From 975c69d6992e4a6879bbb19fab5f77d58b7f1bec Mon Sep 17 00:00:00 2001
From: Fredrik Ekre <ekrefredrik@gmail.com>
Date: Sun, 24 Jul 2022 00:52:52 +0200
Subject: [PATCH] Default rows for HYPREMatrix(::SparseMatrixCS(C|R)) and
 HYPREVector(::Vector)

This patch adds defaults for ilower and iupper in constructors when i)
using SparseMatrixCS(C|R) and Vector and ii) when no communicator is
passed. In this case we simply assume the users wants a single-processor
solve, and default to passing 1 and size(A, 1) as the default values.

In the future this could possibly use the HYPRE sequential compiler
flag to completely avoid MPI.
---
 src/HYPRE.jl     |  7 +++----
 test/runtests.jl | 25 +++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/src/HYPRE.jl b/src/HYPRE.jl
index 07b11a2..294ded2 100644
--- a/src/HYPRE.jl
+++ b/src/HYPRE.jl
@@ -207,7 +207,6 @@ function Internals.to_hypre_data(A::SparseMatrixCSR, ilower, iupper)
     return nrows, ncols, rows, cols, values
 end
 
-# TODO: Default to ilower = 1, iupper = size(B, 1)?
 function HYPREMatrix(comm::MPI.Comm, B::Union{SparseMatrixCSC,SparseMatrixCSR}, ilower, iupper)
     A = HYPREMatrix(comm, ilower, iupper)
     nrows, ncols, rows, cols, values = Internals.to_hypre_data(B, ilower, iupper)
@@ -216,7 +215,7 @@ function HYPREMatrix(comm::MPI.Comm, B::Union{SparseMatrixCSC,SparseMatrixCSR},
     return A
 end
 
-HYPREMatrix(B::Union{SparseMatrixCSC,SparseMatrixCSR}, ilower, iupper) =
+HYPREMatrix(B::Union{SparseMatrixCSC,SparseMatrixCSR}, ilower=1, iupper=size(B, 1)) =
     HYPREMatrix(MPI.COMM_WORLD, B, ilower, iupper)
 
 #########################
@@ -231,7 +230,6 @@ function Internals.to_hypre_data(x::Vector, ilower, iupper)
 end
 # TODO: Internals.to_hypre_data(x::SparseVector, ilower, iupper) (?)
 
-# TODO: Default to ilower = 1, iupper = length(x)?
 function HYPREVector(comm::MPI.Comm, x::Vector, ilower, iupper)
     b = HYPREVector(comm, ilower, iupper)
     nvalues, indices, values = Internals.to_hypre_data(x, ilower, iupper)
@@ -240,7 +238,8 @@ function HYPREVector(comm::MPI.Comm, x::Vector, ilower, iupper)
     return b
 end
 
-HYPREVector(x::Vector, ilower, iupper) = HYPREVector(MPI.COMM_WORLD, x, ilower, iupper)
+HYPREVector(x::Vector, ilower=1, iupper=length(x)) =
+    HYPREVector(MPI.COMM_WORLD, x, ilower, iupper)
 
 function Base.copy!(x::Vector, h::HYPREVector)
     ilower, iupper = Internals.get_proc_rows(h)
diff --git a/test/runtests.jl b/test/runtests.jl
index 8bf873c..2dfbc79 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -52,18 +52,36 @@ end
     CSC = sprand(5, 10, 0.3)
     CSR = sparsecsr(findnz(CSC)..., size(CSC)...)
     @test CSC == CSR
+
     H = HYPREMatrix(CSC, ilower, iupper)
     @test H.IJMatrix != HYPRE_IJMatrix(C_NULL)
     @test H.ParCSRMatrix != HYPRE_ParCSRMatrix(C_NULL)
     H = HYPREMatrix(MPI.COMM_WORLD, CSC, ilower, iupper)
     @test H.IJMatrix != HYPRE_IJMatrix(C_NULL)
     @test H.ParCSRMatrix != HYPRE_ParCSRMatrix(C_NULL)
+
     H = HYPREMatrix(CSR, ilower, iupper)
     @test H.IJMatrix != HYPRE_IJMatrix(C_NULL)
     @test H.ParCSRMatrix != HYPRE_ParCSRMatrix(C_NULL)
     H = HYPREMatrix(MPI.COMM_WORLD, CSR, ilower,  iupper)
     @test H.IJMatrix != HYPRE_IJMatrix(C_NULL)
     @test H.ParCSRMatrix != HYPRE_ParCSRMatrix(C_NULL)
+
+    # Default to owning all rows
+    CSC = sprand(10, 10, 0.3)
+    CSR = sparsecsr(findnz(CSC)..., size(CSC)...)
+    H = HYPREMatrix(CSC)
+    @test H.IJMatrix != HYPRE_IJMatrix(C_NULL)
+    @test H.ParCSRMatrix != HYPRE_ParCSRMatrix(C_NULL)
+    @test H.comm == MPI.COMM_WORLD
+    @test H.ilower == H.jlower == 1
+    @test H.iupper == H.jupper == 10
+    H = HYPREMatrix(CSR)
+    @test H.IJMatrix != HYPRE_IJMatrix(C_NULL)
+    @test H.ParCSRMatrix != HYPRE_ParCSRMatrix(C_NULL)
+    @test H.comm == MPI.COMM_WORLD
+    @test H.ilower == H.jlower == 1
+    @test H.iupper == H.jupper == 10
 end
 
 function tomain(x)
@@ -192,6 +210,13 @@ end
     @test h.IJVector != HYPRE_IJVector(C_NULL)
     @test h.ParVector != HYPRE_ParVector(C_NULL)
     @test_throws ArgumentError HYPREVector([1, 2], ilower, iupper)
+    # Default to owning all rows
+    h = HYPREVector(b)
+    @test h.IJVector != HYPRE_IJVector(C_NULL)
+    @test h.ParVector != HYPRE_ParVector(C_NULL)
+    @test h.comm == MPI.COMM_WORLD
+    @test h.ilower == 1
+    @test h.iupper == 10
 
     ilower, iupper = 1, 10
     b = rand(HYPRE_Complex, 10)