magmamic-1.4.0 : possible bug in dsyevd

Open discussion for MAGMA library (Matrix Algebra on GPU and Multicore Architectures)

magmamic-1.4.0 : possible bug in dsyevd

Postby karthee » Thu Feb 25, 2016 11:05 am


There seems to be a bug in the magmamic-1.4.0 when I call the dsyevd function.
This can be simulated by running the test program

./testing/testing_dsyevd -JV

It throws the following warning
Intel MKL ERROR: Parameter 4 was incorrect on entry to DLASCL.
and all the output Eigen values are zero.

This seems to be due to a bug in the src/dstedx.cpp in its call to lapackf77_dlanst function as shown below.
Code: Select all
orgnrm = lapackf77_dlanst("G", &m, &d[start], &e[start]);                   
                    lapackf77_dlascl("G", &izero, &izero, &orgnrm, &d_one, &m, &ione, &d[start], &m, info);
                    magma_int_t mm = m-1;
                    lapackf77_dlascl("G", &izero, &izero, &orgnrm, &d_one, &mm, &ione, &e[start], &mm, info);

I guess the dlanst does not take "G" as the first argument.
Once i replace the
Code: Select all
lapackf77_dlanst("G", &m, &d[start], &e[start]);

Code: Select all
lapackf77_dlanst("M", &m, &d[start], &e[start]);
it works fine.
Posts: 1
Joined: Thu Feb 25, 2016 10:46 am

Re: magmamic-1.4.0 : possible bug in dsyevd

Postby mgates3 » Fri Feb 26, 2016 4:43 pm

That is correct. Thank you and we'll fix it.
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Joined: Fri Jan 06, 2012 2:13 pm

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