New SPSPMM implementation

base/modules/Makefile

@@ -60,7 +60,11 @@ SERIAL_MODS=serial/psb_s_serial_mod.o serial/psb_d_serial_mod.o \
 	auxil/psb_d_hsort_x_mod.o \
 	auxil/psb_c_hsort_x_mod.o \
 	auxil/psb_z_hsort_x_mod.o \
-	auxil/psb_d_rb_idx_tree_mod.o auxil/psb_rb_idx_tree_mod.o \
+	auxil/psb_s_rb_idx_tree_mod.o \
+	auxil/psb_d_rb_idx_tree_mod.o \
+	auxil/psb_c_rb_idx_tree_mod.o \
+	auxil/psb_z_rb_idx_tree_mod.o \
+	auxil/psb_rb_idx_tree_mod.o \
 	serial/psb_base_mat_mod.o   serial/psb_mat_mod.o\
 	serial/psb_s_base_mat_mod.o serial/psb_s_csr_mat_mod.o serial/psb_s_csc_mat_mod.o serial/psb_s_mat_mod.o \
 	serial/psb_d_base_mat_mod.o serial/psb_d_csr_mat_mod.o serial/psb_d_csc_mat_mod.o serial/psb_d_mat_mod.o \
@@ -277,8 +281,11 @@ serial/psb_z_vect_mod.o: serial/psb_z_base_vect_mod.o serial/psb_i_vect_mod.o
 serial/psb_s_serial_mod.o serial/psb_d_serial_mod.o serial/psb_c_serial_mod.o serial/psb_z_serial_mod.o: serial/psb_mat_mod.o auxil/psb_string_mod.o auxil/psb_sort_mod.o auxil/psi_serial_mod.o
 serial/psb_vect_mod.o: serial/psb_i_vect_mod.o serial/psb_l_vect_mod.o serial/psb_d_vect_mod.o serial/psb_s_vect_mod.o serial/psb_c_vect_mod.o serial/psb_z_vect_mod.o
 
+auxil/psb_s_rb_idx_tree_mod.o: serial/psb_s_csr_mat_mod.o psb_realloc_mod.o
 auxil/psb_d_rb_idx_tree_mod.o: serial/psb_d_csr_mat_mod.o psb_realloc_mod.o
-auxil/psb_rb_idx_tree_mod.o: auxil/psb_d_rb_idx_tree_mod.o
+auxil/psb_c_rb_idx_tree_mod.o: serial/psb_c_csr_mat_mod.o psb_realloc_mod.o
+auxil/psb_z_rb_idx_tree_mod.o: serial/psb_z_csr_mat_mod.o psb_realloc_mod.o
+auxil/psb_rb_idx_tree_mod.o: auxil/psb_s_rb_idx_tree_mod.o auxil/psb_d_rb_idx_tree_mod.o auxil/psb_c_rb_idx_tree_mod.o auxil/psb_z_rb_idx_tree_mod.o
 
 error.o psb_realloc_mod.o: psb_error_mod.o 
 psb_error_impl.o: psb_penv_mod.o

base/modules/auxil/psb_c_rb_idx_tree_mod.f90

@@ -0,0 +1,128 @@
+!
+!                Parallel Sparse BLAS  version 3.5
+!      (C) Copyright 2006-2018
+!        Salvatore Filippone
+!        Alfredo Buttari
+!
+!    Redistribution and use in source and binary forms, with or without
+!    modification, are permitted provided that the following conditions
+!    are met:
+!      1. Redistributions of source code must retain the above copyright
+!         notice, this list of conditions and the following disclaimer.
+!      2. Redistributions in binary form must reproduce the above copyright
+!         notice, this list of conditions, and the following disclaimer in the
+!         documentation and/or other materials provided with the distribution.
+!      3. The name of the PSBLAS group or the names of its contributors may
+!         not be used to endorse or promote products derived from this
+!         software without specific written permission.
+!
+!    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+!    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+!    TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+!    PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE PSBLAS GROUP OR ITS CONTRIBUTORS
+!    BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+!    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+!    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+!    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+!    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+!    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+!    POSSIBILITY OF SUCH DAMAGE.
+!
+!
+!
+! package: psb_c_rb_idx_tree_mod
+! 
+! Red black tree implementation ordered by index
+!
+! Each node contains and index and a double precision value
+!
+! The tree should always be well balanced
+!
+! inserting a node with an existing index will 
+! add up the new value to the old one
+! Contributed by Dimitri Walther
+! 
+module psb_c_rb_idx_tree_mod
+  use psb_const_mod
+  implicit none
+
+  type :: psb_c_rb_idx_node
+    integer(psb_ipk_) :: idx
+    complex(psb_spk_) :: val
+    type(psb_c_rb_idx_node), pointer :: left, right, parent
+    logical :: is_red
+  end type psb_c_rb_idx_node
+
+  type :: psb_c_rb_idx_tree
+    type(psb_c_rb_idx_node), pointer :: root
+    integer(psb_ipk_) :: nnz
+
+  contains
+
+    procedure :: insert => psb_c_rb_idx_tree_insert
+  end type psb_c_rb_idx_tree
+
+  interface psb_rb_idx_tree_insert
+    subroutine psb_c_rb_idx_tree_insert(this, idx, val)
+      import :: psb_ipk_, psb_spk_, psb_c_rb_idx_tree
+      implicit none
+      class(psb_c_rb_idx_tree), intent(inout) :: this
+      integer(psb_ipk_), intent(in) :: idx
+      complex(psb_spk_), intent(in) :: val
+    end subroutine psb_c_rb_idx_tree_insert
+  end interface psb_rb_idx_tree_insert
+
+  interface psb_rb_idx_tree_scalar_sparse_row_mul
+    subroutine psb_c_rb_idx_tree_scalar_sparse_row_mul(tree, scalar, mat, row_num)
+      use psb_c_csr_mat_mod, only : psb_c_csr_sparse_mat
+      import :: psb_ipk_, psb_spk_, psb_c_rb_idx_tree
+      implicit none
+      type(psb_c_rb_idx_tree), intent(inout) :: tree
+      complex(psb_spk_), intent(in) :: scalar
+      type(psb_c_csr_sparse_mat), intent(in) :: mat
+      integer(psb_ipk_), intent(in) :: row_num
+    end subroutine psb_c_rb_idx_tree_scalar_sparse_row_mul
+  end interface psb_rb_idx_tree_scalar_sparse_row_mul
+
+  interface psb_rb_idx_tree_merge
+    subroutine psb_c_rb_idx_tree_merge(trees, mat)
+      use psb_c_csr_mat_mod, only : psb_c_csr_sparse_mat
+      import :: psb_c_rb_idx_tree
+      type(psb_c_rb_idx_tree), allocatable, intent(inout) :: trees(:)
+      type(psb_c_csr_sparse_mat), intent(inout) :: mat
+    end subroutine psb_c_rb_idx_tree_merge
+  end interface psb_rb_idx_tree_merge
+
+  interface psb_rb_idx_tree_fix_insertion
+    subroutine psb_c_rb_idx_tree_fix_insertion(this, node)
+      import :: psb_c_rb_idx_tree, psb_c_rb_idx_node
+      implicit none
+      class(psb_c_rb_idx_tree), intent(inout) :: this
+      type(psb_c_rb_idx_node), pointer, intent(inout) :: node
+    end subroutine psb_c_rb_idx_tree_fix_insertion
+  end interface psb_rb_idx_tree_fix_insertion
+
+  interface psb_rb_idx_tree_swap_colors
+    subroutine psb_c_rb_idx_tree_swap_colors(n1, n2)
+      import :: psb_c_rb_idx_node
+      implicit none
+      type(psb_c_rb_idx_node), pointer, intent(inout) :: n1, n2
+    end subroutine psb_c_rb_idx_tree_swap_colors
+  end interface psb_rb_idx_tree_swap_colors
+
+  interface psb_rb_idx_tree_rotate_right
+    subroutine psb_c_rb_idx_tree_rotate_right(node)
+      import :: psb_c_rb_idx_node
+      implicit none
+      type(psb_c_rb_idx_node), pointer, intent(inout) :: node
+    end subroutine psb_c_rb_idx_tree_rotate_right
+  end interface psb_rb_idx_tree_rotate_right
+
+  interface psb_rb_idx_tree_rotate_left
+    subroutine psb_c_rb_idx_tree_rotate_left(node)
+      import :: psb_c_rb_idx_node
+      implicit none
+      type(psb_c_rb_idx_node), pointer, intent(inout) :: node
+    end subroutine psb_c_rb_idx_tree_rotate_left
+  end interface psb_rb_idx_tree_rotate_left
+end module psb_c_rb_idx_tree_mod

base/modules/auxil/psb_rb_idx_tree_mod.f90

@@ -45,5 +45,8 @@
 module psb_rb_idx_tree_mod
   use psb_const_mod
   
+  use psb_s_rb_idx_tree_mod
   use psb_d_rb_idx_tree_mod
+  use psb_c_rb_idx_tree_mod
+  use psb_z_rb_idx_tree_mod
 end module psb_rb_idx_tree_mod

base/modules/auxil/psb_s_rb_idx_tree_mod.f90

@@ -0,0 +1,128 @@
+!
+!                Parallel Sparse BLAS  version 3.5
+!      (C) Copyright 2006-2018
+!        Salvatore Filippone
+!        Alfredo Buttari
+!
+!    Redistribution and use in source and binary forms, with or without
+!    modification, are permitted provided that the following conditions
+!    are met:
+!      1. Redistributions of source code must retain the above copyright
+!         notice, this list of conditions and the following disclaimer.
+!      2. Redistributions in binary form must reproduce the above copyright
+!         notice, this list of conditions, and the following disclaimer in the
+!         documentation and/or other materials provided with the distribution.
+!      3. The name of the PSBLAS group or the names of its contributors may
+!         not be used to endorse or promote products derived from this
+!         software without specific written permission.
+!
+!    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+!    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+!    TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+!    PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE PSBLAS GROUP OR ITS CONTRIBUTORS
+!    BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+!    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+!    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+!    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+!    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+!    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+!    POSSIBILITY OF SUCH DAMAGE.
+!
+!
+!
+! package: psb_s_rb_idx_tree_mod
+! 
+! Red black tree implementation ordered by index
+!
+! Each node contains and index and a double precision value
+!
+! The tree should always be well balanced
+!
+! inserting a node with an existing index will 
+! add up the new value to the old one
+! Contributed by Dimitri Walther
+! 
+module psb_s_rb_idx_tree_mod
+  use psb_const_mod
+  implicit none
+
+  type :: psb_s_rb_idx_node
+    integer(psb_ipk_) :: idx
+    real(psb_spk_) :: val
+    type(psb_s_rb_idx_node), pointer :: left, right, parent
+    logical :: is_red
+  end type psb_s_rb_idx_node
+
+  type :: psb_s_rb_idx_tree
+    type(psb_s_rb_idx_node), pointer :: root
+    integer(psb_ipk_) :: nnz
+
+  contains
+
+    procedure :: insert => psb_s_rb_idx_tree_insert
+  end type psb_s_rb_idx_tree
+
+  interface psb_rb_idx_tree_insert
+    subroutine psb_s_rb_idx_tree_insert(this, idx, val)
+      import :: psb_ipk_, psb_spk_, psb_s_rb_idx_tree
+      implicit none
+      class(psb_s_rb_idx_tree), intent(inout) :: this
+      integer(psb_ipk_), intent(in) :: idx
+      real(psb_spk_), intent(in) :: val
+    end subroutine psb_s_rb_idx_tree_insert
+  end interface psb_rb_idx_tree_insert
+
+  interface psb_rb_idx_tree_scalar_sparse_row_mul
+    subroutine psb_s_rb_idx_tree_scalar_sparse_row_mul(tree, scalar, mat, row_num)
+      use psb_s_csr_mat_mod, only : psb_s_csr_sparse_mat
+      import :: psb_ipk_, psb_spk_, psb_s_rb_idx_tree
+      implicit none
+      type(psb_s_rb_idx_tree), intent(inout) :: tree
+      real(psb_spk_), intent(in) :: scalar
+      type(psb_s_csr_sparse_mat), intent(in) :: mat
+      integer(psb_ipk_), intent(in) :: row_num
+    end subroutine psb_s_rb_idx_tree_scalar_sparse_row_mul
+  end interface psb_rb_idx_tree_scalar_sparse_row_mul
+
+  interface psb_rb_idx_tree_merge
+    subroutine psb_s_rb_idx_tree_merge(trees, mat)
+      use psb_s_csr_mat_mod, only : psb_s_csr_sparse_mat
+      import :: psb_s_rb_idx_tree
+      type(psb_s_rb_idx_tree), allocatable, intent(inout) :: trees(:)
+      type(psb_s_csr_sparse_mat), intent(inout) :: mat
+    end subroutine psb_s_rb_idx_tree_merge
+  end interface psb_rb_idx_tree_merge
+
+  interface psb_rb_idx_tree_fix_insertion
+    subroutine psb_s_rb_idx_tree_fix_insertion(this, node)
+      import :: psb_s_rb_idx_tree, psb_s_rb_idx_node
+      implicit none
+      class(psb_s_rb_idx_tree), intent(inout) :: this
+      type(psb_s_rb_idx_node), pointer, intent(inout) :: node
+    end subroutine psb_s_rb_idx_tree_fix_insertion
+  end interface psb_rb_idx_tree_fix_insertion
+
+  interface psb_rb_idx_tree_swap_colors
+    subroutine psb_s_rb_idx_tree_swap_colors(n1, n2)
+      import :: psb_s_rb_idx_node
+      implicit none
+      type(psb_s_rb_idx_node), pointer, intent(inout) :: n1, n2
+    end subroutine psb_s_rb_idx_tree_swap_colors
+  end interface psb_rb_idx_tree_swap_colors
+
+  interface psb_rb_idx_tree_rotate_right
+    subroutine psb_s_rb_idx_tree_rotate_right(node)
+      import :: psb_s_rb_idx_node
+      implicit none
+      type(psb_s_rb_idx_node), pointer, intent(inout) :: node
+    end subroutine psb_s_rb_idx_tree_rotate_right
+  end interface psb_rb_idx_tree_rotate_right
+
+  interface psb_rb_idx_tree_rotate_left
+    subroutine psb_s_rb_idx_tree_rotate_left(node)
+      import :: psb_s_rb_idx_node
+      implicit none
+      type(psb_s_rb_idx_node), pointer, intent(inout) :: node
+    end subroutine psb_s_rb_idx_tree_rotate_left
+  end interface psb_rb_idx_tree_rotate_left
+end module psb_s_rb_idx_tree_mod

base/modules/auxil/psb_z_rb_idx_tree_mod.f90

@@ -0,0 +1,128 @@
+!
+!                Parallel Sparse BLAS  version 3.5
+!      (C) Copyright 2006-2018
+!        Salvatore Filippone
+!        Alfredo Buttari
+!
+!    Redistribution and use in source and binary forms, with or without
+!    modification, are permitted provided that the following conditions
+!    are met:
+!      1. Redistributions of source code must retain the above copyright
+!         notice, this list of conditions and the following disclaimer.
+!      2. Redistributions in binary form must reproduce the above copyright
+!         notice, this list of conditions, and the following disclaimer in the
+!         documentation and/or other materials provided with the distribution.
+!      3. The name of the PSBLAS group or the names of its contributors may
+!         not be used to endorse or promote products derived from this
+!         software without specific written permission.
+!
+!    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+!    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+!    TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+!    PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE PSBLAS GROUP OR ITS CONTRIBUTORS
+!    BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+!    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+!    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+!    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+!    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+!    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+!    POSSIBILITY OF SUCH DAMAGE.
+!
+!
+!
+! package: psb_z_rb_idx_tree_mod
+! 
+! Red black tree implementation ordered by index
+!
+! Each node contains and index and a double precision value
+!
+! The tree should always be well balanced
+!
+! inserting a node with an existing index will 
+! add up the new value to the old one
+! Contributed by Dimitri Walther
+! 
+module psb_z_rb_idx_tree_mod
+  use psb_const_mod
+  implicit none
+
+  type :: psb_z_rb_idx_node
+    integer(psb_ipk_) :: idx
+    complex(psb_dpk_) :: val
+    type(psb_z_rb_idx_node), pointer :: left, right, parent
+    logical :: is_red
+  end type psb_z_rb_idx_node
+
+  type :: psb_z_rb_idx_tree
+    type(psb_z_rb_idx_node), pointer :: root
+    integer(psb_ipk_) :: nnz
+
+  contains
+
+    procedure :: insert => psb_z_rb_idx_tree_insert
+  end type psb_z_rb_idx_tree
+
+  interface psb_rb_idx_tree_insert
+    subroutine psb_z_rb_idx_tree_insert(this, idx, val)
+      import :: psb_ipk_, psb_dpk_, psb_z_rb_idx_tree
+      implicit none
+      class(psb_z_rb_idx_tree), intent(inout) :: this
+      integer(psb_ipk_), intent(in) :: idx
+      complex(psb_dpk_), intent(in) :: val
+    end subroutine psb_z_rb_idx_tree_insert
+  end interface psb_rb_idx_tree_insert
+
+  interface psb_rb_idx_tree_scalar_sparse_row_mul
+    subroutine psb_z_rb_idx_tree_scalar_sparse_row_mul(tree, scalar, mat, row_num)
+      use psb_z_csr_mat_mod, only : psb_z_csr_sparse_mat
+      import :: psb_ipk_, psb_dpk_, psb_z_rb_idx_tree
+      implicit none
+      type(psb_z_rb_idx_tree), intent(inout) :: tree
+      complex(psb_dpk_), intent(in) :: scalar
+      type(psb_z_csr_sparse_mat), intent(in) :: mat
+      integer(psb_ipk_), intent(in) :: row_num
+    end subroutine psb_z_rb_idx_tree_scalar_sparse_row_mul
+  end interface psb_rb_idx_tree_scalar_sparse_row_mul
+
+  interface psb_rb_idx_tree_merge
+    subroutine psb_z_rb_idx_tree_merge(trees, mat)
+      use psb_z_csr_mat_mod, only : psb_z_csr_sparse_mat
+      import :: psb_z_rb_idx_tree
+      type(psb_z_rb_idx_tree), allocatable, intent(inout) :: trees(:)
+      type(psb_z_csr_sparse_mat), intent(inout) :: mat
+    end subroutine psb_z_rb_idx_tree_merge
+  end interface psb_rb_idx_tree_merge
+
+  interface psb_rb_idx_tree_fix_insertion
+    subroutine psb_z_rb_idx_tree_fix_insertion(this, node)
+      import :: psb_z_rb_idx_tree, psb_z_rb_idx_node
+      implicit none
+      class(psb_z_rb_idx_tree), intent(inout) :: this
+      type(psb_z_rb_idx_node), pointer, intent(inout) :: node
+    end subroutine psb_z_rb_idx_tree_fix_insertion
+  end interface psb_rb_idx_tree_fix_insertion
+
+  interface psb_rb_idx_tree_swap_colors
+    subroutine psb_z_rb_idx_tree_swap_colors(n1, n2)
+      import :: psb_z_rb_idx_node
+      implicit none
+      type(psb_z_rb_idx_node), pointer, intent(inout) :: n1, n2
+    end subroutine psb_z_rb_idx_tree_swap_colors
+  end interface psb_rb_idx_tree_swap_colors
+
+  interface psb_rb_idx_tree_rotate_right
+    subroutine psb_z_rb_idx_tree_rotate_right(node)
+      import :: psb_z_rb_idx_node
+      implicit none
+      type(psb_z_rb_idx_node), pointer, intent(inout) :: node
+    end subroutine psb_z_rb_idx_tree_rotate_right
+  end interface psb_rb_idx_tree_rotate_right
+
+  interface psb_rb_idx_tree_rotate_left
+    subroutine psb_z_rb_idx_tree_rotate_left(node)
+      import :: psb_z_rb_idx_node
+      implicit none
+      type(psb_z_rb_idx_node), pointer, intent(inout) :: node
+    end subroutine psb_z_rb_idx_tree_rotate_left
+  end interface psb_rb_idx_tree_rotate_left
+end module psb_z_rb_idx_tree_mod

base/modules/serial/psb_d_csr_mat_mod.f90

@@ -45,6 +45,7 @@
 module psb_d_csr_mat_mod
 
   use psb_d_base_mat_mod
+
   !> \namespace  psb_base_mod  \class  psb_d_csr_sparse_mat
   !! \extends psb_d_base_mat_mod::psb_d_base_sparse_mat
   !!

base/modules/serial/psb_d_mat_mod.F90

@@ -79,10 +79,7 @@
 module psb_d_mat_mod
 
   use psb_d_base_mat_mod
-  use psb_d_csr_mat_mod,  only : psb_d_csr_sparse_mat, psb_ld_csr_sparse_mat, &
+  use psb_d_csr_mat_mod,  only : psb_d_csr_sparse_mat, psb_ld_csr_sparse_mat
-                                spspmm_impl, spspmm_serial, spspmm_omp_gustavson, &
-                                spspmm_omp_gustavson_1d, spspmm_serial_rb_tree, &
-                                spspmm_omp_rb_tree, spspmm_omp_two_pass
   use psb_d_csc_mat_mod,  only : psb_d_csc_sparse_mat, psb_ld_csc_sparse_mat
 
   type :: psb_dspmat_type

base/serial/impl/Makefile

@@ -7,16 +7,20 @@ BOBJS=psb_base_mat_impl.o \
   psb_s_base_mat_impl.o psb_d_base_mat_impl.o psb_c_base_mat_impl.o psb_z_base_mat_impl.o
 #\
   psb_s_lbase_mat_impl.o psb_d_lbase_mat_impl.o psb_c_lbase_mat_impl.o psb_z_lbase_mat_impl.o 
-SOBJS=psb_s_csr_impl.o psb_s_coo_impl.o psb_s_csc_impl.o psb_s_mat_impl.o
+SOBJS=psb_s_csr_impl.o psb_s_coo_impl.o psb_s_csc_impl.o psb_s_mat_impl.o\
+ psb_s_rb_idx_tree_impl.o
 #\
  psb_s_lcoo_impl.o psb_s_lcsr_impl.o 
-DOBJS=psb_d_csr_impl.o psb_d_coo_impl.o psb_d_csc_impl.o psb_d_mat_impl.o psb_d_rb_idx_tree_impl.o
+DOBJS=psb_d_csr_impl.o psb_d_coo_impl.o psb_d_csc_impl.o psb_d_mat_impl.o\
+ psb_d_rb_idx_tree_impl.o
 #\
  psb_d_lcoo_impl.o  psb_d_lcsr_impl.o 
-COBJS=psb_c_csr_impl.o psb_c_coo_impl.o psb_c_csc_impl.o psb_c_mat_impl.o
+COBJS=psb_c_csr_impl.o psb_c_coo_impl.o psb_c_csc_impl.o psb_c_mat_impl.o\
+ psb_c_rb_idx_tree_impl.o
 #\
  psb_c_lcoo_impl.o  psb_c_lcsr_impl.o 
-ZOBJS=psb_z_csr_impl.o psb_z_coo_impl.o psb_z_csc_impl.o psb_z_mat_impl.o
+ZOBJS=psb_z_csr_impl.o psb_z_coo_impl.o psb_z_csc_impl.o psb_z_mat_impl.o\
+ psb_z_rb_idx_tree_impl.o
 #\
  psb_z_lcoo_impl.o  psb_z_lcsr_impl.o 
 

base/serial/impl/psb_c_csr_impl.F90

@@ -3654,6 +3654,7 @@ subroutine  psb_c_csr_clean_zeros(a, info)
   call a%set_host()
 end subroutine psb_c_csr_clean_zeros
 
+#if 0
 subroutine psb_ccsrspspmm(a,b,c,info)
   use psb_c_mat_mod
   use psb_serial_mod, psb_protect_name => psb_ccsrspspmm
@@ -3776,7 +3777,538 @@ contains
   end subroutine csr_spspmm
 
 end subroutine psb_ccsrspspmm
+#else
+subroutine psb_ccsrspspmm(a,b,c,info)
+  use psb_c_mat_mod
+  use psb_serial_mod, psb_protect_name => psb_ccsrspspmm
+
+  implicit none
+
+  class(psb_c_csr_sparse_mat), intent(in) :: a,b
+  type(psb_c_csr_sparse_mat), intent(out)  :: c
+  integer(psb_ipk_), intent(out)                     :: info
+  integer(psb_ipk_) :: ma,na,mb,nb, nzc, nza, nzb
+  character(len=20) :: name
+  integer(psb_ipk_) :: err_act
+  name='psb_csrspspmm'
+  call psb_erractionsave(err_act)
+  info = psb_success_
+
+  if (a%is_dev())   call a%sync()
+  if (b%is_dev())   call b%sync()
+
+  ma = a%get_nrows()
+  na = a%get_ncols()
+  mb = b%get_nrows()
+  nb = b%get_ncols()
+
+
+  if ( mb /= na ) then
+    write(psb_err_unit,*) 'Mismatch in SPSPMM: ',ma,na,mb,nb
+    info = psb_err_invalid_matrix_sizes_
+    call psb_errpush(info,name)
+    goto 9999
+  endif
+
+  select case(spspmm_impl)
+  case (spspmm_serial)
+    ! Estimate number of nonzeros on output.
+    nza = a%get_nzeros()
+    nzb = b%get_nzeros()
+    nzc = 2*(nza+nzb)
+    call c%allocate(ma,nb,nzc)
+
+    call csr_spspmm(a,b,c,info)
+  case (spspmm_omp_gustavson)
+    call spmm_omp_gustavson(a,b,c,info)
+  case (spspmm_omp_gustavson_1d)
+    call spmm_omp_gustavson_1d(a,b,c,info)
+  case (spspmm_serial_rb_tree)
+    call spmm_serial_rb_tree(a,b,c,info)
+  case (spspmm_omp_rb_tree)
+    call spmm_omp_rb_tree(a,b,c,info)
+  case (spspmm_omp_two_pass)
+    call spmm_omp_two_pass(a,b,c,info)
+  case default
+    write(psb_err_unit,*) 'Unknown spspmm implementation'
+    ! push error
+    goto 9999
+  end select
+
+  call c%set_asb()
+  call c%set_host()
+
+  call psb_erractionrestore(err_act)
+  return
+
+9999 call psb_error_handler(err_act)
+
+  return
+
+contains
+
+  subroutine csr_spspmm(a,b,c,info)
+    implicit none
+    type(psb_c_csr_sparse_mat), intent(in)  :: a,b
+    type(psb_c_csr_sparse_mat), intent(inout) :: c
+    integer(psb_ipk_), intent(out)          :: info
+    integer(psb_ipk_)              :: ma,na,mb,nb
+    integer(psb_ipk_), allocatable :: irow(:), idxs(:)
+    complex(psb_spk_), allocatable    :: row(:)
+    integer(psb_ipk_)              :: i,j,k,irw,icl,icf, iret, &
+         & nzc,nnzre, isz, ipb, irwsz, nrc, nze
+    complex(psb_spk_)                 :: cfb
+
+
+    info = psb_success_
+    ma = a%get_nrows()
+    na = a%get_ncols()
+    mb = b%get_nrows()
+    nb = b%get_ncols()
 
+    nze = min(size(c%val),size(c%ja))
+    isz = max(ma,na,mb,nb)
+    call psb_realloc(isz,row,info)
+    if (info == 0) call psb_realloc(isz,idxs,info)
+    if (info == 0) call psb_realloc(isz,irow,info)
+    if (info /= 0) return
+    row  = dzero
+    irow = 0
+    nzc  = 1
+    do j = 1,ma
+      c%irp(j) = nzc
+      nrc = 0
+      do k = a%irp(j), a%irp(j+1)-1
+        irw = a%ja(k)
+        cfb = a%val(k)
+        irwsz = b%irp(irw+1)-b%irp(irw)
+        do i = b%irp(irw),b%irp(irw+1)-1
+          icl = b%ja(i)
+          if (irow(icl)<j) then
+            nrc = nrc + 1
+            idxs(nrc) = icl
+            irow(icl) = j
+          end if
+          row(icl)  = row(icl)  + cfb*b%val(i)
+        end do
+      end do
+      if (nrc > 0 ) then
+        if ((nzc+nrc)>nze) then
+          nze = max(ma*((nzc+j-1)/j),nzc+2*nrc)
+          call psb_realloc(nze,c%val,info)
+          if (info == 0) call psb_realloc(nze,c%ja,info)
+          if (info /= 0) return
+        end if
+
+        call psb_qsort(idxs(1:nrc))
+        do i=1, nrc
+          irw        = idxs(i)
+          c%ja(nzc)  = irw
+          c%val(nzc) = row(irw)
+          row(irw)   = dzero
+          nzc        = nzc + 1
+        end do
+      end if
+    end do
+
+    c%irp(ma+1) = nzc
+  end subroutine csr_spspmm
+
+  ! gustavson's algorithm using perfect hashing 
+  ! and OpenMP parallelisation
+  subroutine spmm_omp_gustavson(a,b,c,info)
+    use omp_lib
+
+    implicit none
+    type(psb_c_csr_sparse_mat), intent(in) :: a,b
+    type(psb_c_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    complex(psb_spk_), allocatable :: vals(:), acc(:)
+    integer(psb_ipk_)   :: ma, nb
+    integer(psb_ipk_), allocatable :: col_inds(:), offsets(:)
+    integer(psb_ipk_)   :: irw, jj, j, k, nnz, rwnz, thread_upperbound, start_idx, end_idx
+
+    ma = a%get_nrows()
+    nb = b%get_ncols()
+
+    call c%allocate(ma, nb)
+    c%irp(1) = 1
+
+    ! dense accumulator
+    ! https://sc18.supercomputing.org/proceedings/workshops/workshop_files/ws_lasalss115s2-file1.pdf
+    call psb_realloc(nb, acc, info)
+
+    allocate(offsets(omp_get_max_threads()))
+    !$omp parallel private(vals,col_inds,nnz,rwnz,thread_upperbound,acc,start_idx,end_idx) &
+    !$omp shared(a,b,c,offsets) 
+    thread_upperbound = 0
+    start_idx = 0
+    !$omp do schedule(static) private(irw, jj, j)
+    do irw = 1, ma
+      if (start_idx == 0) then
+        start_idx = irw
+      end if
+      end_idx = irw
+      do jj = a%irp(irw), a%irp(irw + 1) - 1
+        j = a%ja(jj)
+        thread_upperbound = thread_upperbound + b%irp(j+1) - b%irp(j)
+      end do
+    end do
+    !$omp end do
+
+    call psb_realloc(thread_upperbound, vals, info)
+    call psb_realloc(thread_upperbound, col_inds, info)
+
+    ! possible bottleneck
+    acc = 0
+
+    nnz = 0
+    !$omp do schedule(static) private(irw, jj, j, k)
+    do irw = 1, ma
+      rwnz = 0
+      do jj = a%irp(irw), a%irp(irw + 1) - 1
+        j = a%ja(jj)
+        do k = b%irp(j), b%irp(j + 1) - 1
+          if (acc(b%ja(k)) == 0) then
+            nnz = nnz + 1
+            rwnz = rwnz + 1
+            col_inds(nnz) =  b%ja(k)
+          end if
+          acc(b%ja(k)) = acc(b%ja(k)) + a%val(jj) * b%val(k) 
+        end do
+      end do
+      call psb_qsort(col_inds(nnz - rwnz + 1:nnz))
+
+      do k = nnz - rwnz + 1, nnz
+        vals(k) = acc(col_inds(k))
+        acc(col_inds(k)) = 0
+      end do
+      c%irp(irw + 1) = rwnz
+    end do
+    !$omp end do
+
+    offsets(omp_get_thread_num() + 1) = nnz
+    !$omp barrier
+
+    ! possible bottleneck
+    !$omp single
+    do k = 1, omp_get_num_threads() - 1
+      offsets(k + 1) = offsets(k + 1) + offsets(k)
+    end do
+    !$omp end single
+
+    !$omp barrier
+
+    if (omp_get_thread_num() /= 0) then
+      c%irp(start_idx) = offsets(omp_get_thread_num()) + 1
+    end if
+
+    do irw = start_idx, end_idx - 1
+      c%irp(irw + 1) = c%irp(irw + 1) + c%irp(irw)
+    end do
+
+    !$omp barrier
+
+    !$omp single
+    c%irp(ma + 1) = c%irp(ma + 1) + c%irp(ma)
+    call psb_realloc(c%irp(ma + 1), c%val, info)        
+    call psb_realloc(c%irp(ma + 1), c%ja, info)
+    !$omp end single
+
+    c%val(c%irp(start_idx):c%irp(end_idx + 1) - 1) = vals(1:nnz)
+    c%ja(c%irp(start_idx):c%irp(end_idx + 1) - 1) = col_inds(1:nnz)
+    !$omp end parallel
+  end subroutine spmm_omp_gustavson
+
+  subroutine spmm_omp_gustavson_1d(a,b,c,info)
+    use omp_lib
+
+    implicit none
+    type(psb_c_csr_sparse_mat), intent(in) :: a,b
+    type(psb_c_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    complex(psb_spk_), allocatable :: vals(:), acc(:)
+    integer(psb_ipk_)   :: ma, nb
+    integer(psb_ipk_), allocatable :: col_inds(:), offsets(:)
+    integer(psb_ipk_)   :: irw, jj, j, k, nnz, rwnz, thread_upperbound, &
+         start_idx, end_idx , blk, blk_size, rwstart,&
+         rwblk, rwblkrem, nblks
+
+    ma = a%get_nrows()
+    nb = b%get_ncols()
+
+    call c%allocate(ma, nb)
+    c%irp(1) = 1
+
+    ! dense accumulator
+    ! https://sc18.supercomputing.org/proceedings/workshops/workshop_files/ws_lasalss115s2-file1.pdf
+    call psb_realloc(nb, acc, info)
+    allocate(offsets(omp_get_max_threads()))
+
+    nblks = 4 * omp_get_max_threads()
+    rwblk = (ma / nblks)
+    rwblkrem = modulo(ma, nblks)
+    !$omp parallel private(vals,col_inds,nnz,thread_upperbound,acc,start_idx,end_idx) shared(a,b,c,offsets)
+    thread_upperbound = 0
+    start_idx = 0
+    !$omp do schedule(static) private(irw, jj, j)
+    do irw = 1, ma
+      do jj = a%irp(irw), a%irp(irw + 1) - 1
+        j = a%ja(jj)
+        thread_upperbound = thread_upperbound + b%irp(j+1) - b%irp(j)
+      end do
+    end do
+    !$omp end do
+
+    call psb_realloc(thread_upperbound, vals, info)
+    call psb_realloc(thread_upperbound, col_inds, info)
+
+    ! possible bottleneck
+    acc = 0
+
+    nnz = 0
+    !$omp do schedule(static) private(irw,jj,j,k,rwnz,blk,blk_size,rwstart)
+    do blk = 0, nblks - 1
+      if (blk < rwblkrem) then
+        blk_size = rwblk + 1
+        rwstart = blk * rwblk + blk + 1
+      else
+        blk_size = rwblk
+        rwstart = blk * rwblk &
+             + rwblkrem + 1
+      end if
+      do irw = rwstart, rwstart + blk_size - 1
+        if (start_idx == 0) then
+          start_idx = irw
+        end if
+        end_idx = irw
+        rwnz = 0
+        do jj = a%irp(irw), a%irp(irw + 1) - 1
+          j = a%ja(jj)
+          do k = b%irp(j), b%irp(j + 1) - 1
+            if (acc(b%ja(k)) == 0) then
+              nnz = nnz + 1
+              rwnz = rwnz + 1
+              col_inds(nnz) =  b%ja(k)
+            end if
+            acc(b%ja(k)) = acc(b%ja(k)) + a%val(jj) * b%val(k) 
+          end do
+        end do
+        call psb_qsort(col_inds(nnz - rwnz + 1:nnz))
+
+        do k = nnz - rwnz + 1, nnz
+          vals(k) = acc(col_inds(k))
+          acc(col_inds(k)) = 0
+        end do
+        c%irp(irw + 1) = rwnz
+      end do
+    end do
+    !$omp end do
+
+    offsets(omp_get_thread_num() + 1) = nnz
+    !$omp barrier
+
+    ! possible bottleneck
+    !$omp single
+    do k = 1, omp_get_num_threads() - 1
+      offsets(k + 1) = offsets(k + 1) + offsets(k)
+    end do
+    !$omp end single
+
+    !$omp barrier
+
+    if (omp_get_thread_num() /= 0) then
+      c%irp(start_idx) = offsets(omp_get_thread_num()) + 1
+    end if
+
+    do irw = start_idx, end_idx - 1
+      c%irp(irw + 1) = c%irp(irw + 1) + c%irp(irw)
+    end do
+
+    !$omp barrier
+
+    !$omp single
+    c%irp(ma + 1) = c%irp(ma + 1) + c%irp(ma)
+    call psb_realloc(c%irp(ma + 1), c%val, info)        
+    call psb_realloc(c%irp(ma + 1), c%ja, info)
+    !$omp end single
+
+    c%val(c%irp(start_idx):c%irp(end_idx + 1) - 1) = vals(1:nnz)
+    c%ja(c%irp(start_idx):c%irp(end_idx + 1) - 1) = col_inds(1:nnz)
+    !$omp end parallel
+  end subroutine spmm_omp_gustavson_1d
+
+  subroutine spmm_serial_rb_tree(a,b,c,info)
+    use psb_rb_idx_tree_mod
+    implicit none
+    type(psb_c_csr_sparse_mat), intent(in) :: a,b
+    type(psb_c_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    integer(psb_ipk_)   :: a_m, b_n
+    integer(psb_ipk_)   :: row, col
+    type(psb_c_rb_idx_tree), allocatable :: row_accs(:)
+
+    a_m = a%get_nrows()
+    b_n = b%get_ncols()
+
+    allocate(row_accs(a_m))
+    call c%allocate(a_m, b_n)
+
+    do row = 1, a_m
+      row_accs(row)%nnz = 0
+      nullify(row_accs(row)%root)
+      do col = a%irp(row), a%irp(row + 1) - 1
+        call psb_rb_idx_tree_scalar_sparse_row_mul(row_accs(row), a%val(col), b, a%ja(col))
+      end do
+    end do
+    call psb_rb_idx_tree_merge(row_accs, c)
+
+    deallocate(row_accs)
+
+    info = 0
+  end subroutine spmm_serial_rb_tree
+
+  subroutine spmm_omp_rb_tree(a,b,c,info)
+    use omp_lib
+    use psb_rb_idx_tree_mod
+    implicit none
+    type(psb_c_csr_sparse_mat), intent(in) :: a,b
+    type(psb_c_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    integer(psb_ipk_)   :: a_m, b_n
+    integer(psb_ipk_)   :: row, col
+    type(psb_c_rb_idx_tree), allocatable :: row_accs(:)
+    real(8) :: tic, toc
+
+    a_m = a%get_nrows()
+    b_n = b%get_ncols()
+
+    call c%allocate(a_m, b_n)
+
+    allocate(row_accs(a_m))
+    call c%allocate(a_m, b_n)
+
+    !$omp parallel do schedule(static)
+    do row = 1, a_m
+      row_accs(row)%nnz = 0
+      nullify(row_accs(row)%root)
+      do col = a%irp(row), a%irp(row + 1) - 1
+        call psb_rb_idx_tree_scalar_sparse_row_mul(row_accs(row), a%val(col), b, a%ja(col))
+      end do
+    end do
+    !$omp end parallel do
+
+    call psb_rb_idx_tree_merge(row_accs, c)
+
+    deallocate(row_accs)
+    info = 0
+  end subroutine spmm_omp_rb_tree
+
+  subroutine compute_indices(a, b, c, info)
+    implicit none
+    type(psb_c_csr_sparse_mat), intent(in) :: a,b
+    type(psb_c_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    integer :: full_mat_bound
+    integer :: row, col, i, j, k, nnz
+
+    full_mat_bound = 0
+    !omp parallel do schedule(static) reduction(+:full_mat_bound)
+    do row = 1, a%get_nrows()
+      do col = a%irp(row), a%irp(row + 1) - 1
+        j = a%ja(col)
+        full_mat_bound = full_mat_bound + b%irp(j+1) - b%irp(j)
+      end do
+    end do
+    !omp end parallel do
+
+    call psb_realloc(a%get_nrows() + 1, c%irp, info)
+    call psb_realloc(full_mat_bound, c%ja, info)
+    c%ja = 0
+    c%irp(1) = 1
+
+    nnz = 0
+
+    do row = 1, a%get_nrows()
+      do col = a%irp(row), a%irp(row + 1) - 1
+        do i = b%irp(a%ja(col)), b%irp(a%ja(col) + 1) - 1
+          k = 0
+          do while(c%ja(c%irp(row) + k) /= 0 .and. c%ja(c%irp(row) + k) /= b%ja(i))
+            k = k + 1
+          end do
+          if (c%ja(c%irp(row) + k) == 0) then
+            c%ja(c%irp(row)+k) = b%ja(i)
+            nnz = nnz + 1
+          end if
+        end do
+      end do
+      c%irp(row + 1) = nnz + 1
+      call psb_qsort(c%ja(c%irp(row):c%irp(row + 1)-1))
+    end do
+
+
+    call psb_realloc(nnz, c%ja, info)
+    call psb_realloc(nnz, c%val, info)
+
+    c%val = 0
+  end subroutine compute_indices
+
+  subroutine direct_scalar_sparse_row_mul(out_mat, out_row_num, scalar, mat, trgt_row_num)
+    type(psb_c_csr_sparse_mat), intent(inout) :: out_mat
+    integer(psb_ipk_), intent(in) :: out_row_num
+    complex(psb_spk_), intent(in) :: scalar
+    type(psb_c_csr_sparse_mat), intent(in) :: mat
+    integer(psb_ipk_), intent(in) :: trgt_row_num
+
+    integer(psb_ipk_) :: i, k, row_start, row_end
+
+    row_start = out_mat%irp(out_row_num)
+    row_end = out_mat%irp(out_row_num + 1) - 1
+
+    do i = mat%irp(trgt_row_num), mat%irp(trgt_row_num + 1) - 1
+      do k = out_mat%irp(out_row_num), out_mat%irp(out_row_num + 1) - 1
+        if (out_mat%ja(k) == mat%ja(i)) then
+          out_mat%val(k) = out_mat%val(k) + scalar * mat%val(i)
+          exit
+        end if
+      end do
+    end do
+
+  end subroutine direct_scalar_sparse_row_mul
+
+  subroutine spmm_omp_two_pass(a,b,c,info)
+    use omp_lib
+
+    implicit none
+    type(psb_c_csr_sparse_mat), intent(in) :: a,b
+    type(psb_c_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    integer(psb_ipk_)   :: a_m, b_n, row, col
+
+    a_m = a%get_nrows()
+    b_n = b%get_ncols()
+
+    call c%allocate(a_m, b_n)
+
+    call compute_indices(a, b, c, info)
+
+    !$omp parallel do schedule(static)
+    do row = 1, a_m
+      do col = a%irp(row), a%irp(row + 1) - 1
+        call direct_scalar_sparse_row_mul(c, row, a%val(col), b, a%ja(col))
+      end do
+    end do
+    !$omp end parallel do
+  end subroutine spmm_omp_two_pass
+
+end subroutine psb_ccsrspspmm
+#endif
 
 !
 !

base/serial/impl/psb_c_rb_idx_tree_impl.F90

@@ -0,0 +1,329 @@
+!
+!                Parallel Sparse BLAS  version 3.5
+!      (C) Copyright 2006-2018
+!        Salvatore Filippone
+!        Alfredo Buttari
+!
+!    Redistribution and use in source and binary forms, with or without
+!    modification, are permitted provided that the following conditions
+!    are met:
+!      1. Redistributions of source code must retain the above copyright
+!         notice, this list of conditions and the following disclaimer.
+!      2. Redistributions in binary form must reproduce the above copyright
+!         notice, this list of conditions, and the following disclaimer in the
+!         documentation and/or other materials provided with the distribution.
+!      3. The name of the PSBLAS group or the names of its contributors may
+!         not be used to endorse or promote products derived from this
+!         software without specific written permission.
+!
+!    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+!    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+!    TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+!    PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE PSBLAS GROUP OR ITS CONTRIBUTORS
+!    BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+!    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+!    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+!    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+!    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+!    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+!    POSSIBILITY OF SUCH DAMAGE.
+!
+!
+!
+! package: psb_c_rb_idx_tree_impl
+! 
+! Red black tree implementation ordered by index
+!
+! Each node contains and index and a double precision value
+!
+! The tree should always be well balanced
+!
+! inserting a node with an existing index will 
+! add up the new value to the old one
+! Contributed by Dimitri Walther
+! 
+subroutine psb_c_rb_idx_tree_insert(this, idx, val)
+  use psb_c_rb_idx_tree_mod, psb_protect_name => psb_c_rb_idx_tree_insert
+  implicit none
+  class(psb_c_rb_idx_tree), intent(inout) :: this
+  integer(psb_ipk_), intent(in) :: idx
+  complex(psb_spk_), intent(in) :: val
+
+  character(len=22) :: name
+  type(psb_c_rb_idx_node), pointer :: new_node
+  type(psb_c_rb_idx_node), pointer :: current, previous
+  name='psb_rb_idx_tree_insert'
+
+  allocate(new_node)
+  new_node%idx = idx
+  new_node%val = val
+  nullify(new_node%left)
+  nullify(new_node%right)
+  nullify(new_node%parent)
+  new_node%is_red = .true.
+
+
+  if (.not. associated(this%root)) then
+    this%root => new_node
+    this%nnz = 1
+    new_node%is_red = .false.
+    return
+  end if
+
+  current => this%root
+
+  do while (associated(current))
+    previous => current
+
+    if (idx == current%idx) then
+      current%val = current%val + val
+      deallocate(new_node)
+      return
+    else if (idx < current%idx) then
+      current => current%left
+    else
+
+      current => current%right
+    end if
+  end do
+
+  if (idx < previous%idx) then
+    new_node%parent => previous
+    previous%left => new_node
+  else
+    new_node%parent => previous
+    previous%right => new_node
+  end if
+
+  call psb_c_rb_idx_tree_fix_insertion(this, new_node)
+
+  this%nnz = this%nnz + 1
+end subroutine psb_c_rb_idx_tree_insert
+
+subroutine psb_c_rb_idx_tree_fix_insertion(this, node)
+  use psb_c_rb_idx_tree_mod, psb_protect_name => psb_c_rb_idx_tree_fix_insertion
+  implicit none
+  class(psb_c_rb_idx_tree), intent(inout) :: this
+  type(psb_c_rb_idx_node), pointer, intent(inout) :: node
+
+  character(len=29) :: name
+  type(psb_c_rb_idx_node), pointer :: current, parent, grand_parent, uncle
+  name = 'psb_rb_idx_tree_fix_insertion'
+
+  current => node
+  parent => current%parent
+  do while(associated(parent) .and. parent%is_red)
+    ! grand parent exist because root can't be red
+    grand_parent => parent%parent
+    if (parent%idx < grand_parent%idx) then
+      uncle => grand_parent%right
+    else
+      uncle => grand_parent%left
+    end if
+
+    if (associated(uncle) .and. uncle%is_red) then
+      parent%is_red = .false.
+      uncle%is_red = .false.
+      grand_parent%is_red = .true.
+      current => grand_parent
+      parent => current%parent
+
+      ! Left-Left case
+    else if (current%idx < parent%idx .and. &
+         parent%idx < grand_parent%idx) then
+      call psb_c_rb_idx_tree_rotate_right(grand_parent)
+      call psb_c_rb_idx_tree_swap_colors(parent, grand_parent)
+
+      if (this%root%idx == grand_parent%idx) this%root => parent
+
+      return
+      ! Left-Right case
+    else if (current%idx > parent%idx .and. &
+         parent%idx < grand_parent%idx) then
+      call psb_c_rb_idx_tree_rotate_left(parent)
+      call psb_c_rb_idx_tree_rotate_right(grand_parent)
+      call psb_c_rb_idx_tree_swap_colors(current, grand_parent)
+
+      if (this%root%idx == grand_parent%idx) this%root => current
+
+      return
+      ! Right-Right case
+    else if (current%idx > parent%idx .and. &
+         parent%idx > grand_parent%idx) then
+      call psb_c_rb_idx_tree_rotate_left(grand_parent)
+      call psb_c_rb_idx_tree_swap_colors(parent, grand_parent)
+
+      if (this%root%idx == grand_parent%idx) this%root => parent
+
+      return
+      ! Right-Left case
+    else
+      call psb_c_rb_idx_tree_rotate_right(parent)
+      call psb_c_rb_idx_tree_rotate_left(grand_parent)
+      call psb_c_rb_idx_tree_swap_colors(current, grand_parent)
+
+      if (this%root%idx == grand_parent%idx) this%root => current
+
+      return
+    end if
+  end do
+
+  this%root%is_red = .false.
+end subroutine psb_c_rb_idx_tree_fix_insertion
+
+subroutine psb_c_rb_idx_tree_swap_colors(n1, n2)
+  use psb_c_rb_idx_tree_mod, psb_protect_name => psb_c_rb_idx_tree_swap_colors
+  implicit none
+  type(psb_c_rb_idx_node), pointer, intent(inout) :: n1, n2
+
+  character(len=27) :: name
+  logical :: tmp
+  name='psb_rb_idx_tree_swap_colors'
+
+  tmp = n1%is_red
+  n1%is_red = n2%is_red
+  n2%is_red = tmp
+end subroutine psb_c_rb_idx_tree_swap_colors
+
+subroutine psb_c_rb_idx_tree_rotate_right(node)
+  use psb_c_rb_idx_tree_mod, psb_protect_name => psb_c_rb_idx_tree_rotate_right
+  implicit none
+  type(psb_c_rb_idx_node), pointer, intent(inout) :: node
+
+  character(len=28) :: name
+  type(psb_c_rb_idx_node), pointer :: l, lr
+  name='psb_rb_idx_tree_rotate_right'
+
+  if (.not. associated(node%left)) return
+
+  l => node%left
+  lr => l%right
+  node%left => lr
+
+  if (associated(lr)) lr%parent => node
+
+  if (associated(node%parent)) then
+    if (node%idx < node%parent%idx) then
+      node%parent%left => l
+    else
+      node%parent%right => l
+    end if
+  end if
+
+  l%parent => node%parent
+  node%parent => l
+
+  l%right => node
+end subroutine psb_c_rb_idx_tree_rotate_right
+
+subroutine psb_c_rb_idx_tree_rotate_left(node)
+  use psb_c_rb_idx_tree_mod, psb_protect_name => psb_c_rb_idx_tree_rotate_left
+  implicit none
+  type(psb_c_rb_idx_node), pointer, intent(inout) :: node
+
+  character(len=27) :: name
+  type(psb_c_rb_idx_node), pointer :: r, rl
+  name='psb_rb_idx_tree_rotate_left'
+
+  if (.not. associated(node%right)) return
+
+  r => node%right
+  rl => r%left
+  node%right => rl
+
+  if (associated(rl)) rl%parent => node
+
+  if (associated(node%parent)) then
+    if (node%idx < node%parent%idx) then
+      node%parent%left => r
+    else
+      node%parent%right => r
+    end if
+  end if
+
+  r%parent => node%parent
+  node%parent => r
+
+  r%left => node
+end subroutine psb_c_rb_idx_tree_rotate_left
+
+subroutine psb_c_rb_idx_tree_scalar_sparse_row_mul(tree, scalar, mat, row_num)
+  use psb_c_rb_idx_tree_mod, psb_protect_name => psb_c_rb_idx_tree_scalar_sparse_row_mul
+  use psb_c_csr_mat_mod, only : psb_c_csr_sparse_mat
+  implicit none
+  type(psb_c_rb_idx_tree), intent(inout) :: tree
+  complex(psb_spk_), intent(in) :: scalar
+  type(psb_c_csr_sparse_mat), intent(in) :: mat
+  integer(psb_ipk_), intent(in) :: row_num
+
+  character(len=37) :: name
+  integer(psb_ipk_) :: i
+  name='psb_rb_idx_tree_scalar_sparse_row_mul'
+
+  do i = mat%irp(row_num), mat%irp(row_num + 1) - 1
+    call tree%insert(mat%ja(i),scalar * mat%val(i))
+  end do
+
+end subroutine psb_c_rb_idx_tree_scalar_sparse_row_mul
+
+subroutine psb_c_rb_idx_tree_merge(trees, mat)
+#if defined(OPENMP)
+  use omp_lib
+#endif
+  use psb_realloc_mod
+  use psb_c_rb_idx_tree_mod, psb_protect_name => psb_c_rb_idx_tree_merge
+  use psb_c_csr_mat_mod, only : psb_c_csr_sparse_mat
+  implicit none
+  type(psb_c_rb_idx_tree), allocatable, intent(inout) :: trees(:)
+  type(psb_c_csr_sparse_mat), intent(inout) :: mat
+
+  character(len=21) :: name
+  integer(psb_ipk_) :: i, j, rows, info, nnz
+  type(psb_c_rb_idx_node), pointer :: current, previous
+  name='psb_rb_idx_tree_merge'
+
+  rows = size(trees)
+
+  mat%irp(1) = 1
+
+  do i=1, rows
+    mat%irp(i + 1) = mat%irp(i) + trees(i)%nnz
+  end do
+
+  nnz = mat%irp(rows + 1)
+  call psb_realloc(nnz, mat%val, info)
+  call psb_realloc(nnz, mat%ja, info)
+
+#if defined(OPENMP)
+  !$omp parallel do schedule(static), private(current, previous, j)
+#endif
+  do i = 1, size(trees)
+    j = 0
+    current => trees(i)%root
+    do while(associated(current))
+      ! go to the left-most node
+      do while(associated(current%left))
+        current => current%left
+      end do
+      mat%val(j + mat%irp(i)) = current%val
+      mat%ja(j + mat%irp(i)) = current%idx
+      j = j + 1
+
+      previous => current
+      if (associated(current%right)) then
+        if (associated(current%parent)) then
+          current%parent%left => current%right
+        end if
+        current%right%parent => current%parent
+        current => current%right
+      else
+        current => current%parent
+        if (associated(current)) nullify(current%left)
+      end if
+      deallocate(previous)
+    end do
+  end do
+#if defined(OPENMP)
+  !$omp end parallel do
+#endif
+end subroutine psb_c_rb_idx_tree_merge

base/serial/impl/psb_d_csr_impl.F90

@@ -3654,6 +3654,130 @@ subroutine  psb_d_csr_clean_zeros(a, info)
   call a%set_host()
 end subroutine psb_d_csr_clean_zeros
 
+#if 0
+subroutine psb_dcsrspspmm(a,b,c,info)
+  use psb_d_mat_mod
+  use psb_serial_mod, psb_protect_name => psb_dcsrspspmm
+
+  implicit none
+
+  class(psb_d_csr_sparse_mat), intent(in) :: a,b
+  type(psb_d_csr_sparse_mat), intent(out)  :: c
+  integer(psb_ipk_), intent(out)                     :: info
+  integer(psb_ipk_) :: ma,na,mb,nb, nzc, nza, nzb
+  character(len=20) :: name
+  integer(psb_ipk_) :: err_act
+  name='psb_csrspspmm'
+  call psb_erractionsave(err_act)
+  info = psb_success_
+
+  if (a%is_dev())   call a%sync()
+  if (b%is_dev())   call b%sync()
+
+  ma = a%get_nrows()
+  na = a%get_ncols()
+  mb = b%get_nrows()
+  nb = b%get_ncols()
+
+
+  if ( mb /= na ) then
+    write(psb_err_unit,*) 'Mismatch in SPSPMM: ',ma,na,mb,nb
+    info = psb_err_invalid_matrix_sizes_
+    call psb_errpush(info,name)
+    goto 9999
+  endif
+
+  ! Estimate number of nonzeros on output.
+  nza = a%get_nzeros()
+  nzb = b%get_nzeros()
+  nzc = 2*(nza+nzb)
+  call c%allocate(ma,nb,nzc)
+
+  call csr_spspmm(a,b,c,info)
+
+  call c%set_asb()
+  call c%set_host()
+
+  call psb_erractionrestore(err_act)
+  return
+
+9999 call psb_error_handler(err_act)
+
+  return
+
+contains
+
+  subroutine csr_spspmm(a,b,c,info)
+    implicit none
+    type(psb_d_csr_sparse_mat), intent(in)  :: a,b
+    type(psb_d_csr_sparse_mat), intent(inout) :: c
+    integer(psb_ipk_), intent(out)          :: info
+    integer(psb_ipk_)              :: ma,na,mb,nb
+    integer(psb_ipk_), allocatable :: irow(:), idxs(:)
+    real(psb_dpk_), allocatable    :: row(:)
+    integer(psb_ipk_)              :: i,j,k,irw,icl,icf, iret, &
+         & nzc,nnzre, isz, ipb, irwsz, nrc, nze
+    real(psb_dpk_)                 :: cfb
+
+
+    info = psb_success_
+    ma = a%get_nrows()
+    na = a%get_ncols()
+    mb = b%get_nrows()
+    nb = b%get_ncols()
+
+    nze = min(size(c%val),size(c%ja))
+    isz = max(ma,na,mb,nb)
+    call psb_realloc(isz,row,info)
+    if (info == 0) call psb_realloc(isz,idxs,info)
+    if (info == 0) call psb_realloc(isz,irow,info)
+    if (info /= 0) return
+    row  = dzero
+    irow = 0
+    nzc  = 1
+    do j = 1,ma
+      c%irp(j) = nzc
+      nrc = 0
+      do k = a%irp(j), a%irp(j+1)-1
+        irw = a%ja(k)
+        cfb = a%val(k)
+        irwsz = b%irp(irw+1)-b%irp(irw)
+        do i = b%irp(irw),b%irp(irw+1)-1
+          icl = b%ja(i)
+          if (irow(icl)<j) then
+            nrc = nrc + 1
+            idxs(nrc) = icl
+            irow(icl) = j
+          end if
+          row(icl)  = row(icl)  + cfb*b%val(i)
+        end do
+      end do
+      if (nrc > 0 ) then
+        if ((nzc+nrc)>nze) then
+          nze = max(ma*((nzc+j-1)/j),nzc+2*nrc)
+          call psb_realloc(nze,c%val,info)
+          if (info == 0) call psb_realloc(nze,c%ja,info)
+          if (info /= 0) return
+        end if
+
+        call psb_qsort(idxs(1:nrc))
+        do i=1, nrc
+          irw        = idxs(i)
+          c%ja(nzc)  = irw
+          c%val(nzc) = row(irw)
+          row(irw)   = dzero
+          nzc        = nzc + 1
+        end do
+      end if
+    end do
+
+    c%irp(ma+1) = nzc
+
+
+  end subroutine csr_spspmm
+
+end subroutine psb_dcsrspspmm
+#else
 subroutine psb_dcsrspspmm(a,b,c,info)
   use psb_d_mat_mod
   use psb_serial_mod, psb_protect_name => psb_dcsrspspmm
@@ -4184,7 +4308,7 @@ subroutine spmm_omp_two_pass(a,b,c,info)
   end subroutine spmm_omp_two_pass
 
 end subroutine psb_dcsrspspmm
-
+#endif
 
 !
 !

base/serial/impl/psb_s_csr_impl.F90

@@ -3654,6 +3654,7 @@ subroutine  psb_s_csr_clean_zeros(a, info)
   call a%set_host()
 end subroutine psb_s_csr_clean_zeros
 
+#if 0
 subroutine psb_scsrspspmm(a,b,c,info)
   use psb_s_mat_mod
   use psb_serial_mod, psb_protect_name => psb_scsrspspmm
@@ -3776,7 +3777,538 @@ contains
   end subroutine csr_spspmm
 
 end subroutine psb_scsrspspmm
+#else
+subroutine psb_scsrspspmm(a,b,c,info)
+  use psb_s_mat_mod
+  use psb_serial_mod, psb_protect_name => psb_scsrspspmm
+
+  implicit none
+
+  class(psb_s_csr_sparse_mat), intent(in) :: a,b
+  type(psb_s_csr_sparse_mat), intent(out)  :: c
+  integer(psb_ipk_), intent(out)                     :: info
+  integer(psb_ipk_) :: ma,na,mb,nb, nzc, nza, nzb
+  character(len=20) :: name
+  integer(psb_ipk_) :: err_act
+  name='psb_csrspspmm'
+  call psb_erractionsave(err_act)
+  info = psb_success_
+
+  if (a%is_dev())   call a%sync()
+  if (b%is_dev())   call b%sync()
+
+  ma = a%get_nrows()
+  na = a%get_ncols()
+  mb = b%get_nrows()
+  nb = b%get_ncols()
+
+
+  if ( mb /= na ) then
+    write(psb_err_unit,*) 'Mismatch in SPSPMM: ',ma,na,mb,nb
+    info = psb_err_invalid_matrix_sizes_
+    call psb_errpush(info,name)
+    goto 9999
+  endif
+
+  select case(spspmm_impl)
+  case (spspmm_serial)
+    ! Estimate number of nonzeros on output.
+    nza = a%get_nzeros()
+    nzb = b%get_nzeros()
+    nzc = 2*(nza+nzb)
+    call c%allocate(ma,nb,nzc)
+
+    call csr_spspmm(a,b,c,info)
+  case (spspmm_omp_gustavson)
+    call spmm_omp_gustavson(a,b,c,info)
+  case (spspmm_omp_gustavson_1d)
+    call spmm_omp_gustavson_1d(a,b,c,info)
+  case (spspmm_serial_rb_tree)
+    call spmm_serial_rb_tree(a,b,c,info)
+  case (spspmm_omp_rb_tree)
+    call spmm_omp_rb_tree(a,b,c,info)
+  case (spspmm_omp_two_pass)
+    call spmm_omp_two_pass(a,b,c,info)
+  case default
+    write(psb_err_unit,*) 'Unknown spspmm implementation'
+    ! push error
+    goto 9999
+  end select
+
+  call c%set_asb()
+  call c%set_host()
+
+  call psb_erractionrestore(err_act)
+  return
+
+9999 call psb_error_handler(err_act)
+
+  return
+
+contains
+
+  subroutine csr_spspmm(a,b,c,info)
+    implicit none
+    type(psb_s_csr_sparse_mat), intent(in)  :: a,b
+    type(psb_s_csr_sparse_mat), intent(inout) :: c
+    integer(psb_ipk_), intent(out)          :: info
+    integer(psb_ipk_)              :: ma,na,mb,nb
+    integer(psb_ipk_), allocatable :: irow(:), idxs(:)
+    real(psb_spk_), allocatable    :: row(:)
+    integer(psb_ipk_)              :: i,j,k,irw,icl,icf, iret, &
+         & nzc,nnzre, isz, ipb, irwsz, nrc, nze
+    real(psb_spk_)                 :: cfb
+
+
+    info = psb_success_
+    ma = a%get_nrows()
+    na = a%get_ncols()
+    mb = b%get_nrows()
+    nb = b%get_ncols()
 
+    nze = min(size(c%val),size(c%ja))
+    isz = max(ma,na,mb,nb)
+    call psb_realloc(isz,row,info)
+    if (info == 0) call psb_realloc(isz,idxs,info)
+    if (info == 0) call psb_realloc(isz,irow,info)
+    if (info /= 0) return
+    row  = dzero
+    irow = 0
+    nzc  = 1
+    do j = 1,ma
+      c%irp(j) = nzc
+      nrc = 0
+      do k = a%irp(j), a%irp(j+1)-1
+        irw = a%ja(k)
+        cfb = a%val(k)
+        irwsz = b%irp(irw+1)-b%irp(irw)
+        do i = b%irp(irw),b%irp(irw+1)-1
+          icl = b%ja(i)
+          if (irow(icl)<j) then
+            nrc = nrc + 1
+            idxs(nrc) = icl
+            irow(icl) = j
+          end if
+          row(icl)  = row(icl)  + cfb*b%val(i)
+        end do
+      end do
+      if (nrc > 0 ) then
+        if ((nzc+nrc)>nze) then
+          nze = max(ma*((nzc+j-1)/j),nzc+2*nrc)
+          call psb_realloc(nze,c%val,info)
+          if (info == 0) call psb_realloc(nze,c%ja,info)
+          if (info /= 0) return
+        end if
+
+        call psb_qsort(idxs(1:nrc))
+        do i=1, nrc
+          irw        = idxs(i)
+          c%ja(nzc)  = irw
+          c%val(nzc) = row(irw)
+          row(irw)   = dzero
+          nzc        = nzc + 1
+        end do
+      end if
+    end do
+
+    c%irp(ma+1) = nzc
+  end subroutine csr_spspmm
+
+  ! gustavson's algorithm using perfect hashing 
+  ! and OpenMP parallelisation
+  subroutine spmm_omp_gustavson(a,b,c,info)
+    use omp_lib
+
+    implicit none
+    type(psb_s_csr_sparse_mat), intent(in) :: a,b
+    type(psb_s_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    real(psb_spk_), allocatable :: vals(:), acc(:)
+    integer(psb_ipk_)   :: ma, nb
+    integer(psb_ipk_), allocatable :: col_inds(:), offsets(:)
+    integer(psb_ipk_)   :: irw, jj, j, k, nnz, rwnz, thread_upperbound, start_idx, end_idx
+
+    ma = a%get_nrows()
+    nb = b%get_ncols()
+
+    call c%allocate(ma, nb)
+    c%irp(1) = 1
+
+    ! dense accumulator
+    ! https://sc18.supercomputing.org/proceedings/workshops/workshop_files/ws_lasalss115s2-file1.pdf
+    call psb_realloc(nb, acc, info)
+
+    allocate(offsets(omp_get_max_threads()))
+    !$omp parallel private(vals,col_inds,nnz,rwnz,thread_upperbound,acc,start_idx,end_idx) &
+    !$omp shared(a,b,c,offsets) 
+    thread_upperbound = 0
+    start_idx = 0
+    !$omp do schedule(static) private(irw, jj, j)
+    do irw = 1, ma
+      if (start_idx == 0) then
+        start_idx = irw
+      end if
+      end_idx = irw
+      do jj = a%irp(irw), a%irp(irw + 1) - 1
+        j = a%ja(jj)
+        thread_upperbound = thread_upperbound + b%irp(j+1) - b%irp(j)
+      end do
+    end do
+    !$omp end do
+
+    call psb_realloc(thread_upperbound, vals, info)
+    call psb_realloc(thread_upperbound, col_inds, info)
+
+    ! possible bottleneck
+    acc = 0
+
+    nnz = 0
+    !$omp do schedule(static) private(irw, jj, j, k)
+    do irw = 1, ma
+      rwnz = 0
+      do jj = a%irp(irw), a%irp(irw + 1) - 1
+        j = a%ja(jj)
+        do k = b%irp(j), b%irp(j + 1) - 1
+          if (acc(b%ja(k)) == 0) then
+            nnz = nnz + 1
+            rwnz = rwnz + 1
+            col_inds(nnz) =  b%ja(k)
+          end if
+          acc(b%ja(k)) = acc(b%ja(k)) + a%val(jj) * b%val(k) 
+        end do
+      end do
+      call psb_qsort(col_inds(nnz - rwnz + 1:nnz))
+
+      do k = nnz - rwnz + 1, nnz
+        vals(k) = acc(col_inds(k))
+        acc(col_inds(k)) = 0
+      end do
+      c%irp(irw + 1) = rwnz
+    end do
+    !$omp end do
+
+    offsets(omp_get_thread_num() + 1) = nnz
+    !$omp barrier
+
+    ! possible bottleneck
+    !$omp single
+    do k = 1, omp_get_num_threads() - 1
+      offsets(k + 1) = offsets(k + 1) + offsets(k)
+    end do
+    !$omp end single
+
+    !$omp barrier
+
+    if (omp_get_thread_num() /= 0) then
+      c%irp(start_idx) = offsets(omp_get_thread_num()) + 1
+    end if
+
+    do irw = start_idx, end_idx - 1
+      c%irp(irw + 1) = c%irp(irw + 1) + c%irp(irw)
+    end do
+
+    !$omp barrier
+
+    !$omp single
+    c%irp(ma + 1) = c%irp(ma + 1) + c%irp(ma)
+    call psb_realloc(c%irp(ma + 1), c%val, info)        
+    call psb_realloc(c%irp(ma + 1), c%ja, info)
+    !$omp end single
+
+    c%val(c%irp(start_idx):c%irp(end_idx + 1) - 1) = vals(1:nnz)
+    c%ja(c%irp(start_idx):c%irp(end_idx + 1) - 1) = col_inds(1:nnz)
+    !$omp end parallel
+  end subroutine spmm_omp_gustavson
+
+  subroutine spmm_omp_gustavson_1d(a,b,c,info)
+    use omp_lib
+
+    implicit none
+    type(psb_s_csr_sparse_mat), intent(in) :: a,b
+    type(psb_s_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    real(psb_spk_), allocatable :: vals(:), acc(:)
+    integer(psb_ipk_)   :: ma, nb
+    integer(psb_ipk_), allocatable :: col_inds(:), offsets(:)
+    integer(psb_ipk_)   :: irw, jj, j, k, nnz, rwnz, thread_upperbound, &
+         start_idx, end_idx , blk, blk_size, rwstart,&
+         rwblk, rwblkrem, nblks
+
+    ma = a%get_nrows()
+    nb = b%get_ncols()
+
+    call c%allocate(ma, nb)
+    c%irp(1) = 1
+
+    ! dense accumulator
+    ! https://sc18.supercomputing.org/proceedings/workshops/workshop_files/ws_lasalss115s2-file1.pdf
+    call psb_realloc(nb, acc, info)
+    allocate(offsets(omp_get_max_threads()))
+
+    nblks = 4 * omp_get_max_threads()
+    rwblk = (ma / nblks)
+    rwblkrem = modulo(ma, nblks)
+    !$omp parallel private(vals,col_inds,nnz,thread_upperbound,acc,start_idx,end_idx) shared(a,b,c,offsets)
+    thread_upperbound = 0
+    start_idx = 0
+    !$omp do schedule(static) private(irw, jj, j)
+    do irw = 1, ma
+      do jj = a%irp(irw), a%irp(irw + 1) - 1
+        j = a%ja(jj)
+        thread_upperbound = thread_upperbound + b%irp(j+1) - b%irp(j)
+      end do
+    end do
+    !$omp end do
+
+    call psb_realloc(thread_upperbound, vals, info)
+    call psb_realloc(thread_upperbound, col_inds, info)
+
+    ! possible bottleneck
+    acc = 0
+
+    nnz = 0
+    !$omp do schedule(static) private(irw,jj,j,k,rwnz,blk,blk_size,rwstart)
+    do blk = 0, nblks - 1
+      if (blk < rwblkrem) then
+        blk_size = rwblk + 1
+        rwstart = blk * rwblk + blk + 1
+      else
+        blk_size = rwblk
+        rwstart = blk * rwblk &
+             + rwblkrem + 1
+      end if
+      do irw = rwstart, rwstart + blk_size - 1
+        if (start_idx == 0) then
+          start_idx = irw
+        end if
+        end_idx = irw
+        rwnz = 0
+        do jj = a%irp(irw), a%irp(irw + 1) - 1
+          j = a%ja(jj)
+          do k = b%irp(j), b%irp(j + 1) - 1
+            if (acc(b%ja(k)) == 0) then
+              nnz = nnz + 1
+              rwnz = rwnz + 1
+              col_inds(nnz) =  b%ja(k)
+            end if
+            acc(b%ja(k)) = acc(b%ja(k)) + a%val(jj) * b%val(k) 
+          end do
+        end do
+        call psb_qsort(col_inds(nnz - rwnz + 1:nnz))
+
+        do k = nnz - rwnz + 1, nnz
+          vals(k) = acc(col_inds(k))
+          acc(col_inds(k)) = 0
+        end do
+        c%irp(irw + 1) = rwnz
+      end do
+    end do
+    !$omp end do
+
+    offsets(omp_get_thread_num() + 1) = nnz
+    !$omp barrier
+
+    ! possible bottleneck
+    !$omp single
+    do k = 1, omp_get_num_threads() - 1
+      offsets(k + 1) = offsets(k + 1) + offsets(k)
+    end do
+    !$omp end single
+
+    !$omp barrier
+
+    if (omp_get_thread_num() /= 0) then
+      c%irp(start_idx) = offsets(omp_get_thread_num()) + 1
+    end if
+
+    do irw = start_idx, end_idx - 1
+      c%irp(irw + 1) = c%irp(irw + 1) + c%irp(irw)
+    end do
+
+    !$omp barrier
+
+    !$omp single
+    c%irp(ma + 1) = c%irp(ma + 1) + c%irp(ma)
+    call psb_realloc(c%irp(ma + 1), c%val, info)        
+    call psb_realloc(c%irp(ma + 1), c%ja, info)
+    !$omp end single
+
+    c%val(c%irp(start_idx):c%irp(end_idx + 1) - 1) = vals(1:nnz)
+    c%ja(c%irp(start_idx):c%irp(end_idx + 1) - 1) = col_inds(1:nnz)
+    !$omp end parallel
+  end subroutine spmm_omp_gustavson_1d
+
+  subroutine spmm_serial_rb_tree(a,b,c,info)
+    use psb_rb_idx_tree_mod
+    implicit none
+    type(psb_s_csr_sparse_mat), intent(in) :: a,b
+    type(psb_s_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    integer(psb_ipk_)   :: a_m, b_n
+    integer(psb_ipk_)   :: row, col
+    type(psb_s_rb_idx_tree), allocatable :: row_accs(:)
+
+    a_m = a%get_nrows()
+    b_n = b%get_ncols()
+
+    allocate(row_accs(a_m))
+    call c%allocate(a_m, b_n)
+
+    do row = 1, a_m
+      row_accs(row)%nnz = 0
+      nullify(row_accs(row)%root)
+      do col = a%irp(row), a%irp(row + 1) - 1
+        call psb_rb_idx_tree_scalar_sparse_row_mul(row_accs(row), a%val(col), b, a%ja(col))
+      end do
+    end do
+    call psb_rb_idx_tree_merge(row_accs, c)
+
+    deallocate(row_accs)
+
+    info = 0
+  end subroutine spmm_serial_rb_tree
+
+  subroutine spmm_omp_rb_tree(a,b,c,info)
+    use omp_lib
+    use psb_rb_idx_tree_mod
+    implicit none
+    type(psb_s_csr_sparse_mat), intent(in) :: a,b
+    type(psb_s_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    integer(psb_ipk_)   :: a_m, b_n
+    integer(psb_ipk_)   :: row, col
+    type(psb_s_rb_idx_tree), allocatable :: row_accs(:)
+    real(8) :: tic, toc
+
+    a_m = a%get_nrows()
+    b_n = b%get_ncols()
+
+    call c%allocate(a_m, b_n)
+
+    allocate(row_accs(a_m))
+    call c%allocate(a_m, b_n)
+
+    !$omp parallel do schedule(static)
+    do row = 1, a_m
+      row_accs(row)%nnz = 0
+      nullify(row_accs(row)%root)
+      do col = a%irp(row), a%irp(row + 1) - 1
+        call psb_rb_idx_tree_scalar_sparse_row_mul(row_accs(row), a%val(col), b, a%ja(col))
+      end do
+    end do
+    !$omp end parallel do
+
+    call psb_rb_idx_tree_merge(row_accs, c)
+
+    deallocate(row_accs)
+    info = 0
+  end subroutine spmm_omp_rb_tree
+
+  subroutine compute_indices(a, b, c, info)
+    implicit none
+    type(psb_s_csr_sparse_mat), intent(in) :: a,b
+    type(psb_s_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    integer :: full_mat_bound
+    integer :: row, col, i, j, k, nnz
+
+    full_mat_bound = 0
+    !omp parallel do schedule(static) reduction(+:full_mat_bound)
+    do row = 1, a%get_nrows()
+      do col = a%irp(row), a%irp(row + 1) - 1
+        j = a%ja(col)
+        full_mat_bound = full_mat_bound + b%irp(j+1) - b%irp(j)
+      end do
+    end do
+    !omp end parallel do
+
+    call psb_realloc(a%get_nrows() + 1, c%irp, info)
+    call psb_realloc(full_mat_bound, c%ja, info)
+    c%ja = 0
+    c%irp(1) = 1
+
+    nnz = 0
+
+    do row = 1, a%get_nrows()
+      do col = a%irp(row), a%irp(row + 1) - 1
+        do i = b%irp(a%ja(col)), b%irp(a%ja(col) + 1) - 1
+          k = 0
+          do while(c%ja(c%irp(row) + k) /= 0 .and. c%ja(c%irp(row) + k) /= b%ja(i))
+            k = k + 1
+          end do
+          if (c%ja(c%irp(row) + k) == 0) then
+            c%ja(c%irp(row)+k) = b%ja(i)
+            nnz = nnz + 1
+          end if
+        end do
+      end do
+      c%irp(row + 1) = nnz + 1
+      call psb_qsort(c%ja(c%irp(row):c%irp(row + 1)-1))
+    end do
+
+
+    call psb_realloc(nnz, c%ja, info)
+    call psb_realloc(nnz, c%val, info)
+
+    c%val = 0
+  end subroutine compute_indices
+
+  subroutine direct_scalar_sparse_row_mul(out_mat, out_row_num, scalar, mat, trgt_row_num)
+    type(psb_s_csr_sparse_mat), intent(inout) :: out_mat
+    integer(psb_ipk_), intent(in) :: out_row_num
+    real(psb_spk_), intent(in) :: scalar
+    type(psb_s_csr_sparse_mat), intent(in) :: mat
+    integer(psb_ipk_), intent(in) :: trgt_row_num
+
+    integer(psb_ipk_) :: i, k, row_start, row_end
+
+    row_start = out_mat%irp(out_row_num)
+    row_end = out_mat%irp(out_row_num + 1) - 1
+
+    do i = mat%irp(trgt_row_num), mat%irp(trgt_row_num + 1) - 1
+      do k = out_mat%irp(out_row_num), out_mat%irp(out_row_num + 1) - 1
+        if (out_mat%ja(k) == mat%ja(i)) then
+          out_mat%val(k) = out_mat%val(k) + scalar * mat%val(i)
+          exit
+        end if
+      end do
+    end do
+
+  end subroutine direct_scalar_sparse_row_mul
+
+  subroutine spmm_omp_two_pass(a,b,c,info)
+    use omp_lib
+
+    implicit none
+    type(psb_s_csr_sparse_mat), intent(in) :: a,b
+    type(psb_s_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    integer(psb_ipk_)   :: a_m, b_n, row, col
+
+    a_m = a%get_nrows()
+    b_n = b%get_ncols()
+
+    call c%allocate(a_m, b_n)
+
+    call compute_indices(a, b, c, info)
+
+    !$omp parallel do schedule(static)
+    do row = 1, a_m
+      do col = a%irp(row), a%irp(row + 1) - 1
+        call direct_scalar_sparse_row_mul(c, row, a%val(col), b, a%ja(col))
+      end do
+    end do
+    !$omp end parallel do
+  end subroutine spmm_omp_two_pass
+
+end subroutine psb_scsrspspmm
+#endif
 
 !
 !

base/serial/impl/psb_s_rb_idx_tree_impl.F90

@@ -0,0 +1,329 @@
+!
+!                Parallel Sparse BLAS  version 3.5
+!      (C) Copyright 2006-2018
+!        Salvatore Filippone
+!        Alfredo Buttari
+!
+!    Redistribution and use in source and binary forms, with or without
+!    modification, are permitted provided that the following conditions
+!    are met:
+!      1. Redistributions of source code must retain the above copyright
+!         notice, this list of conditions and the following disclaimer.
+!      2. Redistributions in binary form must reproduce the above copyright
+!         notice, this list of conditions, and the following disclaimer in the
+!         documentation and/or other materials provided with the distribution.
+!      3. The name of the PSBLAS group or the names of its contributors may
+!         not be used to endorse or promote products derived from this
+!         software without specific written permission.
+!
+!    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+!    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+!    TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+!    PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE PSBLAS GROUP OR ITS CONTRIBUTORS
+!    BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+!    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+!    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+!    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+!    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+!    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+!    POSSIBILITY OF SUCH DAMAGE.
+!
+!
+!
+! package: psb_s_rb_idx_tree_impl
+! 
+! Red black tree implementation ordered by index
+!
+! Each node contains and index and a double precision value
+!
+! The tree should always be well balanced
+!
+! inserting a node with an existing index will 
+! add up the new value to the old one
+! Contributed by Dimitri Walther
+! 
+subroutine psb_s_rb_idx_tree_insert(this, idx, val)
+  use psb_s_rb_idx_tree_mod, psb_protect_name => psb_s_rb_idx_tree_insert
+  implicit none
+  class(psb_s_rb_idx_tree), intent(inout) :: this
+  integer(psb_ipk_), intent(in) :: idx
+  real(psb_spk_), intent(in) :: val
+
+  character(len=22) :: name
+  type(psb_s_rb_idx_node), pointer :: new_node
+  type(psb_s_rb_idx_node), pointer :: current, previous
+  name='psb_rb_idx_tree_insert'
+
+  allocate(new_node)
+  new_node%idx = idx
+  new_node%val = val
+  nullify(new_node%left)
+  nullify(new_node%right)
+  nullify(new_node%parent)
+  new_node%is_red = .true.
+
+
+  if (.not. associated(this%root)) then
+    this%root => new_node
+    this%nnz = 1
+    new_node%is_red = .false.
+    return
+  end if
+
+  current => this%root
+
+  do while (associated(current))
+    previous => current
+
+    if (idx == current%idx) then
+      current%val = current%val + val
+      deallocate(new_node)
+      return
+    else if (idx < current%idx) then
+      current => current%left
+    else
+
+      current => current%right
+    end if
+  end do
+
+  if (idx < previous%idx) then
+    new_node%parent => previous
+    previous%left => new_node
+  else
+    new_node%parent => previous
+    previous%right => new_node
+  end if
+
+  call psb_s_rb_idx_tree_fix_insertion(this, new_node)
+
+  this%nnz = this%nnz + 1
+end subroutine psb_s_rb_idx_tree_insert
+
+subroutine psb_s_rb_idx_tree_fix_insertion(this, node)
+  use psb_s_rb_idx_tree_mod, psb_protect_name => psb_s_rb_idx_tree_fix_insertion
+  implicit none
+  class(psb_s_rb_idx_tree), intent(inout) :: this
+  type(psb_s_rb_idx_node), pointer, intent(inout) :: node
+
+  character(len=29) :: name
+  type(psb_s_rb_idx_node), pointer :: current, parent, grand_parent, uncle
+  name = 'psb_rb_idx_tree_fix_insertion'
+
+  current => node
+  parent => current%parent
+  do while(associated(parent) .and. parent%is_red)
+    ! grand parent exist because root can't be red
+    grand_parent => parent%parent
+    if (parent%idx < grand_parent%idx) then
+      uncle => grand_parent%right
+    else
+      uncle => grand_parent%left
+    end if
+
+    if (associated(uncle) .and. uncle%is_red) then
+      parent%is_red = .false.
+      uncle%is_red = .false.
+      grand_parent%is_red = .true.
+      current => grand_parent
+      parent => current%parent
+
+      ! Left-Left case
+    else if (current%idx < parent%idx .and. &
+         parent%idx < grand_parent%idx) then
+      call psb_s_rb_idx_tree_rotate_right(grand_parent)
+      call psb_s_rb_idx_tree_swap_colors(parent, grand_parent)
+
+      if (this%root%idx == grand_parent%idx) this%root => parent
+
+      return
+      ! Left-Right case
+    else if (current%idx > parent%idx .and. &
+         parent%idx < grand_parent%idx) then
+      call psb_s_rb_idx_tree_rotate_left(parent)
+      call psb_s_rb_idx_tree_rotate_right(grand_parent)
+      call psb_s_rb_idx_tree_swap_colors(current, grand_parent)
+
+      if (this%root%idx == grand_parent%idx) this%root => current
+
+      return
+      ! Right-Right case
+    else if (current%idx > parent%idx .and. &
+         parent%idx > grand_parent%idx) then
+      call psb_s_rb_idx_tree_rotate_left(grand_parent)
+      call psb_s_rb_idx_tree_swap_colors(parent, grand_parent)
+
+      if (this%root%idx == grand_parent%idx) this%root => parent
+
+      return
+      ! Right-Left case
+    else
+      call psb_s_rb_idx_tree_rotate_right(parent)
+      call psb_s_rb_idx_tree_rotate_left(grand_parent)
+      call psb_s_rb_idx_tree_swap_colors(current, grand_parent)
+
+      if (this%root%idx == grand_parent%idx) this%root => current
+
+      return
+    end if
+  end do
+
+  this%root%is_red = .false.
+end subroutine psb_s_rb_idx_tree_fix_insertion
+
+subroutine psb_s_rb_idx_tree_swap_colors(n1, n2)
+  use psb_s_rb_idx_tree_mod, psb_protect_name => psb_s_rb_idx_tree_swap_colors
+  implicit none
+  type(psb_s_rb_idx_node), pointer, intent(inout) :: n1, n2
+
+  character(len=27) :: name
+  logical :: tmp
+  name='psb_rb_idx_tree_swap_colors'
+
+  tmp = n1%is_red
+  n1%is_red = n2%is_red
+  n2%is_red = tmp
+end subroutine psb_s_rb_idx_tree_swap_colors
+
+subroutine psb_s_rb_idx_tree_rotate_right(node)
+  use psb_s_rb_idx_tree_mod, psb_protect_name => psb_s_rb_idx_tree_rotate_right
+  implicit none
+  type(psb_s_rb_idx_node), pointer, intent(inout) :: node
+
+  character(len=28) :: name
+  type(psb_s_rb_idx_node), pointer :: l, lr
+  name='psb_rb_idx_tree_rotate_right'
+
+  if (.not. associated(node%left)) return
+
+  l => node%left
+  lr => l%right
+  node%left => lr
+
+  if (associated(lr)) lr%parent => node
+
+  if (associated(node%parent)) then
+    if (node%idx < node%parent%idx) then
+      node%parent%left => l
+    else
+      node%parent%right => l
+    end if
+  end if
+
+  l%parent => node%parent
+  node%parent => l
+
+  l%right => node
+end subroutine psb_s_rb_idx_tree_rotate_right
+
+subroutine psb_s_rb_idx_tree_rotate_left(node)
+  use psb_s_rb_idx_tree_mod, psb_protect_name => psb_s_rb_idx_tree_rotate_left
+  implicit none
+  type(psb_s_rb_idx_node), pointer, intent(inout) :: node
+
+  character(len=27) :: name
+  type(psb_s_rb_idx_node), pointer :: r, rl
+  name='psb_rb_idx_tree_rotate_left'
+
+  if (.not. associated(node%right)) return
+
+  r => node%right
+  rl => r%left
+  node%right => rl
+
+  if (associated(rl)) rl%parent => node
+
+  if (associated(node%parent)) then
+    if (node%idx < node%parent%idx) then
+      node%parent%left => r
+    else
+      node%parent%right => r
+    end if
+  end if
+
+  r%parent => node%parent
+  node%parent => r
+
+  r%left => node
+end subroutine psb_s_rb_idx_tree_rotate_left
+
+subroutine psb_s_rb_idx_tree_scalar_sparse_row_mul(tree, scalar, mat, row_num)
+  use psb_s_rb_idx_tree_mod, psb_protect_name => psb_s_rb_idx_tree_scalar_sparse_row_mul
+  use psb_s_csr_mat_mod, only : psb_s_csr_sparse_mat
+  implicit none
+  type(psb_s_rb_idx_tree), intent(inout) :: tree
+  real(psb_spk_), intent(in) :: scalar
+  type(psb_s_csr_sparse_mat), intent(in) :: mat
+  integer(psb_ipk_), intent(in) :: row_num
+
+  character(len=37) :: name
+  integer(psb_ipk_) :: i
+  name='psb_rb_idx_tree_scalar_sparse_row_mul'
+
+  do i = mat%irp(row_num), mat%irp(row_num + 1) - 1
+    call tree%insert(mat%ja(i),scalar * mat%val(i))
+  end do
+
+end subroutine psb_s_rb_idx_tree_scalar_sparse_row_mul
+
+subroutine psb_s_rb_idx_tree_merge(trees, mat)
+#if defined(OPENMP)
+  use omp_lib
+#endif
+  use psb_realloc_mod
+  use psb_s_rb_idx_tree_mod, psb_protect_name => psb_s_rb_idx_tree_merge
+  use psb_s_csr_mat_mod, only : psb_s_csr_sparse_mat
+  implicit none
+  type(psb_s_rb_idx_tree), allocatable, intent(inout) :: trees(:)
+  type(psb_s_csr_sparse_mat), intent(inout) :: mat
+
+  character(len=21) :: name
+  integer(psb_ipk_) :: i, j, rows, info, nnz
+  type(psb_s_rb_idx_node), pointer :: current, previous
+  name='psb_rb_idx_tree_merge'
+
+  rows = size(trees)
+
+  mat%irp(1) = 1
+
+  do i=1, rows
+    mat%irp(i + 1) = mat%irp(i) + trees(i)%nnz
+  end do
+
+  nnz = mat%irp(rows + 1)
+  call psb_realloc(nnz, mat%val, info)
+  call psb_realloc(nnz, mat%ja, info)
+
+#if defined(OPENMP)
+  !$omp parallel do schedule(static), private(current, previous, j)
+#endif
+  do i = 1, size(trees)
+    j = 0
+    current => trees(i)%root
+    do while(associated(current))
+      ! go to the left-most node
+      do while(associated(current%left))
+        current => current%left
+      end do
+      mat%val(j + mat%irp(i)) = current%val
+      mat%ja(j + mat%irp(i)) = current%idx
+      j = j + 1
+
+      previous => current
+      if (associated(current%right)) then
+        if (associated(current%parent)) then
+          current%parent%left => current%right
+        end if
+        current%right%parent => current%parent
+        current => current%right
+      else
+        current => current%parent
+        if (associated(current)) nullify(current%left)
+      end if
+      deallocate(previous)
+    end do
+  end do
+#if defined(OPENMP)
+  !$omp end parallel do
+#endif
+end subroutine psb_s_rb_idx_tree_merge

base/serial/impl/psb_z_csr_impl.F90

@@ -3654,6 +3654,7 @@ subroutine  psb_z_csr_clean_zeros(a, info)
   call a%set_host()
 end subroutine psb_z_csr_clean_zeros
 
+#if 0
 subroutine psb_zcsrspspmm(a,b,c,info)
   use psb_z_mat_mod
   use psb_serial_mod, psb_protect_name => psb_zcsrspspmm
@@ -3776,7 +3777,538 @@ contains
   end subroutine csr_spspmm
 
 end subroutine psb_zcsrspspmm
+#else
+subroutine psb_zcsrspspmm(a,b,c,info)
+  use psb_z_mat_mod
+  use psb_serial_mod, psb_protect_name => psb_zcsrspspmm
+
+  implicit none
+
+  class(psb_z_csr_sparse_mat), intent(in) :: a,b
+  type(psb_z_csr_sparse_mat), intent(out)  :: c
+  integer(psb_ipk_), intent(out)                     :: info
+  integer(psb_ipk_) :: ma,na,mb,nb, nzc, nza, nzb
+  character(len=20) :: name
+  integer(psb_ipk_) :: err_act
+  name='psb_csrspspmm'
+  call psb_erractionsave(err_act)
+  info = psb_success_
+
+  if (a%is_dev())   call a%sync()
+  if (b%is_dev())   call b%sync()
+
+  ma = a%get_nrows()
+  na = a%get_ncols()
+  mb = b%get_nrows()
+  nb = b%get_ncols()
+
+
+  if ( mb /= na ) then
+    write(psb_err_unit,*) 'Mismatch in SPSPMM: ',ma,na,mb,nb
+    info = psb_err_invalid_matrix_sizes_
+    call psb_errpush(info,name)
+    goto 9999
+  endif
+
+  select case(spspmm_impl)
+  case (spspmm_serial)
+    ! Estimate number of nonzeros on output.
+    nza = a%get_nzeros()
+    nzb = b%get_nzeros()
+    nzc = 2*(nza+nzb)
+    call c%allocate(ma,nb,nzc)
+
+    call csr_spspmm(a,b,c,info)
+  case (spspmm_omp_gustavson)
+    call spmm_omp_gustavson(a,b,c,info)
+  case (spspmm_omp_gustavson_1d)
+    call spmm_omp_gustavson_1d(a,b,c,info)
+  case (spspmm_serial_rb_tree)
+    call spmm_serial_rb_tree(a,b,c,info)
+  case (spspmm_omp_rb_tree)
+    call spmm_omp_rb_tree(a,b,c,info)
+  case (spspmm_omp_two_pass)
+    call spmm_omp_two_pass(a,b,c,info)
+  case default
+    write(psb_err_unit,*) 'Unknown spspmm implementation'
+    ! push error
+    goto 9999
+  end select
+
+  call c%set_asb()
+  call c%set_host()
+
+  call psb_erractionrestore(err_act)
+  return
+
+9999 call psb_error_handler(err_act)
+
+  return
+
+contains
+
+  subroutine csr_spspmm(a,b,c,info)
+    implicit none
+    type(psb_z_csr_sparse_mat), intent(in)  :: a,b
+    type(psb_z_csr_sparse_mat), intent(inout) :: c
+    integer(psb_ipk_), intent(out)          :: info
+    integer(psb_ipk_)              :: ma,na,mb,nb
+    integer(psb_ipk_), allocatable :: irow(:), idxs(:)
+    complex(psb_dpk_), allocatable    :: row(:)
+    integer(psb_ipk_)              :: i,j,k,irw,icl,icf, iret, &
+         & nzc,nnzre, isz, ipb, irwsz, nrc, nze
+    complex(psb_dpk_)                 :: cfb
+
+
+    info = psb_success_
+    ma = a%get_nrows()
+    na = a%get_ncols()
+    mb = b%get_nrows()
+    nb = b%get_ncols()
 
+    nze = min(size(c%val),size(c%ja))
+    isz = max(ma,na,mb,nb)
+    call psb_realloc(isz,row,info)
+    if (info == 0) call psb_realloc(isz,idxs,info)
+    if (info == 0) call psb_realloc(isz,irow,info)
+    if (info /= 0) return
+    row  = dzero
+    irow = 0
+    nzc  = 1
+    do j = 1,ma
+      c%irp(j) = nzc
+      nrc = 0
+      do k = a%irp(j), a%irp(j+1)-1
+        irw = a%ja(k)
+        cfb = a%val(k)
+        irwsz = b%irp(irw+1)-b%irp(irw)
+        do i = b%irp(irw),b%irp(irw+1)-1
+          icl = b%ja(i)
+          if (irow(icl)<j) then
+            nrc = nrc + 1
+            idxs(nrc) = icl
+            irow(icl) = j
+          end if
+          row(icl)  = row(icl)  + cfb*b%val(i)
+        end do
+      end do
+      if (nrc > 0 ) then
+        if ((nzc+nrc)>nze) then
+          nze = max(ma*((nzc+j-1)/j),nzc+2*nrc)
+          call psb_realloc(nze,c%val,info)
+          if (info == 0) call psb_realloc(nze,c%ja,info)
+          if (info /= 0) return
+        end if
+
+        call psb_qsort(idxs(1:nrc))
+        do i=1, nrc
+          irw        = idxs(i)
+          c%ja(nzc)  = irw
+          c%val(nzc) = row(irw)
+          row(irw)   = dzero
+          nzc        = nzc + 1
+        end do
+      end if
+    end do
+
+    c%irp(ma+1) = nzc
+  end subroutine csr_spspmm
+
+  ! gustavson's algorithm using perfect hashing 
+  ! and OpenMP parallelisation
+  subroutine spmm_omp_gustavson(a,b,c,info)
+    use omp_lib
+
+    implicit none
+    type(psb_z_csr_sparse_mat), intent(in) :: a,b
+    type(psb_z_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    complex(psb_dpk_), allocatable :: vals(:), acc(:)
+    integer(psb_ipk_)   :: ma, nb
+    integer(psb_ipk_), allocatable :: col_inds(:), offsets(:)
+    integer(psb_ipk_)   :: irw, jj, j, k, nnz, rwnz, thread_upperbound, start_idx, end_idx
+
+    ma = a%get_nrows()
+    nb = b%get_ncols()
+
+    call c%allocate(ma, nb)
+    c%irp(1) = 1
+
+    ! dense accumulator
+    ! https://sc18.supercomputing.org/proceedings/workshops/workshop_files/ws_lasalss115s2-file1.pdf
+    call psb_realloc(nb, acc, info)
+
+    allocate(offsets(omp_get_max_threads()))
+    !$omp parallel private(vals,col_inds,nnz,rwnz,thread_upperbound,acc,start_idx,end_idx) &
+    !$omp shared(a,b,c,offsets) 
+    thread_upperbound = 0
+    start_idx = 0
+    !$omp do schedule(static) private(irw, jj, j)
+    do irw = 1, ma
+      if (start_idx == 0) then
+        start_idx = irw
+      end if
+      end_idx = irw
+      do jj = a%irp(irw), a%irp(irw + 1) - 1
+        j = a%ja(jj)
+        thread_upperbound = thread_upperbound + b%irp(j+1) - b%irp(j)
+      end do
+    end do
+    !$omp end do
+
+    call psb_realloc(thread_upperbound, vals, info)
+    call psb_realloc(thread_upperbound, col_inds, info)
+
+    ! possible bottleneck
+    acc = 0
+
+    nnz = 0
+    !$omp do schedule(static) private(irw, jj, j, k)
+    do irw = 1, ma
+      rwnz = 0
+      do jj = a%irp(irw), a%irp(irw + 1) - 1
+        j = a%ja(jj)
+        do k = b%irp(j), b%irp(j + 1) - 1
+          if (acc(b%ja(k)) == 0) then
+            nnz = nnz + 1
+            rwnz = rwnz + 1
+            col_inds(nnz) =  b%ja(k)
+          end if
+          acc(b%ja(k)) = acc(b%ja(k)) + a%val(jj) * b%val(k) 
+        end do
+      end do
+      call psb_qsort(col_inds(nnz - rwnz + 1:nnz))
+
+      do k = nnz - rwnz + 1, nnz
+        vals(k) = acc(col_inds(k))
+        acc(col_inds(k)) = 0
+      end do
+      c%irp(irw + 1) = rwnz
+    end do
+    !$omp end do
+
+    offsets(omp_get_thread_num() + 1) = nnz
+    !$omp barrier
+
+    ! possible bottleneck
+    !$omp single
+    do k = 1, omp_get_num_threads() - 1
+      offsets(k + 1) = offsets(k + 1) + offsets(k)
+    end do
+    !$omp end single
+
+    !$omp barrier
+
+    if (omp_get_thread_num() /= 0) then
+      c%irp(start_idx) = offsets(omp_get_thread_num()) + 1
+    end if
+
+    do irw = start_idx, end_idx - 1
+      c%irp(irw + 1) = c%irp(irw + 1) + c%irp(irw)
+    end do
+
+    !$omp barrier
+
+    !$omp single
+    c%irp(ma + 1) = c%irp(ma + 1) + c%irp(ma)
+    call psb_realloc(c%irp(ma + 1), c%val, info)        
+    call psb_realloc(c%irp(ma + 1), c%ja, info)
+    !$omp end single
+
+    c%val(c%irp(start_idx):c%irp(end_idx + 1) - 1) = vals(1:nnz)
+    c%ja(c%irp(start_idx):c%irp(end_idx + 1) - 1) = col_inds(1:nnz)
+    !$omp end parallel
+  end subroutine spmm_omp_gustavson
+
+  subroutine spmm_omp_gustavson_1d(a,b,c,info)
+    use omp_lib
+
+    implicit none
+    type(psb_z_csr_sparse_mat), intent(in) :: a,b
+    type(psb_z_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    complex(psb_dpk_), allocatable :: vals(:), acc(:)
+    integer(psb_ipk_)   :: ma, nb
+    integer(psb_ipk_), allocatable :: col_inds(:), offsets(:)
+    integer(psb_ipk_)   :: irw, jj, j, k, nnz, rwnz, thread_upperbound, &
+         start_idx, end_idx , blk, blk_size, rwstart,&
+         rwblk, rwblkrem, nblks
+
+    ma = a%get_nrows()
+    nb = b%get_ncols()
+
+    call c%allocate(ma, nb)
+    c%irp(1) = 1
+
+    ! dense accumulator
+    ! https://sc18.supercomputing.org/proceedings/workshops/workshop_files/ws_lasalss115s2-file1.pdf
+    call psb_realloc(nb, acc, info)
+    allocate(offsets(omp_get_max_threads()))
+
+    nblks = 4 * omp_get_max_threads()
+    rwblk = (ma / nblks)
+    rwblkrem = modulo(ma, nblks)
+    !$omp parallel private(vals,col_inds,nnz,thread_upperbound,acc,start_idx,end_idx) shared(a,b,c,offsets)
+    thread_upperbound = 0
+    start_idx = 0
+    !$omp do schedule(static) private(irw, jj, j)
+    do irw = 1, ma
+      do jj = a%irp(irw), a%irp(irw + 1) - 1
+        j = a%ja(jj)
+        thread_upperbound = thread_upperbound + b%irp(j+1) - b%irp(j)
+      end do
+    end do
+    !$omp end do
+
+    call psb_realloc(thread_upperbound, vals, info)
+    call psb_realloc(thread_upperbound, col_inds, info)
+
+    ! possible bottleneck
+    acc = 0
+
+    nnz = 0
+    !$omp do schedule(static) private(irw,jj,j,k,rwnz,blk,blk_size,rwstart)
+    do blk = 0, nblks - 1
+      if (blk < rwblkrem) then
+        blk_size = rwblk + 1
+        rwstart = blk * rwblk + blk + 1
+      else
+        blk_size = rwblk
+        rwstart = blk * rwblk &
+             + rwblkrem + 1
+      end if
+      do irw = rwstart, rwstart + blk_size - 1
+        if (start_idx == 0) then
+          start_idx = irw
+        end if
+        end_idx = irw
+        rwnz = 0
+        do jj = a%irp(irw), a%irp(irw + 1) - 1
+          j = a%ja(jj)
+          do k = b%irp(j), b%irp(j + 1) - 1
+            if (acc(b%ja(k)) == 0) then
+              nnz = nnz + 1
+              rwnz = rwnz + 1
+              col_inds(nnz) =  b%ja(k)
+            end if
+            acc(b%ja(k)) = acc(b%ja(k)) + a%val(jj) * b%val(k) 
+          end do
+        end do
+        call psb_qsort(col_inds(nnz - rwnz + 1:nnz))
+
+        do k = nnz - rwnz + 1, nnz
+          vals(k) = acc(col_inds(k))
+          acc(col_inds(k)) = 0
+        end do
+        c%irp(irw + 1) = rwnz
+      end do
+    end do
+    !$omp end do
+
+    offsets(omp_get_thread_num() + 1) = nnz
+    !$omp barrier
+
+    ! possible bottleneck
+    !$omp single
+    do k = 1, omp_get_num_threads() - 1
+      offsets(k + 1) = offsets(k + 1) + offsets(k)
+    end do
+    !$omp end single
+
+    !$omp barrier
+
+    if (omp_get_thread_num() /= 0) then
+      c%irp(start_idx) = offsets(omp_get_thread_num()) + 1
+    end if
+
+    do irw = start_idx, end_idx - 1
+      c%irp(irw + 1) = c%irp(irw + 1) + c%irp(irw)
+    end do
+
+    !$omp barrier
+
+    !$omp single
+    c%irp(ma + 1) = c%irp(ma + 1) + c%irp(ma)
+    call psb_realloc(c%irp(ma + 1), c%val, info)        
+    call psb_realloc(c%irp(ma + 1), c%ja, info)
+    !$omp end single
+
+    c%val(c%irp(start_idx):c%irp(end_idx + 1) - 1) = vals(1:nnz)
+    c%ja(c%irp(start_idx):c%irp(end_idx + 1) - 1) = col_inds(1:nnz)
+    !$omp end parallel
+  end subroutine spmm_omp_gustavson_1d
+
+  subroutine spmm_serial_rb_tree(a,b,c,info)
+    use psb_rb_idx_tree_mod
+    implicit none
+    type(psb_z_csr_sparse_mat), intent(in) :: a,b
+    type(psb_z_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    integer(psb_ipk_)   :: a_m, b_n
+    integer(psb_ipk_)   :: row, col
+    type(psb_z_rb_idx_tree), allocatable :: row_accs(:)
+
+    a_m = a%get_nrows()
+    b_n = b%get_ncols()
+
+    allocate(row_accs(a_m))
+    call c%allocate(a_m, b_n)
+
+    do row = 1, a_m
+      row_accs(row)%nnz = 0
+      nullify(row_accs(row)%root)
+      do col = a%irp(row), a%irp(row + 1) - 1
+        call psb_rb_idx_tree_scalar_sparse_row_mul(row_accs(row), a%val(col), b, a%ja(col))
+      end do
+    end do
+    call psb_rb_idx_tree_merge(row_accs, c)
+
+    deallocate(row_accs)
+
+    info = 0
+  end subroutine spmm_serial_rb_tree
+
+  subroutine spmm_omp_rb_tree(a,b,c,info)
+    use omp_lib
+    use psb_rb_idx_tree_mod
+    implicit none
+    type(psb_z_csr_sparse_mat), intent(in) :: a,b
+    type(psb_z_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    integer(psb_ipk_)   :: a_m, b_n
+    integer(psb_ipk_)   :: row, col
+    type(psb_z_rb_idx_tree), allocatable :: row_accs(:)
+    real(8) :: tic, toc
+
+    a_m = a%get_nrows()
+    b_n = b%get_ncols()
+
+    call c%allocate(a_m, b_n)
+
+    allocate(row_accs(a_m))
+    call c%allocate(a_m, b_n)
+
+    !$omp parallel do schedule(static)
+    do row = 1, a_m
+      row_accs(row)%nnz = 0
+      nullify(row_accs(row)%root)
+      do col = a%irp(row), a%irp(row + 1) - 1
+        call psb_rb_idx_tree_scalar_sparse_row_mul(row_accs(row), a%val(col), b, a%ja(col))
+      end do
+    end do
+    !$omp end parallel do
+
+    call psb_rb_idx_tree_merge(row_accs, c)
+
+    deallocate(row_accs)
+    info = 0
+  end subroutine spmm_omp_rb_tree
+
+  subroutine compute_indices(a, b, c, info)
+    implicit none
+    type(psb_z_csr_sparse_mat), intent(in) :: a,b
+    type(psb_z_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    integer :: full_mat_bound
+    integer :: row, col, i, j, k, nnz
+
+    full_mat_bound = 0
+    !omp parallel do schedule(static) reduction(+:full_mat_bound)
+    do row = 1, a%get_nrows()
+      do col = a%irp(row), a%irp(row + 1) - 1
+        j = a%ja(col)
+        full_mat_bound = full_mat_bound + b%irp(j+1) - b%irp(j)
+      end do
+    end do
+    !omp end parallel do
+
+    call psb_realloc(a%get_nrows() + 1, c%irp, info)
+    call psb_realloc(full_mat_bound, c%ja, info)
+    c%ja = 0
+    c%irp(1) = 1
+
+    nnz = 0
+
+    do row = 1, a%get_nrows()
+      do col = a%irp(row), a%irp(row + 1) - 1
+        do i = b%irp(a%ja(col)), b%irp(a%ja(col) + 1) - 1
+          k = 0
+          do while(c%ja(c%irp(row) + k) /= 0 .and. c%ja(c%irp(row) + k) /= b%ja(i))
+            k = k + 1
+          end do
+          if (c%ja(c%irp(row) + k) == 0) then
+            c%ja(c%irp(row)+k) = b%ja(i)
+            nnz = nnz + 1
+          end if
+        end do
+      end do
+      c%irp(row + 1) = nnz + 1
+      call psb_qsort(c%ja(c%irp(row):c%irp(row + 1)-1))
+    end do
+
+
+    call psb_realloc(nnz, c%ja, info)
+    call psb_realloc(nnz, c%val, info)
+
+    c%val = 0
+  end subroutine compute_indices
+
+  subroutine direct_scalar_sparse_row_mul(out_mat, out_row_num, scalar, mat, trgt_row_num)
+    type(psb_z_csr_sparse_mat), intent(inout) :: out_mat
+    integer(psb_ipk_), intent(in) :: out_row_num
+    complex(psb_dpk_), intent(in) :: scalar
+    type(psb_z_csr_sparse_mat), intent(in) :: mat
+    integer(psb_ipk_), intent(in) :: trgt_row_num
+
+    integer(psb_ipk_) :: i, k, row_start, row_end
+
+    row_start = out_mat%irp(out_row_num)
+    row_end = out_mat%irp(out_row_num + 1) - 1
+
+    do i = mat%irp(trgt_row_num), mat%irp(trgt_row_num + 1) - 1
+      do k = out_mat%irp(out_row_num), out_mat%irp(out_row_num + 1) - 1
+        if (out_mat%ja(k) == mat%ja(i)) then
+          out_mat%val(k) = out_mat%val(k) + scalar * mat%val(i)
+          exit
+        end if
+      end do
+    end do
+
+  end subroutine direct_scalar_sparse_row_mul
+
+  subroutine spmm_omp_two_pass(a,b,c,info)
+    use omp_lib
+
+    implicit none
+    type(psb_z_csr_sparse_mat), intent(in) :: a,b
+    type(psb_z_csr_sparse_mat), intent(out):: c
+    integer(psb_ipk_), intent(out) :: info
+
+    integer(psb_ipk_)   :: a_m, b_n, row, col
+
+    a_m = a%get_nrows()
+    b_n = b%get_ncols()
+
+    call c%allocate(a_m, b_n)
+
+    call compute_indices(a, b, c, info)
+
+    !$omp parallel do schedule(static)
+    do row = 1, a_m
+      do col = a%irp(row), a%irp(row + 1) - 1
+        call direct_scalar_sparse_row_mul(c, row, a%val(col), b, a%ja(col))
+      end do
+    end do
+    !$omp end parallel do
+  end subroutine spmm_omp_two_pass
+
+end subroutine psb_zcsrspspmm
+#endif
 
 !
 !

base/serial/impl/psb_z_rb_idx_tree_impl.F90

@@ -0,0 +1,329 @@
+!
+!                Parallel Sparse BLAS  version 3.5
+!      (C) Copyright 2006-2018
+!        Salvatore Filippone
+!        Alfredo Buttari
+!
+!    Redistribution and use in source and binary forms, with or without
+!    modification, are permitted provided that the following conditions
+!    are met:
+!      1. Redistributions of source code must retain the above copyright
+!         notice, this list of conditions and the following disclaimer.
+!      2. Redistributions in binary form must reproduce the above copyright
+!         notice, this list of conditions, and the following disclaimer in the
+!         documentation and/or other materials provided with the distribution.
+!      3. The name of the PSBLAS group or the names of its contributors may
+!         not be used to endorse or promote products derived from this
+!         software without specific written permission.
+!
+!    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+!    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+!    TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+!    PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE PSBLAS GROUP OR ITS CONTRIBUTORS
+!    BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+!    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+!    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+!    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+!    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+!    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+!    POSSIBILITY OF SUCH DAMAGE.
+!
+!
+!
+! package: psb_z_rb_idx_tree_impl
+! 
+! Red black tree implementation ordered by index
+!
+! Each node contains and index and a double precision value
+!
+! The tree should always be well balanced
+!
+! inserting a node with an existing index will 
+! add up the new value to the old one
+! Contributed by Dimitri Walther
+! 
+subroutine psb_z_rb_idx_tree_insert(this, idx, val)
+  use psb_z_rb_idx_tree_mod, psb_protect_name => psb_z_rb_idx_tree_insert
+  implicit none
+  class(psb_z_rb_idx_tree), intent(inout) :: this
+  integer(psb_ipk_), intent(in) :: idx
+  complex(psb_dpk_), intent(in) :: val
+
+  character(len=22) :: name
+  type(psb_z_rb_idx_node), pointer :: new_node
+  type(psb_z_rb_idx_node), pointer :: current, previous
+  name='psb_rb_idx_tree_insert'
+
+  allocate(new_node)
+  new_node%idx = idx
+  new_node%val = val
+  nullify(new_node%left)
+  nullify(new_node%right)
+  nullify(new_node%parent)
+  new_node%is_red = .true.
+
+
+  if (.not. associated(this%root)) then
+    this%root => new_node
+    this%nnz = 1
+    new_node%is_red = .false.
+    return
+  end if
+
+  current => this%root
+
+  do while (associated(current))
+    previous => current
+
+    if (idx == current%idx) then
+      current%val = current%val + val
+      deallocate(new_node)
+      return
+    else if (idx < current%idx) then
+      current => current%left
+    else
+
+      current => current%right
+    end if
+  end do
+
+  if (idx < previous%idx) then
+    new_node%parent => previous
+    previous%left => new_node
+  else
+    new_node%parent => previous
+    previous%right => new_node
+  end if
+
+  call psb_z_rb_idx_tree_fix_insertion(this, new_node)
+
+  this%nnz = this%nnz + 1
+end subroutine psb_z_rb_idx_tree_insert
+
+subroutine psb_z_rb_idx_tree_fix_insertion(this, node)
+  use psb_z_rb_idx_tree_mod, psb_protect_name => psb_z_rb_idx_tree_fix_insertion
+  implicit none
+  class(psb_z_rb_idx_tree), intent(inout) :: this
+  type(psb_z_rb_idx_node), pointer, intent(inout) :: node
+
+  character(len=29) :: name
+  type(psb_z_rb_idx_node), pointer :: current, parent, grand_parent, uncle
+  name = 'psb_rb_idx_tree_fix_insertion'
+
+  current => node
+  parent => current%parent
+  do while(associated(parent) .and. parent%is_red)
+    ! grand parent exist because root can't be red
+    grand_parent => parent%parent
+    if (parent%idx < grand_parent%idx) then
+      uncle => grand_parent%right
+    else
+      uncle => grand_parent%left
+    end if
+
+    if (associated(uncle) .and. uncle%is_red) then
+      parent%is_red = .false.
+      uncle%is_red = .false.
+      grand_parent%is_red = .true.
+      current => grand_parent
+      parent => current%parent
+
+      ! Left-Left case
+    else if (current%idx < parent%idx .and. &
+         parent%idx < grand_parent%idx) then
+      call psb_z_rb_idx_tree_rotate_right(grand_parent)
+      call psb_z_rb_idx_tree_swap_colors(parent, grand_parent)
+
+      if (this%root%idx == grand_parent%idx) this%root => parent
+
+      return
+      ! Left-Right case
+    else if (current%idx > parent%idx .and. &
+         parent%idx < grand_parent%idx) then
+      call psb_z_rb_idx_tree_rotate_left(parent)
+      call psb_z_rb_idx_tree_rotate_right(grand_parent)
+      call psb_z_rb_idx_tree_swap_colors(current, grand_parent)
+
+      if (this%root%idx == grand_parent%idx) this%root => current
+
+      return
+      ! Right-Right case
+    else if (current%idx > parent%idx .and. &
+         parent%idx > grand_parent%idx) then
+      call psb_z_rb_idx_tree_rotate_left(grand_parent)
+      call psb_z_rb_idx_tree_swap_colors(parent, grand_parent)
+
+      if (this%root%idx == grand_parent%idx) this%root => parent
+
+      return
+      ! Right-Left case
+    else
+      call psb_z_rb_idx_tree_rotate_right(parent)
+      call psb_z_rb_idx_tree_rotate_left(grand_parent)
+      call psb_z_rb_idx_tree_swap_colors(current, grand_parent)
+
+      if (this%root%idx == grand_parent%idx) this%root => current
+
+      return
+    end if
+  end do
+
+  this%root%is_red = .false.
+end subroutine psb_z_rb_idx_tree_fix_insertion
+
+subroutine psb_z_rb_idx_tree_swap_colors(n1, n2)
+  use psb_z_rb_idx_tree_mod, psb_protect_name => psb_z_rb_idx_tree_swap_colors
+  implicit none
+  type(psb_z_rb_idx_node), pointer, intent(inout) :: n1, n2
+
+  character(len=27) :: name
+  logical :: tmp
+  name='psb_rb_idx_tree_swap_colors'
+
+  tmp = n1%is_red
+  n1%is_red = n2%is_red
+  n2%is_red = tmp
+end subroutine psb_z_rb_idx_tree_swap_colors
+
+subroutine psb_z_rb_idx_tree_rotate_right(node)
+  use psb_z_rb_idx_tree_mod, psb_protect_name => psb_z_rb_idx_tree_rotate_right
+  implicit none
+  type(psb_z_rb_idx_node), pointer, intent(inout) :: node
+
+  character(len=28) :: name
+  type(psb_z_rb_idx_node), pointer :: l, lr
+  name='psb_rb_idx_tree_rotate_right'
+
+  if (.not. associated(node%left)) return
+
+  l => node%left
+  lr => l%right
+  node%left => lr
+
+  if (associated(lr)) lr%parent => node
+
+  if (associated(node%parent)) then
+    if (node%idx < node%parent%idx) then
+      node%parent%left => l
+    else
+      node%parent%right => l
+    end if
+  end if
+
+  l%parent => node%parent
+  node%parent => l
+
+  l%right => node
+end subroutine psb_z_rb_idx_tree_rotate_right
+
+subroutine psb_z_rb_idx_tree_rotate_left(node)
+  use psb_z_rb_idx_tree_mod, psb_protect_name => psb_z_rb_idx_tree_rotate_left
+  implicit none
+  type(psb_z_rb_idx_node), pointer, intent(inout) :: node
+
+  character(len=27) :: name
+  type(psb_z_rb_idx_node), pointer :: r, rl
+  name='psb_rb_idx_tree_rotate_left'
+
+  if (.not. associated(node%right)) return
+
+  r => node%right
+  rl => r%left
+  node%right => rl
+
+  if (associated(rl)) rl%parent => node
+
+  if (associated(node%parent)) then
+    if (node%idx < node%parent%idx) then
+      node%parent%left => r
+    else
+      node%parent%right => r
+    end if
+  end if
+
+  r%parent => node%parent
+  node%parent => r
+
+  r%left => node
+end subroutine psb_z_rb_idx_tree_rotate_left
+
+subroutine psb_z_rb_idx_tree_scalar_sparse_row_mul(tree, scalar, mat, row_num)
+  use psb_z_rb_idx_tree_mod, psb_protect_name => psb_z_rb_idx_tree_scalar_sparse_row_mul
+  use psb_z_csr_mat_mod, only : psb_z_csr_sparse_mat
+  implicit none
+  type(psb_z_rb_idx_tree), intent(inout) :: tree
+  complex(psb_dpk_), intent(in) :: scalar
+  type(psb_z_csr_sparse_mat), intent(in) :: mat
+  integer(psb_ipk_), intent(in) :: row_num
+
+  character(len=37) :: name
+  integer(psb_ipk_) :: i
+  name='psb_rb_idx_tree_scalar_sparse_row_mul'
+
+  do i = mat%irp(row_num), mat%irp(row_num + 1) - 1
+    call tree%insert(mat%ja(i),scalar * mat%val(i))
+  end do
+
+end subroutine psb_z_rb_idx_tree_scalar_sparse_row_mul
+
+subroutine psb_z_rb_idx_tree_merge(trees, mat)
+#if defined(OPENMP)
+  use omp_lib
+#endif
+  use psb_realloc_mod
+  use psb_z_rb_idx_tree_mod, psb_protect_name => psb_z_rb_idx_tree_merge
+  use psb_z_csr_mat_mod, only : psb_z_csr_sparse_mat
+  implicit none
+  type(psb_z_rb_idx_tree), allocatable, intent(inout) :: trees(:)
+  type(psb_z_csr_sparse_mat), intent(inout) :: mat
+
+  character(len=21) :: name
+  integer(psb_ipk_) :: i, j, rows, info, nnz
+  type(psb_z_rb_idx_node), pointer :: current, previous
+  name='psb_rb_idx_tree_merge'
+
+  rows = size(trees)
+
+  mat%irp(1) = 1
+
+  do i=1, rows
+    mat%irp(i + 1) = mat%irp(i) + trees(i)%nnz
+  end do
+
+  nnz = mat%irp(rows + 1)
+  call psb_realloc(nnz, mat%val, info)
+  call psb_realloc(nnz, mat%ja, info)
+
+#if defined(OPENMP)
+  !$omp parallel do schedule(static), private(current, previous, j)
+#endif
+  do i = 1, size(trees)
+    j = 0
+    current => trees(i)%root
+    do while(associated(current))
+      ! go to the left-most node
+      do while(associated(current%left))
+        current => current%left
+      end do
+      mat%val(j + mat%irp(i)) = current%val
+      mat%ja(j + mat%irp(i)) = current%idx
+      j = j + 1
+
+      previous => current
+      if (associated(current%right)) then
+        if (associated(current%parent)) then
+          current%parent%left => current%right
+        end if
+        current%right%parent => current%parent
+        current => current%right
+      else
+        current => current%parent
+        if (associated(current)) nullify(current%left)
+      end if
+      deallocate(previous)
+    end do
+  end do
+#if defined(OPENMP)
+  !$omp end parallel do
+#endif
+end subroutine psb_z_rb_idx_tree_merge