dsyev crashes on a simple matrix

ansobolev — Fri, 08 May 2026 13:24:19 GMT

Hi,

Thanks for solving the previous issue. I can confirm that it has indeed been fixed.

With MKL 2026.0 we encountered another issue: when trying to calculate the eigenvalues of a simple matrix with dsyev, we get floating divide by zero. The MWE is below:

program dsyev_example implicit none real*8 :: matrix(3,3), ev(3), work(8) integer :: info matrix(:, 1) = (/523.720904015851, 0.0, 0.0 /). matrix(:, 2) = (/-87.7269993344388, 509.765510517387, 0.0 /) matrix(:, 3) = (/-87.7269993344388, -114.410201478550, 509.765510517387 /) call dsyev( 'V', 'U', 3, matrix, 3, ev, work, 8, info ) print *, "Eigenvalues:" print *, ev end program dsyev_example

When compiling this with `-fpe0`, we get

forrtl: error (73): floating divide by zero Image PC Routine Line Source libc.so.6 0000126CD7845330 Unknown Unknown Unknown libmkl_core.so.3 0000126CD8EFA69F mkl_lapack_dlaq5 Unknown Unknown libmkl_core.so.3 0000126CD8FAB391 mkl_lapack_dsteqr Unknown Unknown libmkl_core.so.3 0000126CD8FB21C7 mkl_lapack_dsyev Unknown Unknown libmkl_intel_lp64 0000126CDFE6A1D6 dsyev_ Unknown Unknown a.out 00000000004053A5 Unknown Unknown Unknown a.out 000000000040528D Unknown Unknown Unknown libc.so.6 0000126CD782A1CA Unknown Unknown Unknown libc.so.6 0000126CD782A28B __libc_start_main Unknown Unknown a.out 00000000004051A5 Unknown Unknown Unknown

MKL 2025.3 and 2026.0 without `-mpe0` give the same correct results:

Eigenvalues: 319.854583405053 599.221603728736 624.175704956055

Thanks in advance.

Re: dsyev crashes on a simple matrix

Fengrui — Fri, 08 May 2026 16:55:12 GMT

Hi,

Thanks for reporting this issue. I can reproduce it on my side. The oneMKL 2025.3 release doesn't have this issue.

We are currently working on it. I will keep you posted.

Thanks,

Fengrui

Re: dsyev crashes on a simple matrix

Fengrui — Fri, 08 May 2026 22:47:42 GMT

It turns out to be a known issue. It has been fixed and fix will be included in the next oneMKL release.

Re: dsyev crashes on a simple matrix

ansobolev — Mon, 11 May 2026 07:56:11 GMT

Do you mean 2026.0.1 or 2026.1.0 by the next release?

Re: dsyev crashes on a simple matrix

Fengrui — Mon, 11 May 2026 14:25:25 GMT

According to the current plan, that would be the next update release, 2026.1.0.

topic Re: dsyev crashes on a simple matrix in Intel® oneAPI Math Kernel Library

dsyev crashes on a simple matrix

Re: dsyev crashes on a simple matrix

Re: dsyev crashes on a simple matrix

Re: dsyev crashes on a simple matrix

Re: dsyev crashes on a simple matrix