Opened 10 years ago

Last modified 3 years ago

#258 new bug

Reducing MPI_REAL16's

Reported by: goodell Owned by:
Priority: minor Milestone: future
Component: mpich Keywords:
Cc: jhammond

Description (last modified by balaji)

Yet another wacky inter-language issue to check on...

Begin forwarded message:

> From: Jeff Squyres <>
> Date: October 29, 2008 Oct 29 11:25:21 AM CDT
> To: Dave Goodell <>
> Subject: Reducing MPI_REAL16's
> Yo Dave --
> In the genre of obscure MPI bugs...  Will MPICH2 also have this
> same issue?
> See comments 1, 2, and 4 in particular.
> --
> Jeff Squyres
> Cisco Systems

Change History (7)

comment:1 Changed 10 years ago by Dave Goodell

  • id set to 258

This message has 0 attachment(s)

comment:2 Changed 10 years ago by thakur

Yes, this came up in old req #4004, which includes a discussion with Intel on the topic.

comment:3 Changed 10 years ago by gropp

A possible fix for this is to use Fortran to process the Fortran-specific types, including REAL16 and COMPLEX32. The code might be faster as well.

What we might want to do is to change the way we invoke the routines for the predefined operations on the predefined types; we could have something like

if (predefinedop)

fcn = op->functionmap[datatype];
if (fcn) err = (*fcn)( ... ))
else err = opundefined

The "functionmap" will be a new field in the struct that MPI_Op refers to.

This preserves the lazy loading (executables only include the routines for the operations that are included). An additional benefit is that the operation codes might be faster - some compilers don't like to optimize big routines. It also can simplify supporting C++ types that might be added in MPI 2.2/3.0.

comment:4 Changed 9 years ago by balaji

  • Milestone set to future
  • Priority changed from major to minor
  • Summary changed from Fwd: Reducing MPI_REAL16's to Reducing MPI_REAL16's

comment:5 Changed 7 years ago by balaji

  • Owner set to gropp
  • Status changed from new to assigned

comment:6 Changed 5 years ago by balaji

  • Description modified (diff)
  • Owner gropp deleted
  • Status changed from assigned to new

comment:7 Changed 3 years ago by jhammond

  • Cc jhammond added
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