LAPACK-3.2.1 errata file
updated on Fri April 4 2010
maintained by J. Langou, U. Colorado Denver
maintained by J. Langou, U. Tennessee

LAPACK-3.2.1 errata file
CLAPACK-3.2.1 errata file
BLACS-1.1.patch3 errata file
ScaLAPACK-1.8.0 errata file

Wishlist

Corrected in SVN -- to be released in 3.2.2
===========================================

(*) bug0014 :: CSYEQUB/ZSYEQUB/SSYEQUB/DSYEQUB/CHEEQUB/CHEEQUB: EXTERNAL and INTRINSIC list are not accurate (or not even present) 
(*) svn :: r660

    o bug report sent by Alexander V. Kobotov (Intel) on Mon, 6 Apr 2009 to "lapack@cs.utk.edu".
      "c(he/sy)equb: no slamch in external lists and lsame, intrinsics not described"
      Same problem for D and S versions and for the WORK array.
    o committed by Julien Langou (SVN revision 660 on Sun May 10 2009)

(*) bug0015 :: referencing WORK(1) and IWORK(1) when IJOB=0 in CTGSEN/DTGSEN/STGSEN/ZTGSEN contradicts header description
(*) svn :: r658,659

    o bug report sent by Alexander V. Kobotov (Intel) on Mon, 6 Apr 2009 to "lapack@cs.utk.edu".
      "(d/s)tgsen.f: iwork(1) always referenced: line 455: iwork( 1 ) = LIWMIN, documentation says that
      if IJOB=0 it shouldn't, so NULL pointer causes a segfault."
      Same problem for C and Z versions and for the WORK array.
    o committed by Julien Langou (SVN revision 658 and 659, on Sun May 10 2009)

(*) bug0016 :: problem in workspace query for CGEESX/DGEESX/SGEESX/ZGEESX
(*) svn :: r657

    o bug report sent by Alexander V. Kobotov (Intel) on Mon, 6 Apr 2009 to "lapack@cs.utk.edu".
      "(c/z)geesx: no lwork=-1 branch at all, info = -15 is returned while doing lquery."
      The S and D versions were not exiting after WORKSPACE query as well.
    o committed by Julien Langou (SVN revision 657, on Sun May 10 2009)

(*) bug0017 :: in CHBGST/ZHBGST, reference to uninitialized elements of RWORK in the DO 240 and DO 470 loops
(*) svn :: r656

    o patch given by Lawrence Mulholland (NAG) on Wed May 06 2009 
    o see forum topic 1408
    o committed by Julien Langou (SVN revision 656, on Sun May 10 2009)

(*) bug0019 :: 'make install' generates a "*** Error: Time for operations was zero" too easily
(*) bug0019 :: negative flop counts can be generated by 'make install'
(*) svn :: r693
    o reported by Sergei Steshenko on Thu Nov 20 2008
    o see: emails
    o committed by Julie Langou (SVN revision 693, on Fri Sep 11 2009)
    
(*) bug0021 :: in DGESDD, workspace query gives a value smaller than the minimal value given in the header to run the routine
(*) svn :: r649
    o reported by Guy Bencteux on Sat Dec 06 2008
    o see forum topic 846
    o committed by Julie Langou (SVN revision 649, on Tue Mar 17 2009)

(*) bug0023 :: SROTMG and DROTMG uses deprecated Fortran ASSIGN statement and assigned GOTO statement
(*) svn :: r691

    o reported by Marco Atzeri on Fri Mar 06 2009
    o see forum topic 1420
    o committed by Julie Langou (SVN revision 691, on Thu Sep 10 2009)
 
(*) bug0031 :: whitespace fix in comments
(*) svn :: r692

    o reported by "Jan" on Tue Jun 02 2009
    o see forum topic 1449
    o committed by Julie Langou (SVN revision 692, on Fri Sep 11 2009)

(*) bug0038 :: out of range element access in DLASET when using DGELSS
(*) svn :: r695

    o bug report sent by Tim Hopkins on Fri 31 Jul 2009
    o see forum topic 1582
    o committed by Julie Langou (SVN revision 695, on Fri Sep 25 2009)

(*) bug0041 :: printing format misuse in ./TESTING/EIG/[s,c,d,z]drvgbx.f
(*) svn :: r696

    o bug report sent by Michael Chuvelev (Intel) on Tue 29 Jul 2009 to "lapack@cs.utk.edu".
      "Bug in lapack-3.2.1/TESTING/EIG/zdrvgbx.f"
    o printing format misuse, this would possibly lead to a segmentation fault in case of errors in zgbsvxx. 
    o committed by Julien Langou (SVN revision 696, on Tue Sep 29 2009)
    
(*) bug0042 :: printing format misuse in ./TESTING/EIG/[s,c,d,z]drvgbx.f
(*) svn :: r697

    o bug report sent by Kevin Wadleigh on Tue 29 Sep 2009 to "lapack@cs.utk.edu".
      "LAPACK routine ieeeck.f and compiler optimizations"
    o The LAPACK function IEEECK should be modified to keep compilers from optimizing away the line
      NAN6 = NAN5*0.0
      and replacing it by NAN6 = 0.0.
      I've seen this happen using two different compilers at their default level of optimization. However, using
      NAN6 = NAN5*ZERO
      as in the attached file keeps this from happening.
    o committed by Julie Langou (SVN revision 697, on Wed Sep 30 2009)
    
(*) bug0043 :: VL, VU are referenced in lapack-3.2.1 dsyevr even if range.ne.'V'
(*) svn :: r699

   o bug report sent by Michael Chuvelev (Intel) on Wed, 14 Oct 2009 to "lapack@cs.utk.edu".
      "VL, VU are referenced in lapack-3.2.1 dsyevr even if range.ne.'V'"
   o committed by Julien Langou (SVN revision 699, on Tue Oct 20 2009)
    
(*) bug0044 :: bug in dsyevr.f when N = 1
(*) svn :: r704

   o bug report and fix sent by Ashutosh Mahajan (Mathematics and Computer Science Division of Argonne National Labs) on Fri, 11 Dec 2009 to "lapack@cs.utk.edu".
   o committed by Julien Langou (SVN revision 704, on Tue Dec 15 2009)
    
(*) bug0045 :: bug in dstemr.f when N = 2
(*) svn :: r705

   o bug report and fix sent by Ashutosh Mahajan (Mathematics and Computer Science Division of Argonne National Labs) on Thu, 10 Dec 2009 to "lapack@cs.utk.edu".
   o committed by Julien Langou (SVN revision 705, on Tue Dec 15 2009)
    
(*) bug0038 :: no LIWORK query in DGELSD
(*) svn :: r698

    o bug report from Mathew Cross on Tue 18 Aug 2009 
    o see forum topic 1601
    o committed by Julie Langou (SVN revision 698, on Thu Oct 20 2009)
    
(*) bug0046 :: Incorrectly documented RWORK workspace in ZGESDD
(*) svn :: r729

    o bug report from Zbigniew on Mon 15 Mar 2010 
    o see forum topic 1779
    o committed by Julie Langou (SVN revision 729, on Thu Mar 18 2010)

(*) bug0047 :: incorrect R/C parameter description in *gerfsx
(*) svn :: r726

    o bug report sent by Michael Chuvelev (Intel) on Wed, 1 Mar 2010 to "lapack@cs.utk.edu".
    o bug fix sent by James Demmel
       "R/C are input only by their usage"
       "there's no FACT parameter in these routines"
    o committed by Julie Langou (SVN revision r726, on Tue Mar 9 2010)
   
(*) bug0048 :: Hanging could occur in *gebal if a NaN is in input matrix.
(*) svn :: r730

    o bug report and fix sent by Alexander Kobotov (Intel) on Wed, 3 Feb 2010 to "lapack@cs.utk.edu".
    o committed by Julie Langou (SVN revision r730, on Tue Mar 9 2010)
      
(*) bug0049 :: output parameter GIVPTR stays uninitialized in case of quick exit (n.eq.0) or if the rank-1 modifier is small enough in *laed8.
(*) svn :: r731

    o bug report and fix sent by Alexander Kobotov (Intel) on Wed, 3 Feb 2010 to "lapack@cs.utk.edu".
    o committed by Julie Langou (SVN revision r731, on Tue Mar 9 2010)
    
(*) bug0050 :: An extra argument after matrix A lines 348-249 in STFSM.f causes a crash of SGEMM call.
(*) svn :: r732

    o bug report and fix sent by Alexander Kobotov (Intel) on Wed, 3 Feb 2010 to "lapack@cs.utk.edu".
    o committed by Julie Langou (SVN revision r732, on Tue Mar 9 2010)
    
(*) bug0051 :: INFO=N+2 in xDGGES due to too stringent threshold in xTGEX2.
(*) svn :: r735

    o bug report sent by Ondra Kamenik on Tue Mar 16, 2010
    o see forum topic 1783
    o We have changed xLARFG to xLARFP in xGEQR2. xGEQR2 is used by xDGGES. The
      matrices are therefore different (although all of them are correct.) However
      for the matrix generated by xLARFP, xTGEX2 exceeds the THRES value by 10%,
      causing an error flag. We decided to increase THRES by a factor of 2.
      Although the bug was triggered by the change from xLARFG to xLARFP, XLARFP 
      is not really at guilt.
    o confirmed by Julie Langou on Thu Mar 18 2010
    o fix provided by Guillaume Revy and Jim Demmel
    o committed by Julien Langou (SVN revision r735, on Thu Apr 2 2010)

(*) bug0052 :: Incorrect NRHS parameter in call to ?SYTRS from ?la_{po,sy,he}rfsx_extended.f.
(*) svn :: r736

    o bug report and fix sent by Michael Chuvelev (Intel) on Fri, 2 Apr 2010 to "lapack@cs.utk.edu".
    o committed by Julie Langou (SVN revision r736, on Fri, Apr 2 2010) 
    
(*) bug0053 :: Fix external declaration issue in testing suite file: cebchvxx.f
(*) svn :: r738

    o bug report and fix sent by Michael Chuvelev (Intel) on Fri, 5 Apr 2010 to "lapack@cs.utk.edu".
    o committed by Julie Langou (SVN revision r738, on Fri, Apr 5 2010)
    
(*) bug0054 :: Fix comment some of the argument descriptions have the wrong type.
(*) svn :: r739

    o bug report sent by Paul Roberts (NAG) on Fri, 12 Apr 2010 to "lapack@cs.utk.edu".
    o committed by Julie Langou (SVN revision r739, on Fri, Apr 12 2010)
        
(*) bug0055 :: Missing arguments descriptions of work and uplo in [csz]syequb
(*) svn :: r740

    o bug report sent by Paul Roberts (NAG) on Fri, 13 Apr 2010 to "lapack@cs.utk.edu".
    o committed by Julie Langou (SVN revision r740, on Fri, Apr 13 2010)
    
(*) bug0058 :: variable N0 in xLASQ3 is INPUT/OUTPUT. (The comments said INPUT.)
(*) svn :: r750

    o  bug report and bug fix are from William Gandler (NIH/CIT) on October 16, 2009; April 23,
2010; May 01, 2010, May 03, 2010. to "lapack@cs.utk.edu".
    o committed by Julie Langou (SVN revision r750, on Fri, May 27 2010)

(*) bug0025 :: serious problem in DGESDD: DGESDD returns negative singular values with INFO = 0

    o reported by Guy Bencteux on Sat Dec 06 2008
    o see forum topic 847
    o Julie : CANNOT REPRODUCE THE PROBLEM
    
    o on Sat Jun 19 2010, Bruno Pin¨on from ESIAL, reported another matrix with the same problems
    o see  forum topic 1868
    o we can reproduce the problem with on MacOS with gfortran reference LAPACK
     and vecLib BLAS, we can not reproduce the problem with reference LAPACK and reference BLAS.
    o A patch has been proposed by Julien Langou. (See forum topic 1868.)
    o Note: there is strong evidence that the bug of Guy Bencteux and this one
     are the same, although we were never able to reproduce Guy's problem. So
     we assume Guy's problem gone! 
    
(*) bug0059 ::    ZGELSD crashes on large matrices (eq M=N=NHRS>=88), if real workspace allocated exactly as reported on workspace query.
(*) svn :: r765

    o bug report and fix sent by Alexander Kobotov (Intel) on Wed, 23 June 2010 to "lapack@cs.utk.edu".
    o Root cause is wrong estimation of real workspace size in ZLALSA (on path zgelsd->zlalsd->zlalsa).
      It assumes that RWORK array length should be max( N, (SMLSZ+1)*NRHS*3 ), where SMLSIZ=25.
      But in fact the function calls zlals0 which requires RWORK to be ( K*(1+NRHS) + 2*NRHS ), 
      where K could be as large as number of columns in matrix A.
      The same is actual for CGELSD.
    o committed by Julie Langou (SVN revision r765, on Thu, June 24 2010)
    
(*) bug0060 ::    Bug in dtgsy2, missing IWORK call
(*) svn :: r767

    o bug report and fix sent by Vasile Sima on 24 Feb 2009 to "lapack@cs.utk.edu".
    o The error is that "IWORK" must appear in the line 640.  (It was included in the 1999 version.)
      Note that the statement IE = ( I+1 ) - 1 is strange;  also, in other similar place, IWORK is used like below.
    o committed by Julie Langou (SVN revision r767, on Thu, June 24 2010)


Confirmed problems -- bug needs to be fixed!
============================================

(*) bug0020 :: in xGESDD, workspace query can overflow for large matrices

    o reported by Stephan Ripke (Broad Institute, Boston) on Thu May 21 2009
    o confirmed by Julien Langou on Thu May 21 2009
    o see forum topic 1418

(*) bug0022 :: workspace query bug with DGEJSV (when only left or right singular vectors desired)

    o reported by Allin Cottrell on Tue Jan 15 2009
    o confirmed by Julien Langou on Fri Jan 30 2009
    o see forum topic 866
    o all information sent to Zlatko Drmac

(*) bug0024 :: the notation A' is confusing for complex matrices. Does A' stand for A transpose of A Hermitian transpose?

    o reported by Clint Whaley early July 2009
    o LAPACK is not consistent in it use of the notation for transpose and Hermitian transpose.
    o The use of LAPACK A' is not consistent with the BLAS useage.
    o We note that the Matlab/Scilab/Octave convention is A' stands for
      "conjugate transpose" and A.' stands for "transpose".
    o In the Z routines, LAPACK uses the notation A' 669 times, it means "conjugate
      transpose" most of the time but it means "transpose" a few times (maybe
      10 times max, for BLAS-like routines). The notation A**H, A**T, A**N is
      used 549 times, The notation A^T, A^N, A^H 19 times. (This is just for
      the Z routines.)
    o see Julien's emails
    o vote on the lapackers mailing list:
          A**T (or A^T) and A**H (or A^H): Clint Whaley, Jim Demmel, Sven Hammarling, Antoine Petitet, Daniel Kressner
          A' (for A**H) and A.' for (A**T): Julien Langou
      (I love to be that supported by the lapackers!)

(*) bug0057 :: Non-eigenvectors from DGEEV, problem in balancing

    o bug report sent by Numpy team on April 22nd
    o see forum topic 1818
    o see follow-up on lapackers on April 22nd from Jim "bug in DGEHRD"
    "The balancing is choosing to scale some rows/columns by factors like 1e18,
which rather amplifies tiny rounding errors in the (presumably correctly)
computed eigenvectors of the balanced matrix, when balancing is undone at the end.
The expert driver interface dgeevx would let the user disable balancing, until
we figure out whether this is a bug or a feature, I'm not sure which."



Bug reports -- bug needs to be confirmed!
=========================================


(*) bug0026 :: problem when playing with DGEEV and gfortran optimization flags

    o reported by Pauli Virtanen (scipy team) on Sat Dec 06 2008 (email to lapack@cs.utk.edu)
    o see: email from Pauli Virtanen
      see: http://scipy.org/scipy/scipy/ticket/709

(*) bug0027 :: misleading comment in the header of DGHEQZ, the 2x2 block of the real Schur form are not as claimed

    o reported by Vasile Sima on Tue Jan 27 2009
    o see: email from Vasile
    o more information:
      more specifically Vasile is reporting that the comments:

*          [...] H contains the upper quasi-triangular
*          matrix S from the generalized Schur factorization;
*          2-by-2 diagonal blocks (corresponding to complex conjugate
*          pairs of eigenvalues) are returned in standard form, with
*          H(i,i) = H(i+1,i+1) and H(i+1,i)*H(i,i+1) < 0.

     are not correct

(*) bug0028 :: failure of convergence of DHGEQZ for some specific matrix pencils

    o reported by Vasile Sima on Thu Jan 22 2009
    o see: email from Vasile
    o more information at: lapack known issues
     
(*) bug0029 :: problem of WORKSPACE query with DSTEDC

    o reported by Tiago Requeijo on Mon Mar 30 2009
    o see forum topic 1389
    o Julie : CANNOT REPRODUCE THE PROBLEM

(*) bug0030 :: line 641 of DTGSY2 (present as well in STGSY2, ZTGSY2, CTGSY2)

    o reported by Zbigniew Leyk (College Station, TX) on Mon Jun 01, 2009
    o see forum topic 1445

(*) bug0032 :: matrix splitting problem with dstebz and sstebz

    o bug report sent by Phil DeMier (IBM) on Mon 29 Jun 2009 to "lapack@cs.utk.edu".
      "matrix splitting problem with dstebz and sstebz"
    o see Phil DeMier's email and Phil DeMier's test code

(*) bug0033 :: failure of zheevd on a specific matrix

    o bug report sent by Cezary Sliwa (Instytut Fizyki PAN, Poland) on Thu 2 Jul 2009 to "lapack@cs.utk.edu".
    o see Cezary Sliwa's test code, Cezary Sliwa's matrix, and
      Cezary Sliwa's email.

(*) bug0034 :: comments in SSPTRF not correct 

    o clarification asked by "sarnath" on Thu Jul 02 2009
    o confirmation of bug by "sarnath" and Julien Langou on Fri Jul 03 2009
    o The statement "JMAX is the column-index of the largest off-diagonal element in row IMAX" is not correct
    o see forum topic 1553

(*) bug0035 :: dlarfb.f and likes

    o bug report sent by Michael Chuvelev (Intel) on Tue 21 Jul 2009 to "lapack@cs.utk.edu".
      "Bug in LAPACK 3.2 dlarfb.f and likes"
    o see Michael Chuvelev and Julie's emails, q.dat,
      tau.dat, and test_dorgql.f

(*) bug0036 :: scaling in xSTEQR, xSTERF

    o bug report sent by Pat Quillen on Fri 24 Jul 2009 to "lapack@cs.utk.edu".
      "Scaling in xSTEQR, xSTERF"
    o see Pat Quillen's email, quillen dsteqr.f.

(*) bug0037 :: xLARFP and scaling

    o bug report sent by Pat Quillen on Wed 29 Jul 2009 to "lapack@cs.utk.edu".
      "xLARFP and scaling"
    o see Pat Quillen's email, and quillen dlarfp2.f,
    o see Sven Hammarling's email
    o see Pat Quillen's email, quillen dlarfp3.f, and quillen dlarf2.f.

(*) bug0039 :: faulty workspace queries in GEESX

    o bug report from Mathew Cross on Tue 18 Aug 2009 
    o see forum topic 1602

(*) bug0040 :: Q referenced in real TGSENs when WANTQ .FALSE.

    o bug report from Mathew Cross on Tue 18 Aug 2009 
    o see forum topic 1604
    
(*) bug0056 ::  Non-orthogonal eigenvectors returned from DSYEVR

    o bug report sent by by Scipy team on April 22nd
    o see  LAPACK Mailing list msg 874
    o Julie cannot reproduce the problem on her machine with 3.2.1 and Ref BLAS

Deprecated routines
===================

(*) dead code :: xLAHRD is now replaced by xLAHR2, xLAHRD is a dead code since LAPACK 3.1

    o xLAHRD will be removed at some point in the future from the distribution

Previous Errata (LAPACK 3.2.x)
==============================

   o Fri Apr 02 2010 (LAPACK-3.2.1)
   o Thu Oct 15 2009 (LAPACK-3.2.1)
   o Sat Oct 10 2009 (LAPACK-3.2.1)
   o Thu Oct 01 2009 (LAPACK-3.2.1)
   o Tue Sep 29 2009 (LAPACK-3.2.1)
   o Fri Sep 25 2009 (LAPACK-3.2.1)
   o Mon Sep 11 2009 (LAPACK-3.2.1)
   o Mon Sep 07 2009 (LAPACK-3.2.1)
   o Sun May 10 2009 (LAPACK-3.2.1)
   o Fri Apr 17 2009 (LAPACK-3.2.1)
   o Tue Mar 10 2009 (LAPACK-3.2.0)
   o Tue Mar 03 2009 (LAPACK-3.2.0)
   o Mon Mar 02 2009 (LAPACK-3.2.0)
   o Mon Feb 01 2009 (LAPACK-3.2.0)