bug0084 :: Bug Ming Gu

  • CORRECTED

  • bug reported by Ming Gu (UC Berkeley) through Jim Demmel

  • LAPACK driver routine infected: All SVD solvers when asked for singular values only. (Pathological matrix only)

  • bug is present in LAPACK since 3.1.1 and in Matlab 2010a and 2010b

  • For very specific matrices (given by Ming Gu), the DQDS code converges much slower than expected. The algorithm converges for these matrices un many more iterations than the LAPACK maximum number of iterations allow.

  • bug fix: (1) increase the maximum number of iterations in xlasq2, (2) fall back on Demmel/Kahan algorithm in case of nonconvergence of dqds.

  • corrected by Benjamin Lipschitz on Mon Oct 3rd 2011

bug0083 :: Bug in the testing of CHERFSX function

  • CORRECTED

  • bug reported by Olga Mitrofanova (Intel MKL team), on the LAPACK forum

  • see forum topic 2644

  • Test of CHERFSX function doesn’t work because there is an error in ../TESTING/LIN/cerrhex.f ( lines 284-330 ). This function uses the diagonal pivoting factorization of a Hermitian indefinite matrix instead of the diagonal pivoting factorization of a Hermitian indefinite packed matrix. When CHERFSX is included in conditional "IF( LSAMEN( 2, C2, HE ) ) THEN " the test works.

  • corrected by Julie on Mon Aug 15th 2011

bug0082 :: [CZ]laed2 Memory problems when COMPZ='I' in DSTEDC

  • CORRECTED

  • bug reported by Edward Smyth (NAG)

  • Added IF statement to prevent potential out of range errors with "K+1" indices.

  • corrected by Rodney on Wed Jun 21th 2011

bug0081 :: [SD]laed2 WORKSPACE size is wrong when NCVT = NRU = NCC = 0

  • CORRECTED

  • bug reported by Hatem Ltaief (KAUST)

  • Update Workspace requirement to 4*N because the routine call [SD]LASCL that requires a 4*N workspace.

  • corrected by Julie on Thu May 19th 2011

bug0080 :: [CZ]BDSQR WORKSPACE size is wrong when NCVT = NRU = NCC = 0

  • CORRECTED

  • bug reported by Hatem Ltaief (KAUST)

  • Update Workspace requirement to 4*N because the routine call [SD]LASCL that requires a 4*N workspace.

  • corrected by Julie on Thu May 19th 2011

bug0079 :: ILA[SDCZ]LR out of bound access in the DO LOOP for array A.

  • CORRECTED

  • bug detected by Julie

  • Change DO LOOP condition and add a IF inside the DO LOOP

  • corrected by Rodney on Tue April 21th 2011

bug0065 :: workspace queries not being used

  • CORRECTED

  • bug report by Clint Whaley on October 27th, 2010

  • DGESVD does not perform a workspace query on worker

  • functions such as DGELQF, but rather it hardwires in an assumption as

  • to LQF’s workspace requirements. This means that if LQF is changed,

  • GESVD breaks. This actually happens in ATLAS, because we provide a

  • faster GELQF, which sometimes uses extra workspace. For LAPACK itself,

  • it represents extra dependencies that don’t need to be there.

  • corrected by Julie on Mon Nov 7th 2011

bug0029 :: problem of WORKSPACE query with DSTEDC

  • CORRECTED

  • reported by Tiago Requeijo on Mon Mar 30 2009

  • see forum topic 1389

  • see also email from Edward Smyth on June 21st 2011

  • corrected by Rodney