logs from the modifications from scalapack-1.7.0 to scalapack-1.7.4

********************************************************************************
From Rev:1 to Rev:12

    M SRC/Makefile
    M SRC/pslared1d.f
    M SRC/pdlared1d.f
    M SRC/pslared2d.f
    M SRC/pdlared2d.f
    M SRC/pcgesv.f
    M SRC/psgesv.f
    M SRC/pdgesv.f
    M SRC/pzgesv.f
    M SRC/pslahqr.f
    M SRC/pclahqr.f
    M SRC/pdlahqr.f
    M SRC/pzlahqr.f
    M SRC/pzgesvd.f
    M SRC/pcgesvd.f
    M SRC/psgesvd.f
    M SRC/pdgesvd.f
    M PBLAS/SRC/PBtools.h
    M PBLAS/SRC/pblas.h
    M SRC/psdbtrf.f
    M SRC/pcheevd.f
    M SRC/pzheevd.f
    M SRC/pcheevx.f
    M SRC/pzheevx.f
    M SRC/pchegvx.f
    M SRC/pzhegvx.f
    M SRC/pdsygvx.f
    M SRC/pssyevx.f
    M SRC/pssygvx.f
    M SRC/pdsyevx.f
    M SRC/pcgetri.f
    M SRC/pdgetri.f
    M SRC/psgetri.f
    M SRC/pzgetri.f
    M TESTING/EIG/pcseptst.f
    M TESTING/EIG/pzseptst.f
    M TESTING/LIN/pcinvdriver.f
    M TESTING/LIN/pdinvdriver.f
    M TESTING/LIN/psinvdriver.f
    M TESTING/LIN/pzinvdriver.f

********************************************************************************

r12 
Last Modification: langou - Wed, 10 May 2006


Following up on r11. In r11, we have increased the size of the integer
workspace in the rectangular case.  We now report the new integer block size
calculation in the tester. So that the LIWORK given by the tester to the
PxGETRI is big enough ...

********************************************************************************

r11
Last Modification: langou - Wed, 10 May 2006

-------------------------------------------------------------
Correct the integer workspace (IWORK) calculation in PxGETRI.
-------------------------------------------------------------

Bug report send by Desheng Wang from Caltech on scalapack@cs.utk.edu, Mon, 1
May 2006.

Fix:
Replace the line 221-222:

               LIWMIN = NQ + MAX( ICEIL( ICEIL( MP, DESCA( MB_ ) ),
     $                            LCM / NPROW ), DESCA( NB_ ) ) 

By:
               LIWMIN = NUMROC( DESCA( M_ ) + DESCA( MB_ ) * NPROW
     $                  + MOD ( IA - 1, DESCA( MB_ ) ), DESCA ( NB_ ),
     $                  MYCOL, DESCA( CSRC_ ), NPCOL ) +
     $                  MAX ( DESCA( MB_ ) * ICEIL ( ICEIL(
     $                  NUMROC( DESCA( M_ ) + DESCA( MB_ ) * NPROW,
     $                  DESCA( MB_ ), MYROW, DESCA( RSRC_ ), NPROW ),
     $                  DESCA( MB_ ) ), LCM / NPROW ), DESCA( NB_ ) )

Yep, slightly more complex...

The error in the first computation is that it misinterpret the statement in
PxLAPIV: The formula for the integer worskpace calculation in PxLAPIV is

   LDW = LOCc( M_P + MOD(IP-1, MB_P) ) +
         MB_P * CEIL( CEIL(LOCr(M_P)/MB_P) / (LCM/NPROW) )

where M_P is the local size of the IPIV. But the IPIV is slighlty bigger than A, 
the global size of IPIV is:
           MP = DESCA( M_ ) + DESCA( MB_ ) * NPROW
(and not DESCA(M_)).

The other quantities are given by

   M_P     is the global length of the pivot vector
           MP = DESCA( M_ ) + DESCA( MB_ ) * NPROW
   I_P     is IA
           I_P = IA
   MB_P    is the block size use for the block cyclic distribution of the 
           pivot vector
           MB_P = DESCA (MB_ )
   LOCc ( . ) 
           NUMROC ( . , DESCA ( NB_ ), MYCOL, DESCA ( CSRC_ ), NPCOL )
   LOCr ( . )
           NUMROC ( . , DESCA ( MB_ ), MYROW, DESCA ( RSRC_ ), NPROW )
   CEIL ( X / Y )
           ICEIL( X, Y )
   LCM 
           LCM = ILCM( NPROW, NPCOL )

and this gives the new formula to compute the integer workspace.

********************************************************************************

Rev: 10
Last modification: langou - Wed, 22 Mar 2006

Bug report from Yasuhiro Nakahara (Canon inc.) on 03/13/2006:

  Description: pzlahqr routine was aborted due to a segmentation fault.
  I found an invalid memory access at the line 525 in pzlahqr.f.
  In the DO-loop, with II=1, S1(1, 0) was accessed.

Patch from Greg Henry (Intel) and Mark Fahey (ORNL)

Greg said:
> There is an easy fix for this- the idea of exceptional shifts is
> to just try something outside the norm based on the size of the diagonal
> elements.  The offending part can be removed from the code without a
> loss of generality.  I think I may be able to come with an alternate
> solution.


move from
---------------------------------------------------------------
*
*           Exceptional shift.
*
            DO 20 II = 2*JBLK, 1, -1
               S1( II, II ) = CONST*( CABS1( S1( II, II ) )+
     $                        CABS1( S1( II, II-1 ) ) )
               S1( II, II-1 ) = ZERO
               S1( II-1, II ) = ZERO
   20       CONTINUE
---------------------------------------------------------------
   (with problem when II=1 ...)
to
---------------------------------------------------------------
*
*           Exceptional shift.
*
            DO 20 II = 2*JBLK, 2, -1
               S1( II, II ) = CONST*( CABS1( S1( II, II ) )+
     $                        CABS1( S1( II, II-1 ) ) )
               S1( II, II-1 ) = ZERO
               S1( II-1, II ) = ZERO
   20       CONTINUE
            S1( 1, 1 ) = CONST*CABS1( S1( 1, 1 ) )
---------------------------------------------------------------

Note that this part of the code is not exercized by the testing.
(So the bug was hard to find.)



********************************************************************************

Rev: 9  
Last modification: julie - Thu, 23 Feb 2006 

Correct typo in the [S,D,C,Z]gesvd files for the delaclaration of WP[S,D,C,Z]ORMBRQLN 

********************************************************************************

Rev: 8 
Last modification: julie - Wed, 22 Feb 2006

Modify typo in comment + description of workspace.
When RANGE='V', work need to be of dimension 3 


********************************************************************************

Rev: 7 
Last modification: julie - Mon, 20 Feb 2006

Correction of a Typo mistake in the work comment.

********************************************************************************

Rev: 6 
Last modification: julie - Wed, 01 Feb 2006

Modify the makefile to add the two new driver: pcgesvd.f and pzgesvd.f  

********************************************************************************

Rev: 5
Last modification: Rev 5 - langou - 2006-01-31 05:13:22
Log message:
M SRC/psgesvd.f
M SRC/pcgesvd.f
M SRC/pzgesvd.f
M SRC/pdgesvd.f

modify the workspace size of xBDSQR to follow the revision 184 of LAPACK the
workspace size of xBDSQR has moved from
* WDBDSQR = MAX(1, 4*SIZE )
to
* WDBDSQR = MAX(1, 2*SIZE + (2*SIZE - 4)*MAX(WANTU, WANTVT))
and is now back to
* WDBDSQR = MAX(1, 4*SIZE )
so SVD of ScaLAPACK is following (at least let us take the max of both until
LAPACK is fixed on its workspace size)

********************************************************************************

Rev: 4
Last modification: Rev 4 - langou - 2006-01-31 04:52:48
Log message:
M SRC/pslahrd.f
M SRC/pdlahqr.f
(forgot to change the date in the header in the last revision, corrected)

M SRC/psgesvd.f
M SRC/pdgesvd.f
[Julien/Osni]
correct a bug in the workspace utilisation of p_gesvd. In the case jobU='V' and
jobVT='V', the routine has good pointers, otherwise the pointers in the
workspace where shifted as if matrices U and VT existed which implied out of
bound reference for the value stored at the end of the workspace.  There was
also a few problems at the end of the code with some sizes in the case of
rectangular matrices.

A SRC/pcgesvd.f
A SRC/pzgesvd.f
add the complex version of the SVD driver contributed code by Peng Du (Graduate
Research Assistant at UTK, Fall 2005) supervised by Julien

********************************************************************************

Rev: 3 
Last modification: Rev 3 - langou - 2006-01-30 17:35:23
Log message:
SRC/p[s,d,c,z]gesv.f

[Documentation correction]
correction in the description of the parameter NRHS (it's the number of columns
of B not A)

SRC/p[s,d]lared1d.f
SRC/p[s,d]lared2d.f

[Documentation correction]
[Julien]

The comments in the routines p[s,d]lared2d (where the initial vectors are
stored by row) were wrong (basically replace BYCOL by BYROW)

Some homogeneization among the 4 routines as well

SRC/p[s/d]lahrd.f

Although the Schur form returned by p[s/d]lahqr was correct (as tested by the
testing routine), the returned eigenvalues were not computed correctely. This
bug was reported by Interactive Supercompting (Thanks!). The bug was already
found by Greg Henry in March 2002 but the patch has never been released. Here
we go.

********************************************************************************

Rev: 2

********************************************************************************

Rev: 1

SCALAPACK/PBLAS/SRC/PBtools.h 		3/12/2002
 	Comment out CSYMM reference (line 57)

SCALAPACK/PBLAS/SRC/pblas.h 		3/15/2002
 	Added missing crot define

SCALAPACK/SRC/psdbtrf.f 		3/12/2002
 	Typo (DLACPY->SLACPY) in EXTERNAL declaration (line 374)

SCALAPACK/SRC/pcheevd.f 		3/25/2002
SCALAPACK/SRC/pzheevd.f 		
 	Correction to LRWORK (lines 117, 248) and INFO=0 return

SCALAPACK/TESTING/EIG/pcseptst.f 	3/15/2002
SCALAPACK/TESTING/EIG/pzseptst.f 
 	Correction to LHEEVDSIZE calculation (line 1064)


for more information, please visit: http://www.netlib.org/scalapack/errata.html#sourcecode


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