diff --git a/base/modules/psblas/psb_c_psblas_mod.F90 b/base/modules/psblas/psb_c_psblas_mod.F90
index a9c37d99..9a884b8a 100644
--- a/base/modules/psblas/psb_c_psblas_mod.F90
+++ b/base/modules/psblas/psb_c_psblas_mod.F90
@@ -523,4 +523,5 @@ module psb_c_psblas_mod
     end subroutine psb_ccmp_vect
   end interface
 
+
 end module psb_c_psblas_mod
diff --git a/base/modules/psblas/psb_d_psblas_mod.F90 b/base/modules/psblas/psb_d_psblas_mod.F90
index 4303f8bc..28cfa068 100644
--- a/base/modules/psblas/psb_d_psblas_mod.F90
+++ b/base/modules/psblas/psb_d_psblas_mod.F90
@@ -523,4 +523,17 @@ module psb_d_psblas_mod
     end subroutine psb_dcmp_vect
   end interface
 
+  interface psb_mask
+    subroutine psb_dmask_vect(c,x,m,t,desc_a,info)
+      import :: psb_desc_type, psb_ipk_, &
+           & psb_d_vect_type, psb_dpk_
+      type(psb_d_vect_type), intent (inout) :: c
+      type(psb_d_vect_type), intent (inout) :: x
+      type(psb_d_vect_type), intent (inout) :: m
+      logical, intent(out)                    :: t
+      type(psb_desc_type), intent (in)        :: desc_a
+      integer(psb_ipk_), intent(out)          :: info
+    end subroutine psb_dmask_vect
+  end interface
+
 end module psb_d_psblas_mod
diff --git a/base/modules/psblas/psb_s_psblas_mod.F90 b/base/modules/psblas/psb_s_psblas_mod.F90
index 04969899..b1aba86e 100644
--- a/base/modules/psblas/psb_s_psblas_mod.F90
+++ b/base/modules/psblas/psb_s_psblas_mod.F90
@@ -523,4 +523,17 @@ module psb_s_psblas_mod
     end subroutine psb_scmp_vect
   end interface
 
+  interface psb_mask
+    subroutine psb_smask_vect(c,x,m,t,desc_a,info)
+      import :: psb_desc_type, psb_ipk_, &
+           & psb_s_vect_type, psb_spk_
+      type(psb_s_vect_type), intent (inout) :: c
+      type(psb_s_vect_type), intent (inout) :: x
+      type(psb_s_vect_type), intent (inout) :: m
+      logical, intent(out)                    :: t
+      type(psb_desc_type), intent (in)        :: desc_a
+      integer(psb_ipk_), intent(out)          :: info
+    end subroutine psb_smask_vect
+  end interface
+
 end module psb_s_psblas_mod
diff --git a/base/modules/psblas/psb_z_psblas_mod.F90 b/base/modules/psblas/psb_z_psblas_mod.F90
index dc4d0262..284a48b9 100644
--- a/base/modules/psblas/psb_z_psblas_mod.F90
+++ b/base/modules/psblas/psb_z_psblas_mod.F90
@@ -523,4 +523,5 @@ module psb_z_psblas_mod
     end subroutine psb_zcmp_vect
   end interface
 
+
 end module psb_z_psblas_mod
diff --git a/base/modules/serial/psb_c_base_vect_mod.f90 b/base/modules/serial/psb_c_base_vect_mod.f90
index c67aa5d2..9ec9fa47 100644
--- a/base/modules/serial/psb_c_base_vect_mod.f90
+++ b/base/modules/serial/psb_c_base_vect_mod.f90
@@ -194,6 +194,7 @@ module psb_c_base_vect_mod
     procedure, pass(z) :: acmp_v2   => c_base_acmp_v2
     generic, public    :: acmp      => acmp_a2,acmp_v2
 
+
   end type psb_c_base_vect_type
 
   public  :: psb_c_base_vect
@@ -1718,6 +1719,7 @@ contains
 
   end subroutine c_base_sctb_buf
 
+
 end module psb_c_base_vect_mod
 
 
diff --git a/base/modules/serial/psb_c_vect_mod.F90 b/base/modules/serial/psb_c_vect_mod.F90
index 192d94e4..b8e437af 100644
--- a/base/modules/serial/psb_c_vect_mod.F90
+++ b/base/modules/serial/psb_c_vect_mod.F90
@@ -118,6 +118,7 @@ module psb_c_vect_mod
     procedure, pass(z) :: acmp_v2   => c_vect_acmp_v2
     generic, public    :: acmp      => acmp_a2, acmp_v2
 
+
   end type psb_c_vect_type
 
   public  :: psb_c_vect
@@ -1002,6 +1003,7 @@ contains
   end function c_vect_asum
 
 
+
 end module psb_c_vect_mod
 
 
diff --git a/base/modules/serial/psb_d_base_vect_mod.f90 b/base/modules/serial/psb_d_base_vect_mod.f90
index a1a47500..8fb287c1 100644
--- a/base/modules/serial/psb_d_base_vect_mod.f90
+++ b/base/modules/serial/psb_d_base_vect_mod.f90
@@ -194,6 +194,10 @@ module psb_d_base_vect_mod
     procedure, pass(z) :: acmp_v2   => d_base_acmp_v2
     generic, public    :: acmp      => acmp_a2,acmp_v2
 
+procedure, pass(m) :: mask_v => d_base_mask_v
+procedure, pass(m) :: mask_a => d_base_mask_a
+generic, public    :: mask => mask_a, mask_v
+
   end type psb_d_base_vect_type
 
   public  :: psb_d_base_vect
@@ -1718,6 +1722,99 @@ contains
 
   end subroutine d_base_sctb_buf
 
+  !
+  !> Function  base_mask_a
+  !! \memberof  psb_d_base_vect_type
+  !! \brief Peform constraint tests looking at the value of c
+  !! \param x The array to be compared
+  !! \param c The array containing the information on the type of test to be
+  !! performed, if c(i) = 2 ">0", if c(i) = 1 ">=0", if c(i) = 0 no test, if
+  !! c(i) =-1 "<=0", if c(i) = -2 "< 0"
+  !! \param m The vector containing the result of the comparison 1.0 for a
+  !! failed test, and 0.0 for a passed one.
+  !! \param t logical resulting from an and operation on all the tests
+  !! \param info return code
+  !
+  subroutine d_base_mask_a(c,x,m,t,info)
+    use psi_serial_mod
+    implicit none
+    real(psb_dpk_), intent(inout)               :: c(:)
+    real(psb_dpk_), intent(inout)               :: x(:)
+    class(psb_d_base_vect_type), intent(inout)  :: m
+    integer(psb_ipk_), intent(out)                :: info
+    logical, intent(out)                          :: t
+    integer(psb_ipk_) :: i, n
+
+    if (m%is_dev()) call m%sync()
+    t = .true.
+
+    n = size(x)
+    do i = 1, n, 1
+      if (c(i).eq.2_psb_dpk_) then
+        if ( x(i) > dzero ) then
+          m%v(i) = 0_psb_dpk_
+        else
+          m%v(i) = 1_psb_dpk_
+          t = .false.
+        end if
+      elseif (c(i).eq.1_psb_dpk_) then
+        if ( x(i) >= dzero ) then
+          m%v(i) = 0_psb_dpk_
+        else
+          m%v(i) = 1_psb_dpk_
+          t = .false.
+        end if
+      elseif (c(i).eq.-1_psb_dpk_) then
+        if ( x(i) <= dzero ) then
+          m%v(i) = 0_psb_dpk_
+        else
+          m%v(i) = 1_psb_dpk_
+          t = .false.
+        end if
+      elseif (c(i).eq.-2_psb_dpk_) then
+        if ( x(i) < dzero ) then
+          m%v(i) = 0_psb_dpk_
+        else
+          m%v(i) = 1_psb_dpk_
+          t = .false.
+        end if
+      else
+          m%v(i) = 0_psb_dpk_
+      end if
+    end do
+    info = 0
+
+  end subroutine d_base_mask_a
+  !
+  !> Function  base_mask_v
+  !! \memberof  psb_d_base_vect_type
+  !! \brief Peform constraint tests looking at the value of c
+  !! \param x The vector to be compared
+  !! \param c The vector containing the information on the type of test to be
+  !! performed, if c(i) = 2 ">0", if c(i) = 1 ">=0", if c(i) = 0 no test, if
+  !! c(i) =-1 "<=0", if c(i) = -2 "< 0"
+  !! \param m The vector containing the result of the comparison 1.0 for a
+  !! failed test, and 0.0 for a passed one.
+  !! \param t logical resulting from an and operation on all the tests
+  !! \param info return code
+  !
+  subroutine d_base_mask_v(c,x,m,t,info)
+    use psi_serial_mod
+    implicit none
+    class(psb_d_base_vect_type), intent(inout)  :: c
+    class(psb_d_base_vect_type), intent(inout)  :: x
+    class(psb_d_base_vect_type), intent(inout)  :: m
+    integer(psb_ipk_), intent(out)                :: info
+    logical, intent(out)                          :: t
+
+    info = 0
+    if (x%is_dev()) call x%sync()
+    if (c%is_dev()) call c%sync()
+
+    call m%mask(x%v,c%v,t,info)
+  end subroutine d_base_mask_v
+
+
 end module psb_d_base_vect_mod
 
 
diff --git a/base/modules/serial/psb_d_vect_mod.F90 b/base/modules/serial/psb_d_vect_mod.F90
index 18525b25..4c0cc6e8 100644
--- a/base/modules/serial/psb_d_vect_mod.F90
+++ b/base/modules/serial/psb_d_vect_mod.F90
@@ -118,6 +118,10 @@ module psb_d_vect_mod
     procedure, pass(z) :: acmp_v2   => d_vect_acmp_v2
     generic, public    :: acmp      => acmp_a2, acmp_v2
 
+    procedure, pass(m) :: mask_v => d_vect_mask_v
+    procedure, pass(m) :: mask_a => d_vect_mask_a
+    generic, public    :: mask => mask_a, mask_v
+
   end type psb_d_vect_type
 
   public  :: psb_d_vect
@@ -1002,6 +1006,36 @@ contains
   end function d_vect_asum
 
 
+  subroutine d_vect_mask_a(c,x,m,t,info)
+    use psi_serial_mod
+    implicit none
+    real(psb_dpk_), intent(inout)          :: c(:)
+    real(psb_dpk_), intent(inout)          :: x(:)
+    logical, intent(out)                     :: t;
+    class(psb_d_vect_type), intent(inout)  :: m
+    integer(psb_ipk_), intent(out)           :: info
+
+    info = 0
+    if (allocated(m%v)) &
+         & call m%mask(c,x,t,info)
+
+  end subroutine d_vect_mask_a
+
+  subroutine d_vect_mask_v(c,x,m,t,info)
+    use psi_serial_mod
+    implicit none
+    class(psb_d_vect_type), intent(inout)  :: c
+    class(psb_d_vect_type), intent(inout)  :: x
+    class(psb_d_vect_type), intent(inout)  :: m
+    logical, intent(out)                     :: t;
+    integer(psb_ipk_), intent(out)           :: info
+
+    info = 0
+    if (allocated(x%v).and.allocated(c%v)) &
+         & call m%v%mask(x%v,c%v,t,info)
+
+  end subroutine d_vect_mask_v
+
 end module psb_d_vect_mod
 
 
diff --git a/base/modules/serial/psb_i_base_vect_mod.f90 b/base/modules/serial/psb_i_base_vect_mod.f90
index 438a10ae..642ff4ff 100644
--- a/base/modules/serial/psb_i_base_vect_mod.f90
+++ b/base/modules/serial/psb_i_base_vect_mod.f90
@@ -143,6 +143,7 @@ module psb_i_base_vect_mod
 
 
 
+
   end type psb_i_base_vect_type
 
   public  :: psb_i_base_vect
@@ -974,6 +975,7 @@ contains
 
   end subroutine i_base_sctb_buf
 
+
 end module psb_i_base_vect_mod
 
 
diff --git a/base/modules/serial/psb_i_vect_mod.F90 b/base/modules/serial/psb_i_vect_mod.F90
index 8b4a21a7..13a04e00 100644
--- a/base/modules/serial/psb_i_vect_mod.F90
+++ b/base/modules/serial/psb_i_vect_mod.F90
@@ -80,6 +80,7 @@ module psb_i_vect_mod
     procedure, pass(x) :: set_sync => i_vect_set_sync
 
 
+
   end type psb_i_vect_type
 
   public  :: psb_i_vect
@@ -551,6 +552,7 @@ contains
   end function i_vect_is_dev
 
 
+
 end module psb_i_vect_mod
 
 
diff --git a/base/modules/serial/psb_l_base_vect_mod.f90 b/base/modules/serial/psb_l_base_vect_mod.f90
index 05275759..fe25d30d 100644
--- a/base/modules/serial/psb_l_base_vect_mod.f90
+++ b/base/modules/serial/psb_l_base_vect_mod.f90
@@ -144,6 +144,7 @@ module psb_l_base_vect_mod
 
 
 
+
   end type psb_l_base_vect_type
 
   public  :: psb_l_base_vect
@@ -975,6 +976,7 @@ contains
 
   end subroutine l_base_sctb_buf
 
+
 end module psb_l_base_vect_mod
 
 
diff --git a/base/modules/serial/psb_l_vect_mod.F90 b/base/modules/serial/psb_l_vect_mod.F90
index 629c843d..926982fa 100644
--- a/base/modules/serial/psb_l_vect_mod.F90
+++ b/base/modules/serial/psb_l_vect_mod.F90
@@ -81,6 +81,7 @@ module psb_l_vect_mod
     procedure, pass(x) :: set_sync => l_vect_set_sync
 
 
+
   end type psb_l_vect_type
 
   public  :: psb_l_vect
@@ -552,6 +553,7 @@ contains
   end function l_vect_is_dev
 
 
+
 end module psb_l_vect_mod
 
 
diff --git a/base/modules/serial/psb_s_base_vect_mod.f90 b/base/modules/serial/psb_s_base_vect_mod.f90
index 4ce6de51..d1dbb20c 100644
--- a/base/modules/serial/psb_s_base_vect_mod.f90
+++ b/base/modules/serial/psb_s_base_vect_mod.f90
@@ -194,6 +194,10 @@ module psb_s_base_vect_mod
     procedure, pass(z) :: acmp_v2   => s_base_acmp_v2
     generic, public    :: acmp      => acmp_a2,acmp_v2
 
+procedure, pass(m) :: mask_v => s_base_mask_v
+procedure, pass(m) :: mask_a => s_base_mask_a
+generic, public    :: mask => mask_a, mask_v
+
   end type psb_s_base_vect_type
 
   public  :: psb_s_base_vect
@@ -1718,6 +1722,99 @@ contains
 
   end subroutine s_base_sctb_buf
 
+  !
+  !> Function  base_mask_a
+  !! \memberof  psb_s_base_vect_type
+  !! \brief Peform constraint tests looking at the value of c
+  !! \param x The array to be compared
+  !! \param c The array containing the information on the type of test to be
+  !! performed, if c(i) = 2 ">0", if c(i) = 1 ">=0", if c(i) = 0 no test, if
+  !! c(i) =-1 "<=0", if c(i) = -2 "< 0"
+  !! \param m The vector containing the result of the comparison 1.0 for a
+  !! failed test, and 0.0 for a passed one.
+  !! \param t logical resulting from an and operation on all the tests
+  !! \param info return code
+  !
+  subroutine s_base_mask_a(c,x,m,t,info)
+    use psi_serial_mod
+    implicit none
+    real(psb_spk_), intent(inout)               :: c(:)
+    real(psb_spk_), intent(inout)               :: x(:)
+    class(psb_s_base_vect_type), intent(inout)  :: m
+    integer(psb_ipk_), intent(out)                :: info
+    logical, intent(out)                          :: t
+    integer(psb_ipk_) :: i, n
+
+    if (m%is_dev()) call m%sync()
+    t = .true.
+
+    n = size(x)
+    do i = 1, n, 1
+      if (c(i).eq.2_psb_spk_) then
+        if ( x(i) > szero ) then
+          m%v(i) = 0_psb_spk_
+        else
+          m%v(i) = 1_psb_spk_
+          t = .false.
+        end if
+      elseif (c(i).eq.1_psb_spk_) then
+        if ( x(i) >= szero ) then
+          m%v(i) = 0_psb_spk_
+        else
+          m%v(i) = 1_psb_spk_
+          t = .false.
+        end if
+      elseif (c(i).eq.-1_psb_spk_) then
+        if ( x(i) <= szero ) then
+          m%v(i) = 0_psb_spk_
+        else
+          m%v(i) = 1_psb_spk_
+          t = .false.
+        end if
+      elseif (c(i).eq.-2_psb_spk_) then
+        if ( x(i) < szero ) then
+          m%v(i) = 0_psb_spk_
+        else
+          m%v(i) = 1_psb_spk_
+          t = .false.
+        end if
+      else
+          m%v(i) = 0_psb_spk_
+      end if
+    end do
+    info = 0
+
+  end subroutine s_base_mask_a
+  !
+  !> Function  base_mask_v
+  !! \memberof  psb_s_base_vect_type
+  !! \brief Peform constraint tests looking at the value of c
+  !! \param x The vector to be compared
+  !! \param c The vector containing the information on the type of test to be
+  !! performed, if c(i) = 2 ">0", if c(i) = 1 ">=0", if c(i) = 0 no test, if
+  !! c(i) =-1 "<=0", if c(i) = -2 "< 0"
+  !! \param m The vector containing the result of the comparison 1.0 for a
+  !! failed test, and 0.0 for a passed one.
+  !! \param t logical resulting from an and operation on all the tests
+  !! \param info return code
+  !
+  subroutine s_base_mask_v(c,x,m,t,info)
+    use psi_serial_mod
+    implicit none
+    class(psb_s_base_vect_type), intent(inout)  :: c
+    class(psb_s_base_vect_type), intent(inout)  :: x
+    class(psb_s_base_vect_type), intent(inout)  :: m
+    integer(psb_ipk_), intent(out)                :: info
+    logical, intent(out)                          :: t
+
+    info = 0
+    if (x%is_dev()) call x%sync()
+    if (c%is_dev()) call c%sync()
+
+    call m%mask(x%v,c%v,t,info)
+  end subroutine s_base_mask_v
+
+
 end module psb_s_base_vect_mod
 
 
diff --git a/base/modules/serial/psb_s_vect_mod.F90 b/base/modules/serial/psb_s_vect_mod.F90
index 4e24e726..5f0fd6de 100644
--- a/base/modules/serial/psb_s_vect_mod.F90
+++ b/base/modules/serial/psb_s_vect_mod.F90
@@ -118,6 +118,10 @@ module psb_s_vect_mod
     procedure, pass(z) :: acmp_v2   => s_vect_acmp_v2
     generic, public    :: acmp      => acmp_a2, acmp_v2
 
+    procedure, pass(m) :: mask_v => s_vect_mask_v
+    procedure, pass(m) :: mask_a => s_vect_mask_a
+    generic, public    :: mask => mask_a, mask_v
+
   end type psb_s_vect_type
 
   public  :: psb_s_vect
@@ -1002,6 +1006,36 @@ contains
   end function s_vect_asum
 
 
+  subroutine s_vect_mask_a(c,x,m,t,info)
+    use psi_serial_mod
+    implicit none
+    real(psb_spk_), intent(inout)          :: c(:)
+    real(psb_spk_), intent(inout)          :: x(:)
+    logical, intent(out)                     :: t;
+    class(psb_s_vect_type), intent(inout)  :: m
+    integer(psb_ipk_), intent(out)           :: info
+
+    info = 0
+    if (allocated(m%v)) &
+         & call m%mask(c,x,t,info)
+
+  end subroutine s_vect_mask_a
+
+  subroutine s_vect_mask_v(c,x,m,t,info)
+    use psi_serial_mod
+    implicit none
+    class(psb_s_vect_type), intent(inout)  :: c
+    class(psb_s_vect_type), intent(inout)  :: x
+    class(psb_s_vect_type), intent(inout)  :: m
+    logical, intent(out)                     :: t;
+    integer(psb_ipk_), intent(out)           :: info
+
+    info = 0
+    if (allocated(x%v).and.allocated(c%v)) &
+         & call m%v%mask(x%v,c%v,t,info)
+
+  end subroutine s_vect_mask_v
+
 end module psb_s_vect_mod
 
 
diff --git a/base/modules/serial/psb_z_base_vect_mod.f90 b/base/modules/serial/psb_z_base_vect_mod.f90
index c73cdd65..ab551130 100644
--- a/base/modules/serial/psb_z_base_vect_mod.f90
+++ b/base/modules/serial/psb_z_base_vect_mod.f90
@@ -194,6 +194,7 @@ module psb_z_base_vect_mod
     procedure, pass(z) :: acmp_v2   => z_base_acmp_v2
     generic, public    :: acmp      => acmp_a2,acmp_v2
 
+
   end type psb_z_base_vect_type
 
   public  :: psb_z_base_vect
@@ -1718,6 +1719,7 @@ contains
 
   end subroutine z_base_sctb_buf
 
+
 end module psb_z_base_vect_mod
 
 
diff --git a/base/modules/serial/psb_z_vect_mod.F90 b/base/modules/serial/psb_z_vect_mod.F90
index b8a6de22..0bf21205 100644
--- a/base/modules/serial/psb_z_vect_mod.F90
+++ b/base/modules/serial/psb_z_vect_mod.F90
@@ -118,6 +118,7 @@ module psb_z_vect_mod
     procedure, pass(z) :: acmp_v2   => z_vect_acmp_v2
     generic, public    :: acmp      => acmp_a2, acmp_v2
 
+
   end type psb_z_vect_type
 
   public  :: psb_z_vect
@@ -1002,6 +1003,7 @@ contains
   end function z_vect_asum
 
 
+
 end module psb_z_vect_mod
 
 
diff --git a/base/psblas/psb_ccmp_vect.f90 b/base/psblas/psb_ccmp_vect.f90
index e808836f..a0429852 100644
--- a/base/psblas/psb_ccmp_vect.f90
+++ b/base/psblas/psb_ccmp_vect.f90
@@ -103,3 +103,4 @@ subroutine psb_ccmp_vect(x,c,z,desc_a,info)
   return
 
 end subroutine psb_ccmp_vect
+
diff --git a/base/psblas/psb_dcmp_vect.f90 b/base/psblas/psb_dcmp_vect.f90
index 85113bcd..c3b18a7b 100644
--- a/base/psblas/psb_dcmp_vect.f90
+++ b/base/psblas/psb_dcmp_vect.f90
@@ -103,3 +103,124 @@ subroutine psb_dcmp_vect(x,c,z,desc_a,info)
   return
 
 end subroutine psb_dcmp_vect
+
+!
+!                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.
+!
+!
+! File: psb_dmask_vect
+
+subroutine psb_dmask_vect(c,x,m,t,desc_a,info)
+  use psb_base_mod, psb_protect_name => psb_dmask_vect
+  implicit none
+  type(psb_d_vect_type), intent (inout) :: c
+  type(psb_d_vect_type), intent (inout) :: x
+  type(psb_d_vect_type), intent (inout) :: m
+  logical, intent(out)                    :: t
+  type(psb_desc_type), intent (in)        :: desc_a
+  integer(psb_ipk_), intent(out)          :: info
+
+  ! locals
+  integer(psb_ipk_) :: ictxt, np, me,&
+       & err_act, iix, jjx, iiy, jjy
+  integer(psb_lpk_) :: ix, ijx, iy, ijy, mm
+  character(len=20)        :: name, ch_err
+
+  name='psb_d_mask_vect'
+  if (psb_errstatus_fatal()) return
+  info=psb_success_
+  call psb_erractionsave(err_act)
+
+  ictxt=desc_a%get_context()
+
+  call psb_info(ictxt, me, np)
+  if (np == -ione) then
+    info = psb_err_context_error_
+    call psb_errpush(info,name)
+    goto 9999
+  endif
+  if (.not.allocated(c%v)) then
+    info = psb_err_invalid_vect_state_
+    call psb_errpush(info,name)
+    goto 9999
+  endif
+  if (.not.allocated(x%v)) then
+    info = psb_err_invalid_vect_state_
+    call psb_errpush(info,name)
+    goto 9999
+  endif
+  if (.not.allocated(m%v)) then
+    info = psb_err_invalid_vect_state_
+    call psb_errpush(info,name)
+    goto 9999
+  endif
+
+  ix = ione
+  iy = ione
+
+  mm = desc_a%get_global_rows()
+
+  ! check vector correctness
+  call psb_chkvect(mm,lone,c%get_nrows(),ix,lone,desc_a,info,iix,jjx)
+  if(info /= psb_success_) then
+    info=psb_err_from_subroutine_
+    ch_err='psb_chkvect 1'
+    call psb_errpush(info,name,a_err=ch_err)
+    goto 9999
+  end if
+  call psb_chkvect(mm,lone,x%get_nrows(),iy,lone,desc_a,info,iiy,jjy)
+  if(info /= psb_success_) then
+    info=psb_err_from_subroutine_
+    ch_err='psb_chkvect 2'
+    call psb_errpush(info,name,a_err=ch_err)
+    goto 9999
+  end if
+  call psb_chkvect(mm,lone,m%get_nrows(),iy,lone,desc_a,info,iiy,jjy)
+  if(info /= psb_success_) then
+    info=psb_err_from_subroutine_
+    ch_err='psb_chkvect 2'
+    call psb_errpush(info,name,a_err=ch_err)
+    goto 9999
+  end if
+
+  if(desc_a%get_local_rows() > 0) then
+    call m%mask(c,x,t,info)
+  end if
+
+  call psb_erractionrestore(err_act)
+  return
+
+9999 call psb_error_handler(ictxt,err_act)
+
+  return
+
+end subroutine psb_dmask_vect
+
+
diff --git a/base/psblas/psb_scmp_vect.f90 b/base/psblas/psb_scmp_vect.f90
index 73865857..a33a0ec9 100644
--- a/base/psblas/psb_scmp_vect.f90
+++ b/base/psblas/psb_scmp_vect.f90
@@ -103,3 +103,124 @@ subroutine psb_scmp_vect(x,c,z,desc_a,info)
   return
 
 end subroutine psb_scmp_vect
+
+!
+!                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.
+!
+!
+! File: psb_smask_vect
+
+subroutine psb_smask_vect(c,x,m,t,desc_a,info)
+  use psb_base_mod, psb_protect_name => psb_smask_vect
+  implicit none
+  type(psb_s_vect_type), intent (inout) :: c
+  type(psb_s_vect_type), intent (inout) :: x
+  type(psb_s_vect_type), intent (inout) :: m
+  logical, intent(out)                    :: t
+  type(psb_desc_type), intent (in)        :: desc_a
+  integer(psb_ipk_), intent(out)          :: info
+
+  ! locals
+  integer(psb_ipk_) :: ictxt, np, me,&
+       & err_act, iix, jjx, iiy, jjy
+  integer(psb_lpk_) :: ix, ijx, iy, ijy, mm
+  character(len=20)        :: name, ch_err
+
+  name='psb_s_mask_vect'
+  if (psb_errstatus_fatal()) return
+  info=psb_success_
+  call psb_erractionsave(err_act)
+
+  ictxt=desc_a%get_context()
+
+  call psb_info(ictxt, me, np)
+  if (np == -ione) then
+    info = psb_err_context_error_
+    call psb_errpush(info,name)
+    goto 9999
+  endif
+  if (.not.allocated(c%v)) then
+    info = psb_err_invalid_vect_state_
+    call psb_errpush(info,name)
+    goto 9999
+  endif
+  if (.not.allocated(x%v)) then
+    info = psb_err_invalid_vect_state_
+    call psb_errpush(info,name)
+    goto 9999
+  endif
+  if (.not.allocated(m%v)) then
+    info = psb_err_invalid_vect_state_
+    call psb_errpush(info,name)
+    goto 9999
+  endif
+
+  ix = ione
+  iy = ione
+
+  mm = desc_a%get_global_rows()
+
+  ! check vector correctness
+  call psb_chkvect(mm,lone,c%get_nrows(),ix,lone,desc_a,info,iix,jjx)
+  if(info /= psb_success_) then
+    info=psb_err_from_subroutine_
+    ch_err='psb_chkvect 1'
+    call psb_errpush(info,name,a_err=ch_err)
+    goto 9999
+  end if
+  call psb_chkvect(mm,lone,x%get_nrows(),iy,lone,desc_a,info,iiy,jjy)
+  if(info /= psb_success_) then
+    info=psb_err_from_subroutine_
+    ch_err='psb_chkvect 2'
+    call psb_errpush(info,name,a_err=ch_err)
+    goto 9999
+  end if
+  call psb_chkvect(mm,lone,m%get_nrows(),iy,lone,desc_a,info,iiy,jjy)
+  if(info /= psb_success_) then
+    info=psb_err_from_subroutine_
+    ch_err='psb_chkvect 2'
+    call psb_errpush(info,name,a_err=ch_err)
+    goto 9999
+  end if
+
+  if(desc_a%get_local_rows() > 0) then
+    call m%mask(c,x,t,info)
+  end if
+
+  call psb_erractionrestore(err_act)
+  return
+
+9999 call psb_error_handler(ictxt,err_act)
+
+  return
+
+end subroutine psb_smask_vect
+
+
diff --git a/base/psblas/psb_zcmp_vect.f90 b/base/psblas/psb_zcmp_vect.f90
index fa820d43..50d9bce5 100644
--- a/base/psblas/psb_zcmp_vect.f90
+++ b/base/psblas/psb_zcmp_vect.f90
@@ -103,3 +103,4 @@ subroutine psb_zcmp_vect(x,c,z,desc_a,info)
   return
 
 end subroutine psb_zcmp_vect
+
diff --git a/test/kernel/vecoperation.f90 b/test/kernel/vecoperation.f90
index 22dd56ae..330eeea1 100644
--- a/test/kernel/vecoperation.f90
+++ b/test/kernel/vecoperation.f90
@@ -57,6 +57,7 @@ program vecoperation
   character(len=20) :: name,ch_err,readinput
   real(psb_dpk_), allocatable :: vx(:), vy(:), vz(:)
   real(psb_dpk_) :: c
+  logical :: t
 
   info=psb_success_
 
@@ -225,6 +226,8 @@ program vecoperation
     write(psb_out_unit,'("z = ",es12.1)')vz(:)
   end if
 
+  call psb_mask(z,x,absz,t,desc_a,info)
+
   write(psb_out_unit,'("Computation of vector norms:")')
   norm1 = psb_norm1(x,desc_a,info)
   norm2 = psb_norm2(x,desc_a,info)