diff --git a/src/methd/psb_dbicg.f90 b/src/methd/psb_dbicg.f90
index f166e78b..62e58177 100644
--- a/src/methd/psb_dbicg.f90
+++ b/src/methd/psb_dbicg.f90
@@ -103,7 +103,7 @@ subroutine psb_dbicg(a,prec,b,x,eps,desc_a,info,&
   integer, pointer           :: iperm(:), ipnull(:), ipsave(:), int_err(:)
   real(kind(1.d0)) ::rerr
   integer       ::litmax, liter, naux, m, mglob, it, itrac,&
-       & nprows,npcols,me,mecol, n_row, n_col, listop, err_act
+       & nprows,npcols,me,mecol, n_row, n_col, istop_, err_act
   character     ::diagl, diagu
   logical, parameter :: debug = .false.
   logical, parameter :: exchange=.true., noexchange=.false.  
@@ -134,13 +134,13 @@ subroutine psb_dbicg(a,prec,b,x,eps,desc_a,info,&
 
 
   if (present(istop)) then 
-    listop = istop 
+    istop_ = istop 
   else
-    listop = 1
+    istop_ = 1
   endif
   !
-  !  listop = 1:  normwise backward error, infinity norm 
-  !  listop = 2:  ||r||/||b||   norm 2 
+  !  istop_ = 1:  normwise backward error, infinity norm 
+  !  istop_ = 2:  ||r||/||b||   norm 2 
   !
 !!$
 !!$  if ((prec%prec < min_prec_).or.(prec%prec > max_prec_) ) then
@@ -149,10 +149,10 @@ subroutine psb_dbicg(a,prec,b,x,eps,desc_a,info,&
 !!$    return
 !!$  endif
 
-  if ((listop < 1 ).or.(listop > 2 ) ) then
-    write(0,*) 'psb_bicg: invalid istop',listop 
+  if ((istop_ < 1 ).or.(istop_ > 2 ) ) then
+    write(0,*) 'psb_bicg: invalid istop',istop_ 
     info=5001
-    int_err=listop
+    int_err=istop_
     err=info
     call psb_errpush(info,name,i_err=int_err)
     goto 9999
@@ -197,10 +197,10 @@ subroutine psb_dbicg(a,prec,b,x,eps,desc_a,info,&
   diagu  = 'u'
   itx   = 0
   
-  if (listop == 1) then 
+  if (istop_ == 1) then 
      ani = psb_spnrmi(a,desc_a,info)
      bni = psb_geamax(b,desc_a,info)
-  else if (listop == 2) then 
+  else if (istop_ == 2) then 
      bn2 = psb_genrm2(b,desc_a,info)
   endif
  
@@ -228,10 +228,10 @@ subroutine psb_dbicg(a,prec,b,x,eps,desc_a,info,&
 
     rho = dzero
     if (debug) write(*,*) 'on entry to amax: b: ',size(b)
-    if (listop == 1) then 
+    if (istop_ == 1) then 
       rni = psb_geamax(r,desc_a,info)
       xni = psb_geamax(x,desc_a,info)
-    else if (listop == 2) then 
+    else if (istop_ == 2) then 
       rni = psb_genrm2(r,desc_a,info)
     endif
     if(info.ne.0) then
@@ -240,14 +240,14 @@ subroutine psb_dbicg(a,prec,b,x,eps,desc_a,info,&
        goto 9999
     end if
 
-    if (listop == 1) then 
+    if (istop_ == 1) then 
       xni  = psb_geamax(x,desc_a,info)
       rerr =  rni/(ani*xni+bni)
       if (itrac /= -1) then 
         if (me.eq.0) write(itrac,'(a,i4,5(2x,es10.4))') 'bicg: ',itx,rerr,rni,bni,&
              &xni,ani
       endif
-    else  if (listop == 2) then 
+    else  if (istop_ == 2) then 
       rerr = rni/bn2
       if (itrac /= -1) then 
         if (me.eq.0) write(itrac,'(a,i4,3(2x,es10.4))') 'bicg: ',itx,rerr,rni,bn2
@@ -307,21 +307,21 @@ subroutine psb_dbicg(a,prec,b,x,eps,desc_a,info,&
       call psb_geaxpby(-alpha,qt,done,rt,desc_a,info)
 
 
-      if (listop == 1) then 
+      if (istop_ == 1) then 
         rni = psb_geamax(r,desc_a,info)
         xni = psb_geamax(x,desc_a,info)
-      else if (listop == 2) then 
+      else if (istop_ == 2) then 
         rni = psb_genrm2(r,desc_a,info)
       endif
 
-      if (listop == 1) then 
+      if (istop_ == 1) then 
         xni  = psb_geamax(x,desc_a,info)
         rerr =  rni/(ani*xni+bni)
         if (itrac /= -1) then 
           if (me.eq.0) write(itrac,'(a,i4,5(2x,es10.4))') 'bicg: ',itx,rerr,rni,bni,&
                &xni,ani
         endif
-      else  if (listop == 2) then 
+      else  if (istop_  == 2) then 
         rerr = rni/bn2
         if (itrac /= -1) then 
           if (me.eq.0) write(itrac,'(a,i4,3(2x,es10.4))') 'bicg: ',itx,rerr,rni,bn2
diff --git a/src/methd/psb_dcg.f90 b/src/methd/psb_dcg.f90
index ee2973db..d78b1079 100644
--- a/src/methd/psb_dcg.f90
+++ b/src/methd/psb_dcg.f90
@@ -102,7 +102,7 @@ Subroutine psb_dcg(a,prec,b,x,eps,desc_a,info,&
   real(kind(1.d0))    ::rerr
   real(kind(1.d0))    ::alpha, beta, rho, rho_old, rni, xni, bni, ani,bn2,& 
        & sigma
-  integer         :: litmax, liter, listop, naux, m, mglob, it, itx, itrac,&
+  integer         :: litmax, liter, istop_, naux, m, mglob, it, itx, itrac,&
        & nprows,npcols,me,mecol, n_col, isvch, ich, icontxt, n_row,err_act, int_err(5)
   character          ::diagl, diagu
   logical, parameter :: exchange=.true., noexchange=.false.  
@@ -122,13 +122,13 @@ Subroutine psb_dcg(a,prec,b,x,eps,desc_a,info,&
 
 
   if (present(istop)) then 
-    listop = istop 
+    istop_ = istop 
   else
-    listop = 1
+    istop_ = 1
   endif
   !
-  !  LISTOP = 1:  Normwise backward error, infinity norm 
-  !  LISTOP = 2:  ||r||/||b||   norm 2 
+  !  ISTOP_ = 1:  Normwise backward error, infinity norm 
+  !  ISTOP_ = 2:  ||r||/||b||   norm 2 
   !
 
 !!$  If ((prec%prec < min_prec_).Or.(prec%prec > max_prec_) ) Then
@@ -137,10 +137,10 @@ Subroutine psb_dcg(a,prec,b,x,eps,desc_a,info,&
 !!$    Return
 !!$  Endif
 
-  if ((listop < 1 ).or.(listop > 2 ) ) then
-    write(0,*) 'psb_cg: invalid istop',listop 
+  if ((istop_ < 1 ).or.(istop_ > 2 ) ) then
+    write(0,*) 'psb_cg: invalid istop',istop_ 
     info=5001
-    int_err(1)=listop
+    int_err(1)=istop_
     err=info
     call psb_errpush(info,name,i_err=int_err)
     goto 9999
@@ -197,10 +197,10 @@ Subroutine psb_dcg(a,prec,b,x,eps,desc_a,info,&
     end if
 
     rho = dzero
-    if (listop == 1) then 
+    if (istop_ == 1) then 
       ani = psb_spnrmi(a,desc_a,info)
       bni = psb_geamax(b,desc_a,info)
-    else if (listop == 2) then 
+    else if (istop_ == 2) then 
       bn2 = psb_genrm2(b,desc_a,info)
     endif
     if (info.ne.0) then 
@@ -241,7 +241,7 @@ Subroutine psb_dcg(a,prec,b,x,eps,desc_a,info,&
       call psb_geaxpby(-alpha,q,done,r,desc_a,info)
 
 
-      if (listop == 1) Then 
+      if (istop_ == 1) Then 
         rni = psb_geamax(r,desc_a,info)
         xni = psb_geamax(x,desc_a,info)
         rerr =  rni/(ani*xni+bni)
@@ -250,7 +250,7 @@ Subroutine psb_dcg(a,prec,b,x,eps,desc_a,info,&
                &xni,ani
         Endif
 
-      Else  If (listop == 2) Then 
+      Else  If (istop_ == 2) Then 
 
         rni = psb_genrm2(r,desc_a,info)
         rerr = rni/bn2
diff --git a/src/methd/psb_dcgs.f90 b/src/methd/psb_dcgs.f90
index fc78a20c..9415dfef 100644
--- a/src/methd/psb_dcgs.f90
+++ b/src/methd/psb_dcgs.f90
@@ -101,7 +101,7 @@ Subroutine psb_dcgs(a,prec,b,x,eps,desc_a,info,&
   Integer, Pointer           :: iperm(:), ipnull(:), ipsave(:)
   Real(Kind(1.d0)) ::rerr
   Integer       ::litmax, liter, naux, m, mglob, it, itrac,int_err(5),&
-       & nprows,npcols,me,mecol, n_row, n_col,listop, err_act
+       & nprows,npcols,me,mecol, n_row, n_col,istop_, err_act
   Character     ::diagl, diagu
   Logical, Parameter :: exchange=.True., noexchange=.False.  
   Integer, Parameter :: irmax = 8
@@ -126,13 +126,13 @@ Subroutine psb_dcgs(a,prec,b,x,eps,desc_a,info,&
   n_col  = desc_a%matrix_data(psb_n_col_)
 
   If (Present(istop)) Then 
-    listop = istop 
+    istop_ = istop 
   Else
-    listop = 1
+    istop_ = 1
   Endif
 !
-!  listop = 1:  normwise backward error, infinity norm 
-!  listop = 2:  ||r||/||b||   norm 2 
+!  istop_ = 1:  normwise backward error, infinity norm 
+!  istop_ = 2:  ||r||/||b||   norm 2 
 !
 !!$
 !!$  If ((prec%prec < 0).Or.(prec%prec > 6) ) Then
@@ -141,10 +141,10 @@ Subroutine psb_dcgs(a,prec,b,x,eps,desc_a,info,&
 !!$     Return
 !!$  Endif
   
-  if ((listop < 1 ).or.(listop > 2 ) ) then
-    write(0,*) 'psb_cgs: invalid istop',listop 
+  if ((istop_ < 1 ).or.(istop_ > 2 ) ) then
+    write(0,*) 'psb_cgs: invalid istop',istop_ 
     info=5001
-    int_err=listop
+    int_err=istop_
     err=info
     call psb_errpush(info,name,i_err=int_err)
     goto 9999
@@ -195,10 +195,10 @@ Subroutine psb_dcgs(a,prec,b,x,eps,desc_a,info,&
   diagu  = 'u'
   itx   = 0
 
-  if (listop == 1) then 
+  if (istop_ == 1) then 
     ani = psb_spnrmi(a,desc_a,info)
     bni = psb_geamax(b,desc_a,info)
-  else if (listop == 2) then 
+  else if (istop_ == 2) then 
     bn2 = psb_genrm2(b,desc_a,info)
   endif
   if(info/=0)then
@@ -225,7 +225,7 @@ Subroutine psb_dcgs(a,prec,b,x,eps,desc_a,info,&
     rho = dzero
     If (debug) Write(*,*) 'on entry to amax: b: ',Size(b)
 
-    if (listop == 1) then 
+    if (istop_ == 1) then 
       rni = psb_geamax(r,desc_a,info)
       xni = psb_geamax(x,desc_a,info)
       rerr =  rni/(ani*xni+bni)
@@ -233,7 +233,7 @@ Subroutine psb_dcgs(a,prec,b,x,eps,desc_a,info,&
         If (me == 0) Write(itrac,'(a,i4,5(2x,es10.4))') 'cgs: ',&
              & itx,rerr,rni,bni,xni,ani
       endif
-    else if (listop == 2) then 
+    else if (istop_ == 2) then 
       rni = psb_genrm2(r,desc_a,info)
       rerr = rni/bn2
       if (itrac /= -1) then 
@@ -301,7 +301,7 @@ Subroutine psb_dcgs(a,prec,b,x,eps,desc_a,info,&
       Call psb_geaxpby(-alpha,qt,done,r,desc_a,info)
       
      
-      if (listop == 1) then 
+      if (istop_ == 1) then 
         rni = psb_geamax(r,desc_a,info)
         xni = psb_geamax(x,desc_a,info)
         rerr =  rni/(ani*xni+bni)
@@ -310,7 +310,7 @@ Subroutine psb_dcgs(a,prec,b,x,eps,desc_a,info,&
              & itx,rerr,rni,bni,xni,ani
         endif
 
-      else  if (listop == 2) then 
+      else  if (istop_ == 2) then 
 
         rni = psb_genrm2(r,desc_a,info)
         rerr = rni/bn2
diff --git a/src/methd/psb_dcgstab.f90 b/src/methd/psb_dcgstab.f90
index c39d31d0..055ef7de 100644
--- a/src/methd/psb_dcgstab.f90
+++ b/src/methd/psb_dcgstab.f90
@@ -107,7 +107,7 @@ Subroutine psb_dcgstab(a,prec,b,x,eps,desc_a,info,&
   Logical, Parameter :: exchange=.True., noexchange=.False., debug1 = .False.
   Integer, Parameter :: irmax = 8
   Integer            :: itx, i, isvch, ich, icontxt, err_act, int_err(5),ii
-  Integer            :: listop
+  Integer            :: istop_
   Logical            :: do_renum_left
   Real(Kind(1.d0)) :: alpha, beta, rho, rho_old, rni, xni, bni, ani,& 
        & sigma, omega, tau, rn0, bn2
@@ -129,28 +129,28 @@ Subroutine psb_dcgstab(a,prec,b,x,eps,desc_a,info,&
   n_col = desc_a%matrix_data(psb_n_col_)
 
   If (Present(istop)) Then 
-    listop = istop 
+    istop_ = istop 
   Else
-    listop = 1
+    istop_ = 1
   Endif
 !
-!  LISTOP = 1:  Normwise backward error, infinity norm 
-!  LISTOP = 2:  ||r||/||b||   norm 2 
+!  ISTOP_ = 1:  Normwise backward error, infinity norm 
+!  ISTOP_ = 2:  ||r||/||b||   norm 2 
 !
 
-  If ((prec%prec < min_prec_).Or.(prec%prec > max_prec_) ) Then
-     Write(0,*) 'PSB_CGSTAB: Invalid IPREC',prec%prec
-     info=5002
-     int_err(1)=prec%prec
-     err=info
-     call psb_errpush(info,name,i_err=int_err)
-     goto 9999
-  Endif
+!!$  If ((prec%prec < min_prec_).Or.(prec%prec > max_prec_) ) Then
+!!$     Write(0,*) 'PSB_CGSTAB: Invalid IPREC',prec%prec
+!!$     info=5002
+!!$     int_err(1)=prec%prec
+!!$     err=info
+!!$     call psb_errpush(info,name,i_err=int_err)
+!!$     goto 9999
+!!$  Endif
   
-  if ((listop < 1 ).or.(listop > 2 ) ) then
-    write(0,*) 'psb_bicgstab: invalid istop',listop 
+  if ((istop_ < 1 ).or.(istop_ > 2 ) ) then
+    write(0,*) 'psb_bicgstab: invalid istop',istop_ 
     info=5001
-    int_err(1)=listop
+    int_err(1)=istop_
     err=info
     call psb_errpush(info,name,i_err=int_err)
     goto 9999
@@ -197,10 +197,10 @@ Subroutine psb_dcgstab(a,prec,b,x,eps,desc_a,info,&
 
   itx   = 0
 
-  If (listop == 1) Then 
+  If (istop_ == 1) Then 
     ani = psb_spnrmi(a,desc_a,info)
     bni = psb_geamax(b,desc_a,info)
-  Else If (listop == 2) Then 
+  Else If (istop_ == 2) Then 
     bn2 = psb_genrm2(b,desc_a,info)
   Endif
   if (info /= 0) Then 
@@ -231,10 +231,10 @@ Subroutine psb_dcgstab(a,prec,b,x,eps,desc_a,info,&
 !   Must always provide norm of R into RNI below for first check on 
 !   residual
 !
-    If (listop == 1) Then 
+    If (istop_ == 1) Then 
       rni = psb_geamax(r,desc_a,info)
       xni = psb_geamax(x,desc_a,info)
-    Else If (listop == 2) Then 
+    Else If (istop_ == 2) Then 
       rni = psb_genrm2(r,desc_a,info)
     Endif
     if (info /= 0) Then 
@@ -253,14 +253,14 @@ Subroutine psb_dcgstab(a,prec,b,x,eps,desc_a,info,&
       Exit restart
     End If
     
-    If (listop == 1) Then 
+    If (istop_ == 1) Then 
       xni  = psb_geamax(x,desc_a,info)
       rerr =  rni/(ani*xni+bni)
       If (itrac /= -1) Then 
         If (myrow == 0) Write(itrac,'(a,i4,5(2x,es10.4))') 'bicgstab: ',itx,rerr,rni,bni,&
              &xni,ani
       Endif
-    Else  If (listop == 2) Then 
+    Else  If (istop_ == 2) Then 
       rerr = rni/bn2
       If (itrac /= -1) Then 
         If (myrow == 0) Write(itrac,'(a,i4,3(2x,es10.4))') 'bicgstab: ',itx,rerr,rni,bn2
@@ -355,7 +355,7 @@ Subroutine psb_dcgstab(a,prec,b,x,eps,desc_a,info,&
       Call psb_geaxpby(done,s,dzero,r,desc_a,info)
       Call psb_geaxpby(-omega,t,done,r,desc_a,info)
       
-      If (listop == 1) Then 
+      If (istop_ == 1) Then 
         rni = psb_geamax(r,desc_a,info)
         xni = psb_geamax(x,desc_a,info)
         rerr =  rni/(ani*xni+bni)
@@ -364,7 +364,7 @@ Subroutine psb_dcgstab(a,prec,b,x,eps,desc_a,info,&
                & 'bicgstab: ',itx,rerr,rni,bni,xni,ani
         Endif
 
-      Else  If (listop == 2) Then 
+      Else  If (istop_ == 2) Then 
         rni = psb_genrm2(r,desc_a,info)
         rerr = rni/bn2
         If (itrac /= -1) Then 
diff --git a/src/methd/psb_dcgstabl.f90 b/src/methd/psb_dcgstabl.f90
index 42de7626..150ba426 100644
--- a/src/methd/psb_dcgstabl.f90
+++ b/src/methd/psb_dcgstabl.f90
@@ -114,7 +114,7 @@ Subroutine psb_dcgstabl(a,prec,b,x,eps,desc_a,info,&
   Character     ::diagl, diagu
   Logical, Parameter :: exchange=.True., noexchange=.False.  
   Integer, Parameter :: irmax = 8
-  Integer            :: itx, i, isvch, ich, icontxt,listop,j, int_err(5)
+  Integer            :: itx, i, isvch, ich, icontxt,istop_,j, int_err(5)
   Logical            :: do_renum_left
   Logical, Parameter :: debug = .False.
   Real(Kind(1.d0)) :: alpha, beta, rho, rho_old, rni, xni, bni, ani,bn2,& 
@@ -136,19 +136,19 @@ Subroutine psb_dcgstabl(a,prec,b,x,eps,desc_a,info,&
   n_col = desc_a%matrix_data(psb_n_col_)
 
   if (present(istop)) then 
-    listop = istop 
+    istop_ = istop 
   else
-    listop = 1
+    istop_ = 1
   endif
 !
-!  LISTOP = 1:  Normwise backward error, infinity norm 
-!  LISTOP = 2:  ||r||/||b||   norm 2 
+!  ISTOP_ = 1:  Normwise backward error, infinity norm 
+!  ISTOP_ = 2:  ||r||/||b||   norm 2 
 !
 
-  if ((listop < 1 ).or.(listop > 2 ) ) then
-    write(0,*) 'psb_bicgstabl: invalid istop',listop 
+  if ((istop_ < 1 ).or.(istop_ > 2 ) ) then
+    write(0,*) 'psb_bicgstabl: invalid istop',istop_ 
     info=5001
-    int_err=listop
+    int_err=istop_
     err=info
     call psb_errpush(info,name,i_err=int_err)
     goto 9999
@@ -211,10 +211,10 @@ Subroutine psb_dcgstabl(a,prec,b,x,eps,desc_a,info,&
   ich = 1 
   Call blacs_set(icontxt,16,ich)
 
-  if (listop == 1) then 
+  if (istop_ == 1) then 
     ani = psb_spnrmi(a,desc_a,info)
     bni = psb_geamax(b,desc_a,info)
-  else if (listop == 2) then 
+  else if (istop_ == 2) then 
     bn2 = psb_genrm2(b,desc_a,info)
   endif
   if (info.ne.0) Then 
@@ -253,7 +253,7 @@ Subroutine psb_dcgstabl(a,prec,b,x,eps,desc_a,info,&
 
     If (debug) Write(0,*) 'on entry to amax: b: ',Size(b)
 
-    if (listop == 1) then 
+    if (istop_ == 1) then 
       rni = psb_geamax(r,desc_a,info)
       xni = psb_geamax(x,desc_a,info)
       rerr =  rni/(ani*xni+bni)
@@ -261,7 +261,7 @@ Subroutine psb_dcgstabl(a,prec,b,x,eps,desc_a,info,&
           If (me == 0) Write(itrac,'(a,i4,5(2x,es10.4))') 'bicgstab(l): ',&
                & itx,rerr,rni,bni,xni,ani
       endif
-    else if (listop == 2) then 
+    else if (istop_ == 2) then 
       rni = psb_genrm2(r,desc_a,info)
       rerr = rni/bn2
       if (itrac /= -1) then  
@@ -362,7 +362,7 @@ Subroutine psb_dcgstabl(a,prec,b,x,eps,desc_a,info,&
         Call psb_geaxpby(-gamma1(j),rh(:,j),done,rh(:,0),desc_a,info)        
       Enddo
       
-      if (listop == 1) then 
+      if (istop_ == 1) then 
         rni = psb_geamax(rh(:,0),desc_a,info)
         xni = psb_geamax(x,desc_a,info)
         rerr =  rni/(ani*xni+bni)
@@ -371,7 +371,7 @@ Subroutine psb_dcgstabl(a,prec,b,x,eps,desc_a,info,&
                & itx,rerr,rni,bni,xni,ani
         endif
 
-      else  if (listop == 2) then 
+      else  if (istop_ == 2) then 
 
         rni = psb_genrm2(rh(:,0),desc_a,info)
         rerr = rni/bn2
diff --git a/src/methd/psb_dgmresr.f90 b/src/methd/psb_dgmresr.f90
index 8ce6d367..0b9f0f27 100644
--- a/src/methd/psb_dgmresr.f90
+++ b/src/methd/psb_dgmresr.f90
@@ -116,7 +116,7 @@ Subroutine psb_dgmresr(a,prec,b,x,eps,desc_a,info,&
   Character     ::diagl, diagu
   Logical, Parameter :: exchange=.True., noexchange=.False.  
   Integer, Parameter :: irmax = 8
-  Integer            :: itx, i, isvch, ich, icontxt,listop, err_act
+  Integer            :: itx, i, isvch, ich, icontxt,istop_, err_act
   Logical            :: do_renum_left,inner_stop
   Logical, Parameter :: debug = .false.
   Real(Kind(1.d0)) :: alpha, beta, rho, rho_old, rni, xni, bni, ani,bn2,& 
@@ -139,19 +139,19 @@ Subroutine psb_dgmresr(a,prec,b,x,eps,desc_a,info,&
   n_col = desc_a%matrix_data(psb_n_col_)
 
   if (present(istop)) then 
-    listop = istop 
+    istop_ = istop 
   else
-    listop = 1
+    istop_ = 1
   endif
 !
-!  LISTOP = 1:  Normwise backward error, infinity norm 
-!  LISTOP = 2:  ||r||/||b||   norm 2 
+!  ISTOP_ = 1:  Normwise backward error, infinity norm 
+!  ISTOP_ = 2:  ||r||/||b||   norm 2 
 !
 
-  if ((listop < 1 ).or.(listop > 2 ) ) then
-    write(0,*) 'psb_dgmres: invalid istop',listop 
+  if ((istop_ < 1 ).or.(istop_ > 2 ) ) then
+    write(0,*) 'psb_dgmres: invalid istop',istop_ 
     info=5001
-    int_err(1)=listop
+    int_err(1)=istop_
     err=info
     call psb_errpush(info,name,i_err=int_err)
     goto 9999
@@ -204,10 +204,10 @@ Subroutine psb_dgmresr(a,prec,b,x,eps,desc_a,info,&
   ich = 1 
   Call blacs_set(icontxt,16,ich)
 
-  if (listop == 1) then 
+  if (istop_ == 1) then 
     ani = psb_spnrmi(a,desc_a,info)
     bni = psb_geamax(b,desc_a,info)
-  else if (listop == 2) then 
+  else if (istop_ == 2) then 
     bn2 = psb_genrm2(b,desc_a,info)
   endif
   if (info.ne.0) Then 
@@ -244,7 +244,7 @@ Subroutine psb_dgmresr(a,prec,b,x,eps,desc_a,info,&
     scal=done/rs(1)
     If (debug) Write(0,*) 'on entry to amax: b: ',Size(b),rs(1),scal
 
-    if (listop == 1) then 
+    if (istop_ == 1) then 
       rni = psb_geamax(v(:,1),desc_a,info)
       xni = psb_geamax(x,desc_a,info)
       rerr =  rni/(ani*xni+bni)
@@ -252,7 +252,7 @@ Subroutine psb_dgmresr(a,prec,b,x,eps,desc_a,info,&
           If (me == 0) Write(itrac,'(a,i4,5(2x,es10.4))') 'gmresr(l): ',&
                & itx,rerr,rni,bni,xni,ani
       endif
-    else if (listop == 2) then 
+    else if (istop_ == 2) then 
       rni = psb_genrm2(v(:,1),desc_a,info)
       rerr = rni/bn2
       if (itrac /= -1) then  
@@ -301,7 +301,7 @@ Subroutine psb_dgmresr(a,prec,b,x,eps,desc_a,info,&
       rs(i)   = c(i)*rs(i)
       rr(i,i)  = c(i)*h(i,i)+s(i)*h(i+1,i)
             
-      if (listop == 1) then 
+      if (istop_ == 1) then 
         rni = abs(rs(i+1))
         xni = psb_geamax(x,desc_a,info)
         rerr =  rni/(ani*xni+bni)
@@ -309,7 +309,7 @@ Subroutine psb_dgmresr(a,prec,b,x,eps,desc_a,info,&
           If (me == 0) Write(itrac,'(a,i4,5(2x,es10.4))') 'gmresr(l): ',&
                & itx,rerr,rni,bni,xni,ani
         endif
-      else if (listop == 2) then 
+      else if (istop_ == 2) then 
         rni = abs(rs(i+1))
         rerr = rni/bn2
         if (itrac /= -1) then  
diff --git a/src/methd/psb_zcgs.f90 b/src/methd/psb_zcgs.f90
index 7c979c7b..e6ce8489 100644
--- a/src/methd/psb_zcgs.f90
+++ b/src/methd/psb_zcgs.f90
@@ -101,7 +101,7 @@ Subroutine psb_zcgs(a,prec,b,x,eps,desc_a,info,&
   Integer, Pointer           :: iperm(:), ipnull(:), ipsave(:)
   Real(Kind(1.d0)) ::rerr
   Integer       ::litmax, liter, naux, m, mglob, it, itrac,int_err(5),&
-       & nprows,npcols,me,mecol, n_row, n_col,listop, err_act
+       & nprows,npcols,me,mecol, n_row, n_col,istop_, err_act
   Character     ::diagl, diagu
   Logical, Parameter :: exchange=.True., noexchange=.False.  
   Integer, Parameter :: irmax = 8
@@ -126,13 +126,13 @@ Subroutine psb_zcgs(a,prec,b,x,eps,desc_a,info,&
   n_col  = desc_a%matrix_data(psb_n_col_)
 
   If (Present(istop)) Then 
-    listop = istop 
+    istop_ = istop 
   Else
-    listop = 1
+    istop_ = 1
   Endif
 !
-!  listop = 1:  normwise backward error, infinity norm 
-!  listop = 2:  ||r||/||b||   norm 2 
+!  istop_ = 1:  normwise backward error, infinity norm 
+!  istop_ = 2:  ||r||/||b||   norm 2 
 !
 !!$
 !!$  If ((prec%prec < 0).Or.(prec%prec > 6) ) Then
@@ -141,10 +141,10 @@ Subroutine psb_zcgs(a,prec,b,x,eps,desc_a,info,&
 !!$     Return
 !!$  Endif
   
-  if ((listop < 1 ).or.(listop > 2 ) ) then
-    write(0,*) 'psb_cgs: invalid istop',listop 
+  if ((istop_ < 1 ).or.(istop_ > 2 ) ) then
+    write(0,*) 'psb_cgs: invalid istop',istop_ 
     info=5001
-    int_err=listop
+    int_err=istop_
     err=info
     call psb_errpush(info,name,i_err=int_err)
     goto 9999
@@ -195,10 +195,10 @@ Subroutine psb_zcgs(a,prec,b,x,eps,desc_a,info,&
   diagu  = 'u'
   itx   = 0
 
-  if (listop == 1) then 
+  if (istop_ == 1) then 
     ani = psb_spnrmi(a,desc_a,info)
     bni = psb_geamax(b,desc_a,info)
-  else if (listop == 2) then 
+  else if (istop_ == 2) then 
     bn2 = psb_genrm2(b,desc_a,info)
   endif
   if(info/=0)then
@@ -225,7 +225,7 @@ Subroutine psb_zcgs(a,prec,b,x,eps,desc_a,info,&
     rho = zzero
     If (debug) Write(*,*) 'on entry to amax: b: ',Size(b)
 
-    if (listop == 1) then 
+    if (istop_ == 1) then 
       rni = psb_geamax(r,desc_a,info)
       xni = psb_geamax(x,desc_a,info)
       rerr =  rni/(ani*xni+bni)
@@ -233,7 +233,7 @@ Subroutine psb_zcgs(a,prec,b,x,eps,desc_a,info,&
         If (me == 0) Write(itrac,'(a,i4,5(2x,es10.4))') 'cgs: ',&
              & itx,rerr,rni,bni,xni,ani
       endif
-    else if (listop == 2) then 
+    else if (istop_ == 2) then 
       rni = psb_genrm2(r,desc_a,info)
       rerr = rni/bn2
       if (itrac /= -1) then 
@@ -301,7 +301,7 @@ Subroutine psb_zcgs(a,prec,b,x,eps,desc_a,info,&
       Call psb_geaxpby(-alpha,qt,zone,r,desc_a,info)
       
      
-      if (listop == 1) then 
+      if (istop_ == 1) then 
         rni = psb_geamax(r,desc_a,info)
         xni = psb_geamax(x,desc_a,info)
         rerr =  rni/(ani*xni+bni)
@@ -310,7 +310,7 @@ Subroutine psb_zcgs(a,prec,b,x,eps,desc_a,info,&
              & itx,rerr,rni,bni,xni,ani
         endif
 
-      else  if (listop == 2) then 
+      else  if (istop_ == 2) then 
 
         rni = psb_genrm2(r,desc_a,info)
         rerr = rni/bn2
diff --git a/src/methd/psb_zcgstab.f90 b/src/methd/psb_zcgstab.f90
index e394a37b..5c134576 100644
--- a/src/methd/psb_zcgstab.f90
+++ b/src/methd/psb_zcgstab.f90
@@ -107,7 +107,7 @@ Subroutine psb_zcgstab(a,prec,b,x,eps,desc_a,info,&
   Logical, Parameter :: exchange=.True., noexchange=.False., debug1 = .False.
   Integer, Parameter :: irmax = 8
   Integer            :: itx, i, isvch, ich, icontxt, err_act, int_err(5),ii
-  Integer            :: listop
+  Integer            :: istop_
   Logical            :: do_renum_left
   complex(Kind(1.d0)) :: alpha, beta, rho, rho_old, sigma, omega, tau
   Real(Kind(1.d0)) :: rni, xni, bni, ani, rn0, bn2
@@ -129,28 +129,28 @@ Subroutine psb_zcgstab(a,prec,b,x,eps,desc_a,info,&
   n_col = desc_a%matrix_data(psb_n_col_)
 
   If (Present(istop)) Then 
-    listop = istop 
+    istop_ = istop 
   Else
-    listop = 1
+    istop_ = 1
   Endif
 !
-!  LISTOP = 1:  Normwise backward error, infinity norm 
-!  LISTOP = 2:  ||r||/||b||   norm 2 
+!  ISTOP_ = 1:  Normwise backward error, infinity norm 
+!  ISTOP_ = 2:  ||r||/||b||   norm 2 
 !
-
-  If ((prec%prec < min_prec_).Or.(prec%prec > max_prec_) ) Then
-     Write(0,*) 'PSB_CGSTAB: Invalid IPREC',prec%prec
-     info=5002
-     int_err(1)=prec%prec
-     err=info
-     call psb_errpush(info,name,i_err=int_err)
-     goto 9999
-  Endif
+!!$
+!!$  If ((prec%prec < min_prec_).Or.(prec%prec > max_prec_) ) Then
+!!$     Write(0,*) 'PSB_CGSTAB: Invalid IPREC',prec%prec
+!!$     info=5002
+!!$     int_err(1)=prec%prec
+!!$     err=info
+!!$     call psb_errpush(info,name,i_err=int_err)
+!!$     goto 9999
+!!$  Endif
   
-  if ((listop < 1 ).or.(listop > 2 ) ) then
-    write(0,*) 'psb_bicgstab: invalid istop',listop 
+  if ((istop_ < 1 ).or.(istop_ > 2 ) ) then
+    write(0,*) 'psb_bicgstab: invalid istop',istop_ 
     info=5001
-    int_err(1)=listop
+    int_err(1)=istop_
     err=info
     call psb_errpush(info,name,i_err=int_err)
     goto 9999
@@ -197,10 +197,10 @@ Subroutine psb_zcgstab(a,prec,b,x,eps,desc_a,info,&
 
   itx   = 0
 
-  If (listop == 1) Then 
+  If (istop_ == 1) Then 
     ani = psb_spnrmi(a,desc_a,info)
     bni = psb_geamax(b,desc_a,info)
-  Else If (listop == 2) Then 
+  Else If (istop_ == 2) Then 
     bn2 = psb_genrm2(b,desc_a,info)
   Endif
   if (info /= 0) Then 
@@ -231,10 +231,10 @@ Subroutine psb_zcgstab(a,prec,b,x,eps,desc_a,info,&
 !   Must always provide norm of R into RNI below for first check on 
 !   residual
 !
-    If (listop == 1) Then 
+    If (istop_ == 1) Then 
       rni = psb_geamax(r,desc_a,info)
       xni = psb_geamax(x,desc_a,info)
-    Else If (listop == 2) Then 
+    Else If (istop_ == 2) Then 
       rni = psb_genrm2(r,desc_a,info)
     Endif
     if (info /= 0) Then 
@@ -253,14 +253,14 @@ Subroutine psb_zcgstab(a,prec,b,x,eps,desc_a,info,&
       Exit restart
     End If
     
-    If (listop == 1) Then 
+    If (istop_ == 1) Then 
       xni  = psb_geamax(x,desc_a,info)
       rerr =  rni/(ani*xni+bni)
       If (itrac /= -1) Then 
         If (myrow == 0) Write(itrac,'(a,i4,5(2x,es10.4))') 'bicgstab: ',itx,rerr,rni,bni,&
              &xni,ani
       Endif
-    Else  If (listop == 2) Then 
+    Else  If (istop_ == 2) Then 
       rerr = rni/bn2
       If (itrac /= -1) Then 
         If (myrow == 0) Write(itrac,'(a,i4,3(2x,es10.4))') 'bicgstab: ',itx,rerr,rni,bn2
@@ -354,7 +354,7 @@ Subroutine psb_zcgstab(a,prec,b,x,eps,desc_a,info,&
       Call psb_geaxpby(zone,s,zzero,r,desc_a,info)
       Call psb_geaxpby(-omega,t,zone,r,desc_a,info)
       
-      If (listop == 1) Then 
+      If (istop_ == 1) Then 
         rni = psb_geamax(r,desc_a,info)
         xni = psb_geamax(x,desc_a,info)
         rerr =  rni/(ani*xni+bni)
@@ -363,7 +363,7 @@ Subroutine psb_zcgstab(a,prec,b,x,eps,desc_a,info,&
                & 'bicgstab: ',itx,rerr,rni,bni,xni,ani
         Endif
 
-      Else  If (listop == 2) Then 
+      Else  If (istop_ == 2) Then 
         rni = psb_genrm2(r,desc_a,info)
         rerr = rni/bn2
         If (itrac /= -1) Then