updated on October 11 2012

maintained by Julien Langou, U. Colorado Denver and Julie Langou, U. Tennessee

RED means BUG WAS CONFIRMED but IT IS STILL HERE

MAROON means BUG WAS NOT CONFIRMED

GREEN means BUG WAS CORRECTED :

bug110 :: possible infinite loop in ZLARTG when input vector has NaN

  • CONFIRMED

  • Present in LAPACK 3.4.2

  • Bug report by Mark Hoemmen and Jack Poulson

  • See http://icl.cs.utk.edu/lapack-forum/viewtopic.php?f=5&t=3267&p=9067

  • Mark Hoemmen writes: Jack Poulson found that ZLARTG has an infinite loop related

  • to NaN .EQ. 0. It’s the line below "ELSE IF( SCALE.LE.SAFMN2 )" between 10 and

  • 20. When G is NaN, then the loop goes forever.

bug0109 :: [xDRVRFP] Test was failing

  • CORRECTED, rev 1425

  • Present in LAPACK 3.4.2

  • bug report by Hong Xu (INTEL) on July 21st

  • Patch sent by Hong Xu (INTEL)

  • In the input parameter checking, LDZ was not checked correctly

  • LDZ was checked against M instead of N essentially

  • Corrected by Julien on July 22 2013

bug0108 :: [xDRVRFP] Test was failing

  • CORRECTED, rev 1416

  • Present in LAPACK 3.4.2

  • bug report by Elena Ivanova (ORACLE)

  • Patch sent by Elena Ivanova (ORACLE)

  • add MAX() to ensure index is at least 1

  • Corrected by Rodney on June 27 2013

bug0107 :: [CSD routines] fixed array index problems

  • CORRECTED, rev 1414

  • Present in LAPACK 3.4.2

  • add MAX() to ensure index is at least 1

  • this fixes array bounds violations in the test suite when array bounds checking is enabled

  • Corrected by Rodney on June 04 2013

bug0106 :: [xGEBAL] very large backward error for certain Hessenberg matrices (Watkins)

  • CORRECTED, rev 1413

  • Present in LAPACK 3.4.2

  • bug report on the forum topic 4221

  • Now using 2-norm to compute vector norms of row and column for balancing algorithm.

  • This seems to fix problems with balancing causing very large backward error for certain

  • Hessenberg matrices, including the often cited example of Watkins.

  • Corrected by Bradley Lowery, Rodney James, Julien Langou on May 26 2013

bug0105 :: [LAPACKE] lapacke.h problem

  • CORRECTED, rev 1388

  • Present in LAPACKE 3.4.2

  • bug report on the forum topic 4221

  • Patch sent by bmoloney

  • A few C++ library includes are inside of the 'extern C block which causes many template with C

  • linkage errors when the header is included in a C++ file.

  • Corrected by Julie on April 03 2013

bug0104 :: dgeqp3 fall over when asked to do a factorization of the last two columns.

  • CORRECTED, rev 1385

  • Present in LAPACK 3.4.2

  • bug report by Tyrone Rees (STFC Rutherford Appleton Laboratory) on March 22 2013

  • Patch sent by Tyrone Rees

  • Corrected by Rodney on March 22 2013

bug0103 :: [dlasd4/slasd4] fixes bug where TAU2 can be uninitialized.

  • CORRECTED, rev 1384

  • Present in LAPACK 3.4.2

  • bug report by Sergey Kuznetsov (INTEL) on March 15 2013

  • Patch sent by Sergey Kuznetsov

  • Corrected by Rodney on March 22 2013

bug0102 :: convergence problem with some particular pencils in xGGEV

  • CORRECTED, rev 1351

  • Present in LAPACK 3.4.2

  • bug report by Mathworks on October 19 2012

  • Patch sent by Mathworks

  • Corrected by Rodney on Thu Oct 19

bug0101 :: [S,D, C, Z]hsein: NaN in H can cause an infinite loop

  • CORRECTED, rev 1350

  • Present in LAPACK 3.4.2

  • bug report by Alexander Kobotov (INTEL) on October 3 2012

  • See forum topic 3928

  • added check for NaN after the norm of each block of H is computed

  • if NaN is detected, returns with INFO=-6 (H is the 6th parameter)

  • Corrected by Rodney on Thu Oct 11

bug0061 :: zgehrd.f is overflowing

  • CONFIRMED

  • bug report by Victor Liu on Tuesday August 03rd, 2010

  • zgehrd.f is overflowing the maximum size in bytes of the largest array that

  • can be put on the stack with gfortran (⇒ leads ,e.g., to non-reproducible and uncorrect execution

  • of zgeev in multithreaded context

  • lapackers involved in the bug fix process: Julie and Julien Langou and Mathieu Faverge

  • bug fix by Victor Liu on Wednesday August 04th, 2010

  • see forum topic 1930

  • two outstanding issues: (1) how do we go to fix this?, (2) more LAPACK subroutines might be concerned.

bug0057 :: Non-eigenvectors from DGEEV, problem in balancing

  • CONFIRMED

  • bug report sent by Numpy team on April 22nd, 2010

  • see forum topic 1818

  • 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."

bug0056 :: Non-orthogonal eigenvectors returned from DSYEVR

  • CONFIRMED

  • bug report sent by Scipy team on April 22nd

  • see LAPACK Mailing list msg 874

  • Confirmed by Rodney on Tue, 17 Feb 2011

  • " I can reproduce similar problems that the user encountered with non-orthogonal eigenvectors when only

  • a few eigenvalues are requested. This also happens with SSYEVR. If I set ABSTOL to SLAMCH(Safe minimum),

  • the problem goes away in SSYEVR, and improves with DSYEVR but does not completely go away."

bug0033 :: failure of zheevd on a specific matrix

bug0032 :: matrix splitting problem with dstebz and sstebz

  • CONFIRMED

  • bug report sent by Phil DeMier (IBM) on Mon 29 Jun 2009 to "lapack@cs.utk.edu". "matrix splitting problem with dstebz and sstebz"

  • see Phil DeMier’s email and Phil DeMier’s test code

  • Confirmed by Rodney on Tue, 17 Feb 2011