RE: [AMBER-Developers] Current parallel test failures in the tree

From: Ross Walker <ross.rosswalker.co.uk>
Date: Thu, 25 Mar 2010 10:26:04 -0700

Hi Lin,

> but why it seems no problem for new intel fortran compiler version 11
> and
> still get the same result compared with *.save file, and it will crash
> on
> ifort 10 according to ross's test.

It is a subtle function of memory layout. Compilers will place arrays in
different locations and the probability that these locations contain zero
varies. Additionally some versions of the compiler begin by zeroing all the
memory at start up in order to perform certain optimizations while others do
not. Thus when you get 'undefined' behavior that comes and goes with
different compilers it almost always means there is a bug in the code
related to an unitialized array or more often memory allocation / array
over/underrun issues.

All the best
Ross


/\
\/
|\oss Walker

| Assistant Research Professor |
| San Diego Supercomputer Center |
| Tel: +1 858 822 0854 | EMail:- ross.rosswalker.co.uk |
| http://www.rosswalker.co.uk | http://www.wmd-lab.org/ |

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Received on Thu Mar 25 2010 - 10:30:08 PDT
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