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Subject: Re: [OMPI users] MPI_Allreduce on local machine
From: Hugo Gagnon (sourceforge.openmpi_at_[hidden])
Date: 2010-07-27 11:21:44


I appreciate your replies but my question has to do with the function
MPI_Allreduce of OpenMPI built on a Mac OSX 10.6 with ifort (intel
fortran compiler).

-- 
  Hugo Gagnon
On Tue, 27 Jul 2010 13:23 +0100, "Anton Shterenlikht"
<mexas_at_[hidden]> wrote:
> On Tue, Jul 27, 2010 at 08:11:39AM -0400, Jeff Squyres wrote:
> > On Jul 26, 2010, at 11:06 PM, Hugo Gagnon wrote:
> > 
> > >   8         integer, parameter :: dp = kind(1.d0)
> > >   9         real(kind=dp) :: inside(5), outside(5)
> > 
> > I'm not a fortran expert -- is kind(1.d0) really double precision?  According to http://gcc.gnu.org/onlinedocs/gcc-3.4.6/g77/Kind-Notation.html, kind(2) is double precision (but that's for a different compiler, and I don't quite grok the ".d0" notation).
> 
> *quote*
> kind (x) has type default integer and value equal to the kind
> type parameter value of x.
> *end quote*
> 
> p. 161 from Metcalf et al (2007) Fortran 95/2003 explained.
> 
> % cat tmp.f90
>         program z
> 
>         integer, parameter :: dp = kind(1.d0)
>         real(kind=dp) :: inside(5), outside(5)
> 
>         write(*,*)dp
> 
>         end program z
> % g95 -L/usr/local/lib tmp.f90
> % ./a.out
>  8
> % 
> 
> Kind 8 is (on most arch) 8-byte real, i.e. typically
> double precision.
> 
> -- 
> Anton Shterenlikht
> Room 2.6, Queen's Building
> Mech Eng Dept
> Bristol University
> University Walk, Bristol BS8 1TR, UK
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-- 
  Hugo Gagnon