SORMRQ fails erroneously when LDA < M

[Paul_F_]

I've encountered a bug after updating from a fairly old (~2013) version of MKL to the latest version that SORMRQ now fails if LDA < M, even though the only stated constraint is LDA >= K.

It seems to fail for any set of parameters where M > K/LDA.

DORMRQ does not appear to experience this failure when the same parameters are used.

For a specific example, using has parameters (SIDE='L', TRANS='T', M=256, N=251, K=251, LDA=251, LDC=256), I get the following for a work query (LWORK=-1):

"Intel MKL ERROR: Parameter 7 was incorrect on entry to SORMRQ."

I get the same thing when trying to call the function through the LAPACKE interface.

This looks like a bug in MKL. Can anyone else confirm?

[mecej4]

I can confirm that (after adaptation to MKL) the example at http://www.nag.com/numeric/fl/nagdoc_fl25/html/f08/f08ckf.html works correctly in double precision and fails in single precision. In the latter case, the failure is accompanied by the message "Intel MKL ERROR: Parameter 7 was incorrect on entry to SORMRQ". Note that, in this example, LDA = M, and the work array WORK was already allocated to a size much larger than needed for SORMRQ because the same array is used as the work array for an earlier call to SGERQF.