    b2 = prob2.b
-    x2 = prob2.u0
+    A1, b1 = prob1.A, prob1.b
+    A2, b2 = prob2.A, prob2.b
 
     sol = solve(prob1, alg; cache_kwargs...)
     @test A1 * sol.u ≈ b1
 
+    sol = solve(prob2, alg; cache_kwargs...)
+    @test A2 * sol.u ≈ b2
+
+    # Test cache resue: base mechanism
     cache = SciMLBase.init(prob1, alg; cache_kwargs...) # initialize cache
     sol = solve!(cache)
     @test A1 * sol.u ≈ b1
+
+    # Test cache resue: only A changes
     cache.A = deepcopy(A2)
     sol = solve!(cache; cache_kwargs...)
     @test A2 * sol.u ≈ b1
 
-    cache.A = A2
+    # Test cache resue: both A and b change
+    cache.A = deepcopy(A2)
     cache.b = b2
     sol = solve!(cache; cache_kwargs...)
     @test A2 * sol.u ≈ b2
@@ -50,6 +65,7 @@ end
 @testset "LinearSolve" begin
     @testset "Default Linear Solver" begin
         test_interface(nothing, prob1, prob2)
+        test_interface(nothing, prob3, prob4)
 
         A1 = prob1.A * prob1.A'
         b1 = prob1.b
@@ -202,25 +218,24 @@ end
         end
     end
 
-    test_algs = if VERSION >= v"1.9" && LinearSolve.usemkl
-        (LUFactorization(),
-            QRFactorization(),
-            SVDFactorization(),
-            RFLUFactorization(),
-            MKLLUFactorization(),
-            LinearSolve.defaultalg(prob1.A, prob1.b))
-    else
-        (LUFactorization(),
-            QRFactorization(),
-            SVDFactorization(),
-            RFLUFactorization(),
-            LinearSolve.defaultalg(prob1.A, prob1.b))
+
+    test_algs = [
+        LUFactorization(),
+        QRFactorization(),
+        SVDFactorization(),
+        RFLUFactorization(),
+        LinearSolve.defaultalg(prob1.A, prob1.b),
+    ]
+
+    if VERSION >= v"1.9" && LinearSolve.usemkl
+        push!(test_algs, MKLLUFactorization())
     end
 
     @testset "Concrete Factorizations" begin
         for alg in test_algs
             @testset "$alg" begin
                 test_interface(alg, prob1, prob2)
+                VERSION >= v"1.9" && (alg isa MKLLUFactorization || test_interface(alg, prob3, prob4))
             end
         end
         if LinearSolve.appleaccelerate_isavailable()
@@ -232,15 +247,16 @@ end
         for fact_alg in (lu, lu!,
             qr, qr!,
             cholesky,
-            #cholesky!,
-            #ldlt, ldlt!,
+            # cholesky!,
+            # ldlt, ldlt!,
             bunchkaufman, bunchkaufman!,
             lq, lq!,
             svd, svd!,
             LinearAlgebra.factorize)
             @testset "fact_alg = $fact_alg" begin
                 alg = GenericFactorization(fact_alg = fact_alg)
                 test_interface(alg, prob1, prob2)
+                test_interface(alg, prob3, prob4)
             end
         end
     end
@@ -251,13 +267,17 @@ end
 
     @testset "KrylovJL" begin
         kwargs = (; gmres_restart = 5)
-        for alg in (("Default", KrylovJL(kwargs...)),
+        algorithms = (
+            ("Default", KrylovJL(kwargs...)),
             ("CG", KrylovJL_CG(kwargs...)),
             ("GMRES", KrylovJL_GMRES(kwargs...)),
-            #           ("BICGSTAB",KrylovJL_BICGSTAB(kwargs...)),
-            ("MINRES", KrylovJL_MINRES(kwargs...)))
-            @testset "$(alg[1])" begin
-                test_interface(alg[2], prob1, prob2)
+            # ("BICGSTAB",KrylovJL_BICGSTAB(kwargs...)),
+            ("MINRES", KrylovJL_MINRES(kwargs...))
+        )
+        for (name, algorithm) in algorithms
+            @testset "$name" begin
+                test_interface(algorithm, prob1, prob2)
+                test_interface(algorithm, prob3, prob4)
             end
         end
     end
@@ -274,6 +294,7 @@ end
             )
                 @testset "$(alg[1])" begin
                     test_interface(alg[2], prob1, prob2)
+                    test_interface(alg[2], prob3, prob4)
                 end
             end
         end
@@ -287,6 +308,7 @@ end
                 ("GMRES", KrylovKitJL_GMRES(kwargs...)))
                 @testset "$(alg[1])" begin
                     test_interface(alg[2], prob1, prob2)
+                    test_interface(alg[2], prob3, prob4)
                 end
                 @test alg[2] isa KrylovKitJL
             end