psblas3

base/serial/README.serial
 base/serial/psi_serial_impl.f90

Obsolete README. 
Added comment to serial_impl.

base/serial/README.serial

@@ -1,65 +0,0 @@
-Most of the subdirectories here contain material that was originally
-distributed through the serial sparse blas SPARKER project, plus a
-number of extensions of our own design. The original file spblas.f can
-be downloaded from matisa.cc.rl.ac.uk; of course any bugs in our 
-implementation are our own to fix.  
-
-The main reference for the serial
-sparse BLAS is: 
-Duff, I., Marrone, M., Radicati, G., and Vittoli, C.
-Level 3 basic linear algebra subprograms for sparse matrices: a user 
-level interface
-ACM Trans. Math. Softw., 23(3), 379-401, 1997.
-
-We also include  SMMP by Randolph E. Bank and
-Craig C. Douglas  na.bank@na-net.ornl.gov and
-na.cdouglas@na-net.ornl.gov;  we wrapped  it in a Fortran 95 interface
-with dynamic memory allocation. 
-
-
-
-How do you add a new storage format? Here is your checklist. 
-1.  You have to invent a name for it, a name that can fit into 3
-    letters.
-2.  You have to decide whether you need fields into INFOA() for it, and
-    invent their names/positions accordingly.
-3.  You have to add an estimate (as good as possible) for the memory
-    occupation into psb_cest.
-4.  You have to be able to generate it. For our purposes, the minimum
-    effort that still meets the requirements is the ability to convert
-    to/from COOrdinate; the relevant code (properly encapsulated in
-    subroutines) should be added into psb_spcnv; you can take Xcocr as
-    the model. You may or may not be able to do it "in place";
-    ipcoo2csr & friends do just that; if you can, please add it because
-    it may come in handy.
-5.  If you need to sort entries, it usually better to use imsrx than
-    isrx. This is because coefficients lists are likely to contain
-    multiple ordered sublists ("runs"), and the merge sort algorithm
-    implemented in imsrx is capable of taking advantage of them,
-    whereas the isrx quicksort cannot. 
-6.  You have to be able to convert it back to COOrdinate. This is
-    usually not hard, because the code that does the MV multiply is
-    already (maybe implicitly) walking through the coefficients while
-    keeping track of both row and column index, thus it suffices to
-    copy them as you meet them, and then call psb_fixcoo (which sorts
-    and compacts the output) on the result. 
-7.  You have to embed the MV and SV codes in the infrastructure; this
-    is done first in the xSWMM and xSWSM routines that do a select on
-    the FIDA value. Below this level you're free to do as you please. 
-8.  You have to extend the output capability of psb_Xcsprt. Again this
-    is  easy for the same reasons as in 6. 
-9.  You have to extend psb_Xcsrws for DIAG preconditioner. 
-10. Provide an UPDATE functionality, and add it to psb_update_mod;
-    currently JAD is out of this. 
-11. You have to provide the query facilities used in PSB_XSPINFO
-    (included  in base/modules/psb_spmat_type). 
-12. You have to provide the functionality to extract a block of
-    rows in psb_getrow_mod.f90. This is used in the GETROW/GETBLK/CLIP
-    chain; GETROW is (all that is) used by the ILU factorization. 
-13. You have to provide the GETDIAG functionality. 
-14. RWEXTD: what do we do here? Should we switch to/from COO?????
-    The current interface is ugly! 
-15. CSC is currently a second class citizen; it is only needed for
-    interfacing UMFPACK in the mld2p4 preconditioners. 
-
-Is this complete? I sure hope so.... 

base/serial/psi_serial_impl.f90

@@ -29,6 +29,17 @@
 !!$  POSSIBILITY OF SUCH DAMAGE.
 !!$ 
 !!$  
+!
+! Gather/scatter routines for implementing halo/ovrl communication. 
+!
+!  
+!
+! Gather: Y = beta * Y + alpha * X(IDX(:))
+!
+!
+! Scatter: 
+! Y(IDX(:)) = beta*Y(IDX(:)) + X(:)
+!
 subroutine psi_igthv(n,idx,alpha,x,beta,y)
 
   use psb_const_mod