From 026783757650a617a3a55ccde314bee090011bb5 Mon Sep 17 00:00:00 2001
From: Fredrik Ekre <ekrefredrik@gmail.com>
Date: Sun, 24 Jul 2022 19:12:22 +0200
Subject: [PATCH] Add solve(!) methods for using SparseMatrixCS(C|R) directly.

---
 src/solvers.jl   | 18 ++++++++++++++++++
 test/runtests.jl | 16 ++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/src/solvers.jl b/src/solvers.jl
index e134981..05989a1 100644
--- a/src/solvers.jl
+++ b/src/solvers.jl
@@ -51,6 +51,24 @@ function solve!(solver::HYPRESolver, x::PVector, A::PSparseMatrix, b::PVector)
     return x
 end
 
+########################################
+# SparseMatrixCS(C|R) solver interface #
+########################################
+
+# TODO: This could use the HYPRE compile flag for sequential mode to avoid MPI overhead
+
+function solve(solver::HYPRESolver, A::Union{SparseMatrixCSC,SparseMatrixCSR}, b::Vector)
+    hypre_x = solve(solver, HYPREMatrix(A), HYPREVector(b))
+    x = copy!(copy(b), hypre_x)
+    return x
+end
+function solve!(solver::HYPRESolver, x::Vector, A::Union{SparseMatrixCSC,SparseMatrixCSR}, b::Vector)
+    hypre_x = HYPREVector(x)
+    solve!(solver, hypre_x, HYPREMatrix(A), HYPREVector(b))
+    copy!(x, hypre_x)
+    return x
+end
+
 
 #####################################
 ## Concrete solver implementations ##
diff --git a/test/runtests.jl b/test/runtests.jl
index 6a842b1..7d64bb7 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -454,3 +454,19 @@ end
     x_p = HYPRE.solve(pcg, A_p, b_p)
     @test tomain(x_p) ≈ A \ b atol=tol
 end
+
+@testset "solve with SparseMatrixCS(C|R)" begin
+    # Setup
+    A = sprand(100, 100, 0.05); A = A'A + 5I
+    b = rand(100)
+    x = zeros(100)
+    # Solve
+    tol = 1e-9
+    pcg = HYPRE.PCG(; Tol = tol)
+    ## solve!
+    HYPRE.solve!(pcg, x, A, b)
+    @test x ≈ A \ b atol=tol
+    ## solve
+    x = HYPRE.solve(pcg, A, b)
+    @test x ≈ A \ b atol=tol
+end