RE: [AMBER-Developers] more on pme_setup problem

From: Ross Walker <>
Date: Wed, 10 Mar 2010 08:48:14 -0800

FYI This works fine with 11.1.064 so I think it really is something in the
very latest version of ifort.

> -----Original Message-----
> From: [mailto:amber-developers-
>] On Behalf Of case
> Sent: Wednesday, March 10, 2010 8:13 AM
> To:
> Subject: [AMBER-Developers] more on pme_setup problem
> I am ordinarily reluctant to assign problems as "compiler errors" since
> it
> is not uncommon for there to be subtle errors in our code that are only
> exposed with certain compilers or options.
> In this case, however, I am somewhat more willing to blame Intel. Here
> are a few additional points of information:
> 1. It doesn't seem to be related to any recent code change: ifort 11.1
> (069)
> gives the same failure for amber10 as for the amber11 in CVS.
> 2. In addition to working for various flavors of ifort 10, the current
> code also works for ifort 11.0 (081) and ifort 11.1 (046). I am
> working to
> narrow down further when the problem appears [known to fail for ifort
> 11.1
> (069), but I've not tested intermediate versions.]
> This kind of explains why all this has only come up recently: it is
> only
> quite recent versions of ifort that exhibit this behavior. It seems to
> be
> related to the fact that pmemd is using a common block to pack module
> variables in a certain storage order. [I'm not saying the code is
> wrong, just
> that this somehow seems to a part of the symptom.]
> If someone wants to look at this, here's a good question to start with:
> why does the use of "natom" in the check_neutral() subroutine in
> pme_setup.fpp
> not trigger a problem, whereas the very similar use in
> vdw_correct_setup()
> does trigger the error? [Note: I've played with removing compiler
> optimzations, with no success.]
> However, it is not really a "solution" (to use Dan's phrase) to just
> tell
> people to go get an older compiler from intel, since (as far as I can
> see from
> Intel's web site) that is not such an easy thing to do. If someone
> knows how
> this can be done, please post, and we'll get it on the wiki or the web
> site.
> ....more later....dac
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Received on Wed Mar 10 2010 - 09:00:05 PST
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