[petsc-dev] Problem in VecAXPY

[Barry Smith]

On Jun 16, 2010, at 8:26 PM, Lisandro Dalcin wrote:

> 
> 
> On 16 June 2010 21:24, Barry Smith <bsmith at mcs.anl.gov> wrote:
> 
>    As someone else pointed out the BLAS call cannot have the two arguments be the same (because it is Fortran) so we've have to handle that case with additional ugly checks if we did support the same vector.
> 
> 
> We could still use VecScale.... Too much black magic?
> 

   Yes we could. But then do we support the same arguments in VecAYPX(), and VecWAXPY() and VecAXPBY(). Do we have different pieces of code depending on which vectors are the same as other vectors? Otherwise we couldn't use const on arrays etc. I don't see the tiny advantage of having a more general interface outweighs more complicated code.

    Barry

> -- 
> Lisandro Dalcin
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