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[Lapack] Error in the reference implementation of DGEMV

Hey! That was a tricky one though ... It's not what I would have expected 
as well! Thanks a lot Sven. Julien.

On Wed, 6 Jan 2010, Sven Hammarling wrote:

Dear Erik,

The specifications for the Level 2 BLAS are given in:

J. J. Dongarra, J. Du Croz, S. Hammarling, and R. J. Hanson. An extended
set of FORTRAN Basic Linear Algebra Subprograms. ACM Trans. Math.
Software, 14:1?32, 399, 1988.

and on page 5 we have:

"Note that it is permissible to call the routines with M or N = 0, in
which case the routines exit immediately without referencing their
vector or matrix arguments."

so, although it might not be what you expect, the reference
implementation is behaving correctly.

Best wishes,

Sven Hammarling.
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